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Background: CAD-RADS was developed to standardize communication of per-patient maximal stenosis on coronary CT angiography (CCTA) and provide treatment recommendations and may impact primary prevention care and resource utilization. The authors sought to evaluate CAD-RADS adoption on preventive medical therapy and risk factor control amongst a mixed provider population., Methods: Statins, aspirin (ASA), systolic blood pressure and, when available, lipid panel changes were abstracted for 1796 total patients undergoing CCTA in the 12 months before (non-standard reporting, NSR, cohort) and after adoption of the CAD-RADS reporting template. Only initiation of a medication in a treatment naïve patient, escalation from baseline dose, or transition to a higher potency was considered an escalation/initiation in lipid therapy., Results: The CAD-RADS reporting template was utilized in 83.7% (751/897) of CCTAs after the CAD-RADS adoption period. After adjusting for any coronary artery disease (CAD) on CCTA, statin initiation/escalation was more commonly observed in the CAD-RADS cohort (aOR 1.46; 95%CI 1.12-1.90, p = 0.005), driven by higher rates of new statin initiation (aOR 1.79; 95%CI 1.23-2.58, p = 0.002). This resulted in a higher observed rates of total cholesterol improvement in the CAD-RADS cohort (58% vs 49%, p = 0.016). New ASA initiation was similar between reporting templates after adjustment for CAD on CCTA (aOR 1.40; 95%CI 0.97-2.02, p = 0.069). The ordering provider's specialty (cardiology vs non-cardiology) did not significantly impact the observed differences in initiation/escalation of statins and ASA (pinteraction = NS)., Conclusions: Adoption of CAD-RADS reporting was associated with increased utilization of preventive medications, regardless of ordering provider specialty., (Copyright © 2020 Society of Cardiovascular Computed Tomography. All rights reserved.)

Objectives: To assess the ability of multislice detector computed tomography (MDCT) to differentiate old versus acute/subacute vertebral fractures (VF) and to identify characteristic MDCT imaging signs., Methods: 74 consecutive patients demonstrated 192 VF that were classified as either acute/subacute or old based on magnetic resonance imaging, MDCT, and clinical information as reference standard. Classification as acute/subacute versus old fractures based on MDCT alone was evaluated on a Likert scale by 2 independent radiologists. Morphologic MDCT features of fractures, such as trabecular compaction or fracture line, were recorded. Receiver operating characteristic analyses and Cohen's κ were used to assess the discriminatory power of the MDCT and interrater agreement, respectively., Results: Out of all 192 VF, 148 fractures were acute/subacute and 44 were old according to the reference standard. Receiver operating characteristic analyses of sole MDCT assessment showed very good identification of acute/subacute VF, with areas under the curve of 0.854 and 0.861 for readers 1 and 2, respectively. When indeterminate findings were treated as acute/subacute fractures, sensitivity and specificity were 97.2% and 58.1% for reader 1 and 94.5% and 65.1% for reader 2. Interrater agreement regarding fracture age was good (weighted Cohen's κ = 0.607). Trabecular compression/callus distinct from the cortex (double compaction sign) was present in approximately half of acute/subacute VF and highly specific for acute/subacute VF (specificity = 93.2% and 88.6% for readers 1 and 2, respectively)., Conclusion: The acuity of VF can be assessed by MDCT alone with high sensitivity and in case of a double compaction sign with high specificity., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: The extent of aortic valve calcification is an important determinant of procedural success in transcatheter aortic valve implantation (TAVI). We sought to validate device landing zone calcium volume (DLZ-CV) measurements on contrast-enhanced multidetector computed tomography (MDCT) with non-contrast-enhanced scans as reference., Methods: We determined DLZ-CV in 141 patients undergoing transfemoral TAVI. Non-contrast-enhanced images were analyzed using a threshold of 130 HU as reference (DLZ-CV 130 ). For contrast-enhanced scans, we applied various thresholds including 450 HU (DLZ-CV 450 ), 850 HU (DLZ-CV 850 ), mean aortic attenuation (Atten Ao ) + 2 SD (DLZ-CV 2SD ), Atten Ao  + 4 SD (DLZ-CV 4SD ), Atten Ao  + 4 SD + 5 mm 3 volume filter (DLZ-CV 4SD+ ), and based on visual estimation (DLZ-CV vis ). We compared DLZ-CV values between patients with versus without paravalvular leak (PVL), and between patients with versus without post-dilatation stratified by the type of prosthesis., Results: All DLZ-CV measurements on contrast-enhanced scans significantly differed from DLZ-CV 130 (p < 0.001 for all comparisons). The best approximation to DLZ-CV 130 was achieved with DLZ-CV 4SD+ (508 mm 3 [332-772]; Pearson correlation: R = 0.87, p < 0.001; Bland-Altman: mean difference 1339 mm 3 [limits of agreement 79;2600]). Moreover, DLZ-CV 4SD+ allowed for discrimination of PVL ≥1° or the need for post-dilatation in patients receiving self-expanding prostheses. Procedural outcome using balloon-expandable prostheses was independent of DLZ-CV., Conclusion: Measurement of DLZ-CV using contrast-enhanced scans with unadjusted thresholds results in incorrect estimation of the calcium volume. The use of a scan-specific individual HU threshold including a volume filter (DLZ-CV 4SD+ ) provides the best approximation to the reference and allows for discrimination of PVL ≥ 1° in patients receiving the Acurate neo prosthesis., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Aims: To determine the diagnostic accuracy of semi-automatic quantitative metrics compared to expert reading for interpretation of computed tomography perfusion (CTP) imaging., Methods: The CORE320 multicenter diagnostic accuracy clinical study enrolled patients between 45 and 85 years of age who were clinically referred for invasive coronary angiography (ICA). Computed tomography angiography (CTA), CTP, single photon emission computed tomography (SPECT), and ICA images were interpreted manually in blinded core laboratories by two experienced readers. Additionally, eight quantitative CTP metrics as continuous values were computed semi-automatically from myocardial and blood attenuation and were combined using logistic regression to derive a final quantitative CTP metric score. For the reference standard, hemodynamically significant coronary artery disease (CAD) was defined as a quantitative ICA stenosis of 50% or greater and a corresponding perfusion defect by SPECT. Diagnostic accuracy was determined by area under the receiver operating characteristic curve (AUC)., Results: Of the total 377 included patients, 66% were male, median age was 62 (IQR: 56, 68) years, and 27% had prior myocardial infarction. In patient based analysis, the AUC (95% CI) for combined CTA-CTP expert reading and combined CTA-CTP semi-automatic quantitative metrics was 0.87(0.84-0.91) and 0.86 (0.83-0.9), respectively. In vessel based analyses the AUC's were 0.85 (0.82-0.88) and 0.84 (0.81-0.87), respectively. No significant difference in AUC was found between combined CTA-CTP expert reading and CTA-CTP semi-automatic quantitative metrics in patient based or vessel based analyses(p > 0.05 for all)., Conclusion: Combined CTA-CTP semi-automatic quantitative metrics is as accurate as CTA-CTP expert reading to detect hemodynamically significant CAD., (Copyright © 2018 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

There is an urgent need to develop new protocols to reduce radiation dose of coronary computed tomography angiography (CTA). The aim of this pilot study was to demonstrate the feasibility of an ultra-low dose CTA scanning., (Copyright © 2017. Published by Elsevier B.V.)

We evaluated the performance of a new volume computed tomographic (CT) scanner with regards to image quality and signal homogeneity. Twenty-four subjects were prospectively enrolled. Subjects had prior imaging with rate control. Quantitative analyses performed placing regions of interest in myocardium, blood pool, and aorta. Image quality and diagnostic interpretability were assessed using Likert scales. Median heart rate was 60 and 57 bpm for volume and 64-slice coronary CT angiography (P=.02). Improvement in homogeneity was demonstrated within myocardium (30% improvement), blood pool (73%), and aorta (73%). Improvement in image quality observed at per-patient/per-segment level. Pilot study confirmed improvements in signal homogeneity and diagnostic interpretability, despite imaging at higher heart rates., (Copyright © 2015. Published by Elsevier Inc.)

