Single slice MR image estimation of 3D supraspinatus intramuscular fatty infiltration in older adults: relevance for clinical practice and research.

OBJECTIVE: (1) To compare older adults stratified by supraspinatus tendon tear status (STT status)-no tear (Intact), partial-thickness (PT) tear, full-thickness (FT) tear-by 3D Dixon fat fraction (3D-FF); 2D fat fraction (2D-FF); and 2D Goutallier grade (2D-GG) at the Y-shaped view, and 1.4 cm and 2.8 cm medial to the Y-shaped view. Stratified by STT status to determine (2) correlation of 3D-FF with 2D-FF and 2D-GG and (3) inter-rater reliability at and medial to the Y-shaped view. MATERIALS AND METHODS: Forty-five volunteers ≥ 60 years recruited prospectively received shoulder MRI. 3D-FF and 2D-FF were measured on 6-point-Dixon MRI by three trainees. Goutallier grade was assessed on T1-weighted MRI by three fellowship-trained diagnostic radiologists. Descriptive, reliability, and correlation analyses were performed. RESULTS: Groups showed no difference in age. The FT group showed higher (p < 0.05) mean 3D-FF (14.09% ± 10.99%), mean 2D-FF (1.4 cm medial to Y-shaped view, 14.91% ± 12.11%; 2.8 cm medial to Y-shaped view, 13.32% ± 9.48%), and mean 2D-GG (Y-shaped view, 1.71 ± 0.78; 1.4 cm medial to Y-shaped view, 1.71 ± 0.69; 2.8 cm medial to Y-shaped view, 1.71 ± 0.72), relative to Intact/PT groups. 3D-FF showed strong correlation with 2D-FF among all groups/all analyses (rho, 0.80-0.98; p < 0.001). 3D-FF showed strong correlation with 2D-GG for all FT group analyses (rho, 0.85-0.91; p < 0.05). 3D-FF showed moderate-to-strong correlation considering all Intact/PT group analyses (rho, 0.51-0.79; p < 0.50). Dixon fat fraction showed excellent reliability for all groups (≥ 0.884, intraclass correlation coefficient). Goutallier grade showed excellent reliability for FT group (0.771, weighted Fleiss's kappa) but poor (0.294) and fair (0.502) for Intact and PT groups, respectively. CONCLUSION: Single slice MR image estimation of 3D supraspinatus intramuscular fatty infiltration has merit for continued use in clinical populations requiring potential rotator-cuff-repair surgery. However, Dixon fat fraction should be prioritized for use in research over Goutallier grade due to superior reliability.

Spectrum of imaging findings in soft-tissue necrosis.

Soft tissue necrosis can occur at different tissue levels, with numerous underlying causes. In this pictorial review, we highlight myonecrosis, and its accompanying stages, fat necrosis, devitalized soft tissue seen with infection, and necrotizing soft tissue infections. Imaging examples are provided with each entity.

Paraneoplastic musculoskeletal disorders: review and update for radiologists.

Rheumatic paraneoplastic syndromes are rare syndromes that occur at distant sites from the underlying tumor and may involve the bones, joints, fasciae, muscles, or vessels. In the absence of a known tumor, early recognition of a rheumatic syndrome as paraneoplastic permits dedicated work-up for, and potentially early treatment of an occult malignancy. Although there is a continuously growing list of paraneoplastic rheumatic disorders, not all of these disorders have a well-established association with a neoplastic process. The goals of this article are to review the clinical characteristics, diagnostic work-up, and imaging findings of well-documented rheumatic paraneoplastic disorders.

Low-velocity, civilian firearm extremity injuries-review and update for radiologists.

Firearm injuries are a preventable epidemic in the USA. Extremities are commonly affected in gunshot injuries. Such injuries may be complex with concomitant osseous, soft tissue, and neurovascular components. The maximum wounding potential of a projectile is determined by its kinetic energy and the proportion of the kinetic energy that is transmitted to the target. Accurate assessment of ballistic injuries is dependent on utilizing the principles of wound ballistics, accurate bullet count, and ballistic trajectory analysis. The goals of this article are to review wound ballistics and the imaging evaluation of extremity civilian firearm injuries in the adult population, with emphasis on ballistic trajectory analysis, specific ballistic fracture patterns, and diffuse, secondary soft tissue ballistic injuries.

Update of pediatric soft tissue tumors with review of conventional MRI appearance-part 1: tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors.

