Interpretation of cardiac wall motion from cine-MRI combined with parametric imaging based on the Hilbert transform.

OBJECT: The aim of this study was to test and validate the clinical impact of parametric amplitude images obtained using the Hilbert transform on the regional interpretation of cardiac wall motion abnormalities from cine-MR images by non-expert radiologists compared with expert consensus. MATERIALS AND METHODS: Cine-MRI short-axis images obtained in 20 patients (10 with myocardial infarction, 5 with myocarditis and 5 with normal function) were processed to compute a parametric amplitude image for each using the Hilbert transform. Two expert radiologists blindly reviewed the cine-MR images to define a gold standard for wall motion interpretation for each left ventricular sector. Two non-expert radiologists reviewed and graded the same images without and in combination with parametric images. Grades assigned to each segment in the two separate sessions were compared with the gold standard. RESULTS: According to expert interpretation, 264/320 (82.5%) segments were classified as normal and 56/320 (17.5%) were considered abnormal. The accuracy of the non-expert radiologists' grades compared to the gold standard was significantly improved by adding parametric images (from 87.2 to 94.6%) together with sensitivity (from 64.29 to 84.4%) and specificity (from 92 to 96.9%), also resulting in reduced interobserver variability (from 12.8 to 5.6%). CONCLUSION: The use of parametric amplitude images based on the Hilbert transform in conjunction with cine-MRI was shown to be a promising technique for improvement of the detection of left ventricular wall motion abnormalities in less expert radiologists.

Highly-accelerated self-gated free-breathing 3D cardiac cine MRI: validation in assessment of left ventricular function.

OBJECTIVE: This work presents a highly-accelerated, self-gated, free-breathing 3D cardiac cine MRI method for cardiac function assessment. MATERIALS AND METHODS: A golden-ratio profile based variable-density, pseudo-random, Cartesian undersampling scheme was implemented for continuous 3D data acquisition. Respiratory self-gating was achieved by deriving motion signal from the acquired MRI data. A multi-coil compressed sensing technique was employed to reconstruct 4D images (3D+time). 3D cardiac cine imaging with self-gating was compared to bellows gating and the clinical standard breath-held 2D cine imaging for evaluation of self-gating accuracy, image quality, and cardiac function in eight volunteers. Reproducibility of 3D imaging was assessed. RESULTS: Self-gated 3D imaging provided an image quality score of 3.4 ± 0.7 vs 4.0 ± 0 with the 2D method (p = 0.06). It determined left ventricular end-systolic volume as 42.4 ± 11.5 mL, end-diastolic volume as 111.1 ± 24.7 mL, and ejection fraction as 62.0 ± 3.1%, which were comparable to the 2D method, with bias ± 1.96 × SD of -0.8 ± 7.5 mL (p = 0.90), 2.6 ± 3.3 mL (p = 0.84) and 1.4 ± 6.4% (p = 0.45), respectively. CONCLUSION: The proposed 3D cardiac cine imaging method enables reliable respiratory self-gating performance with good reproducibility, and provides comparable image quality and functional measurements to 2D imaging, suggesting that self-gated, free-breathing 3D cardiac cine MRI framework is promising for improved patient comfort and cardiac MRI scan efficiency.

Evaluation of motion-correction methods for dual-gated cardiac positron emission tomography/computed tomography imaging.

BACKGROUND: Dual gating is a method of dividing the data of a cardiac PET scan into smaller bins according to the respiratory motion and the ECG of the patient. It reduces the undesirable motion artefacts in images, but produces several images for interpretation and decreases the quality of single images. By using motion-correction techniques, the motion artefacts in the dual-gated images can be corrected and the images can be combined into a single motion-free image with good statistics. AIM: The aim of the present study is to develop and evaluate motion-correction methods for cardiac PET studies. We have developed and compared two different methods: computed tomography (CT)/PET-based and CT-only methods. METHODS: The methods were implemented and tested with a cardiac phantom and three patient datasets. In both methods, anatomical information of CT images is used to create models for the cardiac motion. RESULTS: In the patient study, the CT-only method reduced motion (measured as the centre of mass of the myocardium) on average 43%, increased the contrast-to-noise ratio on average 6.0% and reduced the target size on average 10%. Slightly better figures (51, 6.9 and 28%) were obtained with the CT/PET-based method. Even better results were obtained in the phantom study for both the CT-only method (57, 68 and 43%) and the CT/PET-based method (61, 74 and 52%). CONCLUSION: We conclude that using anatomical information of CT for motion correction of cardiac PET images, both respiratory and pulsatile motions can be corrected with good accuracy.