Purpose: To compare diagnostic-accuracy of prospective and retrospective-ECG-gated acquisition in 320-slice-CT for detecting coronary-artery stenosis in subjects with chronic-atrial-fibrillation (CAF) in a two-center study., Materials and Methods: 53 CAF subjects who underwent 320-slice-CT, and invasive-coronary-angiogram (ICA) within 6-months (43 male; 69 ± 9 years; CHADS2 score 2.2 ± 1.3; CHA2DS2-VASc score 3.5 ± 1.6) in the two institutes were analyzed. In Institute-1, prospective-ECG-gated acquisition was routinely performed (N=33). In Institute-2, retrospective-ECG-gated acquisition was routinely performed (N=20). CT and ICA data were transferred to the analysis center and were analyzed by cardiologists blinded to the clinical-data., Results: Prevalence of >50 and >75% on ICA was 79 and 61% in Institute-1, and 30 and 15% in Institute-2, respectively. In a patient-by-patient analysis, Institute-2 had higher negative-predictive-value (NPV) and accuracy of >75% stenosis on CT in predicting >75% stenosis on ICA. In a vessel-by-vessel analysis, there were no significant-differences of sensitivity, specificity, positive-predictive-value (PPV) and NPV of >50% stenosis on CT in predicting >50% stenosis on ICA between both institutes. But sensitivity, specificity, and NPV of >75% stenosis on CT in predicting >75% stenosis on ICA were significantly higher in Institute-2 than in Institute-1. This is mainly because of more severe coronary-artery disease including calcification in Institute-1; there might also have been an influence of differences in scanning and reconstruction methods., Conclusions: 320-slice-CT shows relatively high diagnostic-accuracy for the detection of significant coronary-artery stenosis compared with ICA even in CAF subjects, in a two-center analysis. Retrospective-ECG-gated acquisition in 320-slice-CT shows significantly higher diagnostic-accuracy than prospective-ECG-gated acquisition for detection of >75% coronary-artery stenosis., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Background: Multi-detector computed tomography angiography (MDCTA) is a promising method for risk assessment of patients with acute chest pain. However, its diagnostic performance in higher-risk patients has not been investigated in a large international multicenter trial. Therefore, in the present study we sought to estimate the diagnostic accuracy of MDCTA to detect significant coronary stenosis in patients with acute coronary syndrome (ACS)., Methods: Patients included in the CORE64 study were categorized as suspected-ACS or non-ACS based on clinical data. A 64-row coronary MDCTA was performed before invasive coronary angiography (ICA) and both exams were evaluated by blinded, independent core laboratories., Results: From 371 patients included, 94 were categorized as suspected ACS and 277 as non-ACS. Patient-based analysis showed an area under the receiver-operating-characteristic curve (AUC) for detecting ≥ 50% coronary stenosis of 0.95 (95% CI: 0.88-0.98) in ACS and 0.92 (95% CI: 0.88-0.95) in non-ACS group (P=0.29). The sensitivity, specificity, positive and negative predictive values of MDCTA were 0.90(0.80-0.96), 0.88(0.70-0.98), 0.95(0.87-0.99) and 0.77(0.58-0.90) in suspected ACS patients and 0.87(0.81-0.92), 0.86(0.79-0.92), 0.91(0.85-0.95) and 0.82(0.74-0.89) in non-ACS patients (P NS for all comparisons). The mean calcium scores (CS) were 282 ± 449 in suspected ACS and 435 ± 668 in non-ACS group. The accuracy of CS to detect significant coronary stenosis was only moderate and the absence or minimal coronary artery calcification could not exclude the presence of significant coronary stenosis, particularly in ACS patients., Conclusions: The diagnostic accuracy of MDCTA to detect significant coronary stenosis is high and comparable for both ACS and non-ACS patients., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Background: The aim of this study is to predict the risk of coronary-arteriosclerosis and prognosis in subjects with chronic-atrial-fibrillation (CAF) using the CHADS2 and CHA2DS2-VASc scores by 320-slice-CT and invasive-coronary-angiography (ICA) in a two-center-study., Methods: 53 CAF subjects who underwent 320-slice-CT and ICA within 6-months (43 male; 69 ± 9 years; CHADS2 score 2.2 ± 1.3; CHA2DS2-VASc score 3.5 ± 1.6) in the two-institutes were analyzed. CT and ICA data were transferred to the analysis-center and were analyzed by cardiologists., Results: Agatston-calcium-score and frequencies of the presence of various-kinds of plaques and >50% and >75% coronary artery stenosis were significantly higher in the subjects with CHA2DS2-VASc score ≥ 3 compared with those with score <3. However there were no-significant differences in the Agatston-calcium-score and frequencies of the presence of various-kinds of plaques and >50% and >75% coronary artery stenosis evaluated by 320-slice CT between the subjects with CHADS2 score ≥ 2 and <2. Frequency of >50% coronary artery stenosis by ICA was significantly higher in the subjects with CHA2DS2-VASc score ≥ 3 compared with those with score <3. However, there were no-significant differences in the frequencies of >50% and >75% coronary artery stenosis by ICA between the subjects with CHADS2 score ≥ 2 and <2. During a mean of 15.9 months, composite rate of cardiac death and heart failure did not differ between subjects with CHADS2 score ≥ 2 and score <2 and between subjects with CHA2DS2-VASc score ≥ 3 and score <3., Conclusions: The CHA2DS2-VASc score is a useful predictor of not prognosis but coronary-arteriosclerosis in subjects with CAF compared with CHADS2 score in this two-center-study., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Background: The complex anatomy of the aortic annulus warrants the use of three dimensional (3D) modalities for prosthesis sizing in transcatheter aortic valve implantation (TAVI). Multislice computed tomography (MSCT) has been used for this purpose, but its use may be restricted because of contrast administration. 