Nevzat Gürmen

Diffusion-weighted imaging of the rectosigmoid colon: preliminary findings.

Objectives: The aims of this study were to determine and evaluate the apparent diffusion coefficient (ADC) values of the rectal wall for identifying inflammatory bowel disease (IBD) and rectosigmoid (rectum and sigmoid colon) malignancies. Methods: Diffusion-weighted magnetic resonance imaging (DWI) findings of 23 patients (mean age, 57 years) consisting of 14 patients with rectosigmoid adenocarcinomas and 9 patients with IBD (6 with ulcerative colitis and 3 with Crohn disease) were retrospectively reviewed. In addition, 30 healthy controls (mean age, 45 years) were enrolled in the study. Diffusion-weighted imaging was performed with b factors of 0, 500, and 1000 s/mm2. Results: The mean (SD) ADC values of the control, IBD, and rectosigmoid adenocarcinoma groups were 1.47 (0.19) × 10−3 mm2/s, 1.37 (0.12) × 10−3 mm2/s, and 0.97 (0.14) × 10−3 mm2/s, respectively. Among the patients with IBD, 2 were in the active, and the rest were in the inactive period, with mean (SD) ADC values of 1.21 (0.08) × 10−3 and 1.42 (0.09) × 10−3, respectively. The ADC values of the normal rectum and rectosigmoid malignancy group and rectosigmoid carcinoma and IBD groups were significantly different (P < 0.01). A cutoff value for carcinomas of 1.14 × 10−3 mm2/s yielded a sensitivity and specificity of 93.3% and 93.3%, respectively. Conclusions: Our preliminary findings show that quantitative DWI may be able to differentiate the normal rectum from neoplastic involvement, in addition to distinguishing between inflammatory and neoplastic involvements. However, radiologists should be aware of possible overlaps that may lead to misdiagnoses when DWI is used alone.

Diffusion tensor imaging of the kidney at 3 Tesla: normative values and repeatability of measurements in healthy volunteers

PURPOSE To evaluate the feasibility of renal diffusion tensor imaging and determine the normative fractional anisotropy and apparent diffusion coefficient values at 3 Tesla magnetic resonance imaging (MRI) using parallel imaging and free breathing technique. MATERIALS AND METHODS A total of 52 young healthy volunteers with no history of renal disease were included in the study. MRI examinations were performed with 3 Tesla MRI equipment, using six-channel phased array SENSE Torso coil. In all subjects, T2-weighted turbo spin echo and diffusion tensor imaging using single shot echo planar imaging sequences were obtained in the coronal plane with free breathing. Field of view, slice thickness, and slice gap values were identical for both sequences for anatomic correlation during analysis of diffusion tensor imaging data. Parallel imaging method was used with a SENSE factor of 2. Diffusion tensor parameters of the cortex and medulla were determined and the intra- and inter-observer measurement variances were calculated. RESULTS The mean fractional anisotropy of the medulla was significantly higher than that of the cortex, whereas the mean apparent diffusion coefficient of the medulla was lower when compared with that of the cortex. According to the two-sided paired samples Students t test, the intra- and inter-observer measurements correlated well. CONCLUSION This study shows the feasibility of renal diffusion tensor imaging and repeatibility of diffusion tensor parameter measurements in 3 Tesla MRI.

Diffusion tensor imaging in the differentiation of adrenal adenomas and metastases.

PURPOSE To determine the utility of diffusion tensor imaging for the differentiation of adrenal adenomas and metastases. MATERIALS AND METHODS Thirty-three patients with a mean age of 59 years were included in this study. Each subject presented with a single adrenal lesion (19 adenomas, 14 metastases). Magnetic resonance imaging (MRI) was performed in the coronal plane using a 3 Tesla MRI and a six-channel phased array SENSE torso coil. T1-weighted in-phase and opposed-phase, T2-weighted turbo spin-echo, and single-shot echo-planar diffusion tensor imaging (DTI) sequences were used for image acquisition. To determine apparent diffusion coefficients (ADC) and fractional anisotropy (FA) values of adrenal lesions, coronal T2-weighted images were used as anatomical references and to localize regions of interest on DTI images. The signal intensity (SI) indices were obtained from in-phase/opposed-phase images by a radiologist blinded to the DTI findings. The DTI parameters were determined by a different radiologist. The SI indices and the differences in FA and ADCs between adenomas and metastases were compared. Analyses of receiver operating characteristics (ROC) were performed to determine the area under the curve (AUC). RESULTS The SI index of adenomas was found to be significantly higher than the value determined for metastases. Moreover, the median FA value of adrenal adenomas was found to be significantly higher than that of metastases. No statistically significant difference was observed in the ADCs between adenomas and metastases. Furthermore, no significant correlation was found among the SI index and the measured DTI parameters. Based on ROC analyses, the AUC was found to be 0.936 in FA measurements with a 95% confidence interval. The cutoff value obtained from this analysis was 0.40 with maximum sensitivity and specificity values of 74% and 88%, respectively. CONCLUSION Although no significant difference was observed in the ADCs between adrenal adenomas and metastases, the FA values differed significantly. The FA values may have the potential to differentiate between adrenal adenomas and metastases, which is a possibility that should be validated by further research.

Percutaneous ureterostomy as an effective diversion in a newborn

Abstract  Ectopic ureter in a duplicated system in men is rare and rarely causes bilateral obstructive symptoms. The tendency of the ureter to dilate more than the caliceal system is unique to neonates and makes upper urinary diversions more challenging. However, alternative percutaneous diversions other than nephrostomy might be beared in mind in such cases with huge dilatation in ureters in suffering neonates. As discussed in this case percutaneous ureterostomy may be very effective and have a role in diagnosis and management of neonatal hydroureteronephrosis.

Renal amyloidosis due to pulmonary tuberculosis in a patient with Down syndrome.

A pulmonary-tuberculosis-related renal amyloidosis patient with Down syndrome, who presented with nephrotic syndrome, was studied.

An unusual form of Gaucher’s disease: pulmonary and cardiovascular involvement and cholelitiasis

Gaucher’s disease is an inherited storage disease caused by a deficiency of the enzyme glucocerebrosidase. Although the hepatic manifestations are seen frequently, pulmonary and cardiovascular involvements are known to be very rare in Gaucher’s disease. This report presents these rare findings made by conventional radiography, computerized tomography (CT), and High-resolution CT (HRCT) of a 16-year-old female patient with fatal Gaucher’s disease.