Standard b-value versus low b-value diffusion-weighted MRI in renal cell carcinoma: a systematic review and meta-analysis.

BACKGROUND: We sought to determine the comparative diagnostic performance of standard b-value (800-1000 s/mm2) versus low b-value (400-500 s/mm2) diffusion-weighted magnetic resonance imaging (DW-MRI) in the detection of renal cell carcinoma (RCC). METHOD: After a systematic review of the available literature, studies were included that reported b-values, used a histopathological reference standard, and allowed construction of 2 × 2 contingency tables for detection of RCC lesions using DW-MRI. In addition, a summary receiver operating characteristic (SROC) analysis was performed. RESULTS: Four articles that complied with all inclusion and exclusion criteria were selected for data extraction and analysis (n = 248 lesions in 266 patients). All four studies were high quality. Standard b-value DW-MRI displayed a pooled sensitivity of 0.59 (95% confidence interval (CI): 0.51-0.67) and a pooled specificity of 0.50 (95% CI: 0.30-0.70), while low b-value DW-MRI displayed a pooled sensitivity of 0.58 (95% CI: 0.48-0.63) and a pooled specificity of 0.23 (95% CI: 0.09-0.44). The SROC curve of standard b-value DW-MRI displayed an AUC of 0.61 and a Q*index of 0.59, while the SROC curve of low b-value DW-MRI displayed an AUC of 0.68 and a Q*index of 0.64. CONCLUSION: Standard b-value DW-MRI showed a superior specificity but an approximately equivalent sensitivity to low b-value DW-MRI in detecting RCC lesions in the kidney. However, low b-value DW-MRI displayed an overall superior diagnostic accuracy over standard b-value DW-MRI.

Pulse pressure correlates with coronary artery calcification and risk for coronary heart disease: a study of elderly individuals in the rural region of Southwest China.

AIM: This study aimed to define the relationship between pulse pressure (PP) and coronary artery calcification (CAC), a proven surrogate marker for coronary heart disease. PATIENTS AND METHODS: A total of 170 participants 50-70 years of age from 11 villages of Yunnan Province of China were enrolled randomly into this study. They were examined routinely for diastolic and systolic blood pressure, PP, and CAC. RESULTS: The average PP in the CAC-positive group was significantly higher than that in the CAC-negative group. In the positive CAC group, there were significantly positive correlations between PP and CAC score, volume, mass, as well as density. The area under the receiver operating characteristic curve analysis showed that PP performed well in predicting CAC. CONCLUSION: In conclusion, among the rural people of southwest of China, PP correlates positively with the coronary calcium Agatston score, volume, mass, and density. PP predicted CAC as well as Framingham Risk Score. The measurement of PP widening may serve as an alternative and convenient method for assessing CAC risk in rural populations with poor accessibility and economic disadvantage over coronary computed tomography scanning.