Peng Weijun

Application of 1.5 T magnetic resonance imaging in endometrial cancer

ObjectiveTo determine the diagnostic accuracy, sensitivity and specificity of magnetic resonance imaging (MRI) in detecting myometrial invasion, cervical involvement and disease stage in endometrial cancer.Methods168 consecutive patients with endometrial carcinoma underwent preoperative MRI. We classified myometrial invasion as no invasion, ≤50% invasion or >50% invasion and cervical involvement as positive or negative. The preoperative MRI findings and stagings were compared with final surgical and histological staging; the latter was taken as the gold standard. Standard statistical calculations were used.ResultsThe sensitivity, specificity, and accuracy of MRI for the detection of myometrial invasion >50% were 64.7, 92.5, and 86.9%, respectively. Positive and negative predictive values were 68.8 and 91.2%, respectively. The sensitivity, specificity, and accuracy of MRI for the detection of cervical invasion were 52.63, 93.08, and 83.93%, respectively. Positive and negative predictive values were 68.97 and 87.05%, respectively. 102 cases were classified as stage IA (early disease) by histology. MRI accurately predicted the degree of invasion in 88 cases and overestimated in 14, giving a sensitivity of 86.3% and specificity of 69.1%. However, MRI showed reduced sensitivity for predicting stage IB and advanced endometrial cancer (stages III and IV) at 33.3 and 30.3%, respectively, but was found to be specific for predicting these stages; the specificity were 94.7 and 85.1%, respectively. MRI also showed good accuracy for predicting stage IA, IB, II and advanced endometrial cancer at 80.4, 86.9, 91.7, and 83.9, respectively.ConclusionMRI assists in planning the surgical treatment of endometrial cancer with good accuracy and specificity, although sensitivity is suboptimal.

Differentiation of prostate cancer and stromal hyperplasia in the transition zone with histogram analysis of the apparent diffusion coefficient

Background Prostate cancer and stromal hyperplasia (SH) in the transition zone (TZ) are difficult to discriminate by conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI). Purpose To investigate the apparent diffusion coefficient (ADC) of prostate cancer and SH in the TZ with histogram analysis and the ability of ADC metrics to differentiate between these two tissues. Material and Methods Thirty-three cancer and 29 SH lesions in the TZ of 54 patients undergoing preoperative DWI (b-value 0, 1000 s/mm2) were analyzed. All the lesions on the MR images were localized based on histopathologic correlations. The 10th, 25th, and 50th percentiles, and the mean ADC values were calculated for the two tissues and compared. The efficiencies of the 10th, 25th, and 50th ADC percentiles in differentiating the two tissues were compared with that of the mean ADC with receiver operating characteristic (ROC) analysis. Results The 10th, 25th, and 50th percentiles and mean ADC values (×10−3 mm2/s) were 0.86 ± 0.15, 0.89 ± 0.16, 0.94 ± 0.16, and 1.03 ± 0.17 in SH and 0.64 ± 0.12, 0.69 ± 0.12, 0.72 ± 0.16, and 0.83 ± 0.15 in TZ cancer, respectively. The parameters were all significantly lower in cancer than SH. The 10th ADC percentile yielded an area under the ROC curve (AUC) of 0.87 for the differentiation of carcinomas from SH, which was higher than the mean ADC (0.80) (P < 0.05), and the AUCs of the 25th (0.82) and 50th (0.83) percentiles exhibited no differences from those of the mean ADC (P > 0.05). Conclusion Histogram analysis of ADC values may potentially improve the differentiation of prostate cancer from SH in the TZ.