Reading it right: On-call rads adeptly interpret triple-rule-out CT studies

On-call resident interpretation of tripe-rule-out (TRO) CT studies in patients with acute chest pain is equal to final subspecialty attending interpretation in an overwhelming majority of cases, according to a study published in the July issue of Academic Radiology.

TRO CT assists in ruling out obstructive coronary artery disease, pulmonary embolism, acute aortic syndrome and other pathologies in a single evaluation for patients presenting with acute, undifferentiated or atypical chest pain. At many academic institutions, preliminary interpretation of these studies is conducted by radiology trainees. “For a number of imaging modalities and indications, a small but significant discrepancy rate between preliminary residents’ and final subspecialists’ interpretation has been demonstrated,” wrote the study’s lead author, K. Gabriel Garrett, MD, of the Medical University of South Carolina in Charleston, and colleagues.

Because it’s not clear whether trainees are adequately skilled in the interpretation of TRO CT studies to allow for safe use of this technique in the on-call setting, the researchers evaluated the performance of radiology residents in the interpretation of on-call, emergency TRO CT studies in patients with acute chest pain.

Using data from 617 on-call TRO studies, Garrett and colleagues compared the frequency of minor, major and all discrepancies in residents’ TRO interpretations to 609 emergent non-electrocardiography (ECG)-synchronized chest CT studies.

Results indicated minor discrepancies happened more often in the TRO group at 9.1 percent vs. 3.9 percent. There was, however, no difference in the frequency of major discrepancies, with the frequency being 2.1 percent in the TRO group and 2.8 percent in the control group.

The minor discrepancies in the TRO group were most often due to missed extrathoracic findings; missed liver lesions were the most frequent. Major discrepancies, on the other hand, were mostly cardiac and extracardiac vascular findings but didn’t result in unnecessary interventions, significant immediate changes in management or adverse patient outcomes.

“Our study supports the notion of offering TRO examinations in any emergency department with the appropriate technological infrastructure,” wrote the authors. “The results of our study suggest that TRO examinations should be perceived by the radiologic community as an imaging test that can be performed by every appropriately trained radiologist and not as a specialized examination type reserved for highly trained subspecialists,” they concluded.