Analysis of coronary computed tomography angiography-derived pericoronary fat attenuation index characteristics in the diagnostic assessment of patients with Takayasu arteritis.

Background: The clinical value of pericoronary adipose tissue in assessing Takayasu arteritis (TAK) with coronary artery involvement (CAI) is yet to be determined. The purpose of this study was to investigate the characteristics of pericoronary fat attenuation index (FAI) derived from coronary computed tomography angiography (CTA) in patients with TAK. Methods: This is a retrospective study involving enrollment of 111 consecutive patients (mean age, 33.92±12.48 years) who were diagnosed as TAK, of which 52 patients had coronary artery involvement (TAK-CAI) and 59 patients without coronary artery involvement (TAK-nonCAI). Based on the extent of coronary artery lesion, the TAK-CAI group was further classified into localized group (n=25) and diffused group (n=27). Furthermore, patients with TAK were divided into active group (n=33) and inactive group (n=78). Meanwhile, 51 gender-matched individuals with normal appearance in coronary CTA examination were enrolled as the control group. The pericoronary FAI was quantitatively evaluated on each coronary CTA examination groups. The diagnostic value of pericoronary FAI was determined using the area under the curve (AUC) of the receiver operating characteristic. Results: A higher pericoronary FAI was found in TAK-nonCAI group than control group with normal coronary arteries (P<0.001). Multivariate analysis showed that the FAI is an independent risk factor for coronary involvement in TAK patients [odds ratio (OR): 1.23, 95% confidence interval (CI): 1.13-1.35, P<0.001]. With the best cut-off value of -86.50, the pericoronary FAI identified coronary involvement with 67.8% sensitivity and 74.5% specificity (AUC: 0.794, 95% CI: 0.713-0.875, P<0.001). Multivariate analysis showed that the pericoronary FAI is an independent risk factor for determination of active TAK patients (OR: 1.57, 95% CI: 1.25-1.97, P<0.001). With the best cut-off value of -79.50, the pericoronary FAI identified active inflammation with 93.9% sensitivity and 74.4% specificity (AUC: 0.911, 95% CI: 0.860-0.962, P<0.001). Conclusions: Coronary CTA-derived FAI is significantly increased in patients with TAK and can be used as a reliable biomarker to distinguish TAK patients from those with normal coronary arteries, and determine the extent of TAK inflammation.

Extending Cardiac Functional Assessment with Respiratory-Resolved 3D Cine MRI.

This study aimed to develop a cardiorespiratory-resolved 3D magnetic resonance imaging (5D MRI: x-y-z-cardiac-respiratory) approach based on 3D motion tracking for investigating the influence of respiration on cardiac ventricular function. A highly-accelerated 2.5-minute sparse MR protocol was developed for a continuous acquisition of cardiac images through multiple cardiac and respiratory cycles. The heart displacement along respiration was extracted using a 3D image deformation algorithm, and this information was used to cluster the acquired data into multiple respiratory phases. The proposed approach was tested in 15 healthy volunteers (7 females). Cardiac function parameters, including the end-systolic volume (ESV), end-diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF), were measured for the left and right ventricle in both end-expiration and end-inspiration. Although with the proposed 5D cardiac MRI, there were no significant differences (p > 0.05, t-test) between end-expiration and end-inspiration measurements of the cardiac function in volunteers, incremental respiratory motion parameters that were derived from 3D motion tracking, such as the depth, expiration and inspiration distribution, correlated (p < 0.05, correlation coefficient, Mann-Whitney) with those volume-based parameters of cardiac function and varied between genders. The obtained initial results suggested that this new approach allows evaluation of cardiac function during specific respiratory phases. Thus, it can enable investigation of effects related to respiratory variability and better assessment of cardiac function for studying respiratory and/or cardiac dysfunction.

