Whole-body magnetic resonance neurography in patients with chronic inflammatory demyelinating polyneuropathy.

INTRODUCTION/AIMS: Whole-body magnetic resonance neurography (MRN) is an imaging modality that shows peripheral nerve signal change in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). We aimed to explore the diagnostic potential of whole-body MRN and its potential as a monitoring tool after immunotherapy in treatment-naïve CIDP patients. METHODS: Whole-body MRN using coronal 3-dimensional short tau inversion recovery (STIR) sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE) techniques was performed in patients being investigated for CIDP and in healthy controls. Baseline clinical neuropathy scales and electrophysiologic parameters were collected, and MRN findings were compared before and after CIDP treatment. RESULTS: We found highly concordant symmetrical thickening and increased T2 signal intensities in the brachial/lumbosacral plexus, femoral, or sciatic nerves in five of the eight patients with a final diagnosis of CIDP and none of the healthy controls. There were no treatment-related imaging changes in five patients with CIDP who completed a follow-up study. Diffuse, symmetrical thickening, and increased T2 signal in root, plexus, and peripheral nerves were found in two patients ultimately excluded due to a diagnosis of polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes (POEMS) syndrome in addition to signal changes in the muscles, bony lesions, organomegaly, and lymphadenopathy. DISCUSSION: Whole-body MRN imaging shows promise in detecting abnormalities in proximal nerve segments in patients with CIDP. Future studies evaluating the role of MRN in assessing treatment response should consider follow-up scans after treatment durations of more than 4 months.

Radiologic evaluation of ankle fracture malunions of the fibula.

Ankle fractures involving the distal fibula are common injuries. Malreductions and subsequent malunions of the distal fibula can result in worse clinical outcomes and posttraumatic arthritis. The ability to accurately evaluate and identify malreductions and malunions of the distal fibula is important. A number of different radiographic and CT measurements have been described to assess fibular length and rotation. This review highlights various radiologic measures and discusses their advantages and limitations.

Spectrum and patterns of shoulder pathology on MRI in symptomatic elite wheelchair basketball athletes.

BACKGROUND: Wheelchair basketball (WCB) is a popular para-sport adapted for athletes with physical disabilities. Shoulder injuries are commonly reported among WCB athletes. However, the understanding of the specific patterns and characteristics of shoulder injuries in WCB players is currently limited, and there is a lack of comprehensive literature available on this subject. OBJECTIVES: To investigate the spectrum of pathologies observed in elite wheelchair basketball (WCB) athletes referred for MRI evaluation of symptomatic injuries of the shoulder. METHODS: Retrospective review of consecutive elite WCB athletes referred for MRI evaluation of symptomatic shoulder injury. Demographic, clinical, and functional data including international wheelchair basketball federation (IWBF) classification of each athlete were collected. A total of 28 MRI studies were reviewed. Excluding MRI examinations of the same shoulder, 18 study cases were assessed for pathology of the rotator cuff (RC), labrum, long-head of biceps tendon, glenohumeral and acromioclavicular joints, and osseous lesions of the humerus or glenoid. Correlations between clinical-demographic features and MRI findings were statistically evaluated. RESULTS: Supraspinatus tears were observed in 72.2%, infraspinatus tears in 50%, and subscapularis tears in 38.9% shoulders. Articular-sided partial tears frequently involved posterior supraspinatus (88.9%) and anterior infraspinatus (100%). Labral tears were seen in 38.9%, with involvement of the posterosuperior labrum in all tears. Hill-Sachs and osseous Bankart lesions (5.6%), and anterior-inferior labral tears (11.1%), were uncommon findings. Statistically significant correlations were observed of low IWBF point class and non-ambulatory athletes with subscapularis tendinosis (p = 0.015, p = 0.001) and tearing (p = 0.050, p = 0.013), and athletes with limited trunk control with subscapularis tendinosis (p = 0.013). CONCLUSIONS: RC tears are common in elite WCB athletes with pattern of RC and labral tearing suggesting internal (superior-posterior) impingement as a contributory pathoetiologic mechanism. Non-ambulatory, low IWBF point class athletes, as well as those with limited trunk control have a statistically significant increase in subscapularis tendon pathology on MRI.

