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

Medically Necessary:

Contrast-enhanced coronary computed tomography angiography (CCTA), coronary magnetic resonance angiography (MRA), or cardiac magnetic resonance imaging (MRI) 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 individuals or as part of a preoperative evaluation; or
• Diagnosis of CAD, in individuals with acute or non-acute symptoms, or after a coronary intervention; or
• As a technique to evaluate cardiac function.

Cardiac magnetic resonance imaging (MRI) is considered investigational and not medically necessary for the following:

• Screening for CAD, either in asymptomatic individuals or as part of a preoperative evaluation, or
• Diagnosis of CAD, in individuals with acute or non-acute symptoms, or after a coronary artery intervention.

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 individuals with acute symptoms suggestive of CAD, and in individuals 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 an individual 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. This latter analysis has been considered more appropriate than per vessel or segment analysis, since treatment decisions are made on a per-person basis. It should also be noted that the majority of studies enrolled individuals 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 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 CCTA has a high negative predictive value in individuals without bypass grafts or stents. This high negative predictive value of CCTA forms the basis for the assertion that CCTA may be useful to identify those individuals who would not benefit from coronary angiography. In contrast, the positive predictive value of CCTA may not be clinically relevant in those at high risk for CAD based on symptoms, risk factors or other imaging techniques. These individuals would most likely benefit from invasive angiography, since the likelihood is high that interventional treatment at the time of angiography would be necessary.

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 participants 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-person 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 individuals to identify those with and without CAD. However, the negative predictive value of 83% is lower than other reports (Cademartiri, 2007; Hausleiter, 2007; Hussman, 2008; Schlosser, 2007), and the authors state that, on this basis, CCTA cannot replace invasive coronary artery angiography in this population of symptomatic individuals. 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 individuals 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 person, considering both 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 individuals 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 individuals with an intermediate risk of CAD who have negative results from CCTA. For example, registry reports can provide important information regarding whether these individuals undergo angiography. Randomized trials could compare the efficacy of CCTA vs. myocardial perfusion imaging as the initial study in individuals 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 14 mSv 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, CCTA 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 individual 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 ACCURACY Trial (Assessment by Coronary Computed Tomographic Angiography of Individuals Undergoing Invasive Coronary Angiography) evaluated CCTA results from 230 of 245 individuals experiencing typical or atypical chest pain but without known CAD. This prospective study evaluated subjects with chest pain at 16 sites who were clinically referred for invasive coronary angiography (ICA). CCTAs were scored by consensus of three independent blinded readers. The ICAs were evaluated for coronary stenosis based on quantitative coronary angiography (QCA). A total of 230 subjects underwent both CCTA and ICA (59.1% male; mean age: 57 ± 10 years). The sensitivity, specificity, and positive and negative predictive values to detect greater than or equal to 50% or greater than or equal to 70% stenosis were 95%, 83%, 64%, and 99%, respectively, and 94%, 83%, 48%, 99%, respectively. No differences in sensitivity and specificity were noted for non-obese compared with obese subjects or for heart rates less than or equal to 65 beats/min compared with greater than 65 beats/min, whereas calcium scores greater than 400 reduced specificity significantly. Pretest disease probability, radiation dose, incidental noncardiac finding prevalence and follow-up were not reported (Budoff, 2008b).

In 2010 Hamirani and colleagues compared the accuracy of nuclear stress imaging to CCTA in 122 symptomatic individuals with cardiac catheterization. These individuals underwent MPI and CCTA evaluations within 6 months. The study was not a head-to-head comparison of MPI and CCTA but rather a comparison of diagnostic accuracy of each modality to cardiac catheterization. The comparability of the techniques is in question since CCTA provides anatomic information whereas MPI has additional functional and prognostic value. The prevalence of greater than 50% stenosis on cardiac catheterization was 74.6%, CCTA was 80.3%. The prevalence of greater than 70% stenosis on cardiac catheterization was 63.9%, CCTA was 62.3%. On MPI, 68 individuals were found to have perfusion defects. Sensitivity, specificity and positive and negative predictive values in those with greater than 50% lesions for CCTA were 98.9%, 74.2%, 91.8%, and 95.8%, respectively. For MPI, the values were 56%, 38.7%, 72.9%, and 23% respectively. Sensitivity, specificity and positive and negative predictive values in those with greater than 70% lesions for CCTA were 89.7%, 86.4%, 92.1%, and 82.6% respectively. For MPI, the values were 57.7%, 43.2%, 64.3%, and 36.5%, respectively. The study is limited by its retrospective and observational design. The participants in the study also had a higher prevalence of CAD (53%), which might have affected the specificity and negative predictive value of the study. The authors also noted that CCTA is limited by artifacts caused by high coronary artery calcium scores, coronary motion caused by fast heart rates and by breathing artifacts.

