Diagnostic accuracy of MRI in adults with suspect brachial plexus lesions: a multicentre retrospective study with surgical findings and clinical follow-up as reference standard

Postprocedural Brachial Neuritis: Clinical, Electrodiagnostic, and Neuroimaging Features

BACKGROUND AND PURPOSE

Brachial neuritis is a monophasic condition affecting the brachial plexus and its branches, manifesting as acute shoulder and upper arm pain, followed by weakness and paresthesias. It can be triggered by antecedent events, including procedures such as surgery. Misdiagnosis and delay in diagnosis are common. Imaging is important to confirm the diagnosis of postprocedural brachial neuritis and exclude other etiologies.

MATERIALS AND METHODS

Clinical, electrodiagnostic, and neuroimaging features of patients with postprocedural brachial neuritis from a single quaternary care institution were identified and analyzed.

RESULTS

Six patients (2 women) were identified with a median age of 62 (range 49-70) years. Antecedent procedures included 4 cervical spine surgeries, 1 rotator cuff repair, and 1 central venous catheter placement. Time to symptom onset ranged from 1 day to 2 weeks. The initial symptom for 5 of the 6 patients was severe upper extremity pain followed by weakness. All patients had electrodiagnostic tests and MR neurography consistent with brachial neuritis. MR neurogram showed plexus and/or terminal branch abnormalities with associated muscular denervation edema. The C5 or C6 root and/or upper trunk were always involved. The most common branches affected were the suprascapular, long thoracic, and axillary nerves. Hourglass constrictions (HGCs) of these nerves were seen in 3 of 6 patients. The average time to diagnosis was 3.4 (range 1.5-5) months.

CONCLUSIONS

Postprocedural brachial neuritis is an under-recognized cause of acute upper extremity pain and weakness. MR neurography can exclude iatrogenic causes and document the presence of HGCs in affected nerves. Diagnostic neuroradiologists should be aware of this clinical entity and associated neuroimaging findings.

Pronator syndrome and anterior interosseous nerve palsy due to neurolymphomatosis: a case report

Pronator syndrome is a median nerve entrapment neuropathy that can be difficult to diagnose due to its variable presentation and objective findings. Neurolymphomatosis is an uncommon disease in which malignant lymphocytes infiltrate central or peripheral nerve endoneurium and is often missed for prolonged periods prior to diagnosis. We present a rare case of pronator syndrome and anterior interosseous nerve palsy due to neurolymphomatosis that was occult on initial MRI in spite of the presence of a median nerve mass discovered intra-operatively during neurolysis. This case demonstrates the value of ultrasound for the examination of peripheral nerve pathology and illustrates its utility as an adjunct to MRI, in part due to the ability to screen a large region.

The emerging role of MRI neurography in the diagnosis of chronic inguinal pain

INTRODUCTION

Chronic pain is a frequent and notable complication after inguinal hernia repair, it has been extensively studied, but its management and diagnosis are still difficult. The cause of chronic pain following inguinal hernia surgery is usually multifactorial. This case series highlights the utility of MRI neurography (MRN) in evaluating the damage to inguinal nerves after a hernia repair, with surgical confirmation of the preoperative imaging findings.

MATERIALS AND METHODS

A retrospective review was performed on patients who underwent inguinal mesh removal and triple denervation of the groin. Inclusion criteria included MRI neurography. All patients underwent surgical exploration of the inguinal canal for partial or complete mesh removal and triple denervation of the groin by the same senior surgeon.

RESULTS

A total of nine patients who underwent triple denervation were included in this case series. MRN was then performed on 100% of patients. The postoperative mean VAS score adjusted for all patients was 1.6 (SD p), resulting in a 7.5 score difference compared to the preoperative VAS score (p). Since chronic groin pain can be a severely debilitating condition, diagnosis, and treatment become imperative.

CONCLUSION

MRN can detect direct and indirect signs of neuropathy even in the absence of a detectable compressive cause aids in management and diagnosis by finding the precise site of injury, and grading nerve injury to aid pre-operative assessment for the nerve surgeon. Thus, it is a valuable diagnostic tool to help with the diagnosis of nerve injuries in the setting of post-inguinal hernia groin pain.

Correlation of Magnetic Resonance Imaging (Neurography) and Electrodiagnostic Study Findings with Intraoperative Findings in Post Traumatic Brachial Plexus Palsy