Current utilization of cardiac computed tomography in mainland China: A national survey.

BACKGROUND: Surveys that describe the utilization of cardiac CT are available for the United States, Germany, and Taiwan, but not mainland China. OBJECTIVES: To analyze the clinical utilization of cardiac CT in mainland China. METHODS: A 25-item questionnaire was created and 240 tertiary hospitals were randomly selected to participate. Survey data were collected and confirmed by email as well as phone interviews. RESULTS: In total, 237 (99%) hospitals consented to this survey, but 85 were excluded because of lack of cardiac CT patient volume or advanced technology. Finally, 152 (64%) questionnaires were available for analysis. Median patient volume was 1,037 patients (range: 150-8,072) annually. The most common clinical indications for coronary CT angiography were exclusion of coronary artery disease in patients with low to intermediate pretest likelihood, asymptomatic individuals with cardiovascular risk factors, and follow-up after coronary bypass grafting. The median heart rate threshold for beta blocker administration was >70 beats/min; most centers (86%) used sublingual nitroglycerin. Prospectively ECG triggered acquisition was the predominant technique in 44% of hospitals. Most (59%) providers adjusted the tube current to the body mass, but few (16%) adjusted the contrast injection rate. Per case, the mean examination duration was 14.2 min; post-processing time 13.6 min; and reporting time 18.0 min. CONCLUSIONS: Cardiac CT is widely established in clinical practice in mainland China but there is a need for more uniform standards regarding performance and clinical utilization.

Assessment of myocardial bridge and mural coronary artery using ECG-gated 256-slice CT angiography: a retrospective study.

Recent clinical reports have indicated that myocardial bridge and mural coronary artery complex (MB-MCA) might cause major adverse cardiac events. 256-slice CT angiography (256-slice CTA) is a newly developed CT system with faster scanning and lower radiation dose compared with other CT systems. The objective of this study is to evaluate the morphological features of MB-MCA and determine its changes from diastole to systole phase using 256-slice CTA. The imaging data of 2462 patients were collected retrospectively. Two independent radiologists reviewed the collected images and the diagnosis of MB-MCA was confirmed when consistency was obtained. The length, diameter, and thickness of MB-MCA in diastole and systole phases were recorded, and changes of MB-MCA were calculated. Our results showed that among the 2462 patients examined, 336 have one or multiple MB-MCA (13.6%). Out of 389 MB-MCA segments, 235 sites were located in LAD2 (60.41%). The average diameter change of MCA in LAD2 from systole phase to diastole phase was 1.1 ± 0.4 mm, and 34.9% of MCA have more than 50% diameter stenosis in systole phase. This study suggested that 256-slice CTA multiple-phase reconstruction technique is a reliable method to determine the changes of MB-MCA from diastole to systole phase.

A prospective randomized trial comparing image quality, study interpretability, and radiation dose of narrow acquisition window with widened acquisition window protocols in prospectively ECG-triggered coronary computed tomography angiography.

BACKGROUND: Prospectively triggered coronary computed tomography angiography (CTA) is commonly performed with a widened acquisition window to provide flexibility in image reconstruction. OBJECTIVE: We conducted a randomized controlled trial to determine whether the use of a narrow acquisition window in prospectively triggered coronary CTA would allow lower radiation dose while preserving image quality and interpretability. METHODS: Prospective 2-center 2- platform randomized trial that evaluated 205 consecutive patients 96 with widened acquisition (WA) and 109 narrow acquisition (NA) referred for coronary CTA in sinus rhythm and heart rate <65 beats/min. Patients scanned with WA had phases reconstructed at 5% intervals, and each phase was assigned an individual study ID. Images were reviewed with individual phase reconstructions interpreted randomly by 2 level 3 readers with a third for consensus. Images were evaluated with a 5-point Likert scale on a per-vessel basis (best score on any phase). Scores were then dichotomized into diagnostic (score 3-5) compared with nondiagnostic (score 1-2). Readers also reported obstructive coronary artery disease on a per-patient basis. Agreement for the diagnosis of obstructive disease and per-artery interpretability was performed. Signal and noise measurements were also performed. RESULTS: No difference in demographics between groups (P = NS). The signal-to-noise ratio was comparable 12.99 ± 3.4 NA and 12.53 ± 4.13 for the WA (P = 0.45). The median effective dose was 1.78 mSv for NA compared with 3.26 mSv for WA (P < 0.001). Image quality, diagnostic interpretability, interreader agreement, and downstream testing were not significantly different between the 2 groups (P= NS for all). CONCLUSIONS: Coronary CTA with NA resulted in a 47% lower radiation dose without significant difference in study interpretability or image quality or increased downstream resource use or testing.