3D transesophageal echocardiography (3D-TEE) lacks this limitation and data on comparison with MSCT is scarce. We compared 3D-TEE with MSCT for prosthesis sizing in TAVI., Methods: Aortic annulus diameters in the sagittal and coronal plane and annulus areas in 3D-TEE and MSCT were compared in 57 patients undergoing TAVI. Final prosthesis size was left at the operator's discretion and the agreement with 3D-TEE and MSCT was calculated., Results: Sagittal diameters on 3D-TEE and MSCT correlated well (r=.754, p<.0001) and means were comparable (22.3±2.1 vs. 22.5±2.3 mm; p=0.2; mean difference: -0.3 mm [-3.3-2.8]). On 3D-TEE, coronal diameter and annulus area were significantly smaller (p<.0001 for both) with moderate correlation (r=0.454 and r=0.592). Interobserver variability was comparable for both modalities. TAVI was successful in all patients with no severe post-procedural insufficiency. Final prosthesis size was best predicted by sagittal annulus diameters in 84% and 79% by 3D-TEE and MSCT, respectively. Agreement between both modalities was 77%., Conclusions: Annulus diameters and areas for pre-procedural TAVI assessment by 3D-TEE are significantly smaller than MSCT with exception of sagittal diameters. Using sagittal diameters, both modalities predicted well final prosthesis size and excellent procedural results were obtained. 3D-TEE can thus be a useful alternative in patients with contraindications to MSCT., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Introduction: F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) FDG PET is an established metabolic imaging technique to assess myocardial viability. Delayed iodinated contrast enhancement (DE) of myocardium on computed tomography (CT) has also been shown to be an anatomical marker of nonviable myocardium. A pilot study was undertaken to determine quantitative and qualitative agreement between metabolic viability imaging and scar imaging using FDG PET and multislice CT respectively., Methods: Fifteen patients with coronary artery disease and left ventricular dysfunction were recruited in the study. All patients underwent same day FDG PET and DECT to evaluate myocardial viability. The images were analyzed quantitatively and qualitatively using a 17 segment model., Results: DECT diagnosed viability in 57% (146/255) whilst PET in 51% (129/255) of segments. The per-segment agreement between DECT and FDG PET on qualitative analysis was 70% (Kappa: 0.40). The agreement in quantitative measurements between the two techniques for viability showed modest correlation [Pearson ρ: 0.63; P<0.0001] on scatter plot and the Passing-Bablok regression analysis. Higher agreement (70 vs 77%; P=0.051; Kappa: 0.40 vs 0.53) was obtained with quantitative compared to qualitative DECT., Conclusions: DECT may be useful in characterizing myocardial scar, and preliminary results correlate modestly with metabolic FDG PET, both qualitatively and quantitatively. Although in our study quantitative analysis offered superior agreement compared to qualitative with DECT, further studies are needed to determine its incremental value., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Background: Multidetector computed tomography (MDCT) is widely used for diagnosing acute aortic dissection (AAD). However, the diagnostic value of nonenhanced MDCT for AAD remains unknown. We evaluated the usefulness of nonenhanced 64-slice MDCT for ruling out AAD in patients presenting with chest or back pain., Methods: Of 107 patients with clinical suspicion of AAD who underwent MDCT, AAD was confirmed in 47 and ruled out in 60. Nonenhanced MDCT data of all patients were retrospectively assessed by 2 independent observers unaware of clinical information and contrast-enhanced MDCT data. The diagnostic performance of nonenhanced MDCT parameters to detect AAD was calculated., Results and Conclusion: Among the parameters, positive intimal flap, defined as the clear presence of a high-density membrane-like structure in the aorta on serial axial images, had a sensitivity of 87%, a specificity of 100%, a positive predictive value (PPV) of 100%, and a negative predictive value (NPV) of 91%, respectively. The addition of equivocal intimal flap, defined as the ambiguous presence of a high-density membrane-like structure in the aorta on at least one axial image, increased both the sensitivity and NPV to 96%. Furthermore, the combination of intimal flap (positive+equivocal or positive alone) and high-density area in the aorta showed the highest