There has been an explosion in recent years in the PE literature on CT scanning. Older literature, and even some current studies, emphasized the sensitivity of CT scanning for pulmonary embolism. In other words, how well does CT detect PE? The current trend in PE research is to report outcomes. So, a patient is evaluated for PE and the CT is negative. What is that patient's outcome (PE, DVT, death) at 30, 60, 90 days, etc? Dozens of studies in recent years have shown that patients generally have a superb outcome after negative CTs. Several recent studies have shown this, and in these studies the only imaging modality was CT (no ultrasound, etc). Pearl: Despite the difference in sensitivity for PE between single slice, multislice, and multidetector CT studies have shown that the outcome rates are relatively equal. Multidetector CT clearly picks up small, subsegmental clots better than single slice or 16, 32 slice CT. This might very well mean (according to some) that subsegmental (small, tiny) clots may not be that significant. We may very well be approaching an era where we don't treat small, peripheral clots. Pulmonary Embolism, second edition, Paul Stein 2007