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David M Isaacs, DORotating Resident at
William Beaumont Hospital Department of Nuclear Medicine
Cardiac Anatomy utilizing CT Angiography
ObjectivesExamine the need for Coronary Anatomy
Imaging using CT Angiography (CTA)Explore the basic Technique and dose of
Coronary CT Angiography (CCTA)Examine the different reconstruction
algorithmsDetail the Coronary Anatomy utilizing CCTAExamine Cardiac CTA for imaging veins and
other heart structuresBriefly review recently published data
regarding clinical applications of CCTA
BackgroundMore than 5 million patients with acute
chest pain present to emergency departments in the United States each year
Patients who are at highest risk for adverse outcomes derive the greatest benefit from glycoprotein IIb and IIIa inhibitor therapy and early revascularization
By contrast, patients at low risk may be discharged without a long-term effect on their risk of death or myocardial infarction
BackgroundThe term acute coronary syndrome (ACS)
describes clinical manifestations of acute myocardial ischemia induced by coronary artery disease
The rate of missed diagnosis of acute coronary syndromes, which remains unacceptably high (2%–4%), is associated with a twofold increase in mortality
This factor contributes to a low threshold for hospital admission of patients with chest pain by emergency department physicians.
Consequences of a missed acute coronary syndrome, and resultant liability issues (20% of emergency department malpractice dollar losses), and more than 2 million patients with acute chest pain are unnecessarily admitted to the hospital
BackgroundShort examination times of approximately
5 minutes and robust image quality, multidetector cardiac CT constitutes a highly attractive approach for initial work-up in the emergency department setting.
Patient Selection and PreparationContraindication
history of severe allergic reaction to an iodinated contrast material
impaired renal function (creatinine level of > 1.5 mg/dL)
Ideal Patients : Have a normal sinus rhythm, Targeted heart rate of less than 65 beats per
minute during image acquisitionHeart rate should be measured during a breath-
holding test to determine whether the
administration of a ß-blocker is necessaryheart rate often decreases by 5–10 beats per minute
during the first few seconds of a postinspiration breath hold
ß-blocker (eg, 5–20 mg of metoprolol) immediately before the CT examination
A Standard CT Protocol1. Localization:
projectional anteroposterior topographic scan of the chest. The imaging volume should extend from 1–2 cm below the
carina to the bottom of the heart.2. Determination of Contrast Agent Transit Time:
15 mL of the contrast agent, immediately followed by 40 mL of saline, is injected at a flow rate of 5 mL/sec
Scanning is initiated 10 seconds after the start of the contrast medium injection
Axial images are acquired at the level of the aortic root (10-mm collimation) at intervals of 2 seconds and are instantly displayed
3. Data Acquisition: Images are acquired in helical mode during injection of 60–
100 mL of the contrast agent followed by 40 mL of saline solution, at a rate of 4–5 mL/
sec
A Standard CT Protocol The short scan duration of 12 to 15 seconds permits a
breath-hold imaging duration that can capture homogenous contrast opacification around the narrow peak of contrast enhancement
Optimal image quality usually can be achieved in diastole (starting at approximately
65% of the R-R cycle)
Images typically reconstructed with 1-mm section thickness and a 0.5-mm overlap at 16-section multidetector CT and with a 0.75-mm section thickness and 0.4-mm overlap at 64-section multidetector CT
Nearly isotropic resolution (voxel size, 0.4 x 0.4 x 0.6 mm) permits reformatting of images in any arbitrary plane without a significant loss of image information.
ECG triggering and gating ECG triggering:
the scanner acquires data only for a defined period after the signal from the R wave of the ECG trace.
