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Right arrow Coronary disease

Ann Thorac Surg 2007;83:341-348
© 2007 The Society of Thoracic Surgeons

Reviews

Multi-Detector Computed Tomography in Coronary Artery Bypass Graft Assessment: A Meta-Analysis

Catherine M. Jones, MBBS, BSa, Thanos Athanasiou, MD, FECTSb,*, Nicola Dunne, MBBSc, Joanne Kirby, MbChBd, Omer Aziz, MRCS, BSb, Ahmed Haq, MBBSb, Christopher Rao, BSb, Vasilis Constantinides, MBBS, BSb, Sanjay Purkayastha, MRCS, BSb, Ara Darzi, FRCS, KBEb

a Department of Radiology, City Hospital, Birmingham, United Kingdom
b Department of Biosurgery and Surgical Technology & Department of Cardiothoracic Surgery, Imperial College, St Mary’s Hospital, London, United Kingdom
c Royal Berkshire and Battle NHS Trust, Reading, United Kingdom
d Birmingham Heartlands Hospital, Birmingham, United Kingdom

* Address correspondence to Dr Athanasiou, Imperial College, Department of Cardiothoracic Surgery, 111 Gowan Ave, Fulham, London, SW6 6RQ United Kingdom (Email: tathan5253{at}aol.com).


   Abstract
Top
 Abstract
Introduction
 Patients and Methods
 Results
 Comment
 References
 
Multi-detector computed tomography (MDCT) has become an alternative to coronary angiography in diagnosis of graft occlusion and stenosis after coronary artery bypass. A literature search was performed for studies comparing angiography to 8-slice, 16-slice, and 64-slice MDCT in the assessment of coronary grafts. In assessing occlusion, 14 studies produced pooled sensitivity of 97.6%, specificity of 98.5%, diagnostic odds ratio of 934.2, area under the curve of 0.996, and Q* of 0.977. Ninety-six percent of all grafts were visualized for occlusion assessment. Beta blockers, symptomatic status, and postoperative period did not significantly affect diagnostic performance. Stenosis assessment produced sensitivity of 88.7% and specificity of 97.4%. Eighty-eight percent of patent grafts could be assessed for stenosis. The diagnostic accuracy of MDCT approaches angiography for diagnosing graft occlusion and stenosis in patients with venous and arterial coronary bypass grafts. Our findings show that cardiac surgeons will need to interpret MDCT images of both native and grafted vessels soon in preparation for primary or re-do coronary bypass grafting procedures.


   Introduction
Top
 Abstract
 Introduction
Patients and Methods
 Results
 Comment
 References
 
The aim of coronary artery bypass grafting (CABG) is to replace occluded or stenosed coronary arteries with patent venous or arterial conduits. Long-term sequelae after CABG include native coronary artery disease progression and de novo atherosclerosis in grafts, resulting in recurrent ischemic symptoms and mortality [1]. Although the risk of ischemic symptoms after CABG ranges from 4% to 9% every year after surgery [1, 2], only 25% of venous grafts are free of significant disease by 10 years [3].

In patients with recurrent ischemic symptoms, coronary angiography is usually performed by cardiologists or radiologists to evaluate suspected native artery or graft stenosis, but its use is selective due to its complications profile. These complications include trauma to the arterial cannulation site with pseudoaneurysm formation (1.2%), cardiac arrhythmia (1%), stroke (0.3%), myocardial infarction (0.2%), angina (0.2%), coronary artery or graft dissection, and renal failure secondary to embolic disease or contrast [4].

There are numerous studies published on MDCT assessment of coronary graft patency and stenosis. Its accuracy compared with angiography has been reviewed [5]; however this review does not incorporate the literature on 16-slice and 64-slice MDCT, which is now standard in most North American centers. No analysis with respect to graft stenosis accuracy, symptomatic status, assessable grafts, or beta blocker administration has been performed.

This aim of this meta-analysis is to determine the diagnostic accuracy of 8-slice, 16-slice, and 64-slice MDCT versus angiography in the diagnosis of graft occlusion and stenosis. The effects of beta blocker administration, symptomatic status, and postoperative period are also analyzed. The increasingly direct diagnostic role of the cardiac surgeon is discussed, in the context of current and emerging MDCT capabilities, which provides a noninvasive alternative to angiography.


