Technical Feasibility of Electromagnetic US/CT Fusion Imaging and Virtual Navigation in the Guidance of Spine Biopsies

Purpose To test the technical feasibility of electromagnetic computed tomography (CT) + ultrasound fusion (US)-guided bone biopsy of spinal lesions. Materials and Methods This retrospective study included 14 patients referred for biopsy of spinal bone lesions without cortical disruption or intervertebral disc infection. Lesions were located in the sacrum (n=4), lumbar vertebral body (n=7) or intervertebral disc (n=3). Fusion technology matched a pre-procedure CT scan with real-time ultrasound. The first six procedures were performed under both standard CT and CT+US fusion guidance (group 1). In the last eight procedures, the needle was positioned under fusion imaging guidance alone, and CT was only used at the end of needle placement to confirm correct positioning (group 2). Additionally, we retrieved 8 patients (controls) with location-matched lesions as group 2, which were biopsied in the past with the standard CT-guided technique. The procedure duration and number of CT passes were recorded. Results Mean procedure duration and median CT pass number were significantly higher in group 1 vs. group 2 (45±5 vs. 26±3 minutes, p=0.002 and 7; 5.25-8.75 vs. 3; 3-3.25, p=0.001). In controls, the mean procedure duration was 47±4 minutes (p=0.001 vs. group 2; p=0.696 vs. group 1) and the number of CT passes was 6.5 (5-8) (p=0.001 vs. group 2; p=0.427 vs. group 1). No complications occurred and all specimens were adequate overall. In one case in group 2, the needle position was modified according to CT assessment before specimen withdrawal. Conclusion Electromagnetic CT+US fusion-guided bone biopsy of spinal lesions is feasible and safe. Compared to conventional CT guidance, it may reduce procedural time and the number of CT passes.