This document addresses contrast-enhanced computed tomography angiography (CTA) of the coronary arteries (coronary CTA or CCTA) and magnetic resonance angiography (MRA) of the coronary arteries. 

Note: This document does not address the use of electron beam computed tomography (EBCT) to quantify coronary calcification, which is addressed in RAD.00001 Computed Tomography to Detect Coronary Artery Calcification.  

 For further information regarding the use of CTA/MRA imaging for additional indications, refer to:

• Clinical UM Guideline CG-RAD-08 CTA/MRA Head and Neck;
• Clinical UM Guideline CG-RAD-09 CTA/MRA of Thorax, Abdomen and Extremities.

Medically Necessary: 

Contrast-enhanced coronary computed tomography angiography (CCTA) or coronary magnetic resonance angiography (MRA) is considered medically necessary for the evaluation of suspected anomalous coronary arteries when conventional angiography has been unsuccessful or has provided equivocal results and the results could impact treatment. 

Investigational and Not Medically Necessary:

Coronary computed tomography angiography (CCTA) or coronary magnetic resonance angiography (MRA) is considered investigational and not medically necessary for all other indications, including, but not limited to, the following:

• Screening for coronary artery disease (CAD), either in asymptomatic subjects or as part of a preoperative evaluation;
• Diagnosis of CAD, in patients with acute or non-acute symptoms, or after a coronary intervention;
• As a technique to evaluate cardiac function.

Coronary CT Angiography

Coronary CT Angiography (CCTA) to Detect Coronary Artery Disease (CAD)
Over the past several years, a large number of studies have addressed the diagnostic accuracy of coronary CT angiography (CCTA) in the evaluation of coronary artery disease (CAD).  Studies can be broadly subdivided into those that address the use of CCTA in patients with acute symptoms suggestive of CAD, and in patients considered at intermediate risk for coronary artery disease, based either on symptoms, risk factors, or equivocal results of other cardiac imaging procedures, such as myocardial perfusion imaging (MPI) or echocardiography.  In the setting of acute symptoms, CCTA has frequently been assessed as an emergency room triage technique to rapidly rule myocardial infarction either in or out.  In the setting of non-acute symptoms, CCTA has been investigated primarily as a technique to determine candidacy for a subsequent invasive coronary angiography.  Specifically, if a CCTA is considered normal, then a patient may forgo a coronary angiogram.  Early studies of CCTA reported results from 16 row detectors and reported diagnostic outcomes according to the number of vessels or segments visualized.  More recent literature has focused on 64 row detectors, which have greater spatial resolution, and have also reported diagnostic outcomes in terms of the individual patient.  This latter analysis has been considered more appropriate than per vessel or segment analysis, since treatment decisions are made on a per-patient basis.  It should also be noted that the majority of studies enrolled patients who were scheduled to undergo invasive coronary angiography for a variety of reasons.  Therefore, invasive angiography represented the comparator gold standard imaging technique. 

This large volume of studies was recently reviewed as part of a scientific statement published by the American Heart Association Committee on Cardiovascular Imaging and Intervention of the Council on Cardiovascular Radiology and Intervention (Bluemke, 2008).  This review noted that the presence of hemodynamically relevant coronary artery stenoses in patients without bypass grafts or stents may be ruled out by CCTA with a high negative predictive value, ranging from 98-100% in most studies.  This high negative predictive value of CCTA forms the basis for the assertion that CCTA may be useful to identify patients who would not benefit from coronary angiography.  In contrast, the positive predictive value of CCTA may not be clinically relevant in patients at high risk for CAD based on symptoms, risk factors or other imaging techniques.  These patients would most likely benefit from invasive angiography, since the likelihood is high that interventional treatment at the time of angiography would be necessary.  Data regarding CCTA detection of restenosis in patients with coronary bypass grafts or intracoronary stents is more limited.

