Multi-detector row spiral CT pulmonary angiography: comparison with single-detector row spiral CT.

PURPOSE: To compare vascular conspicuity and ability to connect pulmonary arterial branches on pulmonary angiograms obtained with helical multi-detector row computed tomography (CT) with those on pulmonary angiograms obtained with helical single-detector row CT. MATERIALS AND METHODS: Of 93 consecutive patients suspected of having pulmonary embolism, 48 underwent scanning with multi-detector row CT and 45 with single-detector row CT; scans were obtained in 9 seconds and 28 seconds with 2.5-mm and 3.0-mm collimation, respectively. The lungs were divided into three zones: central, middle, and peripheral. Two independent observers used five-point grading scales. RESULTS: Conspicuity of pulmonary arteries in the central zone was ranked equal (median of 5), but in the middle and peripheral zones it was significantly higher at multi-detector row CT than at single-detector row CT (median 5 vs 4 and 4 vs 3, P < .001, respectively). In addition, multi-detector row CT improved the ability to connect peripheral arteries with their more centrally located pulmonary artery of origin in the peripheral but not the middle zone on transverse images and in both zones on multiplanar images. Viewing with a modified window setting (width, 1,000 HU; level, -100 HU) significantly increased pulmonary arterial conspicuity. Contrast material column in the pulmonary arteries was significantly more homogeneous at multi-detector row CT. CONCLUSION: Use of multi-detector row CT significantly improves pulmonary arterial visualization in the middle and peripheral lung zones.     

Multi-detector row CT artifacts that mimic disease

PURPOSE: To determine retrospectively the frequency of two artifact patterns that mimic pathologic lesions on computed tomographic (CT) head images acquired in the axial scanning mode with two different multi-detector row CT systems at the same institution. MATERIALS AND METHODS: The institutional review board approved this Health Insurance Portability and Accountability Act-compliant study and waived informed consent. The study involved two groups of consecutive patients, a group of 22 (nine men, 13 women; mean age, 56 years; age range, 27-85 years) examined with one multi-detector row CT system with four detector rows, and another group of 13 (seven men, six women; mean age, 69 years; age range, 53-81 years) examined with a different four-detector row CT system. Examinations in each group took place in a 4-week period. CT images were retrospectively evaluated by a neuroradiologist and a physicist for presence, appearance, location (within the image set and on individual images), and size of artifacts. Elimination of artifacts was verified by scanning a water phantom after scanner service and repair. RESULTS: A pseudolesion, or artifact, was identified in scans of four of 22 patients examined with the first scanner and eight of 13 patients examined with the second scanner. The artifact on images obtained on the first scanner, an approximately 2-cm-diameter faintly hyperattenuating and nonenhancing area with hypoattenuating collar, was found at gantry isocenter on every fourth image. A different pattern was found on images obtained on the second scanner: a 1.1-cm-diameter circular area of hypoattenuation with a faintly attenuating rim, that mimicked a cyst. This artifact was observed also at the CT scanner gantry isocenter on every fourth image. Artifacts disappeared after recalibration (first scanner) or collimator cleaning (second scanner). CONCLUSION: CT scanning in the axial mode can produce a regularly repeating artifact when data from one detector row of a multi-detector row CT scanner are compromised. Because of the risk of misinterpreting such patterns, routine assessment of each detector element is recommended for multi-detector row CT scanners that are routinely used in the axial scanning mode.     

Multi-detector row CT systems and image-reconstruction techniques

The introduction in 1998 of multi-detector row computed tomography (CT) by the major CT vendors was a milestone with regard to increased scan speed, improved z-axis spatial resolution, and better utilization of the available x-ray power. In this review, the general technical principles of multi-detector row CT are reviewed as they apply to the established four- and eight-section systems, the most recent 16-section scanners, and future generations of multi-detector row CT systems. Clinical examples are used to demonstrate both the potential and the limitations of the different scanner types. When necessary, standard single-section CT is referred to as a common basis and starting point for further developments. Another focus is the increasingly important topic of patient radiation exposure, successful dose management, and strategies for dose reduction. Finally, the evolutionary steps from traditional single-section spiral image-reconstruction algorithms to the most recent approaches toward multisection spiral reconstruction are traced.     