Congenital left ventricular wall abnormalities in adults detected by gated cardiac multidetector computed tomography: clefts, aneurysms, diverticula and terminology problems.

OBJECTIVES: Our aim was to evaluate congenital left ventricular wall abnormalities (clefts, aneurysms and diverticula), describe and illustrate imaging features, discuss terminology problems and determine their prevalence detected by cardiac CT in a single center. MATERIALS AND METHODS: Coronary CT angiography images of 2093 adult patients were evaluated retrospectively in order to determine congenital left ventricular wall abnormalities. RESULTS: The incidence of left ventricular clefts (LVC) was 6.7% (141 patients) and statistically significant difference was not detected between the sexes regarding LVC (P=0.5). LVCs were single in 65.2% and multiple in 34.8% of patients. They were located at the basal to mid inferoseptal segment of the left ventricle in 55.4%, the basal to mid anteroseptal segment in 24.1%, basal to mid inferior segment in 17% and septal-apical septal segment in 3.5% of cases. The cleft length ranged from 5 to 22 mm (mean 10.5 mm) and they had a narrow connection with the left ventricle (mean 2.5 mm). They were contractile with the left ventricle and obliterated during systole. Congenital left ventricular septal aneurysm that was located just under the aortic valve was detected in two patients (0.1%). No case of congenital left ventricular diverticulum was detected. CONCLUSION: Cardiac CT allows us to recognize congenital left ventricular wall abnormalities which have been previously overlooked in adults. LVC is a congenital structural variant of the myocardium, is seen more frequently than previously reported and should be differentiated from aneurysm and diverticulum for possible catastrophic complications of the latter two.

Paradoxical scintigraphic pattern in regions with myocardial necrosis on myocardial perfusion gated SPECT with 99mTc-tetrofosmin.

OBJECTIVES: To assess the significance of a paradoxical pattern (PP) (greater tracer uptake during stress than at rest) on gated myocardial perfusion SPECT in myocardial regions with myocardial necrosis. METHODS: A review of 1,764 consecutive stress-rest myocardial perfusion SPECT studies in patients with prior myocardial infarction (MI) was conducted. Of these, 117 patients (6.6%) with a PP corresponding to a region with myocardial necrosis were identified. An assessment of perfusion, contractility, wall thickening, scintigraphic criteria for viability, and the characteristics of the culprit artery in regions with a PP was performed. RESULTS: Of the 160 regions with necrosis, 125 (75%) had a PP: 67 in the anterior region and 58 in the inferior-lateral region. In the PP group, the average tracer activity of defects during stress was significantly higher than at rest (P < .0001). Ninety-three (86.6%) out of 110 PP segments without scintigraphic criteria of viability at rest met viability criteria on stress imaging. The artery supplying regions with a PP was patent in 88% of cases. In the remaining patients it was occluded, although collateral circulation was always present. CONCLUSIONS: In scintigraphic segments corresponding to regions with infarction and PP, a mixture of viable and well perfused myocardium was observed. In most cases, the vessel that supplied the region with PP was either patent, or when the artery was occluded, there was evident collateral circulation.

Nomograms for estimating coronary artery disease prognosis with gated stress myocardial perfusion SPECT.

