Myositis ossificans: a rare neonatal presentation.

Myositis ossificans is a benign, ossifying, soft-tissue pseudotumor that most commonly occurs in men ages 30-40 years after trauma. Myositis ossificans may also occur in children, but it is extremely rare in those younger than 10 years of age. While myositis ossificans can often mimic malignant soft-tissue tumors, it has many unique findings that can aid in diagnostic differentiation. This differentiation is critical to avoid unnecessary risk with potentially harmful procedures. We present a very unusual presentation of myositis ossificans in the immediate post-birth perinatal period, as well as a review of key imaging findings.

Recurrent Shoulder Posteroinferior Subluxation Status Post Reverse Remplissage.

Posterior shoulder dislocation is an uncommon injury that typically follows intense contraction of the external rotator muscles, such as from seizure activity, high-velocity trauma, or intense electrical shock. The diagnosis is often missed or delayed, leading to complications such as functional deficits or osteonecrosis of the humeral head. Closed reduction can be utilized following an initial occurrence, however, repeated insult to the glenohumeral joint may lead to posterior instability. A reverse Hill-Sachs lesion, a vertical impacted fracture of the anteromedial aspect of the humeral head, can occur. Surgical treatment options for posterior instability include the modified McLaughlin procedure also known as the reverse remplissage procedure. Unfortunately, the success rates of this procedure are controversial.

Fat-Finding Mission: Primary Pleomorphic Liposarcoma of the Heart and Pericardium.

Primary cardiac liposarcomas are rare tumors with a poor prognosis and no well-defined imaging characteristics or treatment guidelines. Here, we present a case of primary pleomorphic liposarcoma of the heart and pericardium with multimodality imaging findings and our institution's treatment approach. (Level of Difficulty: Intermediate.).

Parathyroid Auto-transplantation Mimicking Liposarcoma.

Parathyroid autotransplantation is an increasingly common procedure given the increasing rate of hyperparathyroidism. However, post-autotransplantation imaging is not commonly performed and the imaging findings can mimic liposarcoma. Therefore, radiologists should be aware of the imaging characteristics of parathyroid autotransplantation. Here we discuss the CT and Tc99m-Sestamibi 4D-CT findings of parathyroid autotransplantation. We will also discuss the pathophysiology of liposarcoma and present the gross histological findings seen on pathology.

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.

Standard and Advanced Imaging of Hip Osteoarthritis. What the Radiologist Should Know.

Osteoarthritis (OA) of the hip is caused by degeneration of articular cartilage and the underlying bone and can be divided into two types: primary (associated with advancing age) and secondary (subsequent to fractures, avascular necrosis, infection, developmental dysplasia, and femoroacetabular impingement). Radiography remains the first-line imaging modality for diagnosing and monitoring OA, due to its accessibility, low cost, and ease of interpretation. Kellgren-Lawrence and Tönnis classification systems are radiographic OA grading systems used primarily in research, and they reflect the degree of joint space narrowing, sclerosis, cysts, deformity of the femoral head and acetabulum, and osteophytes. Unenhanced computed tomography (CT) provides detailed visualization of the hip joint segments that may be difficult to appreciate on radiographs, such as the inferoposterior and posterolateral hip joint. CT arthrography, magnetic resonance imaging (MRI), and magnetic resonance arthrography with two-dimensional reconstructions can delineate labral abnormalities, cartilage lesions, and other intra-articular hip pathology. T2 and T2* mapping, delayed gadolinium-enhanced MRI of cartilage, T1rho, ultra-short echo time, and zero echo time are investigative MR techniques with promising evaluation of hip OA.

Filler Migration and Granuloma Formation After Gluteal Augmentation with Free-silicone Injections.

Gluteal augmentation may be performed using a variety of techniques, including implant-based, autologous fat grafting, local flaps, impermanent filler injection, or, as in this case, by way of permanent filler injection with free-silicone. Of these, free-silicone injections carry one of the highest complication rates, specifically regarding migration of the filler material from the native injection site and induction of painful reactive soft tissue changes at the new filler location. A radiologist providing this diagnosis may assist the clinician, who often cannot obtain a history of illicit silicone injection for gluteal augmentation unless the suspicion is raised. Presented here is a case of painful filler migration to the knee with granuloma formation after free-silicone gluteal injection.

