Magnetic resonance neurography of median neuropathies proximal to the carpal tunnel

Electrophysiology and Magnetic Resonance Neurography Findings of Nontraumatic Ulnar Mononeuropathy From a Tertiary Care Center

BACKGROUND

Ulnar nerve is frequently involved in mononeuropathies of the upper limb. Ulnar neuropathies have been diagnosed conventionally using clinical and electrophysiological findings. Physicians opt for nerve imaging in patients with ambiguous electrophysiological tests to gain additional information, identify etiology and plan management.

OBJECTIVES

The aim of this study was to describe the electrophysiological and the magnetic resonance neurography (MRN) findings in patients with nontraumatic ulnar neuropathy.

METHODS

All consecutive patients with suspected nontraumatic ulnar mononeuropathy were recruited; clinical assessment and electrophysiological studies (EPSs) were done in all. After EPS, patients with localization of lesion along the ulnar nerve underwent MRN.

RESULTS

All 39 patients recruited had clinical findings suggestive of ulnar neuropathy; Electrophysiological confirmation was possible in 36/39 (92.30%) patients. Localization of ulnar nerve lesion to elbow and wrist was possible in 27 (75%) and 9 (25%) patients, respectively. MRN was done in 22 patients; a lesion was identified in 19 of 22 (86.36%) ulnar nerves studied. Thickening and hyperintensity in T2 W/short TI inversion recovery images of ulnar nerve at the level of olecranon, suggesting ulnar neuropathy at elbow, was the commonest (8/22) imaging finding.

CONCLUSIONS

MRN acts as a complimentary tool to EPS for evaluating nontraumatic ulnar neuropathy. By identifying the etiology, MRN is likely to modify the management decision.

Magnetic Resonance Neurography for Evaluation of Peripheral Nerves

Peripheral nerve injuries (PNIs) continue to present both diagnostic and treatment challenges. While nerve transections are typically a straightforward diagnosis, other types of PNIs, such as chronic or traumatic nerve compression, may be more difficult to evaluate due to their varied presentation and limitations of current diagnostic tools. As a result, diagnosis may be delayed, and these patients may go on to develop progressive symptoms, impeding normal activity. In the past, PNIs were diagnosed by history and clinical examination alone or techniques that raised concerns regarding accuracy, invasiveness, or operator dependency. Magnetic resonance neurography (MRN) has been increasingly utilized in clinical settings due to its ability to visualize complex nerve structures along their entire pathway and distinguish nerves from surrounding vasculature and tissue in a noninvasive manner. In this review, we discuss the clinical applications of MRN in the diagnosis, as well as pre- and postsurgical assessments of patients with peripheral neuropathies.

Diagnostic accuracy of history taking, physical examination and imaging for non-chronic finger, hand and wrist ligament and tendon injuries: a systematic review update

OBJECTIVE

The diagnostic work-up for ligament and tendon injuries of the finger, hand and wrist consists of history taking, physical examination and imaging if needed, but the supporting evidence is limited. The main purpose of this study was to systematically update the literature for studies on the diagnostic accuracy of tests for detecting non-chronic ligament and tendon injuries of the finger, hand and wrist.

METHODS

Medline, Embase, Cochrane Library, Web of Science, Google Scholar ProQuest and Cinahl were searched from 2000 up to 6 February 2019 for identifying studies. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 checklist, and sensitivity (Se), specificity (Sp), accuracy, positive predictive value (PPV) and negative predictive value (NPV) were extracted.

RESULTS

None of the studies involved history taking. Physical examination, for diagnosing lesions of the triangular fibrocartilage complex (TFCC), showed Se, Sp, accuracy, PPV and NPV ranging from 58% to 90%, 20% to 69%, 56% to 73%, 53% to 71% and 55% to 65%, respectively. Physical examination in hand and finger injuries the Se, Sp, accuracy, PPV and NPV ranged from 88% to 99%, 75% to 100%, 34% to 88%, 91% to 100% and 75% to 95%, respectively. The accuracy of MRI with high-resolution (3 T) techniques for TFCC and interosseous ligaments of the proximal carpal row ranged from 89% to 91% and 75% to 100%, respectively. The accuracy of MRI with low-resolution (1.5 T) techniques for TFCC and interosseous ligaments of the proximal carpal row ranged from 81% to 100% and 67% to 95%, respectively.

CONCLUSIONS

There is limited evidence on the diagnostic accuracy of history taking and physical examination for non-chronic finger, hand and wrist ligament and tendon injuries. Although some imaging modalities seemed to be acceptable for the diagnosis of ligament and tendon injuries in the wrist in patients presenting to secondary care, there is no evidence-based advise possible for the diagnosis of non-chronic finger, hand or wrist ligament and tendon injuries in primary care.

Cross-sectional area of the median nerve at the wrist: Comparison of sonographic, MRI, and cadaveric measurements

BACKGROUND

This study compares median nerve cross-sectional area (CSA) measurements at the wrist obtained with ultrasound (US) and magnetic resonance imaging (MRI) using cadaveric measurements as the gold standard.

METHODS

Median nerve CSA was measured using US and MRI in 9 cadaveric wrists obtained from 5 subjects at 5 locations: distal forearm, proximal to tunnel inlet, at tunnel inlet, at tunnel outlet, and distal to tunnel outlet and then on identical cadaveric transverse sections obtained with a bandsaw. All US, MRI, and cadaveric measurements were repeated to determine reliability. Median nerves of 10 patients with clinical carpal tunnel syndrome (CTS) were measured with US and MRI using an identical method US.

RESULTS

Median nerve CSA MRI measurements correlated better (Pearson correlation: 0.80-0.95, P < .05) with cadaveric measurements than with US measurements (Pearson correlation: 0.61-0.79, P < .05). Median nerve CSA US measurements (8.6-12.5 mm² , P < .05) were smaller at all levels than MRI (11.3-14.7 mm² ) or cadaveric (11.0-14.9 mm² ) measurements while MRI and cadaver measurements were similar at all levels. Median nerve CSA MRI measurements in CTS patients were larger than US measurements at all levels.

CONCLUSION

Median nerve CSA measurements by MRI are larger than US measurements and correlated better with cadaveric measurements. Median nerve CSA criteria used for diagnosing CTS on US are not likely to be applicable to MRI.

Granular cell tumor of the ulnar nerve: MR neurography characterization

The authors report an unusual case of ulnar neuropathy caused by granular cell tumor. The report describes the anatomic 3 Tesla MR Neurography and functional diffusion tensor findings of the case, which was subsequently confirmed on surgical excision and histopathology.

Spectrum of superficial nerve-related tumor and tumor-like lesions: MRI features

Superficial soft-tissue masses arising from skin appendages, metastasis, and inflammatory lesions have been widely reported. However, nerve-related superficial mass-like lesions other than peripheral nerve sheath tumors are less commonly described. High resolution magnetic resonance imaging (MRI) is an excellent non-invasive tool for the evaluation of such lesions. In this article, the authors discuss the entire spectrum of these lesions and also outline a systemic diagnostic approach.