Comparison of short TE CT-like MRI sequences and UHR-CT in cadaveric wrist study

To evaluate the performance of CT-like MRI sequences (gradient echo with radial k-space filling (GRE), pointwise encoding time reduction with radial acquisition (PETRA), radial Ultrashort Echo Time (UTE)) versus ultra-high-resolution CT (UHR-CT) in assessing carpal bones and soft tissue calcifications in cadaveric wrists.

Five anonymized cadaveric forearm specimens were imaged using a 3 T MRI system with GRE, PETRA, and radial UTE sequences, alongside UHR-CT. Evaluated parameters included bone contours, carpal bone dimensions, cortical thickness, lesion size and soft tissue calcifications. Detection and diagnostic confidence of soft tissue calcifications were graded, and Contrast-to-Noise Ratio (CNR) was assessed for various tissues.

GRE provided the clearest bone contour visualization, closely matching UHR-CT, with a mean difference of less than 1 mm (p = 0.9). Geode sizes were underestimated by 16.1 % on GRE, 15.6 % on PETRA, and 22.5 % on radial UTE. GRE showed the highest CNR for bone (33.6 ± 15.4), outperforming PETRA (15.8 ± 8.5) and radial UTE (11.4 ± 8.1). Cortical thickness was overestimated significantly by PETRA (p = 0.05) and radial UTE (p = 0.009), but not by GRE (p = 0.5). GRE detected the most calcifications, but over 75 % of hypodense calcifications remained undetected. Overall, GRE offered the best bone contour visualization and CNR, while PETRA and radial UTE were better at distinguishing calcified tissue from tendons.

CT-like MRI sequences accurately assess bone morphology, with GRE offering the best bone contour visualization and CNR.