A 2008 study by Miller and colleagues is reviewed as a representative study of the diagnostic performance of CCTA (Miller, 2008).  This multicenter study enrolled 291 patients with suspected CAD who underwent CCTA prior to a scheduled invasive coronary angiogram.  The specific indications for the coronary angiogram or results of other imaging procedures (i.e., echocardiography or myocardial perfusion imaging) were not provided.  The primary outcome was the accuracy of CCTA in detecting stenoses of 50% or more compared to the gold standard of invasive coronary angiography, based on a per-patient analysis.  Accuracy was measured as the area under the receiver operating curve (AUC).  The following statistics were reported:

The authors concluded that an AUC of 0.93 indicates that CCTA using a 64 row detector has powerful discriminative ability among symptomatic patients to identify those with and without CAD.  However, the negative predictive value of 83% is lower than other reports (Hausleiter, 2007; Haussman, 2008; Schlosser, 2007; Cademartini, 2007), and the authors state that, on this basis, CCTA cannot replace invasive coronary artery angiography in this population of symptomatic patients.  The lower negative predictive value in this well controlled multi-center study is important to consider, particularly since a high negative predictive value forms the scientific rationale for the proposed clinical utility of CCTA to deselect patients for invasive coronary angiography.  The authors hypothesize that the higher negative predictive value in other studies may be related to the limitations inherent in single-center designs and the degree of rigor used in controlling for bias in smaller studies.  Heterogeneity in study results has also been noted in a 2006 meta-analysis by Hamon and colleagues.  Miller and colleagues conclude by stating, "Further studies are needed to define [CCTA's] precise role in the diagnostic algorithm for the evaluation of patients with suspected coronary artery disease."

This last statement by the authors highlights a crucial point in the consideration of CCTA as a technique to diagnose CAD.  Specifically, the diagnostic accuracy essentially represents an intermediate outcome.  The final health outcome is related to how CCTA can be integrated into the overall management of the patient, considering both patient risk factors and the role of other established imaging methods, such as myocardial perfusion imaging or echocardiography.  Both of these well established imaging techniques assess the functional significance of any stenosis, as opposed to the anatomy of the stenosis, as imaged by CCTA.  While many studies have hypothesized that CCTA can be used to deselect patients for invasive angiography, this hypothesis has not been assessed in controlled trials or in registry reports. It is not clear what the final health outcome is for patients with an intermediate risk of CAD who have negative results from CCTA. For example, registry reports can provide important information regarding whether these patients undergo angiography.  Randomized trials could compare the efficacy of CCTA vs. myocardial perfusion imaging as the initial study in patients with suspected CAD.  Efficacy could be measured by a variety of cardiac outcomes assessed over medium and long term follow up.

Diagnostic accuracy is sometimes considered an adequate intermediate surrogate outcome in situations where there are limited other diagnostic techniques, or there are significant limitations in the gold standard.  However, this is not the case for the evaluation of CAD where there are multiple other diagnostic techniques.  Another consideration is the safety of CCTA.  In the trial by Miller, the mean effective dose of radiation was 14mSv for men and 15 mSv for women, which exceeds that of coronary angiography.  Even assuming a more conservative estimate of 8 mSv for a CCTA, the radiation dose is still 400 times the radiation dose of one chest x-ray.  This radiation dose places CT scans at an intermediate (1–10 mSv) to moderate (10 mSv) level of risk under international guidelines, a risk level for which the corresponding benefit should be "moderate" to "substantial."  Einstein and colleagues (2007) reported that their "Simulation models suggest that use of 64-slice CTCA is associated with a non-negligible LAR (lifetime attributable risk) of cancer" and that the risk is "Considerably greater for women, younger patients and for combined cardiac and aortic scans."  Like coronary angiography, CTA also presents the risk of renal damage from the use of nephrotoxic contrast agents and of complications from the use of medicines to slow the heart rate to obtain a usable image.  In addition, depending on how CCTA is integrated into cardiac work-up, the patient could be exposed to multiple different imaging tests with cumulative radiation exposure, particularly if CCTA results in an additional layer of imaging.   

The need for final health outcomes to define the role of CCTA in the hierarchy of imaging tests is highlighted by an editorial accompanying the Miller study which noted, "Some proponents argue that diagnostic cardiac CT angiography should not be held to the same outcome standard as therapeutic procedures, since diagnostic procedures are not directly responsible for improved outcomes.  However, the value of diagnostic tests lies in whether, by leading to a more appropriate choice of therapy, they ultimately result in better outcomes … Although [the Miller study] was carefully done and provides more data on diagnostic accuracy, it does not advance our knowledge of the appropriate use and possible benefits of the technology… Because all patients received both cardiac CT angiography and conventional coronary angiography and no data on outcomes are reported, the study does not answer this important question." (Redberg 2008) 

The lack of health outcomes data that go beyond reports of diagnostic accuracy are the basis of the position statement identifying CCTA as an investigational technique to diagnose coronary artery disease.