Multi-detector row CT: principles and practice for abdominal applications

Abdominal imaging with multi-detector row computed tomography (CT) can be performed during short breath holds. On 16-channel multi-detector row CT scanners, the effective detector row thickness, depending on the manufacturer, is typically 1.0-1.5 mm, which results in a beam collimation of 16-24 mm. At a gantry rotation speed of 0.5 second and a pitch of 1, the table travel speed will be 32-48 mm/sec. At a smaller effective detector row thickness and a narrower beam collimation, a slightly higher pitch may be needed to obtain short-breath-hold CT scans. Typically, transverse scans are viewed at a reconstructed section thickness of 3-5 mm, with thinner sections used for CT angiography and whenever off-axial reformations are obtained. The radiologic technique should be optimized according to the transverse section thickness used for interpretation, and the contrast material administration protocol should be optimized according to the clinical problem, with the scanning triggered for enhancement of a target organ.     

Single versus multi-detector row CT: comparison of radiation doses and dose profiles

RATIONALE AND OBJECTIVES: The purpose of this study was twofold: (a) to compare the radiation dose profile between computed tomography (CT) with a single detector row (SD) and with a multi-detector row (MD) and (b) to compare specific organ doses between SD CT and MD CT. MATERIALS AND METHODS: Thermoluminescent dosimeters placed within a 32-cm-diameter cylindrical phantom were used to measure and compare dose profiles from one SD CT scanner and from one MD CT scanner. SD CT scanning parameters were 210 mA, 140 kVp, pitch of 1.0, 5-mm section thickness, and 0.8-second gantry rotation speed. MD CT scanning parameters were 130 mA, 140 kVp, pitch of 0.75, 4 x 5-mm section thickness, 15-mm table feed, and 0.8-second gantry rotation speed. To plot radiation dose profile, doses were measured both in the imaging plane and in the area adjacent to the imaging plane. The resultant data were normalized to achieve constant image noise between MD CT and SD CT. Direct doses to individual organs from primary and scattered radiation were measured with an anthropomorphic phantom containing thermoluminescent dosimeters and with a standard pelvic imaging protocol for both MD CT and SD CT. RESULTS: MD CT resulted in a dose profile approximately 27% higher than that from SD CT in the plane of imaging (8.0 vs 6.3 mGy) and 69% higher adjacent to the plane of imaging (6.8 vs 4.0 mGy). The individual doses to the kidneys, uterus, ovaries, and pelvic bone marrow were 92%-180% higher with MD CT than with SD CT. CONCLUSION: With image noise constant between SD CT and MD CT, the radiation dose profile both inside and outside the plane of imaging was higher with MD CT than with SD CT. Organ dose also was higher with MD CT than with SD CT. This difference should be accounted for in the design of MD CT protocols, especially as MD CT technology becomes more widely available for clinical use.     

腹腔及腹膜后间隙淋巴结结核的多层螺旋CT强化特征

目的研究腹腔及腹膜后间隙淋巴结结核的多层螺旋CT强化特征,以提高该疾病的影像诊断水平。方法收集本院经临床病理证实的腹部淋巴结结核19例,在多层螺旋CT强化图像上,观察受累淋巴结的大小、形态、密度、强化类型、优势解剖分布以及淋巴结外器官病变的强化特征。结果94.7%淋巴结结核呈典型的环状强化,仅5.3%增大的淋巴结呈均匀强化。腹部淋巴结结核常优势地累及肠系膜(73.7%)、门腔间隙(63.2%)、肝十二指肠韧带(57.9%)、肝胃韧带(47.4%)和腹主动脉周围上部淋巴结(47.4%)。9例(47.4%)脾增大,其中5例(26.3%)脾内有多发低密度灶,病灶周边强化;6例(31.5%)腹腔积液;3例(15.8%)大网膜、肠系膜和壁层腹膜广泛结节样增厚。结论结核累及腹腔及腹膜后间隙淋巴结的多层螺旋CT强化具有一定特征。     

