Susanne C. Göhde

Virtual MR angioscopy of the pulmonary artery tree

An optimized, contrast-enhanced 3D MR angiography sequence is combined with image postprocessing to render interior views of the pulmonary arteries. Virtual angioscopy was successfully demonstrated on both a healthy volunteer and a pulmonary embolism patient. By targeting selected pulmonary artery branches, virtual angioscopy has the potential to become a powerful adjunct to the use of reformatted sections and maximum intensity projections in the assessment of pulmonary embolism.

MR-guided cholecystostomy : Assessment of biplanar, real-time needle tracking in three pigs

PurposeTo demonstrate the feasibility of magnetic resonance (MR)-guided cholecystostomy using active, real-time, biplanar MR tracking in animal experiments.MethodsExperiments were performed on three fully anesthetized pigs in an interventional MR system (GE open). The gallbladder was displayed in two orthogonal planes using a heavily T2-weighted fast spin-echo sequence. These “cholangio roadmaps” were displayed on LCD monitors positioned in front of the interventionalist. A special coaxial MR-tracking needle, equipped with a small receive-only coil at its tip, was inserted percutaneously into the gallbladder under continuous, biplanar MR guidance. The MR-tracking sequence allowed sampling of the coil (needle tip) position every 120 msec. The position of the coil was projected onto the two orthogonal “cholangio roadmap” images.ResultsSuccessful insertion of the needle was confirmed by aspiration of bile from the gallbladder. The process of aspiration and subsequent instillation of Gd-DTPA into the gallbladder was documented with fast gradient-recalled echo imaging.ConclusionBiplanar, active, real-time MR tracking in combination with “cholangio roadmaps” allows for cholecystostomies in an interventional MRI environment.