Accuracy of MRI/MRSI-based transrectal ultrasound biopsy in peripheral and transition zones of the prostate gland in patients with prior negative biopsy.

The purpose of the study was to evaluate the accuracy of transrectal ultrasound biopsy (TRUS-biopsy) performed on regions with abnormal MRI and/or MRSI for both the transition (TZ) and the peripheral (PZ) zones in patients with suspected prostate cancer with prior negative biopsy, and to analyze the relationship between MRSI and histopathological findings. MRI and MRSI were performed in 54 patients (mean age: 63.9 years, mean PSA value: 11.4 ng/mL) and the ability of MRI/MRSI-directed TRUS biopsy was evaluated. A three-point score system was used for both techniques to distinguish healthy from malignant regions. Descriptive statistics and ROC analyses were performed to evaluate the accuracy and the best cut-off in the three-point score system. Twenty-two out of 54 patients presented cancer at MRI/MRSI-directed TRUS biopsy, nine presented cancer only in PZ, eight both in PZ and TZ, and five exclusively in TZ. On a patient basis the highest accuracy was obtained by assigning malignancy on a positive finding with MRSI and MRI even though it was not significantly greater than that obtained using MRI alone (area under the ROC curve, AUC: 0.723 vs 0.676). On a regional (n = 648) basis the best accuracy was also obtained by considering positive both MRSI and MRI for PZ (0.768) and TZ (0.822). MRSI was false positive in 11.9% of the regions. Twenty-eight percent of cores with prostatitis were false positive findings on MRSI, whereas only 2.7% of benign prostatic hyperplasia was false positive. In conclusion, the accuracy of MRI/MRSI-directed biopsies in localization of prostate cancer is good in patient (0.723) and region analyses (0.768). The combination of both MRI and MRSI results makes TRUS-biopsy more accurate, particularly in the TZ (0.822) for patients with prior negative biopsies. Histopathological analysis showed that the main limitation of MRSI is the percentage of false positive findings due to prostatitis.

Characterization of small nodules in cirrhosis by assessment of vascularity: the problem of hypovascular hepatocellular carcinoma.

In a prospective study, we examined the impact of arterial hypervascularity, as established by the European Association for the Study of the Liver (EASL) recommendations, as a criterion for characterizing small (1-3 cm) nodules in cirrhosis. A total of 72 nodules (1-2 cm, n = 41; 2.1-3 cm, n = 31) detected by ultrasonography in 59 patients with cirrhosis were included in the study. When coincidental arterial hypervascularity was detected at contrast perfusional ultrasonography and helical computed tomography, the lesion was considered to be hepatocellular carcinoma (HCC) according to EASL criteria. When one or both techniques showed negative results, ultrasound-guided biopsy was performed. In cases with negative results for malignancy or high-grade dysplasia, biopsy was repeated when an increase in size was detected at the 3-month follow-up examination. Coincidental hypervascularity was found in 44 of 72 nodules (61%; 44% of 1-2-cm nodules and 84% of 2-3-cm nodules). Fourteen nodules (19.4%) had negative results with both techniques (hypovascular nodules). Biopsy showed HCC in 5 hypovascular nodules and in 11 of 14 nodules with hypervascularity using only one technique. All nodules larger than 2 cm finally resulted to be HCC. Not satisfying the EASL imaging criteria for diagnosis were 38% of HCCs 1 to 2 cm (17% hypovascular) and 16% of those 2 to 3 cm (none hypovascular). In conclusion, the noninvasive EASL criteria for diagnosis of HCC are satisfied in only 61% of small nodules in cirrhosis; thus, biopsy frequently is required in this setting. Relying on imaging techniques in nodules of 1 to 2 cm would miss the diagnosis of HCC in up to 38% of cases. Any nodule larger than 2 cm should be regarded as highly suspicious for HCC.