In contrast, other organizations consider diagnostic accuracy an outcome adequate to support the routine use of CCTA in the evaluation of CAD.  As noted above, in 2008 the American Heart Association Committee on Cardiovascular Imaging and Intervention of the Council on Cardiovascular Radiology and Intervention published a scientific statement on CCTA to evaluate CAD (Bluemke 2008).  Based on their literature review, the statement offered recommendations categorized according to the following criteria, based on class or recommendation and level of evidence.  As noted, Class II recommendations include both the weight of evidence and opinion. 

• Class I: Conditions for which there is evidence and/or general agreement that a given procedure or treatment is beneficial, useful, and effective.
• Class II:  Conditions for which there is conflicting evidence and/or divergence of opinion about the   usefulness/efficacy of a procedure or treatment.
  • Class IIa: Weight of evidence/opinion is in favor of usefulness/efficacy.
  • Class IIb:   Usefulness/efficacy is less well established by evidence/opinion.
• Class III: Conditions for which there is evidence and/or general agreement that a procedure/treatment is not useful/effective and in some cases may be harmful.  (Budoff, 2006)

Level of Evidence A: Data derived from multiple randomized clinical trials or meta-analyses.
Level of Evidence B: Data derived from a single randomized trial or nonrandomized studies.
Level of Evidence C: Only consensus opinion of experts, case studies, or standard-of-care.

 The specific recommendation regarding CCTA for diagnosis of CAD is as follows:

• The potential benefit of noninvasive coronary angiography is likely to be greatest and is reasonable for symptomatic patients who are at intermediate risk for coronary artery disease after initial risk stratification, including patients with equivocal stress tests.  (Class IIa, level of evidence B)

In 2006, the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group published appropriateness criteria for cardiac computed tomography and cardiac magnetic resonance imaging (Hendel, 2006). This report took a consensus approach rather than purely evidence-based approach to develop the appropriateness criteria.  Appropriateness criteria ranging from 0 to 9 were assigned to different clinical situations, where a score of 7-9 indicated an appropriate test, 4 to 6 indicated uncertainty regarding the specific indication, and a score of 1 to 3 identified an inappropriate test.  Appropriateness scores for similar clinical indications have been developed for myocardial perfusion imaging (MPI). (Douglas 2006) The following table summarizes the appropriate indications for CCTA and MPI for the diagnosis of CAD. 

Interpretation of the appropriateness scores is limited due to their consensus basis, but it is interesting to note that a myocardial perfusion scan is considered as appropriate or more appropriate as CCTA in the evaluation of a chest pain syndrome.

Summary
A variety of studies and meta-analyses have reported that CCTA has a high negative predictive value for CAD, and that CCTA is a potentially useful technique to deselect patients for invasive coronary artery angiogram, particularly those patients considered to be at intermediate risk of CAD.  These studies, and resultant clinical recommendations and appropriateness criteria, have focused on the diagnostic accuracy of CCTA.  In contrast, there are inadequate data to support the clinical utility of CCTA, specifically how CCTA will be integrated into the management of patients with suspected CAD, and how CCTA will ultimately improve patient outcomes.  These final health outcomes are considered important, due to multiple other imaging and evaluation options.  In addition, CCTA is associated with significant radiation exposure, which is a concern given that some patients may undergo multiple imaging tests.  Therefore, the lack of health outcomes data that go beyond reports of diagnostic accuracy are the basis of the position statement identifying CCTA as an investigational technique to diagnose coronary artery disease.

