The use of educational intervention can affect emergency department physician decisions on whether to use ventilation–perfusion (V/Q) scanning rather than CT pulmonary angiography (CTPA) for patients presenting with suspected pulmonary embolism (PE), according to a study in the February issue of the American Journal of Roentgenology."The purpose of our study was to decrease radiation exposure to emergency department patients with suspected PE, for whom imaging was clinically warranted, by safely increasing the use of V/Q scanning and decreasing the use of CTPA through an educational intervention," said Linda Haramati, MD, of the Montefiore Medical Center in New York City and lead author of the study.
Between December 2006 and January 2007, the radiology, nuclear medicine and emergency medicine departments at Montefiore held collaborative educational seminars on the subject of accuracies of V/Q scanning and CTPA for diagnosing PE, as well as radiation dose.
In an attempt to reduce radiation exposure for patients, an imaging algorithm was introduced in which emergency department patients with a clinical suspicion of PE underwent chest radiography. V/Q scanning was recommended in the case of the chest radiograph returning normal results, otherwise, CTPA was recommended.
The researchers kept track of the number, as well as the results of CTPA and V/Q scanning, and determined the average effective radiation dose before and after the educational sessions were held.
"The total effective radiation dose from CTPA is approximately five times greater than that from V/Q scanning, and the dose is 20 – 40 times greater to the female breast," said Haramati, noting that many physicians have not been made aware of these differences.
Based on the educational seminars, the authors wrote that the number of V/Q scans increased from 745 in 2006 to 1,216 in 2007. Similarly, the number of CTPA exams performed decreased from 1,234 in 2006 down to 920 in 2007.
Additionally, the average effective dose for each patient was reduced by 20 percent (from 8 mSv in 2006 to 6.4 mSv in 2007). The researchers also noted that the patients who underwent CTPA and V/Q scanning in 2006 were of similar age, and in 2007, the patients who underwent V/Q scanning were found to be “significantly younger.”
"We have shown that a simple, collaborative educational intervention and routing of patients to CTPA or V/Q scanning based on the results of chest radiography can change the practice pattern in the emergency department for patients with suspected PE,” concluded Haramati and colleagues. “The use of V/Q scanning in patients with normal chest radiographs results in considerably lower patient radiation exposure.”