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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. [ABSTRACT FROM AUTHOR]

Lesion location is an important determinant for post-stroke cognitive impairment. Although several ‘strategic’ brain regions have previously been identified, a comprehensive map of strategic brain regions for post-stroke cognitive impairment is lacking due to limitations in sample size and methodology. We aimed to determine strategic brain regions for post-stroke cognitive impairment by applying multivariate lesion-symptom mapping in a large cohort of 410 acute ischemic stroke patients. Montreal Cognitive Assessment at three to six months after stroke was used to assess global cognitive functioning and cognitive domains (memory, language, attention, executive and visuospatial function). The relation between infarct location and cognition was assessed in multivariate analyses at the voxel-level and the level of regions of interest using support vector regression. These two assumption-free analyses consistently identified the left angular gyrus, left basal ganglia structures and the white matter around the left basal ganglia as strategic structures for global cognitive impairment after stroke. A strategic network involving several overlapping and domain-specific cortical and subcortical structures was identified for each of the cognitive domains. Future studies should aim to develop even more comprehensive infarct location-based models for post-stroke cognitive impairment through multicenter studies including thousands of patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: The objective of this study is to evaluate the effects of the Multi-disciplinary Orthopaedics Rehabilitation Empowerment (MORE) Program on reducing chronic disability among injured workers and improving efficiency of work rehabilitation process. METHODS:A cohort of patients with workplace injuries in the lower back were recruited from orthopaedics clinics and assigned to either MORE group (n = 139) or control group (n = 106). Patients in MORE group received an early MRI screening and a coordinated multi-disciplinary management, while patients in the control group received conventional care. Outcome variables are time to return-to-work (RTW) from date of injury, waiting time for MRI screening and time to medical assessment board (MAB). RESULTS: Patients in the MORE Program had significantly shorter duration for RTW (MORE: 6.1 months, Control: 12.8 months, p < 0.01), and more RTW cases (n = 64, 46.0%) compared to Control group (n = 29, 27.4%). The MORE group also had much shorter waiting time for MRI scans (91.85 vs. 309.2 days, p <0.001) and MAB referral after MRI scans (97.2 vs. 178.9 days, p = 0.001) compared to Control group. CONCLUSIONS: The MORE Program which emphasizes early intervention and early MRI screening, is shown to be effective in shortening sick leave and improving RTW outcomes of injured workers. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the morphologic changes of aldosterone-producing adenoma (APA) on computed tomography (CT) before and after radiofrequency ablation (RFA) and to assess the factors that are important in determining successful complete ablation of these tumours. Method: Between August 2004 and August 2011, 24 consecutive patients with APA undergoing CT-guided percutaneous RFA were identified from our prospective database. The pre-RFA and post-RFA CT appearances of these APAs that showed positive biochemical response were reviewed retrospectively for their 3-dimensional size, tumour volume, and CT attenuation in terms of Hounsfield units (HU). A comparison of these parameters before and after RFA was performed. Results: In this study, there were 23 APAs in these 24 patients that showed biochemical cure of primary aldosteronism after RFA. When comparing post-RFA to pre-RFA CTs, there was no significant change in tumour size (14.5 mm vs 14.6 mm: P = .83) and tumour volume (1.55 cm3 vs 1.59 cm3; P =.41) after RFA. In nonenhanced CT images, there was no significant reduction in HU from pre-RFA to post-RFA measurements (4.4 HU vs 7.9 HU; P = .52). In contrast-enhanced CTs, there was a significant drop in HU after RFA (from 48.3 HU to 14.7 HU; P = .03). None of the included cases showed a focal region of contrast enhancement to suggest residual tumour. Conclusion: A change in tumour size, tumour volume, and HU in nonenhanced CT were unreliable in defining radiologic treatment success. Only changes in HU in contrast-enhanced CT was useful in confirming a positive treatment response after RFA for APA. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this prospective, randomized study was to compare the performance of a rotator interval approach with the posterior glenohumeral approach for ultrasound-guided contrast injection prior to MR shoulder arthrography., Method: This study was approved by the institutional review board. One hundred and twenty consecutive patients referred for MR shoulder arthrography were randomized into four groups: rotator interval approach in-plane (n = 30); rotator interval approach out-of-plane (n = 30); posterior approach in-plane (n = 30); and posterior approach out-of plane (n = 30). Outcome measures included procedure time, number of injection attempts, patient-reported pain score (0-10), and radiologist-reported technical difficulty (0-10). MR arthrograms were assessed for adequacy of joint distension, diagnostic utility, and extra-capsular contrast leakage., Results: All 120 patients had a successful ultrasound-guided injection with adequate joint distension and diagnostic utility for MR arthrography. In-plane needle guidance was less technically demanding, quicker, required fewer injection attempts, and had a lower frequency of contrast leakage than out-of-plane needle guidance. The posterior glenohumeral approach was less technically demanding though had a higher frequency of contrast leakage and caused more patient discomfort than the rotator interval approach., Conclusion: For ultrasound-guided shoulder joint injection, an in-plane approach is preferable. The posterior glenohumeral approach is less technically demanding though causes more patients discomfort than the rotator interval approach possibly due to the longer needle path., (Copyright © 2020. Published by Elsevier Inc.)

