Faculty Bibliography

The posteromedial and posterolateral corners of the knee are important areas to consider when assessing the patient with a possible knee injury. An understanding of the anatomy, associated biomechanics, and typical injury patterns in these regions will improve the value that the radiologist interpreting the MRIs brings to this patient population.

OBJECTIVE:Computerized tomography (CT) is the modality of choice for imaging bone; however, it utilizes ionizing radiation and suffers from poor soft-tissue contrast. Unlike CT, magnetic resonance imaging (MRI) provides excellent soft-tissue contrast but is limited in its ability to image bone. The objective of this study is to describe a new technical innovation which provides superior cortical and trabecular bone contrast on MRI. METHODS:FRACTURE (fast field echo resembling a CT using restricted echo-spacing), a 3D gradient echo pulse sequence with restricted echo-spacing combined with an automated post-processing, is described. RESULTS:Cases demonstrating the application and utility of this technique in diagnostic MRI performed for traumatic, inflammatory, neoplastic, and developmental conditions in pediatric patients are presented. CONCLUSION/CONCLUSIONS:The cortical and trabecular bone contrast generated by FRACTURE yields clinically relevant information for diagnosis and management of a subset of patients in whom it may potentially obviate the need for a preoperative CT scan.

Background/UNASSIGNED:Traumatic and chronic overuse injuries of the wrist are common in athletes. The purpose of this study was to describe the frequency, anatomic distribution, and severity of MRI-detected wrist joint injuries amongst athletes who competed in the Rio de Janeiro 2016 Summer Olympics. Methods/UNASSIGNED:All sports injuries reported by the National Olympic Committee medical teams and the Organizing Committee medical staff during the 2016 Summer Olympics were analyzed. MRI was performed at the International Olympic Committee's polyclinic within the Olympic Village, using 3T and 1.5T scanners. The MRIs were interpreted by musculoskeletal radiologists with expertise in sports injuries. The distribution of wrist injuries by anatomic location and sports discipline and the severity of injuries were recorded. Results/UNASSIGNED:A total of 1,101 injuries were reported in the 11,274 athletes. Twenty-five athletes (72% male, median-age =27 years) had an MRI for wrist injuries. Fifty-six percent (N=14) of these athletes had triangular fibrocartilage pathology, 64% of which were chronic, while 36% were acute. There were scapholunate ligament injuries in 40% of the athletes. The extensor carpi ulnaris tendon was most commonly injured tendon. Fractures were seen in 32% of the athletes (N=8) and most commonly involved the scaphoid. Athletes participating in weightlifting (N=4, 16%), tennis (N=3, 12%) and gymnastics (N=3, 12%) athletes were most commonly affected. Conclusions/UNASSIGNED:MRI-detected wrist injuries during the 2016 Summer Olympics most commonly affected the scapholunate ligament, extensor carpi ulnaris tendon and triangular fibrocartilage articular disc. The highest occurrence of wrist injuries was in weightlifting, tennis and gymnastics.

Calvarial abnormalities are usually discovered incidentally on radiologic studies or less commonly manifest with symptoms. This narrative review describes the imaging spectrum of the abnormal calvaria. The extent, multiplicity, and other imaging features of calvarial abnormalities can be combined with the clinical information to establish a final diagnosis or at least narrow the differential considerations. Prior trauma (congenital depression, leptomeningeal cysts, posttraumatic osteolysis), surgical intervention (flap osteonecrosis and burr holes), infection, and inflammatory processes (sarcoidosis) can result in focal bone loss, which may also be seen with idiopathic disorders without (bilateral parietal thinning and Gorham disease) or with (Parry-Romberg syndrome) atrophy of the overlying soft tissues. Anatomic variants (arachnoid granulations, venous lakes, parietal foramina) and certain congenital lesions (epidermoid and dermoid cysts, atretic encephalocele, sinus pericranii, and aplasia cutis congenita) manifest as solitary lytic lesions. Other congenital entities (lacunar skull and dysplasia) display a diffuse pattern of skull involvement. Several benign and malignant primary bone tumors involve the calvaria and manifest as lytic, sclerotic, mixed lytic and sclerotic, or thinning lesions, whereas multifocal disease is mainly due to hematologic or secondary malignancies. Metabolic disorders such as rickets, hyperparathyroidism, renal osteodystrophy, acromegaly, and Paget disease involve the calvaria in a more diffuse pattern. Online supplemental material is available for this article. ^©RSNA, 2021.