Background  The majority of brachial plexus injuries (BPIs) are caused by trauma; most commonly due to two-wheeler road accidents. It is important to determine whether the lesion in question is pre-ganglionic or post-ganglionic for purposes of surgical planning and prognosis. Diagnostic testing helps the surgeon to not only decide whether surgical intervention is required, but also in planning the procedure, thereby maximizing the patient's chances of early return to function. The aim of the study was to determine the diagnostic efficacy of electrodiagnostic studies (Edx) and magnetic resonance imaging (MRI) individually, and in unison, in detecting the type and site of BPI by comparison with intraoperative findings (which were used as the reference standard) in patients with posttraumatic BPI. Methods  It is an observational cross-sectional prospective randomized study, wherein 48 patients with BPI underwent a detailed clinical and neurological examination of the upper limb, Edx, MRI neurography and were subsequently operated upon. We assessed a total of 240 roots. The diagnosis of all spinal roots was noted on Edx. MRI was performed to look for root avulsion, pseudomeningocoele, and/or rupture injury. The patients were subsequently operated upon. All roots were traced from infraclavicular level right up to the foramen to ensure continuity of root or note rupture/ avulsion. The findings were tabulated. Results  MRI accurately diagnosed 138 of the 147 injured roots and MRI sensitivity for the detection of BPI was 93.88%, whereas Edx correctly identified 146 out of 147 injured roots and thus, had sensitivity of 99.32%; however, both lacked specificity (18.28 and 20.43%, respectively). With Edx and MRI in unison, sensitivity was 100% which meant that if a given patient with a BPI is subjected to both tests, not a single abnormal root will go unnoticed. Conclusion  Edx and MRI are two highly sensitive investigation modalities whose combined sensitivity is 100% for the detection of a root injury. Therefore, we recommend both tests as they are excellent screening tests.

Diagnostic Ability of Ultrasonography in Brachial Plexus Root Injury at Different Stages Post-trauma

Brachial plexus (BP) root injury often results in disability of the upper extremities. Improvements in high-frequency ultrasonography have enabled the visualization of BP nerve roots. This study was aimed at quantifying the diagnostic accuracy of ultrasonography in BP root injury at different stages post-trauma. A consecutive series of 170 patients with BP root injury between 2015 and 2019 were studied retrospectively and divided into three groups on the basis of time between injury and ultrasound examination (≤1 mo, 1-3 mo, >3 mo). Diagnosis of complete BP root injury under ultrasound was determined using a pre-defined criterion, including pseudomeningocele, retraction and rupture. Diagnostic accuracy was calculated based on surgical findings and intra-operative electrophysiological tests. Rates of detection of the cervical (C5-C8) and thoracic (T1) nerve roots under ultrasound were 99.4%, 99.4%, 99.4%, 95.9% and 79.4%, respectively. The sensitivity for complete BP root injury was 0.74, and the specificity was 0.91. No significant differences in sensitivity or specificity were observed across time stages. Ultrasound exhibited substantial consistency with surgical findings (κ = 0.70) for complete BP root injury at any stage post-injury. Ultrasound can be an optional method of diagnosis of complete BP root injury at an early stage post-injury.

Additive value of magnetic resonance neurography in diagnosis of brachial plexopathy: a cross-section descriptive study

Background

Management of brachial plexopathy requires proper localization of the site and nature of nerve injury. Nerve conduction studies and electrophysiological studies (ED) are crucial when diagnosing brachial neuropathy but these do not determine the actual site of the lesion. Conventional MRI has been used to evaluate the brachial plexus. Still, it carried the disadvantage of the inability to provide multi-planar images that depict the entire length of the neural plexus .It might be difficult to differentiate the brachial plexus nerves from adjacent vascular structures. Magnetic resonance neurography (MRN) is an innovative imaging technique for direct imaging of the spinal nerves. Our study aims to detect the additive role of MRN in the diagnosis of brachial plexopathy over ED. Forty cases of clinically suspected and proved by clinical examination and ED—traumatic (N = 30) and non-traumatic (N = 10)—were included in our study. We compared MRN finding with results of clinical examination and ED.

Results

MRN findings showed that the root was involved in 80% of cases, trunks in 70% of cases affecting the middle trunk in 40% of cases, the middle and posterior cord in 25%, lateral cord in 50%, and terminal branches on 10% of cases. Ten percent of cases were normal according to MRN, and 90% had abnormal findings in the form of preganglionic nerve root avulsion in 30% of cases, mild perineural edema surrounding C6/7 nerve roots in 20%, lower brachial trunk high signal in 10%, complicated with pseudo meningocele in 20%, and with increased shoulder muscle T2 signal intensity with muscle atrophy in 10%. There were minimal differences between clinical examination finding and MRN findings, with very good agreement between electromyography and nerve conduction (p value < 0.05, with sensitivity and specificity values of 94.44% and 100%, respectively).

Conclusion

MRN is important in differentiating different types of nerve injuries, nerve root avulsion, and nerve edema, playing an important role in differentiating the site of nerve injury, both preganglionic or postganglionic and planning for treatment of the cause of nerve injury, either medical or surgical.

