Internal Derangement of the Wrist and Hand

2019 ◽  
pp. 210-231
Author(s):  
Apostolos H. Karantanas
Keyword(s):  
High Resolution ◽  
Soft Tissue ◽  
Wide Spectrum ◽  
Nerve Entrapment ◽  
Internal Derangement ◽  
Imaging Findings ◽  
Ct Arthrography ◽  
Imaging Methods ◽  
High Resolution Mri ◽  
Entrapment Syndromes

Chapter 106 discusses the normal MRI anatomy and imaging findings of the major and common disorders leading to internal derangements of the wrist and hand including osteonecrosis (ON) of the scaphoid and lunate bones, tendon and ligamentous injuries, and common nerve entrapment syndromes. The anatomy of the wrist and hand is complex. A wide spectrum of traumatic, inflammatory, and degenerative conditions affects the wrist and hand. High-resolution MRI of the wrist and hand and MRA of the wrist provide excellent evaluation of the osseous and soft tissue structures and in many instances represent the study of choice. Radiography, CT, arthrography, CTA, and diagnostic US represent the alternative and/or complementary imaging methods in the evaluation of these structures.

scholarly journals Neurogenic thoracic outlet syndrome: current diagnostic criteria and advances in MRI diagnostics

2015 ◽  
Vol 39 (3) ◽  
pp. E7 ◽  
Author(s):  
Stephen T. Magill ◽  
Marcel Brus-Ramer ◽  
Philip R. Weinstein ◽  
Cynthia T. Chin ◽  
Line Jacques
Keyword(s):  
High Resolution ◽  
Diagnostic Criteria ◽  
Thoracic Outlet Syndrome ◽  
Nerve Compression ◽  
Case Examples ◽  
Neurogenic Thoracic Outlet Syndrome ◽  
High Resolution Mri ◽  
Diagnostic Modalities ◽  
Mri Diagnostics ◽  
Entrapment Syndromes

Neurogenic thoracic outlet syndrome (nTOS) is caused by compression of the brachial plexus as it traverses from the thoracic outlet to the axilla. Diagnosing nTOS can be difficult because of overlap with other complex pain and entrapment syndromes. An nTOS diagnosis is made based on patient history, physical exam, electrodiagnostic studies, and, more recently, interpretation of MR neurograms with tractography. Advances in high-resolution MRI and tractography can confirm an nTOS diagnosis and identify the location of nerve compression, allowing tailored surgical decompression. In this report, the authors review the current diagnostic criteria, present an update on advances in MRI, and provide case examples demonstrating how MR neurography (MRN) can aid in diagnosing nTOS. The authors conclude that improved high-resolution MRN and tractography are valuable tools for identifying the source of nerve compression in patients with nTOS and can augment current diagnostic modalities for this syndrome.

scholarly journals Real-Time High-Resolution MRI Endoscopy at up to 10 Frames per Second

BME Frontiers ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xiaoyang Liu ◽  
Parag Karmarkar ◽  
Dirk Voit ◽  
Jens Frahm ◽  
Clifford R. Weiss ◽  
...  
Keyword(s):  
High Resolution ◽  
Soft Tissue ◽  
Real Time ◽  
Large Animal ◽  
Motion Sensitivity ◽  
X Ray ◽  
High Resolution Mri ◽  
Endoscopy Ultrasound ◽  
Tissue Sensitivity

