Spine’s Imaging Potential

Minimally invasive Techniques have raised the demand for capturing anatomical procedures
By Amir Vokshoor M.D. & Robert S. Bray Jr. M.D.
Outpatient Surgery Magazine – November, 2007  

Room for Improvement: A digital OR lets every member of the surgical
team follow the surgeon’s progress.

MULTIPLE APPLICATIONS C-arm imaging can also be used for pain management
cases and intra-articular injections in CT and MRI suites.

Quality imaging is essential to navigating the spine during surgery. The small margin of error that minimally invasive techniques allow has heightened the need for more refined images. A successful spine facility will need a quality C-arm, fluoroscopy unit and radiolucent surgical tables. Fluoroscopy provides surgeons with a 2-D image of the targeted area. Intraoperative CT scanning offers a 3-D picture of the patient's anatomy and is ideal for more complex spine cases.

Digital ORs, meanwhile, offer a glimpse into the not-so-distant future of spine imaging. The digital revolution is here to stay and high-tech ORs are becoming an integral part of facility makeovers. Consider the possibilities for spine procedures. Localization of intraoperative films is performed much faster and more precisely with digital-based computed radiography than by shooting images onto plain films.

ORs are completely integrated; data and images are feed directly into the room's computer system. Any member of the surgical team can track the surgeon's progress as information and images are transmitted seamlessly throughout the clinical area.

The OR tech and anesthesiologist each have their own high-resolution screen positioned on a boom system and can directly control which feed they watch. The circulating nurse controls the archiving of case information, inducting direct real-time printouts of CT images.

Information can be packaged for data archiving or transmitted within the surgical center or to a conference room at a remote site. Images can even be captured and set for Intenet transmission, a feature currently limited only by broadband capability. Computed radiography reviews and C-arm imaging can also be used after surgery for pain management cases and for intra-articular injections CT and MRI suites.

Every piece of equipment - the microscope, digital cameras, overhead lights, room overview cameras, C-arms, electrophysiology recording lights, sound system and, yes, the surgeon's iPod – are centrally controlled.

It's sometimes amazing that all this technology actually works. The build-out to accomplish the digital OR layout is involved and needs
to be planned both before and during construction of a new facility. Miles of cable and fiber optics need to be laid within the walls and a great deal of thought is required to ensure every monitor is placed for ideal viewing by each member of the surgical team. You also have to decide which information and images you want to capture and how you want to use them. But if the digital OR is well planned, it will maximize your patient flow and spine case efficiency.

Imaging Options More Than Just X-Ray  Note: Use Photo of MRI with Fish
By Rachel Gordon, MD, CAO

Imaging has become integral in the evaluation and follow-up of spine patients. Today, radiologists and surgeons are working together to ensure that the proper imaging studies are performed in a timely fashion. Often imaging centers will be constructed on-site or in close proximity to surgery centers to facilitate patient care. We image (MRI and CT) a wide variety of spine disease each day.

Disk herniation and spinal stenosis (narrowing of the spine) are the most common problems facing patients. Less-common diagnoses are synovial cysts of the facet joints and spinal tumors. Depending on the case, there are a handful of ways radiologists can capture detailed images of the spine. Most imaging is done before surgery to help with diagnosis and to provide the surgeon with an anatomical roadmap. Post-operative imaging is performed routinely to evaluate healing after surgery.

Occasionally patients are imaged to assess scar tissue, possible infection or abnormal fluid collections. Emergent postoperative imaging is usually performed if a patient complains of unexpected weakness or numbness in an extremity.

MRI will capture an image of any part of the spine. The image shows the para-spinal muscles, spinal cord, vertebrae and the disks. MRI is the first study done on spine patients and often defines the pathology without additional imaging. Some patients, especially those who have had prior spine surgery will also require MRI with a gadolinium-based contrast material. Gadolinium injection highlights abnormal tissues. This helps the radiologist and surgeon get a better look at postoperative scar tissue. Gadolinium can cause side effects such as mild nausea, although the incidence is rare.

Metal in the body, such as orthopedic hardware, always causes image distortion and blurring. In these cases, we routinely use a special metal artifact reduction sequence in order to obtain clear diagnostic images. Some patients may also require CT imaging. While MRI is exquisitely sensitive to soft tissues such as the disks and nerve roots, CT scans are better at defining the vertebral bodies and facet joints.

Not every patient is able to have an MRI. Those with pacemakers, implanted cardio-version devices such as defibrillators and certain other devices should not undergo MRI. Additionally, some patients are claustrophobic in MRI units. In these cases, we use a CT scan as an alternative. However, CT is the imaging study of choice in patients with suspected vertebral fractures or for evaluation of bone lesions. The radiologist performs a high-resolution imaging technique using sub-millimeter "cuts." This data is then used to create two- and three dimensional computer-generated models. These images are often used for surgical planning.

We perform a CT myelogram when we need to see the affected nerve in patients with a suspected herniated disk. The radiologist injects contrast material into the spinal canal under fluoroscopic guidance. The intrathecal contrast combined with the CT scan creates exquisite pictures of the nerve roots. Patients who've had a spinal fusion procedure undergo routine CT scanning to assess the progress of the fusion, which will heal and eventually become solid.