The Evolving Landscape of Lung Cancer Surgical Resection: An Update for Radiologists With Focus on Key Chest CT Findings

Evolution of the multimodality management of early lung cancer, including progress in surgical techniques, has introduced the possibility of resection for lung cancer cases that historically were considered unresectable (e.g., select cases of T4 disease and oligometastatic disease). However, the TNM classification does not uniformly correlate with lung cancer operability and resectability. Radiologic evaluation is therefore critical in identifying patients' suitability to undergo lung cancer resection and in guiding the selection of a surgical approach from among a range of such approaches, including wedge resection, segmentectomy, lobectomy, bilobectomy, and pneumonectomy. The radiologist must understand the available surgical options, along with their advantages and disadvantages, and provide a report that includes critical information on tumor size, location, and extension and anatomic relations that may influence the surgical technique. Preoperative CT findings may also help predict expected postoperative lung function and the associated impact on the postoperative course of the patient. This article reviews the role of chest CT in the preoperative evaluation of lung cancer, focusing on the key CT findings that help direct surgical decision making in the context of an expanding range of patients who may be considered candidates for resection.

Ressonância magnética como método para diagnóstico das lesões traumáticas por avulsão do plexo braquial

Objective  The incidence of traumatic brachial plexus injuries has been increasing considerably in Brazil, mainly due to the increase in the number of motorcycle accidents. The aim of the present study is to evaluate the sensitivity and specificity of magnetic resonance imaging (MRI) in the diagnosis of brachial plexus avulsion lesions, comparing it with the findings of physical and intraoperative examination.

Methods  A total of 16 patients with brachial plexus injury were prospectively evaluated and treated at the hand surgery outpatient clinic from our service. All patients underwent MRI of the brachial plexus, and the findings were inserted on a table, as well as the physical examination data, and part of the patients had the plexus evaluated intraoperatively.

Results  In the present study, the accuracy of MRI in the identification of root avulsion was 100%, with 100% sensitivity and specificity when comparing imaging with surgical findings.

Conclusion Magnetic resonance imaging showed high sensitivity and specificity, confirmed by intraoperative findings, which allows considering this test as the gold standard in the diagnosis of avulsion in traumatic brachial plexus injuries.

ACR Appropriateness Criteria® Plexopathy: 2021 Update

Plexopathy may be caused by diverse pathologies, including trauma, nerve entrapment, neoplasm, inflammation, infection, autoimmune disease, hereditary disease, and idiopathic etiologies. For patients presenting with brachial or lumbosacral plexopathy, dedicated plexus MRI is the most appropriate initial imaging modality for all clinical scenarios and can identify processes both intrinsic and extrinsic to the nerves. Other imaging tests may be appropriate for initial imaging depending on the clinical scenario. This document addresses initial imaging strategies for brachial and lumbosacral plexopathy in the following clinical situations: nontraumatic plexopathy with no known malignancy, traumatic plexopathy (not perinatal), and plexopathy occurring in the context of a known malignancy or posttreatment syndrome. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Diagnostic Accuracy of the Magnetic Resonance Imaging in Adult Post-Ganglionic Brachial Plexus Traumatic Injuries: A Systematic Review and Meta-Analysis

BACKGROUND

Traumatic brachial plexus injuries are rare but serious consequences of major traumas. Pre-ganglionic lesions are considered irreparable, while post-ganglionic injuries can be potentially treated if an early diagnosis is available. Pre-surgical diagnosis is important to distinguish low-grade from high-grade lesions and to identify their location. The aim of the review is to evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) in the identification of adult post-ganglionic lesions due to traumatic brachial plexus injuries, compared to intraoperative findings.

METHODS

Research on the main scientific electronic databases was conducted. Studies of adults with traumatic post-ganglionic brachial plexus injuries were included. The index test was preoperative MRI and the reference standard was surgical exploration. Pooled sensitivity and specificity were calculated.

RESULTS

Four studies were included for the systematic review, of which three articles met the inclusion criteria for the meta-analysis. Pooled sensitivity and pooled specificity values resulted high. The sensitivity value is associated with a high heterogeneity index of the selected literature.

CONCLUSION

MRI can be considered, despite the limits, the gold standard exam in morphological evaluation of brachial plexus injuries, particularly in the diagnosis of post-ganglionic traumatic injuries.

Diagnostic accuracy of imaging studies for diagnosing root avulsions in post-traumatic upper brachial plexus traction injuries in adults

BACKGROUND

There is no consensus about which type of imaging study, computed tomography myelography (CTM) or magnetic resonance imaging (MRI), provides better information concerning root avulsion in adult brachial plexus injuries.

METHODS

Patients with upper brachial plexus traumatic injuries underwent both CTM and MRI and surgical exploration. The imaging studies were analyzed by two independent radiologists and the data were compared with the intraoperative findings. The statistical analysis was based on dichotomous classification of the nerve roots (normal or altered). The interobserver agreement was assessed using Cohen's Kappa. The accuracy of CTM and MRI in comparison with the intraoperative findings was evaluated using the same methodology.

