In spinal fusion surgery, there are three big advantages to an intra-operative sliding gantry CT. First of all, the patient does not have to move during the surgery and can be operated on using a standard surgical table. The CT scanner simply slides on rails over the patient, providing imaging on demand. The CT scanner can then be moved out of the way when not in use, giving the surgeon full access to the surgical site. Secondly, the images that are required for the surgical navigation-aided stabilization procedure are generated in the patient’s final surgical position. This results in highly accurate images and therefore more precise surgical navigation and screw placement. The third advantage is that the position of the implants can be controlled immediately. Spine surgeons can see whether the screws or rods are compressing any structure and act without delay. This can spare the patient from complications and the potential for costly additional surgeries. With intra-operative CT, there are even workflow benefits: Thanks to the integration of the CT scanner with the neuronavigation system (for example, Brainlab), the coregistration procedure with CT images occurs automatically.
Patients who need spinal fusion surgery are not the only ones to benefit from intra-operative CT.
Neurosurgeons want to resect brain tumors and their margins as accurately as possible and prevent damage to the normal brain. But a neuronavigation system is only as reliable as the images that it draws on. During surgery, however many things can change. When resecting glioma tumors, the brain is known to shift. In meningioma patients, the surgical field changes as a result of the bone drilling that needs to be performed. Using intra-operative CT allows the dataset for the neuronavigation system to be updated whenever necessary. The result is that it becomes easier to preserve delicate structures – and at the same time, neurosurgeons can be more confident that they have removed the tumor and its margins as completely as possible.
Neurovascular surgeons can monitor the results of complex aneurysm-clipping surgeries with intra-operative CT: They find that CT angiography and CT perfusion scans can be helpful. CT angiography visualizes the site and shows whether or not the vessel patency has been preserved. With CT perfusion scans, neurovascular surgeons can view the distant perfusion in order to evaluate whether the clipping had a detrimental effect on other brain regions.
Compared to most mobile CT vendors, which primarily focus on visualizing bones (that is, the spine) in non-obese patients, the soft-tissue contrast offered on Siemens intra-operative CT systems is far superior, and enables the visualization of tumors and nerve structures in greater detail. Equally superb is their ability to perform CT angiograms, CT perfusion imaging, metal artifact reduction, Dual Energy capabilities, and iterative reconstruction methods to reduce dose. Siemens intra-operative CT is the modality of choice for those neuro and spine surgeons who need to see more than just bone in a wide variety of patients, from pediatric to obese.