Coronary CT Angiography to Evaluate Anomalous Coronary Arteries
Anomalous coronary arteries are an uncommon finding at angiography, occurring in ~1% of coronary angiograms completed for evaluation of chest pain.  However, these congenital anomalies can be very important clinically depending on the course of the anomalous arteries.  Projection x-ray angiography has traditionally been the preferred imaging technique for the diagnosis and characterization of anomalous arteries.  However, conventional angiography is considered a flawed gold standard; sometimes the anomalous artery is not well visualized, and the declining use of pulmonary artery catheters during conventional angiography makes it more difficult to discern the anterior versus posterior trajectory of the anomalous artery.

Given the low incidence of this condition, it is not surprising that there is relatively limited literature compared to the literature addressing the diagnosis of CAD.  Existing studies consist of case series comparing CCTA with conventional angiography.  As noted in the review of the literature by Bluemke and colleagues, 7 case series enrolling a total of 161 patients have been reported.  In all but one study, the CCTA correctly identified the anomalous artery, with one exception where 29 of 30 of the arteries were correctly identified.  However, none of the studies discussed the impact on therapeutic decisions.  Even though the literature focuses on diagnostic accuracy as opposed to final health outcome, in this specific situation the limited outcome of diagnostic accuracy is considered adequate to validate the medical necessity of CCTA to evaluate anomalous coronary arteries when conventional angiography is non-diagnostic and when the result will impact treatment.  Unlike CCTA as a technique to diagnose CAD, in this situation conventional angiography is considered a flawed gold standard and CCTA can provide valuable anatomic information when the angiography is considered equivocal.  

Coronary MRA to Detect Coronary Artery Disease (CAD)
Compared to coronary CTA (CCTA), there is more limited literature regarding coronary MRA as a diagnostic technique for CAD.  However, the same limitations apply, i.e., the majority of studies are single institution studies reporting diagnostic performance on a per-segment or per-artery basis, as opposed to the more clinically relevant per-patient basis.  As reviewed by Bluemke, the negative predictive value in the 17 reviewed studies ranged from 71-96%, which is generally lower than the values reported for CCTA.  The Bluemke review notes that the diagnostic accuracy of CCTA favors coronary MRA.  However, the main limitation in this literature is the lack of final outcome studies, similar to CCTA. 

Coronary MRA to Diagnose Anomalous Coronary Arteries     
A total of 6 studies including 109 patients undergoing MRA to diagnose anomalous coronary arteries were identified in the review by Bluemke.  In these studies, coronary MRA correctly identified the anomalous anatomy in 93-100% of cases.  Consideration of the medical necessity of coronary MRA for this indication is similar to CCTA for the same indication.  Therefore, coronary MRA is considered medically necessary when conventional angiography is either unsuccessful or equivocal.

Description of Coronary Contrast-enhanced Computed Tomographic Angiography (CCTA)
CCTA is a noninvasive imaging test that requires the use of intravenously administered contrast material and a high-resolution, high-speed CT machine (multi-detector row scanner) to obtain detailed volumetric images of blood vessels.  CCTA has been proposed as a noninvasive alternative to invasive coronary angiography, particularly in patients with an intermediate risk of significant coronary artery disease (CAD). 

Description of Coronary Magnetic Resonance Angiography (MRA)
MRA of the coronaries involves the use of traditional MRI technology while a gadolinium-based contrast agent is injected intravenously during image acquisition.  This technique does not involve radiation exposure, and the contrast agent, at the dose used for MRA, is not considered nephrotoxic.

CAD:  coronary artery disease 

Coronary contrast-enhanced computed tomography angiography: (CCTA) a non-invasive radiological imaging technique that utilizes iodinated contrast agents followed by rapid imaging with a multi-detector row scanner, in order to acquire images of coronary arteries

Magnetic resonance angiography: (MRA) a non-invasive radiological imaging technique that utilizes traditional MRI technology to provide detailed images of blood vessels

The following codes for treatments and procedures applicable to this document are included below for informational purposes.  Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage or these services as it applies to an individual member.

When services may be Medically Necessary when criteria are met:

When services are Investigational and Not Medically Necessary:
For the procedure codes listed above, when criteria are not met, for all other diagnoses, or when the code describes a procedure indicated in the Position Statement section as investigational and not medically necessary.