RESULTS

Fifty-two adult patients were included. CTM tended to yield slightly higher percentages of alterations than MRI The interobserver agreement was better on CTM than on MRI for all nerve roots: C5, 0.9960 (strong) vs. 0.145 (poor); C6, 0.970 (strong) vs. 0.788 (substantial); C7, 0.969 (strong) vs. 0.848 (strong). The accuracy regarding the intraoperative findings was also higher on CTM (moderate, kappa 0.40-0.59) than on MRI (minimal, kappa 0.20-0.39) for all nerve roots. Accordingly, the overall percentage concordance (both normal or both altered) was superior in the CTM evaluation (approx. 70-75% vs. 60-65%). CTM was superior for both sensitivity and specificity at all nerve roots.

CONCLUSION

CTM had greater interobserver agreement and higher diagnostic accuracy than MRI in adult patients with root avulsions due to brachial plexus injury.

Diagnostic accuracy of MRI for traumatic adult brachial plexus injury: A comparison study with surgical findings

We studied the diagnostic accuracy of MRI in 35 adult patients with traumatic brachial plexus injury in comparison with intra operative findings. The overall sensitivity to detect root avulsions was 39% and specificity was 75%. MRI was more useful in the diagnosis of lower root avulsions. At trunk and division level injuries, the sensitivity was 87% but specificity was only 26%. It was not able to differentiate the type and extent of post-ganglionic injuries. The accuracy of pseudomeningocele as avulsion on surgical finding was 96% (27/28). Pseudomeningocele correlates well with root avulsions. Its presence warrants early referral and surgical exploration.

Multimodal magnetic resonance imaging of peripheral nerves: Establishment and validation of brachial and lumbosacral plexi measurements in 163 healthy subjects

PURPOSE

This study aims to provide normal reference values for quantitative parameters for brachial and lumbosacral plexi on multimodal MRI. In addition, the parameter variations between the left and right sides, the individual nerve groups, genders and age groups were also evaluated.

MATERIALS AND METHODS

Multimodal MRI was evaluated in 163 healthy subjects, who were randomly divided into three groups: brachial plexus, lumbosacral plexus and diffusion tensor imaging groups. Nerve diameters, contrast ratios, T2 nerve-muscle signal ratios (nT2), fractional anisotropy (FA) values and apparent diffusion coefficients (ADC) were measured in both plexi. Parametric tests and Pearson correlation for normally distributed data, and non-parametric tests and Spearman correlation for non-normally distributed data were used.

RESULTS

There were no significant differences in parameters between the left and right sides. The diameters of the C7, L4-S1, sciatic, and femoral nerve roots were larger in men than in women (P < 0.05). The nT2 in the brachial and lumbosacral plexi and the contrast ratio in the lumbosacral plexus were significantly higher in the elderly. The diameter of the S1 nerve root was smaller in the elderly. There were no significant differences between the individual nerve groups in contrast ratios and in brachial plexus nT2. A gradual increase in the nT2 from the top to the bottom was observed in the L4-S1 nerve roots (P < 0.05).

CONCLUSION

This study provides multi-parameter normative data for the brachial and lumbosacral plexi while considering differences between the two sides, the individual nerves, genders, and the ages.

Degree of Agreement between Electrodiagnostic Testing and Magnetic Resonance Imaging in the Evaluation of Brachial Plexopathy

OBJECTIVE

Electrodiagnostic study (EDX) and magnetic resonance imaging (MRI) are commonly used in the diagnosis of brachial plexopathy, but the agreement between these 2 studies is unknown. The aim of this study was to evaluate the agreement of EDX and MRI in patients with brachial plexopathy.

DESIGN

The records of 69 patients with symptoms of brachial plexopathy who underwent EDX and MRI were reviewed. Based on the degree of agreement of EDX and MRI results, patients were classified as a "complete match," "partial match," or "mismatch."

RESULTS

Both studies yielded similar results for the majority of patients (63.2%). Among the enrolled patients, 26.4% were classified as a "complete match," 36.8% as "partial match," and 36.8% as "mismatch." However, only 1 test, either EDX or MRI, revealed abnormal findings in 21.1% of patients.

CONCLUSIONS

The agreement between EDX and MRI was high in patients with brachial plexopathy. However, only one of these tests, not both, revealed abnormal findings in several cases. Although both EDX and MRI were in accord with the diagnosis of brachial plexopathy in majority of cases, these 2 studies remain complementary diagnostic modalities for evaluating brachial plexopathies.

Diffusion Tensor Imaging of the Brachial Plexus: A Comparison between Readout-segmented and Conventional Single-shot Echo-planar Imaging

Purpose:

Diffusion tensor imaging (DTI) adds functional information to morphological magnetic resonance neurography (MRN) in the assessment of the brachial nerve plexus. To determine the most appropriate pulse sequence in scan times suited for diagnostic imaging in clinical routine, we compared image quality between simultaneous multi-slice readout-segmented (rs-DTI) and conventional single-shot (ss-DTI) echo-planar imaging techniques.

Methods:

Institutional Review Board (IRB) approved study including 10 healthy volunteers. The supraclavicular brachial plexus, covering the nerve roots and trunks from C5 to C7, was imaged on both sides with rs-DTI and ss-DTI. Both sequences were acquired in scan times <7 min with b-values of 900 s/mm² and with isotropic spatial resolution.

