What is the most appropriate diagnostic test when a pulmonary embolus (PE) is suspected in a pregnant patient?
—Roberto Ramirez, MD, Chicago
If a pregnant woman develops symptoms consistent with PE, the two most commonly used diagnostic procedures are ventilation-perfusion (V/Q) scan and spiral CT. Spiral CT is now the preferred diagnostic technique because it is less invasive than the V/Q scan, better able to determine the presence of other abnormal conditions, such as pneumonia, and better able to confirm the diagnosis of PE. The sensitivity and specificity of the spiral CT for establishing the diagnosis of PE is about 95%, while 40%-60% of V/Q scan findings are inconclusive. If a lead barrier is placed over the abdomen, radiation exposure of the fetus during a CT scan is extremely low and not a reason for concern.
—Daniel R. Mishell Jr, MD (116-2)