Quantitative coronary plaque analysis predicts high-risk plaque morphology on coronary computed tomography angiography: results from the ROMICAT II trial

Semi-automated software can provide quantitative assessment of atherosclerotic plaques on coronary CT angiography (CTA). The relationship between established qualitative high-risk plaque features and quantitative plaque measurements has not been studied. We analyzed the association between quantitative plaque measurements and qualitative high-risk plaque features on coronary CTA. We included 260 patients with plaque who underwent coronary CTA in the Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT) II trial. Quantitative plaque assessment and qualitative plaque characterization were performed on a per coronary segment basis. Quantitative coronary plaque measurements included plaque volume, plaque burden, remodeling index, and diameter stenosis. In qualitative analysis, high-risk plaque was present if positive remodeling, low CT attenuation plaque, napkin-ring sign or spotty calcium were detected. Univariable and multivariable logistic regression analyses were performed to assess the association between quantitative and qualitative high-risk plaque assessment. Among 888 segments with coronary plaque, high-risk plaque was present in 391 (44.0%) segments by qualitative analysis. In quantitative analysis, segments with high-risk plaque had higher total plaque volume, low CT attenuation plaque volume, plaque burden and remodeling index. Quantitatively assessed low CT attenuation plaque volume (odds ratio 1.12 per 1 mm3, 95% CI 1.04-1.21), positive remodeling (odds ratio 1.25 per 0.1, 95% CI 1.10-1.41) and plaque burden (odds ratio 1.53 per 0.1, 95% CI 1.08-2.16) were associated with high-risk plaque. Quantitative coronary plaque characteristics (low CT attenuation plaque volume, positive remodeling and plaque burden) measured by semi-automated software correlated with qualitative assessment of high-risk plaque features

The effect of iterative image reconstruction algorithms on the feasibility of automated plaque assessment in coronary CT angiography.

To evaluate the effect of adaptive statistical (ASIR) and model based (MBIR) iterative reconstruction algorithms on the feasibility of automated plaque assessment in coronary computed tomography angiography (CCTA) compared to filtered back projection reconstruction (FBPR) algorithm. Three ex vivo human donor hearts were imaged by CCTA and reconstructed with FBPR, ASIR and MBIR. Commercial plaque assessment software was applied for the automated delineation of the outer and inner vessel-wall boundaries. Manually corrections were performed where necessary and the percentages were compared between the reconstruction algorithms. In total 2,295 CCTA cross-sections with 0.5 mm increments were assessed (765 co-registered FBPR/ASIR/MBIR triplets). Any boundary corrections were performed in 31.0% of all cross-sections (N = 712). The percentage of corrected crosssections was lower for MBIR (24.1%) as compared to ASIR (32.4%, p = 0.0003) and FBPR (36.6%, p <0.0001), and marginal between ASIR/FBPR (p = 0.09). The benefit of MBIR over FBPR was associated with the presence of moderate and severe calcification (OR 2.9 and 5.7, p <0.0001; respectively). Using MBIR significantly reduced the need for vessel-wall boundary corrections compared to other reconstruction algorithms, particular at the site of calcifications. Thus, MBIR may improve the feasibility of automated plaque assessment in CCTA and potentially its clinical applicability

Catecholamine Surge during Image-Guided Ablation of Adrenal Gland Metastases: Predictors, Consequences, and Recommendations for Management.

PURPOSE: To identify retrospectively predictors of catecholamine surge during image-guided ablation of metastases to the adrenal gland. MATERIALS AND METHODS: Between 2001 and 2014, 57 patients (39 men, 18 women; mean age, 65 y ± 10; age range, 41-81 y) at two academic medical centers underwent ablation of 64 metastatic adrenal tumors from renal cell carcinoma (n = 27), lung cancer (n = 23), melanoma (n = 4), colorectal cancer (n = 3), and other tumors (n = 7). Tumors measured 0.7-11.3 cm (mean, 4 cm ± 2.5). Modalities included cryoablation (n = 38), radiofrequency (RF) ablation (n = 20), RF ablation with injection of dehydrated ethanol (n = 10), and microwave ablation (n = 4). Fisher exact test, univariate, and multivariate logistical regression analysis was used to evaluate factors predicting hypertensive crisis (HC). RESULTS: HC occurred in 31 sessions (43%). Ventricular tachycardia (n = 1), atrial fibrillation (n = 2), and troponin leak (n = 4) developed during HC episodes. HC was significantly associated with maximum tumor diameter ≤ 4.5 cm (odds ratio [OR], 26.36; 95% confidence interval [CI], 5.26-131.99; P \u3c .0001) and visualization of normal adrenal tissue on CT or MR imaging before the procedure (OR, 8.38; 95% CI, 2.67-25.33; P \u3c .0001). No HC occurred during ablation of metastases in previously irradiated or ablated adrenal glands. CONCLUSIONS: Patients at high risk of catecholamine surge during ablation of non-hormonally active adrenal metastases can be identified by the presence of normal adrenal tissue and tumor diameter ≤ 4.5 cm on pre-procedure CT or MR imaging