   Patients and Methods
Top
 Abstract
 Introduction
 Patients and Methods
Results
 Comment
 References
 
Study Selection
A search of MEDLINE for studies assessing coronary graft patency or stenosis was made comparing angiography to MDCT. The following MeSH headings were used: tomography x-ray-computed, coronary artery bypass, and coronary angiography, and the search was limited to human subjects. Each abstract was reviewed by two of the authors (CMJ, ND) for eligibility into the review. The "related articles" function in PubMED broadened the search. Unpublished, but accepted work was included as possible. No language restrictions were made. When patient overlap was reported by an institution, either the higher quality or the more recent publication was included as decided by two of the authors (CMJ, TA).

Included studies compared CABG patency or stenosis, or both, on MDCT versus angiography. Adequate information to calculate sensitivity and specificity for each outcome of interest was required. Studies in which the use of MDCT was unconfirmed, performed as preoperative workup, or performed on patients with conduit stenting or angioplasty were excluded.

Data Extraction
Two reviewers (CMJ, JK) independently extracted the following from each study: first author, publication year, institution, study population characteristics, study design, definitions of graft occlusion and stenosis, and beta blocker administration. The period of time between surgery and MDCT was early if the interval was less than 30 days, late if more than 30 days, and mixed if there were patients in both postoperative periods. The use of quantitative coronary assessment was noted, as this reduces the overestimation of luminal narrowing associated with visual assessment.

Outcomes of Interest and Definitions
The primary outcomes of interest were MDCT accuracy compared with angiography in diagnosis of graft occlusion and significant stenosis after CABG. Each graft was analyzed separately. For sequential grafts, in which the comparative study has considered each distal anastomosis as a separate conduit in its analysis, this was repeated in the analysis. Subgroup analysis of arterial and venous grafts was performed. The effects of postoperative period (early or late), symptomatic status, and beta blocker administration were examined using meta-regression. The number of grafts unable to be assessed was noted. Inability to assess a graft is the inadequate visualization to exclude or confirm a lesion.

Quality Assessment
The quality of the study was assessed using the quality assessment of diagnostic accuracy studies (QUADAS) tool [6] consisting of 14 items indicating differences in quality among studies included in diagnostic reviews.

Statistical Analysis
Angiography was the reference standard. For diseased grafts on angiography, MDCT results were true positive if positive or false negative if negative. For grafts without disease on angiography, MDCT results were true negative if negative or false positive if positive.

Pooled sensitivity, specificity, positive predictive value, and negative predictive value with 95% confidence intervals were estimated. Fixed effects modeling produced conservative estimates. A diagnostic odds ratio significantly greater than 1 indicates better than random diagnostic discrimination of MDCT.

Summary receiver operating characteristic analysis estimated diagnostic accuracy using area under the curve, diagnostic odds ratio, and Q* values [7]. The area under the curve is a value between 0 and 1 indicating area under the summary receiver operating characteristic curve, with diagnostic performance improving as area under the curve approaches 1. Q* also summarizes diagnostic performance with a value between 0 and 1, with diagnostic performance improving as quantitative coronary analysis approaches 1.

To assess the effect of study quality on diagnostic odds ratio, studies were allocated a "yes" or "not yes" value for each quality assessment of diagnostic accuracy studies (QUADAS) item. Univariate analysis for each item was performed [8]. Items associated with log diagnostic odds ratio (p < 0.10) were included in regression until a multivariate model was achieved (p < 0.05). The effect of each item was expressed as relative diagnostic odds ratio with 95% confidence intervals, indicating its impact on diagnostic accuracy [8, 9]. Relative diagnostic odds ratio greater than 1 shows a greater diagnostic odds ratio, and therefore greater accuracy when the item achieves "yes" compared to "not yes." Meta-regression tested the influence of beta blockers, symptomatic status, and postoperative period on the diagnostic odds ratio for occlusion and stenosis.

Analysis was conducted using the SPSS Version 11.0 for Windows (SPSS Inc, Chicago, IL) and Meta-Test Software Version 0.9 (Joseph Lau) according to guidelines for meta-analyses evaluating diagnostic tests [10].


