Automated 3D Rendering of Ribs in 110 Polytrauma Patients: Strengths and Limitations.

RATIONALE AND OBJECTIVES: To evaluate the strengths and limitations of a rib-unfolding software in a polytrauma context. MATERIALS AND METHODS: Chest computed tomography (CT) examinations of 110 patients were reviewed for specific detection of rib fractures using: (1) transverse CT sections ± multiplanar reformattings (ie, the standard of reference), and (2) unfolded rib images reconstructed by the CT Bone Reading software with the possibility of rib analysis along their long axis and creation of standard orthogonal views in different orientations of any area suspected of fracture. RESULTS: The software provided complete reconstruction of the whole rib cage in 94 patients (85.5%) and partially incomplete reconstruction in 16 patients (14.5%). The percentage of ribs inadequately reconstructed was 1.5% (40 of 2640 ribs), mainly related to unfused epiphyses (13 of 40), costal hypoplasia (8 of 40), and vertebral fracture (6 of 40). The sensitivity and specificity in detecting rib fractures at a per-patient, per-rib, and per-costal arc level ranged from 0.73 to 0.84 and 0.99 to 1, respectively. At a costal arc level, the reader's misinterpretations accounted for 67% (4 of 6) of false-positive and 24% (20/84) of false-negative results, and interpretive difficulties were encountered for single-cortex fractures or fractures at the extremities of the costal shaft. CONCLUSIONS: An accurate diagnosis of rib fracture was achieved with the reading of unfolded rib images. In a polytrauma context, the evaluated system could facilitate rib analysis.