Multi-detector row spiral CT angiography of the thoracic outlet: dose reduction with anatomically adapted online tube current modulation and preset dose savings

PURPOSE: To evaluate image quality obtained with anatomically adapted online tube current modulation and preset minimum dose savings at multi-detector row spiral computed tomographic (CT) angiography of the thoracic outlet. MATERIALS AND METHODS: A total of 100 patients were evaluated for thoracic outlet arterial syndrome with spiral CT angiography (collimation, 4 x 1 mm; pitch, 1.75) both with and without dose reduction by means of anatomically adapted online tube current modulation and preset minimum dose savings. Preset minimum savings of 20% and of 32% were applied in two groups of 50 patients (groups 1 and 2). In each group, low-dose scanning was performed in 25 patients in the neutral position and in 25 patients after postural maneuver. Tube current-time product, noise, presence and quality of graininess and of linear streak artifacts on transverse CT scans, and diagnostic value of sagittal reformations and volume-rendered images were evaluated and recorded for each data set. chi2 test was used to compare frequencies; paired Wilcoxon rank test, to compare subjective and objective image quality scores. P <.05 indicated a significant difference. RESULTS: In group 1, mean tube current-time product was 3225 mAs for reference scans and 2101 mAs for low-dose scans (mean reduction, 35%; range, 27%-47%). In group 2, mean was 3070 mAs for reference scans and 2068 mAs for low-dose scans (mean reduction, 33%; range, 17%-38%). In group 1, no differences in frequencies of graininess and linear streaking or in noise level were found between images acquired with or without dose reduction. In group 2, no difference was found in noise level between low-dose and reference scans. On low-dose scans, moderate linear streaking was observed with lower frequency and moderate graininess was observed with higher frequency, but artifacts did not compromise image quality or prevent confident assessment of arterial diameter in the three compartments of the thoracic outlet. CONCLUSION: Online tube current modulation with a preset minimum dose saving of 20% allowed 35% reduction in mean tube current-time product, with no loss in image quality.     

Pulmonary embolism: radiation dose with multi-detector row CT and digital angiography for diagnosis

PURPOSE: To compare radiation dose delivered at four- and 16-detector row computed tomography (CT) with a dose-modulation program and that delivered at digital angiography for evaluation of pulmonary embolism (PE). MATERIALS AND METHODS: The part of the study involving patients (seven women, four men; mean age, 62 years +/- 16 [standard deviation]; range, 41-85 years) was approved by the institutional review board. Patients gave written informed consent. Exposure was performed with an anthropomorphic phantom with thermoluminescent dosimeters for four-detector row CT without the dose-modulation program and 16-detector row CT without and with the dose-modulation program with standard protocols for pulmonary CT angiography (120 kV, 144 mAs, four and 16 detector rows with 1.00- and 0.75-mm section thickness, respectively). Digital angiograms were acquired with four standard projections at 80 kV. For digital angiography, radiation dose was calculated according to phantom measurements and adapted to acquisition and fluoroscopy times. Distribution of dose was compared for CT and digital angiography. RESULTS: During pulmonary CT angiography, mean radiation dose delivered at middle of chest was 21.5, 19.5, and 18.2 mGy for four-detector row CT and for 16-detector row CT without and with dose-modulation program, respectively. At the same level, a mean dose of 91 mGy was delivered with digital angiography. The dose adjusted to clinical conditions was 139.0 mGy for digital angiography and could be reduced after technical adjustment. Ratios of maximum dose to mean dose were 1.15 and 2.96 for CT and digital angiography, respectively. With application of the dose-modulation program at 16-detector row CT, radiation dose was reduced 15%-20% at the upper chest. CONCLUSION: Multi-detector row CT delivers a lower radiation dose, with better spatial distribution of dose, than does pulmonary CT angiography. With 16-detector row CT and a dose-modulation program, radiation dose is decreased during PE work-up.     

