Incidental findings associated with magnetic resonance imaging of the brachial plexus.

OBJECTIVE: The identification and management of incidental findings is becoming increasingly problematic, particularly in relation to brachial plexus imaging because the prevalence is unknown. Therefore, we aimed to estimate the prevalence of incidental findings in symptomatic patients undergoing MRI of the brachial plexus. METHODS: This retrospective cohort study included all children and adults who underwent MRI over a 12-year period, in a tertiary care centre in the UK. An incidental finding was any abnormality which was not a direct injury to or disease-process of the brachial plexus. An "incidentaloma" was defined by the need for further investigation or treatment. Multivariable logistic regression was used to estimate the odds ratio (OR) of an "incidentaloma". To estimate which factors were associated with the incident rate ratio (IRR) of incidental findings, multivariable Poisson regression was used. RESULTS: Overall, 502 scans (72%) reported incidental anomalies. Although the number of MRIs performed per annum increased by 23%, the prevalence of "incidentalomas" remained static (p = 0.766). Musculoskeletal incidental findings were the most prevalent (63%) and when identified, there were a median of 3 incidental anomalies per patient. Overall, 125 (18%) anomalies were "incidentalomas" which required further investigation or treatment. The odds of having further investigation or treatment was strongly related to the frequency of incidental findings [adjusted OR 1.16 (95% CI 1.08, 1.24)] and when a tumour was identified [adjusted OR 2.86 (95% CI 1.81, 4.53)]. The number of incidental findings recorded per scan increased when trainees co-reported with consultants [adjusted IRR 0.36 (95% CI 0.05, 0.67)] and in the presence of a tumour [adjusted IRR 0.39 (95% CI 0.28, 0.49)]. CONCLUSIONS: The prevalence of clinically important incidental findings on brachial plexus MRI is lower than organ-specific imaging, but still 18% of scans identified an 'incidentaloma' which required further investigation or treatment. ADVANCES IN KNOWLEDGE: This cohort study shows that approximately 1 in 5 symptomatic patients undergoing a brachial plexus MRI had a clinically important incidental findings, which required further investigation or treatment. This information can be used to inform patients consenting to clinical or research imaging.

Diffusion Tensor Imaging for Diagnosing Root Avulsions in Traumatic Adult Brachial Plexus Injuries: A Proof-of-Concept Study.

Cross-sectional MRI has modest diagnostic accuracy for diagnosing traumatic brachial plexus root avulsions. Consequently, patients either undergo major exploratory surgery or months of surveillance to determine if and what nerve reconstruction is needed. This study aimed to develop a diffusion tensor imaging (DTI) protocol at 3 Tesla to visualize normal roots and identify traumatic root avulsions of the brachial plexus. Seven healthy adults and 12 adults with known (operatively explored) unilateral traumatic brachial plexus root avulsions were scanned. DTI was acquired using a single-shot echo-planar imaging sequence at 3 Tesla. The brachial plexus was visualized by deterministic tractography. Fractional anisotropy (FA) and mean diffusivity (MD) were calculated for injured and avulsed roots in the lateral recesses of the vertebral foramen. Compared to healthy nerves roots, the FA of avulsed nerve roots was lower (mean difference 0.1 [95% CI 0.07, 0.13]; p < 0.001) and the MD was greater (mean difference 0.32 × 10-3 mm2/s [95% CI 0.11, 0.53]; p < 0.001). Deterministic tractography reconstructed both normal roots and root avulsions of the brachial plexus; the negative-predictive value for at least one root avulsion was 100% (95% CI 78, 100). Therefore, DTI might help visualize both normal and injured roots of the brachial plexus aided by tractography. The precision of this technique and how it relates to neural microstructure will be further investigated in a prospective diagnostic accuracy study of patients with acute brachial plexus injuries.

MRI for Detecting Root Avulsions in Traumatic Adult Brachial Plexus Injuries: A Systematic Review and Meta-Analysis of Diagnostic Accuracy.

Background Traumatic brachial plexus injuries affect 1% of patients involved in major trauma. MRI is the best test for traumatic brachial plexus injuries, although its ability to differentiate root avulsions (which require urgent reconstructive surgery) from other types of nerve injury remains unknown. Purpose To evaluate the accuracy of MRI for diagnosing root avulsions in adults with traumatic brachial plexus injuries. Materials and Methods For this systematic review, MEDLINE and Embase were searched from inception to August 20, 2018. Studies of adults with traumatic nonpenetrating unilateral brachial plexus injuries were included. The target condition was root avulsion. The index test was preoperative MRI, and the reference standard was surgical exploration. A bivariate meta-analysis was used to estimate summary sensitivities and specificities of MRI for avulsion. Results Eleven studies of 275 adults (mean age, 27 years; 229 men) performed between 1992 and 2016 were included. Most participants had been injured in motorcycle collisions (84%). All studies were at risk of bias, and there were high applicability concerns for the index test (ie, MRI) in four studies given the lack of diagnostic criteria, inadequate descriptions of pulse sequences, and multiplicity of reporting radiologists. Overall, 72% of patients with brachial plexus injuries had at least one root avulsion (interquartile range [IQR]: 53%-86%); meta-analysis of patient-level data was not performed because of sparse and heterogeneous data. With the nerve root as the unit of analysis, 583 of 918 roots were avulsed (median, 55%; IQR: 38%-71%); the mean sensitivity of MRI for root avulsion was 93% (95% confidence interval [CI]: 77%, 98%) with a mean specificity of 72% (95% CI: 42%, 90%). Conclusion On the basis of limited data, MRI offers modest diagnostic accuracy for traumatic brachial plexus root avulsion(s), and early surgical exploration should remain as the preferred method of diagnosis. Published under a CC BY 4.0 license. Online supplemental material is available for this article.