“step and shoot” scan technique an image is acquired every second heartbeat to
allow table translation between image generation ECG gating:
the scanner acquires data in a nonstop, helical mode while an independent ECG trace is generated at the same time
Images are acquired both during systole and diastole
ECG triggering and gatingTo
summarize: TriggerTrigger GatingGating
ECG to acquire data and is prospective
ECG to reconstruct data and is retrospective
“Step and shoot”
Continuous
coronary calcification scoring
aortic root imaging
required for coronary artery CTA
Multiplanar Imaging- Key= Temporal Resolution The advent of multidetector CT (MDCT),
particularly with scanners having 64 or more detectors, has continued to improve temporal resolution (TR).
TR may be thought of as the “shutter speed” of the scanner and is the key to recent advancements in MDCT technology. Temporal resolution in the region of 100 msec is required to create relatively motionless images of the beating heart
Thus, the heart and coronary arteries are routinely imaged as a motion-free volume of data and is reconstructed in multiple formats:Multiplanar reformation (MPR), maximum intensity
projection (MIP), volume rendering (VR), curved reformation, and cine imaging
Multidetector CT Postprocessing TechniquesMultiplanar Reformation
• MPR is the basic tool used to interpret cardiac CT angiographic studies
• Data from specific phases of the cardiac cycle are retrospectively referenced to the electrocardiogram for reconstruction
• The workstation allow images of the heart and coronary arteries to be manually rotated for optimal evaluation of the cardiac anatomy
• Automatically orient data sets along the cardiac axes and into the traditionally used cardiac planes (ie, short-axis, horizontal long-axis, vertical long-axis)
Multidetector CT Postprocessing TechniquesMaximum Intensity Projection
Technique that takes the highest-attenuation voxel in a predetermined slab of data and projects it from the user toward the viewing screen, resulting in a two-dimensional image.
similar to traditional angiograms, which display intraluminal opacity values
can allow quick assessment for significant coronary artery stenosis
limitation of MIP images is that they lack depth and spatial information
Multidetector CT Postprocessing TechniquesVolume Rendering
3D technique in which the CT attenuation values for
each voxel can be assigned a specific color, thereby producing an overall image of the heart
only true 3D technique and provides the depth and spatial information that is lacking with MIP
facilitate surface evaluation of the heart and coronary arteries
useful for evaluating complex anatomy, including coronary artery anomalies, bypass grafts, and fistulas
easily understandable format for referring physiciansuseful also for surgical planning
Multidetector CT Postprocessing TechniquesCurved Reformation
Coronary arteries are often tortuous, accurate
evaluation requires assessment of the entire vessel along its center line
Curved reformatted images provide this capability
by sampling a given volume (ie, artery) along a predefined curved anatomic plane
Most useful for depicting the lumen of a coronary
artery from its ostium to its distal end.Is especially helpful in patients with bypass grafts
and highly tortuous coronary arteries
Multidetector CT Postprocessing TechniquesCine Imaging
examine the motion and physiologic features of cardiac structures such as the LV and cardiac valves
data from the heart and coronary arteries are typically reconstructed at specific points during the cardiac cycle, ie. Examine certain anatomy during systole and
diastoleparticularly useful for examining LV wall motion and wall
thickening and for assessing valve motion in multiple planes
reconstruction of the cardiac data during both systole and diastole allows determination of quantitative LV functional parameters, including end-diastolic and end-systolic ventricular volumes, stroke volume, and ejection fraction
Ventricular FunctionLeft Ventricle Normal Function
Right Ventricle Normal Function
Radiation Exposure at CT Coronary Angiography ECG-controlled dose modulation technique is used to
reduce the tube current during systole,The effective radiation dose is 6.7–7.6 mSv in men and
8.1–9.2 mSv in womenFor 64-section scanners, the radiation dose at cardiac CT
is 6.9–11.1 mSvWithout tube current modulation, the radiation dose is
estimated to be approximately 16–20 mSvBy comparison, a mean effective radiation dose of
approximately 5 mSv is incurred at selective coronary angiography RadioGraphics 2006;26:963-978
The estimated total body radiation exposure after a 16 slice MDCT coronary angiogram is 2 to 3 times the average exposure from a diagnostic catheterization but similar or lower than the exposure from a rest-stress myocardial scintigraphic study
Coronary ArteriesBy general consensus,
the coronary artery tree is divided into 17 segments, according to the AHA system of classification
Coronary Anatomy- Segments
Axial CT image (0.75-mm section thickness) at the midventricular level shows a middle segment of the right coronary artery (RCA) and distal segments of the left anterior descending and left circumflex branches.