Objective: The purpose of this study was to assess the effects of traction during MR arthrography of the wrist on joint space widening, cartilage visibility, and detection of tears of the triangular fibrocartilage complex (TFCC) and intrinsic ligaments., Subjects and Methods: A prospective study included 40 wrists in 39 patients (25 men, 14 women; mean age, 35 years). MR arthrography was performed with a 3-T MRI system with and without axial traction. Two radiologists independently measured wrist and carpal joint space widths and semiquantitatively graded articular cartilage visibility. Using conventional arthrography as the reference standard and working in consensus, they assessed for the presence of tears of the TFCC, lunotriquetral ligament (LTL), and scapholunate ligament (SLL). Visibility of a tear before traction was compared with visibility after traction., Results: With traction, all joint spaces in the wrist and carpus were significantly widened (change, 0.15-1.01 mm; all p < 0.006). Subjective cartilage visibility of all joint spaces improved after traction (all p ≤ 0.048) except for that of the radioscaphoid space, which was well visualized even before traction. Conventional arthrography depicted 24 TFCC tears, seven LTL tears, and three SLL tears. The accuracy of tear detection improved after traction for the TFCC (98% after traction vs 83% before traction), the LTL (100% vs 88%), and the SLL (100% vs 95%). Tear visibility improved after traction for 54% of TFCC tears, 71% of LTL tears, and 66% of SLL tears., Conclusion: Wrist MR arthrography with axial traction significantly improved the visibility of articular cartilage and the detection and visibility of tears of the TFCC and intrinsic ligaments. The results favor more widespread use of traction during MR arthrography of the wrist.

Objective: Standard percutaneous bone biopsy involves manual needle insertion. Recently, a battery-powered needle drilling biopsy system (OnControl) has been introduced. We report our experience using this drill biopsy system for CT-guided percutaneous bone biopsy in 25 patients., Conclusion: CT-guided percutaneous biopsy using the OnControl bone access system is a safe, quick, and effective method for sampling bone lesions visible on CT.

Background: Pathological fracture is an uncommon presentation in patients with long bone osteosarcoma., Procedures: We retrospectively reviewed the database of all patients with histologically proven osteosarcoma under the age of 18 years from 1991 to 2011 in a tertiary pediatric oncology referral center. Five patients with pathological fractures as the first presentation of osteosarcoma were identified. The treatment strategies and complications were evaluated. Ten sex-, age-, and site- matched osteosarcoma patients without pathological fracture were selected as controls. The incidence of distant metastases and outcome, including local recurrence and survival, were compared between the index (with pathological fracture) and the control (without pathological fracture) groups., Results: In the index group, all five patients were boys and the mean age of onset was 13.1 years (range 9.2-14.9). Three patients (60%, 3/5) received amputation and two (40%) had wide local excision of the tumor. Pathological fracture group showed higher rate of lung (60% vs. 10%, P = 0.04) and bone (60% vs. 10%, P = 0.04) metastases at presentation, and shorter overall 5-year survival (P = 0.04) than the control group. There was no significant difference of local recurrence (20%, P = 1.00) between these two groups regardless of the type of operation., Conclusion: Osteosarcoma complicated by pathological fracture as first presentation had higher incidence of lung and bone metastases at presentation and worse survival rate when compared with patients without pathological fracture., (Copyright © 2012 Wiley Periodicals, Inc.)

Background: An occult pneumothorax (OP) is a pneumothorax not seen on a supine chest X-ray (CXR) but detected on abdominal or thoracic computed tomography (CT) scanning. With the increasing use of CT in the management of significantly injured trauma patients, more OPs are being detected. The aim of this study was to classify OPs diagnosed on thoracic CT (TCT) and correlate them with their clinical significance., Methods: Retrospective analysis of prospectively collected trauma registry data. Total 36 (N=36) consecutive significantly injured trauma patients admitted through the emergency department (ED) who sustained blunt chest trauma and underwent TCT between 1 January 2007 and 31 December 2008 were included. OP was defined as the identification (by a consultant radiologist) of a pneumothorax on TCT that had not been detected on supine CXR. OPs were classified by laterality (unilateral/bilateral) and location (apical, basal, non apical/basal). The size of pneumothoraces, severity of injury [including number of associated thoracic injuries and injury severity score (ISS)], length of hospital stay and mortality were compared between groups. The need for tube thoracostomy and clinical outcome were also analysed., Results: Patients with bilateral OPs (N=8) had significantly more associated thoracic injuries (median: 2 vs. 1, p=0.01), higher ISS (median: 35 vs. 23, p=0.02) and longer hospital stay (median: 20 days vs. 11 days, p=0.01) than those with a unilateral OP (N=28). Basal OPs (N=7) were significantly larger than apical (N=10) and non-apical/basal Ops (N=11). Basal OPs were associated with significantly more associated thoracic injuries (median: 2 vs. 1, p=0.01), higher ISS (median: 35 vs. 25, p=0.04) and longer hospital stays (median: 23 days vs. 17 days, p=0.02) than apical Ops, which had higher ISS (median: 35 vs. 25, p=0.04) and longer hospital stays (median: 23 days vs. 15 days, p=0.02) than non-apical/basal OPs. Non-apical/basal OPs were associated with more related injuries (median: 2 vs. 1, p=0.02) than apical OPs. All apical and non-apical/basal OPs were successfully managed expectantly without associated mortality., Conclusion: This TCT classification of OP is proposed to help clinicians to decide on subsequent management of the OP. Basal OPs are significantly larger in size, and both basal and bilateral OPs are associated with higher severity of injury and longer hospital stay. These groups of patient may benefit from prophylactic tube thoracostomy instead of conservative treatment. On the other hand, apical and non-apical/basal groups is smaller in size, less severely injured and thus can be successfully managed expectantly., (Copyright © 2012 Elsevier Ltd. All rights reserved.)