Conventional Autopsy versus Minimally Invasive Autopsy with Postmortem MRI, CT, and CT-guided Biopsy: Comparison of Diagnostic Performance.

Purpose To compare the diagnostic performance of minimally invasive autopsy with that of conventional autopsy. Materials and Methods For this prospective, single-center, cross-sectional study in an academic hospital, 295 of 2197 adult cadavers (mean age: 65 years [range, 18-99 years]; age range of male cadavers: 18-99 years; age range of female cadavers: 18-98 years) who died from 2012 through 2014 underwent conventional autopsy. Family consent for minimally invasive autopsy was obtained for 139 of the 295 cadavers; 99 of those 139 cadavers were included in this study. Those involved in minimally invasive autopsy and conventional autopsy were blinded to each other's findings. The minimally invasive autopsy procedure combined postmortem MRI, CT, and CT-guided biopsy of main organs and pathologic lesions. The primary outcome measure was performance of minimally invasive autopsy and conventional autopsy in establishing immediate cause of death, as compared with consensus cause of death. The secondary outcome measures were diagnostic yield of minimally invasive autopsy and conventional autopsy for all, major, and grouped major diagnoses; frequency of clinically unsuspected findings; and percentage of answered clinical questions. Results Cause of death determined with minimally invasive autopsy and conventional autopsy agreed in 91 of the 99 cadavers (92%). Agreement with consensus cause of death occurred in 96 of 99 cadavers (97%) with minimally invasive autopsy and in 94 of 99 cadavers (95%) with conventional autopsy (P = .73). All 288 grouped major diagnoses were related to consensus cause of death. Minimally invasive autopsy enabled diagnosis of 259 of them (90%) and conventional autopsy 224 (78%); 200 (69%) were found with both methods. At clinical examination, the cause of death was not suspected in 17 of the 99 cadavers (17%), and 124 of 288 grouped major diagnoses (43%) were not established. There were 219 additional clinical questions; 189 (86%) were answered with minimally invasive autopsy and 182 (83%) were answered with conventional autopsy (P = .35). Conclusion The performance of minimally invasive autopsy in the detection of cause of death was similar to that of conventional autopsy; however, minimally invasive autopsy has a higher yield of diagnoses. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Krombach in this issue.

Non-invasive or minimally invasive autopsy compared to conventional autopsy of suspected natural deaths in adults: a systematic review.

OBJECTIVES: Autopsies are used for healthcare quality control and improving medical knowledge. Because autopsy rates are declining worldwide, various non-invasive or minimally invasive autopsy methods are now being developed. To investigate whether these might replace the invasive autopsies conventionally performed in naturally deceased adults, we systematically reviewed original prospective validation studies. MATERIALS AND METHODS: We searched six databases. Two reviewers independently selected articles and extracted data. Methods and patient groups were too heterogeneous for meaningful meta-analysis of outcomes. RESULTS: Sixteen of 1538 articles met our inclusion criteria. Eight studies used a blinded comparison; ten included less than 30 appropriate cases. Thirteen studies used radiological imaging (seven dealt solely with non-invasive procedures), two thoracoscopy and laparoscopy, and one sampling without imaging. Combining CT and MR was the best non-invasive method (agreement for cause of death: 70 %, 95%CI: 62.6; 76.4), but minimally invasive methods surpassed non-invasive methods. The highest sensitivity for cause of death (90.9 %, 95%CI: 74.5; 97.6, suspected duplicates excluded) was achieved in recent studies combining CT, CT-angiography and biopsies. CONCLUSION: Minimally invasive autopsies including biopsies performed best. To establish a feasible alternative to conventional autopsy and to increase consent to post-mortem investigations, further research in larger study groups is needed. KEY POINTS: • Health care quality control benefits from clinical feedback provided by (alternative) autopsies. • So far, sixteen studies investigated alternative autopsy methods for naturally deceased adults. • Thirteen studies used radiological imaging modalities, eight tissue biopsies, and three CT-angiography. • Combined CT, CT-angiography and biopsies were most sensitive diagnosing cause of death.

Restriction of the referral of patients with stable angina for CT coronary angiography by clinical evaluation and calcium score: impact on clinical decision making.