Peer Reviewed Publications: 

1. Berbarie RF, Dockery WK, Johnson KB, et al. Use of multislice computed tomographic coronary angiography for the diagnosis of anomalous coronary arteries.  Am J Cardiol. 2006; 98:402-406.
2. Brodoefel H, Reimann A, Burgstahler C, et al. Noninvasive coronary angiography using 64-slice spiral computed tomography in an unselected patient collective: Effect of heart rate, heart rate variability and coronary calcifications on image quality and diagnostic accuracy. Eur J Radiol. 2008; 66(1):134-141.
3. Budoff MJ, Gopal A, Gul KM, et al. Prevalence of obstructive coronary artery disease in an outpatient cardiac CT angiography environment. International J Cardiol. 2008; 129(1):32-36. Available at: http://www.ncbi.nlm.nih.gov/pubmed/17651836?ordinalpos=&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.SmartSearch&log$=citationsensor.  Accessed on January 20, 2009.
4. Bunce NH, Lorenz CH, Keegan J, et al.  Coronary artery anomalies: assessment with free-breathing three-dimensional coronary MR angiography.  Radiology.  2003; 227:201-208.
5. Cademartiri F, Mollet NR, Lemos PA, et al. Impact of coronary calcium score on diagnostic accuracy for the detection of significant coronary stenosis with multislice computed tomography angiography. Am J Cardiol. 2005; 95:1225-1227.
6. Cheng AS, Pegg TJ, Karamitsos TD, et al. Cardiovascular magnetic resonance perfusion imaging at 3-tesla for the detection of coronary artery disease: a comparison with 1.5-tesla.  J Am Coll Cardiol. 2007; 49(25):2440-2449. 
7. Datta J, White CS, Gilkeson RC, et al. Anomalous coronary arteries in adults: depiction at multi-detector row CT angiography.  Radiology. 2005; 235:812-818.
8. Deibler AR, Kuzo RS, Vohringer M, et al. Imaging of congenital coronary anomalies with multislice computed tomography.  Mayo Clin Proc. 2004; 79(8):1017-1023.
9. Dewey M, Teige F, Schnapauff D, et al.  Noninvasive detection of coronary artery stenoses with multislice computed tomography or magnetic resonance imaging.  Ann Intern Med. 2006; 145:407-415.
10. Ehara M, Surmely J, Kawai M, et al. Diagnostic accuracy of 64-slice computed tomography for detecting angiographically significant coronary artery stenosis in an unselected consecutive patient population. Circ J. 2006; 70:564–571.
11. Ehara M, Kawai M, Surmely JF, et al. Diagnostic accuracy of coronary in-stent restenosis using 64-slice computed tomography. J Am Coll Cardiol. 2007; 49:951-959.
12. Einstein AJ, Henzlova MJ, Rajagopalan S. Estimating risk of cancer associated with radiation exposure from 64-slice computed tomography coronary angiography. JAMA. 2007; 298(3):317-323.
13. Fine JJ, Hopkins CB, Ruff N, et al.  Comparison of accuracy of 64-slice cardiovascular computed tomography with coronary angiography in patients with suspected coronary artery disease.  Am J Cardiol. 2006; 97:173-174.
14. Francone M, Napoli A, Carbone I, et al. Noninvasive imaging of the coronary arteries using a 64-row multidetector CT scanner: initial clinical experience and radiation dose concerns. Radiol Med. 2007; 112:31–46.
15. Gallagher MJ, Ross MA, Raff GL, et al.  The diagnostic accuracy of 64-slice computed tomography coronary angiography compared with stress nuclear imaging in emergency department low risk chest pain patients.  Ann Emerg Med. 2007; 49:125-136.
16. Goldstein JA, Gallagher MJ, O'Neill WW, et al. A randomized controlled trial of multi-slice coronary computed tomography for evaluation of acute chest pain. J Am Coll Cardiol. 2007; 49(8):863-871.
17. Greenland P. Editorial: Who is a candidate for noninvasive coronary angiography? Ann Intern Med. 2006; 145:466-467.
