1.5 T magnetic resonance imaging generates accurate 3D proximal femoral models: Surgical planning implications for femoroacetabular impingement

Abstract

The objective of this study was to validate three‐dimensional (3D) proximal femoral surface models generated from a 1.5 T magnetic resonance imaging (MRI) by comparing these 3D models to those derived from the clinical “gold standard” of computed tomography (CT) scan and to ground‐truth surface models obtained by laser scans (LSs) of the excised femurs. Four intact bilateral cadaveric pelvis specimens underwent CT and MRI scans and 3D surface models were generated. Six femurs were extracted from these specimens, and the overlying soft tissues were removed. The extracted femurs were then laser scanned to produce a ground‐truth surface model. A 3D‐3D registration method was used to compare the signed and absolute surface‐to‐surface distances between the 3D models. Absolute agreement was evaluated using a 95% confidence interval (CI) derived from the precision of the LS ground‐truth. Paired samples t tests and Kolmogrov–Smirnov tests were performed to compare the differences between the signed and absolute surface‐to‐surface distances between the models. The average signed surface‐to‐surface distances for the MRI vs LS and MRI vs CT models were 0.07 and 0.16 mm, respectively. These differences fell within the 95% CI of ±0.20 mm indicating absolute agreement between the surface models generated from these modalities. The signed surface‐to‐surface distance was significantly smaller for MRI vs LS ground truth model as compared with the CT vs LS model. Femoral models derived from a 1.5 T MRI scan demonstrated absolute agreement with the clinical gold standard of CT‐derived models and were most like LS ground truth models of the excised femurs.

Three-dimensional curvature mismatch of the acetabular radius to the femoral head radius is increased in borderline dysplastic hips

“…On the one hand, MRI can visualize the cartilage surface. Besides, recent developments in image analysis techniques have enabled 3D morphological analysis based on MRI both from other groups and our own research [30,31]. Further investigations, which are based on an evaluation method that considers cartilage thickness, such as MRI, are necessary to validate the present results.…”

3D MRI Models of the Musculoskeletal System

“…Comparisons showed absolute agreement of signed surface-to-surface distances between all 3D models and that the 1.5-T MRI 3D model most closely represented the actual bone surface. 7 In a study evaluating the accuracy of automatic deep learning segmentation of 3D MRI models for planning periacetabular osteotomy in hip dysplasia, there was excellent correlation for femoral head coverage anteversion and inclination between manual segmentation of CT-based and automatic segmentation of MRI-based 3D models. 47 Specific software developed for the planning of periacetabular osteotomy was used to calculate anterior, posterior, and total femoral head coverage, anteversion, inclination, and the extrusion index.…”

“…Through these preparatory processes, CT-like contrasts of osseous structures can be synthesized using image subtraction postprocessing of dual gradient-recalled echo (GRE) pulse sequences such as with the Dixon technique 7 or mathematical and artificial intelligence (AI)-based processing, [10][11][12] bias-correction algorithm, and rescaling the images using an inverse-logarithmical algorithm in zero echo time (ZTE) MRI techniques. 5 Other volumetric 3D MRI techniques typically do not need preparatory processing before segmentation, such as balanced 3D steady-state coherent pulse sequences (e.g., True-FISP), 3D GRE sequences (e.g., volumetric interpolated breath-hold examination [VIBE]), and 3D fast spin and turbo spin-echo pulse sequences, for example, CUBE from GE Healthcare; Volume Isotropic Turbo Spin Echo Acquisition (VISTA) from Philips, and Sampling Perfection with Application Optimized Contrasts Using Different Flip Angle Evolution (SPACE) from Siemens.…”

“…2 The higher isotropic quality of improved 3D MRI acquisitions enables creating high-quality 3D MRI volume-and surface-rendered models that are more readily available and increasingly being adopted in clinical practice by many institutions. [3][4][5][6][7][8] A practical consideration for creating 3D MRI models is the need for additional time and expertise that can be limiting factors for the widespread use of 3D models. Nevertheless, 3D model postprocessing has become much more efficient over the last 20 years and is expected to improve further with newer and cutting-edge technology.Using 3D CT data, most automated bone segmentation techniques of stand-alone postprocessing software, such as Aquarius (TeraRecon), Vitrea (Vital images), and SyngoVia (Siemens), produce accurate 3D surface depictions of the bony structures based on the large difference of Hounsfield unit values of cortical bone and the surrounding soft tissues.…”

“…2 The higher isotropic quality of improved 3D MRI acquisitions enables creating high-quality 3D MRI volume-and surface-rendered models that are more readily available and increasingly being adopted in clinical practice by many institutions. [3][4][5][6][7][8] A practical consideration for creating 3D MRI models is the need for additional time and expertise that can be limiting factors for the widespread use of 3D models. Nevertheless, 3D model postprocessing has become much more efficient over the last 20 years and is expected to improve further with newer and cutting-edge technology.…”