Lung Scintigraphy Outperforms CTA in Excluding PE in Pregnant Patients

Lung scintigraphy may be more reliable than pulmonary CT angiography (CTA) for identifying or excluding pulmonary embolism (PE) in pregnant patients, according to a study published in the November issue of the American Journal of Roentgenology. PE is the leading cause of maternal death in pregnancy. CTA is the imaging modality of choice for the diagnosis of PE, however, lung scintigraphy has been shown to produce better diagnostic quality images more often than CTA in pregnant patients.
 
“Our study analyzed 28 CTA studies and 25 lung scintigraphy studies performed on a group of 50 patients,” says Carole A. Ridge, MD, lead author of the study. “The results showed that lung scintigraphy is more reliable than CTA for the diagnosis of PE. Only one out of 25 lung scintigraphic studies was inadequate for diagnosis, compared to 10 out of 28 CTA examinations that were found to be inadequate for diagnosis.” Examinations were considered inadequate when poor image quality prohibited a diagnosis.
 
“During CTA in pregnant patients, it is hard to achieve optimal image quality because of the hemodynamic effects of pregnancy,” says Ridge. “Our findings confirm what recent reports in the literature have suggested—CTA is less reliable for the diagnosis of PE in pregnant patients. Lung scintigraphy is more reliable than CTA for the diagnosis or exclusion of PE in pregnant patients and should be considered the imaging technique of choice unless the CTA image technique can be optimized for the pregnant patient.”
 
— Source: American Roentgen Ray Society