Search

Background: Rapid plaque progression (RPP) is associated with a higher risk of acute coronary syndromes compared with gradual plaque progression. We aimed to develop and validate a coronary computed tomography angiography (CCTA)-based radiomics signature (RS) of plaques for predicting RPP., Methods: A total of 214 patients who underwent serial CCTA examinations from 2 tertiary hospitals (development group, 137 patients with 164 lesions; validation group, 77 patients with 101 lesions) were retrospectively enrolled. Conventional CCTA-defined morphological parameters (eg, high-risk plaque characteristics and plaque burden) and radiomics features of plaques were analyzed. RPP was defined as an annual progression of plaque burden ≥1.0% on lesion-level at follow-up CCTA. RS was built to predict RPP using XGBoost method., Results: RS significantly outperformed morphological parameters for predicting RPP in both the development group (area under the receiver operating characteristic curve, 0.82 versus 0.74; P =0.04) and validation group (area under the receiver operating characteristic curve, 0.81 versus 0.69; P =0.04). Multivariable analysis identified RS (odds ratio, 2.35 [95% CI, 1.32-4.46]; P =0.005) as an independent predictor of subsequent RPP in the validation group after adjustment of morphological confounders. Unlike unchanged RS in the non-RPP group, RS increased significantly in the RPP group at follow-up in the whole dataset ( P <0.001)., Conclusions: The proposed CCTA-based RS had a better discriminative value to identify plaques at risk of rapid progression compared with conventional morphological plaque parameters. These data suggest the promising utility of radiomics for predicting RPP in a low-risk group on CCTA., Competing Interests: Disclosures None.

Objectives: To evaluate the feasibility of non-electrocardiogram (ECG)-triggered 70-kVp high-pitch aortic computed tomography angiography (CTA) with iterative reconstruction (IR) and reduced contrast agent using second-generation dual-source CT (DSCT)., Methods: Seventy-seven patients were examined: group A (n = 21), 70-kVp high-pitch (3.2) CTA, 60 mL contrast agent and IR on second-generation DSCT; group B (n = 29), standard-pitch (1.2) CTA, automatic tube voltage selection, filtered back projection and 80 mL contrast agent on second-generation DSCT; group C (n = 27), 120-kVp standard-pitch (1.2) CTA, filtered back projection, and 80 mL contrast agent on first-generation DSCT. Computed tomography values, noise, signal-to-noise ratio, contrast-to-noise ratio, and subjective image quality were compared., Results: Computed tomography values and noise of all aortic segments in group A were increased compared with groups B and C (P < 0.05). Group B showed the highest signal-to-noise ratio and contrast-to-noise ratio for all aortic segments (P < 0.05), whereas no significant differences were found between groups A and C (P > 0.05). Mean effective dose was 0.88 ± 0.08 mSv for group A, reduced by 93% compared to group C and by 90% compared to group B., Conclusions: Non-ECG-triggered 70-kVp high-pitch aortic CTA with IR provides equivalent diagnostic image quality with 90% reduction of radiation dose and 25% reduction of contrast volume compared with standard 120-kVp CTA.

To investigate the effect of apolipoprotein E (APOE) gene polymorphism on the resting-state brain function, structure, and blood flow in healthy adults younger than 35 years, using multimodality magnetic resonance (MR) imaging.Seventy-six healthy adults (34 men, 23.7 ± 2.8 y; 31 APOE ε4/ε3 carriers, 31 ε3/ε3 carriers, and 14 ε2/ε3 carriers) were included. For resting-state functional MRI data, default mode network (DMN) and amplitude of low-frequency fluctuation maps were extracted and analyzed. Voxel-based morphometry, diffusion tensor imaging from structural imaging, and cerebral blood flow based on arterial spin labeling MR imaging were also analyzed. Correlation analysis was performed between the above mentioned brain parameters and neuropsychological tests.There were no differences in neuropsychological performances, amplitude of low-frequency fluctuation, gray/white matter volumes, fractional anisotropy, mean diffusivity, or whole brain cerebral blood flow among the 3 groups. As for DMN, the ε4/ε3 group showed increased functional connectivities (FCs) in the left medial prefrontal cortex and bilateral posterior cingulate cortices/precuneus compared with the ε3/ε3 group, and increased FCs in the left medial prefrontal cortex and right temporal lobe compared with the ε2/ε3 group (P < 0.05, Alphasim corrected). No differences of DMN FCs were found between the ε2/ε3 and ε3/ε3 groups. FCs in the right temporal lobe positively correlated with the performances of vocabulary learning, delayed recall, and graph recall in all participants (P < 0.05).APOE ε4 carriers exhibited significantly increased DMN FCs when compared with ε3 and ε2 carriers. The ε4 affects DMN FCs before brain structure and blood flow in cognitively intact young patients, suggesting DMN FC may serve as a potential biomarker for the detection of early manifestations of genetic effect., Competing Interests: UJS is a consultant for and/or receives research support from Bayer, Bracco, GE Healthcare, Medrad, and Siemens Healthcare. All other authors had no conflict of interest to declare.

