Use of preoperative 3D CT/MR fusion images and intraoperative CT to detect lesions that spread onto the brain surface.

OBJECTIVE: Preoperative 3D CT/MR fusion images were prepared for preoperative evaluations and intraoperative assistance for the following lesions: arteriovenous -malformations (AVMs), meningiomas, and metastatic tumors that spread onto the brain surface. METHOD: We prepared 3D CT/MR fusion images for 4 AVMs, 13 meningiomas, and 7 metastatic tumors, and demonstrate representative cases. Data acquired from 16-slice multidetector CT and 1.5-T MRI were used. The volume rendering technique was used. During operations, mobile 16-slice multidetector CT was used to update information. RESULTS: Even after opening the dura mater, the relationship between a brain surface lesion and the surrounding structures on the preoperative 3D fusion images corresponded to the patient's operation field. Updated information via intraoperative CT was useful because operation fields might change owing to the brain shift. These images made extirpations of lesions easier and less invasive. CONCLUSION: Not only the preoperative 3D information, but also intraoperative CT information are beneficial for smooth and safe operations.

3-D MRI/CT fusion imaging of the lumbar spine.

OBJECTIVE: The objective was to demonstrate the feasibility of MRI/CT fusion in demonstrating lumbar nerve root compromise. MATERIALS AND METHODS: We combined 3-dimensional (3-D) computed tomography (CT) imaging of bone with 3-D magnetic resonance imaging (MRI) of neural architecture (cauda equina and nerve roots) for two patients using VirtualPlace software. RESULTS: Although the pathological condition of nerve roots could not be assessed using MRI, myelography or CT myelography, 3-D MRI/CT fusion imaging enabled unambiguous, 3-D confirmation of the pathological state and courses of nerve roots, both inside and outside the foraminal arch, as well as thickening of the ligamentum flavum and the locations, forms and numbers of dorsal root ganglia. Positional relationships between intervertebral discs or bony spurs and nerve roots could also be depicted. CONCLUSION: Use of 3-D MRI/CT fusion imaging for the lumbar vertebral region successfully revealed the relationship between bone construction (bones, intervertebral joints, and intervertebral disks) and neural architecture (cauda equina and nerve roots) on a single film, three-dimensionally and in color. Such images may be useful in elucidating complex neurological conditions such as degenerative lumbar scoliosis(DLS), as well as in diagnosis and the planning of minimally invasive surgery.