Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Uncertainty of Non-Destructive InteriorImaging Techniques
Laszlo Varga
University of Szeged, HungaryDepartment of Image Processing and Computer Graphics
19 July 2017
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Interior imaging techniques
Some imaging techniques
• Computer Tomography
• Magnetic Resonance Imaging (MRI)
• Positron Emission Tomography,
• Ultrasound imaging
• Electric Impedance Tomography.
Common properties
• Gathers secondary information,
• Uses mathematical tools forreconstruction,
• Data gathering has some cost.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Interior imaging techniques
Some imaging techniques
• Computer Tomography
• Magnetic Resonance Imaging (MRI)
• Positron Emission Tomography,
• Ultrasound imaging
• Electric Impedance Tomography.
Common properties
• Gathers secondary information,
• Uses mathematical tools forreconstruction,
• Data gathering has some cost.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Interior imaging techniques
Some imaging techniques
• Computer Tomography
• Magnetic Resonance Imaging (MRI)
• Positron Emission Tomography,
• Ultrasound imaging
• Electric Impedance Tomography.
Common properties
• Gathers secondary information,
• Uses mathematical tools forreconstruction,
• Data gathering has some cost.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Interior imaging techniques
Some imaging techniques
• Computer Tomography
• Magnetic Resonance Imaging (MRI)
• Positron Emission Tomography,
• Ultrasound imaging
• Electric Impedance Tomography.
Common properties
• Gathers secondary information,
• Uses mathematical tools forreconstruction,
• Data gathering has some cost.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Interior imaging techniques
Some imaging techniques
• Computer Tomography
• Magnetic Resonance Imaging (MRI)
• Positron Emission Tomography,
• Ultrasound imaging
• Electric Impedance Tomography.
Common properties
• Gathers secondary information,
• Uses mathematical tools forreconstruction,
• Data gathering has some cost.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Interior imaging techniques
Some imaging techniques
• Computer Tomography
• Magnetic Resonance Imaging (MRI)
• Positron Emission Tomography,
• Ultrasound imaging
• Electric Impedance Tomography.
Common properties
• Gathers secondary information,
• Uses mathematical tools forreconstruction,
• Data gathering has some cost.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Interior imaging techniques
Some imaging techniques
• Computer Tomography
• Magnetic Resonance Imaging (MRI)
• Positron Emission Tomography,
• Ultrasound imaging
• Electric Impedance Tomography.
Common properties
• Gathers secondary information,
• Uses mathematical tools forreconstruction,
• Data gathering has some cost.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Transmission tomography
• We are interested in theinner structure of somegiven object.
• We can measure theprojections of the object ofstudy (the densities of theobject along the path ofsome projection beams).
• The goal is to reconstructthe original structure from agiven set of projections.
• Usually done slice-by-slice.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Transmission tomography
• We are interested in theinner structure of somegiven object.
• We can measure theprojections of the object ofstudy (the densities of theobject along the path ofsome projection beams).
• The goal is to reconstructthe original structure from agiven set of projections.
• Usually done slice-by-slice.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Transmission tomography
• We are interested in theinner structure of somegiven object.
• We can measure theprojections of the object ofstudy (the densities of theobject along the path ofsome projection beams).
• The goal is to reconstructthe original structure from agiven set of projections.
• Usually done slice-by-slice.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Transmission tomography
• We are interested in theinner structure of somegiven object.
• We can measure theprojections of the object ofstudy (the densities of theobject along the path ofsome projection beams).
• The goal is to reconstructthe original structure from agiven set of projections.
• Usually done slice-by-slice.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Transmission tomography
• We are interested in theinner structure of somegiven object.
• We can measure theprojections of the object ofstudy (the densities of theobject along the path ofsome projection beams).
• The goal is to reconstructthe original structure from agiven set of projections.
• Usually done slice-by-slice.
Object ofstudy
Projection
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Transmission tomography
• The object of study is represented by a function f (u, v).
f : R2 → R
• We take the line integrals of the image(Radon-Transform).
[Rf ](α, t) =
∫ ∞−∞
f (t cos(α)−q sin(α), t sin(α)+q cos(α)) dq
• We are looking for an f ′(u, v) function that has the sameprojections as the original f (u, v).
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Formulation of the reconstructionproblem
• We assume a discrete representation of the object of study(i.e., it is represented on an n × n sized discrete image).
• The projections are given by the integrals of the imagealong a set of straight lines.
x1 x2 x3 x4
x5 x6 x7 x8
x9 x10 x11 x12
x13 x14 x15 x16 Source
Detector
xjbi
bi+1
ai,j
ai+1,j
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Projections and Sinogram
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Transmission tomography
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Transmission tomography
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Problem with reconstruction
This was the ideal case, which is not so common.
Taking many projection of good quality has high costs.
• High radiation dosage.
• High acquisition time.
• Simply costs much money.
Consequences of the limitations
• Noise in the projections.
• Limited amount of projections.
• Leading to uncertainty of the data.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Problem with reconstruction
This was the ideal case, which is not so common.
Taking many projection of good quality has high costs.
• High radiation dosage.
• High acquisition time.
• Simply costs much money.
Consequences of the limitations
• Noise in the projections.
• Limited amount of projections.
• Leading to uncertainty of the data.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Problem with reconstruction
This was the ideal case, which is not so common.