Imaging in an academic orthopedic shoulder service: a report on incidental lung pathology findings.

INTRODUCTION: Computed tomography (CT) is often utilized for both diagnostic and pre-operative planning purposes in shoulder arthroplasty. Our study reports on the incidence of pulmonary findings in our pre-operative shoulder arthroplasty population over 14 years at our institution. METHODS: We conducted a retrospective review of all "shoulder CT" exams ordered by two orthopedic upper extremity surgeons between the years of 2008 and 2021. These exams were then further analyzed to include only those ordered for the purpose of pre-operative "shoulder arthroplasty" planning. All incidental findings were documented and those with pulmonary findings were then further analyzed. A detailed chart review was then performed on these patients to determine the impact on their planned shoulder arthroplasty. RESULTS: A total of 363 shoulder pre-operative CTs were ordered by our two upper extremity orthopedic surgeons at our institution between the years of 2008 and 2021. Primary lung cancer in the form of adenocarcinoma (n = 3) had an incidence of 0.8% of all CT scans and 1.4% of all pulmonary incidental findings. Fifteen patients (4% of all CT scans and 7% of all pulmonary incidental findings) had no concern for malignancy and were appropriately evaluated with further imaging based on their initial shoulder CT. CONCLUSION: While shoulder arthroplasty and pre-operative planning with CT imaging continue to become more common, so too is the incidence of reported pulmonary findings. From a patient care standpoint, it is important that these findings are accurately identified, appropriately triaged, and communicated clearly to our patients.

T2-weighted MRI radiomics in high-grade intramedullary osteosarcoma: predictive accuracy in assessing histologic response to chemotherapy, overall survival, and disease-free survival.

OBJECTIVE: To analyze radiomic features obtained from pre-treatment T2-weighted MRI acquisitions in patients with histologically proven intramedullary high-grade osteosarcomas and assess the accuracy of radiomic modelling as predictive biomarker of tumor necrosis following neoadjuvant chemotherapy (NAC), overall survival (OS), and disease-free survival (DFS). MATERIALS AND METHODS: Pre-treatment MRI exams in 105 consecutive patients who underwent NAC and resection of high-grade intramedullary osteosarcoma were evaluated. Histologic necrosis following NAC, and clinical outcome-survival data was collected for each case. Radiomic features were extracted from segmentations performed by two readers, with poorly reproducible features excluded from further analysis. Cox proportional hazard model and Spearman correlation with multivariable modelling were used for assessing relationships of radiomics features with OS, DFS, and histologic tumor necrosis. RESULTS: Study included 74 males, 31 females (mean 32.5yrs, range 15-77 years). Histologic assessment of tumor necrosis following NAC was available in 104 cases, with good response (≥ 90% necrosis) in 41, and poor response in 63. Fifty-three of 105 patients were alive at follow-up (median 40 months, range: 2-213 months). Median OS was 89 months. Excluding 14 patients with metastases at presentation, median DFS was 19 months. Eleven radiomics features were employed in final radiomics model predicting histologic tumor necrosis (mean AUC 0.708 ± 0.046). Thirteen radiomic features were used in model predicting OS (mean concordance index 0.741 ± 0.011), and 12 features retained in predicting DFS (mean concordance index 0.745 ± 0.010). CONCLUSIONS: T2-weighted MRI radiomic models demonstrate promising results as potential prognostic biomarkers of prospective tumor response to neoadjuvant chemotherapy and prediction of clinical outcomes in conventional osteosarcoma.

Bone Tumors: Imaging Features of Common and Rare Benign Entities.