The latter is seen in the left atrioventricular groove, in close proximity to the great cardiac vein (GCV).
Coronary Anatomy- Segments Axial MIP image (5-mm section
thickness) at the level of the bottom of the heart shows a distal segment of the RCA at the origins of the posterior descending artery (PDA) and the posterior left ventricular (PLV) artery.
The posterior descending artery is seen in the posterior longitudinal sulcus, in close proximity to the middle cardiac vein (MCV).
A distal segment of the LAD also is visible.
This case demonstrates right coronary artery dominance in blood supply to the ventricles, a common finding (85%–90% of patients).
Y’all hold on, Here we go in…
Left Main Coronary Artery (LCA)Usually the first coronary artery seen
(starting superiorly from its origin)Normally arises from the left sinus of
Valsalva near the sinotubular ridge Courses posterior to the right
ventricular outflow tract (RVOT), and bifurcates into the left anterior descending (LAD), and the left circumflex (LCX) branches.
In about 15% of patients, a separate intermediate branch, or ramus intermedius (RI), also arises from the left main coronary artery
LCA Segmental Anatomy 5 = main artery, 6 = proximal segment of the left
anterior descending (LAD) branch, 7 = middle segment of the LAD
branch, 8 = distal segment of the LAD
branch, 9 = first diagonal branch, 10 = second diagonal branch, 11 = proximal segment of the left
circumflex (LCX) artery, 12 = first obtuse marginal branch
of the LCX artery, 13 = middle segment of the LCX
artery, 14 = second obtuse marginal
branch of the LCX artery, 15 = distal segment of the LCX
artery, 17 = intermediate branch
LCA segmental Anatomy 5 = main artery, 6 = proximal segment of the left
anterior descending (LAD) branch, 7 = middle segment of the LAD
branch, 8 = distal segment of the LAD
branch, 9 = first diagonal branch, 10 = second diagonal branch, 11 = proximal segment of the left
circumflex (LCX) artery, 12 = first obtuse marginal branch of
the LCX artery, 13 = middle segment of the LCX
artery, 14 = second obtuse marginal
branch of the LCX artery, 15 = distal segment of the LCX
artery, 17 = intermediate branch
The arrowhead in indicates the mid intermediate branch
LCA
VR image shows the LCA (black arrow) arising from the aorta and bifurcating into the proximal LCx artery (arrowhead) and the proximal LAD artery (white arrow).
The LCA (black arrow) bifurcates into the left anterior descending (LAD) artery (white arrowhead) and the left circumflex (LCx) artery (black arrowhead). White arrow indicates the right coronary artery (RCA).
LCA LAD The LAD artery courses
anterolaterally in the epicardial fat of the anterior interventricular groove and supplies the majority of the LV
The LAD artery is divided into proximal, middle, and distal portions
The midportion of the LAD artery extends to the point where the artery forms an acute angle
The apical segment represents the termination of the artery. Oblique axial (top) and vertical
long-axis (bottom) MPR images show the normal LAD artery (arrows) coursing in the epicardial fat of the interventricular groove toward the LV apex
LCA LAD Diagonal Septal
The major branches of the LAD artery are the diagonal and septal perforating arteries. The diagonal branches
course laterally and predominantly supply the LV free wall.
The septal branches course medially and supply the majority of the interventricular septum, as well as the atrioventricular (AV) bundle and proximal bundle branch.