Taking many projection of good quality has high costs.
• High radiation dosage.
• High acquisition time.
• Simply costs much money.
Consequences of the limitations
• Noise in the projections.
• Limited amount of projections.
• Leading to uncertainty of the data.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Problem with reconstruction
This was the ideal case, which is not so common.
Taking many projection of good quality has high costs.
• High radiation dosage.
• High acquisition time.
• Simply costs much money.
Consequences of the limitations
• Noise in the projections.
• Limited amount of projections.
• Leading to uncertainty of the data.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Problem with reconstruction
This was the ideal case, which is not so common.
Taking many projection of good quality has high costs.
• High radiation dosage.
• High acquisition time.
• Simply costs much money.
Consequences of the limitations
• Noise in the projections.
• Limited amount of projections.
• Leading to uncertainty of the data.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Problem with reconstruction
This was the ideal case, which is not so common.
Taking many projection of good quality has high costs.
• High radiation dosage.
• High acquisition time.
• Simply costs much money.
Consequences of the limitations
• Noise in the projections.
• Limited amount of projections.
• Leading to uncertainty of the data.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Problem with reconstruction
This was the ideal case, which is not so common.
Taking many projection of good quality has high costs.
• High radiation dosage.
• High acquisition time.
• Simply costs much money.
Consequences of the limitations
• Noise in the projections.
• Limited amount of projections.
• Leading to uncertainty of the data.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Problem with reconstruction
This was the ideal case, which is not so common.
Taking many projection of good quality has high costs.
• High radiation dosage.
• High acquisition time.
• Simply costs much money.
Consequences of the limitations
• Noise in the projections.
• Limited amount of projections.
• Leading to uncertainty of the data.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in the projections.
Basic background:
• We emit a given number ofX-ray photons.
• Some of them are absorbed bythe material.
In formulation:
• I0 emitted number of photons.
• If measured number ofphotons.
• If = I0e−
∫f (x)dx
Projection:
• ∫f (x)dx = − If
I0
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in the projections.
Basic background:
• We emit a given number ofX-ray photons.
• Some of them are absorbed bythe material.
In formulation:
• I0 emitted number of photons.
• If measured number ofphotons.
• If = I0e−
∫f (x)dx
Projection:
• ∫f (x)dx = − If
I0
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in the projections.
Basic background:
• We emit a given number ofX-ray photons.
• Some of them are absorbed bythe material.
In formulation:
• I0 emitted number of photons.
• If measured number ofphotons.
• If = I0e−
∫f (x)dx
Projection:
• ∫f (x)dx = − If
I0
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in the projections.
Source of the noise:If follows Poisson distribution:
Causing:
• Less photons lead to morenoise.
• More photons mean lessnoise.
• But also moreradiation.
• i.e.: more harm to thepatient, more cost, etc.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in the projections.
Source of the noise:If follows Poisson distribution:
Causing:
• Less photons lead to morenoise.
• More photons mean lessnoise.
• But also moreradiation.
• i.e.: more harm to thepatient, more cost, etc.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in the projections.
Source of the noise:If follows Poisson distribution:
Causing:
• Less photons lead to morenoise.
• More photons mean lessnoise.
• But also moreradiation.
• i.e.: more harm to thepatient, more cost, etc.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in the projections.
Source of the noise:If follows Poisson distribution:
Causing:
• Less photons lead to morenoise.
• More photons mean lessnoise.
• But also moreradiation.
• i.e.: more harm to thepatient, more cost, etc.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in the projections.
Source of the noise:If follows Poisson distribution:
Causing:
• Less photons lead to morenoise.
• More photons mean lessnoise.
• But also moreradiation.
• i.e.: more harm to thepatient, more cost, etc.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in the projections.
Source of the noise:If follows Poisson distribution:
Causing:
• Less photons lead to morenoise.
• More photons mean lessnoise.
• But also moreradiation.
• i.e.: more harm to thepatient, more cost, etc.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in practice
100000 photons 1000 photons 100 photons/ pixel / pixel / pixel
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in practice
100000 photons
1000 photons 100 photons
/ pixel
/ pixel / pixel
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in practice
100000 photons 1000 photons
100 photons
/ pixel / pixel
/ pixel
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in practice
100000 photons 1000 photons 100 photons/ pixel / pixel / pixel
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in practice
100000 photons 1000 photons 100 photons/ pixel / pixel / pixel
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in practice
100000 photons
1000 photons 100 photons
/ pixel
/ pixel / pixel
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in practice
100000 photons 1000 photons
100 photons
/ pixel / pixel
/ pixel
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise in practice
100000 photons 1000 photons 100 photons/ pixel / pixel / pixel
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Handling noise
Easy ways to handle noise
• Use high photon counts.
• Increases radiation dosage and cost.• Makes better measurements.
• Use many projections.
• Might also increases radiation dosage and cost,• Projections average out each other, and suppress noise.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Handling noise
Easy ways to handle noise
• Use high photon counts.
• Increases radiation dosage and cost.• Makes better measurements.
• Use many projections.
• Might also increases radiation dosage and cost,• Projections average out each other, and suppress noise.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Handling noise
Easy ways to handle noise
• Use high photon counts.• Increases radiation dosage and cost.• Makes better measurements.