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 .

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.

MRI appearances of the femur following bone graft harvesting using the Reamer-Irrigator-Aspirator.

The reamer-irrigator-aspirator is increasingly being used to harvest autologous bone graft from the femur. The purpose of this study was to investigate the extent of neo-vascularisation and new bone formation that occurs within the medulla following the procedure, and determine if new bone formation would potentially allow a repeat bone harvest in those individuals subsequently requiring further bone graft. Eleven patients who had undergone femoral bone harvest were examined with MRI. The nature of the tissue within the medulla and the extent of neo-vascularisation were assessed. MRI was performed between 3 months and 28 months following bone graft harvest, mean 14 months. Intense vascularisation of the endostial cortical surface and neo-vascularisation of the haematoma within the canal occurred as soon as 3 months following bone harvest. From as early as 14 months the tissue was replaced by normal intramedullary bone. The formation of new bone within the medullary canal gives the potential for a repeat reaming, should further bone graft be required at a later date.

The postoperative spine.

Potential complications following spinal surgery include neural compression due to hematoma, recurrent disk herniation, epidural fibrosis, dural tear with pseudomeningocele formation, and infection. Specific complications relate to the use of spinal instrumentation that include incorrectly positioned instrumentation and failure of spinal fusion leading to instrumentation loosening or breakage. To interpret the postoperative imaging correctly, it is necessary to understand the nature of the surgical procedure that has been performed and the normal postoperative appearances. Magnetic resonance imaging is the mainstay in the evaluation of the postoperative spine. Radiographs and computed tomography continue to have a major role in assessing fusion and in the assessment of complications related to instrumentation.

The diagnostic accuracy of radiographs in Lisfranc injury and the potential value of a craniocaudal projection.

OBJECTIVE: The purpose of this study is to determine the diagnostic accuracy of radiographs in the diagnosis of Lisfranc injury. In addition, a foot phantom was investigated to determine the optimum degree of craniocaudal angulation on the anteroposterior radiograph to best show the joint. The angle of the joint in patients with midfoot injury was investigated to determine the optimum degree of craniocaudal angulation. MATERIALS AND METHODS: Sixty patients examined by CT had their radiographs evaluated independently and by consensus opinion by two observers, and the diagnostic performance was calculated using CT as the reference standard. A foot phantom was radiographed with varying degrees of craniocaudal angulation, and the radiograph that best revealed the joint was determined. This was compared with the angle of the joint as measured on CT. The angle of the joint in all 60 patients was measured on CT. RESULTS: The radiographs correctly identified 31 of the 45 cases (68.9%) of Lisfranc injury, with a positive predictive value of 84.4%, a negative predictive value of 53.3%, a sensitivity of 84.4%, and a specificity of 53.3%. Twenty degrees of craniocaudal angulation best showed the second tarsal-metatarsal joint of the phantom, and this correlated with a 20° angle measured by CT. The mean (± SD) angle of the joint in the patients was 28.9° ± 5.7°. CONCLUSION: Conventional radiographs miss a significant number of cases of Lisfranc injury. Craniocaudal angulation can better show the joint, and an angle of 28.9° is likely to optimally visualize the joint in the majority of patients.

Unilateral spondylolysis and the presence of facet joint tropism.

STUDY DESIGN: Retrospective review of the CT scans performed in a group of patients examined for a possible spondylolysis. OBJECTIVE: To investigate whether there is an association between unilateral spondylolysis and facet joint tropism. SUMMARY OF BACKGROUND DATA: Spondylolysis is a fatigue fracture of the pars interarticularis of great importance in sports injury. The demonstration of a unilateral spondylolysis is important because there is a potential for full healing if the athletic activity is modified, whereas bilateral spondylolysis frequently leads to established nonunion. Coronally orientated facet joints are known to predispose to spondylolysis by increasing the point loading of the pars interarticularis. The importance of this finding has not been investigated in unilateral spondylolysis. METHODS: A review of patients with low back pain and a possible diagnosis of spondylolysis who were investigated with multislice CT was performed. The coronal orientation of the facet joints at L4/5 and L5/S1 was measured and comparison was done between those with and without a spondylolysis. RESULTS: The coronal angle of 140 facet joints in 35 patients was recorded. Of 35 patients, 23 had a spondylolysis which was unilateral in 12 patients. The facet joint angle was significantly more coronally orientated in the presence of a spondylolysis when compared with an intact pars (means, 53° and 43°, respectively; P < 0.01). In the presence of a unilateral spondylolysis, the facet joint was significantly more coronally orientated on the side of the spondylolysis (means, 52° and 45°, respectively; P < 0.01). CONCLUSION.: This study is the first investigation of facet joint anatomy in unilateral spondylolysis. Asymmetric facet joints do increase the force through one side of the spine, with a unilateral spondylolysis occurring on the side of the more coronally orientated facet joint.

F-18 FDG PET/CT can help differentiate SAPHO syndrome from suspected metastatic bone disease.

A 20-year-old woman underwent magnetic resonance imaging of the spine for back pain, which demonstrated a solitary lesion in the T2 vertebral body suspicious for a metastasis. Subsequent computed tomography and bone scintigraphy identified several further sites of bony involvement but no primary malignancy. The patient was referred for F-18 FDG PET/CT which demonstrated intense FDG activity in the sternoclavicular and sacroiliac joints, in addition to the known thoracic vertebral body involvement suggesting spondyloarthropathy rather than malignant disease. During the course of investigations, the patient developed palmoplantar pustulosis leading to a diagnosis of SAPHO syndrome.