Abstract # 151

Title
Rate of Significant Misses in Resident Preliminary CT Head On-Call Reports

Authors
J. Cai (PGY-4), J. Chankowsky, J. Taylor

Objective: To determine the rate and most common clinically significant misses in radiology residents’ on-call CT head C- reports at our institution. 

Methods
This retrospective study reviewed 848 cases of CT head without IV contrast performed during on call hours on the 1st, 12th, and 24th day of every month between July 1, 2017 and June 30, 2018 at two university hospital sites – the Montreal General Hospital and Royal Victoria Hospital. Final radiology staff report was used as standard and only RADPEER type 3 and 4 misses were included. All identified and equivocal cases were reviewed by a subspecialty neuroradiologist. 

Results
Out of 848 cases reviewed, 12 cases were identified to contain either a RADPEER type 3 or 4 miss, a miss rate of 1.4%. Out of the 12 cases, 4 cases were each missed by PGY-2, PGY-3, and PGY-4 residents on call respectively. None of the cases were missed by a PGY-5 resident during call. Our institution has a graded call system with call duty more heavily distributed to PGY-2 and PGY-3 residents than PGY-4 and PGY-5 residents. Therefore, frequency of clinically significant misses by training level is expressed as the number of calls per missed finding, with 9.25 calls, 14.25 calls, and 8 calls for PGY-2, 3, and 4 respectively. 
The most frequently missed findings were subdural hygroma with mass effect in acute trauma (25%), acute ischemia (25%), calvarial fracture (17%), and new hydrocephalus (17%). 
Conclusion
Rate of RADPEER type 3 and 4 misses in radiology resident on call preliminary reports for CT Head C- within our institution was 1.4%, no higher than that published in literature. The most frequently missed findings were traumatic subdural hygroma, acute ischemia, calvarial fracture and new hydrocephalus. None of the significant findings were missed by PGY-5 residents. Otherwise, there is no correlation between the level of training and frequency of significant missed findings on CT head C-.