Multi-detector row CT pulmonary angiography: comparison of standard-dose and simulated low-dose techniques

PURPOSE: To compare standard-dose and simulated low-dose multi-detector row computed tomography (CT) pulmonary angiography. MATERIALS AND METHODS: The institutional review board approved the study protocol and waived patient informed consent because the study was based on existing data. Raw data from 21 CT scans obtained at 90 mAs (effective) in 11 women and 10 men aged 25-74 years (mean, 52 years) that showed at least one filling defect within a pulmonary artery were used to simulate CT pulmonary angiography with reduced radiation doses, at 60, 40, 20, and 10 mAs. Three independent readers coded each central and segmental pulmonary artery twice as positive, negative, or inconclusive for presence of a filling defect. The second reading of images obtained with 90 mAs was considered the reference standard. The potential dependence of results on reader, radiation dose, and/or pulmonary artery segment was investigated with analysis of variance. Positive and negative consistent values were calculated for standard-dose scans and simulated low-dose scans in the first reading session. The branching order of the artery with the most distal filling defect was recorded. The quality of intravascular contrast at each tube current-time product setting was scored on a five-point scale. Interreader agreement was investigated with kappa statistics. RESULTS: The frequencies of positive and inconclusive results (P = .21 and .08, respectively), positive and negative consistent values (P = .19 and .34, respectively), and branching order of the most distal artery with a filling defect (P = .41) did not depend on the radiation dose. Values for inter- and intrareader agreement were higher for central arterial segments than for branch arteries but were not influenced by dose reduction, regardless of arterial segment. The quality of intravascular contrast was not significantly changed when the tube current-time product was reduced from 90 to 40 mAs (P = .10 to >.99). CONCLUSION: The evaluated parameters remained stable when tube current-time product was reduced from 90 (effective) to 10 (simulated) mAs at multi-detector row CT pulmonary angiography.     

Multi-detector row CT of the small bowel: peak enhancement temporal window--initial experience

PURPOSE: To prospectively determine quantitatively and qualitatively the timing of maximal enhancement of the normal small-bowel wall by using contrast material-enhanced multi-detector row computed tomography (CT). MATERIALS AND METHODS: This HIPAA-compliant study was approved by the institutional review board. After information on radiation risk was given, written informed consent was obtained from 25 participants with no history of small-bowel disease (mean age, 58 years; 19 men) who had undergone single-level dynamic CT. Thirty seconds after the intravenous administration of contrast material, a serial dynamic acquisition, consisting of 10 images obtained 5 seconds apart, was performed. Enhancement measurements were obtained over time from the small-bowel wall and the aorta. Three independent readers qualitatively assessed small-bowel conspicuity. Quantitative and qualitative data were analyzed during the arterial phase, the enteric phase (which represented peak small-bowel mural enhancement), and the venous phase. Statistical analysis included paired Student t test and Wilcoxon signed rank test with Bonferroni correction. A P value less than .05 was used to indicate a significant difference. RESULTS: The mean time to peak enhancement of the small-bowel wall was 49.3 seconds +/- 7.7 (standard deviation) and 13.5 seconds +/- 7.6 after peak aortic enhancement. Enhancement values were highest during the enteric phase (P < .05). Regarding small-bowel conspicuity, images obtained during the enteric phase were most preferred qualitatively; there was a significant difference between the enteric and arterial phases (P < .001) but not between the enteric and venous phases (P = .18). CONCLUSION: At multi-detector row CT, peak mural enhancement of the normal small bowel occurs on average about 50 seconds after intravenous administration of contrast material or 14 seconds after peak aortic enhancement.     