Postoperative Imaging of Sarcomas.

OBJECTIVE: The purpose of this article is to assist radiologists in developing an organized, systematic approach to imaging interpretation in the care of patients who have been surgically treated for sarcoma. CONCLUSION: Postoperative imaging interpretation of sarcoma can be complex and requires an organized, systematic approach that includes review of the patient's clinical and surgical history and pretreatment images to gain context for differentiating recurrence from time-dependent posttreatment changes.

Multimodality Imaging of Calcinosis of Chronic Renal Failure.

Secondary tumoral calcinosis (STC) refers to periarticular calcified masses associated with an identifiable condition. The most common of these identifiable conditions is a chronic renal failure. We present a unique case in which massive periarticular masses in a patient with calcinosis of chronic renal failure (CCRF) are demonstrated in the shoulder and hip on sonography, radiography and computed tomography (CT).

Gadolinium Contrast Enhancement Improves Confidence in Diagnosing Recurrent Soft Tissue Sarcoma by MRI.

RATIONALE AND OBJECTIVES: To determine how utilization of postgadolinium magnetic resonance imaging (MRI) influenced reader accuracy and confidence at identifying postoperative soft tissue sarcoma (STS) recurrence among readers with various levels of expertise. MATERIALS AND METHODS: This retrospective study was institutional review board approved and Health Insurance Portability and Accountability Act compliant. Postoperative MRI from 26 patients with prior STS resection (13 patients with confirmed recurrence, 13 without recurrence) was reviewed. Four blinded readers of varying expertise (radiology resident, fellow, attending, and orthopedic oncologist) initially evaluated only the precontrast images and rated each MRI for recurrence on a 5-point confidence scale. Assessment was repeated with the addition of contrast-enhanced sequences. Diagnostic accuracy based on confidence ratings was evaluated using the area under the receiver operating characteristic curve (AUC). Changes in confidence ratings were calculated using Wilcoxon signed-rank test. RESULTS: All readers demonstrated good diagnostic accuracy both with and without contrast-enhanced images (AUC >0.98 for each reader). When contrast-enhanced images were made available, the resident recorded improved confidence with both assigning (P = 0.031) and excluding recurrence (P = 0.006); the fellow showed improved confidence only with assigning recurrence (P = 0.015); and the surgeon showed improved confidence in excluding recurrence (P = 0.003). The addition of contrast-enhanced images did not significantly influence the diagnostic confidence of the attending radiologist. CONCLUSIONS: Diagnostic accuracy of MRI was excellent in evaluating postoperative STS recurrence, and reader confidence improved depending on expertise when postgadolinium imaging was included in the assessment.

Juvenile myelomonocytic leukemia presenting as bilateral breast masses.

An 8-year-old girl presented with bilateral breast masses and was subsequently diagnosed with juvenile myelomonocytic leukemia. Juvenile myelomonocytic leukemia is a rare myelodysplastic syndrome that typically presents in boys younger than 3 years of age with splenomegaly, lymphadenopathy and skin findings. Bilateral breast masses in a child are rare and, as such, present a diagnostic dilemma due to the relative paucity of cases in the literature. We present a case of granulocytic sarcoma of the breasts in a patient with juvenile myelomonocytic leukemia. The authors hope that increased reporting and research regarding pediatric breast masses will help create awareness for such cases.

Recurrent radiation-induced osteosarcoma of the sternum in a patient with remote radiation therapy for breast cancer.

BACKGROUND: Recurrent radiation-induced osteosarcoma of the sternum following remote radiation therapy for breast cancer and sternal reconstruction. CASE: A 51-year-old woman presents with recurrent, radiation-induced sternal osteosarcoma 11 years after receiving both radiation therapy for breast cancer and sternal reconstruction. The case details both her work-up and subsequent course, including reconstructive and curative efforts. DISCUSSION: An uncommon side effect of radiation therapy for breast cancer is development of osteosarcoma of the chest wall. Even rarer is recurrence of the osteosarcoma following sternal reconstruction.

Ewing Sarcoma of the Pelvis with an Atypical Radiographic Appearance: A Mimicker of Non-malignant Etiologies.