There are numerous soft tissue tumors and tumor-like conditions in the pediatric population. Magnetic resonance imaging is the most useful modality for imaging these lesions. Although certain soft tissue lesions exhibit magnetic resonance features characteristic of a specific diagnosis, most lesions are indeterminate, and a biopsy is necessary for diagnosis. We provide a detailed update of soft tissue tumors and tumor-like conditions that occur in the pediatric population, emphasizing each lesion's conventional magnetic resonance imaging appearance, using the recently released 5th edition of the World Health Organization Classification of Soft Tissue and Bone Tumors as a guide. In part one of this review, pediatric tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors are discussed. In part two, vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas are reviewed. Per the convention of the WHO, these lesions involve the connective, subcutaneous, and other non-parenchymatous-organ soft tissues, as well as the peripheral and autonomic nervous system.

Update of pediatric soft tissue tumors with review of conventional MRI appearance-part 2: vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas.

There are numerous soft tissue tumors and tumor-like conditions in the pediatric population. Magnetic resonance imaging is the most useful modality for imaging these lesions. Although certain soft tissue lesions exhibit magnetic resonance features characteristic of a specific diagnosis, most lesions are indeterminate, and a biopsy is necessary for diagnosis. We provide a detailed update of soft tissue tumors and tumor-like conditions that occur in the pediatric population, emphasizing each lesion's conventional magnetic resonance imaging appearance, using the recently released 5th edition of the World Health Organization Classification of Soft Tissue and Bone Tumors as a guide. In part one of this review, pediatric tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors are discussed. In part two, vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas are reviewed. Per the convention of the WHO, these lesions involve the connective, subcutaneous, and other non-parenchymatous organ soft tissues, as well as the peripheral and autonomic nervous system.

Meniscal Allograft Transplantation: A Pictorial Review.

Meniscal allograft transplantation may be indicated in a subset of patients with high-grade meniscectomy or irreparable meniscal injury and persistent knee pain that is resistant to conservative management. Meniscal allograft transplantation has demonstrated good to excellent results in short-term to midterm follow-up studies and satisfactory outcomes in long-term studies. The goals of this article are to review the indications, preoperative imaging assessment, surgical techniques, and postoperative assessment of uncomplicated and complicated meniscal allograft transplants.

Current concepts of spondylosis and posterior spinal motion preservation for radiologists.

Spinal fusion is performed to eliminate motion at a degenerated or unstable segment. However, this is associated with loss of motion at the fused levels and increased stress on adjacent levels. Motion-preserving implants have been designed in effort to mitigate the limitations of fusion. This review will focus on posterior spinal motion-preserving technologies. In the cervical spine, laminoplasty is a posterior motion-preserving procedure used in the management of myelopathy/cord compression. In the lumbar spine, motion-sparing systems include interspinous process devices (also referred to as interspinous process spacers or distraction devices), posterior dynamic stabilization devices (also referred to as pedicle screw/rod fixation-based systems), and posterior element replacement systems (also referred to as total facet replacement devices). Knowledge of the intended physiologic purpose, hardware utilized, and complications is important in the assessment of imaging in those who have undergone posterior motion preservation procedures.

Non-interventional Radiology Fellowship Programs: What Is Out There?

OBJECTIVE: To determine the spectrum of non-interventional radiology fellowship programs in institutions that offer both a radiology residency program and one or more non-interventional radiology fellowship programs. METHODS: Institutions offering both radiology residency and non-interventional radiology fellowship programs were identified using publicly available websites. The non-interventional radiology fellowship programs were categorized into "traditional" (neuroradiology, breast imaging, abdominal imaging, musculoskeletal imaging, thoracic imaging, pediatric radiology, and nuclear medicine) and "nontraditional" fellowship programs. The nontraditional programs were stratified into four categories: a) Combinations of traditional fellowships; b) Focused nontraditional fellowships; c) Combinations of traditional and focused nontraditional fellowships (excluding traditional-traditional combinations); and d) Mandatory two-year fellowships. The distributions of the different types of traditional and nontraditional fellowship programs were evaluated. RESULTS: 555 fellowship programs were identified in 113 institutions that offered both radiology residency and non-interventional radiology fellowship programs. 73.33% (407/555) of the programs were traditional fellowships, and 26.66% (148/555) were nontraditional fellowships. The 148 nontraditional fellowship programs were comprised of 41 different types of programs, 23 types of which were unique to and offered exclusively at specific institutions. 38.08% of the traditional fellowship programs were Accreditation Council for Graduate Medical Education (ACGME) accredited, while only 16.21% (24/148) of the nontraditional fellowship programs were ACGME-accredited. CONCLUSIONS: The nontraditional non-interventional radiology fellowship programs are formed by a heterogeneous group of programs, some of which are offered exclusively at a single institution. Awareness of the types of existing programs would help radiology residents in making a more informed decision regarding their fellowship training.