• Use many projections.
• Might also increases radiation dosage and cost,• Projections average out each other, and suppress noise.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Handling noise
Easy ways to handle noise
• Use high photon counts.• Increases radiation dosage and cost.• Makes better measurements.
• Use many projections.• Might also increases radiation dosage and cost,• Projections average out each other, and suppress noise.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise and many projections
45 projs., 45 projs., 180 projs.,100000 photons 10000 photons 10000 photons
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Handling noise
Easy ways to handle noise
• Use high photon counts.• Increases radiation dosage and cost.• Makes better measurements.
• Use many projections.• Might also increases radiation dosage and cost,• Projections average out each other, and suppress noise.
Algorithmic ways to handle noise
• Use more advanced reconstruction techniques.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Handling noise
Easy ways to handle noise
• Use high photon counts.• Increases radiation dosage and cost.• Makes better measurements.
• Use many projections.• Might also increases radiation dosage and cost,• Projections average out each other, and suppress noise.
Algorithmic ways to handle noise
• Use more advanced reconstruction techniques.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Handling noise
Easy ways to handle noise
• Use high photon counts.• Increases radiation dosage and cost.• Makes better measurements.
• Use many projections.• Might also increases radiation dosage and cost,• Projections average out each other, and suppress noise.
Algorithmic ways to handle noise
• Use more advanced reconstruction techniques.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction from fewprojections
Sometimes we only have only few projections
Possible causes:
• We want to reduce radiation dosage,
• One projection needs long exposure time (e.g., whenimaging dense objects),
• Exposure damages the object (e.g., crystallography.)
New problems arise
The data is sparse:
• We have less measurements then pixels.
• There are many possible reconstruction, all possibleaccording to projections.
• Algorithms start to ’guess’ and find the wrong result.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction from fewprojections
Sometimes we only have only few projections
Possible causes:
• We want to reduce radiation dosage,
• One projection needs long exposure time (e.g., whenimaging dense objects),
• Exposure damages the object (e.g., crystallography.)
New problems arise
The data is sparse:
• We have less measurements then pixels.
• There are many possible reconstruction, all possibleaccording to projections.
• Algorithms start to ’guess’ and find the wrong result.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction from fewprojections
Sometimes we only have only few projections
Possible causes:
• We want to reduce radiation dosage,
• One projection needs long exposure time (e.g., whenimaging dense objects),
• Exposure damages the object (e.g., crystallography.)
New problems arise
The data is sparse:
• We have less measurements then pixels.
• There are many possible reconstruction, all possibleaccording to projections.
• Algorithms start to ’guess’ and find the wrong result.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction from fewprojections
Sometimes we only have only few projections
Possible causes:
• We want to reduce radiation dosage,
• One projection needs long exposure time (e.g., whenimaging dense objects),
• Exposure damages the object (e.g., crystallography.)
New problems arise
The data is sparse:
• We have less measurements then pixels.
• There are many possible reconstruction, all possibleaccording to projections.
• Algorithms start to ’guess’ and find the wrong result.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction from fewprojections
Sometimes we only have only few projections
Possible causes:
• We want to reduce radiation dosage,
• One projection needs long exposure time (e.g., whenimaging dense objects),
• Exposure damages the object (e.g., crystallography.)
New problems arise
The data is sparse:
• We have less measurements then pixels.
• There are many possible reconstruction, all possibleaccording to projections.
• Algorithms start to ’guess’ and find the wrong result.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction from fewprojections
Sometimes we only have only few projections
Possible causes:
• We want to reduce radiation dosage,
• One projection needs long exposure time (e.g., whenimaging dense objects),
• Exposure damages the object (e.g., crystallography.)
New problems arise
The data is sparse:
• We have less measurements then pixels.
• There are many possible reconstruction, all possibleaccording to projections.
• Algorithms start to ’guess’ and find the wrong result.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction from fewprojections
Sometimes we only have only few projections
Possible causes:
• We want to reduce radiation dosage,
• One projection needs long exposure time (e.g., whenimaging dense objects),
• Exposure damages the object (e.g., crystallography.)
New problems arise
The data is sparse:
• We have less measurements then pixels.
• There are many possible reconstruction, all possibleaccording to projections.
• Algorithms start to ’guess’ and find the wrong result.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction from fewprojections
Sometimes we only have only few projections
Possible causes:
• We want to reduce radiation dosage,
• One projection needs long exposure time (e.g., whenimaging dense objects),
• Exposure damages the object (e.g., crystallography.)
New problems arise
The data is sparse:
• We have less measurements then pixels.
• There are many possible reconstruction, all possibleaccording to projections.
• Algorithms start to ’guess’ and find the wrong result.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Low projection Count in practice
180 projs., 30 projs., 6 projs.,FBP FBP FBP
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Low projection Count in practice
180 projs.,
30 projs., 6 projs.,
FBP
FBP FBP
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Low projection Count in practice
180 projs., 30 projs.,
6 projs.,
FBP FBP
FBP
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Low projection Count in practice
180 projs., 30 projs., 6 projs.,FBP FBP FBP
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Handling effects of low projectioncount
Easy ways:
• Take more projections.
• Not always possible.• should be considered...
• Take more projections with lower photon counts.
