Calcaneal tuberosity avulsion fractures are often treated differently depending on several factors, including imaging diagnosis and classification. Timely identification of imaging findings, accurate interpretation, and effective communication can help avert serious clinical complications, including the necessity for soft tissue coverage and amputation. This article reviews the anatomy of the calcaneus, as well as the clinical and imaging findings of calcaneal tuberosity fractures. Imaging interpretation and clinical management of these fractures are discussed.

The complex and variable anatomy of the pectoralis major, and the evolving description of this anatomy and its patterns of injury in the literature contribute to the challenge in applying a standardized classification scheme for injuries [1, 2]. While pectoralis major injuries are uncommon injuries, their occurrence is increasing. Many patients after this injury will present to the emergency department. It is important for emergency radiologists to understand the imaging findings of these injuries. Diagnosis with magnetic resonance imaging (MRI) can avoid surgical delay and improve patient outcomes [3]. This article presents a focused anatomic and imaging discussion of pectoralis major injuries as seen on MRI.

Imaging evaluation for lower extremity infections can be complicated, especially in the setting of underlying conditions and with atypical infections. Predisposing conditions are discussed, including diabetes mellitus, peripheral arterial disease, neuropathic arthropathy, and intravenous drug abuse, as well as differentiating features of infectious versus non-infectious disease. Atypical infections such as viral, mycobacterial, fungal, and parasitic infections and their imaging features are also reviewed. Potential mimics of lower extremity infection including chronic nonbacterial osteomyelitis, foreign body granuloma, gout, inflammatory arthropathies, lymphedema, and Morel-Lavallée lesions, and their differentiating features are also explored.

In modern practice, imaging plays an integral role in the diagnosis, evaluation of extent, and treatment planning for lower extremity infections. This review will illustrate the relevant compartment anatomy of the lower extremities and highlight the role of plain radiographs, CT, US, MRI, and nuclear medicine in the diagnostic workup. The imaging features of cellulitis, abscess and phlegmon, necrotizing soft tissue infection, pyomyositis, infectious tenosynovitis, septic arthritis, and osteomyelitis are reviewed. Differentiating features from noninfectious causes of swelling and edema are discussed.

Nuclear medicine and the array of different radiotracers have an important role in the diagnosis and evaluation of a variety of musculoskeletal diseases. Conventional radiography has long been considered the first-line diagnostic for suspected traumatic fracture. Broadly speaking, stress fractures fall into one of two categories: fractures that arise from normal loading on abnormal bone, termed “insufficiency fractures,” and fractures that arise from abnormal loading on normal bone, termed “fatigue fractures”. Rheumatoid arthritis is an inflammatory disorder with a main target for the synovial membrane of joints, bursae, and tendon sheaths. Radiography is the mainstay in the preliminary evaluation of rheumatoid arthritis. Diabetic patients are at risk for foot infections due to underlying diabetic neuropathy, which leads to a loss of protective sensation and development of anatomic deformities and altered weight-bearing, and peripheral vascular disease, which limits access of phagocytic cells and antibiotics to infected sites due to impaired circulation.

Benign retroperitoneal tumors (BRT) represent a rare group of heterogeneous diseases. The literature lacks high-quality evidence about the optimal management of BRT, and most of the information available takes the form of case reports or case series. The aim of this review is to provide an overview of current management strategies for adult patients with BRT. A literature search using PubMed indexed articles was conducted and BRT were classified into five different biological subgroups: 1) lipomatous tumors, 2) smooth muscle tumors, 3) peripheral nerve sheath tumors, 4) myofibroblastic tumors, and 5) others. Tumors that are primarily pelvic in origin were excluded. Despite the significant heterogeneity of the disease, several generic considerations have emerged and can be applied to the management of BRT. Specifically, the risk of misdiagnosing a BRT with another pathology such as retroperitoneal sarcoma is notable. When encountered, suspected BRT should therefore be referred to a specialized sarcoma center. Multidisciplinary tumor boards, present at these centers, have a pivotal role in managing BRT. The decision of whether to offer surgery, nonsurgical treatment or a "watch-and-wait" approach should be made after multidisciplinary discussion, depending on tumor histology. Moving forward, collaborative research efforts dedicated to BRT remain crucial in gathering evidence and knowledge to further optimize patient care.

