AJR. American journal of roentgenology
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AJR Am J Roentgenol · Jan 1994
Comparative StudyMR imaging of bone marrow lesions: relative conspicuousness on T1-weighted, fat-suppressed T2-weighted, and STIR images.
Fat-saturation pulse sequences offer important potential advantages for depiction of bone marrow lesions on MR images. The objectives of this study were to evaluate the relative conspicuousness of bone marrow lesions on images obtained by using two of the most widely available fat-suppression techniques, short-TI inversion recovery (STIR) and fat-saturation T2-weighted imaging, and to analyze the effect of these methods on image quality. In addition, we sought to determine if either or both of these sequences provide significant advantages relative to conventional T1-weighted spin-echo images for the evaluation of bone marrow lesions. ⋯ T1-weighted, fat-saturation T2-weighted, and STIR sequences all provide a high degree of sensitivity for depiction of most types of bone marrow abnormalities. Although the conspicuousness of lesions is similar on fat-saturation T2-weighted and STIR images, the former sequence has several practical advantages, including acquisition of more slices per unit time and improved tissue specificity. The combination of T1-weighted and either fat-saturation T2-weighted or STIR images is highly effective for the evaluation of bone marrow lesions.
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AJR Am J Roentgenol · Jan 1994
Aspergillosis of the brain and paranasal sinuses in immunocompromised patients: CT and MR imaging findings.
With the increased survival of patients with severe immunosuppression, it has become more important to recognize the various forms of cerebral and craniofacial aspergillosis. Currently, only small series of patients with this infection have been described; the radiographic diagnosis of cerebral and craniofacial aspergillosis has varied and has been relatively nonspecific. The purpose of our study was to identify neuroimaging patterns in patients with cerebral and craniofacial aspergillosis. Recognition of radiographic patterns of aspergillosis may facilitate earlier radiologic diagnosis and prompt therapy. ⋯ Three different neuroimaging patterns of cerebral aspergillosis were identified in immunosuppressed patients. The first pattern was multiple areas of hypodensity on CT scans or hyperintensity on T2-weighted MR images involving the cortex and/or subcortical white matter consistent with multiple areas of embolic infarction. This pattern could be seen with or without superimposed hemorrhage, identified as hyperdensity on CT scans or as hyperintensity on T1-weighted MR images. The second pattern was multiple intracerebral ring-enhancing lesions consistent with abscesses. The ring was irregular and of low signal on T2-weighted MR images. The third pattern was dural enhancement associated with enhancing lesions in the adjacent paranasal sinus structure or calvaria or dural enhancement of the optic sheath with associated optic nerve and intraorbital fat enhancement. Recognition of these three patterns of aspergillosis in immunosuppressed patients may lead to more effective diagnosis and treatment planning.
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AJR Am J Roentgenol · Jan 1994
Fluid in normal and abnormal ankle joints: amount and distribution as seen on MR images.
The appearance of fluid in tendon sheaths of the ankle joint and in ankle articulations seems to vary. To determine the degree of this variability and to see if fluid occurs in normal ankles, we evaluated the presence, amount, and distribution of joint fluid as seen on MR images of normal and abnormal ankles. ⋯ Our results show that fluid in the articulations and tendon sheaths of the ankle is common in asymptomatic patients, and the amounts of fluid are not significantly different from the amounts in patients with symptoms. There also appear to be complex interrelationships between fluid seen in the joint and in tendon sheaths.