A Survey of Current Acquisition & Analysis Techniques for
Myocardial Perfusion Imaging Using Philips Gamma Cameras
Joe O’Brien & Bill Thomson, City Hospital, Birmingham
Cariss Bird, Priory Hospital, Birmingham
&
Introduction• Aware of some variation amongst Philips users in
acquiring and analysing Myocardial Perfusion Imaging (MPI) studies.
• Decided to provide a survey for Philips NMUG Meeting.
• The survey would be beneficial:– Forms a basis of discussion at UG Meeting.– Allows users to compare their technique with
others.
Survey & Presentation
Marconi & Picker Systems
Joe O’Brien
ADAC Systems
Cariss Bird
Due to work commitments and time constraints, just
the Marconi & Picker users have been surveyed.
The Survey
• 30 customers on Philips NM customer list
• 12 customers do not perform MPIs
• 1 customer did not participate
• So 17 customers surveyed
• Completed surveys available
• Contacted via telephone for anonymous survey
The Survey• Basic Questions
• Radio-pharmaceutical
e.g. how many patients per year?
e.g. type of RP, activity per test, delay time?
• Gamma Camera e.g. which camera and collimator do you use?
• Acquisition
• Reconstruction
e.g. matrix size & zoom (pixel size), orbit setup, gated or non-gated?
e.g. FBP or iterative reconstruction, Pre-filter or 3D Post filter ?
Basic Questions
MPI Patients per Annum per Camera
0 200 400 600 800 1000 1200 1400 1600
1
3
5
7
9
11
13
15
17
Cu
sto
mer
Number of Patients
Radiopharmaceutical• Most commonly used:
MIBI(5)
Tetrofosmin(12)
Radiopharmaceutical
1 Day1000MBq
(2)
2 Day400MBq
(15)
• Protocol:
Radiopharmaceutical• Imaging Delay Time:
0 20 40 60 80 100 120
1
5
9
13
17
Cus
tom
er
Delay Time in Minutes
MIBI
Tetro
Cameras Included in Survey
• Dual headed AXIS most common
• Exclude others from presentation
Axis
Prism 2000XP
Prism 3000XP
Prism 1000XPIrix
(11)
(4)
(2)
(1)
Acquisition Settings Used By All AXIS Users
• Orbit settings:
– Non-Circular
– Head Orientation at 102°
– 102° of rotation per head
– 34 projections per head
• Acquisition based on TIME per step
• Factory set energy window
Variable Acquisition Settings
• Orbit setting
– Step & Shoot - 3 Continuous - 8
• Gating
– Gated - 5 Non-Gated - 6
• BEACON
– Used - 3 Not Used - 8
Variable Acquisition Settings
• Time per step
010203040506070
1 2 3 4 5 6 7 8 9 10 11
Customer
Tim
e (S
eco
nd
s) STRESS
REST
Variable Acquisition Settings
• Collimator
LEGAP
(6)
LEHR
(5)
Variable Acquisition Settings
• Matrix & Zoom (i.e Pixel Size)
No of Users Matrix Zoom Pixel Size
4 128 by 128 1.000 4.67
5 64 by 64 1.600 5.84
1 64 by 64 1.488 6.28
1 Not sure
Reconstruction Settings Used By All AXIS Users
• Routinely Check for Patient Motion
• No Pre-filtering of data
• All use 3D Post-filter
Variable Reconstruction Settings
• Reconstruction Method
Iterative(3)
Don’t Know(1)
FBP(7)
Variable Reconstruction Settings
• Diameter
• Effectively zooms data and alters pixel size. Left as Default
(8)
Don’t Know(2)
Varied between patients
(1)
Variable Reconstruction Settings
• Filter– All used ‘Low Pass’ but with variable settings:
Variable Reconstruction Settings
• Gated Analysis Programs
QGS(4)
Emory(1)
Conclusions• Survey of Philips NM Users performing MPI.
• Majority using AXIS system.
• Users have some similar methods of acquisition
and analysis.
• But overall there are significant differences e.g.
1/2 use LEHR, the other 1/2 use LEGAP
• Worthy of discussion at UGM!
Effect of Collimator
• Local standard protocol for MPI uses LEGAP collimator.
• We considered the effect on lesion detectability using a
LEHR collimator instead.
• Scanned a torso phantom fitted with a cardiac insert
• Installed a large 100% and small 50% defect.
• Filled with 8MBq Tc-99m
Effect of Collimator• Short Axis Images
• Qualitatively, there is no discernable difference in lesion detectability
HR
GP
Effect of Collimator• HLA Images
• Qualitatively, no discernable difference in lesion detectability.
• But up to 40% more counts.
HR
GP