AJR: Is imaging for PE inconsistent across U.S.?
Despite physician practices being broadly consistent with recommendations in the medical literature, there are variations by physician specialty and geographic location that may highlight evidence of inappropriate imaging in the diagnosis of pulmonary embolism (PE), according to a study published online in the April issue of the American Journal of Roentgenology.

The study, led by Mythreyi Bhargavan, MD, of the American College of Radiology (ACR) in Reston, Va., and colleagues analyzed Medicare patients with emergency department visits or inpatient stays with a diagnosis of PE or for symptoms related to PE.

According to the authors, imaging tests used in the diagnosis of this patient population can include CT angiography and ventilation-perfusion scintigraphy, as well as echocardiography, cardiac perfusion imaging and duplex ultrasound.

Bhargavan and colleagues retrospectively reviewed 5 percent of the Medicare research identifiable files for the selected patient-population and determined the number of patients who underwent each type of imaging test. Then, variations were evaluated in the first non-chest radiographic test by site of care and treating physician specialty. Variations in the use of common imaging tests were also studied and these findings were attributed to patient characteristics, physician specialty, site of care and geographic location.

The authors found that within the patient group in which PE was suspected, the most commonly performed tests were echocardiography (26 percent), CT or CT angiography of the chest (11 percent), cardiac perfusion study (6.9 percent) and duplex ultrasound (7.3 percent). However, individuals with an inpatient diagnosis of PE were found to have undergone chest CT or CT angiography (49 percent), duplex ultrasound (18 percent), echocardiography (10.9 percent) and ventilation–perfusion scintigraphy (10.9 percent) most commonly, they wrote.

“For patients for whom PE might have been suspected, many large variations were found in practice patterns among physician specialties and geographic locations,” said co-author Rebecca Lewis, MPH, from ACR. “There were fewer variations among patients with the inpatient diagnosis of PE and there are substantial differences in patterns of use of tests across geographic areas, probably reflecting differences in physician practice patterns,” she noted.

In addition, the authors found that many patients presenting with PE had not undergone any of the specific imaging tests recommended for the diagnosis of PE or for ruling out likely alternatives, which the authors wrote is true for at least one fourth of this patient-population.

“This finding is puzzling because PE is a serious disease and a broad range of imaging tests is available,” said the researchers.

The authors concluded that the results of their study correspond with findings in the literature, but could potentially vary for other patient-populations aside from Medicare patients in the hospital setting.