Image Quality and Stenosis Assessment of Non-Contrast-Enhanced 3-T Magnetic Resonance Angiography in Patients with Peripheral Artery Disease Compared with Contrast-Enhanced Magnetic Resonance Angiography and Digital Subtraction Angiography.

PURPOSE: To evaluate the diagnostic performance of flow-sensitive dephasing (FSD)-prepared steady-state free precession (SSFP) magnetic resonance angiography (MRA) at 3 T for imaging infragenual arteries relative to contrast-enhanced MRA (CE-MRA) and digital subtraction angiography (DSA). MATERIALS AND METHODS: A series of 16 consecutive patients with peripheral arterial disease (PAD) underwent a combined peripheral MRA protocol consisting of FSD-MRA for the calves and large field-of-view CE-MRA. DSA was performed on all patients within 1 week of the MR angiographies. Image quality and degree of stenosis was assessed by two readers with rich experience. Inter-observer agreement was determined using kappa statistics. Receiver operating characteristic (ROC) curve analysis determined the diagnostic value of FSD-MRA, CE-MRA, and CE-MRA combined with FSD-MRA (CE+FSD MRA) in predicting vascular stenosis. RESULTS: At the calf station, no significantly difference of subjective image quality scores was found between FSD-MRA and CE-MRA. Inter-reader agreement was excellent for both FSD-MRA and CE-MRA. Both of FSD-MRA and CE-MRA carry a stenosis overestimation risk relative to DSA standard. With DSA as the reference standard, ROC curve analysis showed that the area under the curve was largest for CE+FSD MRA. The greatest sensitivity and specificity were obtained when a cut-off stenosis score of 2 was used. CONCLUSION: In patients with severe PAD,3 T FSD-MRA provides good-quality diagnostic images without a contrast agent and is a good supplement for CE-MRA. CE+FSD MRA can improve the accuracy of vascular stenosis diagnosis.

Left Ventricular Diastolic Dysfunction Assessment with Dual-Source CT.

PURPOSE: To assess the impact of left ventricular (LV) diastolic dysfunction on left atrial (LA) phasic volume and function using dual-source CT (DSCT) and to find a viable alternative prognostic parameter of CT for LV diastolic dysfunction through quantitative evaluation of LA phasic volume and function in patients with LV diastolic dysfunction. MATERIALS AND METHODS: Seventy-seven patients were examined using DSCT and Doppler echocardiography on the same day. Reservoir, conduit, and contractile function of LA were evaluated by measuring LA volume (LAV) during different cardiac phases and all parameters were normalized to body surface area (BSA). Patients were divided into four groups (normal, impaired relaxation, pseudonormal, and restrictive LV diastolic filling) according to echocardiographic findings. The LA phasic volume and function in different stages of LV diastolic function was compared using one-way ANOVA analysis. The correlations between indexed volume of LA (LAVi) and diastolic function in different stages of LV were evaluated using Spearman correlation analysis. RESULTS: LA ejection fraction (LAEF), LA contraction, reservoir, and conduit function in patients in impaired relaxation group were not different from those in the normal group, but they were lower in patients in the pseudonormal and restrictive LV diastolic dysfunction groups (P < 0.05). For LA conduit function, there were no significant differences between the patients in the pseudonormal group and restrictive filling group (P = 0.195). There was a strong correlation between the indexed maximal left atrial volume (LAVmax, r = 0.85, P < 0.001), minimal left atrial volume (LAVmin, r = 0.91, P < 0.001), left atrial volume at the onset of P wave (LAVp, r = 0.84, P < 0.001), and different stages of LV diastolic function. The LAVi increased as the severity of LV diastolic dysfunction increased. CONCLUSIONS: LA remodeling takes place in patients with LV diastolic dysfunction. At the same time, LA phasic volume and function parameters evaluated by DSCT indicated the severity of the LV diastolic dysfunction. Quantitative analysis of LA phasic volume and function parameters using DSCT could be a viable alternative prognostic parameter of LV diastolic function.