18. Hamon M, Champ-Rigot L, Morello R, et al. Diagnostic accuracy of in-stent coronary restenosis detection with multislice spiral computed tomography: a meta-analysis. Eur Radiol. 2008; 18(2):217-225.
19. Hausleiter J, Meyer T, Hadamitzky M, Zankl M, et al. Non-invasive coronary computed tomographic angiography for patients with suspected coronary artery disease: the coronary angiography by computed tomography with the use of a submillimeter resolution (CACTUS) trial. Eur Heart J. 2007; 28(24):3034-3041.
20. Hausleiter J, Meyer T, Hermann F, et al. Estimated radiation dose associated with cardiac CT angiography. JAMA. 2009; 301(5):500-507.
21. Hoffmann U, Nagurney JT, Moselewski F, et al. Coronary multidetector computed tomography in the assessment of patients with acute chest pain. Circ. 2006; October 30:114(18).  Published on line at: http://www.circulationaha.org.  Accessed on January 14, 2009.
22. Hoffmann U, Ferencik M, Cury R, et al. Coronary CT angiography. J Nucl Med. 2006; 47:797-806.
23. Hong C, Chrysant GS, Woodard PK, et al.  Coronary artery stent patency assessed with in-stent contrast enhancement measured at multi-detector row CT angiography: initial experience.  Radiology. 2004; 233:286-291.
24. Husmann L, Schepis T, Scheffel H, et al. Comparison of diagnostic accuracy of 64-slice computed tomography coronary angiography in patients with low, intermediate, and high cardiovascular risk. Acad Radiol. 2008; 15(4):452-461.
25. Janne d'Othee B, Siebert U, Cury R, et al. A systematic review on diagnostic accuracy of CT-based detection of significant coronary artery disease. European J Radiol. 2008; 65(3):449-461.
26. Jones CM, Athanasiou T, Dunne N, et al. Multi-detector computed tomography in coronary artery bypass graft assessment: a meta-analysis. Ann Thorac Surg. 2007; 83(1):341-348.
27. Meijboom WB, Mollet NR, Van Mieghem AG, et al.  Preoperative computed tomography coronary angiography to detect significant coronary artery disease in patients referred for cardiac valve surgery.  JACC. 2006; 48(8):1658-1665.
28. Meijboom WB, Mollet NR, Van Mieghem CA, et al. 64-slice computed tomography coronary angiography in patients with non-ST elevation acute coronary syndrome. Heart. 2007; 93(11):1386-1392.
29. Meyer T, Martinoff S, Hadamitsky M, et al. Improved noninvasive assessment of coronary artery bypass grafts with 64-slice computed tomographic angiography in an unselected patient population. J Am Coll Cardiol. 2007; 49:946-950.
30. Miller JM, Rochitte CE, Dewey M, et at. Diagnostic performance of coronary angiography by 64-row CT. N Eng J Med. 2008; 359(22):2324-2336.
31. Mollet NR, Cademartiri F, Nieman K, et al.  Multislice spiral computed tomography coronary angiography in patients with stable angina pectoris.  J Amer Coll Cardiol. 2004; 43(12):2265-2270.
32. Mollet NR, Cademartiri F, van Mieghem CAG, et al.  High resolution spiral computed tomography coronary angiography in patients referred for diagnostic conventional coronary angiography.  Circ.  2005; 112:2318-2323.
33. Mollet NR, Cademartiri1 F, Mieghem CV, et al. Adjunctive value of CT coronary angiography in the diagnostic work-up of patients with typical angina pectoris. European Heart Journal. 2007; 28:1872–1878.
34. Mowatt G, Cook JA, Hillis GS, et al. 64-slice computed tomography angiography in the diagnosis and assessment of coronary artery disease: systematic review and meta-analysis. Heart. 2008a; 94(11):1386-1393.
35. Mowatt G, Cummins E, Waugh N, et al. Systematic review of the clinical effectiveness and cost-effectiveness of 64-slice or higher computed tomography angiography as an alternative to invasive coronary angiography in the investigation of coronary artery disease. Health Technol Assess. 2008b; 12(17):iii-iv, ix-143.
