OBJECTIVE. The objective of this study was to assess the long-term natural history of focal confluent fibrosis in cirrhotic liver with CT.MATERIALS AND METHODS. Two radiologists retrospectively reviewed in consensus 118 liver CT examinations in 26 patients (19 men, seven women; age range, 32–68 years; mean age, 50 years) performed over approximately 6 years. Helical CT scans were obtained before and 30–35 and 65–70 seconds after injection of 125–150 mL of contrast medium at a rate of 4–5 mL/s. Proof of cirrhosis was based on liver transplantation (n = 6), biopsy (n = 9), or imaging findings (n = 11). The number, location, and attenuation of fibrotic lesions and presence of trapped vessels were evaluated. Variation of hepatic retraction associated with the development of focal confluent fibrosis lesions was assessed using the ellipsoid volume formula and an arbitrary retraction index.RESULTS. Each radiologist identified 41 focal confluent fibrosis lesions. All lesions were identified by both radiologists. ...
Cystic renal lesions are a common incidental finding on routinely imaging examinations. Although a benign simple cyst is usually easy to recognize, the same is not true for complex and multifocal cystic renal lesions, whose differential diagnosis includes both neoplastic and non-neoplastic conditions. In this review, we will show a series of cases in order to provide tips to identify benign cysts and differentiate them from malignant ones.
The aim of this study was to evaluate MR imaging changes of the pancreas in patients with transfusion-dependent beta-thalassemia major.Twenty patients with transfusion-dependent beta-thalassemia major were examined using MR imaging at 0.5 T, with spin-echo T1-weighted, fast spin-echo T2-weighted, and gradient-echo T2*-weighted sequences. Image analysis was performed to assess pancreas-to-fat signal intensity ratios for all pulse sequences. Pancreatic exocrine and endocrine function and serum ferritin levels were assessed. Twenty healthy volunteers underwent MR imaging with the same three sequences and served as a control group.The pancreas-to-fat signal intensity ratio was significantly decreased in 17 (85%) of the 20 patients on spin-echo T1-weighted images (p < .05), fast spin-echo T2-weighted images (p < .01), and gradient-echo T2*-weighted images (p < .01) when compared with the 20 volunteers in the control group. The pancreas-to-fat signal intensity ratio was significantly increased in three (15%) of...
To assess the relationship between magnetic resonance (MR) imaging pituitary signal intensity reduction in patients with transfusional hemochromatosis and the clinical manifestation of hypogonadotropic hypogonadism. Pituitary MR imaging at 0.5 T was performed in 38 consecutive patients affected by secondary hemochromatosis and in 20 healthy volunteers. Serum ferritin levels were estimated in the affected population. Twenty (53%) of the 38 patients had hypogonadotropic hypogonadism diagnosed. Pituitary-to-fat signal intensity ratios were calculated from coronal gradient-echo (GRE) T2*-weighted MR images. The relationship between the quantitative reduction of the pituitary-to-fat signal intensity ratio and the clinical manifestation of pituitary dysfunction was assessed in the affected population. Signal intensity reduction in the anterior lobe of the pituitary gland was also correlated with the serum ferritin level. The degree of reduction of the pituitary-to-fat signal intensity ratio correlated with the presence of hypogonadotropic hypogonadism, with a sensitivity of 90%, a specificity of 89%, and an overall accuracy of 89%. In addition, the reduction of pituitary signal intensity was greater in patients with higher ferritin levels (r = -0.55, r(2) = -0.30, P <.001). The degree of signal intensity reduction, measured as the pituitary-to-fat signal intensity ratio for GRE T2*-weighted images, in patients with secondary hemochromatosis correlates with the severity of pituitary dysfunction.
The purpose of this study was to assess the accuracy of susceptibility-weighted imaging (SWI), compared with T2*-weighted gradient echo (GRE) imaging in assessing cerebral cavernous malformations. We retrospectively evaluated 21 patients with a familial form of cavernous malformation. Magnetic resonance (MR) protocol included non-enhanced and contrast-enhanced fast-spin echo (FSE) T1-weighted sequences, FSE T2-weighted sequences, fluid-attenuated inversion-recovery (FLAIR), GRE T2*-weighted and SWI sequences. Images were reviewed in consensus by two expert neuroradiologists to assess the location, number, size and conspicuity of the lesions on T2*-weighted GRE and SWI sequences. Statistical differences in the number, size and conspicuity of the lesions seen on the SWI images and the T2*-weighted GRE images were assessed with the nonparametric Wilcoxon signed rank test. The number of cavernous malformations was significantly higher (p < .001) on the SWI images (n = 152) than on T2*-weighted GRE images (n = 56). Lesion size was significantly higher (p < .001) on SWI images (mean: 0.4 cm, SD ± 0.55) than on T2*-weighted GRE sequences (mean: 0.2 cm, SD ± 0.51) and the differences were statistically significant (p < .001). Lesion conspicuity was significant higher (p < .001) on SWI than on T2*-weighted GRE images. In one patient who underwent a 2-month follow-up for the onset of neurologic symptoms related to cerebral hemorrhage, a cerebral hematoma was identified at the site of a cerebral cavernous malformation that was demonstrated only on the SWI images in the previous MR examination. The SWI sequence, being more sensitive to substances which distort the local magnetic field than the GRE T2*W sequence, showed a higher sensitivity in identifying cerebral cavernous malformations. Thus, routine clinical neuroimaging protocol should contain SWI sequences to evaluate patients with (or suspected) cerebral cavernous malformations.
The use of two different educator-centric learning management systems (LMSs), Moodle and Manila, for radiology e-learning was formatively evaluated and the implications of the future use of LMSs in radiology education were explored. NeuroRAD, a neuroradiologic digital library and learning community, is implemented with Moodle, one of the most popular open-source educator-centric LMSs. Pediatric-Education.org, a pediatric digital library and learning community, is implemented with Manila, a commercial educator-centric LMS. Quantitative and qualitative analyses of these LMSs were performed with World Wide Web server log file statistical programs and user-submitted comment forms. In 2005, NeuroRAD was used by 9959 visitors, who read 98,495 pages of information, whereas PediatricEducation .org was used by 91,000 visitors, who read 186,000 pages of information. Visitors represented a wide spectrum of medical learners and used the sites to answer clinical questions; to prepare for lectures, conferences, and informal teaching sessions; and to stay up-to-date and prepare for examinations. Early results indicate that radiology learning communities can be implemented with educator-centric LMSs relatively easily and at low cost by radiologists with minimal computer expertise, and can find receptive and appreciative audiences. Online radiology learning communities could play a significant role in providing education to radiologists the world over throughout their careers.