Baseline vessel wall magnetic resonance imaging characteristics associated with in-stent restenosis for intracranial atherosclerotic stenosis.

BACKGROUND: Imaging factors, specifically baseline plaque features on high-resolution magnetic resonance vessel wall imaging (HR-VWI) that could be associated with in-stent restenosis (ISR), are still unknown. We aimed to investigate the presenting clinical and plaque features on HR-VWI associated with ISR. METHODS: Sixty-four patients with intracranial stent placement for intracranial atherosclerotic stenosis who had pre- and post-contrast T1-weighted HR-VWI on 3.0T prior to stenting were included in this analysis. Student's t-test, Mann-Whitney U test, χ2 test, or the Cochran-Mantel-Haenszel (CMH) test were used to compare clinical and baseline HR-VWI characteristics of the patients between the ISR and non-ISR groups. Univariable and multivariable logistic analysis were used to test the clinical and imaging factors associated with ISR. RESULTS: Among the 64 patients, 9 patients (14.06%) developed ISR during the 2-year follow-up period. Plaque burden (median 0.89 vs 0.92, P=0.04), minimum lumen area (0.009 cm2 vs 0.006 cm2, P=0.04), plaque eccentricity (55.6% vs 89.1%, P＜0.01), enhancement ratio (1.36 vs 0.84, P＜0.01), and enhancement involvement (type 2 represents ≥50% cross-sectional wall involvement; 100% vs 63.6%, P=0.03) all significantly differed between patients with and without ISR. Multivariable analysis revealed that lower frequency of plaque eccentricity (OR 0.18, 95% CI 0.04 to 0.96, P=0.04) and higher enhancement ratio (OR 3.57, 95% CI 1.02 to 12.48, P=0.04) were independently associated with ISR. CONCLUSIONS: Preliminary findings showed that ISR was independently associated with plaque concentricity and higher enhancement ratios on pre-stenting HR-VWI for patients with symptomatic intracranial atherosclerotic stenosis.

Fat poor angiomyolipoma differentiation from renal cell carcinoma at 320-slice dynamic volume CT perfusion.

PURPOSE: To compare various CT perfusion features of fat poor angiomyolipoma (AML) with those of size-matched renal cell carcinoma (RCC). METHODS: One hundred and seventy-four patients [16 with fat poor AML (mean diameter, 3.1 cm; range, 1.5-5.5 cm) and 158 with RCC (mean diameter, 3.2 cm; range, 2.4-5.4 cm)] who had undergone 320-slice dynamic volume CT perfusion were evaluated. Equivalent blood volume (BV Equiv), permeability surface-area product (PS), and blood flow (BF) of tumor were measured and analyzed. Fat poor AML was compared with each subtype of RCC (132 clear cell, 9 papillary, and 17 chromophobe). Receiver operating characteristic (ROC) curve analysis was performed for the comparison of fat poor AML and RCC. ROC curve analysis was not performed for the papillary RCC subtype because of the small number of masses of this subtype. RESULTS: BV Equiv and BF were significantly lower in fat poor AML than in clear cell RCC (P < 0.05 for both). Fat poor AML had higher BV Equiv, PS, and BF than papillary RCC (P < 0.05 for all). PS and BF in fat poor AML significantly exceeded those in chromophobe RCC (P < 0.05 for both). For differentiating fat poor AML from clear cell RCC, area under the ROC curve (AUC) of BV Equiv and BF were 0.82 and 0.69. Using the optimal threshold value, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 0.82, 0.81, 0.35, 0.97 for BV Equiv and 0.71, 0.75, 0.24, 0.96 for BF, respectively. For differentiating fat poor AML from chromophobe RCC, AUC of PS and BF were 0.77 and 0.79, respectively. The optimal sensitivity, specificity, PPV, and NPV were 0.77, 0.75, 0.75, 0.76 for PS and 0.71, 0.81, 0.72, 0.80 for BF, respectively. CONCLUSIONS: Fat poor AML and subtypes of RCCs demonstrate different perfusion features at 320-slice dynamic volume CT, allowing their differentiations with BV Equiv, PS, and BF being valuable perfusion parameters.

Comparative study of 4D CTA and DSA for vascular assessment in moyamoya disease.