36. Nakanishi T, Ido K, Imazu M, et al.  Evaluation of coronary artery stenoses using electron-beam CT and multiplanar reformation.  J Comp Assist Tomogr. 1997; 21(1):121-127.
37. Nicol ED, Stirrup J, Reyes E, et al. Sixty-four-slice computed tomography coronary angiography compared with myocardial perfusion scintigraphy for the diagnosis of functionally significant coronary stenoses in patients with a low to intermediate likelihood of coronary artery disease. J Nucl Cardiol. 2008; 15(3):311-318.
38. Nieman K, Cademartiri F, Lemos PA, et al.  Reliable noninvasive coronary angiography with fast submillimeter multislice spiral computed tomography.  Circulation. 2002; 106:2051-2054.
39. Nikolaou K, Knez A, Rist C, et al.  Accuracy of 64-MDCT in the diagnosis of ischemic heart disease.  AJR. 2006; 187:111-117.
40. Ravipati G, Aronow WS, Lai H, et al. Comparison of sensitivity, specificity, positive predictive value, and negative predictive value of stress testing versus 64-multislice coronary computed tomography angiography in predicting obstructive coronary artery disease diagnosed by coronary angiography. Am J Cardiol. 2008; 101(6):774-775.
41. Redberg RF, Walsh J.  Pay now, benefits may follow – The case of cardiac computed tomographic angiography.  N Eng J Med. 2008; 359:2309-2310.
42. Rubinshtein R, Halon DA, Gaspar T, et al. Usefulness of 64-slice cardiac computed tomographic angiography for diagnosing acute coronary syndromes and predicting clinical outcome in emergency department patients with chest pain of uncertain origin. Circulation. 2007a; 115(13):1762-1768.
43. Rubinshtein R, Halon DA, Gaspar T, et al. Usefulness of 64-slice multidetector computed tomography in diagnostic triage of patients with chest pain and negative or nondiagnostic exercise treadmill test result. Am J Cardiol. 2007b; 99(7):925-929.
44. Rubinshtein R, Halon DA, Gaspar T, et al. Impact of 64-slice cardiac computed tomographic angiography on clinical decision-making in emergency department patients with chest pain of possible myocardial ischemic origin. Am J Cardiol. 2007c; 100(10):1522-1526.
45. Schlosser T, Mohrs OK, Magedanz A, et al. Noninvasive coronary angiography using 64-detector-row computed tomography in patients with a low to moderate pretest probability of significant coronary artery disease. Acta Radiol. 2007; 48(3):300-307.
46. Schmitt R, Froehner S, Brunn J, et al. Congenital anomalies of the coronary arteries: imaging with contrast-enhanced multidetector computed tomography.  Eur Radiol. 2005; 15:1110-1121.
47. Schuijf JD, Bax JJ, Jukema JW, Lamb HJ, et al.  Noninvasive evaluation of the coronary arteries with multislice computed tomography in hypertensive patients.  Hypertension. 2005; 45:1-6.
48. Shabestari AA, Abdi S, Akhlaghpoor S, et al. Diagnostic performance of 64-channel multislice computed tomography in assessment of significant coronary artery disease in symptomatic subjects. Am J Cardiol. 2007; 99(12):1656-1661.
49. Sun Z, Jiang W. Diagnostic value of multislice computed tomography angiography in coronary artery disease: A meta-analysis. Eur J Radiol. 2006; 60(2):279-286.
50. Vanhoenacker PK, Heijenbrok-Kal MH, Van Heste R, et al. Diagnostic performance of multidetector CT angiography for assessment of coronary artery disease: meta-analysis. Radiology. 2007; 244(2):419-428.
51. Vliegen HW, Doornbos J, de Roos A, et al.  Value of fast gradient echo magnetic resonance angiography as an adjunct to coronary arteriography in detecting and confirming the course of clinically significant coronary artery anomalies.  Am J Cardiol. 1997; 79:773-776. 