Results:

In rs-DTI image, the overall quality was significantly better and distortion artifacts were significantly lower (P = 0.001–0.002 and P = 0.001–0.002, respectively) for both readers. In ss-DTI, a trend toward lower degree of ghosting and motion artifacts was elicited (reader 1, P = 0.121; reader 2, P = 0.264). No significant differences between the two DTI techniques were found for signal-to-noise ratios (SNR), contrast-to-noise ratios (CNR) and fractional anisotropy (FA) (P ≥ 0.475, P ≥ 0.624, and P ≥ 0.169, respectively). Interreader agreement for all examined parameters and all sequences ranged from intraclass correlation coefficient (ICC) 0.064 to 0.905 and Kappa 0.40 to 0.851.

Conclusion:

Incomparable acquisition times rs-DTI showed higher image quality and less distortion artifacts than ss-DTI. The trend toward a higher degree of ghosting and motion artifacts in rs-DTI did not deteriorate image quality to a significant degree. Thus, rs-DTI should be considered for functional MRN of the brachial plexus.

Shear Wave and Strain Elastographic Features of the Brachial Plexus in Healthy Adults: Reliability of the Findings-a Pilot Study

OBJECTIVES

To determine the sonoelastographic findings for the normal brachial plexus via shear wave elastography (SWE) and strain elastography (SE) and the reliability of the measurements.

METHODS

Thirty-nine healthy adult volunteers were included in the study. The brachial plexus was evaluated with SWE and SE at the interscalene region by 2 observers separately, and the observers were unaware of each other's outcomes. The elastic modulus (kilopascals), shear wave velocity (SWV, meters per second), and strain ratio were obtained. Elasticity patterns on SE were assessed as hard, intermediate, and soft. An intraclass correlation coefficient analysis was performed for determining the reliability of sonoelastographic findings. The correlation of sonoelastographic features with age and sex was investigated.

RESULTS

The volunteers included 13 men and 26 women. The mean age of the participants ± SD was 36.2 ± 7.8 (range, 25-56) years. The mean elasticity modulus values of the brachial plexus for observers 1 and 2 were 17.03 (95% confidence interval [CI], 15.03, 19.03) and 13.83 (95% CI, 12.23, 15.43) kPa, respectively; the SWVs were 2.24 (95% CI, 2.12, 2.36) and 2.04 (95% CI, 1.93, 2.15) m/s; and the strain ratios were 1.20 (95% CI, 1.18, 1.25) 1.38 (95% CI, 1.22, 1.54). The elasticity pattern was mostly intermediate stiffness for both observers (n = 72 [92.3%]; n = 75 [96.1%]). The intraclass correlation coefficient was poor to moderate and statistically significant for the elastic modulus, SWV, and elasticity pattern (P < .05 for all parameters). The sonoelastographic characteristics of the brachial plexus had no correlation with age or sex.

CONCLUSIONS

The reliability and reproducibility of sonoelastography of the brachial plexus are low, and the appropriateness of this technique in this manner is controversial.

Brachial Plexus Ultrasound and MRI in Children with Brachial Plexus Birth Injury

BACKGROUND AND PURPOSE

Brachial plexus birth injury is caused by traction on the neck during delivery and results in flaccid palsy of an upper extremity commonly involving C5-C6 nerve roots. MR imaging and MR myelography help to assess the anatomic location, extent, and severity of brachial plexus injuries which influence the long-term prognosis along with the surgical decision making. Recently, sonography has been increasingly used as the imaging modality of choice for brachial plexus injuries. The aim of this study was to assess the degree of correlation among brachial plexus sonography, MR imaging, and surgical findings in children with brachial plexus birth injury.

MATERIALS AND METHODS

This prospective study included 55 consecutive patients (girls/boys = 32:23; mean age, 2.1 ± 0.8 months) with brachial plexus birth injury between May 2014 and April 2017. The patients were classified according to the Narakas classification and were followed up at 4- to 6-week intervals for recovery by the Modified Mallet system and sonography without specific preparation for evaluation. All patients had MR imaging under general anesthesia. Nerve root avulsion-retraction, pseudomeningocele, and periscalene soft tissue were accepted brachial plexus injury findings on imaging. Interobserver agreement for MR imaging and the agreement between imaging and surgical findings were estimated using the κ statistic. The diagnostic accuracy of sonography and MR imaging was calculated on the basis of the standard reference, which was the surgical findings.

RESULTS

Forty-three patients had pre- and postganglionic injury, 12 had only postganglionic injury findings, and 47% of patients underwent an operation. On sonography, no patients had preganglionic injury, but all patients had postganglionic injury findings. For postganglionic injury, the concordance rates between imaging and the surgical findings ranged from 84% to 100%, and the diagnostic accuracy of sonography and MR imaging was 89% and 100%, respectively. For preganglionic injury, the diagnostic accuracy of MR imaging was 92%. Interobserver agreement and the agreement between imaging and the surgical findings were almost perfect for postganglionic injury (κ = 0.81-1, P < .001).

