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Objective: Currently, it is unclear whether pheochromocytomas can be ruled out based on low intensity on T2-weighted sequences and signal loss on out-of-phase magnetic resonance imaging (MRI) sequences. Hence, in this study, we investigated whether biochemical screening for pheochromocytoma in patients with adrenal incidentalomas (AIs) showing MRI features not suggesting pheochromocytoma would prove beneficial., Methods: We performed MRI for 300 AIs in 278 consecutive patients. All patients were screened for pheochromocytoma with plasma metanephrine and normetanephrine. Patients with high plasma levels of metanephrine and/or normetanephrine were also assessed for pheochromocytoma by urinary metanephrines., Results: Hyperintensity was detected on T2-weighted MRI sequences in 28 (9.3%) of the 300 AIs. Among these 28 incidentalomas, pheochromocytoma was diagnosed in 13 (46.4%) of the cases by histopathologic analysis. Hyperintensity on T2-weighted MRI was significantly higher in pheochromocytomas compared to the remaining AIs (P<.001). All 13 pheochromocytomas were characterized by hyperintensity on T2-weighted sequences and the absence of signal loss on out-of-phase MRI sequences. Pheochromocytoma was not detected in any of the 272 AIs that appeared hypointense or isointense on T2-weighted MRI sequences or in the 250 cases with signal loss on out-of-phase sequences., Conclusion: The results of this study suggest that AIs that appear hypointense or isointense on T2-weighted MRI sequences and those with signal loss on out-of-phase sequences may not require routine biochemical screening for pheochromocytoma. Further studies including a higher number of pheochromocytomas are required to confirm our results.

Ectopic cervical thymus (ECT) is an uncommon cause for cervical mass in the pediatric age group. Ultrasound and magnetic resonance imaging findings of the mass (located along the thymic descent pathway along the thymopharyngeal tract and has identical echostructure and signal intensities to the native thymus in the superior mediastinum) would lead to the diagnosis. The diagnosis is confirmed by fine needle aspiration biopsy or histopathology after resection. The management of ECT is a conservative follow up, except in symptomatic cases with tracheal compression and histologically confirmed neoplasia where surgery is indicated. We present the case of ECT presenting as a left upper neck mass in a 12 year old girl.

Background: Although diffusion-weighted magnetic resonance imaging imaging (DW-MRI) is commonly used to characterize hepatic lesions, the literature is sparse about the use of MR diffusion tensor imaging (DTI) in this regard. By using DTI, one is able to obtain not only apparent diffusion coefficients (ADCs) but also fractional anisotropy (Fa) values., Purpose: To evaluate DTI using ADC and Fa values in the imaging of hepatic cysts, hemangiomas, and metastases., Material and Methods: Sixty-six patients with 77 lesions were examined with DTI. There were 32 metastases, 13 cysts, and 32 hemangiomas. Two radiologists performed ADC and Fa measurements. Inter-observer agreement was evaluated using Bland-Altman plots. ADCs and Fa values were correlated using Pearson correlation. The differences were compared using ANOVA and Tukey tests. A ROC analysis was applied; sensitivities and specificities were calculated., Results: The inter-observer agreement was very good. The correlation between ADC and Fa was negative, weak, and significant (r = -0.36). The mean ADC value of cysts (3.30 ± 0.8 × 10(-3) mm(2)/s) was significantly higher than that of hemangiomas (2.23 ± 0.5 × 10(-3) mm(2)/s) and metastases (1.62 ± 0.4 × 10(-3) mm(2)/s). The mean Fa value of cysts (0.2 ± 0.05) was significantly lower than hemangiomas (0.37 ± 0.1) and metastases (0.46 ± 0.1). The Az values for discriminating metastases from benign hepatic lesions for ADC and Fa value were 0.885 and 0.731, respectively. The sensitivity and specificity of ADC and Fa were 87.5% and 84.4%, and 78.1% and 57.8%, respectively. The Az value for discriminating cysts from hemangiomas for Fa was 0.96. The sensitivity and specificity were 90.6% and 92.3%, respectively., Conclusion: Fa values may play a supportive role in the imaging of liver lesions. Whereas metastases tend to have low ADCs and high Fa values, cysts have high ADCs and low Fa values and hemangiomas have high ADCs and high Fa values., (© The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Aim: To investigate the role of Diffusion-weighted magnetic resonance imaging and apparent diffusion coefficient (ADC) values in the differential diagnosis of solid lesions of the breast. Materials and Methods: Diffusion-weighted images and ADC values from 36 women with 37 solid lesions definitely diagnosed through breast biopsy and post-surgical histopathology were evaluated retrospectively. ADC values obtained from malignant and benign solid lesions of the breast were compared using the t-test. The optimum threshold value for use in differentiating benign and malignant lesions was determined using ROC analysis, and sensitivity and specificity values were calculated.Results: Histological analysis identified 23 lesions and 14 benign lesions. Mean age (49 ± 7.8 years) was higher in the group with malignant breast lesions than in the group with benign breast lesions (37.3 ± 8.2) (p 0.05). The mean ADC value (1.1 ± 0.2 × 10-3 mm2/s) in the patients with malignant breast lesions was significantly lower than in the group with benign breast lesions (1.49 ± 0.18 × 10-3 mm2/s) (p 0.05). When the threshold value to be used in the ROC curve was applied the differentiation of benign and malignant solid lesions, the sensitivity was 78.3% and specificity was 100%.Conclusions: Diffusion-weighted MRI and ADC values have the potential to contribute to the diagnosis of solid lesions in the breast at conventional MR examination by differentiating between benign and malignant tumors. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the role of magnetic resonance (MR) diffusion tensor imaging (DTI) in the assessment of liver fibrosis and inflammation in chronic viral hepatitis by measuring apparent diffusion coefficient (ADC) and fractional anisotropy (Fa) values. Material and Methods: Twenty-seven patients (5 women and 22 men;mean age39.8±11.3) with hepatic fibrosis were included in our study. The relationship between ADC, Fa values and histological activity index (HAI) score were evaluated using Spearman's correlation coefficient. Patients were subgrouped as group A (fibrosis score 1) and group B (fibrosis score 3). The mean ADC and Fa values of groups A and B were compared using Student's t-test. To evaluate the use of ADC and Fa values in distinguishing group A from group B, ROC analysis was applied; sensitivities and specificities were calculated. Results: Fa values correlated with HAI scores significantly (r=0.397, p<0.05) The difference was significant between the mean ADC values (group A:1.46± 0.191x103mm2/s; group B:1.105± 0.141x10-3 mm2/s; p<0.001) and Fa values (group A: 0.473±0.091; group B: 0.643± 0.007; p<0.001) between the groups. For distinguishing group A from group B, ADC had a sensitivity of 81.8% and a specificity of 93.8%. The sensitivity and specificity of Fa were 90.9% and 100%, respectively. Conclusion: Diffusion tensor imaging may play a role in the evaluation of fibrosis and HAI scores in patients with liver fibrosis. [ABSTRACT FROM AUTHOR]

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