Septal branches (black arrowheads)
diagonal branches (white arrowheads) of the LAD artery
LCA LCxDivided into proximal and distal segments,
based on the origin of the (usually large) obtuse marginal branches
Courses in the left AV groove, giving rise to obtuse marginal branches --
sometimes referred to as lateral branchesSupply the LV free wall and a variable portion
of the anterolateral papillary muscle Variably gives rise to posterolateral and
posterior descending artery (PDA) branches supplying the diaphragmatic portion of the LV
LCA LCx Obtuse MarginalsOblique axial MPR
(top) and VR (bottom) images show the LCx artery (black arrow) and obtuse marginal branches (white arrows).
LCA Ramus Intermedius In approximately 15% of
patients, a third branch, the ramus intermedius (RI) branch, arises at the division of the LCA, resulting in a trifurcation
When present, the RI branch courses toward the LV free wall, similar to that of a diagonal branch of the LAD artery.
RI branch (arrow) arising between the LAD artery (black arrowhead) and the LCx artery (white arrowhead), resulting in a trifurcation of the LCA
Right Coronary Artery (RCA) Normally arises from the right
coronary sinus (CS) and courses in the right AV groove toward the crux of the heart
The proximal RCA extends from the ostium to a point halfway to the acute margin of the heart
Approximately 50%–60% of patients, the first branch of the RCA is a conus artery conus artery supplies the RV
outflow tract (conus arteriosis) and forms the circle of Vieussens, an anastomosis with the LAD arterial circulation
RCA Segmental Anatomy 1 = proximal segment of the
main artery, 2 = middle segment of the main
artery, 3 = distal segment of the main
artery, 4 = posterior descending
branch, 16 = posterior left ventricular
branch, CB = conal branch, SN = sinonodal branch
RCA Segmental Anatomy 1 = proximal segment of the
main artery, 2 = middle segment of the main
artery, 3 = distal segment of the main
artery, 4 = posterior descending
branch, 16 = posterior left ventricular
branch, CB = conal branch, SN = sinonodal branch AM = acute marginal branch
RCA Branches Sinoatrial nodal artery
arises from the RCA in 58%; in the remaining patients (42%), it arises from the LCx artery
Multiple ventricular branches arise from the RCA, the largest of which is called the acute marginal branch
MPR images (top,left) and VR image (right) show the RCA (black arrow) and its branches. In this case, the conus artery (long arrow) arises from the aorta.
White arrow in top and arrow in left indicate the acute marginal branch, arrowhead in right indicates the sinoatrial nodal branch
DominanceThe coronary artery that gives rise to the PDA
and posterolateral branch is referred to as the "dominant" arteryRCA is dominant in about 70% of casesLCA in 10% of cases, supplying the entire LVRemaining cases (20%), the RCA and LCA are
codominant; that is, portions of the LV diaphragmatic wall are supplied by both the RCA and the LCx artery
The length of the distal RCA is inversely proportional to the length of the LCA along the inferior aspect of the heart
Dominance
A right-dominant system:PDA (white arrowhead) arising from the RCA (black arrowhead). A posterolateral branch (arrow) is also seen.
A codominant system, with the inferior myocardial surface supplied equally by the RCA and the LCx artery
Normal Coronary Artery DiameterThe average size varies with gender
(approximately 3 mm in females and 4 mm in males)
each coronary artery also vary, ranging from 5 mm (LCA in males) to 2 mm (PDA in females)CCTA guidelines have not been published, and
the above are based on angiographic data.Focal abnormal dilatation to more than 1.5
times the diameter of an adjacent normal coronary artery is defined as an aneurysm
Normal Coronary Artery DiameterIf the process is
diffuse, it is known as ectasia .
Either process is easily identified with cardiac CT angiography
VR images obtained in an adolescent with Kawasaki disease show a focal RCA aneurysm (arrowhead).
