MRI guided percutaneous abdominal biopsy in a closed magnet: assessment in an animal study

MRI guided percutaneous abdominal biopsy was evaluated in an animal model, using a closed magnet and different types of needles. Thirty-six single pass biopsies were performed in 6 piglets with 6 types of MR compatible needles. Virtual targets of a diameter of 2 cm were drawn on the images of the right and left lobe of the liver and the upper and lower poles of both kidneys. FMPSPGR sequences were applied during an apnea of 19 to 23 seconds in axial, sagittal, coronal or axial oblique planes using a closed 1.0 T magnet and the body coil. Piglets were autopsied 1 hour after the procedure. Mean duration of the procedure was 16.9 (11-37) minutes; mean number of acquisitions per procedure was 5.9 (3-12); mean number of redirections of the needle was 0.6 (0-4). Pathological samples from the liver and kidneys of good quality were obtained in 22/36 (72.2%) cases. A subcapsular hematoma was observed in 18/24 (75.0%) cases of renal biopsies and in 1/12 (8.3%) of hepatic biopsies. No statistically significant correlation could be established between duration of the procedure and site of biopsy and between the type of biopsy needle and complication (p = 0.18 to 0.85). In conclusion, MRI guided percutaneous needle biopsy in the abdomen is a reliable technique in piglets using a closed magnet.