ObjectivesThe objectives of this study were to compare arterial and venous contrast medium extravasation in severe pelvic injury detected by ante- and post-mortem multi-detector CT (MDCT) and determine whether vascular injury is associated with certain types of pelvic fracture.MethodsWe retrospectively included two different cohorts of blunt pelvic trauma with contrast medium extravasation shown by MDCT. The first group comprised 49 polytrauma patients; the second included 45 dead bodies undergoing multi-phase post-mortem CT-angiography (MPMCTA). Two radiologists jointly reviewed each examination concerning type, site of bleeding and pattern of underlying pelvic ring fracture.ResultsAll 49 polytrauma patients demonstrated arterial bleeding, immediately undergoing subsequent angiography; 42 (85%) had pelvic fractures, but no venous bleeding was disclosed. MPMCTA of 45 bodies revealed arterial (n = 33, 73%) and venous (n = 35, 78%) bleeding and pelvic fractures (n = 41, 91%). Pelvic fracture locations were significantly correlated with ten arterial and six venous bleeding sites in dead bodies, with five arterial bleeding sites in polytrauma patients.In dead bodies, arterial haemorrhage was significantly correlated with the severity of pelvic fracture according to Tile classification (p = 0.01), unlike venous bleeding (p = 0.34).ConclusionsIn severe pelvic injury, certain acute bleeding sites were significantly correlated with underlying pelvic fracture locations. MPMCTA revealed more venous lesions than MDCT in polytrauma patients. Future investigations should evaluate the proportional contribution of venous bleeding to overall pelvic haemorrhage as well as its clinical significance.

Objective To show that for the MRI workup of non-specific low back pain and/or lumbar radiculopathy, the acquisition of T1weighted sequences in the sagittal plane could be waived when using an FSE T2-weighted Dixon sequence. Materials and methods Three musculoskeletal radiologists retrospectively reviewed fifty lumbar spine MRI examinations performed for non-specific low back pain and/or lumbar radiculopathy. Two protocols were separately analyzed in the sagittal plane: a standard protocol (T1-weighted, in-phase, and water-only images of an FSE T2-weighted Dixon sequence) and a simplified protocol (fat-only, in-phase, and water-only images of an FSE T2-weighted Dixon sequence). Eight items usually assessed on T1-weighted sequences were analyzed for each of the vertebrae (n = 250), vertebral endplates (n = 500), vertebral corners (n = 1000), foramina (n = 500), lamina (n = 500), and facet joints (n = 500). Interchangeability of these protocols was tested using the individual equivalence index. A decrease in interobserver agreement of ≥ 5% when one reader used the simplified protocol compared with when both readers used the standard protocol was considered clinically significant. Interreader and intrareader agreement were assessed using kappa statistics. Rates of findings with each protocol were compared using odd ratios. Results The standard and simplified protocols were interchangeable (range of upper bound of the 95%CI of individual equivalence index = 0.25 to 1.38%). Intraprotocol and interprotocol interreader kappa values were similar (0.253-0.671 vs. 0.236-0.723, respectively). Rates of findings were not statistically significantly different (p ≥ 0.074), or were higher with the simplified protocol (p ≤ 0.036). Conclusion In our target population, a single sagittal T2-weighted Dixon sequence may replace the recommended combination of T1-, T2-, and fat-suppressed T2-weighted sequences. Key Points • In patients with non-specific low back pain or lumbar radiculopathy, spine MRI in the sagittal plane could be limited to a single FSE T2-weighted Dixon sequence, hereby reducing the acquisition time. • A simplified protocol of spine MRI in the sagittal plane combining FSE T2-weighted Dixon sequence provides the same information as a standard protocol including T1-, T2-, and fat-suppressed T2-weighted sequences for the workup of degenerative lumbar spine lesions. • For some findings shown on the simplified protocol, such as focal bone marrow replacement lesions or signs of infection, additional sequences including pre-and post-contrast T1-weighted sequences may be required, as is currently the case when using the standard protocol.

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