Imaging and intervention of retroperitoneal fibrosis.

Retroperitoneal fibrosis is a rare condition characterized by the development of fibrous plaques in the retroperitoneal space. The fibrous plaques characteristically arise distal to the bifurcation of the abdominal aorta and progress to encase the iliac vessels distally and are defined by the associated encasement of one or both ureters. Imaging plays an important role in not only establishing the diagnosis, but also in monitoring disease progression. Historically, the radiological diagnosis was made predominantly by intravenous urography and retrograde pyelography. More recently, advances in cross-sectional imaging with ultrasound and contrast-enhanced CT have allowed for a more precise diagnosis as well as helping to accurately define the extent of the disease. At our institution, we have found ultra-fast MRI to also play a useful role in establishing the diagnosis. In particular, magnetic resonance urography using HASTE (half Fourier-acquired single shot turbo spin-echo) sequences allow a safe alternative to intravenous urography, particularly in patients with poor renal function. The purpose of this article is to describe the role of the various imaging methods available to the radiologist and to emphasize the important role that the interventional radiologist now plays, not only in obtaining tissue for diagnosis, but also in providing treatment of the disease by percutaneous nephrostomy drainage and subsequent stent placement in select cases.

CT-guided bone biopsy: Initial experience with a commercially available hand held Black and Decker drill.

PURPOSE: To describe the use of a simple commercially available Black and Decker hand based drill in performing CT-guided bone biopsies. MATERIALS AND METHODS: Three international institutions were enrolled in the study. In each centre, a fellowship trained musculoskeletal radiologist directed the assessment of a hand based commercial drill for performing CT-guided bone biopsies. A specially designed component was engineered which allowed the connection of a standard bone biopsy set to a commercial drill. The component was distributed to the three centres involved. Over a 3-year period, data from all three institutions was collected. Information regarding technical success, diagnostic data and complication rates were all collated to assess the technical feasibility of this technique. RESULTS: In total 68 patients underwent bone biopsy using a hand held commercial drill. Technical success was achieved in 65 patients. Diagnostic material was obtained in 53 patients. Non-diagnostic material was obtained in 12 patients. Five out of the 12 patients with non-diagnostic material had repeat biopsies with diagnostic material obtained in 2 of these. No major complications occurred in any patient. CONCLUSION: CT-guided bone biopsy using a hand held commercial drill has a technically high success rate with minimal complications.

Direct thrombin injection into aneurysmal sac in a patient with a type II endoleak.

Endovascular grafting of abdominal aortic aneurysms provides a good alternative to open surgery, especially in high-risk patients. Endoleaks are a well-recognized complication and are typically diagnosed on CT. We describe a case in which a patient's endoleak was evaluated by MRI and successfully treated by direct thrombin injection into the site of the leak.