Benign primary bone tumors are far more common than their malignant counterpart and are encountered in everyday practice. Imaging plays a crucial role in recognition of the nonaggressive nature of these lesions, determining the need for further imaging or follow-up. This article reviews the clinical, demographic, and radiological features of some of the more common entities classified as benign or intermediate (locally aggressive) according to the World Health Organization classification of bone tumors.

The accuracy of routine knee MR imaging in detection of acute neurovascular injury following multiligamentous knee injury.

OBJECTIVE: To assess the accuracy of routine knee MRI in detecting acute popliteal artery and/or common peroneal nerve (CPN) dysfunction following multiligamentous knee injury (MLKI), with correlation of MRI findings to clinical outcome. MATERIALS AND METHODS: Routine MRI knee examinations in 115 MLKI patients (54/115 with acute neurovascular injury, 61/115 without neurovascular injury) were retrospectively reviewed. Cases were classified by injury mechanism and ligamentous injuries sustained. MRI examinations were reviewed by two readers for vascular (arterial flow void, arterial calibre, intimal flap, perivascular hematoma) and CPN (intraneural T2-hyperintensity, calibre, discontinuity, perineural hematoma) injuries. Accuracy of routine knee MRI in the diagnosis of acute neurovascular injury and correlation of MRI findings to clinical outcome were evaluated. RESULTS: Patients included 86/115 males, mean age 33 years. The accuracy of MRI in diagnosis of acute CPN injury was 80.6%, 83.6% (readers 1 and 2): sensitivity (78%, 79.7%), specificity (80%, 86.7%), PPV (78%, 82.5%), and NPV (82.7%, 84.4%). Increased intraneural T2 signal showed a significant correlation to acute CPN dysfunction (p < 0.05). MRI was 75%, 69.8% (readers 1 and 2) accurate in detecting acute vascular injury: sensitivity (73.3%, 86.7%), specificity (75.2%, 67.3%), PPV (30.5%, 36.1%), and NPV (95%, 97.1%). No MRI features of vascular injury showed a statistical correlation with clinical outcome. Neurovascular complications were more common in ultra-low-energy injuries and KD-V3L pattern of ligament disruption. CONCLUSION: Routine MRI is of limited accuracy in assessing vascular complication, but higher accuracy in assessing CPN injury following MLKI. Increased intraneural T2 signal on conventional knee MR imaging shows statistically significant association with clinically documented acute CPN dysfunction following MLKI.

Soft tissue solitary fibrous tumors of the musculoskeletal system: spectrum of MRI appearances and characteristic imaging features.

OBJECTIVE: Solitary fibrous tumors (SFTs) uncommonly occur in the musculoskeletal system, with limited available data on their MRI appearance. This study was performed to assess the MRI features of SFTs in the musculoskeletal system (MSK-SFTs). MATERIALS AND METHODS: Pre-treatment MRI in 39 patients with pathologically proven SFTs in the trunk or extremities was evaluated. Patient demographics, clinical management and follow-up, and lesion histology were reviewed. MRI features including lesion location, size, morphology, signal characteristics, vascularity, and relationship to major neurovascular structures were assessed. RESULTS: MSK-SFTs most frequently occurred in the lower extremity (23/39 cases, 59%), deep to fascia (29/39, 74%), and intermuscular (22/29, 76%) in location. The majority of deep lesions were located along a major neurovascular bundle (20/29, 69%). Lesions had well-defined margins (39/39, 100%), multilobulated contours (27/39, 69%), and measured mean 6.9 ± 2.8 cm. The majority of lesions had slightly hyperintense T1 signal (34/39, 87%) and heterogenous intermediate-to-high T2/STIR signal (28/38, 74%). A "pseudo-cerebriform" internal architectural pattern on fluid-sensitive sequences, with internal lobulations and low signal bands/septations, was observed in 63% (24/38) of lesions. Lesions commonly demonstrated prominent intra-lesional (30/39, 75%) and peripheral juxta-lesional flow voids. Local invasion of surrounding structures was uncommon (3/39, 8%). Mitotically active lesions (p = 0.02) and lesions with tumor necrosis (p < 0.01) were larger in size. Tumor necrosis was associated with T1 heterogeneity (p = 0.04). Distant metastasis occurred in 10% (4/39) of patients, all in mitotically active lesions pre-operatively considered at least at intermediate risk of metastasis. CONCLUSION: MSK-SFTs commonly present as well-defined, hypervascular masses deep to fascia along major neurovascular bundles, with heterogeneous slightly hyperintense T1 signal, intermediate-to-high T2/STIR signal, and prominent macroscopic flow voids.