BACKGROUND: Nomograms can be useful tools for estimating coronary artery disease (CAD) risk. We sought to devise risk-based nomograms for stress myocardial perfusion SPECT to include measures of % ischemic myocardium and left ventricular function. METHODS: A total of 4,575 patients were consecutively and prospectively enrolled in the Myoview Prognosis Registry. Multivariable Cox proportional hazards model were employed to estimate CAD death or MI. Nomograms were devised from the results of the Cox models. RESULTS: CAD death or MI rates worsened in a gradient manner by the % ischemic myocardium. Higher risk patients were those with a rest and/or post-stress LVEF ≤ 45%. A nomogram was developed to estimate 2-year CAD death or MI-free survival for exercising and pharmacologic stress patients by their post-stress LVEF and % ischemic myocardium MPS results. Patients undergoing pharmacologic stress with a rest and/or post-stress LVEF ≤ 45% with high risk ischemic findings had the lowest CAD death or MI event-free survival. For exercising patients with a preserved resting LVEF > 45%, 2-year CAD death or MI event-free survival ranged from 99.4% to 89% for 0% to ≥20% ischemic myocardium. Those at highest risk included patients undergoing pharmacologic stress with depressed LVEF. For pharmacologic stress patients with a resting LVEF ≤45%, 2-year CAD death or MI event-free survival ranged from 89% to 48% for 0% to ≥20% ischemic myocardium. For pharmacologic stress patients with a post-stress LVEF ≤ 45%, 2-year CAD death or MI event-free survival ranged from 88% to 46% for 0% to ≥20% ischemic myocardium. A validation cohort revealed moderate-strong correlation between observed and predicted survival (r = 0.71). Average discordance between observed and predicted survival was ≤2% but was greater for higher risk patients with lower predicted survival estimates. CONCLUSIONS: Risk-based nomograms estimating important CAD outcomes may serve as a clinically useful tool to target therapeutic intervention for high risk patient subsets.

Patient radiation doses in cardiac computed tomography: comparison of published results with prospective and retrospective acquisition.

Prospective ECG triggering has the potential of reducing radiation exposure while maintaining diagnostic accuracy of cardiac computed tomography (CT). The aim of this study is to review patient radiation doses associated with coronary artery calcium scoring (CACS) and CT coronary angiography (CTCA) and to compare results between prospective and retrospective acquisition schemes. Patient radiation doses from CACS and CTCA were extracted from 67 relevant studies. Mean effective dose for CACS and CTCA with prospective ECG triggering is significantly lower than retrospective acquisition, 0.9±0.4 vs. 3.1±1.4 mSv, p < 0.001, and 3.4±1.4 vs. 11.1±5.4 mSv, p < 0.001, respectively. In both cardiac CT examinations, application of dose modulation techniques result in significantly lower doses in retrospective schemes, however, even with dose modulation, retrospective acquisition is associated with significantly higher doses than prospective acquisition. The number of slices acquired per rotation and the number of X-ray sources of the CT scanner (single or dual source) do not have a significant effect on patient dose.

Coronary artery assessment by multidetector computed tomography in patients with prosthetic heart valves.

OBJECTIVES: Patients with prosthetic heart valves may require assessment for coronary artery disease. We assessed whether valve artefacts hamper coronary artery assessment by multidetector CT. METHODS: ECG-gated or -triggered CT angiograms were selected from our PACS archive based on the presence of prosthetic heart valves. The best systolic and diastolic axial reconstructions were selected for coronary assessment. Each present coronary segment was scored for the presence of valve-related artefacts prohibiting coronary artery assessment. Scoring was performed in consensus by two observers. RESULTS: Eighty-two CT angiograms were performed on a 64-slice (n = 27) or 256-slice (n = 55) multidetector CT. Eighty-nine valves and five annuloplasty rings were present. Forty-three out of 1160 (3.7%) present coronary artery segments were non-diagnostic due to valve artefacts (14/82 patients). Valve artefacts were located in right coronary artery (15/43; 35%), left anterior descending artery (2/43; 5%), circumflex artery (14/43; 32%) and marginal obtuse (12/43; 28%) segments. All cobalt-chrome containing valves caused artefacts prohibiting coronary assessment. Biological and titanium-containing valves did not cause artefacts except for three specific valve types. CONCLUSIONS: Most commonly implanted prosthetic heart valves do not hamper coronary assessment on multidetector CT. Cobalt-chrome containing prosthetic heart valves preclude complete coronary artery assessment because of severe valve artefacts. KEY POINTS: • Most commonly implanted prosthetic heart valves do not hamper coronary artery assessment • Prosthetic heart valve composition determines the occurrence of prosthetic heart valve-related artefacts • Björk-Shiley and Sorin tilting disc valves preclude diagnostic coronary artery segment assessment.

Cardiac risk assessment by gated single-photon emission computed tomography in asymptomatic end-stage renal disease patients at the start of dialysis.