OBJECTIVE: To investigate the value of the calcium score (CaSc) plus clinical evaluation to restrict referral for CT coronary angiography (CTCA) by reducing the number of patients with an intermediate probability of coronary artery disease (CAD). METHODS: We retrospectively included 1,975 symptomatic stable patients who underwent clinical evaluation and CaSc calculation and CTCA or invasive coronary coronary angiography (ICA). The outcome was obstructive CAD (≥50 % diameter narrowing) assessed by ICA or CTCA in the absence of ICA. We investigated two models: (1) clinical evaluation consisting of chest pain typicality, gender, age, risk factors and ECG and (2) clinical evaluation with CaSc. Discrimination of the two models was compared. The stepwise reclassification of patients with an intermediate probability of CAD (10-90 %) after clinical evaluation followed by clinical evaluation with CaSc was assessed by clinical net reclassification improvement (NRI). RESULTS: Discrimination of CAD was significantly improved by adding CaSc to the clinical evaluation (AUC: 0.80 vs. 0.89, P < 0.001). CaSc and CTCA could be avoided in 9 % using model 1 and an additional 29 % of CTCAs could be avoided using model 2. Clinical NRI was 57 %. CONCLUSION: CaSc plus clinical evaluation may be useful in restricting further referral for CTCA by 38 % in symptomatic stable patients with suspected CAD. KEY POINTS: • CT calcium scores (CaSc) could proiritise referrals for CT coronary angiography (CTCA) • CaSc provides an incremental discriminatory value of CAD compared with clinical evaluation • Risk stratification is better when clinical evaluation is combined with CaSc • Appropriate use of clinical evaluation and CaSc helps avoid unnecessary CTCA referrals.

Diagnostic accuracy of 128-slice dual-source CT coronary angiography: a randomized comparison of different acquisition protocols.

OBJECTIVES: To compare the diagnostic performance and radiation exposure of 128-slice dual-source CT coronary angiography (CTCA) protocols to detect coronary stenosis with more than 50 % lumen obstruction. METHODS: We prospectively included 459 symptomatic patients referred for CTCA. Patients were randomized between high-pitch spiral vs. narrow-window sequential CTCA protocols (heart rate below 65 bpm, group A), or between wide-window sequential vs. retrospective spiral protocols (heart rate above 65 bpm, group B). Diagnostic performance of CTCA was compared with quantitative coronary angiography in 267 patients. RESULTS: In group A (231 patients, 146 men, mean heart rate 58 ± 7 bpm), high-pitch spiral CTCA yielded a lower per-segment sensitivity compared to sequential CTCA (89 % vs. 97 %, P = 0.01). Specificity, PPV and NPV were comparable (95 %, 62 %, 99 % vs. 96 %, 73 %, 100 %, P > 0.05) but radiation dose was lower (1.16 ± 0.60 vs. 3.82 ± 1.65 mSv, P < 0.001). In group B (228 patients, 132 men, mean heart rate 75 ± 11 bpm), per-segment sensitivity, specificity, PPV and NPV were comparable (94 %, 95 %, 67 %, 99 % vs. 92 %, 95 %, 66 %, 99 %, P > 0.05). Radiation dose of sequential CTCA was lower compared to retrospective CTCA (6.12 ± 2.58 vs. 8.13 ± 4.52 mSv, P < 0.001). Diagnostic performance was comparable in both groups. CONCLUSION: Sequential CTCA should be used in patients with regular heart rates using 128-slice dual-source CT, providing optimal diagnostic accuracy with as low as reasonably achievable (ALARA) radiation dose.

Validation of a Three-Dimensional Computed Tomography Reconstruction Tool for Aortic Valve Calcium Quantification.

Background: Aortic valve calcification correlates with the severity of aortic valve stenosis and a high calcium score is associated with conduction disturbances and paravalvular leakage after transcatheter aortic valve replacement. The 3mensio Structural Heart is a semiautomated software package to facilitate aortic root analysis by multislice computed tomography.The aim of the contemporary study is to validate a semiautomated calcium quantification scoring tool with a conventional manual calcium quantification tool. Methods: Fifty randomly selected patients who underwent multislice computed tomography for preprocedural planning were retrospectively selected to compare the semiautomated aortic valve Agatston calcium score by 3mensio with the manually obtained score using IntelliSpace Portal as standard reference. Results: Patients had a mean age of 76.7 ± 7.4 years and 60% were male. The median Agatston score was 3390 [interquartile range 1877-4509] with 3mensio and 3434 [interquartile range 1839-4620] with IntelliSpace.The mean difference was -0.18 [95% confidence interval (CI) -53.8 to 53.4]. The intraclass correlation coefficient between the Agatston scores using IntelliSpace and 3mensio showed an excellent correlation of 0.995 [95% CI 0.992-0.997], p ≤ 0.001. The interobserver and intraobserver variability was 0.993 ([95% CI 0.961-0.998], p ≤ 0.001) and 0.995([95%CI 0.981-0.999], p = <0.001), respectively. Conclusions: The semiautomated calcium quantification module in 3mensio Structural Heart highly correlated with a conventional manual calcium scoring tool.

Computed tomography coronary angiography accuracy in women and men at low to intermediate risk of coronary artery disease.