Cardiac and Pulmonary VeinsExcellent for imaging the Coronary Sinus
(CS) and cardiac veinsThe most constant structure is the CS itself,
which runs along the inferior aspect of the heart in the AV groove before emptying into the RA1st branch of the CS is the middle cardiac vein,
which courses in the posterior interventricular
groove from base to apexNext two branches are the posterior vein of the
LV and the left marginal veinThe CS becomes the great cardiac vein
Cardiac Veins
CS (arrowheads) coursing along the inferior surface of the heart and emptying into the RA. In this case, the posterior vein of the LV (white arrow) is prominent and the left marginal vein is absent. Black arrow indicates the posterior interventricular vein
VR image shows the great cardiac vein (arrowheads) coursing in the left AV groove.
Cardiac VeinsVariability in the cardiac veins is usually due to
absence of either the left marginal vein or the posterior vein of the LV.
Whys is this relevant?Patients treated with cardiac resynchronization
therapy typically undergo implantation of an automatic cardioverter-defibrillator for the treatment of heart failure, ideally with a transvenous approach.
If no suitable vein is present in which to place the LV pacer lead with a transvenous approach, surgical placement may be necessary
Pulmonary Veins
The PVs also receive significant attention because of ablation therapy.
LA muscle can extend into the venous ostia, and ectopic electrical foci originating at this site may be the cause of atrial fibrillation in a significant number of patients
If additional PVs are present, it is important that they be described prior to ablation. They are typically single and occur more commonly on
the right sideMiddle PVs arising on the right side have a stronger
association with atrial fibrillation
Atrial AppendagesPatients with atrial fibrillation may develop
thrombus in the LA appendage, a condition that can be evaluated with multidetector CT prior to PV ablation>97%, the LA appendages have pectinate
muscles measuring greater than 1 mmLA appendage arises from the superolateral
aspect of the LA and projects anteriorly over the proximal LCx artery
Atrial Appendage normal RA
appendage (arrow) and pectinate muscles
Vertical long-axis MPR image shows the normal LA appendage (arrow). The linear filling defects in the appendage represent normal pectinate muscles
Cardiac Valves The four cardiac valves are routinely imaged during
cardiac CT angiography, and their motion and morphologic characteristics also assessed at all cardiac CT angiographic examinations with reconstructed and cine images.
The MV is composed of two leaflets, the anterior and posterior leaflets; the other valves normally have three leafletsCalcification of the MV annulus is a common abnormality
that makes identification of the annulus possibleThe papillary muscles with their chordae tendineae are also a
component of the MV apparatus The tricuspid valve separates the RA from the RV and is
connected to the RV
Cardiac Valves
•The aortic valve separates the LV outflow tract from the ascending aorta.
• It is composed of an annulus, cusps, and commissures.
• No papillary muscles or chordae tendineae are associated with the aortic valve
AO valve: Cusps are the right coronary cusp (white *), the left coronary cusp (black *), and the noncoronary cusp (box)
Pericardium Normally paper thin, measuring
2 mm or less It is composed of two layers, the
parietal layer and the serous layer
The pericardium lining the surface of the heart is known as the visceral pericardium, or epicardium.
It is important to be aware of the more common recesses and
sinuses to distinguish them from lymphadenopathy or abnormal
soft tissue
Not too much more.. Now some practical stuff.
Cardiac CT Angiography
A Brief Look at Practical Applications
Relevant Findings at Cardiac CT Data from clinical trials in patients with ACS indicate that
the detection of a significant stenosis may help improve risk stratification.
Most patients with unstable angina or non–ST-segment-elevation myocardial infarction (80%–94%) – show a significant coronary stenosis at coronary angiography
Several studies with intravascular ultrasonography (US) demonstrated that many coronary atherosclerotic lesions that cause acute events have a distinct morphology that includes a thrombus, a small residual vessel lumen, a greater plaque burden, and more pronounced positive remodeling
So what does all this mean to CCTA?