Additional studies and meta-analyses of 64-slice MDCT scanning have examined the diagnostic accuracy of CCTA in comparison to conventional ICA (Meijer, 2008; Mowatt, 2008a; Stein, 2008). In these and other prior studies of CCTA vs. ICA, high disease prevalence has a positive impact on the accuracy of the CCTA test results. The test accuracy of CCTA among populations with lower disease prevalence is of interest in the further assessment of clinical utility for CCTA in comparison to ICA results. In addition, 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.

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 2010, the American College of Cardiology Foundation Appropriate Use Criteria Task Force published appropriate use criteria for cardiac computed tomography (Taylor, 2010). The task force used a process which combines evidence-based medicine and practice experience by engaging a technical panel in a modified Delphi exercise. It should be noted that the technical requirements of a Rand Modified Delphi approach (Gordon, 2009) were not strictly adhered to in this report and resulted in obtaining a consensus of individuals on the panel rather than an evidence-based approach. In addition, this ACCF publication did not address concerns regarding the limited data about the harms of radiation from CCTA or the consequences of falsely positive CCTA prompting additional unnecessary interventions.

A 2011 study by Chow and colleagues studied the accuracy of CCTA for CAD across multiple centers. There was variability across the multiple centers with a sensitivity, specificity, positive predictive value, and negative predictive value ranging from 50.0% to 93.2%, 92.0% to 100%, 84.6% to 100%, and 42.9% to 94.7%, respectively. The authors concluded there needs to be an understanding of what is causing the variability amongst the facilities before there can be a universal adoption of this diagnostic test.

McEvoy and colleagues (2011) reported on 1000 asymptomatic individuals who had already had CCTA previously and followed them for 18 months. Individuals were assessed at 90 days and then again at 18 months for medication use, secondary test referrals, revascularizations and cardiovascular events. Comparing the CCTA group to a matched control group (who had not had a previous CCTA), the authors reported that 785 individuals had a reported normal CCTA with 215 individuals with "positive CCTA" results. There was no difference in the use of statins between the CCTA group and the control group at baseline however statins were prescribed more often to those with a positive CCTA result compared with the control group. Similar findings were noted with the use of aspirin. Those individuals who had positive CCTA results were more likely to be referred for secondary tests when compared with the control group. Revascularization was more prevalent in the CCTA group as opposed to the control group. At 90 days, 12 individuals had percutaneous coronary intervention, 1 individual had coronary artery bypass graft surgery in the CCTA group whereas 1 individual in the control group had percutaneous coronary intervention. There were no differences in revascularizations at 18 months. In the first 90 days there were no cardiac events for either group (CCTA and control). At 18 months there was 1 admission for unstable angina in the CCTA group and 1 unspecified cardiac death in the control group. At 18 months, screening CCTA was associated with increased invasive testing, but no difference in events and should not be considered a justifiable test at this time.

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 individuals for invasive coronary artery angiogram, particularly those individuals considered to be at intermediate risk of CAD. These studies, and resultant clinical recommendations and appropriate use 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 individuals with suspected CAD, and how CCTA will ultimately improve 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 individuals 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 approximately 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, seven case series enrolling a total of 161 participants 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.

A writing group deployed by the Working Group Nuclear Cardiology and Cardiac CT of the European Society of Cardiology and the European Council of Nuclear Cardiology published a report on Cardiac Computed Tomography in which the following is noted:

The robust visualization and classification of anomalous coronary arteries make CTA a first-choice imaging modality for the investigation of known or suspected coronary artery anomalies. Radiation dose must be considered often in the young patients, and measures to keep dose as low as possible must be employed (Schroeder, 2008).

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-person 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 six studies including 109 participants 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.

