Jaw and maxillofacial bone lesions encompass a wide variety of both neoplastic and non-neoplastic pathologies.These lesions can arise from various tissues,including bone,cartilage,and soft tissue,each presenting disti...Jaw and maxillofacial bone lesions encompass a wide variety of both neoplastic and non-neoplastic pathologies.These lesions can arise from various tissues,including bone,cartilage,and soft tissue,each presenting distinct challenges in diagnosis and treatment.While some pathologies exhibit characteristic imaging features that aid in diagnosis,many others are nonspecific.This overlap often necessitates a multimodal imaging approach,combining techniques such as radiographs,computed tomography,and magnetic resonance imaging to achieve a diagnosis or narrow the diagnostic considerations.This article provides a comprehensive review of the imaging approach to jaw and maxillofacial bone tumors,including updates on the 2022 World Health Organization classification of these tumors.The relevant anatomy of the jaw and dental structures that is important for accurate imaging interpretation is discussed.展开更多
Transcranial electrical stimulation （TCES） is effective in treating many conditions, but it has not been possible to accurately forecast current density within the complex anatomy of a given subject＇s head. We soug...Transcranial electrical stimulation （TCES） is effective in treating many conditions, but it has not been possible to accurately forecast current density within the complex anatomy of a given subject＇s head. We sought to predict and verify TCES current densities and determine the variability of these current distributions in patient-specific models based on magnetic resonance imaging （MRI） data. Two experiments were performed. The first experiment estimated conductivity from MRIs and compared the current density results against actual measurements from the scalp surface of 3 subjects. In the second experiment, virtual electrodes were placed on the scalps of 18 subjects to model simulated current densities with 2 mA of virtually applied stimulation. This procedure was repeated for 4 electrode locations. Current densities were then calculated for 75 brain regions. Comparison of modeled and measured external current in experiment 1 yielded a correlation of r = .93. In experiment 2, modeled individual differences were greatest near the electrodes （ten-fold differences were common）, but simulated current was found in all regions of the brain. Sites that were distant from the electrodes （e.g. hypothalamus） typically showed two- fold individual differences. MRI-based modeling can effectively predict current densities in individual brains. Significant variation occurs between subjects with the same applied electrode configuration. Individualized MRI- based modeling should be considered in place of the 10-20 system when accurate TCES is needed.展开更多
Background：The injury of the triangular fibrocartilage complex （TFCC） is a common cause of ulnar-sided wrist pain.The aim of this study was to investigate if the high-resolution 3T magnetic resonance imaging （MRI...Background：The injury of the triangular fibrocartilage complex （TFCC） is a common cause of ulnar-sided wrist pain.The aim of this study was to investigate if the high-resolution 3T magnetic resonance imaging （MRI） could demonstrate the detailed complex anatomy of TFCC in Chinese.Methods：Fourteen Chinese cadaveric wrists （from four men and three women;age range at death from 30 to 60 years;mean age at 46 years） and forty healthy Chinese wrists （from 20 healthy volunteers,male/female：10/10;age range from 21 to 53 years with a mean age of 32 years） in Beijing Jishuitan Hospital from March 2014 to March 2016 were included in this study.All cadavers and volunteers had magnetic resonance （MR） examination of the wrist with coronal T 1-weighted and proton density-weighted imaging with fat suppression in three planes,respectively.MR arthrography （MRAr） was performed on one of the cadaveric wrists.Subsequently,all 14 cadaveric wrists were sliced into 2 mm thick slab with band saw （six in coronal plane,four in sagittal plane,and four in axial plane）.The MRI features of normal TFCC were analyzed in these specimens and forty healthy wrists.Results：Triangular fibrocartilage,the ulnar collateral ligament,and the meniscal homolog could be best observed on images in coronal plane.The palmar and dorsal radioulnar ligaments were best evaluated in transverse plane.The ulnotriquetral and ulnolunate ligaments were best visualized in sagittal plane.The latter two structures and the volar and dorsal capsules were better demonstrated on MRAr.Conclusion：High-resolution 3T MRI is capable to show the detailed complex anatomy of the TFCC and can provide valuable information for the clinical diagnosis in Chinese.展开更多
