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HWN Suggests

Don't Bury the V/Q Scan: It's as Good as Multidetector CT Angiograms with a Lot Less Radiation Exposure

The enormous increase in the number of MDCTAs for studying possible pulmonary embolic disease is a trend that must be reversed. This is necessary not only because of unacceptably high radiation exposure—particularly to the breasts of young women—but also because of the erroneous belief that it is a superior diagnostic tool as compared with V/Q imaging. In many instances, the considerably lower-radiation-exposure dose associated with the radionuclide study makes it a preferable choice.

It is the responsibility of the imaging physician to be knowledgeable about the relative value and the benefit-to-risk ratio of each procedure to properly advise the referring physician. Paramount to…

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Articles of Interest

CT Scan May Be Too Good at Finding Lung Problems, Study Finds

Until the introduction of CT angiography in 1998, the primary test for pulmonary embolism was ventilation/perfusion scanning, in which inhaled or injected radioisotopes are used to create an image of air and blood flow in the lungs. The small amount of radiation involved little risk for most people. But when CT angiography was introduced, doctors enthusiastically adopted it. It is now widely used instead of ventilation/perfusion and often employed to find the causes of various other lung disorders.

Diagnosing PE — Is V/Q Imaging a Better Choice, Especially for Younger Women?

We have found that using the chest x-ray as triage, the number of CTs we perform for diagnosis of PE is coming down while the number of V/Q scans is coming up, and the benefit to the patients is that they’re not unnecessarily exposed to excessive radiation...

V/Q Scan: The Preferred and Recommended Screening Test for CTEPH

V/Q scan is the preferred and recommended screening test for chronic thromboembolic disease in patients with PH. CTPA [computed tomography pulmonary angiogram] for screening may lead to potential misdiagnosis of PAH and underdiagnosis of CTEPH, including patients with distal disease.

What is a V/Q scan?

V/Q: The Right Treatment for the Right Patient at the Right Time. Compared with CTPA, the breast radiation dose from V/Q is approximately 40 times less in women and 90 times less in pregnant women.2 That’s why the American Thoracic Society recommends V/Q over CTPA in pregnant patients with a normal chest X-ray.

Resources

InsideRadiology

A VQ scan is carried out in two parts. In the first part, radioactive material is breathed in and pictures or images are taken to look at the airflow in the lungs. In the second part, a different radioactive material is injected into a vein in the arm, and more images taken to see the blood flow in the lungs.

MedlinePlus

This test has largely been replaced by CT pulmonary angiography for diagnosing pulmonary embolism. However, people with kidney problems or an allergy to contrast dye can more safely have this test.