Imaging features of gluteal in vitro fertilization injection granulomas, with delayed clinical presentation simulating soft tissue sarcoma.

OBJECTIVES: To review the clinical and imaging findings of patients with remote history of intramuscular (IM) in vitro fertilization (IVF) gluteal injections, presenting with signs and symptoms of a possible gluteal soft tissue sarcoma. METHODS AND METHODS: Retrospective review of consecutive patients with a history of prior IVF therapy referred for MRI evaluation of a gluteal soft tissue mass was performed. Six patients were reviewed, with 5 patients meeting study inclusion criteria. Imaging exams (ultrasound n = 3, MRI n = 5) were assessed for lesion location, morphology, and intrinsic imaging characteristics. One case proceeded to percutaneous biopsy with histopathologic correlation. RESULTS: Average patient age was 43 years (range 38-50). Mean time interval between IVF IM injections and MRI was 5.7 years (range 2.2-13 years). Clinical findings included palpable gluteal mass (5/5) and local pain (4/5). Ultrasound showed heterogeneous subcutaneous lesions with varying complex cystic/solid internal echogenicity. On MRI, each case illustrated an irregularly marginated lesion, mean maximal dimension 3.5 cm (range 1.5-5.9 cm), within the deep gluteal subcutaneous fat composed of solitary (1/5) or multifocal (4/5) lobules demonstrating internal areas of high T1 and homogeneous low T2 fat suppressed signal with surrounding peripheral reticular high T2 signal. Correlative histological assessment showed central areas with features of fat necrosis and a peripheral inflammatory rim. CONCLUSIONS: In the setting of prior IVF therapy, imaging features of an irregularly marginated, deep subcutaneous gluteal lesion with inflammatory soft tissue changes surrounding solitary or multifocal areas of loculated fat signal may be seen as an inflammatory response to previous inadvertent subcutaneous injection(s).

Preoperative Magnetic Resonance Imaging Accurately Detects the Arthroscopic Comma Sign in Subscapularis Tears.

PURPOSE: To assess the accuracy and reliability of routine preoperative magnetic resonance imaging (MRI) in the detection of the comma sign compared with the gold standard of arthroscopic findings. METHODS AND MATERIALS: Preoperative MRI exams in consecutive patients undergoing arthroscopic subscapularis tendon repair, over a 5-year time frame, were retrospectively reviewed for full-thickness tears of the subscapularis and supraspinatus tendons, fatty atrophy of the subscapularis and supraspinatus muscles, and status of the long head of the biceps tendon. Each case was also evaluated for presence or absence of a comma sign on MRI. Surgical findings served as the diagnostic standard of reference in determination of a comma sign. RESULTS: The study cohort included 45 male and 10 female patients (mean age, 56; range, 32-80 years). A comma sign was present at arthroscopy in 19 patients (34.5%). Interclass and intrarater correlation showed 100% agreement in preoperative assessment of a comma sign on MRI. MRI showed an overall accuracy of 83.6% in diagnosis of a comma sign (sensitivity, 63.2%; specificity, 94.4%; positive predictive value, 85.7%; negative predictive value, 82.9%; positive likelihood ratio, 11.37; negative likelihood ratio, 0.39). No statistically significant association was observed between an arthroscopic comma sign and patient demographics or MRI findings of full-thickness rotator cuff tears, muscle fatty atrophy, or long head of the biceps tendon pathology. CONCLUSIONS: MR imaging illustrates excellent reliability and good specificity and accuracy in detection of the arthroscopic comma sign in the setting of subscapularis tendon tearing. Detection of a comma sign on MRI may be important preoperative planning information in the arthroscopic management of patients with subscapularis tendon tears. LEVEL OF EVIDENCE: Level IV, retrospective diagnostic study.