• Sometimes possible (e.g.: half the exposure time perprojection, and double projection count),
• Leads to more but more noisy projections.
Algorithmic ways to handle noise
• Use more advanced reconstruction techniques.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Handling effects of low projectioncount
Easy ways:
• Take more projections.
• Not always possible.• should be considered...
• Take more projections with lower photon counts.
• Sometimes possible (e.g.: half the exposure time perprojection, and double projection count),
• Leads to more but more noisy projections.
Algorithmic ways to handle noise
• Use more advanced reconstruction techniques.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Handling effects of low projectioncount
Easy ways:
• Take more projections.• Not always possible.• should be considered...
• Take more projections with lower photon counts.
• Sometimes possible (e.g.: half the exposure time perprojection, and double projection count),
• Leads to more but more noisy projections.
Algorithmic ways to handle noise
• Use more advanced reconstruction techniques.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Handling effects of low projectioncount
Easy ways:
• Take more projections.• Not always possible.• should be considered...
• Take more projections with lower photon counts.• Sometimes possible (e.g.: half the exposure time per
projection, and double projection count),• Leads to more but more noisy projections.
Algorithmic ways to handle noise
• Use more advanced reconstruction techniques.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Handling effects of low projectioncount
Easy ways:
• Take more projections.• Not always possible.• should be considered...
• Take more projections with lower photon counts.• Sometimes possible (e.g.: half the exposure time per
projection, and double projection count),• Leads to more but more noisy projections.
Algorithmic ways to handle noise
• Use more advanced reconstruction techniques.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction algorithms
Common basic techniques
• Filtered Back-Projection
• Fast method based on mathematical concept. (Filteringand back-projection)
• Needs many projections for good results.
Continuous algebraic reconstruction
• ART, SART, CGLS, etc.
• Iterative equation system solvers,• Slightly better then FBP, but need more time (many
filtering + back-projection cycles).
Discrete algebraic reconstruction
• DART, Energy minimization techniques, etc.
• Iterative equation system solvers, with priors,• Good results, but huge time requirement.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction algorithms
Common basic techniques
• Filtered Back-Projection
• Fast method based on mathematical concept. (Filteringand back-projection)
• Needs many projections for good results.
Continuous algebraic reconstruction
• ART, SART, CGLS, etc.
• Iterative equation system solvers,• Slightly better then FBP, but need more time (many
filtering + back-projection cycles).
Discrete algebraic reconstruction
• DART, Energy minimization techniques, etc.
• Iterative equation system solvers, with priors,• Good results, but huge time requirement.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction algorithms
Common basic techniques
• Filtered Back-Projection
• Fast method based on mathematical concept. (Filteringand back-projection)
• Needs many projections for good results.
Continuous algebraic reconstruction
• ART, SART, CGLS, etc.
• Iterative equation system solvers,• Slightly better then FBP, but need more time (many
filtering + back-projection cycles).
Discrete algebraic reconstruction
• DART, Energy minimization techniques, etc.
• Iterative equation system solvers, with priors,• Good results, but huge time requirement.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction algorithms
Common basic techniques
• Filtered Back-Projection• Fast method based on mathematical concept. (Filtering
and back-projection)• Needs many projections for good results.
Continuous algebraic reconstruction
• ART, SART, CGLS, etc.
• Iterative equation system solvers,• Slightly better then FBP, but need more time (many
filtering + back-projection cycles).
Discrete algebraic reconstruction
• DART, Energy minimization techniques, etc.
• Iterative equation system solvers, with priors,• Good results, but huge time requirement.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction algorithms
Common basic techniques
• Filtered Back-Projection• Fast method based on mathematical concept. (Filtering
and back-projection)• Needs many projections for good results.
Continuous algebraic reconstruction
• ART, SART, CGLS, etc.
• Iterative equation system solvers,• Slightly better then FBP, but need more time (many
filtering + back-projection cycles).
Discrete algebraic reconstruction
• DART, Energy minimization techniques, etc.
• Iterative equation system solvers, with priors,• Good results, but huge time requirement.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction algorithms
Common basic techniques
• Filtered Back-Projection• Fast method based on mathematical concept. (Filtering
and back-projection)• Needs many projections for good results.
Continuous algebraic reconstruction
• ART, SART, CGLS, etc.
• Iterative equation system solvers,• Slightly better then FBP, but need more time (many
filtering + back-projection cycles).
Discrete algebraic reconstruction
• DART, Energy minimization techniques, etc.
• Iterative equation system solvers, with priors,• Good results, but huge time requirement.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction algorithms
Common basic techniques
• Filtered Back-Projection• Fast method based on mathematical concept. (Filtering
and back-projection)• Needs many projections for good results.
Continuous algebraic reconstruction
• ART, SART, CGLS, etc.• Iterative equation system solvers,
• Slightly better then FBP, but need more time (manyfiltering + back-projection cycles).
Discrete algebraic reconstruction
• DART, Energy minimization techniques, etc.
• Iterative equation system solvers, with priors,• Good results, but huge time requirement.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction algorithms
Common basic techniques
• Filtered Back-Projection• Fast method based on mathematical concept. (Filtering
and back-projection)• Needs many projections for good results.