Objective. Atherosclerosis is a leading cause of mortality and morbidity. Optical endoscopy, ultrasound, and X-ray offer minimally invasive imaging assessments but have limited sensitivity for characterizing disease and therapeutic response. Magnetic resonance imaging (MRI) endoscopy is a newer idea employing tiny catheter-mounted detectors connected to the MRI scanner. It can see through vessel walls and provide soft-tissue sensitivity, but its slow imaging speed limits practical applications. Our goal is high-resolution MRI endoscopy with real-time imaging speeds comparable to existing modalities. Methods. Intravascular (3 mm) transmit-receive MRI endoscopes were fabricated for highly undersampled radial-projection MRI in a clinical 3-tesla MRI scanner. Iterative nonlinear reconstruction was accelerated using graphics processor units connected via a single ethernet cable to achieve true real-time endoscopy visualization at the scanner. MRI endoscopy was performed at 6-10 frames/sec and 200-300 μm resolution in human arterial specimens and porcine vessels ex vivo and in vivo and compared with fully sampled 0.3 frames/sec and three-dimensional reference scans using mutual information (MI) and structural similarity (3-SSIM) indices. Results. High-speed MRI endoscopy at 6-10 frames/sec was consistent with fully sampled MRI endoscopy and histology, with feasibility demonstrated in vivo in a large animal model. A 20-30-fold speed-up vs. 0.3 frames/sec reference scans came at a cost of ~7% in MI and ~45% in 3-SSIM, with reduced motion sensitivity. Conclusion. High-resolution MRI endoscopy can now be performed at frame rates comparable to those of X-ray and optical endoscopy and could provide an alternative to existing modalities, with MRI’s advantages of soft-tissue sensitivity and lack of ionizing radiation.

Use of High-Resolution Ultrasound in Evaluation of the Forefoot to Differentiate Forefoot Nerve Entrapments

2005 ◽  
Vol 95 (5) ◽  
pp. 429-432 ◽  
Author(s):  
Brian R. Kincaid ◽  
Stephen L. Barrett
Keyword(s):  
High Resolution ◽  
Peripheral Nerves ◽  
Corticosteroid Injection ◽  
Nerve Entrapment ◽  
High Frequency Ultrasound ◽  
Forefoot Pain ◽  
Plantar Plate ◽  
Nerve Entrapments ◽  
Entrapment Syndromes ◽  
Frequency Ultrasound

Forefoot pain can have single or multiple etiologies, and frequently pain is attributed solely to a forefoot nerve entrapment. It is well known that forefoot nerve entrapments, such as Morton’s, can be falsely assumed to be the cause of forefoot pain when in fact other factors, such as plantar plate disturbances, are the true cause. Frequently, the cause of the patient’s forefoot pain starts as a forefoot nerve entrapment, but then, as a result of treatment with a corticosteroid injection, other pathologies manifest, such as plantar plate rupture. The development of high-resolution, high-frequency ultrasound scanners has opened the door to in-depth examination of peripheral nerves as well as small pericapsular and intracapsular joint structures of the foot and ankle. In the hands of an experienced clinician, ultrasound can play an important role in differentiating nerve lesions and entrapment syndromes from nonneurogenic pain generators, such as tendons, ligaments, fasciae, and joint capsules. The focus of this article is the forefoot, where differentiation of neuroma, neuritis, and capsulitis can be difficult. (J Am Podiatr Med Assoc 95(5): 429–432, 2005)

Functional information from magnetic resonance imaging

1995 ◽  
Vol 53 ◽  
pp. 84-85
Author(s):  
Alan P. Koretsky ◽  
Afonso Costa e Silva ◽  
Yi-Jen Lin
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Cancer Biology ◽  
Imaging Modality ◽  
Magnetic Resonance Images ◽  
Great Success ◽  
Functional Information ◽  
Resonance Imaging ◽  
High Resolution Mri

Magnetic resonance imaging (MRI) has become established as an important imaging modality for the clinical management of disease. This is primarily due to the great tissue contrast inherent in magnetic resonance images of normal and diseased organs. Due to the wide availability of high field magnets and the ability to generate large and rapidly switched magnetic field gradients there is growing interest in applying high resolution MRI to obtain microscopic information. This symposium on MRI microscopy highlights new developments that are leading to increased resolution. The application of high resolution MRI to significant problems in developmental biology and cancer biology will illustrate the potential of these techniques.In combination with a growing interest in obtaining high resolution MRI there is also a growing interest in obtaining functional information from MRI. The great success of MRI in clinical applications is due to the inherent contrast obtained from different tissues leading to anatomical information.

High Resolution MRI Can Help Determine Tumor Resectability in Cases of Benign Sciatic Notch Lesions

2006 ◽  
Vol 22 (06) ◽  
Author(s):  
Robert Spinner ◽  
Toshiki Endo ◽  
Eric Dozois ◽  
Kimberly Amarami
Keyword(s):  
High Resolution ◽  
Sciatic Notch ◽  
High Resolution Mri
Sign in / Sign up

Export Citation Format

Share Document