Gluteus minimus tendon: MR imaging features and patterns of tendon tearing.

PURPOSE: To highlight the spectrum of pathology and patterns of gluteus minimus tendon tearing observed on MR imaging of the hip. METHODS AND MATERIALS: Retrospective review of consecutive hip MRI exams with findings of gluteus minimus tendon (GMin) pathology. A total of 194 exams in 178 patients (148 female, mean age 61) were reviewed. MRI exams are assessed for GMin: tendinopathy, partial, or complete tendon tears. GMin muscular fatty atrophy, enthesopathic cortical irregularities of the greater trochanter (GT), and peri-trochanteric edema or bursal fluid collections were assessed in all cases. In all cases of complete GMin tendon tearing, position and relationship of GMin tendon were assessed relative to its normal insertion site and adjacent soft tissues. RESULTS: Clinical indications for MR imaging included hip pain (n = 151), and weakness or altered gait (n = 13). Insertional GMin tendinopathy was seen in 72, partial tearing in 81, and complete tendon tearing in 40 cases. Complete tendon tearing without proximal retraction was observed in 38/40 cases with soft tissue continuity visualized between distal tendon fibers and the proximal vastus lateralis muscle. Peri-trochanteric bursal fluid (n = 61), osseous irregularities of the GT (n = 118), and fatty atrophy GMin (n = 102) were statistically associated with partial or complete GMin tendon tearing (p < 0.001). CONCLUSIONS: The spectrum of GMin tendon pathology observed on MR imaging ranges from tendinopathy to complete tears. The majority of complete distal GMin tendon tears from the greater trochanter show continuity of distal tendon fibers with the proximal vastus lateralis, distally tethering and limiting proximal tendon retraction.

Bone Marrow Mesenchymal Stromal Cell Treatment in Patients with Osteoarthritis Results in Overall Improvement in Pain and Symptoms and Reduces Synovial Inflammation.

Patients with late-stage Kellgren-Lawrence knee osteoarthritis received a single intra-articular injection of 1, 10, or 50 million bone marrow mesenchymal stromal cells (BM-MSCs) in a phase I/IIa trial to assess safety and efficacy using a broad toolset of analytical methods. Besides safety, outcomes included patient-reported outcome measures (PROMs): Knee Injury and Osteoarthritis Outcome Score (KOOS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC); contrast-enhanced magnetic resonance imaging (MRI) for cartilage morphology (Whole Organ MRI Scores [WORMS]), collagen content (T2 scores), and synovitis; and inflammation and cartilage turnover biomarkers, all over 12 months. BM-MSCs were characterized by a panel of anti-inflammatory markers to predict clinical efficacy. There were no serious adverse events, although four patients had minor, transient adverse events. There were significant overall improvements in KOOS pain, symptoms, quality of life, and WOMAC stiffness relative to baseline; the 50 million dose achieved clinically relevant improvements across most PROMs. WORMS and T2 scores did not change relative to baseline. However, cartilage catabolic biomarkers and MRI synovitis were significantly lower at higher doses. Pro-inflammatory monocytes/macrophages and interleukin 12 levels decreased in the synovial fluid after MSC injection. The panel of BM-MSC anti-inflammatory markers was strongly predictive of PROMs over 12 months. Autologous BM-MSCs are safe and result in significant improvements in PROMs at 12 months. Our analytical tools provide important insights into BM-MSC dosing and BM-MSC reduction of synovial inflammation and cartilage degradation and provide a highly predictive donor selection criterion that will be critical in translating MSC therapy for osteoarthritis. Stem Cells Translational Medicine 2019;8:746&757.

Imaging of the Postoperative Condition of Posterolateral Corner Injuries.