Continuous algebraic reconstruction
• ART, SART, CGLS, etc.• Iterative equation system solvers,• Slightly better then FBP, but need more time (many
filtering + back-projection cycles).
Discrete algebraic reconstruction
• DART, Energy minimization techniques, etc.
• Iterative equation system solvers, with priors,• Good results, but huge time requirement.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction algorithms
Common basic techniques
• Filtered Back-Projection• Fast method based on mathematical concept. (Filtering
and back-projection)• Needs many projections for good results.
Continuous algebraic reconstruction
• ART, SART, CGLS, etc.• Iterative equation system solvers,• Slightly better then FBP, but need more time (many
filtering + back-projection cycles).
Discrete algebraic reconstruction
• DART, Energy minimization techniques, etc.
• Iterative equation system solvers, with priors,• Good results, but huge time requirement.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction algorithms
Common basic techniques
• Filtered Back-Projection• Fast method based on mathematical concept. (Filtering
and back-projection)• Needs many projections for good results.
Continuous algebraic reconstruction
• ART, SART, CGLS, etc.• Iterative equation system solvers,• Slightly better then FBP, but need more time (many
filtering + back-projection cycles).
Discrete algebraic reconstruction
• DART, Energy minimization techniques, etc.
• Iterative equation system solvers, with priors,• Good results, but huge time requirement.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction algorithms
Common basic techniques
• Filtered Back-Projection• Fast method based on mathematical concept. (Filtering
and back-projection)• Needs many projections for good results.
Continuous algebraic reconstruction
• ART, SART, CGLS, etc.• Iterative equation system solvers,• Slightly better then FBP, but need more time (many
filtering + back-projection cycles).
Discrete algebraic reconstruction
• DART, Energy minimization techniques, etc.• Iterative equation system solvers, with priors,
• Good results, but huge time requirement.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Reconstruction algorithms
Common basic techniques
• Filtered Back-Projection• Fast method based on mathematical concept. (Filtering
and back-projection)• Needs many projections for good results.
Continuous algebraic reconstruction
• ART, SART, CGLS, etc.• Iterative equation system solvers,• Slightly better then FBP, but need more time (many
filtering + back-projection cycles).
Discrete algebraic reconstruction
• DART, Energy minimization techniques, etc.• Iterative equation system solvers, with priors,• Good results, but huge time requirement.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Continuous algebraicreconstruction algorithms
Iterative approximations of the solution
• Usually more accurate then FBP, because of the iterativeimprovement of the result.
• Can incorporate basic prior information
• L1, L2 norm.• bounds on intensities.
• Has higher computational time.
• Each iteration takes as much time as FBP itself.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Continuous algebraicreconstruction algorithms
Iterative approximations of the solution
• Usually more accurate then FBP, because of the iterativeimprovement of the result.
• Can incorporate basic prior information
• L1, L2 norm.• bounds on intensities.
• Has higher computational time.
• Each iteration takes as much time as FBP itself.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Continuous algebraicreconstruction algorithms
Iterative approximations of the solution
• Usually more accurate then FBP, because of the iterativeimprovement of the result.
• Can incorporate basic prior information
• L1, L2 norm.• bounds on intensities.
• Has higher computational time.
• Each iteration takes as much time as FBP itself.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Continuous algebraicreconstruction algorithms
Iterative approximations of the solution
• Usually more accurate then FBP, because of the iterativeimprovement of the result.
• Can incorporate basic prior information• L1, L2 norm.• bounds on intensities.
• Has higher computational time.
• Each iteration takes as much time as FBP itself.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Continuous algebraicreconstruction algorithms
Iterative approximations of the solution
• Usually more accurate then FBP, because of the iterativeimprovement of the result.
• Can incorporate basic prior information• L1, L2 norm.• bounds on intensities.
• Has higher computational time.• Each iteration takes as much time as FBP itself.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Formulation of the reconstructionproblem
• With this the reconstruction problem can be reformulated as asystem of equations Ax = b, where:
• b, is the vector of m projection values,• x, represents the vector of the image pixel values,• A, describes the connection between the image pixels, and
the projection values, with all aij giving the length linesegment of the i-th projection line in the j pixel.
x1 x2 x3 x4
x5 x6 x7 x8
x9 x10 x11 x12
x13 x14 x15 x16 Source
Detector
xjbi
bi+1
ai,j
ai+1,j
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Formulation of the reconstructionproblem
• With this the reconstruction problem can be reformulated as asystem of equations Ax = b, where:
• b, is the vector of m projection values,• x, represents the vector of the image pixel values,• A, describes the connection between the image pixels, and
the projection values, with all aij giving the length linesegment of the i-th projection line in the j pixel.
