New CT scanner offers broadest range of capabilities

UC Davis CT services accredited by American College of Radiology

new CT scanner in use
CT Supervisor Bernabe Balala prepares to use the radiology department's new outpatient CT scanner.

The UC Davis Department of Radiology has installed a state-of-the-art CT scanner that offers the broadest range of scanning capabilities now available for outpatients. In a related development, the health system's CT services recently were accredited by the American College of Radiology.

Last month, the department scanned its first patient on the Siemens Definition AS Plus. UC Davis Health System is only the second location in California to have this scanner, and is the first academic medical center in the state to have it.

"With this new scanner, we have the technology here that is second to none," said Ramit Lamba, an assistant professor of radiology and the department's director of CT. "This is a huge step for our outpatient scanning, and we have the scanner capacity at UC Davis to allow scanning of all our patients without delay."

The scanner, located in the Ellison Building at UC Davis Medical Center in Sacramento, replaces a 10-year-old, G.E. four-detector scanner. The new scanner represents a vast improvement in capabilities, speed and safety, said Lamba.

"We now offer state-of-the-art CT scanning, with all scanners having accreditation from the American College of Radiology," Lamba said.

A measure of quality

The purpose of the American College of Radiology's CT accreditation program is to set quality standards for radiological practices and help them continuously improve upon the care they provide to patients. The accreditation program evaluates qualifications of personnel, equipment performance, effectiveness of quality-control measures and quality of clinical images.

Specifically, the accreditation program provides a peer-reviewed, educationally focused evaluation, may document a need for dedicated equipment, continuing education or qualified personnel, and expertly assesses image quality.

Faster scans, wider capabilities

In CT scanning, numerous X-ray beams and a set of electronic X-ray detectors rotate around a patient while the examination table moves through the scanner, so that the X-ray beam follows a spiral path. A computer processes this data to produce multiple two-dimensional, cross-sectional images of the body, known as slices.

"We now offer state-of-the-art CT scanning, with all scanners having accreditation from the American College of Radiology." 
— Ramit Lamba, assistant professor of radiology

The new CT scanner creates 128 slices in half a second, compared to the previous scanner, which could produce only four slices. And, whereas the previous scanner required four to five minutes to produce a complete reconstruction of CT slices on an abdominal CT, the new scanner can complete the process in less than 15 seconds.

The improved capabilities of the new scanner allow images to be viewed in all three anatomical planes: axial, coronal and sagittal.

The Definition AS also makes CT scanning available to a wider range of patients, thanks to a high-capacity, 650-pound patient table. The old scanner's table had a maximum weight limit of 400 pounds.

"For patients who were heavier than that, we could not use CT," said Lamba. "They were denied imaging. This was a huge disadvantage for them and their physicians. It limited health care for these patients."

The new scanner is equipped with a shield to protect patients from unnecessary radiation exposure. The shield physically blocks the x-ray beam from reaching tissue outside the region of interest.

The Definition AS also offers a wider range of applications in CT imaging. It can provide a variety of diagnostic information in patients suspected of having stroke or cardiac disease. It is capable of producing perfusion images of entire organs, including the brain, liver or kidney, which opens avenues for many new areas of research, said Lamba.