sensitivity (98%) and NPV (98%). Combination of the nonenhanced MDCT parameters intimal flap and high-density area in the aorta provides excellent sensitivity and NPV, suggesting that nonenhanced MDCT is an effective modality for ruling out AAD in patients with chest or back pain., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Background: In patients referred for aortic valve replacement (AVR) a pre-surgical assessment of coronary artery disease is mandatory to determine the possible need for additional coronary artery bypass grafting. The diagnostic accuracy of coronary computed tomography angiography (coronary CTA) was evaluated in patients with aortic valve stenosis referred for surgical AVR., Methods: Between March 2008 and March 2010 a total of 181 consecutive patients were included. All patients underwent pre-surgical coronary CTA (64- or 320-detector CT scanner) and invasive coronary angiography (ICA). The analyses were performed blinded to each other., Results: The mean ± SD age of the included patients was 71 ± 9 years and 59% were male. The prevalence of significant coronary artery stenosis >70% by ICA was 36%. Average heart rate during coronary CTA was 65 ± 16 b pm. In a patient based analysis 94% of the patients (171/181) were considered fully evaluable. Coronary CTA had a sensitivity of 68%, a specificity of 91%, a positive predictive value of 81%, and a negative predictive value of 83%. Advanced age, obstructive lung disease, NYHA function class III/IV, and high Agatston score were found to be significantly associated with disagreement between ICA and coronary CTA in univariate analysis., Conclusion: In patients with aortic valve stenosis referred for surgical AVR the diagnostic accuracy of coronary CTA to identify significant coronary artery disease is moderate. Coronary CTA may be used successfully in a subset of patients with low age, no chronic obstructive lung disease, NYHA function class

Background: Based on recent clinical data, an imaging strategy of identifying proximal coronary disease allows further management decisions in patients with stable angina pectoris. We aimed to compare diagnostic accuracy of non-contrast fast steady-state (FIESTA) magnetic resonance angiography (MRA) with 64-multidetector computed tomographic angiography (CTA), using conventional coronary angiography (CA) as the reference standard., Methods: Thirty patients with suspected coronary artery disease consented to participate in an institutional review board-approved protocol. Coronary MRA was performed at 1.5 T using a respiratory navigator and electrocardiogram-gated three-dimensional FIESTA pulse sequence. CTA images were acquired using a 64-multidetector computed tomographic scanner, using beta blockade to reduce the heart rate to less than 70 bpm. Coronary luminal stenosis >50% was identified. Plaques were classified as non-calcified, mixed, or calcified on CTA, and as high-, intermediate-, or low-signal on FIESTA MRA., Results: Compared to CA, the sensitivity, specificity, and overall accuracy for detection of >50% proximal coronary stenoses were 83.0%, 86.9%, and 86.1% for MRA and 85.1%, 87.2%, and 86.8% for CTA, respectively. For the 24 calcified stenoses, MRA corrected 16 segments that overestimated on CTA and MRA had an accuracy of 75% in evaluating calcified plaques., Conclusions: High-resolution three-dimensional FIESTA MRA and CTA have a similar accuracy in detecting proximal coronary stenosis. The clinical impact of identification of proximal disease in patients with stable CAD needs to be examined in future studies., (Copyright © 2012. Published by Elsevier Ireland Ltd.)

Objective: Assessment of coronary artery calcification is increasingly used for cardiovascular risk stratification. We evaluated the reliability of calcium-scoring results using a novel iterative reconstruction algorithm (ASIR) on a high-definition 64-slice CT scanner, as such data is lacking., Methods and Results: In 50 consecutive patients Agatston scores, calcium mass and volume score were assessed. Comparisons were performed between groups using filtered back projection (FBP) and 20-100% ASIR algorithms. Calcium score was measured in the coronary arteries, signal and noise were measured in the aortic root and left ventricle. In comparison with FBP, use of 20%, 40%, 60%, 80%, and 100% ASIR resulted in reduced image noise between groups (7.7%, 18.8%, 27.9%, 39.86%, and 48.56%, respectively; p<0.001) without difference in signal (p=0.60). With ASIR algorithms Agatston coronary calcium scoring significantly decreased compared with FBP algorithms (837.3 ± 130.3; 802.2 ± 124.9, 771.5 ± 120.7; 744.7 ± 116.8, 724.5 ± 114.2, and 709.2 ± 112.3 for 0%, 20%, 40%, 60%, 80%, and 100% ASIR, respectively, p<0.001). Volumetric score decreased in a similar manner (p<0.001) while calcium mass remained unchanged. Mean effective radiation dose was 0.81 ± 0.08 mSv., Conclusion: ASIR results in image noise reduction. However, ASIR image reconstruction techniques for HDCT scans decrease Agatston coronary calcium scores. Thus, one needs to be aware of significant changes of the scoring results caused by different reconstruction methods., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Background: The aims of this study