Neslihan Tasdelen

Diffusion-weighted imaging of the renal and adrenal lesions.

Objectives: The purpose of this study was to calculate the apparent diffusion coefficient (ADC) values of different renal and adrenal lesions to evaluate the ability of diffusion-weighted imaging in characterizing masses and determining malignancy. Methods: A total of 52 patients consisting of 67 renal lesions and 28 patients with 33 adrenal lesions in addition to 50 healthy controls with normal kidneys were enrolled in the study. Diffusion-weighted imaging was performed with b factors of 0, 500, and 1000 s/mm2, and the ADCs of the normal kidney and renal and adrenal lesions were calculated. Results: The mean (SD) ADCs of the renal cortex and medulla of the control group were 2.08 (0.22) × 10−3 and 1.94 (0.18) × 10−3 mm2/s, respectively. Focal renal lesions were as follows: simple cysts (2.94 [0.20] × 10−3 mm2/s), hemorrhagic cysts (1.71 [0.38] × 10−3 mm2/s), angiomyolipomas (1.40 [0.21] × 10−3 mm2/s), renal cell carcinomas (1.06 [0.39] × 10−3 mm2/s), metastases (1.50 [0.13] × 10−3 mm2/s), and hydronephrosis (1.54 [0.25] × 10−3 mm2/s). The mean ADCs of all these pathologies were significantly different when compared with normal parenchyma. Diffusion-weighted imaging was also able to differentiate angiomyolipomas and hemorrhagic cysts from renal cell carcinomas. Adrenal lesions were subgrouped as adenomas (1.41 [0.27] × M10−3 mm2/s), nonadenomatous solid masses (1.08 [0.28] × 10−3 mm2/s), and cysts (2.82 [0.24] × 10−3 mm2/s). The mean ADCs of adenomas were significantly different when compared with nonadenomatous solid masses and cysts. Conclusions: Our findings show that ADC measurement has a potential ability to differentiate benign and malignant focal renal and adrenal lesions with the guidance of conventional sequences. When used alone, diffusion-weighted imaging may lead to misdiagnoses due to overlapping ADCs of the lesions.

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.

Diagnostic utility of DTI in prostate cancer

PURPOSE The aim of this study was to compare the diffusion tensor parameters of prostate cancer, prostatitis and normal prostate tissue. MATERIALS AND METHODS A total of 25 patients with the suspicion of prostate cancer were included in the study. MRI was performed with 3 T system (Intera Achieva, Philips Medical Systems, The Netherlands). T2 TSE and DTI with ss-EPI were obtained in each subject. TRUS-guided prostate biopsy was performed after the MRI examination. Images were analyzed by two radiologists using a special software system. ROIs were drawn according to biopsy zones which are apex, midgland, base and central zone on each sides of the gland. FA and ADC values in areas of cancer, chronic prostatitis and normal prostate tissue were compared using Students t-test. RESULTS Histopathological analysis revealed carcinoma in 68, chronic prostatitis in 67 and was reported as normal in 65 zones. The mean FA of cancerous tissue was significantly higher (p<0.01) than the FA of chronic prostatitis and normal gland. The mean ADC of cancerous tissue was found to be significantly lower (p<0.01), compared with non-cancerous tissue. CONCLUSION Decreased ADC and increased FA are compatible with the hypercellular nature of prostate tumors. These differences may increase the accuracy of MRI in the detection of carcinoma and to differentiate between cancer and prostatitis.

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-weighted imaging of adnexal torsion

We report the diffusion-weighted imaging findings (DWI) of a case with ovarian torsion. Magnetic resonance imaging revealed a large cyst within a non-enhancing ovary. DWI depicted restricted diffusion which in turn was found to be related with the infarction of the ovary in the laparoscopic salpingo-oophorectomy performed.