   Results
Top
 Abstract
 Introduction
 Patients and Methods
 Results
Comment
 References
 
Studies Included
The literature search identified 168 articles using the MeSH headings, related articles function, and reference review. Further studies were included as citations became available. Fifteen studies [11–25] were selected for inclusion (Table 1) using retrospective electrocardiogram gating to optimize image quality, although the number and timing of reconstructions varied. Information on scan time, heart rate, and patient age was incompletely present. Tube modulation was used in later studies. Quantitative coronary assessment was used in angiography protocols in 12 studies rather than visual assessment, which tends to overestimate the degree of luminal narrowing. All but three studies [11, 17, 24] reported results based on multiple readers, reporting in consensus [13, 14, 16, 19, 20, 25] or independently [12, 15, 18].


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  		Table 1. Characteristics of the Included Multi-Detector Computed Tomography Studies
 
Results for Diagnostic Accuracy: Occlusion
Thirteen studies of 1,791 grafts were included (Table 2). One study [22] provided results on a per segment basis and was excluded from the analysis. The calculated positive predictive value was 93.6% (95% confidence interval, 90.5% to 96.0%) and the negative predictive value was 99.4% (95% confidence interval, 98.9% to 99.8%) for diagnosis of occlusion. The summary receiver operating characteristic curve (for occlusion) for the 13 studies is shown in Figure 1. Subgroup analysis of arterial and venous grafts was performed (Table 2). Beta blockers, ischemic symptoms, and postoperative period did not significantly affect accuracy (Table 3).


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  		Table 2. Pooled Sensitivity and Specificity Results
 

Figure 1
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  		Fig 1. Summary receiver operating characteristic (SROC) curve of MDCT for graft occlusion. (AUC = area under the curve; SE = standard error).

 

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  		Table 3. Results for Beta Blockers, Symptomatic Status, Postoperative Period and QUADAS Items With p < 0.10 on Univariate Analysis
 
Of 1,861 grafts, 1,791 (96%) were adequately visualized. The 70 inadequately visualized grafts suffered from respiratory motion [13, 18], clip artifact [13, 15, 24], ectopic beats [13, 18], or other reasons for poor visualization. Excluding these 70 grafts, there were 8 false negative results [11, 13, 17, 21] and 22 false positive results [12, 13, 21, 23, 24]. Reasons for false positive results included one string sign [23] due to competitive flow from a native artery, vessel diameter under 1.5 mm [24], and a filiform stenosis of a left internal mammary artery ostium [12].

Results for Diagnostic Accuracy: Stenosis
Eight studies, including 878 non-occluded grafts, were available for stenosis analysis (Table 2). Calculated positive predictive value is 77.8% (95% confidence interval, 67.2% to 86.3%) and negative predictive value is 98.8% (95% confidence interval, 97.7% to 99.5%). Figure 2 shows the summary receiver operating characteristic curve for diagnosis of stenosis. Subgroup analysis of available data on arterial and venous grafts was performed (Table 2).


Figure 2
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  		Fig 2. Summary receiver operating characteristic (SROC) curve of MDCT for graft stenosis. (AUC = area under the curve; SE = standard error).

 
Six of the eight studies [12, 15, 18, 20, 24, 25] gave beta blockers prior to MDCT. There was no significant effect of beta blocker administration, ischemic symptoms, or postoperative period on diagnostic performance (Table 3).

Of 878 possible non-occluded grafts for assessment of stenosis, 777 (88%) were adequately visualized on MDCT. Inadequate visualization was due to poor contrast opacification [20], motion artifact [12, 20], metallic clips [12, 24], and small vessel diameter [20]. Nine false negative results were due to visual underestimation of stenosis grade [12], insufficient contrast opacification [18], motion artifact [12], small vessel diameter [23], and a semi-calcified plaque mimicking an opacified lumen [25]. Nineteen false positive results were attributed to overestimation of stenosis grade [12, 23, 24], poor opacification of small vessels [25], and metallic clips [23]. Reporting of reasons for inaccurate results was variable across the studies.

Quality Analysis Results
Seven studies reported that the MDCT readers had the same clinical details as would be available in practice (ie, item 12 in quality assessment of diagnostic accuracy studies [QUADAS]) (Table 3). Thirteen studies reported blinding to angiography results (item 10).

In occlusion analysis, item 14 (explanation given for study withdrawals) led to significantly improved diagnostic results (Table 3). Items 1 and 2 (spectrum of patients included in study; explanation of selection criteria) approached significance. In stenosis analysis, only item 12 (availability of clinical data) approached statistical significance (p = 0.08).