Government Agency, Medical Society, and Other Authoritative Publications:

1. AdminaStar Federal, Inc. Local Coverage Determination for: Cardiac Computed Tomography and Computed Tomography Coronary Angiography (LCD23276). Revised 09/15/2006.  Available at: http://www.empiremedicare.com/  Accessed on January 10, 2009.
2. AdminaStar Federal, Inc. Local Coverage Determination for: Magnetic Resonance Angiography (LCD7662). Revised 10/01/2006.  Available at: http://www.empiremedicare.com/  Accessed on January 10, 2009.
3. Agency for Healthcare Research and Quality (AHRQ). Non-Invasive Imaging for Coronary Artery Disease.  Health Technology Assessment Report conducted at the Duke Evidence-Based Practice Center. 2006 Oct. AHRQ. Rockville, MD. No. 290-02-0025. Available at:  http://www.cms.hhs.gov/determinationprocess/downloads/id34TA.pdf.  Accessed on January 10,  2009.
4. American College of Radiology (ACR) Practice Guideline for the Performance and Interpretation of CT Angiography (CTA).  10/01/2005. Revised 2006.  Available at: http://www.acr.org/EducationCenter/ACRFutureClassroom/ct_cardiac.aspx.  Accessed on January 30, 2009.
5. American College of Radiology (ACR) Practice Guideline for the Performance of Pediatric and Adult Body MRA. Effective October 2005. Amended 2006. Available at:     http://www.acr.org/SecondaryMainMenuCategories/quality_safety/guidelines/dx/cardio/body_mra.aspx.  Accessed on January 30, 2009.
6. Blue Cross Blue Shield Association. Contrast-enhanced Cardiac Computed Tomography Angiography in the Diagnosis of Coronary Artery Stenosis or for Evaluation of Acute Chest Pain.  TEC Assessment, 2006; 21(5).
7. Bluemke DA, Achenbach S, Budoff M, et al. Noninvasive Coronary Artery Imaging. Magnetic Resonance Angiography and Multidetector Computed Tomography Angiography. A Scientific Statement from the American Heart Association Committee on Cardiovascular Imaging and Intervention of the Council on Cardiovascular Radiology and Intervention, and the Councils on Clinical Cardiology and Cardiovascular Disease in the Young. Circulation 2008;118:586-606.
8. Budoff MJ,  Cohen MC, Garcia MJ, et al. ACCF/AHA Clinical Competence Statement on Cardiac Imaging with Computed Tomography and Magnetic Resonance. A Report of the American College of Cardiology Foundation/American Heart Association/American College of Physicians Task Force on Clinical Competence and Training. J Am Coll Cardiol. 2005; 46:383-402.
9. Budoff MJ, Achenbach S, Blumenthal RS, et al.  A Scientific Statement from the American Heart Association Committee on Cardiovascular Imaging and Intervention, Council on Cardiovascular Radiology and Intervention, and Committee on Cardiac Imaging, Council on Clinical Cardiology.  AHA Scientific Statement:  Assessment of Coronary Artery Disease by Cardiac Computed Tomography.  Circulation. 2006; 114:1761-1791.
10. Centers for Medicare and Medicaid Services. National Coverage Determination: Computerized Tomography. NCD #220.1. Effective November 22, 1985. Updated memo: 03/12/2008. Available at: http://www.cms.hhs.gov.   Accessed on January 14, 2009.
11. Centers for Medicare and Medicaid Services.  National Coverage Determination: Magnetic Resonance Angiography. NCD #220.3.  Effective July 1, 2003.  Available at: http://www.cms.hhs.gov.  Accessed on January 14, 2009.
12. Douglas PS, Hendel RC, Peterson ED et al.  ACCF/ASNC appropriateness criteria for single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI).  J Am Coll Cardiol 2005;46:1587-1605.
13. Hayes, Inc. Hayes Medical Technology Directory. Cardiac Magnetic Resonance Angiography. Lansdale, PA: Hayes, Inc; August 2005. Search updated September 9, 2008.
14. Hayes, Inc. Hayes Medical Technology Directory. Multislice Computed Tomography for Detection of Coronary Artery Disease. Lansdale, PA: Hayes, Inc; July 6, 2004. Reviewed, updated, and unbundled as a detection-specific report on July 19, 2007.  Search updated July 12, 2008.
15. Hendel RC, Patel MR, Kramer CM, et al. ACCF/ACR/SCCT/SCMR/ASNC/NASCI/SCAI/SIR Appropriateness Criteria for Cardiac Computed Tomography and Cardiac Magnetic Resonance Imaging: A report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group, American College of Radiology, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, American Society of Nuclear Cardiology, North American Society for Cardiac Imaging, Society for Cardiovascular Angiography and Interventions and Society of Interventional Radiology.  J Am Col Cardiol. 2006; 3:751-771
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CAD
Computed Tomography Angiography
Coronary Artery Disease
CTA
Virtual Angiography