x1 x2 x3 x4
x5 x6 x7 x8
x9 x10 x11 x12
x13 x14 x15 x16 Source
Detector
xjbi
bi+1
ai,j
ai+1,j
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Algebraic reconstruction withsimple prior
Algebraic reconstruction with lower and upper bounds
• Pixel values can be in a well defined range (which can bedetermined by previous measurements)
Solve
Ax = b
Subject to
xi ∈ [0, 1]
10
1
x1
x2 Convex set ofsolutions
Ax = b
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Algebraic reconstruction withsimple prior
Algebraic reconstruction with lower and upper bounds
• Pixel values can be in a well defined range (which can bedetermined by previous measurements)
Solve
Ax = b
Subject to
xi ∈ [0, 1]
10
1
x1
x2 Convex set ofsolutions
Ax = b
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Algebraic reconstruction withsimple prior
Algebraic reconstruction with lower and upper bounds
• Pixel values can be in a well defined range (which can bedetermined by previous measurements)
Solve
Ax = b
Subject to
xi ∈ [0, 1]
10
1
x1
x2 Convex set ofsolutions
Ax = b
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Results of Iterative algorithms
180 projs., 30 projs., 30 projs.,FBP FBP SIRT
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Results of Iterative algorithms
180 projs.,
30 projs., 30 projs.,
FBP
FBP SIRT
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Results of Iterative algorithms
180 projs., 30 projs.,
30 projs.,
FBP FBP
SIRT
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Results of Iterative algorithms
180 projs., 30 projs., 30 projs.,FBP FBP SIRT
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Discrete algebraic reconstruction
E.g., binary tomography. The pixel values can be either 0 or 1.
Solve
Ax = b
Subject to
xi ∈ {0, 1}
10
1
x1
x2
Ax = b
Binary values
Can also be formulated with energy function.
E =1
2‖Ax + b‖2
2 +α
2
n∑i=1
∑j∈N4i
(xi − xj)2 +
µ
2〈x, 1− x〉
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Discrete algebraic reconstruction
E.g., binary tomography. The pixel values can be either 0 or 1.
Solve
Ax = b
Subject to
xi ∈ {0, 1}
10
1
x1
x2
Ax = b
Binary values
Can also be formulated with energy function.
E =1
2‖Ax + b‖2
2 +α
2
n∑i=1
∑j∈N4i
(xi − xj)2 +
µ
2〈x, 1− x〉
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Discrete algebraic reconstruction
E.g., binary tomography. The pixel values can be either 0 or 1.
Solve
Ax = b
Subject to
xi ∈ {0, 1}
10
1
x1
x2
Ax = b
Binary values
Can also be formulated with energy function.
E =1
2‖Ax + b‖2
2 +α
2
n∑i=1
∑j∈N4i
(xi − xj)2 +
µ
2〈x, 1− x〉
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Discrete algebraic reconstruction
E.g., binary tomography. The pixel values can be either 0 or 1.
Solve
Ax = b
Subject to
xi ∈ {0, 1}
10
1
x1
x2
Ax = b
Binary values
Can also be formulated with energy function.
E =1
2‖Ax + b‖2
2 +α
2
n∑i=1
∑j∈N4i
(xi − xj)2 +
µ
2〈x, 1− x〉
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Discrete algebraic reconstruction
E.g., binary tomography. The pixel values can be either 0 or 1.
Solve
Ax = b
Subject to
xi ∈ {0, 1}
10
1
x1
x2
Ax = b
Binary values
Can also be formulated with energy function.
E =1
2‖Ax + b‖2
2 +α
2
n∑i=1
∑j∈N4i
(xi − xj)2 +
µ
2〈x, 1− x〉
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Results of discrete algorithms
10 projs., 10 projs., 10 projs.,FBP SIRT Discrete
0.001725 sec. 0.408 sec. 19.878 sec.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Results of discrete algorithms
10 projs.,
10 projs., 10 projs.,
FBP
SIRT Discrete0.001725 sec. 0.408 sec. 19.878 sec.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Results of discrete algorithms
10 projs., 10 projs.,
10 projs.,
FBP SIRT
Discrete0.001725 sec. 0.408 sec. 19.878 sec.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Results of discrete algorithms
10 projs., 10 projs., 10 projs.,FBP SIRT Discrete
0.001725 sec. 0.408 sec. 19.878 sec.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Results of discrete algorithms
10 projs., 10 projs., 10 projs.,FBP SIRT Discrete
0.001725 sec.
0.408 sec. 19.878 sec.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Results of discrete algorithms
10 projs., 10 projs., 10 projs.,FBP SIRT Discrete
0.001725 sec. 0.408 sec.
19.878 sec.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Results of discrete algorithms
10 projs., 10 projs., 10 projs.,FBP SIRT Discrete
0.001725 sec. 0.408 sec. 19.878 sec.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
What about other imaging likeMRI?
Magnetic Resonance imaging
• Nuclei in our atoms are made of protons and electrons.
• Each particle has two attributes• Spin,• optionally charge.
• If the munber of spins is even, then they cancell eachotherout, but atoms with an odd number of spins has aaccumuted spin.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
What about other imaging likeMRI?
Magnetic Resonance imaging
• Nuclei in our atoms are made of protons and electrons.
• Each particle has two attributes• Spin,• optionally charge.
• If the munber of spins is even, then they cancell eachotherout, but atoms with an odd number of spins has aaccumuted spin.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Magnetic Resonance Imaging
In a strong magnetic field, spin of the atoms get aligned withthe direction of the field.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Magnetic Resonance Imaging
• Periodic radio signals can change
direction of the nuclei.
• Excitation frequencycorresponds to the atomand magnetic field energy.
• After stopping the radio signalthe nuclei start to return to theiroriginal direction.
• In the process they emitelectromagnetic signals.
• Measuring the attenuation of thesignal gives information on theatoms along a plane in space.