Understanding the subtle signs of carpal instability and other unique injury patterns in the wrist is a critical skill for radiologists. Proper patient management and outcomes are directly dependent on the accurate interpretation of wrist imaging studies. This review will provide a detailed overview of typical imaging features of carpal trauma and instability, management, and complications, using multimodality imaging and original medical illustrations. A detailed overview of the osseous, ligamentous, arterial anatomy of the wrist, arcs of Gilula, and zones of vulnerability will be provided. Carpal fractures, dislocations, special radiographic views, and imaging pearls will be discussed. Instability patterns and the myriad of associate abbreviations (CID, CIND, CIC, CIA, VISI, DISI, SLD, LTD, MCI, SLAC, SNAC) will be clarified. Expected outcomes, potential complications, and management will be reviewed.

Background: Although imaging is central in the initial staging of patients with soft tissue sarcomas (STS), it remains underused and few radiological features are currently used in practice for prognostication and to help guide the best therapeutic strategy. Yet, several prog- nostic qualitative and quantitative characteristics from magnetic resonance imaging (MRI) and positron emission tomography (PET) have been identified over these last decades. Objective: After an overview of the current validated prognostic features based on baseline imaging and their integration into prognostic tools, such as nomograms used by clinicians, the aim of this review is to summarize more complex and innovative MRI, PET, and radio- mics features, and to highlight their role to predict indirectly (through histologic grade) or directly the patients' outcomes.

Musculoskeletal soft-tissue infections include a wide range of clinical conditions that are commonly encountered in both emergency departments and non-emergency clinical settings. Since clinical signs, symptoms, and even laboratory tests can be unremarkable or non-specific, imaging plays a key role in many cases. MRI is considered the most comprehensive and sensitive imaging tool available for the assessment of musculoskeletal infections. Ultrasound is a fundamental tool, especially for the evaluation of superficially located diseases and for US-guided interventional procedures, such as biopsy, needle-aspiration, and drainage. Conventional radiographs can be very helpful, especially for the detection of foreign bodies and in cases of infections with delayed diagnosis displaying bone involvement. This review article aims to provide a comprehensive overview of the radiological tools available and the imaging features of the most common musculoskeletal soft-tissue infections, including cellulitis, necrotizing and non-necrotizing fasciitis, foreign bodies, abscess, pyomyositis, infectious tenosynovitis, and bursitis.

We report a case of a perivascular epithelioid cell tumor occurring in the falciform ligament of an otherwise healthy 32-year-old woman. The mass was hypervascular with central necrosis on computed tomography (CT) and contrast-enhanced ultrasound. Our case is unique as CT and ultrasound revealed a paraumbilical vein arising from the expected location in the fissure for the falciform ligament and terminating in the superior aspect of the mass. The vascular anatomy of a recanalized paraumbilical vein, typically associated with portal hypertension, was complete with drainage of blood from the inferior aspect of the mass through the inferior epigastric veins to the femoral veins. The patient had no evidence of liver disease or portal hypertension.

Ewing sarcoma is a primitive neuroectodermal tumor which seldom presents with primary disease in people over age 40 and outside of the appendicular or axial skeleton. We examine a case of primary thoracic Ewing Sarcoma diagnosed initially by CT-guided biopsy in a woman at the age of 74 years. The disease progressed after initial combined modality therapy consisting of neoadjuvant chemotherapy, surgical resection, and adjuvant radiation therapy and two additional courses of multiagent chemotherapy. After relapse of her disease, subsequent second- and third-line systemic agents which included chemotherapy and targeted agents were given with disease stabilization achieved now over 30 months from initial diagnosis. To our knowledge, this is the first report of a primary pulmonary Ewing sarcoma diagnosed in a patient greater than 70 years of age in whom multiple remissions have been achieved with tolerable toxicities.