OBJECTIVES: To investigate the diagnostic accuracy of CT coronary angiography (CTCA) in women at low to intermediate pre-test probability of coronary artery disease (CAD) compared with men. METHODS: In this retrospective study we included symptomatic patients with low to intermediate risk who underwent both invasive coronary angiography and CTCA. Exclusion criteria were previous revascularisation or myocardial infarction. The pre-test probability of CAD was estimated using the Duke risk score. Thresholds of less than 30 % and 30-90 % were used for determining low and intermediate risk, respectively. The diagnostic accuracy of CTCA in detecting obstructive CAD (≥50 % lumen diameter narrowing) was calculated on patient level. P < 0.05 was considered significant. RESULTS: A total of 570 patients (46 % women [262/570]) were included and stratified as low (women 73 % [80/109]) and intermediate risk (women 39 % [182/461]). Sensitivity, specificity, PPV and NPV were not significantly different in and between women and men at low and intermediate risk. For women vs. men at low risk they were 97 % vs. 100 %, 79 % vs. 90 %, 80 % vs. 80 % and 97 % vs. 100 %, respectively. For intermediate risk they were 99 % vs. 99 %, 72 % vs. 83 %, 88 % vs. 93 % and 98 % vs. 99 %, respectively. CONCLUSION: CTCA has similar diagnostic accuracy in women and men at low and intermediate risk. KEY POINTS : • Coronary artery disease (CAD) is increasingly investigated by computed tomography angiography (CTCA). • CAD detection or exclusion by CTCA is not different between sexes. • CTCA diagnostic accuracy was similar between low and intermediate risk sex-specific-groups. • CTCA rarely misses obstructive CAD in low-intermediate risk women and men. • CAD yield by invasive coronary angiography after positive CTCA is similar between sex-risk-specific groups.

Image quality and radiation exposure using different low-dose scan protocols in dual-source CT coronary angiography: randomized study.

PURPOSE: To compare image quality, radiation dose, and their relationship with heart rate of computed tomographic (CT) coronary angiographic scan protocols by using a 128-section dual-source CT scanner. MATERIALS AND METHODS: Institutional review board approved the study; all patients gave informed consent. Two hundred seventy-two patients (175 men, 97 women; mean ages, 58 and 59 years, respectively) referred for CT coronary angiography were categorized according to heart rate: less than 65 beats per minute (group A) and 65 beats per minute or greater (group B). Patients were randomized to undergo prospective high-pitch spiral scanning and narrow-window prospective sequential scanning in group A (n = 160) or wide-window prospective sequential scanning and retrospective spiral scanning in group B (n = 112). Image quality was graded (1 = nondiagnostic; 2 = artifacts present, diagnostic; 3 = no artifacts) and compared (Mann-Whitney and Student t tests). RESULTS: In group A, mean image quality grade was significantly lower with high-pitch spiral versus sequential scanning (2.67 ± 0.38 [standard deviation] vs 2.86 ± 0.21; P < .001). In a subpopulation (heart rate, <55 beats per minute), mean image quality grade was similar (2.81 ± 0.30 vs 2.94 ± 0.08; P = .35). In group B, image quality grade was comparable between sequential and retrospective spiral scanning (2.81 ± 0.28 vs 2.80 ± 0.38; P = .54). Mean estimated radiation dose was significantly lower (high-pitch spiral vs sequential scanning) in group A (for 100 kV, 0.81 mSv ± 0.30 vs 2.74 mSv ± 1.14 [P < .001]; for 120 kV, 1.65 mSv ± 0.69 vs 4.21 mSv ± 1.20 [P < .001]) and in group B (sequential vs retrospective spiral scanning) (for 100 kV, 4.07 mSv ± 1.07 vs 5.54 mSv ± 1.76 [P = .02]; for 120 kV, 7.50 mSv ± 1.79 vs 9.83 mSv ± 3.49 [P = .1]). CONCLUSION: A high-pitch spiral CT coronary angiographic protocol should be applied in patients with regular and low (<55 beats per minute) heart rates; a sequential protocol is preferred in all others.

Assessment of coronary artery disease and calcified coronary plaque burden by computed tomography in patients with and without diabetes mellitus.