• Having data on enough planesthe task is similar to transmissiontomography.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Magnetic Resonance Imaging
• Periodic radio signals can change
direction of the nuclei.
• Excitation frequencycorresponds to the atomand magnetic field energy.
• After stopping the radio signalthe nuclei start to return to theiroriginal direction.
• In the process they emitelectromagnetic signals.
• Measuring the attenuation of thesignal gives information on theatoms along a plane in space.
• Having data on enough planesthe task is similar to transmissiontomography.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Magnetic Resonance Imaging
• Periodic radio signals can change
direction of the nuclei.
• Excitation frequencycorresponds to the atomand magnetic field energy.
• After stopping the radio signalthe nuclei start to return to theiroriginal direction.
• In the process they emitelectromagnetic signals.
• Measuring the attenuation of thesignal gives information on theatoms along a plane in space.
• Having data on enough planesthe task is similar to transmissiontomography.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Magnetic Resonance Imaging
• Periodic radio signals can change
direction of the nuclei.
• Excitation frequencycorresponds to the atomand magnetic field energy.
• After stopping the radio signalthe nuclei start to return to theiroriginal direction.
• In the process they emitelectromagnetic signals.
• Measuring the attenuation of thesignal gives information on theatoms along a plane in space.
• Having data on enough planesthe task is similar to transmissiontomography.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Magnetic Resonance Imaging
• Periodic radio signals can change
direction of the nuclei.
• Excitation frequencycorresponds to the atomand magnetic field energy.
• After stopping the radio signalthe nuclei start to return to theiroriginal direction.
• In the process they emitelectromagnetic signals.
• Measuring the attenuation of thesignal gives information on theatoms along a plane in space.
• Having data on enough planesthe task is similar to transmissiontomography.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Magnetic Resonance Imaging
• Periodic radio signals can change
direction of the nuclei.
• Excitation frequencycorresponds to the atomand magnetic field energy.
• After stopping the radio signalthe nuclei start to return to theiroriginal direction.
• In the process they emitelectromagnetic signals.
• Measuring the attenuation of thesignal gives information on theatoms along a plane in space.
• Having data on enough planesthe task is similar to transmissiontomography.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Magnetic Resonance Imaging
• Periodic radio signals can change
direction of the nuclei.
• Excitation frequencycorresponds to the atomand magnetic field energy.
• After stopping the radio signalthe nuclei start to return to theiroriginal direction.
• In the process they emitelectromagnetic signals.
• Measuring the attenuation of thesignal gives information on theatoms along a plane in space.
• Having data on enough planesthe task is similar to transmissiontomography.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise and lack of data in MRI
Cost of imaging is time
• In MRI imaging every one measurement has distortions(noise).
• It has to be repeated many times.
• The measurement has to be repeated on many planes.
• Each measurement takes time, while we wait for the nucleito get back in order.
• Measurement can be highly time-consuming.
• High resolution imaging can take up to half an our or more.
Problems and possibilities
• Less measurements with more noise?
• More imaging time?
• Advanced algorithms?
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise and lack of data in MRI
Cost of imaging is time
• In MRI imaging every one measurement has distortions(noise).
• It has to be repeated many times.
• The measurement has to be repeated on many planes.
• Each measurement takes time, while we wait for the nucleito get back in order.
• Measurement can be highly time-consuming.
• High resolution imaging can take up to half an our or more.
Problems and possibilities
• Less measurements with more noise?
• More imaging time?
• Advanced algorithms?
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise and lack of data in MRI
Cost of imaging is time
• In MRI imaging every one measurement has distortions(noise).
• It has to be repeated many times.
• The measurement has to be repeated on many planes.
• Each measurement takes time, while we wait for the nucleito get back in order.
• Measurement can be highly time-consuming.
• High resolution imaging can take up to half an our or more.
Problems and possibilities
• Less measurements with more noise?
• More imaging time?
• Advanced algorithms?
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise and lack of data in MRI
Cost of imaging is time
• In MRI imaging every one measurement has distortions(noise).
• It has to be repeated many times.
• The measurement has to be repeated on many planes.
• Each measurement takes time, while we wait for the nucleito get back in order.
• Measurement can be highly time-consuming.
• High resolution imaging can take up to half an our or more.
Problems and possibilities
• Less measurements with more noise?
• More imaging time?
• Advanced algorithms?
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise and lack of data in MRI
Cost of imaging is time
• In MRI imaging every one measurement has distortions(noise).
• It has to be repeated many times.
• The measurement has to be repeated on many planes.
• Each measurement takes time, while we wait for the nucleito get back in order.
• Measurement can be highly time-consuming.
• High resolution imaging can take up to half an our or more.
Problems and possibilities
• Less measurements with more noise?
• More imaging time?
• Advanced algorithms?
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise and lack of data in MRI
Cost of imaging is time
• In MRI imaging every one measurement has distortions(noise).
• It has to be repeated many times.
• The measurement has to be repeated on many planes.
• Each measurement takes time, while we wait for the nucleito get back in order.
• Measurement can be highly time-consuming.• High resolution imaging can take up to half an our or more.
Problems and possibilities
• Less measurements with more noise?
• More imaging time?
• Advanced algorithms?
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise and lack of data in MRI
Cost of imaging is time
• In MRI imaging every one measurement has distortions(noise).
