Post-contrast T1-weighted sequences in pediatric abdominal imaging: comparative analysis of three different sequences and imaging approach.

BACKGROUND: Post-contrast T1-weighted imaging is an essential component of a comprehensive pediatric abdominopelvic MR examination. However, consistent good image quality is challenging, as respiratory motion in sedated children can substantially degrade the image quality. OBJECTIVE: To compare the image quality of three different post-contrast T1-weighted imaging techniques-standard three-dimensional gradient-echo (3-D-GRE), magnetization-prepared gradient-recall echo (MP-GRE) and 3-D-GRE with radial data sampling (radial 3-D-GRE)-acquired in pediatric patients younger than 5 years of age. MATERIALS AND METHODS: Sixty consecutive exams performed in 51 patients (23 females, 28 males; mean age 2.5 ± 1.4 years) constituted the final study population. Thirty-nine scans were performed at 3 T and 21 scans were performed at 1.5 T. Two different reviewers independently and blindly qualitatively evaluated all sequences to determine image quality and extent of artifacts. RESULTS: MP-GRE and radial 3-D-GRE sequences had the least respiratory motion (P < 0.0001). Standard 3-D-GRE sequences displayed the lowest average score ratings in hepatic and pancreatic edge definition, hepatic vessel clarity and overall image quality. Radial 3-D-GRE sequences showed the highest scores ratings in overall image quality. CONCLUSIONS: Our preliminary results support the preference of fat-suppressed radial 3-D-GRE as the best post-contrast T1-weighted imaging approach for patients under the age of 5 years, when dynamic imaging is not essential.

MR findings of lithium-related kidney disease: preliminary observations in four patients.

PURPOSE: To describe MR features of the kidney in patients on chronic lithium therapy and to correlate findings with the level of renal impairment. METHOD: In this retrospective HIPPA compliant study, a search was performed in our institutional clinical and radiological computerized database for subjects with lithium-related kidney disease between August 1, 2009 and May 30, 2010. Four patients (2 male and 2 females, mean age 64.75 ± 3.5) with a total of eight kidneys fulfilled the search criteria. T2-weighted images were used to evaluate the presence, size, and distribution of renal cysts. T1-weighted images were used to evaluate kidney length, parenchymal thickness, and cortico-medullary differentiation (CMD). RESULTS: All kidneys displayed multiple, very abundant, small size (1-2 mm) cysts. The distribution of the cysts was symmetric in renal cortex and medulla and the number of cysts was similar in both kidneys. Sparse, asymmetrical parenchymal renal cysts >3 mm in diameter were also observed. The size and parenchyma thickness of both kidneys was considered normal in all patients. The CMD differentiation was preserved only in patients with normal laboratory kidney findings (n = 2), but was lost in patients with chronic renal failure. CONCLUSIONS: Multi-microcystic kidney disease secondary to long-term lithium therapy can be detected with MR imaging regardless of known renal impairment. Preservation of renal CMD was observed in both patients with normal kidney function. The results of our preliminary study suggest the possible role of MR imaging for the screening of early manifestations of nephropathy in patients undergoing chronic lithium therapy.

Types of clinical studies. IV. Clinical trials.

Clinical practice should be based on the best available information from high-quality studies. Among the various study models, the randomized controlled trial, despite some disadvantages, is usually considered the gold standard for determining the efficacy of an intervention (drugs, surgery, etc.), and so this type of study should be part of all rational, conscious clinical decision-making. In this article, we present the classic structure of a randomized controlled trial, together with indications for critical appraisal of quality, as well as a brief discussion of the design, conduct and results, for correct determination of an intervention's effect.

Asymptomatic carotid bruit.

Cerebrovascular events are responsible for high morbidity and mortality, and carotid atherosclerosis with vascular stenosis is a major etiological factor in cerebrovascular disease. Carotid bruit is an important marker of generalized atherosclerosis. On the basis of good quality studies, we can conclude that it indicates an increased risk of cerebrovascular events and acute myocardial infarction, with the degree of carotid stenosis and presence of ischemic heart disease as the most important predictive factors. Management can be medical (risk factor modification and antiplatelet therapy) or surgical (endarterectomy). In this review article we briefly discuss the management of asymptomatic carotid bruit based on the main studies published in the last few years addressing cardiovascular event prevention in carotid atherosclerosis.

Hepatic sarcoidosis: MR appearances in patients with chronic liver disease.

PURPOSE: To describe the MR appearances of hepatic sarcoidosis in patients with chronic liver disease and correlate the results with clinical stage of disease as measured with the Mayo end-stage liver disease (MELD) score. MATERIALS AND METHODS: Twenty patients with chronic liver disease and histopathological diagnosis of hepatic sarcoidosis who underwent MR imaging were included in this study. Two abdominal radiologists retrospectively reviewed all images for the presence of cirrhosis, imaging pattern of the liver, intrahepatic biliary dilatation, presence of areas of parenchymal atrophy, presence of splenic nodules and lymphadenopathy. Imaging findings were correlated with the MELD score. RESULTS: Of the patients, 14/20 had imaging findings of cirrhosis, 9/20 had a large macronodular pattern of liver cirrhosis and 5/20 had a diffuse pattern of liver cirrhosis. Peripheral wedge-shaped areas of parenchymal atrophy were observed in 10 patients. The combination of a central macronodular pattern and peripheral atrophy was observed in 9/20 patients. The pattern of cirrhosis had statistically significant correlation with the presence of wedge-shaped areas of parenchymal atrophy (p<0.005). No statistically significant difference was revealed between the clinical score of patients who had imaging findings consistent with cirrhosis and those who did not. CONCLUSION: MR imaging appearances of chronic sarcoid liver disease are diverse and do not appear to correlate with severity of clinical disease. Large central regenerative nodules and wedge-shaped areas of peripheral parenchymal atrophy are frequent findings and may help to suggest the diagnosis.