Routinely reformatting computed tomography (CT) scans to view organs from several different directions may help radiologists improve diagnosis

May 17 2005

Routinely reformatting computed tomography (CT) scans to view organs from several different directions may help radiologists improve diagnosis, according to new research from Wake Forest University Baptist Medical Center. The results are being presented this week at the American Roentgen Ray Society meeting in New Orleans, La.

"You can see things in one view that you might miss in another," said Craig Barnes, M.D., section head of pediatric radiology at Wake Forest Baptist's Brenner Children's Hospital. "It costs no more as relates to scan time or radiation exposure, and we believe it provides added value in diagnosis."

CT scans use X-rays, radiation detectors and computers to produce images or "slices" through the body. In most cases, the images are in the axial plane – a view looking down through the body. But new faster multidetector CT scanners that can capture eight or more slices at once opened the door to alternate views. With proper processing, these other views are of similar quality to the original axial images.

In some cases, physicians reformat the data to view an organ from the front. Called the coronal plane, this is similar to the way an X-ray looks. Another view, the sagittal plane, provides a view from the side.

"These alternate views are sometimes used to make it easier to see organs such as the spleen and liver, or vascular structures such as the aorta," said Barnes. "We wanted to see if there was an advantage to using the alternate views on a routine basis."

For the past two years, Wake Forest Baptist has used all three views on abdominal and chest CT scans of pediatric patients. For their prospective study, they reviewed 44 chest CT scans and 40 abdominal CT scans and compared reading time and accuracy of the views.

Images in the sagittal and coronal planes, which present views that are similar to a physical exam, could be read more quickly because fewer images are required, Barnes said. Coronal images required an average of 54 images per patient, compared to 90 for axial images.

"Time efficiency was improved and diagnostic accuracy was maintained," said Barnes. "As radiologists become more familiar with reading in the alternate views, this approach may prove beneficial as a replacement, or in addition to, axial images."

He said that when used together, multiple planes can increase diagnostic accuracy. For example, the multiple views allowed the physicians to diagnose a metastatic tumor that might otherwise be confused with part of the primary kidney tumor.

"In the traditional axial view, the tumor looked like it was arising from the kidney, but using the three views, we saw it was actually involving the adrenal gland," he said. "The multiple views increase our confidence in diagnosis as well as accuracy."

Wake Forest Baptist is one of a few centers in the country routinely viewing pediatric CT scans in all three planes.

Barnes's co-researchers are Evelyn Anthony, M.D., Michael Chen, M.D., Louise Milner, M.D., and Susan Lie-Nelson, M.D., all from Wake Forest Baptist.