Posterolateral corner (PLC) injuries of the knee are often sustained in combination with anterior or posterior cruciate ligament injuries. A variety of surgical techniques including acute repair, nonanatomical reconstructions, and anatomical reconstructions have been used to treat grade III PLC injuries. Scant literature is available on postoperative imaging of the PLC. This article reviews the more commonly used surgical techniques and the postoperative imaging assessment of the PLC of the knee.

The Dorsal 4-finger Technique: A Novel Method to Examine Metacarpophalangeal Joints in Patients with Rheumatoid Arthritis.

OBJECTIVE: To describe the dorsal 4-finger technique (DFFT) in examining metacarpophalangeal (MCP) joints of patients with rheumatoid arthritis (RA) and compare it to the traditional 2-finger technique (TFT) using ultrasound (US) as a gold standard. METHODS: Four rheumatologists evaluated 180 MCP joints of 18 patients with RA. All patients underwent US for greyscale (GSUS) and power Doppler US (PDUS). Agreements between rheumatologists, the 2 techniques, and US were evaluated using Cohen κ and the first-order agreement coefficient (AC1) κ methods. RESULTS: The population comprised 17 females (94.4%) with a mean (SD) age and disease duration of 56.8 (14.4) and 21.8 (12.9) years, respectively. Eight patients (44.4%) were taking methotrexate monotherapy, while 10 patients (55.6%) were receiving biologics. US evaluation revealed 69 (38.3%) and 30 (16.7%) joints exhibited synovitis grade 2-3 by GSUS and PDUS, respectively. Effusion was documented in 30 joints (16.7%). The mean intraobserver agreement using the DFFT and TFT were 80.5% and 86%, respectively. The mean interobserver agreements using the DFFT and TFT were 84% and 74%, respectively. κ agreement with US findings was similar for both techniques in tender joints but was higher for the DFFT in nontender joints (0.33 vs 0.07, p = 0.015 for GSUS) and (0.48 vs 0.11, p = 0.002 for PDUS). The DFFT had a higher sensitivity in detecting ballottement by GSUS (0.47 vs 0.2, p < 0.001) and PDUS (0.60 vs 0.27, p < 0.001). CONCLUSION: The DFFT is a novel, reproducible, and reliable method to examine MCP joints, and it has a better correlation with US than the traditional TFT.

Accuracy of non-arthrographic 3T MR imaging in evaluation of intra-articular pathology of the hip in femoroacetabular impingement.

OBJECTIVE: To investigate the accuracy of non-arthrographic 3-T MRI compared to hip arthroscopy in the assessment of labral and cartilaginous pathology in patients with suspected FAI. MATERIALS AND METHODS: Following IRB approval and waived consent, 42 consecutive cases of suspected FAI with non-arthrographic 3-T MRI and arthroscopy of the hip were reviewed. High-resolution TSE MR imaging was evaluated in consensus by two musculoskeletal radiologists, blinded to arthroscopic findings, for the presence of labral tears and articular cartilage lesions. Acetabular cartilage was categorized as normal, degeneration/fissuring, delamination, or denudation. MRI findings were compared to arthroscopy. Sensitivity, specificity, accuracy, and predictive values for MRI were calculated using arthroscopy as the standard of reference. RESULTS: Forty-two hips in 38 patients with a mean age of 29 (range 13-45 years) were assessed. Mean interval between MRI and arthroscopy was 154 days (range 27-472 days). MRI depicted 41 cases with labral tears (sensitivity 100%, specificity 50%, accuracy 98%, PPV 98%, NPV 100%), 11 cases with femoral cartilage abnormalities (sensitivity 85%, specificity 100%, accuracy 95%, PPV 100%, NPV 94%), and 36 cases with acetabular cartilage lesions (sensitivity 94% specificity 67%, accuracy 90%, PPV 94%, NPV 67%). Of the 36 cases with acetabular cartilage lesions on MRI, 7 were characterized as degeneration/fissuring, 26 as delamination, and 3 as denudation, with discordant results between MRI and arthroscopy for grading of articular cartilage in ten cases. CONCLUSION: Non-arthrographic 3-T MR imaging is a highly accurate technique for evaluation of the labrum and cartilage in patients with clinically suspected FAI.

