Magnetic resonance imaging of the hand and wrist

Girgis, Wahid S.; Epstein, Robert E.

doi:10.1053/sroe.2000.7339

Cited by 14 publications

(12 citation statements)

References 40 publications

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“…10,11,14 Four characteristics associated with CTS have been identified in these types of structure/shape studies: enlargement of the median nerve, flattening of the median nerve, bowing of the transverse carpal ligament, and increased signal intensity of the median nerve on T2-weighted images. 5,11,12,23,24 Unfortunately, despite being frequently identified in patients with CTS, these MRI-apparent anatomic abnormalities are relatively non-specific and insensitive for making the diagnosis. 17,21 …”

Section: Introductionmentioning

confidence: 99%

MRI-Apparent Localized Deformation of the Median Nerve Within the Carpal Tunnel During Functional Hand Loading

et al. 2013

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In MR images, the median nerve of carpal tunnel syndrome (CTS) patients frequently appears flatter than in healthy subjects. The purpose of this work was to develop a metric to quantify localized median nerve deformation rather than global nerve flattening, the hypothesis being that localized median nerve deformation would be elevated in CTS patients. Twelve patients with CTS and 12 matched normals underwent MRI scanning in eight isometrically loaded hand conditions. 2D cross sections of the proximal and distal tunnel were analyzed for nerve cross sectional area, flattening ratio, and a position shift to the dorsal side of the tunnel. Additionally, new metrics based on the angulation of the nerve perimeter in 0.5-mm lengths around the boundary were calculated. The localized deformation metrics were able to detect differences between CTS patients and healthy subjects that could not be appreciated from the flattening ratio. During most hand activities, normal subjects had a higher average percentage of locally deformed nerve boundary than did CTS patients, despite having a rounder overall shape. Less local nerve deformation in the CTS patient group resulting from its interaction with flexor tendons suggests that the nerve may be less compliant in CTS patients.

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Section: Introductionmentioning

confidence: 99%

MRI-Apparent Localized Deformation of the Median Nerve Within the Carpal Tunnel During Functional Hand Loading

et al. 2013

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“…This has included identifying particular MRI-apparent characteristics that are frequently seen in CTS patients (nerve enlargement, nerve flattening, volar TCL bowing, and increased nerve signal intensity), and qualitative documentation and comparisons of median nerve location within the carpal tunnel (Allmann et al 1997; Girgis and Epstein 2000; Howe et al 1994; Mesgarzadeh et al 1989b; Middleton et al 1987; Shafer-Crane et al 2005). However, such MRI-apparent characteristics have proven to be rather insensitive and non-specific for diagnosing CTS (Radack et al 1997; Steinbach and Smith 2000).…”

Section: Discussionmentioning

confidence: 99%

Day-to-day variability of median nerve location within the carpal tunnel

Goetz

Thedens

Kunze

et al. 2010

Clinical Biomechanics

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Background Carpal tunnel syndrome is a commonly encountered entrapment disorder resulting from mechanical insult to the median nerve. MRI-based investigations have documented typical locations of the median nerve within the carpal tunnel; however, it is unclear whether those locations are consistent within an individual on different days. Methods To determine the day-to-day variability of nerve location, 3.0T MRI scans were acquired from six normal volunteers over multiple sessions on three different days. Half of the scans were acquired with the wrist in neutral flexion and the fingers extended, and the other half were acquired with the wrist in 35 degrees of flexion and the fingers flexed. Prior to half of the scans (in both poses), subjects performed a preconditioning routine consisting of specified hand activities and several repetitions of wrist flexion/extension. The shape, orientation, location, and location radius of variability of the median nerve and three selected flexor tendons were determined for each subject and compared between days. Findings Two of the six subjects had substantial variability in nerve location when the wrist was in neutral, and four of the subjects had high variability in nerve position when the wrist was flexed. Nerve variability was typically larger than tendon variability. The preconditioning routine did not decrease nerve or tendon location variability in either the neutral or the flexed wrist positions. Interpretation The high mobility and potential for large variability in median nerve location within the carpal tunnel needs to be borne in mind when interpreting MR images of nerve location.

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“…Another limitation to this study lies in the evaluation of shape measures made using the axial section plane of the MR sections. Normal carpal tunnel anatomy is conventionally imaged using axial sections taken through the wrist, 2,8,9,23 but this does not ensure that a given section is necessarily perpendicular to the tendons or to the nerve. Therefore, future work with this methodology should include a transformation to ensure that cross-sectional shape measures that are being compared are true cross sections through the 3D structure, rather than oblique sections through the structures as they happen to rest in the axial plane of the MRI scanner.…”

Section: Discussionmentioning

confidence: 99%

“…2 In these types of structure/shape studies, four main features have been identified that are commonly associated with carpal tunnel syndrome: enlargement of the median nerve, flattening of the median nerve, bulging of the transverse carpal ligament, and increased signal intensity of the median nerve on T2-weighted images. 3,9 Occasional attempts have been made to stage the severity of CTS based on progressive changes of these key criteria. 10 In such studies, the ratio of the volume of the carpal tunnel contents to the total carpal tunnel volume has also been a parameter of interest, as a greater ratio would indicate either a smaller tunnel or enlarged tunnel tissues.…”

Section: Introductionmentioning

confidence: 99%

“…17 Diagnosis of CTS based on changes in nerve MR signal intensity can also be confounded by the fact that nerve signal intensity may either increase or decrease relative to normal, depending on the severity of CTS symptoms. 10 Therefore, the primary diagnostic modalities employed to identify CTS have been physical examination and electrodiagnostic nerve conduction tests, with MRI examination reserved for cases where the diagnosis is either unclear 9,18 or confounded by additional pathology. 9,16 MRI presumably could play a greater diagnostic role if the pertinent anatomical abnormalities evident on MR images were more definitively linked to CTS pathology.…”

Section: Introductionmentioning

confidence: 99%

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Individual flexor tendon identification within the carpal tunnel: A semi-automated analysis method for serial cross-section magnetic resonance images

Kunze

Goetz

Thedens³

et al. 2009

ORR

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Carpal tunnel syndrome is commonly viewed as resulting from chronic mechanical insult of the median nerve by adjacent anatomical structures. Both the median nerve and its surrounding soft tissue structures are well visualized on magnetic resonance (MR) images of the wrist and hand. Addressing nerve damage from impingement of flexor digitorum tendons co-occupying the tunnel is attractive, but to date has been restricted by a lack of means for making individual identifications of the respective tendons. In this image analysis work, we have developed a region-growing method to positively identify each individual digital flexor tendon within the carpal tunnel by tracking it from a more distal MR section where the respective tendon identities are unambiguous. Illustratively, the new method was applied to MRI scans from four different subjects in a variety of hand poses. Conventional shape measures yielded less discriminatory information than did evaluations of individual tendon location and arrangement. This new method of rapid identification of individual tendons will facilitate analysis of tendon/nerve interactions within the tunnel, thereby providing better information about mechanical insult of the median nerve.

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Magnetic resonance imaging of the hand and wrist

Cited by 14 publications

References 40 publications

MRI-Apparent Localized Deformation of the Median Nerve Within the Carpal Tunnel During Functional Hand Loading

MRI-Apparent Localized Deformation of the Median Nerve Within the Carpal Tunnel During Functional Hand Loading

Day-to-day variability of median nerve location within the carpal tunnel

Individual flexor tendon identification within the carpal tunnel: A semi-automated analysis method for serial cross-section magnetic resonance images

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