Pulmonary embolism in pregnancy: is nuclear medicine imaging still a valid option?

In this study we demonstrate our Radiology Department's experience in utilizing low dose (half the normal dose) lung perfusion radionuclide scanning for pregnant patients as the initial investigation for suspected pulmonary embolism (PE). Secondly; we highlight the radiation dose reduction advantages of nuclear medicine imaging over multi-detector computed tomography in this group. We performed a retrospective study of 21 consecutive pregnant women who presented with suspected PE. These patients underwent either lung perfusion scanning or CT pulmonary angiography (CTPA), over a two-year period (May 2005 to July 2007). 19 patients of the cohort studied underwent low dose perfusion-only scintigraphy, with half the usual dose of radionuclide activity. All scans were considered of diagnostic quality. No patient in our study required a ventilation scan. No patient with a negative perfusion scan represented during the 3 month follow up period with PE. We conclude, nuclear medicine imaging is an effective initial investigation for pregnant patients with suspected PE. While scinitigraphy is associated with a greater fetal radiation dose than CTPA, it imparts a lower maternal dose and significantly lower dose to radiosensitive tissues such as breast.