MR/CT image fusion of the spine after spondylodesis: a feasibility study

Abstract

The objective of this study is to evaluate feasibility, accuracy and time requirements of MR/CT image fusion of the lumbar spine after spondylodesis. Sagittal MR and CT images derived from standard imaging protocols (sagittal T2-weighted MR/sagittal reformatted multi-planar-reformation of the CT) of the lumbar spine with correct (n = 5) and incorrect (n = 5) implant position were fused by two readers (R1, R2) using OsiriX in two sessions placing one (session 1) or two (session 2) reference point(s) on the dorsal tip(s) of the cranial and caudal endplates from the second lumbar to the first sacral vertebra. R1 was an experienced musculoskeletal radiologist; R2 a spine surgeon, both had received a short training on the software tool. Fusion times and fusion accuracy, defined as the largest deviation between MR and CT in the median sagittal plane on the ventral tip of the cranial end plate of the most cranial vertebra visible on the CT, were measured in both sessions. Correct or incorrect implant position was evaluated upon the fused images for all patients by an experienced senior staff musculoskeletal radiologist. Mean fusion time (session 1/session 2; in seconds) was 100.4/95 (R1) and 104.2/119.8 (R2). Mean fusion deviation (session 1/session 2; in mm) was 1.24/2.20 (R1) and 0.79/1.62 (R2). The correct/incorrect implant position was identified correctly in all cases. In conclusion, MR/CT image fusion of the spine with metallic implants is feasible, fast, accurate and easy to implement in daily routine work.

Accuracy and Reliability of Length Measurements on Three-Dimensional Computed Tomography Using Open-Source OsiriX Software

“…Recently, there has been a growing interest in 3D-CT as a research tool for the study of bone and joint anatomy and kinematics [1][2][3][4][5]. The resolution of CT is half the voxel size of CT scan [6,7].…”

Three-dimensional reconstruction of extremity tumor regions by CT and MRI image data fusion for subject-specific preoperative assessment and planning

“…The CT/MRI image fusion offers three key advantages: (1) fused 2D images to provide anatomical information on the bony and non-bony structures; (2) a practical tool for accurate localization of the target tumor for real-time intraoperative navigation; and 3) a useful tool for fusing CT-and MRI-based 3D models to recreate the complex 3D tumor region for preoperative assessment and planning. At present, the first two advantages are widely generalized with broad acceptance [4,[16][17][18]; however, too little emphasis has been placed on the third advantage.…”

Three-dimensional image fusion across PET+MRI modalities based on the approach of characteristic coregistration

“…Patients were in supine position with arms up from parietal bone to hip joint to capture axial images; sagittal and coronal images were acquired by multiplane reformation [7,11] .…”

“…X-ray computed tomography (CT) shows superior contrast to hard tissues [2] but inferior contrast to soft tissues than magnetic resonance imaging (MRI) does. Therefore, an image fusion is essential to obtain complementary information in the field of diagnostics and treatment [7] .…”