Purpose: To evaluate the diagnostic accuracy of dual-energy computed tomographic angiography (DE-CTA) in the detection of intracranial aneurysms and to determine whether DE-CTA provides adequate information to guide treatment choice., Materials and Methods: Eighty patients (31 men and 49 women; mean [SD] ages of 52 [9] years) with spontaneous subarachnoid hemorrhage underwent DE-CTA. The performance of DE-CTA was compared with conventional CTA created from average weighted images and digital subtraction angiography (DSA). Sensitivity and specificity for aneurysm detection were determined on a per-patient and per-aneurysm basis. The treatment choice was assessed on the basis of aneurysm neck size and/or the dome/neck ratio., Results: With DSA as reference standard (n = 61; 47 aneurysms in 41 patients), DE-CTA correctly detected 45 aneurysms in 41 patients corresponding to sensitivity and specificity of 100% and 95.0% on a per-patient basis versus 95.7% and 95.0% on a per-aneurysm basis, whereas conventional CTA correctly detected 43 aneurysms in 39 patients corresponding to sensitivity and specificity of 95.1% and 95.0% on a per-patient basis versus 91.5% and 95.0% on a per-aneurysm basis. No statistical difference between DE-CTA and conventional CTA was found for the diagnostic evaluation of intracranial aneurysms. Surgery was performed to treat 38 aneurysms, coiling in 26 aneurysms, stent in one patient, and follow-up in the remaining 5 aneurysms. Dual-energy CTA correctly predicted treatment choice in 44 aneurysms, with 15 aneurysms coiled and 29 aneurysms clipped., Conclusions: Compared with DSA, DE-CTA had a comparable diagnostic accuracy for the detection of intracranial aneurysms, visualization of the morphology of aneurysms at the skull base, and prediction of aneurysm treatment choice in most patients with spontaneous subarachnoid hemorrhage based on this study.

Purpose: To evaluate the feasibility and value of dual-energy computed tomography myocardial iodine maps in the diagnosis of acute myocardial infarction., Materials and Methods: In 6 dogs, arterial-phase myocardial dual-energy computed tomography imaging were performed 1 day prior to and 3 hours after the surgical ligation of the left anterior descending artery to generate 100 kVp, 140 kVp, average weighted images, and dual energy myocardial iodine maps. For each of the 17 segments of the left ventricle (LV, 102 total segments), the presence or absence myocardial infarction was determined by histopathology and correlated to blinded reader determination of infarcted and noninfarcted myocardium at computed tomography (CT). Statistical analysis for diagnostic accuracy of aforementioned techniques and inter-reader agreement was performed., Results: The LV myocardial contrast enhancement at the average weighted images and iodine maps were uniform in all 6 dogs before surgery. Following anterior descending artery ligation, histopathology showed 40 infarcted left ventricular segments and 62 noninfarcted segments. For the postligation CT scans, 100 kVp, 140 kVp, average weighted images, and myocardial iodine maps showed 33, 28, 33, 34 infarcted segments and 53, 56, 56, 52 noninfarcted segments for both readers; corresponding to per-segment sensitivities of 83%, 70%, 80%, 92% and specificities of 85%, 90%, 92%, 80% for detecting myocardial infarction. No statistical difference was found for diagnostic accuracy of 100 kV, 140 kV, weighted average images, and iodine maps to detect myocardial infarct segments (all P > 0.05 for both readers). Good inter-reader agreement was seen for myocardial infarct detection using iodine maps (kappa = 0.80)., Conclusions: Myocardial single- and dual-energy CT imaging shows high per-segment sensitivity and moderate specificity for detecting acute myocardial infarction in a canine model with histopathology as the standard of reference.

Purpose: The purpose of this study was to assess the clinical value of dual-source computed tomography (DSCT) in the detection and dynamic evaluation of the anomalous origin of the right coronary artery originating from the left coronary sinus of Valsalva (ARCAOLS) with an interarterial course., Materials and Methods: Thirteen patients with ARCAOLS with an interarterial course and 11 controls with normal origin of the right coronary artery (RCA) were included into this study from December 2006 to April 2008. The origin and course of the RCA were determined on maximum intensity projection, volume rendering, and virtual endoscopy images. The diameter of the proximal segment of the RCA was measured dynamically in all phases of the cardiac cycle; the systolic stenostic rate of the proximal RCA was computed. The angle between the aorta and the proximal segment of RCA was also measured., Results: The average heart rate was 71.92 and 70.76 beats/min for patients and controls, respectively. The systolic image quality score of proximal RCA was 4, whereas the diastolic image quality score of proximal RCA was 3.82. Reformatted images could clearly display the ARCAOLS with a smaller orifice than that of the left coronary artery, coursing in an acute angle between the ascending aorta and the pulmonary artery trunk (P = 0.000). In addition to 2 cases without complete computed tomography data, 11 other cases had complete data being used for dynamic assessment. The average systolic diameter of the proximal RCA in mean (SD) was 1.76 mm (0.54 mm), whereas the diastolic diameter was 2.13 mm (0.62 mm) (P = 0.004) for patients with a stenostic rate of the proximal RCA of 16.83 (13.47). The average systolic diameter of the proximal RCA was 3.49 mm (0.61 mm), whereas the diastolic diameter was 3.78 mm (0.63 mm) (P = 0.000) for 11 controls., Conclusions: Compared with normal controls, the patients with ARCAOLS had a smaller orifice, an acute angle between the aorta and the RCA, and a narrower diameter of the proximal RCA. Dual-source computed tomography can clearly show the anomalous origin, orifice, angle, and course of RCA and dynamically evaluate the diameter changes of proximal RCA during the cardiac cycle, providing useful clues to clarify the mechanism of myocardial ischemia.