Hip cartilage thickness measurement accuracy improvement
Introduction
Accurate thickness measurement of sheet-like (or plate-like) thin anatomical structures, such as articular cartilage, has become increasingly important in clinical applications. Osteoarthritis or posttraumatic articular injuries can result in changes to the morphology of articular cartilage. Measuring and monitoring changes of articular cartilage thickness can play a critical role in the management of patients with disease or injury to those tissues.
The majority of studies for measuring the articular cartilage thickness have focused on the knee joint [1], [2], [3], [4], [5], where the cartilage surfaces do not fit tightly. Only a limited number of studies have addressed cartilage abnormalities in the hip joint [6], [7]. In the hip, both the femoral head and the acetabulum are covered with cartilage. The ball and socket constitution of the hip joint, with strong capsule and ligaments, does not permit discrimination of the articular cartilage of the femoral head from the acetabulum. To allow separation of acetabular and femoral cartilages in MR images, the original continuous leg traction technique was used during MR imaging [8]. However, in many cases, the joint space between the femoral cartilage and acetabular cartilage is narrow despite traction. In a related study, in case two tubular structures are close to each other, Krissian et al., analyzed the cause of its influence on centerline detection of tubular structures [9]. Therefore, for the two articular cartilages of the hip joint, it is imperative to investigate whether one can impose a limitation on the accuracy of thickness measurement, but no studies as of yet have assessed this limitation.
In this paper, we develop a mathematical model for two adjacent sheet structures based on the (one-dimensional) 1D signal intensity profile along the normal direction of two sheet structures separated by a small distance, and then perform numerical simulation of MR imaging and postprocessing for thickness measurement. The thickness is defined as the distance between the two sides of the edges, which are the zero-crossings points of the second directional derivatives along the normal direction. We compare the measured thickness of a single sheet structure with that of the sheet structure influenced by the adjacent sheet structure and confirm that considerable underestimation error in thickness measurement occurred due to the influence of the adjacent sheet structure. To improve measurement accuracy, we propose a new measurement technique based on matching a modeled intensity profile with an actual intensity profile observed in the MR data set. Using the phantoms and two cadaveric human hip joints, we present results showing that the influence of the adjacent sheet structure is eliminated, and the improved technique is more accurate than the conventional zero-crossings method in measuring the thickness of two adjacent sheet structures.
Section snippets
Mathematical model definition
Let Sheet1 and Sheet2 represent the two adjacent sheet structures, which model the two cartilages in the hip joint. Fig. 1a shows a 2D representation of two adjacent sheet structures on the x–y plane. In this study, our investigations will focus on assessing the influence of Sheet1 on thickness measurement of Sheet2 in two dimensions (on the x–y plane). In Fig. 1a, the in-plane rotation angle θ is defined as the angle formed by the x-axis and the sheet normal direction , where
Simulation and phantom measurements
Theoretical simulations confirm and explain that Sheet1 affects the accuracy in the measured thickness of Sheet2. To validate the theoretical simulations, we compare the simulated thickness with the average of actually measured thickness determined from MR images of acrylic phantoms. We also compare the measured thickness of Sheet2 with that of a single sheet, assuming that the true thickness τ of a single sheet is the same as the true thickness τ2 of Sheet2. In the simulations, we mainly used
Discussion
As for two adjacent sheet structures (Sheet1 and Sheet2), such as femoral cartilage and acetabular cartilage in the hip joint, we performed the simulation measurement, phantom measurement and articular cartilage thickness measurement. The experimental results showed considerable underestimation in thickness measurement occurred due to the influence of the adjacent sheet structure. In order to remove the influence of the adjacent sheet and calibrate measurement bias, an improved measurement
Summary
In the hip joint, in which the femoral and acetabular cartilages are adjacent to each other. To investigate whether the accuracy in thickness measurement of femoral cartilage is influenced by acetabular cartilage, we developed a mathematical model for two adjacent sheet structures, which simulated the femoral and acetabular cartilages in the hip joint. MR imaging process and post\processing for thickness measurement are also modeled and simulated. Thickness is defined as the distance between
Acknowledgements
This work was partly supported by the Japan Society for the Promotion of Science (JSPS Research for the Future Program and JSPS Grant-in-Aid for Scientific Research (c) (2) 11680389). We are grateful to Doctor Hisashi Tanaka, Department of Radiology, Osaka University Graduate of Medicine, Japan, who provided the MR image Data.
Yuanzhi Cheng entranced into Graduate School of Mechatronics Engineering at Harbin Institute of Technology in 2002. He is currently completing the Ph.D. from Harbin Institute of Technology Graduate School of Mechatronics Engineering and Osaka University Graduate School of Medicine.
References (21)
- et al.
Use of novel interactive input devices for segmentation of articular cartilage from magnetic resonance images
OsteoArthritis Cartilage
(2005) - et al.
Considerations in measuring cartilage thickness using MRI: factors influencing reproducibility and accuracy
OsteoArthritis Cartilage
(2005) - et al.
Cartilage volume quantification via live wire segmentation
Acad Radiol
(2004) - et al.
Three-dimensional distribution of acetabular cartilage thickness in patients with hip dysplasia: a fully automated computational analysis of MR imaging
Osteoarthritis Cartilage
(2004) - et al.
Application of three-dimensional magnetic resonance image registration for monitoring hip joint diseases
Magn Reson Imaging
(2005) - et al.
Model-based detection of tubular structures in 3-D images
Comput Vision Image Understanding
(2000) - et al.
Quantitative assessment of patellar cartilage volume and thickness at 3. 0 Tesla comparing a 3D-fast low angle shot versus a 3D-true fast imaging with steady-state precession sequence for reproducibility
Invest Radiol
(2006) - et al.