PURPOSE: To compare the coronary atherosclerotic burden in patients with and without type-2 diabetes using CT Coronary Angiography (CTCA). METHODS AND MATERIALS: 147 diabetic (mean age: 65 ± 10 years; male: 89) and 979 nondiabetic patients (mean age: 61 ± 13 years; male: 567) without a history of coronary artery disease (CAD) underwent CTCA. The per-patient number of diseased coronary segments was determined and each diseased segment was classified as showing obstructive lesion (luminal narrowing >50%) or not. Coronary calcium scoring (CCS) was assessed too. RESULTS: Diabetics showed a higher number of diseased segments (4.1 ± 4.2 vs. 2.1 ± 3.0; p < 0.0001); a higher rate of CCS > 400 (p < 0.001), obstructive CAD (37% vs. 18% of patients; p < 0.0001), and fewer normal coronary arteries (20% vs. 42%; p < 0.0001), as compared to nondiabetics. The percentage of patients with obstructive CAD paralleled increasing CCS in both groups. Diabetics with CCS ≤ 10 had a higher prevalence of coronary plaque (39.6% vs. 24.5%, p = 0.003) and obstructive CAD (12.5% vs. 3.8%, p = 0.01). Among patients with CCS ≤ 10 all diabetics with obstructive CAD had a zero CCS and one patient was asymptomatic. CONCLUSIONS: Diabetes was associated with higher coronary plaque burden. The present study demonstrates that the absence of coronary calcification does not exclude obstructive CAD especially in diabetics.

Non-invasive diagnostic workup of patients with suspected stable angina by combined computed tomography coronary angiography and magnetic resonance perfusion imaging.

BACKGROUND: To evaluate additional adenosine magnetic resonance perfusion (MRP) imaging in the diagnostic workup of patients with suspected stable angina with computed tomography coronary angiography (CTCA) as first-line diagnostic modality. METHODS AND RESULTS: Two hundred and thirty symptomatic patients (male, 52%; age, 56 year) with suspected stable angina underwent CTCA. In patients with a stenosis of >50% as visually assessed, MRP was performed and the quantitative myocardial perfusion reserve index (MPRI) was calculated. Coronary flow reserve (CFR) using invasive coronary flow measurements served as the standard of reference. CTCA showed non-significant CAD in 151/230 (66%) patients and significant CAD in 79/230 patients (34%), of whom 50 subsequently underwent MRP and CFR. MRP showed reduced perfusion in 32 patients (64%), which was confirmed by CFR in 27 (84%). All 18 cases of normal MRP (36%) were confirmed by CFR. The positive likelihood ratio of MRP for the presence of functional significant disease in patients with a lesion on CTCA was 4.49 (95% confidence interval [CI] 2.12-9.99). The negative likelihood ratio was 0.05 (95%CI 0.01-0.34). CONCLUSIONS: CTCA as first-line diagnostic modality excluded coronary artery disease in a high percentage of patients referred for diagnostic workup of suspected stable angina. MRP made a significant contribution to the detection of functional significant lesions in patients with a positive CTCA.

Diagnostic accuracy and clinical utility of noninvasive testing for coronary artery disease.

BACKGROUND: Computed tomography coronary angiography (CTCA) has become a popular noninvasive test for diagnosing coronary artery disease. OBJECTIVE: To compare the accuracy and clinical utility of stress testing and CTCA for identifying patients who require invasive coronary angiography (ICA). DESIGN: Observational study. SETTING: University medical center in Rotterdam, the Netherlands. PATIENTS: 517 patients referred by their treating physicians for evaluation of chest symptoms by using stress testing or ICA. INTERVENTION: Stress testing and CTCA in all patients. MEASUREMENTS: Diagnostic accuracy of stress testing and CTCA compared with ICA; pretest probabilities of disease by Duke clinical score; and clinical utility of noninvasive testing, defined as a pretest or posttest probability that suggests how to proceed with testing (no further testing if < or =5%, proceed with ICA if between 5% and 90%, and refer directly for ICA if > or =90%). RESULTS: Stress testing was not as accurate as CTCA; CTCA sensitivity approached 100%. In patients with a low (<20%) pretest probability of disease, negative stress test or CTCA results suggested no need for ICA. In patients with an intermediate (20% to 80%) pretest probability, a positive CTCA result suggested need to proceed with ICA (posttest probability, 93% [95% CI, 92% to 93%]) and a negative result suggested no need for further testing (posttest probability, 1% [CI, 1% to 1%]). Physicians could proceed directly with ICA in patients with a high (>80%) pretest probability (91% [CI, 90% to 92%]). LIMITATIONS: Referral and verification bias might have influenced findings. Stress testing provides functional information that may add value to that from anatomical (CTCA or ICA) imaging. CONCLUSION: Computed tomography coronary angiography seems most valuable in patients with intermediate pretest probability of disease, because the test can distinguish which of these patients need invasive angiography. These findings need to be confirmed before CTCA can be routinely recommended for these patients.

Diabetes: prognostic value of CT coronary angiography--comparison with a nondiabetic population.