Multi-detector row CT of acute non-traumatic abdominal pain: contrast and protocol considerations

This article discusses the critical protocol considerations in imaging patients with abdominal pain in the emergency department, specifically, the use of oral contrast, intravenous contrast, image postprocessing, and radiation dose. These considerations related to the use of computed tomography imaging of abdominal pain are reviewed in an evidence-based fashion.     

Multi-detector row CT angiography of the brain at various kilovoltage settings

PURPOSE: To investigate image quality and vascular delineation of multi-detector row computed tomographic (CT) angiography at various kilovoltage settings. MATERIALS AND METHODS: Thirty patients were investigated with a standardized CT protocol, with three groups of 10 consecutive patients examined at 80, 120, and 140 kV, respectively. Three blinded readers independently evaluated images and graded image quality parameters, diagnostic confidence, and vascular delineation of intracranial arteries and veins. Vascular CT attenuation values, CT dose indices, and dose length products were assessed quantitatively. For data analysis, a Kruskal-Wallis nonparametric rank F test was used to identify trends and variables that required modeling attention. A proportional odds multinomial regression model was then fit with generalized estimating equations to account for the correlated nature of the data. RESULTS: Image quality was rated higher with higher kilovoltage settings (P <.001). The severity of imaging artifacts was higher with lower kilovoltage settings (P <.001), while the subjectively rated vessel contrast was lower in the 80-kV group than in the 120-kV group and the 140-kV group (P <.05). Diagnostic confidence was higher in the 120-kV group and 140-kV group (P <.005). Vascular delineation was higher with higher kilovoltage settings for most arterial and venous structures. Differences were more significant for structures in close topographic proximity to bone and for subsegmental arteries and were less significant and, in parts, not significant for the main arterial branches and the large venous sinus. Attenuation values were higher with lower kilovoltage settings (P <.05). The mean dose length product could be reduced from 594 mGy. cm in the 140-kV group to 152 mGy.cm in the 80-kV group. CONCLUSION: This multireader study of image quality and vessel delineation with cranial multi-detector row CT angiography at various kilovoltage settings demonstrated a superiority of higher voltages with most pronounced effects for vessels adjacent to bone and subsegmental arteries.     

Multi-detector row CT angiography of lower extremity arterial inflow and runoff: initial experience

PURPOSE: To assess the patterns of lower extremity arterial inflow and runoff opacification with four-channel multi-detector row computed tomographic (CT) angiography in a cohort of patients with disease warranting imaging of the lower extremity arterial system. MATERIALS AND METHODS: Twenty-four patients with symptomatic lower extremity arterial occlusive or aneurysmal disease underwent imaging with four-channel multi-detector row CT from the supraceliac abdominal aorta through the feet. Transverse sections were acquired with a 2.5-mm nominal detector width and pitch of 6.0 (3.2-mm effective section thickness) following intravenous injection of 174-185 mL of iodinated contrast medium (300 mg iodine per milliliter). In each patient, attenuation measurements were recorded in 16 arterial and 16 venous locations. In 18 patients, two radiologists assessed the detectability and stenosis degree of 21 arterial segments per patient relative to these features at conventional angiography. RESULTS: A mean scanning time of 66 seconds was required to cover a mean of 1,233 mm, resulting in a mean of 908 transverse reconstructions. All 504 arterial segments were depicted and analyzable. Mean arterial attenuation ranged from 253 HU in the midabdominal aorta to 357 HU in the popliteal artery and 253 HU in the dorsalis pedis or posterior tibial artery measured inferior to the tibiotalar joint. Maximum mean venous enhancement (99 HU) was observed in the saphenous vein at the ankle, with all other venous stations measuring less than 74 HU. CONCLUSION: The arteries of lower extremity inflow and runoff can be reliably depicted with minimal venous enhancement by using multi-detector row CT.     