PURPOSE/OBJECTIVE:To assess the utility of a 2D dynamic HASTE sequence in assessment of cervical spine flexion-extension, specifically (1) comparing dynamic spondylolisthesis to radiographs and (2) assessing dynamic contact upon or deformity of the cord. METHODS:Patients with a dynamic flexion-extension sagittal 2D HASTE sequence in addition to routine cervical spine sequences were identified. Static and dynamic listhesis was first determined on flexion-extension radiographs reviewed in consensus. Blinded assessment of the dynamic HASTE sequence was independently performed by 2 radiologists for (1) listhesis and translation during flexion-extension and (2) dynamic spinal cord impingement (cord contact or deformity between neutral, flexion and extension). RESULTS:32 scans in 32 patients (9 males, 23 females) met inclusion criteria acquired on 1.5 T (n = 15) and 3 T (n = 17) scanners. The mean acquisition time was 51.8 s (range 20-95 seconds). Dynamic translation was seen in 14 patients on flexion-extension radiographs compared to 12 (reader 1) and 13 (reader 2) patients on HASTE, with 90.6 % agreement (K = 0.83; p = 0.789). In all cases dynamic listhesis was ≤3 mm translation with one patient showing dynamic listhesis in the range 4-6 mm. Four cases (13 %) demonstrated deformity of the cord between flexion-extension, not present in the neutral position. For cord impingement there was strong inter-reader agreement (K = 0.93) and the paired sample Wilcoxon signed rank test found no significant difference between the impingement scores of the two readers (p = 0.787). CONCLUSIONS:A sagittal dynamic flexion-extension HASTE sequence provides a rapid addition to standard MRI cervical spine protocols, which may useful for assessment of dynamic spondylolisthesis and cord deformity.

BACKGROUND:Athletes are prone to both acute and chronic overuse injuries of the elbow joint. The purpose of this study was to describe the frequency, anatomic distribution, and severity of magnetic resonance imaging (MRI)-detected elbow joint injuries among athletes who competed in the Rio de Janeiro 2016 Summer Olympics. METHODS:All sports injuries reported by the National Olympic Committee medical teams and the Organizing Committee medical staff during the 2016 Summer Olympics were analyzed. Magnetic resonance imaging was performed at the International Olympic Committee's polyclinic within the Olympic Village, using 3- and 1.5-T scanners. The MRIs were read centrally and retrospectively by musculoskeletal radiologists with expertise in sports injuries. The distribution of elbow joint injuries by anatomic location and sports discipline and the severity of injuries were recorded. RESULTS:A total of 1101 injuries were reported in the 11,274 athletes from 207 teams at the Games. Central review of MRI revealed elbow joint injuries in 15 athletes (60% male; median age, 22 years; range, 18-39 years). Ligamentous injuries were most common, with injuries of the ulnar collateral ligament being the most prevalent (n = 12; 80%), followed by the common flexor tendon (n = 8; 53%). Osseous injuries were far less common (n = 3; 20%), with no acute fractures seen. Weightlifting (n = 4; 27%) and judo (n = 4; 27%) athletes were most commonly affected. CONCLUSION/CONCLUSIONS:Magnetic resonance imaging-detected elbow injuries during the 2016 Summer Olympics affected mainly the ulnar collateral ligament and the common flexor tendon, with the highest occurrence in weight lifting and judo.

Osteoarthritis (OA) is the most common joint disease in the United States. The prevalence of OA is rising due to an aging population and increasing rates of obesity. Magnetic resonance imaging (MRI) allows an incomparable noninvasive assessment of all joint structures. Irreversible and progressive degradation of the articular cartilage remains the hallmark feature of OA. To date, attempts at developing disease-modifying drugs or biomechanical interventions for treating OA have proven unsuccessful. MRI-based cartilage imaging techniques have continued to advance, however, and will likely play a central role in the development of these joint preservation methods of the future. In this narrative review, we describe clinical MR image acquisition and assessment of cartilage. We discuss the semiquantitative cartilage scoring methods used in research. Lastly, we review the quantitative MRI techniques that allow assessment of changes in the biochemical composition of cartilage, even before the morphological changes are evident.

Lower extremity superficial venous aneurysms are occasionally encountered by clinicians and are almost always located above the knee. Very few cases of aneurysm of the medial marginal vein in the most distal part, near the origin of the great saphenous vein, have been reported. We present a case of partially thrombosed aneurysm of the medial marginal vein, and briefly review the imaging characteristics and treatment options of this entity. Being aware of the existence of superficial venous aneurysms may help clinicians in their differential diagnosis of foot masses and choice of appropriate treatment.

Synovitis and joint effusion are common manifestations of rheumatic disease and play an important role in the disease pathophysiology. Earlier detection and accurate assessment of synovial pathology, therefore, can facilitate appropriate clinical management and hence improve prognosis. Magnetic resonance imaging (MRI) allows unparalleled assessment of all joint structures and associated pathology. It has emerged as a powerful tool, which enables not only detection of synovitis and effusion, but also allows quantification, detailed characterization, and noninvasive monitoring of synovial processes. The purpose of this article is to summarize the pathophysiology of synovitis and to review the role of qualitative, semiquantitative, and quantitative MRI in the assessment of synovitis and joint fluid. We also discuss the utility of MRI as an outcome measure to assess treatment response, particularly with respect to osteoarthritis and rheumatoid arthritis. Emerging applications such as hybrid positron emission tomography / MRI and molecular imaging are also briefly discussed. Level of Evidence: 5 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019.