   Comment
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
References
 
This analysis shows that MDCT is comparable with angiography for coronary artery graft occlusion and stenosis assessment, and that a noninvasive, low morbidity investigation can be used to diagnose graft disease post CABG. Both 16-slice and 64-slice MDCT offer not only low morbidity surveillance of coronary grafts, but also earlier investigation of asymptomatic patients with potential graft disease, and earlier endoluminal or open surgical intervention.

Image quality is better in patients with heart rates of less than 65 beats per minute [26, 27], which has led some groups to give intravenous beta blockers before MDCT. This is not without risk, especially in patients with chronic obstructive pulmonary disease [15], and there is no significant diagnostic benefit. However, in this review the rate of grafts able to be assessed was 96% for occlusion, and 88% for stenosis, showing that current protocols are proving effective in visualizing the vast majority of grafts.

Asymptomatic patients are not routinely investigated for graft patency due to the risks and cost of angiography. Detecting a stenosed or occluded graft in an asymptomatic patient may not prompt invasive reintervention, but subsequent symptoms and investigations may be interpreted with the benefit of the MDCT results. Increasing graft stenosis on serial MDCT scans may prompt percutaneous stenting or angioplasty before graft occlusion occurs. The high risk of coronary graft occlusion may mean benefit from MDCT graft surveillance. The absence of ischemic symptoms does not have a significant impact on diagnostic accuracy of MDCT. Most importantly, cardiac surgeons will need to know how to interpret MDCT images as the number of coronary MDCT scans is rapidly increasing. The traditional methods of assessing artery and graft stenosis are being challenged by MDCT, which affects surgeons’ decision-making for bypass grafting.

The excellent negative predictive value of MDCT in diagnosing both occlusion and stenosis indicates that significant graft disease is practically excluded by a negative MDCT, avoiding unnecessary angiography. The obvious drawback to MDCT is its inability to facilitate immediate intervention (such as angioplasty or stenting) in patients with positive findings. However, subsequent invasive intervention may then occur only in patients for whom it is indicated.

The thinner slices of 16-slice and 64-slice MDCT mean better image resolution, so much so that 3-dimensional reconstructions show consistent detail in every plane, aiding diagnosis. High-density material such as surgical clips, coronary artery stents, and coronary wall calcification may cause image degradation. For patients with coronary stents in situ, images are at higher risk of degradation due to the small diameter of the stent lumen. Stent patency is still assessable by looking at contrast in the vessel at points "pre" and "post" stenting. However, the problem with non-assessable stents remains one to be fully overcome. Multi-detector computed tomography can also display both the vessel wall and lumen, and therefore distinguish radial artery spasm from intimal hyperplasia [28].

The increased radiation of MDCT (6.7–13 mSv [29] compared with angiography [2.1 mSv]) makes routine use controversial. Tube current modulation has reduced the radiation dose [30], and future dose-reducing devices should further decrease dose. However, MDCT coronary artery screening is not recommended, because of dose considerations and the risk of unnecessary angiography. In addition to this, the need for intravenous contrast agents has the risks of anaphylaxis contrast induced nephropathy, although these risks are also present in invasive angiography.

Retrospective electrocardiogram gating is performed during diastole to take advantage of the reduced motion of the coronary arteries and grafts. Individualized reconstructions help visualization of both native and grafted vessels [31, 32]. Left circumflex artery grafts may blend into adjacent veins and left atrium; therefore visualization is more difficult [33], whereas cardiac motion artifact is greater for grafts on the lateral and inferior walls. A disadvantage of retrospective electrocardiogram gating is that the patients with arrhythmias are prone to image degradation.

Factors making CABG conduits easier to evaluate compared with native arteries include their larger diameter [15, 20], lesser calcification [20], and relatively lower mobility [15, 20]. Multi-detector computed tomography can play an important preoperative role in redo CABG by offering the cardiac surgeon the chance to preoperatively plan not only the vessels to be grafted, but also the course of the internal mammary graft, which may be avoided during sternotomy.