Cardiac MRI
The 2006 American College of Cardiology Appropriateness Criteria (Hendel, 2006) rates cardiac MRI as an appropriate indication for the evaluation of suspected coronary anomalies.

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 non-invasive alternative to invasive coronary angiography, particularly in individuals with an intermediate risk of significant coronary artery disease (CAD). 

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. 

MRI is a non-invasive imaging modality that uses magnetic and radiofrequency fields to image body tissue producing very detailed, cross-sectional pictures of the body.

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.

Magnetic resonance imaging (MRI): A noninvasive diagnostic technique that produces computerized images of internal body structures and tissues.

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 or for all other diagnoses not listed, or when the code describes a procedure indicated in the Position Statement section as investigational and not medically necessary.

When services may also be Medically Necessary when criteria are met:

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

Future ICD-10 coding (effective 10/01/2013)
A draft of ICD-10 Coding related to this document, as it might look today, is available for reference and comments at: Appendix 1: Future ICD-10 coding

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(3):402-406.
2. Brodoefel H, Burgstahler C, Tsiflikas I, et al. Dual-source CT: effect of heart rate, heart rate variability, and calcification on image quality and diagnostic accuracy. Radiology. 2008; 247(2):346-355.
3. 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.
4. Budoff MJ, Dowe D, Jollis JG, et al. Diagnostic performance of 64-multidetector row coronary computed tomographic angiography for evaluation of coronary artery stenosis in individuals without known coronary artery disease: results from the prospective multicenter ACCURACY (Assessment by Coronary Computed Tomographic Angiography of Individuals Undergoing Invasive Coronary Angiography) trial. J Am Coll Cardiol. 2008b; 52(21):1724-1732.
5. Budoff MJ, Gopal A, Gul KM, et al. Prevalence of obstructive coronary artery disease in an outpatient cardiac CT angiography environment. International J Cardiol. 2008a; 129(1):32-36.
6. Cademartiri F, La GL, Palumbo A, et al. Computed tomography coronary angiography vs. stress ECG in patients with stable angina. Radiol Med. 2009; 114(4):513-523.
7. Cademartiri F, Maffei E, Palumbo A, et al. Diagnostic accuracy of 64-slice computed tomography coronary angiography in patients with low-to-intermediate risk. Radiol Med. 2007; 112(7):969-981.
8. Carrabba N, Schuijf JD, de Graaf FR, et al. Diagnostic accuracy of 64-slice computed tomography coronary angiography for the detection of in-stent restenosis: a meta-analysis. J Nucl Cardiol. 2010; 17(3):470-478.
9. Chow BJ, Freeman MR, Bowen JM, et al. Ontario multidetector computed tomographic coronary angiography study: field evaluation of diagnostic accuracy. Arch Intern Med. 2011; 171(11):1021-1029.
10. Datta J, White CS, Gilkeson RC, et al. Anomalous coronary arteries in adults: depiction at multi-detector row CT angiography. Radiology. 2005; 235(3):812-818.
11. 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.
12. 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(9):951-959.
13. 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(5):564–571.
14. 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.
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(2):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. Greenberg-Wolff I, Uliel L, Goitein O, et al. Extra-cardiac findings on coronary computed tomography scanning. Isr Med Assoc J. 2008; 10(11):806-808.
18. Hamirani YS, Isma'eel H, Larijani V, et al. The diagnostic accuracy of 64-detector cardiac computed tomography compared with stress nuclear imaging in patients undergoing invasive cardiac catheterization. J Comput Assist Tomogr. 2010; 34(5):645-651.