Ewing sarcoma (ES) is a primary malignant bone tumor which most commonly arises in children and young adults. The common clinical presentation with ES includes nighttime pain or pain related to activity, though patients may also present with a combination of localized swelling, a palpable mass, pathologic fracture, and constitutional symptoms. Clinical diagnosis may be delayed when a patient presents with clinical or imaging findings that overlap with non-malignant etiologies, such as fibrous dysplasia (FD) or osteomyelitis. Furthermore, multimodality imaging, including computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine may prove inconclusive in particular cases. Suspicion for malignancy should not be overlooked. A biopsy must be considered, unless the diagnosis is evident, such as a clinical response to antibiotics in the setting of osteomyelitis.

CT and MR Imaging of the Postoperative Ankle and Foot.

A variety of surgical procedures exist for repair of both traumatic and degenerative osseous and soft-tissue pathologic conditions involving the foot and ankle. It is necessary for the radiologist to be familiar with these surgical procedures, so as to assess structural integrity, evaluate for complicating features, and avoid diagnostic pitfalls. Adequate interpretation of postoperative changes often requires access to surgical documentation to evaluate not only the surgery itself but the expected timeline for resolution of normal postoperative changes versus progressive disease. Appropriate use of surgical language in radiology reports is another important skill set to hone and is instrumental in providing a high-quality report to the referring surgeons. The pathophysiology of a myriad of surgical complaints, beginning from the Achilles tendon and concluding at the plantar plate, are presented, as are their common appearances at computed tomography and magnetic resonance imaging. Commonly encountered entities include Achilles tendon tear, spastic equinus, nonspastic equinus, talar dome osteochondral defect, tarsal tunnel syndrome, plantar fasciitis, pes planovalgus, pes cavovarus, peroneal tendinosis, lateral ligament complex pathology, Morton neuroma, plantar plate tear, and metatarsophalangeal joint instability. Computer-generated three-dimensional models are included with many of the procedures to provide a more global view of the surgical anatomy. Correlation with intraoperative photographs is made when available. When appropriate, discussion of postoperative complications, including entities such as infection and failure of graft integration, is presented, although a comprehensive review of postoperative complications is beyond the scope of this article. Notably absent from the current review are some common foot and ankle procedures including hallux valgus and hammertoe corrections, as these are more often evaluated radiographically than with cross-sectional imaging. ©RSNA, 2016.

Rice Body Formation Within a Peri-Articular Shoulder Mass.

Most commonly associated with chronic inflammatory conditions, rice bodies represent an uncommon, nonspecific, often intra-articular inflammatory process. Presumably, rice bodies represent the sequelae of microvascular infarcts of the joint synovium. However, rice bodies have been seen in pleural fluid, in the setting of bursitis, and within the tendon sheath. The etiology and prognostic significance of rice bodies are not clear. MRI is the diagnostic imaging modality of choice for the evaluation of rice body formation. Here we present a case of a 28-year-old female with a history of rheumatoid arthritis (RA) who presented to her primary care physician with a palpable mass around her right shoulder which was presumed to be a lipoma. An initial ultrasound showed a fluid filled structure with internal debris. Subsequent MRI evaluation was confirmatory for subacromial-subdeltoid bursitis with rice body formation. The salient point of this report is to highlight the importance of patient-specific differential diagnosis. While lipomas are a very common benign soft tissue tumor, patients with RA often have disease-specific sequelae that should be included in the diagnostic deliberation. Thus, when ordering diagnostic testing for patients with a palpable mass and rheumatoid arthritis, MRI--possibly preceded by conventional radiography--is the most appropriate diagnostic algorithm.

Synovial cutaneous fistula complicating a reverse total shoulder arthroplasty.

Reverse total shoulder arthroplasty is becoming a common form of shoulder arthroplasty that is often performed in the setting of rotator cuff pathology. Infection is a rare complication but is more common in reverse total shoulder arthroplasty than in hemiarthroplasty or anatomic total shoulder arthroplasty. We present the case of a 69-year-old patient with a reverse total shoulder arthroplasty who presented with purulent drainage from the skin of his anterior shoulder. Computed tomography arthrogram confirmed the presence of a synovial cutaneous fistula. Synovial cutaneous fistula is a rare variant of periprosthetic infection that, to our knowledge, has not been described previously in the setting of a reverse total shoulder arthroplasty. Computed tomography arthrogram proved to be a reliable method for confirming the diagnosis and was used for operative planning to remove the hardware.