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.

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.

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.

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.

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.

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.

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.

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.

Fragility fractures of the proximal femur: review and update for radiologists.

Proximal femoral fragility fractures are common and result in significant morbidity and mortality along with a considerable socioeconomic burden. The goals of this article are to review relevant proximal femoral anatomy together with imaging, classification, and management of proximal femoral fragility fractures, and their most common complications. Imaging plays an integral role in classification, management and follow-up of proximal femoral fragility fractures. Classification of proximal femoral fragility fractures is primarily based on anteroposterior hip radiographs. Pertinent imaging features for each category of proximal femoral fractures that would guide management are: differentiating nondisplaced from displaced femoral neck fractures, distinguishing stable from unstable intertrochanteric fractures, and determining the morphology and comminution of subtrochanteric fractures. Treatment of proximal femoral fragility fractures is primarily surgical with either arthroplasty or internal fixation. Intramedullary nailing is used in the treatment of some types of proximal femoral fragility fractures and may be associated with unique complications that become evident on postoperative follow-up radiographs.

Terrible triad injuries of the elbow.

Terrible triad injury of the elbow is a complex injury that is classically defined as elbow dislocation along with fractures of the coronoid process of the ulna and the radial head. The injury is usually associated with typical soft-tissue disruptions (with common involvement of the lateral collateral ligament complex, elbow joint capsule, as well as the common extensor and flexor-pronator tendons) that are best understood in the context of injury mechanism as well as the role and relevance of the various elbow stabilizers. The goals of this article are to review the pertinent anatomy, mechanism of injury, classification and imaging of terrible triad injuries of the elbow with brief descriptions of treatment, and complications of this complex injury.

The floating shoulder.

The floating shoulder refers to a subset of complex shoulder injuries that typically occur in the setting of high-energy trauma. Identification of the full extent of complex shoulder injuries with computed tomography may have critical implications in patient management. The goals of this article are to review the anatomy, definition, imaging evaluation, and treatment of floating shoulder injuries.

Anterior cervical discectomy and fusion: review and update for radiologists.

OBJECTIVES: The goals of this article are to describe the various types of interbody grafts and anterior cervical plating systems, techniques for optimizing evaluation of cervical spine metallic implants on CT and MR imaging, expected appearance and complications of ACDF on postoperative imaging and imaging assessment of fusion. Optimization for optimizing metal induced artifacts. CONCLUSION: Currently, ACDF is the most commonly performed surgical procedure for degenerative cervical spine disease. Interbody fusion is performed with bone grafts or interbody spacers, and may be supplemented with anterior cervical plating. Compressive pathologies at the vertebral body level may be addressed by simultaneous corpectomy. Postoperatively, imaging plays an integral role in routine screening of asymptomatic individuals, fusion assessment and evaluation of complications.

Update on the operative treatment of scapholunate instability for radiologists. II. Salvage procedures, total wrist arthrodesis, and total wrist arthroplasty.

Scapholunate (SL) instability is the most common form of carpal instability. Imaging (especially radiography) plays an important role in the staging, management, and postoperative follow-up of SL instability. In the final stage of SL instability, known as scapholunate advanced collapse, progressive degenerative changes occur at the carpal level. The goals of this article are to review the surgical options available for addressing the different stages of scapholunate advanced collapse, along with an emphasis on normal postoperative imaging and complications associated with each surgical option.

Update on operative treatment of scapholunate (SL) instability for radiologists: part 1-SL ligament repair, dorsal capsulodesis and SL ligament reconstruction.

Scapholunate instability is the most common form of carpal instability. Imaging (especially radiography) plays an important role in the staging, management and post-operative follow-up of scapholunate (SL) instability. The goals of this article are to review the pre-operative staging of SL instability, the surgical options for repair and reconstruction of the SL ligament, along with the normal postoperative imaging findings as well as complications associated with these surgical options.

Case 228: Mueller-Weiss Disease.

History A 53-year-old woman presented to the hospital for evaluation of progressive long-standing left dorsomedial foot pain, which was made worse with weight bearing. There was no history of trauma. Prior assessments were performed at another facility, and she did not to respond to conservative therapy. History was negative for systemic disorders. Physical examination revealed tenderness over the left talonavicular joint and flattening of the medial arch of the left foot. Otherwise, the findings were unremarkable. A basic serum chemistry test and complete blood count revealed no abnormal findings. The patient underwent routine weight-bearing radiography of her left foot and weight-bearing computed tomography (CT) of both feet.

Understanding carpal instability: a radiographic perspective.

The wrist is disposed to a variety of instability patterns owing to its complex anatomical and biomechanical properties. Various classification schemes have been proposed to describe the different patterns of carpal instability, of which the Mayo classification is the most commonly used. Understanding the concepts and pertinent terminology of this classification scheme is important for the correct interpretation of images and optimal communication with referring physicians. Standard wrist radiographs are the first line of imaging in carpal instability. Additional information may be obtained with the use of stress radiographs and other imaging modalities.

Errors of epinephrine administration during severe allergic-like contrast reactions: lessons learned from a bi-institutional study using high-fidelity simulation testing.

PURPOSE: To determine the most common errors of epinephrine administration during severe allergic-like contrast reaction management using high-fidelity simulation surrogates. MATERIALS AND METHODS: IRB approval and informed consent were obtained for this HIPAA-compliant bi-institutional prospective study of 40 radiology residents, fellows, and faculty who were asked to manage a structured high-fidelity severe allergic-like contrast reaction scenario (i.e., mild hives progressing to mild bronchospasm, then bronchospasm unresponsive to bronchodilators, and finally anaphylactic shock) on an interactive manikin. Intravenous (IV) and intramuscular epinephrine ampules were available to all participants, and the manikin had a functioning intravenous catheter for all scenarios. Video recordings of their performance were reviewed by experts in contrast reaction management, and errors in epinephrine administration were recorded and characterized. RESULTS: No participant (0/40) failed to give indicated epinephrine, but more than half (58% [23/40]) committed an error while doing so. The most common mistake was to administer epinephrine as the first-line treatment for mild bronchospasm (33% [13/40]). Other common errors were to administer IV epinephrine without a subsequent IV saline flush or concomitant IV fluids (25% [10/40]), administer an overdose of epinephrine (8% [3/40]), and administer epinephrine 1:1000 intravenously (8% [3/40]). CONCLUSION: Epinephrine administration errors are common. Many radiologists fail to administer albuterol as the first-line treatment for mild bronchospasm and fail to flush the IV catheter when administering IV epinephrine. High-fidelity contrast reaction scenarios can be used to identify areas for training improvement.

Imaging of postpartum complications: a multimodality review.

OBJECTIVE: The purpose of this article is to review common and uncommon complications of postpartum and posttermination patients and their imaging findings. A variety of imaging modalities, including ultrasound, CT, MRI, and angiography, will be presented. Knowledge of the spectrum of normal and abnormal imaging findings as well as recognition of the common and uncommon complications are essential for accurate diagnosis. CONCLUSION: Obstetric complications are a common source of morbidity and mortality for women of reproductive age. Imaging, particularly with ultrasound, is often supplementary to the clinical history and examination in assessing and treating women during the postpartum period. Radiologists should be familiar with the common abnormalities that present in this period and their imaging findings, as well as the wide range of normal appearances the postpartum uterus can assume.