CONCLUSIONS

High-resolution sonography can identify and locate the postganglionic injury associated with the upper and middle trunks. The ability of sonography to evaluate pre- and the postganglionic injury associated with the lower trunk was quite limited. Sonography can be used as a complement to MR imaging; thus, the duration of the MR imaging examination and the need for sedation can be reduced by sonography.

Magnetic resonance imaging for detecting root avulsions in traumatic adult brachial plexus injuries: protocol for a systematic review of diagnostic accuracy

BACKGROUND

Adult brachial plexus injuries (BPI) are becoming more common. The reconstruction and prognosis of pre-ganglionic injuries (root avulsions) are different to other types of BPI injury. Preoperative magnetic resonance imaging (MRI) is being used to identify root avulsions, but the evidence from studies of its diagnostic accuracy are conflicting. Therefore, a systematic review is needed to address uncertainty about the accuracy of MRI and to guide future research.

METHODS

We will conduct a systematic search of electronic databases alongside reference tracking. We will include studies of adults with traumatic BPI which report the accuracy of preoperative MRI (index test) against surgical exploration of the roots of the brachial plexus (reference standard) for detecting either of the two target conditions (any root avulsion or any pseudomeningocoele as a surrogate marker of root avulsion). We will exclude case reports, articles considering bilateral injuries and studies where the number of true positives, false positives, false negatives and true negatives cannot be derived. The methodological quality of the included studies will be assessed using a tailored version of the QUADAS-2 tool. Where possible, a bivariate model will be used for meta-analysis to obtain summary sensitivities and specificities for both target conditions. We will investigate heterogeneity in the performance of MRI according to field strength and the risk of bias if data permits.

DISCUSSION

This review will summarise the current diagnostic accuracy of MRI for adult BPI, identify shortcomings and gaps in the literature and so help to guide future research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016049702 .

Magnetic Resonance Neurography in Chronic Lumbosacral and Pelvic Pain: Diagnostic and Management Impact-Institutional Audit

BACKGROUND/OBJECTIVE

Low back and pelvic pain are among the most prevalent conditions worldwide, with major social and economic costs. The aim of this study was to evaluate the role of magnetic resonance neurography (MRN) of lumbosacral plexus in the management and outcomes of these patients with chronic pain.

METHODS

Consecutive patients with chronic lumbosacral and pelvic pain referred for MRN over a year were included. Preimaging and postimaging clinical diagnosis and treatment, pain levels, and location were recorded. Pain-free survival was compared between treatments using a Cox proportional hazards model.

RESULTS

A total of 202 patients with mean age 53.7 ± 14.8 years and a male/female ratio of 1:1.53 were included. Of these patients, 115 presented with radiculopathy (57%), 56 with pelvic pain (28%), and 31 with groin pain (15%). Mean initial pain level was 6.9 ± 1.9. Mean symptom duration was 4.21 ± 5.86 years. Of these patients, 143 (71%) had a change in management because of MRN. After MRN, reduction in pain levels was observed in 21 of 32 patients receiving conservative treatment (66%), 42 of 67 receiving injections (63%), and 27 of 33 receiving surgery (82%). Follow-ups were available in 131 patients. Median pain-free survival was 12 months. Patients treated with surgery had significantly lower pain recurrence than patients receiving other treatments in the same time frame (hazard ratio, 3.6; 95% confidence interval, 1.4-9.2; P = 0.0061).

CONCLUSIONS

MRN use in chronic lumbosacral and pelvic pain led to a meaningful change in diagnosis and treatment. After MRN, conservative treatment and injections provided pain relief; however, patients benefited more from surgery than from any other treatment.

ACR Appropriateness Criteria® Plexopathy

MRI without and with contrast is the most accurate imaging method to determine whether a process is intrinsic or extrinsic to a nerve of the brachial or lumbosacral plexus. However, there are no Current Procedural Terminology codes to correspond to imaging studies of the brachial or lumbar plexus discretely. This assessment uses "MRI of the brachial plexus" or "MRI of the lumbosacral plexus" as independent entities given that imaging acquisition for the respective plexus differs in sequences and planes compared with those of a routine neck, chest, spine, or pelvic MRI, yet acknowledges the potential variability of ordering practices across institutions. In patients unable to undergo MRI, CT offers the next highest level of anatomic evaluation. In oncologic patients, PET/CT imaging can identify the extent of tumor involvement and be beneficial to differentiate radiation plexitis from tumor recurrence but provides limited resolution of the plexus itself. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The diagnostic accuracy of 1.5T magnetic resonance imaging for detecting root avulsions in traumatic adult brachial plexus injuries

Identification of root avulsions is of critical importance in traumatic brachial plexus injuries because it alters the reconstruction and prognosis. Pre-operative magnetic resonance imaging is gaining popularity, but there is limited and conflicting data on its diagnostic accuracy for root avulsion. This cohort study describes consecutive patients requiring brachial plexus exploration following trauma between 2008 and 2016. The index test was magnetic resonance imaging at 1.5 Tesla and the reference test was operative exploration of the supraclavicular plexus. Complete data from 29 males was available. The diagnostic accuracy of magnetic resonance imaging for root avulsion(s) of C5-T1 was 79%. The diagnostic accuracy of a pseudomeningocoele as a surrogate marker of root avulsion(s) of C5-T1 was 68%. We conclude that pseudomeningocoles were not a reliable sign of root avulsion and magnetic resonance imaging has modest diagnostic accuracy for root avulsions in the context of adult traumatic brachial plexus injuries.