19. Hamon M, Biondi-Zoccai GG, Malagutti P, et al. Diagnostic performance of multislice spiral computed tomography of coronary arteries as compared with conventional invasive coronary angiography: a meta-analysis. J Am Coll Cardiol. 2006; 48(9):1896-1910.
20. 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.
21. 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.
22. Hausleiter J, Meyer T, Hermann F, et al. Estimated radiation dose associated with cardiac CT angiography. JAMA. 2009; 301(5):500-507.
23. Hoffmann U, Bamberg F, Chae CU, et al. Coronary computed tomography angiography for early triage of patients with acute chest pain: the ROMICAT (Rule Out Myocardial Infarction using Computer Assisted Tomography) trial. J Am Coll Cardiol. 2009; 53(18):1642-1650.
24. 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(1):286-291.
25. Hurwitz LM, Reiman RE, Yoshizumi TT, et al. Radiation dose from contemporary cardiothoracic multidetector CT protocols with an anthropomorphic female phantom: implications for cancer induction. Radiology. 2007; 245(3):742-750.
26. 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.
27. Jacobs PC, Mali WP, Grobbee DE, et al. Prevalence of incidental findings in computed tomographic screening of the chest: a systematic review. J Comput Assist Tomogr. 2008; 32(2):214-221.
28. 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.
29. Marano R, De CF, Floriani I, et al. Italian multicenter, prospective study to evaluate the negative predictive value of 16- and 64-slice MDCT imaging in patients scheduled for coronary angiography (NIMISCAD-Non Invasive Multicenter Italian Study for Coronary Artery Disease). Eur Radiol. 2009; 19(5):1114-1123.
30. McEvoy JW, Blaha MJ, Nasir K, et al. Impact of coronary computed tomographic angiography results on patient and physician behavior in a low-risk population. Arch Intern Med. 2011; 171(14):1260-1268.
31. Meijboom WB, Meijs MF, Schuijf JD, et al. Diagnostic accuracy of 64-slice computed tomography coronary angiography: a prospective, multicenter, multivendor study. J Am Coll Cardiol. 2008; 52(25):2135-2144.
32. 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.
33. 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.
34. Meijboom WB, van Mieghem CA, Mollet NR, et al. 64-slice computed tomography coronary angiography in patients with high, intermediate, or low pretest probability of significant coronary artery disease. J Am Coll Cardiol. 2007; 50(15):1469-1475.
35. Meijer AB, O YL, Geleijns J, et al. Meta-analysis of 40- and 64-MDCT angiography for assessing coronary artery stenosis. AJR Am J Roentgenol. 2008; 191(6):1667-1675.
36. 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.
37. 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(15):1872–1878.
38. 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.
39. Ostrom MP, Gopal A, Ahmadi N, et al. Mortality incidence and the severity of coronary atherosclerosis assessed by computed tomography angiography. J Am Coll Cardiol. 2008; 52(16):1335-1343.
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(22):2309-2310.
42. 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.
43. 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.
44. 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.
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(6):1110-1121.
47. Stein PD, Yaekoub AY, Matta F, et al. 64-slice CT for diagnosis of coronary artery disease: a systematic review. Am J Med. 2008; 121(8):715-725.
48. Sun Z, Davidson R, Lin CH. Multi-detector row CT angiography in the assessment of coronary in-stent restenosis: a systematic review. Eur J Radiol. 2009; 69(3):489-495.
49. Wykrzykowska JJ, Arbab-Zadeh A, Godoy G, et al. Assessment of in-stent restenosis using 64-MDCT: analysis of the CORE-64 Multicenter International Trial. AJR Am J Roentgenol. 2010; 194(1):85-92. 

