Young women at risk of having a pulmonary embolism - a potential life-threatening blockage in a lung artery - should first undergo a ventilation/perfusion lung scan (V/Q scan) rather than a CT (computed tomography) angiogram, conclude authors in a paper published in the September Journal of Nuclear Medicine.
“A V/Q scan can be the first choice - but the CT angiogram is the classic choice - for diagnosing a pulmonary embolism,” noted H. Dirk Sostman, a professor of radiology and executive vice dean at Weill Cornell Medical College in New York City and chief academic officer at the Methodist Hospital in Houston, Texas. “A ‘very low probability' V/Q lung scan - together with a ‘low probability' objective clinical assessment - is as reliable as a CT angiogram and allows a doctor to evaluate whether a pulmonary embolism is present or not,” added Alexander Gottschalk, a professor of diagnostic radiology at Michigan State University in East Lansing.
A noninvasive V/Q scan involves two tests using radioactive material to measure breathing (ventilation) and circulation (perfusion) in all areas of the lungs, said Gottschalk, who has performed research with studies like the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) project for more than 30 years. V/Q scans reduce the radiation to the breast by about 70 times on average compared to higher-radiation procedures such as computed tomography pulmonary angiography (CTA), he explained.
“While CTA is the major test used widely to detect pulmonary embolisms, it is associated with higher radiation risk, especially for young women of reproductive age,” said Gottschalk. “The combination of a low probability V/Q scan and low probability clinical assessment is extremely effective,” said Sostman. “Our study is important for doctors—and their patients—since tests show that high radiation doses to the breast from CT, especially important in young women, may increase their risk of breast cancer,” he added.