• It has to be repeated many times.
• The measurement has to be repeated on many planes.
• Each measurement takes time, while we wait for the nucleito get back in order.
• Measurement can be highly time-consuming.• High resolution imaging can take up to half an our or more.
Problems and possibilities
• Less measurements with more noise?
• More imaging time?
• Advanced algorithms?
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise and lack of data in MRI
Cost of imaging is time
• In MRI imaging every one measurement has distortions(noise).
• It has to be repeated many times.
• The measurement has to be repeated on many planes.
• Each measurement takes time, while we wait for the nucleito get back in order.
• Measurement can be highly time-consuming.• High resolution imaging can take up to half an our or more.
Problems and possibilities
• Less measurements with more noise?
• More imaging time?
• Advanced algorithms?
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise and lack of data in MRI
Cost of imaging is time
• In MRI imaging every one measurement has distortions(noise).
• It has to be repeated many times.
• The measurement has to be repeated on many planes.
• Each measurement takes time, while we wait for the nucleito get back in order.
• Measurement can be highly time-consuming.• High resolution imaging can take up to half an our or more.
Problems and possibilities
• Less measurements with more noise?
• More imaging time?
• Advanced algorithms?
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Noise and lack of data in MRI
Cost of imaging is time
• In MRI imaging every one measurement has distortions(noise).
• It has to be repeated many times.
• The measurement has to be repeated on many planes.
• Each measurement takes time, while we wait for the nucleito get back in order.
• Measurement can be highly time-consuming.• High resolution imaging can take up to half an our or more.
Problems and possibilities
• Less measurements with more noise?
• More imaging time?
• Advanced algorithms?
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Summary
There are many ways to take accurate images of the interior ofobjects.
• The simple way is to take many data (measurement) ofgood quality.
• If the data quality is not good it can be balanced by hugeamount.
• If the amount of data is not sufficient?
• It might be handled by advanced methods.• These methods use extra resources for improved imaging.
• Prior knowledge on the data (takes time to find out goodpriors.)
• Extra computational time to incorporate prior int theimaging.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Summary
There are many ways to take accurate images of the interior ofobjects.
• The simple way is to take many data (measurement) ofgood quality.
• If the data quality is not good it can be balanced by hugeamount.
• If the amount of data is not sufficient?
• It might be handled by advanced methods.• These methods use extra resources for improved imaging.
• Prior knowledge on the data (takes time to find out goodpriors.)
• Extra computational time to incorporate prior int theimaging.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Summary
There are many ways to take accurate images of the interior ofobjects.
• The simple way is to take many data (measurement) ofgood quality.
• If the data quality is not good it can be balanced by hugeamount.
• If the amount of data is not sufficient?
• It might be handled by advanced methods.• These methods use extra resources for improved imaging.
• Prior knowledge on the data (takes time to find out goodpriors.)
• Extra computational time to incorporate prior int theimaging.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Summary
There are many ways to take accurate images of the interior ofobjects.
• The simple way is to take many data (measurement) ofgood quality.
• If the data quality is not good it can be balanced by hugeamount.
• If the amount of data is not sufficient?
• It might be handled by advanced methods.• These methods use extra resources for improved imaging.
• Prior knowledge on the data (takes time to find out goodpriors.)
• Extra computational time to incorporate prior int theimaging.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Summary
There are many ways to take accurate images of the interior ofobjects.
• The simple way is to take many data (measurement) ofgood quality.
• If the data quality is not good it can be balanced by hugeamount.
• If the amount of data is not sufficient?• It might be handled by advanced methods.
• These methods use extra resources for improved imaging.
• Prior knowledge on the data (takes time to find out goodpriors.)
• Extra computational time to incorporate prior int theimaging.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Summary
There are many ways to take accurate images of the interior ofobjects.
• The simple way is to take many data (measurement) ofgood quality.
• If the data quality is not good it can be balanced by hugeamount.
• If the amount of data is not sufficient?• It might be handled by advanced methods.• These methods use extra resources for improved imaging.
• Prior knowledge on the data (takes time to find out goodpriors.)
• Extra computational time to incorporate prior int theimaging.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Summary
There are many ways to take accurate images of the interior ofobjects.
• The simple way is to take many data (measurement) ofgood quality.
• If the data quality is not good it can be balanced by hugeamount.
• If the amount of data is not sufficient?• It might be handled by advanced methods.• These methods use extra resources for improved imaging.
• Prior knowledge on the data (takes time to find out goodpriors.)
• Extra computational time to incorporate prior int theimaging.
Uncertainty ofNon-
DestructiveInteriorImaging
Techniques
Laszlo Varga
Introduction:ImagingTechniques
TransmissionTomography
Problemformulation
Uncertainties intransmissiontomography
Noise
Lowinformationcontent
Advancedreconstructiontechniques
Datauncertainty inMRI
Summary
There are many ways to take accurate images of the interior ofobjects.
• The simple way is to take many data (measurement) ofgood quality.
• If the data quality is not good it can be balanced by hugeamount.
• If the amount of data is not sufficient?• It might be handled by advanced methods.• These methods use extra resources for improved imaging.
• Prior knowledge on the data (takes time to find out goodpriors.)
• Extra computational time to incorporate prior int theimaging.