Show me the Money $$ The detection and detection and
characterization of characterization of coronary atheroscleroticcoronary atherosclerotic
plaque plaque may aid in the identification of patients at risk for an acute coronary syndrome
The primary use for coronary multidetector CT may be in patients with an intermediate likelihood of experiencing an acute coronary syndrome
Coronary PlaquesThe sensitivity of CCT is greater for
calcified (94%) than for mixed (78%) or soft (53%) plaques and is mostly limited to large-caliber vessels
Compared with intravascular ultrasound, CCT tends to underestimate the noncalcified plaque volume but to overestimate the calcified plaque volume
Stenosis of the Widow Maker Significant stenosis of the left
anterior descending artery in a 67-year-old patient with unstable angina and multiple risk factors (history of premature coronary artery disease, hypercholesterolemia, hypertension) but negative results at testing for biochemical markers and no acute ECG changes.
(top) Axial thin-section (5-mm) MIP image from a 64 MDCT shows a significant luminal narrowing (arrowhead) in the middle segment of the artery.
(bottom) Selective coronary angiogram demonstrates an eccentric high-grade (94%) stenosis (arrowhead).
CABGIt is of proven value in
evaluating the patency of bypass grafts
But, limited in evaluating the anastamosis and small-vessel disease beyond the anastamosis
Recent Data The results a large multicenter study published in JAMA in 2006
(n=238)demonstrated a higher number of false-positive and nonevaluable segments using a 16 MDCT
Of 1629 nonstented segments larger than 2 mm in diameter, there were 89 (5.5%) in 59 (32%) of 187 patients with stenosis of more than 50% by conventional angiography. Of the 1629 segments, 71% were evaluable on MDCT
sensitivity for detecting more than 50% luminal stenoses was 89%; specificity, 65%; positive predictive value, 13%; and negative predictive value, 99%
They concluded that this may be useful in excluding coronary disease in selected patients in whom a false-positive or inconclusive stress test result is suspected.
Garcia M. et al. Accuracy of 16-Row Multidetector Computed Tomography for the Assessment of Coronary Artery Stenosis. JAMA. 2006;296:403-411
More Recent Data Using a 64 MDCT Sensitivity for the detection of stenosis <50%,
stenosis >50%, and stenosis >75% was 79%, 73%, and 80%, respectively, and specificity was 97% Leber A. et al. Quantification of Obstructive and Nonobstructive Coronary
Lesions by 64-Slice Computed Tomography. J Am Coll Cardiol, 2005; 46:147-154
A large Meta-analysis of the literature included 38 studies demonstrated overall that 64 spiral CT has significantly higher specificity and PPV on a per-patient basis compared with 16-section CT for the detection of greater than 50% stenosis of coronary arteries. Hamon M. et al. Coronary Arteries: Diagnostic Performance of 16- versus 64-Section Spiral
CT Compared with Invasive Coronary Angiography—Meta-Analysis (Radiology 2007;245:720-731.)
SPECT MPI As a comparisonFindings of multiple studies have shown
sensitivity ranging from 90% to 100%, specificity from 60% to 78%, and negative predictive value from 97% to 100% at radionuclide perfusion imaging for ACS if single photon emission computed tomography (SPECT) imaging is used
White C, Kuo D. Chest Pain in the Emergency Department: Role of Multidetector CT. Radiology 2007;245:672-681.
Example Case CT and radionuclide perfusion images
in a 67-year-old man who presented to the ED with atypical chest pain.
(a) Two-dimensional map of the coronary arteries from a CT triple rule-out protocol shows substantial calcification with areas of stenosis in the left anterior descending (LAD) and right coronary arteries (RCA). AcuteMarg = acute marginal, D1 = first diagonal, D2 = second diagonal, LCX = left circumflex artery.
(b) Curved planar reconstructed view of right coronary artery demonstrates substantial calcified and noncalcified plaque causing luminal narrowing (arrows).