False positive findings may be caused by competitive flow in native arteries, distal anastomotic artifact, and delay in contrast arrival in internal mammary grafts. False negative findings may be due to presence of collateral vessels, confusing side branches, and back flow into distal segments with a diameter greater than 2 mm [34]. Distal anastomosis sites can not be evaluated in as much as 26% of venous grafts [20], making interpretation difficult [33] and contributing to diagnostic error.

Other noninvasive modalities may be used to evaluate grafts. Magnetic resonance angiography has shown promising results, limited by poor image resolution, long scan times, claustrophobia, and degradation from sternal wires, stents, and pacemakers [34, 35]. Although avoiding irradiation, there are contraindications preventing its use in some cardiac patients. Direct comparison of 16-slice MDCT (as a reference standard) with magnetic resonance angiography has demonstrated a sensitivity of 100% and a specificity of 68% [35], with poor image resolution being the main limitation of magnetic resonance angiography. Transthoracic ultrasound has also been described in patency assessment of CABG grafts. It has been shown to have a sensitivity of 50% to 100% and a specificity of 59% to 100% [36], but it is operator dependent.

Study Limitations
Only studies reporting sufficient data for sensitivity and specificity calculations were included. Multiple grafts from each patient were included, with a possible clustering effect. However there is insufficient information to quantify this effect. The quality assessment of diagnostic accuracy studies (QUADAS) analysis showed that reporting of study design (items 12 and 14) may influence accuracy results. Poor reporting strategies may hide deficiencies in study design [8] and should be incorporated into any diagnostic accuracy analysis.

The decision to exclude non-assessable grafts from analysis was preferable to excluding studies that did not provide reference findings for non-assessable grafts, or designating non-assessed grafts as false positives. Although this overestimates diagnostic accuracy, the high rate of visualization in diagnosing occlusion (96%) means that the effect must be small. The effect on stenosis accuracy is less certain, with a higher rate of grafts unable to be assessed (12%).

The lack of specific data on sequential grafts made separate analysis unfeasible. Interpretation of the string sign was rarely mentioned and was interpreted as stenosis on coronary angiography rather than occlusion. The lack of specific documentation means that string sign interpretation within the primary studies is uncertain.

This analysis did not evaluate MDCT accuracy for coexistent native vessel disease, because few studies provided such data. In a study of ungrafted patients [37], 64-slice MDCT had 88% sensitivity for proximal and distal segments, and 97% specificity when compared with angiography for diagnosis of coronary artery stenosis greater than 75%. Another study [38] produced an area under the curve value of 0.97 in identifying candidates for CABG surgery with at least 50% stenosis in the left main stem artery or 70% stenosis in one or more major coronary arteries. Further literature is required for widespread acceptance of its accuracy in patients with arrhythmias or respiratory disease.

The 64-slice MDCT involves initial hardware and software costs, durability, and processing considerations, and a picture archiving and communications system. The scanner choice depends on available technology, with a view to remaining capable of producing acceptable imaging for at least 5 years. These considerations are beyond the scope of this review.

In conclusion, MDCT accuracy in CABG patency and stenosis assessment is excellent compared with angiography. Its safety advantages have led to rapidly increasing usage in both native and grafted vessel evaluation. It can be safely used to exclude significant stenosis or occlusion in grafts without confirmatory angiography. Symptomatic patients can be safely referred for graft assessment by MDCT without the risks of angiography. Multi-detector computed tomographic surveillance of asymptomatic patients is safe and accurate but its clinical value is at present unknown. Beta blocker administration does not significantly improve diagnostic accuracy. The rates of inadequate visualization are 4% for occlusion analysis, and 12% of non-occluded grafts in stenosis analysis. The changing approach to coronary investigation means that cardiac surgeons will soon need to interpret MDCT images of both native and grafted vessels in preparation for primary or re-do coronary bypass grafting procedures.