LEVEL OF EVIDENCE

III.

Magnetic Resonance Neurographic and Clinical Long-Term Results After Oberlin's Transfer for Adult Brachial Plexus Injuries

The primary goal of the surgical treatment of upper brachial plexus injuries is to restore active elbow flexion. Accordingly, Oberlin's transfer has been frequently performed since 1994 and has influenced the development of other nerve transfers. However, the window of opportunity for nerve transfers remains a subject of controversy. The objective of this study was to assess magnetic resonance (MR) neurographic, clinical and electrophysiological long-term results after Oberlin's transfer. For this purpose, we performed a retrospective follow-up study. Six patients with upper brachial plexus or musculocutaneous nerve injuries were assessed; 2 were iatrogenic nerve injuries following shoulder arthroscopy or neurofibroma resection. Direct and indirect signs of neuropathy were objectified with MR neurography. Moreover, clinical and electrodiagnostic follow-up was performed and all patients completed the Disabilities of Arm, Shoulder and Hand score. Mean follow-up was 48 ± 21.9 (range, 20-73) months. Mean age was 40 ± 11.3 years and mean delay to surgery was 9 ± 3.2 months. All patients were satisfied with the functional results and the median Disabilities of Arm, Shoulder and Hand score was 21 (range, 1-57). Biceps strength was improved in 5 patients from Medical Research Council grade M0 to M4-5 and in one patient to M2-3. The donor nerve showed normal motor and sensory action potentials. Follow-up MR neurography demonstrated biceps reinnervation. Taken together, this study reports good long-term results after Oberlin's transfer. MR neurography represents an excellent, noninvasive preoperative planning tool and can be of high value in selected postoperative cases. The combined evaluation of nerves and muscles may help to indicate nerve transfers in delayed cases.

Radiological clinical trials: Proposal of a problem-finding questionnaire to improve study success

AIM

To develop a survey to help define the main problems in radiological clinical trials.

METHODS

Since 2006, we have managed seven different radiological clinical trials recruiting patients in academic and non-academic centres. We developed a preliminary questionnaire using a four-round Delphi approach to identify problems occurring in radiological clinical trials run at our centre. We investigated the recruitment experience, involvement of all multi-disciplinary team members and main obstacles to completing the projects. A final round of Delphi processes elucidated solutions to the identified problems.

RESULTS

Among 19/20 (95%) respondents, 10 (53%) were young physicians (under 35 years old), and the respondents included non-faculty members, fellows, residents, and undergraduate students. Ninety-four percent (18/19) of respondents showed interest in conducting clinical trials. On a scale of 1 to 10, the problems with higher/worse scores (8-9) were related to technical or communication problems. The most frequent problems across all studies were technical problems related to clinical trial equipment, insufficient willingness to participate, obstacles to understanding the design of electronic-case report form and extra work.

CONCLUSION

The developed questionnaire identified the main recurring problems in radiological clinical trials as perceived by end-users and helped define possible solutions that are mostly related to having dedicated clinical trial research staff.

Usefulness of IDEAL T2 imaging for homogeneous fat suppression and reducing susceptibility artefacts in brachial plexus MRI at 3.0 T

PURPOSE

To quantitatively and qualitatively compare fat-suppressed MR imaging quality using iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) with that using frequency-selective fat-suppressed (FSFS) T2 images of the brachial plexus at 3.0 T.

MATERIALS AND METHODS

Prospective MR image analysis was performed in 40 volunteers and 40 patients at a single centre. Oblique-sagittal and coronal IDEAL fat-suppressed T2 images and FSFS T2 images were compared. Visual assessment was performed by two independent musculoskeletal radiologists with respect to: (1) susceptibility artefacts around the neck, (2) homogeneity of fat suppression, (3) image sharpness and (4) tissue resolution contrast of pathologies. The signal-to-noise ratios (SNR) for each image sequence were assessed.

RESULTS

Compared to FSFS sequences, IDEAL fat-suppressed T2 images significantly reduced artefacts around the brachial plexus and significantly improved homogeneous fat suppression (p < 0.05). IDEAL significantly improved sharpness and lesion-to-tissue contrast (p < 0.05). The mean SNRs were significantly improved on T2-weighted IDEAL images (p < 0.05).

