Update on imaging of non-infectious musculoskeletal complications of HIV infection.

Acquired immunodeficiency syndrome (AIDS) results from infection with human immunodeficiency virus (HIV), producing an immunodeficient state and severe pathology across multiple organ systems. Musculoskeletal involvement is particularly prevalent in this population with both infectious and non-infectious complications encountered, but it is suggested that the latter will affect 72% of HIV-infected individuals. In this review we aim to provide an update on the imaging characteristics of the non-infectious manifestations. The conditions include HIV-related arthritis as well as various malignancies, myositis, anaemia, osteonecrosis, rhabdomyolysis, hypertrophic osteoarthropathy and therapy-related side effects. For the clinician, the diagnostic challenge lies in differentiating disease-related symptoms from therapy-related side effects, particularly when clinical and laboratory features can be non-specific. This is especially difficult following the widespread introduction of highly active anti-retroviral therapy (HAART). Imaging investigations and MRI in particular have proven vital for facilitating early diagnosis and enabling prompt treatment. Furthermore, wider availability of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has allowed whole-body assessment for staging and treatment response of malignancy. Understanding the pathogenesis of the various conditions and recognising their imaging features is essential for the clinical radiologist.

Imaging of thoracic aortic disease.

Aortic pathology can be more complex to understand on imaging than is initially appreciated. There are a number of imaging modalities that provide excellent assessment of aortic pathology and enable the accurate monitoring of disease. This review discusses the imaging of the most common disease processes that affect the aorta in adults, with the primary focus being on CT and MRI.

Case report: MR imaging features of endometriosis at the umbilicus.

The radiological features of extrapelvic endometriosis at the umbilicus with large ovarian endometriomas are described. In this patient, the umbilical lesion appears as hypointense on T(1) weighted and T(2) weighted MR images. The MR characteristics of endometriosis at the umbilicus are compared with those found within the pelvis.

Osteonecrosis of the knee in a patient receiving antiretroviral therapy.

A case of avascular osteonecrosis of the right knee is described in a patient with HIV infection. The patient had been receiving highly active antiretroviral therapy for two years prior to presentation. Osteonecrosis is an uncommon albeit serious complication of HIV infection and is associated with use of antiretroviral agents.

Scrotal sonography: a valuable tool in the evaluation of complications following inguinal hernia repair.

PURPOSE: The aim of this study was to determine the utility of scrotal sonography in the evaluation of patients with scrotal pain or swelling following inguinal hernia repair. METHODS: From our database, we identified patients who were referred for sonographic evaluation because of persistent scrotal pain or swelling after inguinal hernia repair between July 1994 and February 1996. Sonograms and medical charts were reviewed retrospectively. RESULTS: Eight patients were included in this study. Doppler sonography demonstrated evidence of testicular infarction in 2 patients and absence of intratesticular diastolic flow in 1 patient. Five patients had postoperative fluid collections with sonographically normal testes. CONCLUSIONS: Scrotal sonography can diagnose testicular infarction following hernia repair and distinguish postoperative fluid collections from recurrent hernias.

The significance of paracardiac lymph node enlargement in ovarian cancer.

The computed tomography (CT) scans of 78 patients with stage II, stage III and relapsed stage I ovarian carcinoma were reviewed in order to identify the incidence of enlarged paracardiac lymph nodes in this disease, recognize their association, if any, with peritoneal metastases and establish whether they had any bearing on progression free interval and survival. Twenty-two patients (28%) were found to have enlarged paracardiac nodes, nine at initial presentation and a further 13 during the course of follow-up. The association between paracardiac node enlargement and peritoneal metastases was found to be highly significant. Thirty per cent of 27 patients with peritoneal metastases at presentation were found to have enlarged paracardiac nodes whereas of the 51 patients without peritoneal dissemination only 2% had enlarged paracardiac nodes (P < 0.001). In order to determine whether paracardiac nodal status had any independent prognostic value, multivariate analysis using Cox's regression was performed. When status at presentation was considered, the presence of enlarged paracardiac lymph nodes was found to be an independent predictor for survival. (Hazard ratio 3.70, 95% confidence interval (1.18-11.6), P < 0.04.) The hazard ratio for paracardiac nodal status with respect to progression free survival was not significant but in the expected direction. (Hazard ratio 1.85 (0.65-5.25).) When time-dependent covariate analysis was applied, paracardiac nodal status and peritoneal metastases status were found to be independent predictors for both progression free survival and overall survival. The presence of peritoneal metastases indicated a poorer prognosis than the presence of paracardiac lymph nodes, the hazards ratios for progression free survival were 12.9 and 2.58, respectively, and those for survival were 20.7 and 3.62, respectively. We have demonstrated that the presence of paracardiac lymph node enlargement is a significant adverse prognostic factor for both progression free interval and survival. The diagnosis of involved paracardiac lymph nodes is important as it can define patients having stage IV as opposed to stage III disease.

Ultrasound diagnosis of metastatic melanoma of the gallbladder.

The abdominal ultrasound examinations of 464 patients with malignant melanoma performed over a 3 year period were reviewed. 23 (5.2%) had soft tissue material attached to the gallbladder wall and projecting into the lumen. Four of these were polyps of less than 1 cm which were thought to be benign, while the remaining 19 had abnormalities likely to be metastatic melanoma. Upper abdominal ultrasound examinations are frequently requested for staging purposes in patients with thick high grade malignant melanoma or clinical suspicion of metastases. Ultrasound clearly identifies the gallbladder and biliary tree in the vast majority of patients and is generally regarded as the imaging modality of choice for suspected gallbladder pathology. As autopsy studies have confirmed the incidence of gallbladder metastases from malignant melanoma to be 15-20%, a careful review of the gallbladder is advocated when abdominal ultrasound examinations are performed on patients with malignant melanoma.