   References
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 References
 

  1. Eagle K, Guyton RA, Davidoff R, et al. ACC/AHA guidelines for coronary artery bypass graft surgery: a report of the American College of Cardiology/American Heart Association task force on practice guidelines (Committee to revise the 1991 Guidelines for coronary artery bypass graft surgery) J Am Coll Cardiol 1999;34:1262-1347.[Free Full Text]
  2. Cameron AA, Davis KB, Rogers WJ. Recurrence of angina after coronary artery bypass surgery: predictors and prognosis (CASS Registry)Coronary Artery Surgery Study. J Am Coll Cardiol 1995;26:895-899.[Abstract]
  3. FitzGibbon GM, Leach AJ, Kafka HP, Keon WJ. Coronary bypass graft fate: long-term angiographic study J Am Coll Cardiol 1991;17:1075-1080.[Abstract]
  4. Gobel FL, Stewart WJ, Campeau L, et al. Post CABG Trial Investigators Safety of coronary arteriography in clinically stable patients following coronary bypass surgery Cathet Cardiovasc Diagn 1998;45:376-381.[Medline]
  5. Stein PD, Beemath A, Skaf E, et al. Usefulness of 4-, 8-, and 16-slice computed tomography for detection of graft occlusion or patency after coronary artery bypass grafting Am J Cardiol 2005;96:1669-1673.[Medline]
  6. Whiting P, Rutjes AW, Reitsma JB, Bossuyt PM, Kleijnen J. The development of QUADAS: a tool for the quality assessment of studies of diagnostic accuracy included in systematic reviews BMC Med Res Methodol 2003;10:25.
  7. Walter SD. Properties of the summary receiver operating characteristic (SROC) curve for diagnostic test data Statist Med 2002;21:1237-1256.
  8. Westwood ME, Whiting PF, Kleijnen J. How does study quality affect the results of a diagnostic meta-analysis? BMC Med Res Methodol 2005;5:20.[Medline]
  9. Suzuki S, Moro-oka T, Choudhry NK. The conditional relative odds ratio provided less biased results for comparing diagnostic test accuracy in meta-analyses J Clin Epidemiol 2004;57:461-469.[Medline]
  10. Irwig L, Tosteson ANA, Gatsonis C, et al. Guidelines for meta-analysis evaluating diagnostic tests Ann Intern Med 1994;120:667-676.[Abstract/Free Full Text]
  11. Song MH, Ito T, Watanabe T, Nakamura H. Multidetector computed tomography versus coronary angiogram in evaluation of coronary artery bypass grafts Ann Thorac Surg 2005;79:585-588.[Abstract/Free Full Text]
  12. Anders K, Baum U, Schmid M, et al. Coronary artery bypass graft (CABG) patency: assessment with high-resolution submillimeter 16-slice multidetector-row computed tomography (MDCT) versus coronary angiography Eur J Radiol 2006;57:336-344.[Medline]
  13. Bartnes K, Sildnes T, Iqbal A, et al. Coronary bypass graft patency cannot be determined by multidetector spiral computed tomography Scand Cardiovasc J 2006;40:83-86.[Medline]
  14. Burgstahler C, Beck T, Kuettner A, et al. Non-invasive evaluation of coronary artery bypass grafts using 16-row multi-slice computed tomography with 188 ms temporal resolution Int J Cardiol 2006;106:244-249.[Medline]
  15. Chiurlia E, Menozzi M, Ratti C, Romagnoli R, Modena MG. Follow-up of coronary artery bypass graft patency by multislice computed tomography Am J Cardiol 2005;95:1094-1097.[Medline]
  16. Leta R, Carreras F, Alomar X, et al. Non-invasive coronary angiography with 16 multidetector-row spiral computed tomography: a comparative study with invasive coronary angiography Rev Esp Cardiol 2004;57:217-224.[Medline]
  17. Malhotra R, Mishra M, Khurana P, et al. Three-dimensional reconstruction of ultrafast 16-slice computed tomography images and CT angiography versus conventional coronary angiography at one year in multivessel coronary artery bypass surgery Innovations 2005;1:92-95.
  18. Martuscelli E, Romagnoli A, D’Eliseo A, et al. Evaluation of venous and arterial conduit patency by 16-slice spiral computed tomography Circulation 2004;110:3234-3238.[Abstract/Free Full Text]
  19. Salm LP, Bax JJ, Jukema JW, et al. Comprehensive assessment of patients after coronary artery bypass grafting by 16-detector-row computed tomography Am Heart J 2005;150:775-781.[Medline]
