Techs need advanced postprocessing skills

February 1, 2007

Postprocessing software vendors sell their software based on the "push of a button" fantasy: Simply by pressing several buttons, the user completes the entire case. Although software interfaces are becoming increasingly more user-friendly, postprocessing volumetric data still requires an advanced skill set.

Postprocessing software vendors sell their software based on the "push of a button" fantasy: Simply by pressing several buttons, the user completes the entire case. Although software interfaces are becoming increasingly more user-friendly, postprocessing volumetric data still requires an advanced skill set. This need is indicated by the number of physicians seeking specialized training courses to process cardiac cases. Unfortunately, while doctors are receiving advanced education, technologists are being left by the wayside, with only limited vendor-specific applications training.

Although many physicians are learning how to use postprocessing software, it is increasingly apparent that this task will become the responsibility of technologists. More and more postprocessing labs are popping up around the country where dedicated technologists prepare postprocessed data sets for a physician's review. The technologists who work in these labs are typically those who have taken the initiative to learn the software through applications training and/or trial and error.

Many technologists still lack adequate knowledge of cross-sectional anatomy, however, or a basic understanding of the physical principles from which volumetric data are created. The push of a button myth creates an obstacle to obtaining this education by suggesting that the software alone can produce quality images, regardless of the user.

BUTTONS VERSUS BRAINS

Push-button features may work in optimal cases, but the variables of human anatomy and scan data frequently create challenges that the user must be able to manage. If technologists rely wholly on the button-pushing method, computer discrepancies may not be recognized.

Qualified technologists should be able to recognize anomalies in anatomy, but a sound understanding of normal anatomy is the prerequisite for this capability. Technologists should possess a basic understanding of the pathologies common to postprocessing cases and be prepared to visualize them. They should be able to recognize, for example, not only the obvious hard plaques in a vessel but also the soft plaque that appears as filling defects.

Technologists should have a thorough understanding of how volumetric data are created and also of their limitations. They should understand how data can be manipulated with windowing and segmentation to change the appearance of the volume and should be able to construct accurate curved planar reformats (CPRs) so that the centerline accurately follows the center of the lumen.

A poorly placed seed point along the length of the CPR may present the appearance of a false stenosis. If measurements are required, technologists should follow best practices to improve the consistency of each measurement and understand the limitations of accuracy based on spatial resolution.

The American Registry of Radiologic Technologists may eventually consider an advanced certification for technologists who perform postprocessing. When physicians rely on postprocessed images to make a diagnosis, a minimum standard of performance should be required. As 64-slice scanners enter into hospital use across the country, technologists cannot avoid the obvious change in workflow that postprocessing brings to the imaging department. Hospitals must be prepared to invest in educating technologists in advanced 3D and postprocessing skills to ensure the best quality of medical imaging.

Dr. Brown is academic program coordinator for the volumetric medical imaging program at Jefferson Community & Technical College in Louisville, KY.