Abstract
Abstract
Background
Multiplanar reconstructions of computed tomography (CT) scans can alleviate issues with bone or joint positioning during scan acquisition. The repeatability of these reconstructions is dependent on human operators applying reconstruction criteria, and therefore is subject to error, which could affect measurement reliability for angular or spatial measurements made for orthopaedic surgery.
We describe a method for quantifying inter-reconstruction variability numerically and graphically using metadata from the CT header to find vectors describing reconstruction axis alignment. The approach is demonstrated using 3 sets of computed tomographic reconstructions of 24 vulpine femorotibial joints.
Results
Vectors describing axis alignments permitted identification and subsequent analysis of deviations from optimal alignment between reconstruction sets. For the worked example, alignment deviations equivalent to femoral abduction/adduction were nearly twice those for extension/flexion, and simulation of the effects of these deviations on measurements closely matched published data.
Conclusions
The method presented here is straightforward and permits numerical and graphical analysis of reconstruction variability. Reconstruction alignment variability should be considered before adopting new reconstruction criteria for clinical use, and evaluated whenever there is suspicion that reconstruction variability could unduly influence subsequent measurements. These evaluations may help drive improvements in reconstruction criteria. The methods described here could also be employed for comparing patient positioning between scans and between different scan modalities.
Publisher
Springer Science and Business Media LLC
Subject
Energy Engineering and Power Technology,Fuel Technology
Reference22 articles.
1. Davids JR, Marshall AD, Blocker ER, Frick SL, Blackhurst DW, Skewes E. Femoral anteversion in children with cerebral palsy - assessment with two and three-dimensional computed tomography scans. J Bone Jt Surg - Am Vol. 2003;85A:481–8.
2. Olesen TH, Torfing T, Overgaard S. MPR realignment increases accuracy when measuring femoral neck anteversion angle. Skelet Radiol. 2013;42:1119–25.
3. Riccio AI, Carney J, Hammel N, Stanley M, Cassidy J, Davids JR. Three-dimensional computed tomography for determination of femoral anteversion in a cerebral palsy model. J Pediatr Orthop. 2015;35:167–71.
4. Barnes DM, Anderson AA, Frost C, Barnes J. Repeatability and reproducibility of measurements of femoral and tibial alignment using computed tomography multiplanar reconstructions. Vet Surg. 2014;44:85–93.
5. Oxley B, Gemmill TJ, Pink J, Clarke S, Parry A, Baines S, et al. Precision of a novel computed tomographic method for quantification of femoral varus in dogs and an assessment of the effect of femoral malpositioning. Vet Surg. 2013;42:751–8.