Jadranka Stojanovska MD, MS, Presenter: Nothing to Disclose

Ruth C. Carlos MD, MS, Abstract Co-Author: Nothing to Disclose

Aamer Rasheed Chughtai MBBS, Abstract Co-Author: Nothing to Disclose

Aine Marie Kelly MD, Abstract Co-Author: Nothing to Disclose

Ella A. Kazerooni MD, Abstract Co-Author: Nothing to Disclose

To apply the appropriateness of computed tomography pulmonary angiography (CTPA) utilization using existing clinical decision rules in emergency department (ED) and to assess CTPA diagnostic yield by applying decision rules.

Institutional Review Board approval was obtained for this HIPPA-compliant prospective cohort study. A total of 602 consecutive adult ED patients undergoing CTPA for suspected pulmonary embolism (PE) formed the study population. Primary outcome was positive or negative for PE. PE rule-out criteria (PERC) and modified Wells (mWells) score were retrospectively calculated. Positive PERC (+PERC) was defined as having ≥1of the criteria met. Positive mWells (+mWells) was defined if the score was > 4. PE prevalence, percentage of CTPA examinations that could have been avoided, the diagnostic yield of CTPA among patients with -PERC compared to -mWells were calculated.

Of 602 patients in total, 61 (10%) were diagnosed with PE. By applying PERC and mWells, 17.6% (106/602) and 45 (261/602) of all CTPA examinations could have been avoided. The overall diagnostic yield of PERC was higher at 10% (59/602) compared to diagnostic yield of mWells of 8% (49/602) p<0.0001. Among patients with –PERC, the diagnostic yield for PE was 1.9% (2/106) compared to a diagnostic yield of positive PE of 4% (12/273) among patients with -mWells (p=0.004).

PERC is safer triaging decision tool than mWells that reduces the probability of PE to below 2% and should be applied in ED setting to avoid overutilization of CTPA.

The diagnostic yield of PE among negative cases by PERC (1.9%) is lower than diagnostic yield of PE among negative cases by mWells (4%). PERC is safer clinical decision rule than mWells that reduces PE posterior probability to below to 2% and it should be applied in ED setting to avoid overutilization of CTPA.

Stojanovska, J, Carlos, R, Chughtai, A, Kelly, A, Kazerooni, E, Appropriateness of Use of Computed Tomography Pulmonary Angiography by Emergency Department by Use of Decision Rules.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14000456.html