PURPOSE: To evaluate the vascular stenosis and collateral circulation in moyamoya disease using 4D CTA. METHODS: Two neuroradiologists evaluated 4D CTA and DSA for 101 moyamoya patients. The performance of 4D CTA relative to DSA was determined using consistency checks (kappa values, 95% CI) and correlation analysis. RESULTS: The kappa values were 0.714 (modified Suzuki score), 0.846 (Houkin score), 0.594 (basicranial moyamoya vessels), 0.435 (posterior circulation collaterals) and 0.591 (ECA collaterals). The correlation coefficients were 0.843, 0.872, 0.792, 0.635 and 0.797. CONCLUSIONS: 4D CTA showed strong consistency and correlation with DSA in the vascular stenosis score, but was insufficient in collateral circulation evaluation.

Differentiation of low- and high-grade clear cell renal cell carcinoma: Tumor size versus CT perfusion parameters.

PURPOSE: To compare the utility of tumor size and CT perfusion parameters for differentiation of low- and high-grade clear cell renal cell carcinoma (RCC). MATERIALS AND METHODS: Tumor size, Equivalent blood volume (Equiv BV), permeability surface-area product (PS), blood flow (BF), and Fuhrman pathological grading of clear cell RCC were retrospectively analyzed. RESULTS: High-grade clear cell RCC had significantly higher tumor size and lower PS than low grade. Tumor size positively correlated with Fuhrman grade, but PS negatively did. CONCLUSIONS: Tumor size and PS were significantly independent indexes for differentiating high-grade from low-grade clear cell RCC.

Correlation between CT perfusion parameters and Fuhrman grade in pTlb renal cell carcinoma.

PURPOSE: To evaluate the correlation of CT perfusion parameters with the Fuhrman grade in pT1b (4-7 cm) renal cell carcinoma (RCC). METHODS: CT perfusion imaging and Fuhrman pathological grading of pT1b RCC were performed in 48 patients (10 grade 1, 27 grade 2, 9 grade 3, and 2 grade 4). Equivalent blood volume (BV Equiv), permeability surface area product (PS), and blood flow (BF) of tumors were measured. Grade 1 and 2 were defined as low-grade group (n = 37), meanwhile high-grade group (n = 11) included grade 3 and 4. Comparisons of CT perfusion parameters and tumor size of the two different groups were performed. Correlations between CT perfusion parameters, Fuhrman grade (grade 1, 2, 3, and 4), and tumor size were assessed. RESULTS: PS was significantly lower in high grade than in low-grade pT1b RCC (P = 0.004). However, no significant differences were found in BV Equiv and BF between the two groups (P > 0.05 for both). The optimal threshold value, sensitivity, specificity, and the area under the ROC curve for distinguishing the two groups using PS were 68.8 mL/100 g/min, 0.7, 0.8, and 0.8, respectively. Negative significant correlation was observed between PS and Fuhrman grade (r = -0.338, P = 0.019). CONCLUSIONS: The PS of pT1b RCC had negative significant correlation with Fuhrman grade. CT perfusion appeared to be a non-invasive means to predict high Fuhrman grade of pT1b RCC preoperatively and guide the optimal treatment for the patient.

Diagnostic value of [18F] FDG-PET and PET/CT in urinary bladder cancer: a meta-analysis.

An early diagnosis of urinary bladder cancer is crucial for early treatment and management. The objective of this systematic review was to assess the overall diagnostic accuracy of 18 F FDG-PET and PET/CT in urinary bladder cancer with meta-analysis. The PubMed and CNKI databases were searched for the eligible studies published up to June 01, 2014. The sensitivity, specificity, and other measures of accuracy of 18 F FDG-PET and PET/CT in the diagnosis of urinary bladder cancer were pooled along with 95 % confidence intervals (CI). Summary receiver operating characteristic (ROC) curves were used to summarize overall test performance. Ten studies met our inclusion criteria. The summary estimates for 18 F FDG-PET and PET/CT in the diagnosis of urinary bladder cancer in meta-analysis were as follows: a pooled sensitivity, 0.82 (95 % confidence interval [CI], 0.75 to 0.88); a pooled specificity, 0.92 (95 % CI, 0.87 to 0.95); positive likelihood ratio, 6.80 (95 % CI, 4.31 to 10.74); negative likelihood ratio, 0.27 (95 % CI, 0.19 to 0.36); and diagnostic odds ratio, 25.18 (95 % CI, 17.58 to 70.4). The results indicate that 18 F FDG-PET and PET/CT are relatively high sensitive and specific for the diagnosis of urinary bladder cancer.