PURPOSE: To evaluate the prognostic value of multidetector computed tomographic (CT) coronary angiography in a diabetic population known to have or suspected of having coronary artery disease (CAD) compared with that in nondiabetic individuals. MATERIALS AND METHODS: Institutional review board approval and patient informed consent were obtained. Three hundred thirteen patients with type 2 diabetes mellitus (DM) and 303 patients without DM underwent unenhanced 64-detector row CT, at which a calcium score was obtained, followed by CT angiography. Multidetector CT coronary angiograms were retrospectively classified as normal, showing nonobstructive CAD (50% luminal narrowing). During follow-up after CT angiography, major events (cardiac death, nonfatal myocardial infarction, and unstable angina requiring hospitalization) and total events (major events plus coronary revascularizations) were recorded for each patient. Cox proportional hazards analysis and Kaplan-Meier analysis were used to compare survival rates. RESULTS: In the group of 313 patients with DM, there were 213 men, and the mean age was 62 years +/- 11 (standard deviation). In the group of 303 patients without DM, there were 203 men, and the mean age was 63 years +/- 11. The mean number of diseased segments (5.6 vs 4.4, P = .001) and the rate of obstructive CAD (51% vs 37%, P < .001) were higher in patients with DM. Patients were followed up for a mean of 20 months +/- 5.4 (range, 6-44 months). At multivariate analysis, DM (P < .001) and evidence of obstructive CAD (P < .001) were independent predictors of outcome. Obstructive CAD remained a significant multivariate predictor for both patients with DM and patients without DM. In both patients with DM and patients without DM with absence of disease, the event rate was 0%. The event rate increased to 36% in patients without DM but with obstructive CAD and was highest (47%) in patients with DM and obstructive CAD. CONCLUSION: In both patients with DM and patients without DM, multidetector CT coronary angiography provides incremental prognostic information over baseline clinical variables, and the absence of atherosclerosis at CT coronary angiography is associated with an excellent prognosis. Multidetector CT coronary angiography might be a clinically useful tool for improving risk stratification in both patients with DM and patients without DM.

Incremental value of the CT coronary calcium score for the prediction of coronary artery disease.

OBJECTIVES: To validate published prediction models for the presence of obstructive coronary artery disease (CAD) in patients with new onset stable typical or atypical angina pectoris and to assess the incremental value of the CT coronary calcium score (CTCS). METHODS: We searched the literature for clinical prediction rules for the diagnosis of obstructive CAD, defined as ≥50% stenosis in at least one vessel on conventional coronary angiography. Significant variables were re-analysed in our dataset of 254 patients with logistic regression. CTCS was subsequently included in the models. The area under the receiver operating characteristic curve (AUC) was calculated to assess diagnostic performance. RESULTS: Re-analysing the variables used by Diamond & Forrester yielded an AUC of 0.798, which increased to 0.890 by adding CTCS. For Pryor, Morise 1994, Morise 1997 and Shaw the AUC increased from 0.838 to 0.901, 0.831 to 0.899, 0.840 to 0.898 and 0.833 to 0.899. CTCS significantly improved model performance in each model. CONCLUSIONS: Validation demonstrated good diagnostic performance across all models. CTCS improves the prediction of the presence of obstructive CAD, independent of clinical predictors, and should be considered in its diagnostic work-up.

Coronary calcium score and computed tomography coronary angiography in high-risk asymptomatic subjects: assessment of diagnostic accuracy and prevalence of non-obstructive coronary artery disease.

OBJECTIVES: The aim of the study was to compare the coronary artery calcium score (CACS) and computed tomography coronary angiography (CTCA) for the assessment of non-obstructive/obstructive coronary artery disease (CAD) in high-risk asymptomatic subjects. METHODS: Two hundred and thirteen consecutive asymptomatic subjects (113 male; mean age 53.6 +/- 12.4 years) with more than one risk factor and an inconclusive or unfeasible non-invasive stress test result underwent CACS and CTCA in an outpatient setting. All patients underwent conventional coronary angiography (CAG). Data from CACS (threshold for positive image: Agatston score 1/100/1,000) and CTCA were compared with CAG regarding the degree of CAD (non-obstructive/obstructive; or=50% lumen reduction). RESULTS: The mean calcium score was 151 +/- 403 and the prevalence of obstructive CAD was 17% (8% one-vessel and 10% two-vessel disease). Per-patient sensitivity, specificity, positive and negative predictive values of CACS were: 97%, 75%, 45%, and 100%, respectively (Agatston >or=1); 73%, 90%, 60%, and 94%, respectively (Agatston >or=100); 30%, 98%, 79%, and 87%, respectively (Agatston >or=1,000). Per-patient values for CTCA were 100%, 98%, 97%, and 100%, respectively (p < 0.05). CTCA detected 65% prevalence of all CAD (48% non-obstructive), while CACS detected 37% prevalence of all CAD (21% non-obstructive) (p < 0.05). CONCLUSION: CACS proved inadequate for the detection of obstructive and non-obstructive CAD compared with CTCA. CTCA has a high diagnostic accuracy for the detection of non-obstructive and obstructive CAD in high-risk asymptomatic patients with inconclusive or unfeasible stress test results.

