Pelvic Imaging for Venous Thromboembolism can be Restricted to Prevent Unnecessary Radiation Exposure

A recent study, conducted under Dr. Charbel Ishak, has concluded that pelvic imaging using computed tomography (CT) does not improve the chances of diagnosis of venous thromboembolism (VTE). This means that we can prevent unnecessary radiation exposure to patients undergoing CT venography by not including the pelvis during the procedure.

The study reviewed retrospectively, the history of 1,527 patients at the Nassau University Medical Center, for a period of three years. They found that only 0.3% of the patients, i.e. 5 of 1,527 patients developed isolated pelvic VTE after they underwent CT venography, which did not include the pelvic region.In view of this study, radiologists can develop new protocols for the diagnosis of venous thromboembolism. These protocols may exclude pelvic imaging while continuing with the established procedure of taking images from the groin to below the knee. Adopting this procedure will considerably reduce the amount of radiation to which the patients are exposed without making any significant change in the diagnosis of VTE.

Venous thromboembolism results in a large number of deaths every year. It is basically caused because of a hypercoagulable state resulting from vessel wall damage, venous stasis or in conditions where the clotting factors are over active. It is a common condition in critically ill patients where it may lead to serious complications. The condition is diagnosed on the basis of Wells criteria, detection of thrombus on CT venography, Doppler ultrasonic recording and electrical impedance plethysmography.

CT use has risen considerably in the recent years. Although its importance in the diagnosis of various diseases is undisputable, many patients undergoing CT of the abdomen or pelvis receive unnecessary image acquisition. Undue reliance on CT venography in suspected cases of VTE, wherein multiple serial images are acquired, results in increased exposure of the patient to radiation. This is unnecessary and avoidable at times. According to Dr. Ishak, the results of the new study will prompt radiologists to avoid pelvic imaging during CT venography of lower extremities, thereby reducing the amount of radiation to which their patients are exposed.

References:
• http://www.eurekalert.org/
• http://www.ncbi.nlm.nih.gov/pubmed/17446783
• http://www.physorg.com/