Working group develops standard reporting system for CT colonography

Taking a cue from breast imaging, an international working group has developed a standardized reporting system for CT colonography. The step could help it win wider acceptance as a screening strategy for colon cancer.

Dubbed C-RADS (colonography reporting and data system), the system can be used to help describe findings on CT colonography scans both within and outside the colon. It is akin to the BI-RADS assessment commonly used in mammography.

"The growth of CT colonography requires the radiological community to organize performance and reporting," said Dr. Michael Zalis, an assistant radiologist in abdominal imaging and intervention at Massachusetts General Hospital.

Zalis presented the preliminary results of the Working Group on Virtual Colonoscopy Thursday at the Fifth International Symposium on Virtual Colonoscopy in Boston.

The C-RADS approach was designed to standardize reporting and does not cover how to perform virtual colonoscopies or how to read exams, according to Zalis.

The preliminary report passed out at the conference features tables covering:

• feature descriptions of polyps

• classification and suggested follow-up

• classification of extracolonic findings

Zalis said that common terms developed in the system could be extremely valuable for providing consistency to studies reported from a variety of sites.

The development of such a system could have far-reaching effects on organizations that are currently withholding recommendation of the procedure.

"The American Cancer Society has kept a very close eye on virtual colonoscopy," said Dr. Durado Brooks, director of prostate and colorectal programs at the society.

Although CT colonography is a promising modality, there is still considerable variation in technique.

"One of the basic tenets for a screening test is that it provide consistent and reliable results. The report on C-RADS is very encouraging," Brooks said.

The working group, which coordinated its efforts with the American College of Radiology Colon Cancer Committee, consists of experts who have published in the field of virtual colonoscopy or participated in an earlier International Symposium as faculty.

The group first began developing the reporting system at last year's symposium, after which members communicated during a series of comment gathering sessions. The group participated in four teleconferences and numerous e-mail communications before finally reaching a consensus on the major points of interpretation that were presented Thursday at the symposium.

The next step is publishing the report, Zalis said.

For more information from the online Diagnostic Imaging archives:

Obstacles to virtual colonoscopy fall quickly

Mammography: Audits measure practice quality of mammography

BI-RADS training promotes agreement between breast imagers

Duke study renews challenge of CT colonography