OBJECTIVES: This study assessed the impact of cardiac risk assessment using gated single-photon emission computed tomography (SPECT) on cardiac events in end-stage renal disease (ESRD) patients. METHODS: We evaluated 215 asymptomatic patients who began dialysis between January 2005 and April 2009. Baseline electrocardiography and echocardiography were performed in all the patients. The subjects were stratified into low- and high-risk groups according to the baseline cardiac status, and gated SPECT was additionally recommended for the high-risk patients. RESULTS: The study population consisted of 50 low- and 165 high-risk patients undergoing SPECT. Among the high-risk patients, 75 (45.5%) showed perfusion defects on SPECT and their overall cardiac-event rate per person-year of follow-up was 15.0%, significantly higher than 4.5% in high-risk group without perfusion defect and 1.2% in low-risk group. The presence of perfusion defect was a significant independent predictor of adverse cardiac events [hazard ratio (HR) 2.11; 95% confidence interval (CI) 1.05-4.24; P = .035]. When gated SPECT was added to the clinical and the echocardiographic variables, the prognostic stratification significantly improved (P < .001). However, coronary revascularization was not associated with improved cardiac event-free survival (HR 0.62; 95% CI 0.26-1.52; P = .296). CONCLUSIONS: Gated SPECT may provide additional prognostic information for cardiac risk stratification, particularly among high-risk patients starting dialysis.

Myocardial perfusion GSPECT imaging in patients with myocardial bridging.

BACKGROUND: The aim of this study was to investigate the incidence, reversibility, and severity of LV perfusion abnormalities in patients with isolated myocardial bridges using a gated myocardial perfusion SPECT study (GSPECT). METHODS: A retrospective study involved 42 patients without history of myocardial infarction, with isolated myocardial bridges detected in coronary angiography and no substantial evidence of atherosclerotic changes in coronary arteries. In all patients a gated SPECT study was performed at both rest and stress, after intravenous administration of (99m)Tc MIBI. Reconstructed slices were analyzed using a 20-segment model of the left ventricle. RESULTS: Incidence and severity of stress-induced ischemia were related to degree of artery constriction (P = .002 and .00014, respectively). Perfusion abnormalities were detected only in patients with critical narrowing (≥ 50%) of artery (in 12 out of 28, i.e., 43% of patients). Summed stress scores (SSS) ranged from 4 to 11 (mean 7), indicating slight or moderate defect intensity. Only 1 patient presented with a SSS value of 31 (severe defect). Perfusion defects were stress induced in 70 out of 72 (97%) segments with abnormal perfusion. CONCLUSION: Perfusion abnormalities were observed in ab. 40% of patients with critical (≥ 50%) narrowing of artery affected by bridging and were mild, stress induced.

Radiation dose reduction with increasing utilization of prospective gating in 64-multidetector cardiac computed tomography angiography.

BACKGROUND: Medical radiation exposure is a major concern, and several methods have been proposed to reduce radiation doses in multidetector cardiac computed tomography (CT). OBJECTIVE: The purpose of this study was to review radiation doses of clinical cardiac CT performed at our center and to evaluate the effect of radiation dose reduction strategies on the median dose delivered to patients over time. METHODS: This study included 623 consecutive clinical patients (male, 58%) who were referred for imaging. The effective dose (mSv) was derived from the product of the dose-length-product (DLP) and a conversion coefficient for the chest (0.014). RESULTS: The median radiation dose of all patients was 3.0 mSv (interquartile range [IQR], 1.9-8.1 mSv). A significant difference was observed in radiation dose between the prospective (n = 384) and retrospective (n = 239) gating groups (2.0 vs 9.6 mSv; P < 0.0001). Compared with patients with coronary artery bypass grafting (CABG; n = 52), patients without CABG had significantly lower median radiation dose (prospective gating: 2.0 vs 3.4 mSv, P < 0.0001; retrospective gating: 9.3 vs 10.3 mSv, P < 0.0001). In patients with CABG, a significant difference was observed in radiation dose between prospective and retrospective gating (3.4 vs 10.3; P < 0.0001). The median radiation doses per month at our center decreased from 6.2 to 2.1 mSv over time with increasing use of prospective gating (≤91%). CONCLUSION: Radiation reduction techniques have led to progressive decreases in radiation exposure over time, primarily because of prospective gating.

[Prevalence and clinical significance of incidental cardiac findings in non-ECG-gated chest CT scans]. / Prävalenz und klinische Bedeutung inzidenteller Herzbefunde im nicht EKG-getriggerten Thorax-CT.

