Imaging for spinal surgery. (2006)

Spine surgery has evolved into a specialty heavily dependent on high-quality diagnostic imaging. In Canada, patients and spinal surgeons alike continue to enjoy generally high standards of imaging quality. Whereas printed photographic film has been the traditional medium of image reproduction, current technology allows us to directly view digital images on standard computer displays, albeit often without the image quality required for diagnostic purposes. This approach, called the Picture Archive Communication System (or PACS), is the system that will eventually be used throughout North America. It offers the potential for large cost savings over printed films as well as increased versatility in image viewing.1 Given the noxious nature of photographic chemicals, the positive environmental impact is also important. Recognizing these advantages, it is not surprising that many medical imaging departments actively promote a conversion to the digital format. It is the consensus of the members of the Canadian Spine Society that the end users of this technology, the Canadian spine surgeons who rely on the technology to make final diagnostic and treatment decisions, have not been properly consulted before its implementation.

As long as the quality of the computer image is adequate, viewing computed tomography, magnetic resonance imaging, angiography, fluoroscopy and plain x-ray films are effective and efficient for diagnostic purposes. Viewing from remote PACS review stations throughout a region allows immediate consultation with other specialists. As technology improves, the reliability of this system is approaching and even surpassing that of the traditional system of film filing, which becomes increasingly expensive and unreliable as patient volumes increase.2

From a treatment perspective, the potential advantages of digital image viewing in spinal surgery are encouraging. In general, spinal surgeons have embraced new technologies in spinal surgery with cautious but welcoming attitudes. Computerized image handling is no exception.

Currently, the process of change is slow and initially expensive. Problems exist. Examining digital images requires computer hardware and compatible software. Viewing conventional photographic films of imaging studies requires only a view box or a window. It is not uncommon for spine surgeons to treat patients whose diagnostic studies have come from various different formats from other facilities or regions. As a result, lacking the simplicity of the photographic pictures, difficulties have been encountered in accessing critically important digital images. As compact discs replace film, the inability to open digital images in the office or, more crucially, in the operating room substantially impedes patient care. A failure to obtain the necessary pictures may require repeat studies: an unwarranted cost to the health care system and an unnecessary burden and possible risk to patients. Further, the quality of the available images is now dependent on the amount of data stored and on the resolution of the monitor, adding further potential sources of error. Most of the software programs for viewing these images (eFilm Lite, imageviewer) are specifically labelled as “not for diagnostic purposes.” The quality of the image reproduction is inadequate to make diagnostic and therapeutic decisions.3 This raises both quality of care and medical–legal issues. The spine surgeon viewing these pictures in the office, emergency department or operating room must make a clinical decision at that time. This decision can only be made with confidence if appropriate hardware and software are readily available.

Direct access to the PACS system can be sporadic and unacceptably time-consuming. Some modern facilities provide PACS stations in the examining rooms for rapid image access, but many others do not. When the consultation takes place in an off-site location, the acquisition time may far exceed the time needed to view plain films. A basic concern is the available line speed. The delay can be even further prolonged when the request includes archived studies that must be located and reloaded on the active server. In some cases, the firewall at the transmission site may prevent access altogether.4 Where the required equipment is unavailable or cannot function properly, having conventional films or a compatible compact disc remains essential. The same inconsistent availability of the PACS system is found in operating rooms across Canada, with potentially catastrophic consequences. PACS systems are designed to log off after a period of inactivity. Images may disappear during lengthy surgeries, requiring the surgeon to move to the computer terminal (delegation of this task is extremely difficult) to re-establish the link and relocate the pictures. When various images from multiple modalities are required simultaneously during surgery, the present systems are uniformly inadequate. For procedures requiring precise visualization, such as needle localization, the pictures in the operating room may be significantly and relevantly degraded from the images available to the radiologist, creating an additional threat to patient safety.

Spinal surgeons unanimously believe that the standard of care requires that appropriate images of a patient undergoing spinal surgery be displayed in the operating theatre. Although computerized image viewing through the PACS system is likely to become universally accepted in health care in Canada, this will take several years. While radiology departments enjoy the cost savings of conversion to digital film processing and storage, they should be cognizant of the unacceptable cost of medical errors that may result from inadequate access to imaging studies. The intermediate phase poses significant risks.