Government Agency, Medical Society, and Other Authoritative Publications:

1. Abbara S, Arbab-Zadeh B, Callister TQ, et al. SCCT guidelines for performance of coronary computed tomographic angiography: A report of the Society of Cardiovascular Computed Tomography Guidelines Committee. J Cardiovas Comput Tomog. 2009; 3(3):190-204.
2. Agency for Healthcare Research and Quality. Non-Invasive Imaging for Coronary Artery Disease. Health Technology Assessment Report conducted at the Duke Evidence-Based Practice Center. 2006 Oct. No. 290-02-0025. Available at: http://www.cms.hhs.gov/determinationprocess/downloads/id34TA.pdf. Accessed on September 27, 2011.
3. American College of Radiology. ACR Appropriateness Criteria^®. Available at: http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria.aspx. Accessed on September 30, 2011.
   • Chest Pain Suggestive of Acute Coronary Syndrome (2010)
   • Chronic Chest Pain — High Probability of Coronary Artery Disease (2010)
4. 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).
5. 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(5):586-606.
6. Budoff MJ, Achenbach S, Blumenthal RS, et al. Assessment of coronary artery disease by cardiac computed tomography: 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. Circulation. 2006; 114(16):1761-1791.
7. Gerber TC, Carr JJ, Arai AE, et al. Ionizing radiation in cardiac imaging: a science advisory from the American Heart Association Committee on Cardiac Imaging of the Council on Clinical Cardiology and Committee on Cardiovascular Imaging and Intervention of the Council on Cardiovascular Radiology and Intervention. Circulation. 2009; 119(7):1056-1065.
8. Gordon, TJ. Chapter 4: The Delphi Method. In: Glenn JC, Gordon TJ, Editors. Futures Research Methodology V3.0. The Millennium Project. 2009. Available at: www.millennium-project.org/FRMv3_0/04-Delphi.pdf. Accessed on September 27, 2011.
9. Hendel RC, Berman DS, Di Carli MF, et al. ACCF/ASNC/ACR/AHA/ASE/SCCT/SCMR/SNM 2009 appropriate use criteria for cardiac radionuclide imaging: a report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, the American Society of Nuclear Cardiology, the American College of Radiology, the American Heart Association, the American Society of Echocardiography, the Society of Cardiovascular Computed Tomography, the Society for Cardiovascular Magnetic Resonance, and the Society of Nuclear Medicine. J Am Coll Cardiol. 2009; 53(23):2201-2229.
10. Hendel RC, Patel MR, Kramer CM, et al. ACCF/ACR/SCCT/SCMR/ASNC/NASCI/SCAI/SIR 2006 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 Coll Cardiol. 2006; 48(7):1475-1497.
11. Institute for Clinical and Economic Review (ICER). Coronary computed tomographic angiography for detection of coronary artery disease. Final appraisal document. January 9, 2009. Available at: http://www.icer-review.org/index.php/ccta.html. Accessed on October 3, 2011.
12. Institute for Clinical Systems Improvement. Health Care Guideline: Diagnosis and Treatment of Chest Pain and Acute Coronary Syndrome. Sixth Edition, October 2010. Available at: http://www.icsi.org/acs_acute_coronary_syndrome/acute_coronary_syndrome_and_chest_pain__diagnosis_and_treatment_of_2.html. Accessed on September 26, 2011.
13. Medical Advisory Secretariat. Multidetector computed tomography for coronary artery disease screening in asymptomatic populations: an evidence-based analysis. Ontario Health Technology Assessment Series 2007;7(3).
14. Schroeder S, Achenbach S, Bengel F, Burgstahler C, Working Group Nuclear Cardiology and Cardiac CT, European Society of Cardiology, European Council of Nuclear Cardiology, et al. Cardiac computed tomography: indications, applications, limitations, and training requirements: report of a Writing Group deployed by the Working Group Nuclear Cardiology and Cardiac CT of the European Society of Cardiology and the European Council of Nuclear Cardiology. Eur Heart J. 2008; 29(4):531-556.
15. Stillman AE, Oudkerk M, Ackerman M, et al. Use of multidetector computed tomography for the assessment of acute chest pain: a consensus statement of the North American Society of Cardiac Imaging and the European Society of Cardiac Radiology. Eur Radiol. 2007; 17(8):2196-2207.
16. Taylor AJ, Cerqueira M, Hodgson JM, et al. ACCF/SCCT/ACR/AHA/ASE/ASNC/SCAI/SCMR 2010 Appropriate use criteria for cardiac computed tomography. A Report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, the Society of Cardiovascular Computed Tomography, the American College of Radiology, the American Heart Association, the American Society of Echocardiography, the American Society of Nuclear Cardiology, the Society for Cardiovascular Angiography and Interventions, and the Society for Cardiovascular Magnetic Resonance. Circulation. 2010; 122(21):e525-555. Available at: http://circ.ahajournals.org/content/122/21/e525.full.pdf. Accessed on September 29, 2011.
17. Walsh J. California Technology Assessment Forum. Computed tomographic angiography in the diagnosis of coronary artery stenosis and for the evaluation of acute chest pain. A Technology Assessment. 2007. Available at: http://www.ctaf.org/content/assessment/detail/768. Accessed on September 26, 2011.

1. National Institutes of Health (NIH). National Heart, Lung, and Blood Institute. Available at: http://www.nhlbi.nih.gov/. Accessed on September 26, 2011.

CAD
Computed Tomography Angiography
Coronary Artery Disease
CTA
Magnetic Resonance Angiography
Magnetic Resonance Imaging
MRA
MRI
Virtual Angiography