多层螺旋CT与M型超声心动图评估左室功能的对照研究

目的：用多层螺旋CT（multi-detector row computed tomography,MRCT）测量并评估左室功能的各项参数,并与M型超声心动图测量得到的结果进行比较。方法：62位冠心病或可疑患有冠心病的患者（男性40人、女性22人,平均年龄64.2±11.1岁）在24h内接受回顾性心电门控16通道MRCT心脏增强扫描及心脏M型超声心动图检查。在GEAW4.1CT工作站上测量出每位患者的左室舒张末期容积（LVEDV）、左室收缩末期容积（LVESV）并根据公式（LVEDV-LVESV）/LVEDV×100%计算出左室射血分数（LVEF）,并用简单直线回归分别分析MRCT测量所得参数与M型超声心动图测得结果的相关性。结果：16层CT测得的LVEDV为125.4±62.1ml、LVESV为52.8±59.3ml、LVEF为62.9±13.4%,与M型超声心动图测量结果（Teichholz校正公式法）有很好的相关性〔LVEDV为112.8±49.7ml（r=0.826,P〈0.001）、LVESV为45.9±47.0ml（r=0.960,P〈0.001）、LVEF为64.8±13.9%（r=0.916,P〈O．001）]。结论：回顾性心电门控MRCT心脏增强扫描可以应用于临床心功能的评估诊断。     

Multi-detector row CT urography: comparison of strategies for depicting the normal urinary collecting system

PURPOSE: To evaluate several protocols for depiction of the urinary collecting system with multi-detector row computed tomographic (CT) urography. MATERIALS AND METHODS: Fifty-one patients with hematuria or a suspicious renal mass underwent CT urography, during which thinly collimated (1-mm) pyelographic phase scanning was performed 8-10 minutes after contrast medium administration. Patients were examined while prone only (n = 17) and while both prone and supine (n = 17) after a 250-mL infusion of normal saline. Each collecting system and ureter was divided into six segments that were assigned opacification scores. All acquisition techniques were compared, and the highest-scoring technique was compared with that in 17 patients who underwent conventional intravenous urography (IVU). Three reconstruction techniques (transverse, coronal, and maximal intensity projection) were also compared. Stratified analysis was performed with the paired two-tailed Student t test to compare opacification scores for both the acquisition techniques and display methods, both individually and in all possible combinations. RESULTS: CT urography with supplemental saline administration, performed with the patient prone or supine, significantly improved mean opacification scores in the distal ureters (right, P =.004; left, P =.006). With this technique, CT urography produced a mean opacification score that was not significantly different from that with IVU in 11 of 12 segments and was significantly better than that with IVU in one of 12 segments (lower left ureter). Mean opacification scores obtained with transverse or coronal displays were equal to or higher than those obtained with maximum intensity projection reconstructions in all segments. CONCLUSION: CT urography with a multi-detector row scanner and supplemental infusion of normal saline reliably displays the opacified urinary collecting system.     

Multi-detector row CT angiography in the assessment of coronary in-stent restenosis: a systematic review

Purpose

The aim of this study was to perform a systematic review of the diagnostic accuracy of multi-detector row computed tomography angiography (MDCT) for detection of coronary in-stent restenosis in patients treated with coronary stenting when compared to invasive catheter angiography.

Materials and methods

A search of PUBMED and MEDLINE databases for English literature was performed. Only studies with at least 10 patients comparing 16- or more detector rows MDCT angiography with invasive catheter angiography in the detection of coronary in-stent restenosis (more than 50% stenosis) were included for analysis. Sensitivity and specificity estimates pooled across studies were tested using a fixed effects model.