Diagnostic accuracy of computed tomography coronary angiography in patients with a zero calcium score.

To evaluate the diagnostic accuracy of 64-slice CT coronary angiography (CT-CA) for the detection of significant coronary artery stenosis in patients with zero on the Agatston Calcium Score (CACS). We enrolled 279 consecutive patients (96 male, mean age 48 +/- 12 years) with suspected coronary artery disease. Patients were symptomatic (n = 208) or asymptomatic (n = 71), and underwent conventional coronary angiography (CAG). For CT-CA we administered an IV bolus of 100 ml of iodinated contrast material. CT-CA was compared to CAG using a threshold for significant stenosis of >or=50%. The prevalence of disease demonstrated at CAG was 15% (1.4% in asymptomatic). The population at CAG showed no or non-significant disease in 85% (238/279), single vessel disease in 9% (25/279), and multi-vessel disease in 6% (16/279). Sensitivity, specificity, and positive and negative predictive values of CT-CA vs. CAG on the patient level were 100%, 95%, 76%, and 100% in the overall population and 100%, 100%, 100%, and 100% in asymptomatic patients, respectively. CT-CA proves high diagnostic performance in patients with or without symptoms and with zero CACS. The prevalence of significant disease detected by CT-CA was not negligible in asymptomatic patients. The role of CT-CA in asymptomatic patients remains uncertain.

Diagnostic accuracy of 64-slice computed tomography coronary angiography for the detection of in-stent restenosis: a meta-analysis.

BACKGROUND: We sought to evaluate the diagnostic accuracy of 64-slice multi-detector row computed tomography (MDCT) compared with invasive coronary angiography for in-stent restenosis (ISR) detection. METHODS: MEDLINE, Cochrane library, and BioMed Central database searches were performed until April 2009 for original articles. Inclusion criteria were (1) 64-MDCT was used as a diagnostic test for ISR, with >50% diameter stenosis selected as the cut-off criterion for significant ISR, using invasive coronary angiography and quantitative coronary angiography as the standard of reference; (2) absolute numbers of true positive, false positive, true negative, and false negative results could be derived. Standard meta-analytic methods were applied. RESULTS: Nine studies with a total of 598 patients with 978 stents included were considered eligible. On average, 9% of stents were unassessable (range 0-42%). Accuracy tests with 95% confidence intervals (CIs) comparing 64-MDCT vs invasive coronary angiography showed that pooled sensitivity, specificity, positive and negative likelihood ratio (random effect model) values were: 86% (95% CI 80-91%), 93% (95% CI 91-95%), 12.32 (95% CI 7.26-20.92), 0.18 (95% CI 0.12-0.28) for binary ISR detection. The symmetric area under the curve value was 0.94, indicating good agreement between 64-MDCT and invasive coronary angiography. CONCLUSIONS: 64-MDCT has a good diagnostic accuracy for ISR detection with a particularly high negative predictive value. However, still a relatively large proportion of stents remains uninterpretable. Accordingly, only in selected patients, 64-MDCT may serve as a potential alternative noninvasive method to rule out ISR.

Minimally invasive autopsy: an alternative to conventional autopsy?

PURPOSE: To determine the diagnostic performance of minimally invasive autopsy (MIA) for detection of causes of death and to investigate the feasibility of MIA as an alternative to conventional autopsy (CA) in the clinical setting. MATERIALS AND METHODS: The institutional review board approved the MIA procedure and study, and informed consent was obtained for all deceased patients from relatives. Thirty deceased patients (19 men, 11 women; age range, 46-79 years), for whom family permission for CA on medical grounds had already been obtained, underwent additional evaluation with MIA prior to CA. MIA consisted of whole-body 16-section computed tomography (CT) and 1.5-T magnetic resonance (MR) imaging, followed by ultrasonography-guided 12-gauge needle biopsy of heart, both lungs, liver, both kidneys, and spleen. Percentage agreement between MIA and CA on cause of death was evaluated. Sensitivity and corresponding 95% confidence intervals (CIs) of MIA for detection of overall (major plus minor) findings, with CA as the reference standard, were calculated. Specificity was calculated for overall findings. Sensitivity analysis was performed to explore the effect of the clustered nature of the data. RESULTS: In 23 patients (77%), MIA and CA were in agreement on the cause of death. Sensitivity of MIA for detection of overall findings and detection of major findings was 93% (95% CI: 90%, 96%) and 94% (95% CI: 87%, 97%), respectively. Specificity was 99% (95% CI: 98%, 99%) for detection of overall findings. MIA failed to demonstrate acute myocardial infarction as the cause of death in four patients. Sensitivity analysis indicated a negligible correlation between observations within each patient. CT was superior to MR for detection of pneumothorax and calcifications. MR was superior to CT for detection of brain abnormalities and pulmonary embolus. With biopsy only, detection of disease in 55 organs was possible, which included 27 major findings. CONCLUSION: MIA is a feasible procedure with high diagnostic performance for detection of common causes of death such as pneumonia and sepsis; MIA failed to demonstrate cardiac diseases, such as acute myocardial infarction and endocarditis, as underlying cause of death. SUPPLEMENTAL MATERIAL: http://radiology.rsnajnls.org/cgi/content/full/250/3/897//DC1.

