Quantification of the accuracy of MRI generated 3D models of long bones compared to CT generated 3D models

• Published in: Medical engineering & physics Vol. 34; no. 3; pp. 357 - 363
• Main Authors: Rathnayaka, Kanchana, Momot, Konstantin I, Noser, Hansrudi, Volp, Andrew, Schuetz, Michael A, Sahama, Tony, Schmutz, Beat
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.04.2012; Elsevier
• Subjects: 3D models; Animals; Bioengineering; Biological and medical sciences; Bone (long); Cadavers; Computed tomography; Computer Simulation; Computerized, statistical medical data processing and models in biomedicine; Data processing; Femur; Femur - anatomy & histology; Femur - diagnostic imaging; Fracture Fixation - instrumentation; Fractures; Image processing; Imaging, Three-Dimensional - statistics & numerical data; Limbs; Magnetic resonance imaging; Magnetic Resonance Imaging - statistics & numerical data; Medical sciences; Models and simulation; Models, Anatomic; Models, Animal; MRI; Prostheses and Implants; Prosthesis Design; Radiation; Radiology; Segmentation; Sheep; Soft tissues; Statistical analysis; Statistics; Tomography, X-Ray Computed - statistics & numerical data; CT; Femur; MRI; 3D models; Radiodiagnosis; Image processing; Nuclear magnetic resonance imaging; Modeling; Osteoarticular system; Vertebrata; Three dimensional model; Mammalia; Animal; Medical imagery; Sheep; Computerized axial tomography; Artiodactyla; Long bone; Ungulata; Comparative study; Biomedical engineering
• ISSN: 1350-4533; 1873-4030
• DOI: 10.1016/j.medengphy.2011.07.027

Abstract Orthopaedic fracture fixation implants are increasingly being designed using accurate 3D models of long bones based on computer tomography (CT). Unlike CT, magnetic resonance imaging (MRI) does not involve ionising radiation and is therefore a desirable alternative to CT. This study aims to quantify the accuracy of MRI-based 3D models compared to CT-based 3D models of long bones. The femora of five intact cadaver ovine limbs were scanned using a 1.5 T MRI and a CT scanner. Image segmentation of CT and MRI data was performed using a multi-threshold segmentation method. Reference models were generated by digitising the bone surfaces free of soft tissue with a mechanical contact scanner. The MRI- and CT-derived models were validated against the reference models. The results demonstrated that the CT-based models contained an average error of 0.15 mm while the MRI-based models contained an average error of 0.23 mm. Statistical validation shows that there are no significant differences between 3D models based on CT and MRI data. These results indicate that the geometric accuracy of MRI based 3D models was comparable to that of CT-based models and therefore MRI is a potential alternative to CT for generation of 3D models with high geometric accuracy.