Background：Hand injuries are very common in sports,such as skiing and ball sports.One of the major reasons causing hand and finger deformity is due to ligament and tendon injury.The aim of this study was to investiga...Background：Hand injuries are very common in sports,such as skiing and ball sports.One of the major reasons causing hand and finger deformity is due to ligament and tendon injury.The aim of this study was to investigate if the high-resolution 3T magnetic resonance imaging （MRI） can demonstrate the complex anatomy of the fingers and thumb,especially the tendons and ligaments,and provide the accurate diagnosis of clinically important fingers and thumbs deformity due to ligamentous and tendinous injuries during sport activities.Methods：Sixteen fresh un-embalmed cadaveric hands were harvested from eight cadavers.A total of 20 healthy volunteers＇ hands and 44 patients with fingers or thumb deformity due to sports-related injuries were included in this study.All subjects had MR examination with T1-weighted images and proton density-weighted imaging with fat suppression （PD FS） in axial,coronal,and sagittal plane,respectively.Subsequently,all 16 cadaveric hands were sliced into 2-mm thick slab with a band saw （six in coronal plane,six in sagittal plane,and four in axial plane）.The correlation of anatomic sections and the MRI characteristics of tendons of fingers and the ulnar collateral ligament （UCL） at the metacarpal phalangeal joint （MCPJ） of thumb between 20 healthy volunteers and 44 patients （confirmed by surgery） were analyzed.Results：The normal ligaments and tendons in 16 cadaveric hands and 20 volunteers＇ hands showed uniform low-signal intensity on all the sequences of the MRI.Among 44 patients with tendinous and ligamentous injuries in the fingers or thumb,12 cases with UCL injury at MCPJ of the thumb （Stener lesion =8 and non-Stener lesion=4）,6 cases with the central slip injury,12 cases with terminal tendon injury,and 14 cases with flexor digitorum profundus injury.The ligaments and tendons disruption manifested as increased signal intensity and poor definition,discontinuity,and heterogeneous signal intensity of the involved ligaments and tendons.Conclusions：Sports injury-related fingers and thumb deformity are relatively common.MRI is an accurate method for evaluation of the anatomy and pathologic conditions of the fingers and thumb.It is a useful tool for accurate diagnosis of the sports-related ligaments and tendons injuries in hand.展开更多
文摘Jaw and maxillofacial bone lesions encompass a wide variety of both neoplastic and non-neoplastic pathologies.These lesions can arise from various tissues,including bone,cartilage,and soft tissue,each presenting distinct challenges in diagnosis and treatment.While some pathologies exhibit characteristic imaging features that aid in diagnosis,many others are nonspecific.This overlap often necessitates a multimodal imaging approach,combining techniques such as radiographs,computed tomography,and magnetic resonance imaging to achieve a diagnosis or narrow the diagnostic considerations.This article provides a comprehensive review of the imaging approach to jaw and maxillofacial bone tumors,including updates on the 2022 World Health Organization classification of these tumors.The relevant anatomy of the jaw and dental structures that is important for accurate imaging interpretation is discussed.
基金supported by the Sutter Institute for Medical Researchthe Aaken Research Institute
文摘Transcranial electrical stimulation （TCES） is effective in treating many conditions, but it has not been possible to accurately forecast current density within the complex anatomy of a given subject＇s head. We sought to predict and verify TCES current densities and determine the variability of these current distributions in patient-specific models based on magnetic resonance imaging （MRI） data. Two experiments were performed. The first experiment estimated conductivity from MRIs and compared the current density results against actual measurements from the scalp surface of 3 subjects. In the second experiment, virtual electrodes were placed on the scalps of 18 subjects to model simulated current densities with 2 mA of virtually applied stimulation. This procedure was repeated for 4 electrode locations. Current densities were then calculated for 75 brain regions. Comparison of modeled and measured external current in experiment 1 yielded a correlation of r = .93. In experiment 2, modeled individual differences were greatest near the electrodes （ten-fold differences were common）, but simulated current was found in all regions of the brain. Sites that were distant from the electrodes （e.g. hypothalamus） typically showed two- fold individual differences. MRI-based modeling can effectively predict current densities in individual brains. Significant variation occurs between subjects with the same applied electrode configuration. Individualized MRI- based modeling should be considered in place of the 10-20 system when accurate TCES is needed.
