Background: During residency, radiology residents learn to interpret volumetric radiological images. The development of their competence for volumetric image interpretation, as opposed to 2D image reading, is not completely understood. The purpose of the present study was to investigate how competence for volumetric image interpretation develops in radiology residents and how this compares with competence development for 2D image interpretation, by studying resident scores on image-based items in digital radiology tests.
Methods: We reviewed resident scores on volumetric and 2D image-based test items in 9 consecutive semi-annual digital radiology tests that were carried out from November 2013 to April 2018. We assessed percentage-correct sum scores for all test items about volumetric images and for all test items about 2D images in each test as well as for all residents across the 9 tests (i.e. 4.5 years of test materials). We used a paired t-test to analyze whether scores differed between volumetric and 2D image-based test items in individual residents in postgraduate year (PGY) 0-5, subdivided in 10 half-year phases (PGY 0-0.5, 0.5-1.0, 1.0-1.5 et cetera).
Results: The percentage-correct scores on volumetric and 2D image-based items showed a comparable trend of development, increasing in the first half of residency and flattening off in the second half. Chance-corrected scores were generally lower in volumetric than in 2D items (on average 1-5% points). In PGY 1.5-4.5, this score difference was statistically significant (p-values ranging from 0.02 to < 0.001), with the largest difference found in PGY 2.5 (mean: 5% points; 95% CI: -7.3 - -3.4). At the end of training in PGY 5, there was no statistically significant score difference between both item types.
Conclusions: The development of competence in volumetric image interpretation fits a similar curvilinear growth curve during radiology residency as 2D image interpretation competence in digital radiology tests. Although residents performed significantly lower on volumetric than 2D items in PGY 1.5-4.5, we consider the magnitude of this difference as relatively small for our educational setting and we suggest that throughout radiology training there are no relevant differences in the development of both types of competences, as investigated by digital radiology tests.
Keywords: Clinical competence; Educational measurement; Internship and residency; Learning; Radiology.