BACKGROUND: The purpose of this study was to evaluate the prevalence and clinical significance of incidental cardiac findings in non-ECG-gated chest CT. PATIENTS AND METHODS: Non-ECG-gated chest CT examinations of 300 patients were retrospectively analyzed for incidental cardiac findings. Subsequently, these findings were evaluated for their clinical relevance by a cardiologist. RESULTS: A total of 107 out of 300 examined patients had 174 incidental cardiac findings including coronary calcification (90), aortic/mitral valve calcification (42), iatrogenic changes (23), pericardial effusion (6), dilatation of the heart (4), myocardial changes (3), thrombus in the left ventricle (2), constrictive pericarditis (2) and atrial myxoma (1). Of the cardiac findings 51% were described in the written report and in 53 out of the 107 patients the cardiac findings were unknown. Newly detected incidental findings from 8 patients were rated as clinically significant: pericardial effusion (4), constrictive pericarditis (1), thrombus in the left ventricle (1), atrial myxoma (1) and dilatation of the heart (1). CONCLUSION: Incidental cardiac findings are frequent in non-ECG-gated chest CT and may have a high clinical relevance.

Prospective-gated cardiac micro-CT imaging of free-breathing mice using carbon nanotube field emission x-ray.

PURPOSE: Carbon nanotube (CNT) based field emission x-ray source technology has recently been investigated for diagnostic imaging applications because of its attractive characteristics including electronic programmability, fast switching, distributed source, and multiplexing. The purpose of this article is to demonstrate the potential of this technology for high-resolution prospective-gated cardiac micro-CT imaging. METHODS: A dynamic cone-beam micro-CT scanner was constructed using a rotating gantry, a stationary mouse bed, a flat-panel detector, and a sealed CNT based microfocus x-ray source. The compact single-beam CNT x-ray source was operated at 50 KVp and 2 mA anode current with 100 microm x 100 microm effective focal spot size. Using an intravenously administered iodinated blood-pool contrast agent, prospective cardiac and respiratory-gated micro-CT images of beating mouse hearts were obtained from ten anesthetized free-breathing mice in their natural position. Four-dimensional cardiac images were also obtained by gating the image acquisition to different phases in the cardiac cycle. RESULTS: High-resolution CT images of beating mouse hearts were obtained at 15 ms temporal resolution and 6.2 lp/mm spatial resolution at 10% of system MTF. The images were reconstructed at 76 microm isotropic voxel size. The data acquisition time for two cardiac phases was 44 +/- 9 min. The CT values observed within the ventricles and the ventricle wall were 455 +/- 49 and 120 +/- 48 HU, respectively. The entrance dose for the acquisition of a single phase of the cardiac cycle was 0.10 Gy. CONCLUSIONS: A high-resolution dynamic micro-CT scanner was developed from a compact CNT microfocus x-ray source and its feasibility for prospective-gated cardiac micro-CT imaging of free-breathing mice under their natural position was demonstrated.

Survey regarding the clinical practice of cardiac CT in Germany: indications, scanning technique and reporting.

PURPOSE: To obtain an overview of the current clinical practice of cardiac computed tomography (CT) in Germany. MATERIALS AND METHODS: A 30-item questionnaire was mailed to 149 providers of cardiac CT in Germany. The items asked about indications, scanning technique and reporting, data storage, and cost of the examination. RESULTS: Overall 45 questionnaires could be analyzed (30 %). The majority of centers (76 %, 34 of 45 centers) used CT scanners of the latest generation (at least 64 rows). The most common appropriate indications were exclusion of coronary artery disease (91 %, 41 / 45), coronary anomalies (80 %, 36 / 45), and follow-up after coronary artery bypass grafting (53 %, 24 / 45). Each center examined on average 243 +/- 310 patients in 2007 and the number of centers performing cardiac CT increased significantly in 2007 (p = 0.035) compared with the preceding year. Most used sublingual nitroglycerin (84 %, 38 / 45; median of 2 sprays = 0.8 mg) and/or a beta blocker (86 %, 39 / 44; median of 5 mg IV, median heart rate threshold: 70 beats/min). Many providers used ECG-triggered tube current modulation (65 %, 29 / 44) and/or adjusted the tube current to the body mass index or body weight (63 %, 28 / 44). A median slice thickness of 0.75 mm with a 0.5 mm increment and a 20 cm field-of-view was most commonly used. Source images in orthogonal planes (96 %, 43 / 45), curved MPRs (93 %, 42 / 45), and thin-slice MIPs (69 %, 31 / 45) were used most frequently for interpretation. Extracardiac structures were also evaluated by 84 % of the centers (38 / 45). The mean examination time was 16.2 min and reporting took an average of 28.8 min. CONCLUSION: Cardiac CT has rapidly become an established procedure with standards regarding indications, scanning technique, and reporting.