文摘Background：The injury of the triangular fibrocartilage complex （TFCC） is a common cause of ulnar-sided wrist pain.The aim of this study was to investigate if the high-resolution 3T magnetic resonance imaging （MRI） could demonstrate the detailed complex anatomy of TFCC in Chinese.Methods：Fourteen Chinese cadaveric wrists （from four men and three women;age range at death from 30 to 60 years;mean age at 46 years） and forty healthy Chinese wrists （from 20 healthy volunteers,male/female：10/10;age range from 21 to 53 years with a mean age of 32 years） in Beijing Jishuitan Hospital from March 2014 to March 2016 were included in this study.All cadavers and volunteers had magnetic resonance （MR） examination of the wrist with coronal T 1-weighted and proton density-weighted imaging with fat suppression in three planes,respectively.MR arthrography （MRAr） was performed on one of the cadaveric wrists.Subsequently,all 14 cadaveric wrists were sliced into 2 mm thick slab with band saw （six in coronal plane,four in sagittal plane,and four in axial plane）.The MRI features of normal TFCC were analyzed in these specimens and forty healthy wrists.Results：Triangular fibrocartilage,the ulnar collateral ligament,and the meniscal homolog could be best observed on images in coronal plane.The palmar and dorsal radioulnar ligaments were best evaluated in transverse plane.The ulnotriquetral and ulnolunate ligaments were best visualized in sagittal plane.The latter two structures and the volar and dorsal capsules were better demonstrated on MRAr.Conclusion：High-resolution 3T MRI is capable to show the detailed complex anatomy of the TFCC and can provide valuable information for the clinical diagnosis in Chinese.
基金This study was supported by grants from the National Natural Science Foundation of China （No. 81371515, No. 81771809）, the Beijing Natural Science Foundation of China （No. 7142075）, the Capital Medical Development and Scientific Research Fund of China （No. 2016-2-1122）.
文摘Background：Hand injuries are very common in sports,such as skiing and ball sports.One of the major reasons causing hand and finger deformity is due to ligament and tendon injury.The aim of this study was to investigate if the high-resolution 3T magnetic resonance imaging （MRI） can demonstrate the complex anatomy of the fingers and thumb,especially the tendons and ligaments,and provide the accurate diagnosis of clinically important fingers and thumbs deformity due to ligamentous and tendinous injuries during sport activities.Methods：Sixteen fresh un-embalmed cadaveric hands were harvested from eight cadavers.A total of 20 healthy volunteers＇ hands and 44 patients with fingers or thumb deformity due to sports-related injuries were included in this study.All subjects had MR examination with T1-weighted images and proton density-weighted imaging with fat suppression （PD FS） in axial,coronal,and sagittal plane,respectively.Subsequently,all 16 cadaveric hands were sliced into 2-mm thick slab with a band saw （six in coronal plane,six in sagittal plane,and four in axial plane）.The correlation of anatomic sections and the MRI characteristics of tendons of fingers and the ulnar collateral ligament （UCL） at the metacarpal phalangeal joint （MCPJ） of thumb between 20 healthy volunteers and 44 patients （confirmed by surgery） were analyzed.Results：The normal ligaments and tendons in 16 cadaveric hands and 20 volunteers＇ hands showed uniform low-signal intensity on all the sequences of the MRI.Among 44 patients with tendinous and ligamentous injuries in the fingers or thumb,12 cases with UCL injury at MCPJ of the thumb （Stener lesion =8 and non-Stener lesion=4）,6 cases with the central slip injury,12 cases with terminal tendon injury,and 14 cases with flexor digitorum profundus injury.The ligaments and tendons disruption manifested as increased signal intensity and poor definition,discontinuity,and heterogeneous signal intensity of the involved ligaments and tendons.Conclusions：Sports injury-related fingers and thumb deformity are relatively common.MRI is an accurate method for evaluation of the anatomy and pathologic conditions of the fingers and thumb.It is a useful tool for accurate diagnosis of the sports-related ligaments and tendons injuries in hand.