Accuracy and precision of quantitative assessment of cartilage morphology by Magnetic Resonance Imaging at 3.0 T
Arthritis Rheum
(2005) - et al.
MR evaluation of the articular cartilage of the femoral head during traction
Acta Radiol
(1999) - et al.
The voxel sensitivity function in Fourier transform imaging: applications to magnetic resonance angiography
Magn Reson Med
(1995)
Cited by (14)
A mathematical simulation of the tip-apex distance and the calcar-referenced tip-apex distance for intertrochanteric fractures reduced with lag screws
2016, InjuryCitation Excerpt :The volume was approximately equal to the number of the plots multiplied by 0.008 mm3. A locus of the screw tip points was drawn based on the traversal method within the recommended cut-off range of 10–25 mm (i.e. diameter = 47 mm in Fig. 2), as described by Baumgaertner and Cheng et al. [3,15]. A Boolean intersect operation between TAD and CalTAD was taken as the overlapping region.
MR imaging of early hip joint degeneration
2011, Magnetic Resonance Imaging Clinics of North AmericaCitation Excerpt :Osteoarthritis and hip joint injuries can result in changes in cartilage morphology. There is increasing interest in measuring and monitoring changes of articular cartilage thickness in the management of patients with prior injury or findings of femoroacetabular impingement.8 MR imaging evaluation of articular cartilage within the acetabulum and femoral head can be difficult.
MR Imaging in Osteoarthritis: Hardware, Coils, and Sequences
2010, Magnetic Resonance Imaging Clinics of North AmericaCitation Excerpt :Morphologic evaluation of cartilage and labrum at the hip joint without intra-articular contrast is limited. Initial studies have focused on quantitative MR imaging of the hip,68,69,72,74 but segmentation of the femoral and acetabular cartilage layers at the hip is challenging, and frequently the two cartilage layers cannot be differentiated. To assess all tissues affected by OA, “whole-organ” MR imaging protocols are required.
MR Imaging in Osteoarthritis: Hardware, Coils, and Sequences
2009, Radiologic Clinics of North AmericaCitation Excerpt :Morphologic evaluation of cartilage and labrum at the hip joint without intra-articular contrast is limited. Initial studies have focused on quantitative MR imaging of the hip,68,69,72,74 but segmentation of the femoral and acetabular cartilage layers at the hip is challenging, and frequently the two cartilage layers cannot be differentiated. To assess all tissues affected by OA, “whole-organ” MR imaging protocols are required.
Optimal position and apex–subchondral bone distance of cannulated screws for internal fixation of femoral neck fracture: A radiological study
2023, Journal of Orthopaedic ResearchA novel lower bound for tip-apex distance
2022, European Journal of Trauma and Emergency Surgery
Yuanzhi Cheng entranced into Graduate School of Mechatronics Engineering at Harbin Institute of Technology in 2002. He is currently completing the Ph.D. from Harbin Institute of Technology Graduate School of Mechatronics Engineering and Osaka University Graduate School of Medicine.
Shuguo Wang received the B.S., M.S., and the Ph.D. degrees in Mechatronics from the Harbin Institute of Technology, Harbin, China. He has assumed the position of Professor at the School of Mechatronics Engineering at the Harbin Institute of Technology since 1992. He has published more than 100 papers in scientific journals. Professor Wang served as the Chair/Co-Chair on the many National and International Robotics Conference and also served on the National Science Foundation's Robotics Council from 1998 to 2005. In 1995, he received the Outstanding Senior Faculty Research Award from the Ministry of Education of China.
Takaharu Yamazaki received the B.S. and M.S. degrees from the Department of Medical Physics and Engineering in Allied Health Science and Ph.D. degree in Medical Science from Osaka University, Japan in 1998, 2000 and 2004, respectively. From 2004 to 2006 he was a Research Associate at the Department of Orthopaedics at Osaka University Graduate School of Medicine. Since 2006, he has been a Specially Appointed Lecturer at the Center for Advanced Medical Engineering and Informatics, Osaka University. His research interests include medical image processing and analysis, kinematics of skeletal joint, and biomechanics.
Jie Zhao received the Ph.D. degree from the Harbin Institute of Technology, Harbin, China in 1997. He is currently a Professor in Mechatronic Engineering Department Robotics Institute, Harbin Institute of Technology. Dr. Zhao is a member of the Intelligent Robot Professional Committee of China Artificial Intelligence Association. His research interests are concentrated on the multi-sensor integrated and control system technology, robotic teleoperation technology, medical robot technology, and bionic robotics.
Yoshikazu Nakajima received B.S. and M.S. degrees from Fukui University in1992 and 1994, respectively, and a Ph.D. degree from Osaka University in 1997. He is currently an Associate Professor of the Department of Bioengineering, School of Engineering, the University of Tokyo. He is also with the Department of Engineering Synthesis at School of Engineering and the Intelligent Modeling Laboratory, the University of Tokyo. His research interests include medical image processing, computer-integrated surgical systems and surgical informatics.
Shinichi Tamura received the B.S., M.S., and Ph.D. degrees in Electrical Engineering from Osaka University, Osaka, Japan, in 1966, 1968, and 1971, respectively. He is currently a Professor at the Graduate School of Medicine, Graduate School of Information Science and Technology, and the Center for Advanced Medical Engineering and Informatics, Osaka University. He has published more than 250 papers in scientific journals and received several awards from journals including Pattern Recognition and Investigative Radiology. His current research activities include works in the field of medical image analysis and its applications. Currently he is an Editorial Board member of International Journal of Computer Assisted Radiology and Surgery. Dr. Tamura is a member of the Institute of Electronics, Information and Communication Engineers of Japan, the Information Processing Society of Japan, the Japanese Society of Medical Imaging Technology, and the Japan Radiological Society.