JAMA -- Abstract: Clinical Validity of a Negative Computed Tomography Scan in Patients With Suspected Pulmonary Embolism: A Systematic Review, April 2

Articles such as these, really help in further promoting the use of a specific modality. Though already implemented in clinical practice in most hospitals and countries in the world, this meta-analysis puts things in perspective. The negative predictive value for ruling out pulmonary thrombo-embolism is almost 99%, even with a single slice spiral CT scanner. There are advantages to using a multi-slice scanner especially for distal emboli, but a negative CT on a single slice spiral seems to be good enough. The question is whether identifying distal emboli makes a difference to management.

JAMA -- Abstract: Clinical Validity of a Negative Computed Tomography Scan in Patients With Suspected Pulmonary Embolism: A Systematic Review, April 27, 2005, Quiroz et al. 293 (16): 2012