[en] Detailed Monte Carlo gamma-ray transport calculations have been performed to study the coded-aperture imaging problem for a 37-pin bundle. Realistic geometries have been used for the test fuel bundle, its containment, the coded aperture and the gamma-ray detector. A high-Z gamma-ray filter placed near the coded aperture was found to enhance the signal change caused by voiding of test fuel, and a non-linear relationship was found between the amount of fuel voided and the resulting signal change. The signal changes appear to be large enough that gamma-ray imaging would be useful for a 37-pin bundle