Preserved diagnostic performance of dual-source CT coronary angiography with reduced radiation exposure and cancer risk.

PURPOSE: To evaluate the effects of standard and optimal electrocardiographic (ECG) pulsing on diagnostic performance, radiation dose, and cancer risk in symptomatic patients in a "real-world" clinical setting. MATERIALS AND METHODS: The institutional review board approved the study, and all patients gave informed consent. Dual-source computed tomographic (CT) coronary angiography was performed in 436 symptomatic patients (301 men, 135 women; mean age, 61.6 years +/- 10.6 [standard deviation]; age range, 23-89 years) referred for conventional coronary angiography. Standard and optimal ECG pulsing was performed in 327 and 109 patients, respectively. The diagnostic performance of dual-source CT coronary angiography for detection of significant stenosis (>or=50 luminal diameter reduction), with quantitative coronary angiography as the reference standard, was reported as sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios. The mean effective radiation dose, additional fatal cancer risk, and age- and sex-specific cancer risks related to one CT coronary angiographic examination were determined from data averaged over the study population. RESULTS: Mean effective doses with standard and optimal ECG pulsing were 14.2 mSv +/- 3.2 and 10.7 mSv +/- 3.6, respectively. Optimal ECG pulsing resulted in a 43% overall reduction in mean effective radiation dose and cancer risk compared with a nonpulsing protocol (18.8 mSv +/- 3.5) and a 25% overall reduction in mean effective dose compared with the standard pulsing protocol. At patient-by-patient analysis, CT coronary angiography with standard ECG pulsing yielded sensitivity, specificity, and positive and negative predictive values of 100% (95% confidence interval [CI]: 99%, 100%), 85% (95% CI: 81%, 88%), 94% (95% CI: 91%, 96%), and 99% (95% CI: 98%, 100%), respectively, for detection of significant stenosis. Optimal ECG pulsing yielded similar results: Sensitivity, specificity, and positive and negative predictive values were 100% (95% CI: 100%, 100%), 88% (95% CI: 82%, 94%), 97% (95% CI: 93%, 100%), and 100%, respectively. CONCLUSION: Compared with a nonpulsing protocol, optimal ECG pulsing resulted in significant (P < .001) reductions in patient radiation dose and cancer risk (up to 55% reduction in patients with high heart rates) while preserving the diagnostic performance of dual-source CT coronary angiography.

Learning curve for coronary CT angiography: what constitutes sufficient training?

PURPOSE: To prospectively evaluate the effect of experience with coronary computed tomographic (CT) angiography on the capability to detect coronary stenoses of 50% or more. MATERIALS AND METHODS: The institutional review board approved the study protocol. All patients gave consent to undergo CT angiography before conventional coronary angiography after being informed of the additional radiation dose. They also consented to the use of their data for future research. Three radiologists and one cardiologist inexperienced with coronary CT angiography attended this institution's cardiac CT unit for a 1-year fellowship. Fellows were involved in the acquisition and reading of 12-15 coronary CT angiograms per week (about 600 per year). To assess the progression in diagnostic performance, fellows (readers) independently read 50 CT angiographic test cases in patients who also underwent conventional coronary angiography. Cases were repeatedly assigned in random order at baseline and at 4, 8, 26, and 52 weeks. The same cases were examined by two experts in consensus. Sensitivity, specificity, and diagnostic odds ratios (DORs) were calculated and compared with conventional coronary angiography as the reference standard. RESULTS: Respective reader ranges for sensitivity, specificity, and DOR were 33%-72%, 70%-94%, and 3.8-8.1 at baseline; 43%-80%, 71%-88%, and 8.8-15.2 after 6 months; and 66%-75%, 87%-92%, and 14.7-25.8 after 1 year. For expert physicians, respective results were 95%, 93%, and 255.9. Between baseline and 6 months, readers 1-3 showed nonsignificantly improved sensitivities, while specificities remained similar. Reader 4 showed significantly improved specificity, while sensitivity remained similar; all readers nonsignificantly improved DORs. Between baseline and 1 year: readers 1 and 2 significantly improved sensitivity but not specificity; reader 4 significantly improved specificity but not sensitivity; readers 1, 2, and 4 improved DOR significantly; reader 3 nonsignificantly improved sensitivity, specificity, and DOR. CONCLUSION: Increasing experience with coronary CT angiography improved the diagnostic performance of inexperienced physicians. However, acquiring expertise in coronary CT angiography was slow and may take more than 1 year.

