DWI is a feasible technique that can be used for the differentiation of malignant and benign tissues in the PZ and TZ. Additionally, T2WI with DWI is superior to T2WI alone for the prediction of prostate cancer location.

No abstract

The 3.0-T phased-array MRI is equivalent to the 1.5-T endorectal MRI in evaluating local staging accuracy for prostate cancer without significant loss of imaging quality.

These results demonstrate the presence and localization of a specialized nail mesenchyme containing onychofibroblasts in a well-defined area beneath the nail matrix and nail bed. Thus, we propose the term onychodermis for this specialized nail mesenchyme that is histologically and immunohistochemically distinct from the dermis of other parts of the nail unit.

Integrated fluorine-18 fluorodeoxyglucose positron emission tomography (PET)-computed tomography (CT) for adrenal gland imaging in cancer patients allows early detection and accurate localization of adrenal lesions and differentiation of metastatic nodules from benign lesions, thereby facilitating treatment planning. However, false-positive findings are encountered at integrated PET-CT in approximately 5% of adrenal lesions identified as positive at PET, including adrenal adenomas, adrenal endothelial cysts, and inflammatory and infectious lesions. Moreover, false-negative findings may be seen in adrenal metastatic lesions with hemorrhage or necrosis, small-sized (<10-mm) metastatic nodules, and metastases from pulmonary bronchioloalveolar carcinoma or carcinoid tumors. An awareness of the potential pitfalls of integrated PET-CT enhances the diagnostic efficacy of this modality by allowing differentiation of metastatic adrenal lesions from other abnormalities.

Increase in the number of scattered atypical melanocytes with large hyperchromatic nuclei in a partial nail matrix may provide a diagnostic clue to subungual melanoma in situ in concert with its clinical suspicion.

ObjectiveTo retrospectively determine the optimal b value of diffusion-weighted imaging (DWI) for predicting the presence of localized prostate cancer, and to evaluate the utility of DWI under different b values in differentiating between cancers and benign prostatic tissues.Materials and MethodsEighty patients with suspected prostate cancer underwent MRI including DWI at 3T, followed by radical prostatectomy. DWI was examined under different b values. Apparent diffusion coefficient (ADC) maps were generated by using b = 0, and other b values of 300, 700, 1000 or 2000 s/mm2. For predicting the presence of cancers, four different ADC maps were analyzed independently by two blinded readers. ADCs were measured in benign and malignant tissues.ResultsFor predicting the presence of 110 prostate cancers, the sensitivity and area under the curve (AUC) for an experienced reader was significantly greater at b = 1000 (85% and 0.91) than b = 300, 700 or 2000 s/mm2 (p < 0.01). For a less-experienced reader, the AUC was significantly greater at b = 700, 1000 or 2000 than b = 300 s/mm2 (p < 0.01). Mean ADCs of the cancers in sequence from b = 300 to 2000 s/mm2 were 1.33, 1.03, 0.88 and 0.68 × 10-3 mm2/s, which were significantly lower than those of benign tissues (p < 0.001).ConclusionThe optimal b value for 3T DWI for predicting the presence of prostate cancer may be 1000 s/mm2.

The purpose of this study was to retrospectively evaluate the enhancement washout and other imaging features of pheochromocytomas on delayed contrast-enhanced CT. Twenty-four patients with 31 pathologically confirmed pheochromocytomas were examined using unenhanced, early and delayed contrast-enhanced CT. The range of their APEW (absolute percentage of enhancement washout) or RPEW (relative PEW) values was analyzed. The other CT features including cystic or necrotic change, calcification, and hemorrhage were also determined by a pathologic correlation. Of the 31 pheochromocytomas, 10 (32%) had APEW values of 60% or less and RPEW values of 40% or less. Fourteen (45%) had APEW values >60% and RPEW values >40%. CT showed cystic or necrotic changes in 11 pheochromocytomas (35%) and calcification (10%) in 3. Nineteen pheochromocytomas showed cystic or necrotic changes on early contrast-enhanced CT, but eight of these lesions showed late enhancement on delayed contrast-enhanced CT, which pathologically corresponded to myxoid degeneration. The unenhanced CT showed hemorrhage in 23 pheochromocytomas, but the pathology examinations showed hemorrhage in 15 lesions. Many pheochromocytomas can be misdiagnosed as adenomas on CT due to the high enhancement washout values. Delayed contrast-enhanced CT can detect myxoid degeneration with late enhancement, which is seen as a cystic or necrotic change on early contrast-enhanced CT.