Correct!
4. Filling defects indicating pulmonary embolism are sometimes seen on non-contrast images and have a high PPV for PE.
Tatco and Piedad (1) preformed a retrospective review of contrast CT images done under a PE protocol for 121 patients suspected of having pulmonary embolism. They then reviewed non-contrast images from the 25 patients who had a positive PE seen on the contrast CT images. They found that in nine of those patients an intravascular filling defect was visible even on the non-contrast images. They called this the “hyperdense lumen sign” and found the positive predictive value was 90%. The “hyperdense lumen sign” was more often seen on central rather than peripheral intravascular filling defects.
In a patient with acute, massive pulmonary embolism experiencing hemodynamic instability in the absence of a clear contraindication, the treatment of choice is: (Click on the correct answer to proceed to the next panel)