are to evaluate the accuracy of low dose multidetector computed tomography coronary angiography (MDCT) versus invasive coronary angiography (ICA) in ruling out CAD in patients with mitral valve prolapse and severe mitral regurgitation (MVP) before cardiac surgery and to compare the overall effective radiation dose (ED) and cost of a diagnostic approach in which conventional ICA should be performed only in patients with significant CAD as detected by MDCT., Methods: Eighty patients with MVP and without history of CAD were randomized to MDCT (Group 1) or ICA (Group 2) to rule out CAD before surgery. However, ICA was also performed as gold standard reference in Group 1 to test the diagnostic accuracy of MDCT. A diagnostic work-up A in whom all patients underwent low-dose MDCT as initial diagnostic test and those with positive findings were referred for ICA was compared with work-up B in which all patients were referred for ICA according to the standard of care in terms of ED and cost., Results: The two groups were homogeneous in terms of gender, age and body mass index. The overall feasibility and accuracy in a patient-based model were 99% and 93%, respectively. The overall ED and costs were significantly lower in diagnostic work-up A compared to diagnostic work-up B., Conclusions: The accuracy of low dose MDCT for ruling out the presence of significant CAD in patients undergoing elective valve surgery for mitral valve prolapse is excellent with a reduction of overall radiation dose exposure and costs., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To evaluate the diagnostic accuracy of 320-slice CT for detection of significant coronary artery stenosis in patients with various heart rates (HR) and heart rhythms, including tachycardia and chronic atrial-fibrillation (CAF) compared with conventional-coronary-angiography (CAG)., Materials and Methods: One-hundred-six consecutive patients underwent both 320-slice CT and CAG within 3 months (normal-sinus-rhythm [NSR] 91.5%, CAF 8.5%, mean HR 65 ± 15 beats/min). There were no cardiac events between the 2 procedures. Patients were divided in 2 groups: Group 1 (HR <65 with NSR at CT scan, n=62), and Group 2 (HR >64 with NSR or heart rhythm irregularities at CT scan, n=44). Patients with >50% or >75% luminal stenosis on CT were compared with those with >50% or >75% stenosis on CAG, respectively., Results: In a segment-by-segment analysis, in all patients, sensitivity, specificity, positive (PPV) and negative predictive value (NPV) of >50% stenosis on CT for predicting >50% stenosis on CAG were 69, 98, 78, and 97%, respectively, and those of >75% stenosis on CT for predicting >75% stenosis on CAG were 78, 98, 64, and 99%, respectively. Sensitivity, specificity, PPV, and NPV of >50% and 75% stenosis on CT for predicting >50% and >75% stenosis, respectively, on CAG were comparable. Diagnostic accuracy was essentially the same in both groups., Conclusion: 320-slice CT had high diagnostic accuracy for the detection of significant coronary artery stenosis compared with CAG. Even though the numbers were small, patients with high HR or heart rhythm irregularities might have essentially equivalent results to those with low HR with NSR., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Background: The papillary and trabecular muscles constitute a significant percentage of left ventricular mass and volume. The influence of the papillary and trabecular muscles on left ventricular parameters has not been described with multidetector CT angiography., Objective: The aims of this study are (1) to derive reference values for left ventricular volumetric parameters both including and excluding the papillary and trabecular muscles and (2) to establish the optimal segmentation method for measuring these values., Methods: A total of 179 subjects (mean age, 55.4 ± 9 years; 102 women) without heart disease and at low risk of cardiovascular disease who underwent CT angiography were selected. Left ventricular volumes, myocardial volume, and ejection fraction were measured with epicardial and 2 endocardial trace methods, including and excluding trace for the papillary and trabecular muscles. Values of all parameters obtained by both endocardial trace methods were compared., Results: Significant difference between both trace groups for all parameters on both sexes was found (P < .001). Significant differences in precision error of remeasurement were found in the including trace (3.6%) compared with the excluding trace (4.7%; P < .05) and in the epicardial trace (2.2%) compared with both endocardial traces (P < .001)., Conclusion: The left ventricular parameters measured by CT angiography were influenced significantly by the trace method by including or excluding the papillary and trabecular muscles. The dual-standard reference values of left ventricular parameters were established, and the optimal segmentation methods were definite in considering the heart size and image quality studied with retrospective and prospective CT angiography., (Copyright © 2013 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Introduction: Gray level is the range of shades of gray in the pixels, representing the x-ray attenuation coefficient that allows for tissue density assessments