Results

15 studies met selection criteria for inclusion in the analysis. There were eight studies performed with 16-detector row CT scanners, and five studies with 64-detector row scanners and one study with a 40-detector scanner. The remaining study was performed with a mixture of 16-and 64-detector row scanners. Prevalence of in-stent restenosis following coronary stenting was 18% (95% CI: 13, 24%). Pooled estimates of the sensitivity and specificity of overall MDCT angiography for the detection of coronary in-stent restenosis was 85% (95% CI: 78, 90%) and 97% (95% CI: 95, 98%), respectively. No significant difference was found between 16- and 64-detector row scanners regarding the sensitivity and specificity of MDCT for assessment of in-stent restenosis (p > 0.05).

Conclusion

The results showed that MDCT angiography (with 16 or more detector rows) has moderate sensitivity and high specificity for the detection of coronary in-stent restenosis when compared to invasive catheter angiography. A high specificity value of MDCT may be most valuable as a non-invasive technique of excluding coronary stent restenosis or occlusion. The main factors affecting visualization are stent diameters and stent materials.     

Multi-detector row CT coronary angiography in patients with cardiomyopathy -- initial single-centre experience

AIMS: To evaluate the diagnostic accuracy of computed tomography (CT) in assessing haemodynamically significant coronary artery stenoses in patients with cardiomyopathy (CM). SUBJECTS AND METHODS: Eighteen patients with CM were approached to undergo CT coronary angiography to evaluate the use of this technique for investigating the presence of significant coronary artery disease (CAD), and also to compare the findings with catheter angiography. RESULTS: On a segment-by-segment analysis the sensitivity, specificity, positive and negative predictive values in the CM group were 66.7, 96.5, 40 and 98.8%, respectively, with 100% accuracy in "whole-patient terms". CONCLUSION: Non-invasive, 16-detector row CT coronary angiography in patients with presumed CM would seem to be a useful clinical tool for the exclusion of significant coronary artery disease. However, the presence of suboptimal contrast opacification in this patient group means that the implication of these results must be interpreted with caution.     

Multi-detector row CT versus coronary angiography: preoperative evaluation before totally endoscopic coronary artery bypass grafting

PURPOSE: To assess multi-detector row spiral computed tomography (CT) for preoperative evaluation of patients undergoing totally endoscopic coronary artery bypass grafting and to correlate the data with coronary angiographic and intraoperative findings. MATERIALS AND METHODS: Thirty-six patients preoperatively underwent multi-detector row CT (4 x 1-mm collimation, pitch of 1.5, 500-msec rotation time, retrospective electrocardiographic gating, 1.25-mm effective section thickness) and coronary angiography. Assessment criteria for both techniques were visibility and cardiac course of coronary arteries, localization and degree of stenoses, composition of atherosclerotic plaques, and vascular diameter at anastomosis site. Site for distal bypass anastomosis was recommended. Results at multi-detector row CT were calculated relative to results at coronary angiography and surgery. RESULTS: Multi-detector row CT properly displayed 79.4% (154 of 194) of all surgical relevant coronary segments and 80.4% (434 of 540) of all coronary segments. For coronary angiography, ratios of 88.7% (172 of 194) and 94.6% (511 of 540), respectively, were observed. For detection of calcified plaques, multi-detector row CT results exceeded those at coronary angiography by a difference of 17% (18 of 18 [100%] compared with 15 of 18 [83%]). Hemodynamically relevant stenoses were identified with multi-detector row CT in 76% (42 of 55) of cases. Bridging of coronary segments through either myocardium (four of five) or epicardial fat (two of three) was better identified at multi-detector row CT than it was at coronary angiography (one of five compared with zero of three, respectively). At multi-detector row CT, 76% (28 of 37) of all distal bypass touchdown segments were identified, but at coronary angiography, only 70% (26 of 37) were identified. CONCLUSION: Multi-detector row CT provides extended information about coronary target site and therefore should be regarded as an ideal additive planning tool for complex minimally invasive procedures such as totally endoscopic coronary artery bypass grafting or minimally invasive direct coronary artery bypass grafting.