CT coronary angiography in patients suspected of having coronary artery disease: decision making from various perspectives in the face of uncertainty.

PURPOSE: To determine the cost-effectiveness of computed tomographic (CT) coronary angiography as a triage test, performed prior to conventional coronary angiography, by using a Markov model. MATERIALS AND METHODS: A Markov model was used to analyze the cost-effectiveness of CT coronary angiography performed as a triage test prior to conventional coronary angiography from the perspective of the patient, physician, hospital, health care system, and society by using recommendations from the United Kingdom, the United States, and the Netherlands for cost-effectiveness analyses. For CT coronary angiography, a range of sensitivities (79%-100%) and specificities (63%-94%) were used to help diagnose significant coronary artery disease (CAD). Optimization criteria (ie, outcomes considered) were: revised posttest probability of CAD, life-years, quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). Extensive sensitivity analysis was performed. RESULTS: For a prior probability of CAD of less than 40%, the probability of CAD after CT coronary angiography with negative results was less than 1%. The Markov model calculations from the patient/physician perspective suggest that CT coronary angiography maximizes life-years respectively in 60-year-old men and women at a prior probability of less than 38% and 24% and maximizes QALYs at a prior probability of less than 17% and 11%. From the hospital/health care perspective, CT coronary angiography helps reduce health care and direct nonhealth care-related costs (according to UK/U.S. recommendations), regardless of prior probability, and lowers all costs, including production losses (Netherlands recommendations) at a prior probability of less than 87%-92%. Analysis performed from a societal perspective by using a willingness-to-pay threshold level of euro 80,000/QALY suggests that CT coronary angiography is cost-effective when the prior probability is lower than 44% and 37% in men and women, respectively. Sensitivity analyses showed that results changed across the reported range of sensitivity of CT coronary angiography. CONCLUSION: The optimal diagnostic work-up depends on the optimization criterion, prior probability of CAD, and the diagnostic performance of CT coronary angiography.

Impact of heart rate frequency and variability on radiation exposure, image quality, and diagnostic performance in dual-source spiral CT coronary angiography.

PURPOSE: To investigate the effect of heart rate frequency (HRF) and heart rate variability (HRV) on radiation exposure, image quality, and diagnostic performance to help detect significant stenosis (> or =50% lumen diameter reduction) by using adaptive electrocardiographic (ECG) pulsing at dual-source (DS) spiral computed tomographic (CT) coronary angiography. MATERIALS AND METHODS: Institutional review committee approval and informed consent were obtained. No prescan beta-blockers were applied. Unenhanced CT and CT coronary angiography with adaptive ECG pulsing were performed in 927 consecutive patients (600 men, 327 women; mean age, 60.3 years +/- 11.0 [standard deviation]) divided in three HRF groups: low, intermediate, and high (< or =65, 66-79, and > or =80 beats/min, respectively), and four HRV groups given mean interbeat difference (IBD) during CT coronary angiography: normal, minor, moderate, and severe (IBDs of 0-1, 2-3, 4-10, and >10, respectively). Radiation exposure and image quality were also evaluated. In 444 of these, diagnostic performance was presented as sensitivity, specificity, positive predictive values (PPVs), and negative predictive values and likelihood ratios with corresponding 95% confidence intervals by using quantitative coronary angiography as the reference standard. RESULTS: CT coronary angiography yielded good image quality in 98% of patients and no significant differences in image quality were found among HRF and HRV groups. Radiation exposure was significantly higher in patients with low versus high HRF and in patients with severe versus normal HRV. No significant differences among HRF and HRV groups in image quality and diagnostic performance were found. A nonsignificant trend was found toward a lower specificity and PPV in patients with a high HRF or severe HRV when compared with low HRF or normal HRV in patients with a low calcium score (Agatston score <100). CONCLUSION: DS spiral CT coronary angiography performed with adaptive ECG pulsing results in preserved diagnostic image quality and performance independent of HRF or HRV at the cost of limited dose reduction in arrhythmic patients.