Automatic rib unfolding in postmortem computed tomography: diagnostic evaluation of the OpenRib software compared with the autopsy in the detection of rib fractures.

OBJECTIVES: The main objective of this study was to evaluate the diagnostic performance of the OpenRib software against the gold standard of autopsy in the detection of rib fractures. The secondary objective was to measure inter-rater agreement between each radiological reader. MATERIALS AND METHODS: Thirty-six subjects who underwent postmortem CT and autopsy were included in this study. Rib fractures were first assessed during the autopsy by carefully dissecting and examining each rib. They were also independently evaluated by three readers using OpenRib software. This software produces from postmortem CT images a reformat of the rib cage and a display of all ribs in a single plane. Each reader was asked to determine if the rib was fractured and, if so, whether the fracture was single or multiple. RESULTS: After exclusions, 649 ribs were included in the statistical analysis. The two readers with a similar level of experience showed a satisfactory inter-rater agreement and a sensitivity of 0.73 and 0.83 with a specificity of 0.95 and 0.91. However, the experienced reader diagnosed significantly more fractures than the autopsy and the other two readers (p < 0.001). CONCLUSION: The use of automatic rib unfolding software in postmortem CT allows an efficient and accurate assessment of rib fractures and enables the diagnosis of fractures that cannot be detected during a standard autopsy. For now, this method seems to be the simplest that can be routinely performed; however, it requires training time in order to be sufficiently effective.

Automatic rib cage unfolding with CT cylindrical projection reformat in polytraumatized patients for rib fracture detection and characterization: Feasibility and clinical application.

OBJECTIVES: To assess the use of CT with unfolded cylindrical projection (UCP) for rib fracture detection and characterization. METHODS: The images from 60 polytraumatized patients who underwent whole body CT were evaluated for the presence and characterization of rib fractures (displaced or not, single or multiple). Two readers independently evaluated conventional CT images and UCP images in two readout sessions at least one month apart. All readouts were timed. A gold standard was established by two radiologists with 12 and 22 years of clinical experience based on the combined analysis of conventional and UCP reformats. RESULTS: Using UCP, the mean evaluation time was 27%-54% shorter (P = 0.01 and <0.0001) while maintaining a comparable diagnostic performance (sensitivity and specificity of 68.4-79.1% and 99.5-99.6% for conventional reformats and 70.6-91.0% and 96.8-97.7% for UCP) and a good reproducibility (Kappa of 0.71). The multiple fracture detection ratio of UCP was similar to that of conventional reformats (>80%). There were more false positives and false negatives using UCP and displaced fractures were harder to characterize. CONCLUSION: UCP yielded a diagnostic performance similar to that of conventional reformats for the detection of rib fractures with a good reproducibility and a noticeable reduction in evaluation time.

Added Value of Bone Subtraction in Dual-energy Digital Radiography in the Detection of Pneumothorax: Impact of Reader Expertise and Medical Specialty.

RATIONALE AND OBJECTIVES: This study aimed to determine the value of dual-energy thoracic radiography in the diagnosis of pneumothorax considering the reader's experience. MATERIALS AND METHODS: Forty patients with a suspected pneumothorax, imaged with dual-energy chest radiographs, were divided into two groups: those with pneumothorax as the final diagnosis (n = 19) and those without (n = 21). The images were analyzed by 36 readers (5 interns, 16 residents, 15 senior physicians) for the presence or absence of pneumothorax during three readout sessions at 2-week intervals: standard images alone (session 1), dual-energy images with bone subtraction alone (session 2), and a combination of the two (session 3). RESULTS: The number of correct responses increased 13.3% between sessions 1 and 2 (P < .001) and 9.4% between sessions 1 and 3 (P < .001). The mean sensitivity for pneumothorax detection was higher in sessions 2 (82%) and 3 (79%) compared to session 1 (70%). There was no statistically significant difference in specificity between the sessions. The number of correct responses for small volume pneumothoraces was higher in sessions 2 (10.6 ± 1.8) and 3 (10.1 ± 2.0) than in session 1 (8.9 ± 2.3), with a statistically significant difference between sessions 1 and 2 (P = .002) and between sessions 1 and 3 (P = .048). CONCLUSION: Bone subtracted dual-energy thoracic radiographs improve the detection sensitivity of pneumothorax, including in cases of small pneumothoraces, regardless of the reader's level or expertise.