Perfusion scintigraphy: diagnostic utility in pregnant women with suspected pulmonary embolic disease

Pulmonary embolism (PE) is a major preventable cause of maternal mortality during pregnancy and accurate diagnosis is essential. Computed tomography pulmonary angiography (CTPA) is a robust diagnostic test in non-pregnant patients with suspected PE. The potential latent carcinogenic effects of CTPA-related breast irradiation mandates careful use of this technique in young women. The aim of this study was to determine the efficacy of perfusion scintigraphy as the first line investigation in pregnant women with suspected PE. All pregnant women referred for radiological investigation of suspected PE in a 5-year period from January 2001 to December 2005 were included. Demographic data and imaging studies were reviewed. Subsequent pregnancy outcome was determined by case note review. One hundred and five consecutive patients had either perfusion scintigraphy (Q scan) (n = 94), CTPA (n = 9) or both (n = 2), one patient presented twice. Q scans were the first line investigation in 96 (91%) patients. Eighty-nine (92%) scans were normal, seven (7%) were non-diagnostic and one (1%) was high probability. One patient had a thromboembolic event 3 weeks post partum. No adverse events were reported during the follow-up period. Pulmonary embolic disease is uncommon in pregnancy. Perfusion scintigraphy in pregnant patients has an excellent diagnostic yield. The percentage of non-diagnostic scans is much lower than in other patient groups. Scintigraphy imparts a significantly lower breast dose than CTPA and should be used as the first-line investigation in most pregnant patients with suspected PE