Background The role of F-18-fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG PET/CT) in the evaluation of retroperitoneal sarcomas is poorly defined. We evaluated the correlation of maximum standardized uptake value (SUVmax) with pathologic tumor grade in the surgical specimen of primary retroperitoneal dedifferentiated liposarcoma (DDLPS) and leiomyosarcoma (LMS). Methods Patients with the above histological subtypes in three participating institutions with preoperative F-18-FDG PET/CT scan and histopathological specimen available for review were included. The association between SUVmax and pathological grade was assessed. Correlation between SUVmax and relapse-free survival (RFS) and overall survival (OS) were also studied. Results Of the total 58 patients, final pathological subtype was DDLPS in 44 (75.9%) patients and LMS in 14 (24.1%) patients. The mean SUVmax was 8.7 with a median 7.1 (range, 2.2-33.9). The tumors were graded I, II, III in 6 (10.3%), 35 (60.3%), and 17 (29.3%) patients, respectively. There was an association of higher histological grade with higher SUVmax (r(s) = 0.40, p = .002). Increasing SUVmax was associated with worse RFS (p = .003) and OS (p = .003). Conclusion There is a correlation between SUVmax and pathologic tumor grade; increasing SUVmax was associated with worse OS and RFS, providing a preoperative noninvasive surrogate marker of tumor grade and biological behavior.

This review article aims to reinforce anatomical concepts about meniscal tears while linking associated treatment options. The main teaching points start with the basic meniscal anatomy and key differences between the medial and lateral menisci. Subsequently, various meniscal tear patterns along with their associated history and physical exam findings will be discussed with corresponding illustrations and MR images. Additional discussion will involve the different surgical repair techniques (with arthroscopic correlates), their indications with pertinent imaging findings, imaging related to previous meniscal tear repairs, and novel surgical techniques. Lastly, keys to evaluating for retear with an emphasis on MRI arthrogram findings will be reviewed. While each of these topics is not discussed in totality, the key points of the review article will enforce key concepts and help radiologists evaluate the menisci on imaging.

Since the spread of the coronavirus disease 2019 (COVID-19) was designated as a pandemic by the World Health Organization, health care systems have been forced to adapt rapidly to defer less urgent care during the crisis. The United States (U.S.) has adopted a four-phase approach to decreasing and then resuming non-essential work. Through strong restrictive measures, Phase I slowed the spread of disease, allowing states to safely diagnose, isolate, and treat patients with COVID-19. In support of social distancing measures, non-urgent studies were postponed, and this created a backlog. Now, as states transition to Phase II, restrictions on non-essential activities will ease, and radiology departments must re-establish care while continuing to mitigate the risk of COVID-19 transmission all while accommodating this backlog. In this article, we propose a roadmap that incorporates the current practice guidelines and subject matter consensus statements for the phased reopening of non-urgent and elective radiology services. This roadmap will focus on operationalizing these recommendations for patient care and workforce management. Tiered systems are proposed for the prioritization of elective procedures, with physician-to-physician communication encouraged. Infection control methods, provision of personal protective equipment (PPE), and physical distancing measures are highlighted. Finally, changes in hours of operation, hiring strategies, and remote reading services are discussed for their potential to ease the transition to normal operations.

Spindle cell carcinoma (SpC), also known as metaplastic carcinoma-spindle cell type, is a subtype of metaplastic carcinoma. Metaplastic carcinomas of the breast are rare but are thought to be more aggressive than invasive ductal carcinomas. Due to their rarity, there are few randomized trials that can inform any standardized approaches to treatment. Treatment is instead extrapolated from other types of breast cancer or metaplastic carcinomas of different locations. Here we present the first known case report of a patient with spindle cell carcinoma of the breast successfully treated with a standard sarcoma neoadjuvant regimen of doxorubicin, ifosfamide, and mesna (AIM) that resulted in >99% necrosis of the tumor and negative margins at the time of resection.