Association between traumatic bone marrow abnormalities of the knee, the trauma mechanism and associated soft-tissue knee injuries.

OBJECTIVES: To determine the association between traumatic bone marrow abnormalities, the knee injury mechanism, and associated soft tissue injuries in a larger cohort than those in the published literature. METHOD: Retrospective study including 220 patients with traumatic knee injuries. Knee MRIs were evaluated for trauma mechanism, soft tissue injury, and the location of bone marrow abnormalities. The locations of the abnormalities were correlated with trauma mechanisms and soft tissue injuries using the chi-square test with Bonferroni correction. RESULTS: One hundred and forty-four valgus injuries, 39 pivot shift injuries, 25 lateral patellar dislocations, 8 hyperextensions, and 4 dashboard injuries were included. Valgus and pivot shift injuries showed traumatic bone marrow abnormalities in the posterolateral regions of the tibia. Abnormalities after patellar dislocation were found in the anterolateral and centrolateral femur and patella. Hyperextension injuries were associated with abnormalities in almost all regions, and dashboard injuries were associated with changes in the anterior regions of the tibia and femur. CONCLUSIONS: Our study provides evidence of associations between traumatic bone marrow abnormality patterns and different trauma mechanisms in acute knee injury, and reveals some overlap, especially of the two most common trauma mechanisms (valgus and pivot shift), in a large patient cohort. KEY POINTS: • Specific bone marrow oedema patterns after knee trauma were confirmed. • New associations between bone marrow oedema patterns and knee trauma were shown. • Bone marrow oedema patterns help in identifying associated soft tissue injuries.

Imaging of Athletic Injuries of Knee Ligaments and Menisci: Sports Imaging Series.

Acute knee injuries are a common source of morbidity in athletes and if overlooked may result in chronic functional impairment. Magnetic resonance (MR) imaging of the knee has become the most commonly performed musculoskeletal MR examination and is an indispensable tool in the appropriate management of the injured athlete. Meniscal and ligamentous tearing are the most frequent indications for surgical intervention in sports injuries and an understanding of the anatomy, biomechanics, mechanisms of injury, and patterns of injury are all critical to accurate diagnosis and appropriate management. These will be discussed in reference to meniscal tears and injuries of the cruciate ligaments as well as injuries of the posterolateral and posteromedial corners of the knee. (©) RSNA, 2016.

MRI of Labral and Chondral Lesions of the Hip.

OBJECTIVE: Unenhanced MRI, indirect MR arthrography, and direct MR arthrography have been used in the radiologic evaluation of patients with suspected labral tears and chondral lesions of the hip. The purpose of this article is to examine the existing evidence for the use of these techniques in patients with hip pain and suspected labral or chondral abnormalities. CONCLUSION: Evidence from a review of the radiologic literature supports the use of direct MR arthrography over unenhanced MRI and indirect MR arthrography for the detection of labral and cartilage abnormalities in the hip. Although high-resolution unenhanced 3-T MRI appears promising, limited information in the literature supports its use in the detection and characterization of chondrolabral lesions.

Diffusion tensor imaging of peripheral nerves.

Diffusion tensor imaging (DTI) is a powerful MR imaging technique that can be used to probe the microstructural environment of highly anisotropic tissues such as peripheral nerves. DTI has been used predominantly in the central nervous system, and its application in the peripheral nervous system does pose some challenges related to imaging artifacts, the small caliber of peripheral nerves, and low water proton density. However advances in MRI hardware and software have made it possible to use the technique in the peripheral nervous system and to obtain functional data relating to the effect of pathologic processes on peripheral nerves. This article reviews the imaging principles behind DTI and examines the literature regarding its application in assessing peripheral nerves.