  20. Schlosser T, Konorza T, Hunold P, Kuhl H, Schmermund A, Barkhausen J. Noninvasive visualization of coronary artery bypass grafts using 16-detector row computed tomography J Am Coll Cardiol 2004;44:1224-1229.[Abstract/Free Full Text]
  21. Song W, Jin SX, Du YP, Liu JP, He B, Wang BY. The clinical value of sixteen-detector row computed tomography angiography for the assessment of coronary artery bypass graft Zhonghua Xin Xue Guan Bing Za Zhi 2005;33:704-707.[Medline]
  22. Stauder N, Kuettner A, Schroder S, et al. Coronary artery bypass grafts: assessment of graft patency and native coronary artery lesions using 16-slice MDCT. Eur Radiol 2006(epub ahead of print).
  23. Trigo Bautista A, Estornell J, Ridocci F, et al. Non-invasive assessment of coronary artery bypass grafts by computed tomography: comparison with conventional coronary angiography Rev Esp Cardiol 2005;58:807-814.[Medline]
  24. Yamamoto M, Kimura F, Niinami H, Suda Y, Ueno E, Takeuchi Y. Noninvasive assessment of off-pump coronary artery bypass surgery by 16-channel multidetector-row computed tomography Ann Thorac Surg 2006;81:820-827.[Abstract/Free Full Text]
  25. Pache G, Saueressig U, Frydrychowicz A, et al. Initial experience with 64-slice cardiac CT: non-invasive visualization of coronary artery bypass grafts Eur Heart J 2006;27:976-980.[Abstract/Free Full Text]
  26. Schroeder S, Kopp AF, Kuettner A, et al. Influence of heart rate on vessel visibility in noninvasive coronary angiography using new multislice computed tomography: experience in 94 patients Clin Imag 2002;26:106-111.[Medline]
  27. Nieman K, Rensing BJ, van Geuns RJ, et al. Non-invasive coronary angiography with multislice spiral computed tomography: impact of heart rate Heart 2002;88:470-474.[Abstract/Free Full Text]
  28. Gurevitch J, Gaspar T, Orlov B, et al. Noninvasive evaluation of arterial grafts with newly released multidetector computed tomography Ann Thorac Surg 2003;76:1523-1527.[Abstract/Free Full Text]
  29. Hunold P, Vogt FM, Schmermund A, et al. Radiation exposure during cardiac CT: effective doses at multi-detector row CT and electron-beam CT Radiology 2003;226:145-152.[Abstract/Free Full Text]
  30. Jakobs TF, Becker CR, Ohnesorge B, et al. Multislice helical CT of the heart with retrospective ECG gating: reduction of radiation exposure by ECG-controlled tube current modulation Eur Radiol 2002;12:1081-1086.[Medline]
  31. Kopp AF, Schroeder S, Kuettner A, et al. Coronary arteries: retrospectively ECG-gated multi-detector row CT angiography with selective optimization of the image reconstruction window Radiology 2001;221:683-688.[Abstract/Free Full Text]
  32. Hong C, Becker CR, Huber A, et al. ECG-gated reconstructed multi-detector row CT coronary angiography: effect of varying trigger delay on image quality Radiology 2001;220:712-717.[Abstract/Free Full Text]
  33. Nieman K, Oudkerk M, Rensing BJ, et al. Coronary angiography with multi-slice computed tomography Lancet 2001;357:599-603.[Medline]
  34. Marano R, Storto ML, Maddestra N, Bonomo L. Non-invasive assessment of coronary artery bypass graft with retrospectively ECG-gated four-row multi-detector spiral computed tomography Eur Radiol 2004;14:1353-1362.[Medline]
  35. Stauder NI, Fenchel M, Stauder H, et al. Assessment of minimally invasive direct coronary artery bypass grafting of the left internal thoracic artery by means of magnetic resonance imaging J Thorac Cardiovasc Surg 2005;129:607-614.[Abstract/Free Full Text]
  36. Jones CM, Athanasiou A, Tekkis P, et al. Does Doppler echography have a diagnostic role in patency assessment of internal thoracic artery grafts? Eur J Cardiothorac Surg 2005;28:692-700.[Abstract/Free Full Text]
  37. Leber AW, Knez A, von Ziegler F, et al. Quantification of obstructive and nonobstructive coronary lesions by 64-slice computed tomography: a comparative study with quantitative coronary angiography and intravascular ultrasound J Am Coll Cardiol 2005;46:147-154.[Abstract/Free Full Text]
  38. Hoffmann MH, Shi H, Schmitz BL, et al. Noninvasive coronary angiography with multislice computed tomography JAMA 2005;293:2471-2478.[Abstract/Free Full Text]



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