CONCLUSION

IDEAL technique improved image quality by reducing artefacts around the brachial plexus while maintaining a high SNR and provided superior homogeneous fat suppression than FSFS sequences.

Accuracy of MRI in diagnosing peripheral nerve disease: a systematic review of the literature

OBJECTIVE

MRI is increasingly being used to evaluate extracranial peripheral nerve disease in clinical practice. The objective of this study was to systematically review the accuracy of MRI in distinguishing normal from abnormal extracranial peripheral nerves.

CONCLUSION

There is significant heterogeneity between studies investigating the accuracy of MRI. Studies have shown that nerve T2-weighted or STIR hyperintensity, nerve enlargement, and nerve flattening are associated with peripheral nerve disease.

Brachial plexus injuries: diagnosis performance and reliability of everyday tools

PURPOSE

Determining the patterns of brachial plexus injuries is challenging. Diagnostic methods have been used to facilitate diagnosis, but there is no consensus regarding which tool best complements physical examination (PE). Magnetic resonance imaging (MRI) and nerve conduction studies (NCSs) are instruments with widespread use and feasibility for everyday assessment. In this study, we evaluated the diagnostic performance of these diagnostic instruments and PE. We also assessed the agreement in the PE and diagnostic instrument findings of two experienced and certified hand surgeons.

METHODS

We reviewed data gathered from medical records and compared these data with the results of operative findings. We divided data according to the site of injury and the root injury patterns for all three diagnostic instruments (PE, MRI, and NCSs).

RESULTS

We considered 102 assessments. We found poor inter-observer agreement for the PE assessments and poor agreement among the PE, NCS, and MRI assessments. Diagnostic performance was higher for PE: sensitivity = 97.8 [95% confidence interval (C.I.) = 92.1-99.7]; specificity = 30.8 [95% C.I. = 9.1-61.4], and NCSs (sensitivity = 98.9 [95% C.I. = 93.9-100]; specificity = 23.1 [95% C.I. = 5-53.8]. MRI had inferior performance for all measurements. Separate analysis using pre- and post-ganglionic injuries revealed that PE had the lowest sensitivity, 46.7 (95% C.I. = 21.3-73.4) despite having the highest specificity, 81.6 (95% C.I. = 71.9-89.1).

DISCUSSION

Low agreement among the findings using different diagnostic instruments demonstrated that PE is the most specific tool, despite its low sensitivity. Detailed PE is cornerstone for evaluating brachial plexus injuries and NCSs are better than MRI for scrutinizing injuries not found in PE.

CLINICAL RELEVANCE

In our study, NCSs exhibited superior performance to MRI, and should be considered a more reliable supporting tool after detailed PE.

Fascicular ratio: a new parameter to evaluate peripheral nerve pathology on magnetic resonance imaging: a feasibility study on a 3T MRI system

The objective of the study was to define and quantitatively evaluate the fascicular ratio (FR) on magnetic resonance imaging (MRI) in patients with peripheral neuropathies compared with healthy controls. Forty control subjects (20 women, 20 men; age, 44.6 ± 13.4 years) and 40 patients with peripheral neuropathy (22 women, 18 men; age, 50.3 ± 10.2 years) were examined with a standard 3T MRI protocol. With customized software (with semiautomatic and automatic interface), the hypointense and hyperintense areas of the peripheral nerves corresponding to fascicular and nonfascicular tissue were examined on T1-weighted sequences. The ratio of fascicular pixels to total pixels was called FR. Correlation with FR calculated on high-resolution ultrasound was performed. The statistical analysis included the Mann-Whitney U test of controls versus patients, the receiver operating characteristic (ROC) analysis, and the subgroup analysis of patients according to etiologies of neuropathy. Intraobserver and interobserver agreement was calculated based on the evaluation made by 3 readers. Finally, a complete automatic evaluation was performed. On MRI, FRs were significantly increased in patients compared with controls (FR, 76.7 ± 15.1 vs 56 ± 12.3; P < 0.0001 for the semiautomatic interface; and FR 66.3 ± 17.5 vs 47.8 ± 18.4; P < 0.0001 for the automatic interface). The increase in FR was caused mainly by an increase in the hypointense part of the nerve. This observation was valid for all causes of neuropathies. ROC analysis found an area under the curve of 0.75 (95% confidence interval, 0.44-0.81) for FR to discriminate neuropathy from control. The correlation coefficient between MRI and ultrasound was significant (r = 0.49; 95% confidence interval for r, 0.21-0.70; P = 0.012). With the semiautomated evaluation, the mean intraobserver agreement was good (K = 0.86). The interobserver agreements were also good (reader 1 vs reader 2, k = 0.71; reader 2 vs reader 3, k = 0.78; reader 3 vs reader 1, k = 0.71). There were no statistically significant differences between the results obtained using the 2 methods. FR calculation on MRI is feasible, and it may be used in adjunct to standard MRI evaluation in peripheral nerve disorders.