in computed tomography (CT). An in-vitro study was performed to investigate the relationship between computed gray levels in 3 cone-beam CT (CBCT) scanners and 1 multislice spiral CT device using 5 software programs., Methods: Six materials (air, water, wax, acrylic, plaster, and gutta-percha) were scanned with the CBCT and CT scanners, and the computed gray levels for each material at predetermined points were measured with OsiriX Medical Imaging software (Geneva, Switzerland), OnDemand3D (CyberMed International, Seoul, Korea), E-Film (Merge Healthcare, Milwaukee, Wis), Dolphin Imaging (Dolphin Imaging & Management Solutions, Chatsworth, Calif), and InVivo Dental Software (Anatomage, San Jose, Calif). The repeatability of these measurements was calculated with intraclass correlation coefficients, and the gray levels were averaged to represent each material. Repeated analysis of variance tests were used to assess the differences in gray levels among scanners and materials., Results: There were no differences in mean gray levels with the different software programs. There were significant differences in gray levels between scanners for each material evaluated (P <0.001)., Conclusions: The software programs were reliable and had no influence on the CT and CBCT gray level measurements. However, the gray levels might have discrepancies when different CT and CBCT scanners are used. Therefore, caution is essential when interpreting or evaluating CBCT images because of the significant differences in gray levels between different CBCT scanners, and between CBCT and CT values., (Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Background: Although numerous trials have demonstrated the diagnostic accuracy of coronary artery calcium (CAC) scanning for prediction of obstructive disease, virtually all studies have been performed using Electron Beam CT (EBCT). We evaluated the diagnostic accuracy of CAC by 64-row CT to detect obstructive coronary stenosis compared to quantitative coronary angiography (QCA) in the ACCURACY multicenter trial., Methods: 16 sites prospectively enrolled 230 patients (pts) [59.5% males, 57yrs] with chest pain referred for invasive coronary angiography (ICA). Pts underwent CAC scan and CT angiography prior to ICA. Total CAC scores were correlated with angiographically documented stenoses using common cutpoints of CAC >0, >100 and >400. Significant obstructive disease was defined as >50% luminal stenosis by QCA., Results: The per-patient accuracy of CAC by 64-row CT compared to QCA demonstrates a high sensitivity and low specificity for the presence of obstructive disease (>50% stenosis on QCA). With CAC >0, >100 and >400, the sensitivities to predict stenosis were 98%, 88%, and 60%, whereas the specificities were 42%, 71%, and 88%, respectively., Conclusions: Most previous CAC studies have focused on the fact that significant calcium places patients into a higher risk group in terms of future events, and should lead to more aggressive treatment with preventative therapies. This prospective multicenter results comparing 64-row CAC to QCA demonstrate that CAC using 64-row CT scanner, similar to previously published reports using EBCT, is highly sensitive and moderately specific test to predict significant coronary artery stenosis. The presence of abnormal levels of calcium may place patients into a higher risk group in terms of future events, and lead to more aggressive treatment with preventative therapies. However, the detection of calcium does not always help with a clinical diagnosis particularly in the presence of diffuse moderate coronary atheroma. Whether this information is complementary to CTA data remains to be validated., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Background: Most studies have investigated the diagnostic accuracy of 64-slice multi-detector computed tomography (MDCT) to detect coronary artery stent patency by using conventional coronary angiography (CCA) as the reference standard. In this study, we compared the diagnostic accuracy of MDCT and CCA by using intravascular ultrasonography (IVUS) as the reference standard., Methods: Forty-six patients with previously implanted coronary artery stents (n=87) underwent MDCT followed by CCA and IVUS within 24h. Sensitivities, specificities, positive predictive values (PPV) and negative predictive values (NPV) of MDCT and CCA for detecting or excluding in-stent diameter restenosis (ISDR) by using in-stent area restenosis (ISAR) and minimal luminal area (MLA) ≤4.0 mm(2) of IVUS as the reference standard were determined., Results: Eight stents (9%) were judged non-evaluable using MDCT for the detection of ISDR. ISDR was detected in 28% (22/79) of the evaluable stents using CCA. When ISAR was detected using IVUS, the sensitivity, specificity, PPV, and NPV for ISDR detection by using MDCT were 71%, 96%, 91% and 86%, and the corresponding values for CCA were 64%, 96%, 90% and 83%. When MLA ≤4.0mm(2) was detected using IVUS, the sensitivity, specificity, PPV, and NPV for ISDR detection by using MDCT were 87%, 96%, 91% and 95%, and for CCA were 78%, 96%, 90% and 92%., Conclusions: When ISAR with MLA ≤4.0 mm(2)was detected on IVUS, CCA and MDCT had similar diagnostic accuracies for ISDR detection. High specificity and NPV make 64-slice MDCT a reliable non-invasive method for excluding ISDR., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