The coccygeal region has complex anatomy, much of which may contribute to or be the cause of coccyx region pain (coccydynia). This anatomy is well depicted at imaging, and management is often dictated by what structures are involved. Coccydynia is a common condition that is known to be difficult to evaluate and treat. However, imaging can aid in determining potential causes of pain to help guide management. Commonly, coccydynia (coccygodynia) occurs after trauma and appears with normal imaging features at static neutral radiography, but dynamic imaging with standing and seated lateral radiography may reveal pathologic coccygeal motion that is predictive of pain. In addition, several findings seen at cross-sectional imaging in patients with coccydynia can point to a source of pain that may be subtle and easily overlooked. Radiology can also offer a role in management of coccygeal region pain with image-guided pain management procedures such as ganglion impar block. In addition to mechanical coccyx pain, a host of other conditions involving the sacrococcygeal region may cause coccydynia, which are well depicted at imaging. These include neoplasm, infection, crystal deposition, and cystic formations such as pilonidal cyst. The authors review a variety of coccydynia causes, their respective imaging features, and common management strategies.©RSNA, 2020.

A horseshoe abscess is caused by infection that spreads between the flexor tendon sheath of the thumb or little finger through the radial and ulnar bursae through communication between the two and/or the space of Parona. We present a case of an 80-year-old woman with rheumatoid arthritis who presented with 6 months of right hand and wrist soft tissue swelling, initially treated as a rheumatoid arthritis flare. MRI demonstrates the horseshoe abscess and after surgical irrigation and debridement with synovectomy, cultures demonstrated infection with mycobacterium avium intracellulare (MAI). This case demonstrates the importance of MRI in diagnosing and evaluating the extent of hand infections and for considering mycobacterial organisms for appropriate treatment and antibiotic regimen.

Liposarcoma is a malignancy of fat that commonly develops in the retroperitoneum (1,2). In this anatomic location, tumors can be low grade, well differentiated (WD) or have an additional high grade, dedifferentiated (DD) component. Entirely WD tumors are typically indolent and do not metastasize, while tumors with a DD component are more aggressive and have distant metastatic potential. WD and DD liposarcoma can be regarded as opposite ends of a spectrum of disease aggressiveness (e.g., lipoma-like WD to rhabdomyoblastic DD) (3). For patients with retroperitoneal (RP) liposarcoma, high resolution, contrast enhanced CT of the abdomen and pelvis is critical as part of the initial evaluation (4). This should be performed if not done already at the time of referral. WD liposarcomas are well-defined round or lobulated masses predominantly composed of macroscopic fat with few, thin septations (5). Non-fatty, soft tissue density areas with a ground glass appearance can occur and typically constitute less than 25% of the tumor (6). DD areas manifest as discrete nodular soft tissue density areas often with good demarcation from surrounding fat and show variable contrast enhancement. Internal septations are thicker (>2 mm) in DD. Calcifications may also be seen and would suggest DD liposarcoma if found in the nonfatty areas. For patients with suspected DD disease, CT of the chest should be obtained as part of staging to rule out distant metastasis to the lungs (4). To confirm the diagnosis of RP liposarcoma, percutaneous core needle biopsy can be performed. Biopsy may not always be necessary, especially in cases in which the radiologic features highly suggest the diagnosis. On histopathologic examination, WD liposarcoma consists of adipocytes of varying size with fibrous septae and interspersed hyperchromatic cells (7). DD areas are typically juxtaposed next to WD areas with an abrupt transition from the adipocytic (WD) to non-adipocytic, high grade appearing areas containing prominent mitotic figures (DD). Both WD and DD liposarcoma have amplification of 12q13-15 which includes several important genes such as MDM2 and CDK4. This molecular feature is considered pathognomonic and can be used for the definitive diagnosis if the histologic features alone are unclear. For all patients with nonmetastatic retroperitoneal liposarcoma, surgery is the mainstay of treatment. However, in the retroperitoneum, tumors are frequently massive in size and can potentially invade critical organs and major blood vessels, making surgery very difficult. Whether due to technical factors (e.g., “positive” margins) or disease biology [e.g., “field defect” (8)], recurrence rates after resection are high and do not plateau over time (9). Radiation therapy may offer improved local control, but the true benefit for retroperitoneal liposarcoma remains controversial (10). Sarcoma MDT Series