MDCT-based Finite Element Analysis of Vertebral Fracture Risk: What Dose is Needed?

PurposeThe aim of this study was to compare vertebral failure loads, predicted from finite element (FE) analysis of patients with and without osteoporotic vertebral fractures (OVF) at virtually reduced dose levels, compared to standard-dose exposure from multidetector computed tomography (MDCT) imaging and evaluate whether ultra-low dose derived FE analysis can still differentiate patient groups.Materials and MethodsAn institutional review board (IRB) approval was obtained for this retrospective study. A total of 16 patients were evaluated at standard-dose MDCT; eight with and eight without OVF. Images were reconstructed at virtually reduced dose levels (i.e. half, quarter and tenth of the standard dose). Failure load was determined at L1-3 from FE analysis and compared between standard, half, quarter, and tenth doses and used to differentiate between fracture and control groups.ResultsFailure load derived at standard dose (3254909N and 3794 +/- 984N) did not significantly differ from half (3390 +/- 890N and 3860 +/- 1063N) and quarter dose (3375 +/- 915N and 3925 +/- 990N) but was significantly higher for one tenth dose (4513 +/- 1762N and 4766 +/- 1628N) for fracture and control groups, respectively. Failure load differed significantly between the two groups at standard, half and quarter doses, but not at tenth dose. Receiver operating characteristic (ROC) curve analysis also demonstrated that standard, half, and quarter doses can significantly differentiate the fracture from the control group.ConclusionThe use of MDCT enables a dose reduction of at least 75% compared to standard-dose for an adequate prediction of vertebral failure load based on non-invasive FE analysis.