(c) Radionuclide perfusion image shows a defect (arrow) in the inferior myocardial wall.
Calcium ScoringMost widely used measure of calcium burden is the
calcium score (often known as the Agatston score), which is based on the radiographic density–weighted volume of plaques with attenuation values of greater than 130 Hus
Several studies have indicated that the calcium score provides prognostic information independent of conventional risk factorsgreater than 300 was associated with a significant
increase in cardiac events Radiology 2005;235:415-422.)
© RSNA, 2005Cardiac Imaging
Coronary Artery Stenoses: Detection with Calcium Scoring, CT Angiography, and Both Methods Combined1
George T. Lau
Diagnostic Value of Coronary Calcification Findings
Results of these studies demonstrate a high negative predictive value of the absence of coronary calcifications for acute coronary syndrome
The characteristics of coronary calcification in patients with stable angina were found to differ from those in patients with unstable angina
Electron-beam CT was used to evaluate coronary arteries in all patients in the three studies listed1999-2000.
•However, the diagnostic value of a finding of coronary calcification is controversial.
• In a study by Greenland 2004, 14% of events (myocardial infarction and death) were observed in patients in whom no evidence of
coronary calcification was found at CT
Bottom Line Appropriate indications for CCT are as follows:
chest pain: intermediate pretest probability for CAD (ECG cannot be interpreted or patient is unable to exercise), persistent chest pain after equivocal stress test, or suggestion of coronary anomalies;
acute chest pain in emergency department: intermediate pretest probability for CAD (no changes in ECG and negative enzyme test results);
pulmonary vein isolation, biventricular pacemaker implantation, or coronary arterial mapping in repeat cardiac surgery;
cardiac masses or pericardial disease with technically limited images from echocardiogram, MRI, or transesophageal echocardiography;
complex congenital heart disease: assess anatomy.
Gonzalez SP, Sanz J, Garcia M. Cardiac CT: Indications and Limitations. Journal of Nuclear Medicine Technology. Vol 36, Num 1, 2008 18-24.
Bottom Line Uncertain indications for CCT are as follows:
chest pain: intermediate pretest probability for CAD (ECG can be interpreted and patient is able to exercise) or low or high pretest probability for CAD (no changes in ECG and negative
enzyme test results);
acute chest pain: rule out obstructive CAD, aortic dissection, and pulmonary embolism if the pretest probability for one of them is intermediate;
high risk of CAD in asymptomatic patients;
chest pain after revascularization (percutaneous intervention or coronary artery bypass grafts): evaluate bypass grafts or history of revascularization with stents;
intermediate perioperative risk of cardiac events in patients undergoing intermediate- or high-risk noncardiac surgery;
valvular disease (native or prosthetic valves) with technically limited images from ECG, MRI, or transesophageal echocardiogram.
Gonzalez SP, Sanz J, Garcia M. Cardiac CT: Indications and Limitations. Journal of Nuclear Medicine Technology. Vol 36, Num 1, 2008 18-24.
References: O’ Brien J, Srichai M, Hecht E. Anatomy of the Heart at
Multidetector CT: What the Radiologist Needs to Know.
RadioGraphics 2007;27:1569-1582 Lawler L. CT scanning of the coronary arteries: How to do it and how to
interpret it. Applied Radiology. Volume: 34 Number: 10 October 2005. Hoffman U, Pena A, Cury R. Cardiac CT in Emergency Department Patients
with Acute Chest Pain1 RadioGraphics 2006;26:963-978. Lau G. Et al. Coronary Artery Stenoses: Detection with Calcium Scoring, CT
Angiography, and Both Methods Combined1 Radiology 2005;235:415-422. Mollet N, Cademartiri F, Van Meighem C. et al. High-Resolution Spiral
Computed Tomography Coronary Angiography in Patients Referred for Diagnostic Conventional Coronary Angiography Circulation. 2005;112:2318-2323.
Thank YOU for your Attention !!!