We conducted a meta-analysis evaluating the critical ratio between effective radiation dose (ED), feasibility (Fe) and diagnostic accuracy (Ac) of multidetector computed tomography (MDCT) for the detection of significant coronary artery disease. By using our predetermined criteria, we selected human studies published in English in which the ED and raw data of Ac vs. invasive coronary angiography in a segment based model were specified. Data from 31 studies including 3661 patients (mean age 61.9 ± 4.5 years, heart rate 62.5 ± 6.7 bpm) and 50,236 coronary artery segments were analysed and are reported. Overall, Fe, sensitivity, specificity, negative predictive value, positive predictive value, Ac and ED were 95%, 90%, 96%, 99%, 69%, 95% and 10.4 ± 5.4 mSv, respectively. Multivariate analysis showed that prospective ECG-gating (-8.8 mSv CI95% -13.4 to -4.3 mSv, p=0.001), dual-source (-3.7 mSv CI95% -7.9 to 0 mSv, p=0.05) and BMI-adapted scanning protocols (-4.5 mSv CI95% -8.7 to -2.7 mSv, p=0.03) were independent predictors of ED reduction. In patients with low heart rate, the best compromise between ED, Fe and Ac (2.5 mSv, 97% and 98%, respectively) was obtained combining prospective ECG-gating and BMI-adapted scanning protocols, while in patients with high heart rate the strategy associated with the best results (10 mSv, 98% and 97%, respectively) was the use of dual-source MDCT with retrospective ECG gating and modulation dose. In conclusion, careful selection of CT scanning protocols according to the patient's characteristics is critical for keeping the radiation exposure "as low as reasonably achievable" (ALARA) without impairing Fe and Ac., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Background: Multidetector computed tomography (MDCT) is useful in evaluation of coronary artery bypass graft (CABG). However, radiation exposure is a reason for concern. We compared diagnostic performance and effective dose of a new dedicated post-processing reconstruction algorithm with BMI-adapted scanning protocol (MDCT-XTe) vs. standard prospective ECG-triggering protocol (MDCT-XT) and retrospective ECG-triggering (MDCT-Helical), compared to invasive coronary angiography (ICA), in the assessment of grafts and nongrafted or distal runoff coronary arteries., Methods: One hundred and nineteen patients with 277 grafts were randomized to Group 1 based on BMI-adapted scanning protocol with prospective ECG-triggering (40 patients), Group 2 with prospective ECG-triggering (39 patients) and Group 3 (40 patients) with retrospective ECG-triggering. Data were acquired using 64-slice MDCT., Results: MDCT correctly assessed the patency of all CABG in 3 groups. After comparison with ICA, MDCT was able to correctly detect the occlusion or stenosis of CABG in all groups, with the exception of one case of Group 3. In Group 3 sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CABG evaluation were 100%, 98.4%, 96.7%, 100% and 98.9%, respectively. In Groups 1 and 2 the diagnostic accuracy of CABG evaluation was 100%. Effective radiation dose was 3.5±1.4mSv in Group 1 vs. 7.4±2.6mSv in Group 2 vs. 27.8±9.4mSv in Group 3., Conclusions: Our results indicated that MDCT-XTe and MDCT-XT have a diagnostic performance in the evaluation of CABG similar to MDCT-Helical, with a significant reduction of radiation exposure, specially for MDCT-XTe., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To evaluate efficacy and reproducibility of 320-slice computed tomography (CT) for measuring left atrial (LA) maximum (LAVmax) and minimum volume (LAVmin) during the cardiac cycle, we compared CT with three- and two-dimensional (3D and 2D) transthoracic echocardiogram (TTE)., Materials and Methods: LAVmax and LAVmin (ml), and LA ejection fraction (LAEF) (%) were assessed in 22 consecutive subjects (15 males, 59.5 ± 15.1 years) using retrospective electrocardiogram gated 320-slice CT (Aquilion One, Toshiba Medical) and 3D-TTE (IE-33, Phillips). LAVmax and LAVmin were selected from the time volume curve. LAEF was calculated as (LAVmax-LAVmin)/LAVmax×100(%)., Results: Mean ± standard deviation (SD) of LAVmax and LAV min were significantly larger by CT than 3D-TTE or 2D-TTE (both P<0.01). LAEF was 25.3 ± 13.1% by CT, 30.2 ± 6.8% by 3D-TTE (P=NS) and 33.9 ± 8.9% by 2D-TTE (P<0.05). The correlation coefficients (CCs) between CT and 3D-TTE in LAVmax, LAmin, and LAEF were 0.64, 0.68 and 0.57, respectively. Mean difference ± 1.96SD of LAVmax, LAVmin and LAEF by Bland and Altman analysis calculated from CT minus 3D-TTE were 48.8 ± 59.1 ml, 41.1 ± 63.2 ml, and -4.9 ± 21.1%, respectively. The CCs and mean difference ± 1.96SD between CT and 2D-TTE had similar tendencies. The CCs of interobserver variation were (for CT, 3D-TTE, 2D-TTE, respectively): 0.90, 0.95 and 0.94 (LAVmax), 0.97 and 0.97 and 0.93 (LAVmin), and 0.64, 0.77 and 0.34 (LAEF)., Conclusions: 320-slice CT enables direct LAV measurements and has high reproducibility and positive correlation with 3D and 2D TTE. Absolute value of LAV by CT was larger than that by 3D and 2D TTE., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)