UCSF

Rationale and objectives

Radiology expertise is dependent on the use of efficient search strategies. The aim of this study is to investigate the effect of teaching search strategies on trainee's accuracy in detecting lung nodules at computed tomography.

Materials and methods

Two search strategies, "scanning" and "drilling," were tested with a randomized crossover design. Nineteen junior radiology residents were randomized into two groups. Both groups first completed a baseline lung nodule detection test allowing a free search strategy, followed by a test after scanning instruction and drilling instruction or vice versa. True positive (TP) and false positive (FP) scores and scroll behavior were registered. A mixed-design analysis of variance was applied to compare the three search conditions.

Results

Search strategy instruction had a significant effect on scroll behavior, F(1.3) = 54.2, P < 0.001; TP score, F(2) = 16.1, P < 0.001; and FP score, F(1.3) = 15.3, P < 0.001. Scanning instruction resulted in significantly lower TP scores than drilling instruction (M = 10.7, SD = 5.0 versus M = 16.3, SD = 5.3), t(18) = 4.78, P < 0.001; or free search (M = 15.3, SD = 4.6), t(18) = 4.44, P < 0.001. TP scores for drilling did not significantly differ from free search. FP scores for drilling (M = 7.3, SD = 5.6) were significantly lower than for free search (M = 12.5, SD = 7.8), t(18) = 4.86, P < 0.001.

Conclusions

Teaching a drilling strategy is preferable to teaching a scanning strategy for finding lung nodules.