Surgical techniques for management of acromioclavicular joint separations: review and update for radiologists.

Imaging plays a central role in the postoperative management of acromioclavicular (AC) joint separations. There are more than 150 described techniques for the surgical management of AC joint injuries. These procedures can be categorized as varying combinations of the following basic techniques: a) soft-tissue repair, b) trans-articular AC joint fixation, c) coracoclavicular (CC) fixation, d) non-anatomic reconstruction of the CC ligaments, e) anatomic reconstruction of the CC ligaments, f) distal clavicle resection, and g) dynamic muscle transfer. The goals of this article are to describe the basic techniques for the surgical management of AC joint separations with an emphasis on technique-specific complications and postoperative imaging assessment.

Prosthetic joint infections: diagnosis, management, and complications of the two-stage replacement arthroplasty.

Despite improved strategies to prevent prosthetic joint infection, as the total number of joint replacements increases, so does the absolute number of infections. Radiography serves as the first-line imaging modality for the assessment of a suspected prosthetic joint infection. Additionally, serial radiographs acquired after a surgery to eradicate a prosthetic joint infection are an important clinical tool. Prosthetic joint infections are often treated with a 2-stage replacement arthroplasty utilizing a prosthesis with antibiotic-loaded acrylic cement. While complications are uncommon with this procedure, imaging may demonstrate periprosthetic fractures, as well as spacer migration, joint dislocation, and spacer fracture. We describe the classification of prosthetic joint infections, the clinical and imaging diagnosis, and treatment strategies. Familiarity with the hardware utilized in the management of the prosthetic joint infection, and its potential complications is fundamental to accurate imaging interpretation.

Clavicle Fractures: Review and Update for Radiologists.

Clavicle fractures are relatively common injuries that are typically diagnosed and followed with plain radiography. The goals of this article are to review the imaging evaluation, common classification systems, and relative surgical indications for clavicle fractures.

Preoperative MRI for the Multiligament Knee Injury: What the Surgeon Needs to Know.

The multiligament knee injury is devastating and potentially limb threatening. Preoperative magnetic resonance imaging for the evaluation of the multiligament knee injury is an invaluable clinical tool, and when the radiologist is familiar with how certain injury patterns influence management, optimal outcomes can be achieved. We provide a detailed description of the relationship between salient imaging features of the multiligament knee injury, focusing on the preoperative magnetic resonance imaging, and their influence on clinical decision-making.

External fixators: looking beyond the hardware maze.

External fixation has a wide variety of orthopedic applications. Although external fixator frames may have a complex appearance, these constructs are formed from several basic components and can be broadly categorized into unilateral, circular, or hybrid designs. The introduction of computer-aided circular external fixation devices (hexapod frames) has simplified the treatment of multiaxial and especially rotational deformities. Serial radiography plays a central role in the evaluation of callus formation (at the level of treated fracture or nonunion as well as the regenerate and docking site with distraction osteogenesis), tailoring the rate and rhythm of distraction during distraction osteogenesis, evaluation of frame complications, and determination of the timing of frame removal. The goals of this article are to review: the components, types, and relevant terminology of external fixator constructs with special emphasis on the Taylor spatial frame, the principles and techniques of distraction osteogenesis, and complications of external fixation.

Acute Shoulder Injury.

Acute shoulder injury is commonly encountered by clinicians, surgeons, and radiologists. A comprehensive evaluation of the shoulder by the radiologist is essential to accurately relay findings that have a direct impact on acute and long-term management. In this review, imaging features of acute injuries involving the proximal humerus, glenohumeral joint, rotator cuff, tendon of the long head of the biceps brachii, and acromioclavicular joint are discussed. Modalities include ultrasound examination, conventional radiography, computed tomography scans, and MR imaging. Emphasis is placed on radiographic features that have an impact on patient management.

Scapulothoracic dissociation.

Scapulothoracic dissociation is a rare and potentially limb- and life-threatening injury, that results from high-energy trauma. Scapulothoracic dissociation has the potential to be overlooked in the acute setting, especially in the setting of polytrauma. Therefore, a careful search for this condition should be performed in all patients with high-energy shoulder girdle injuries. The goals of this article are to review the anatomy of the scapulothoracic articulation as well as the spectrum, imaging evaluation, differential diagnosis and management of scapulothoracic dissociations.