The Evaluation of Saphenofemoral Insufficiency in Primary Adult Varicocele

The aim of this study was to evaluate the possible relationship between varicocele and saphenofemoral insufficiency in patients diagnosed with primary varicocele. A total of 70 patients with the primary diagnosis of varicocele were included into the study. A total of 30 age-matched healthy adults were also included in the study as a control group. Varicocele was diagnosed by palpation and observation of each spermatic cord in standing position before and during a valsalva maneuver. Additionally, scrotal Doppler and lower extremity venous Doppler ultrasonography were performed. Patients who were with spermatic varicose vein larger than 3.0 mm were included in the study group as a varicocele patient. At the lower extremity venous Doppler ultrasonography, a retrograde flow lasting longer than 0.5 seconds during normal breathing or at the valsalva maneuver was considered to be meaningful for saphenofemoral junction insufficiency. Thirty-six (51.35%) patients had insufficiency in saphenofemoral junction in the study group (6 [8.5%] bilateral, 30 [42.85%] unilateral) whereas 8 (26.6%) had insufficiency in the control group (2 [6.6%] bilateral, 6 [20%] unilateral insufficiency). The patients with primary varicocele had a statistically significant (P = .02) higher rate of venous insufficiency in their saphenofemoral junctions when compared with the control group. In the present study, the rate of saphenofemoral insufficiency has been found to be statistically higher in patients with primary varicocele compared with healthy men. Depending on the common presence of valvular insufficiency, we believe that the presence of varicocele should be investigated in the young population suffering from saphenofemoral junction insufficiency.

Diffusion tensor imaging in carpal tunnel syndrome.

PURPOSE We aimed to investigate the efficacy of diffusion tensor imaging in the diagnosis of carpal tunnel syndrome and to obtain a quantitative parameter that may contribute to the diagnosis. MATERIALS AND METHODS The median nerves in 57 wrists of 38 patients diagnosed as carpal tunnel syndrome and 30 wrists of 24 normal subjects were prospectively evaluated with a 3T Philips scanner, using standard 8-channel SENSE head coil. Diffusion tensor imaging was performed using spin echo-echo planar imaging. For anatomical reference, a T1-weighted sequence was acquired. Fractional anisotropy and apparent diffusion coefficient measurements were done focally at the carpal tunnel level and from whole median nerve. RESULTS In carpal tunnel syndrome patients, both focal carpal tunnel and whole nerve measurements demonstrated statistically significantly lower fractional anisotropy values than normal subjects (P < 0.001). No statistically significant difference was observed in apparent diffusion coefficient measurements. The cut-off value obtained by receiver operator characteristics analysis was 0.554 for focal carpal tunnel fractional anisotropy (sensitivity, 80%; specificity, 80%) and 0.660 for whole nerve fractional anisotropy (sensitivity, 82%; specificity, 80%) measurement. CONCLUSION Diffusion tensor imaging may contribute to the diagnosis of carpal tunnel syndrome on the basis of fractional anisotropy measurements.

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.

Cystic thigh mass in an 18 year old girl: diagnosis and discussion.

Magnetic resonance imaging (MRI) of the thigh revealed a cystic mass with multiple smaller cysts consistent with daughter cysts. The wall of the parent cyst was hypointense on T2-weighted image and enhanced following contrast material administration. The enhancement of the parent cyst wall was related to the inflammatory changes of the surroinding tissues and also because of the blood vessels providing nutrients to the parasite. The walls of the daughter cysts were not discernible in addition they did not enhance since they were non-vascularized free floating cystic structures in the parent cyst. Diffusion-weighted imaging (DWI) revealed restricted diffusion of the parent cyst. In contrast diffusion was increased in the daughter cysts. Histopathological examination of the cystic mass revealed scolices in laminated fibrous wall of hydatid cyts. The final diagnosis was multivesicular hydatid cyst of the thigh.

A new MRI grading system for chondromalacia patellae.

Background Chondromalacia patellae is a very common disorder. Although magnetic resonance imaging (MRI) is widely used to investigate patellar cartilage lesions, there is no descriptive MRI-based grading system for chondromalacia patellae. Purpose To propose a new MRI grading system for chondromalacia patellae with corresponding high resolution images which might be useful in precisely reporting and comparing knee examinations in routine daily practice and used in predicting natural course and clinical outcome of the patellar cartilage lesions. Material and Methods High resolution fat-saturated proton density (FS PD) images in the axial plane with corresponding T2 mapping images were reviewed. A detailed MRI grading system covering the deficiencies of the existing gradings has been set and presented on these images. Two experienced observers blinded to clinical data examined 44 knee MR images and evaluated patellar cartilage changes according to the proposed grading system. Inter- and intra-rater validity testing using kappa statistics were calculated. Results A descriptive and detailed grading system with corresponding FS PD and T2 mapping images has been presented. Inter-rater agreement was 0.80 (95% confidence interval [CI], 0.71–0.89). Intra-rater agreements were 0.83 (95% CI, 0.74–0.91) for observer A and 0.79 (95% CI, 0.70–0.88) for observer B (k-values). Conclusion We present a new MRI grading system for chondromalacia patellae with corresponding images and good inter- and intra-rater agreement which might be useful in reporting and comparing knee MRI examinations in daily practice and may also have the potential for using more precisely predicting prognosis and clinical outcome of the patients.