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.

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.

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.

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.

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.

Osteosarcoma of the Foot.

A 40-year-old man presented with a large and painful right foot mass. The patient reported a history of a recurrent right foot mass treated elsewhere with 3 prior surgical excisions.

Myositis Ossificans in the Thigh of a Lacrosse Player.

An 18-year-old man presented with mid left thigh pain after sequential lacrosse injuries 1 month and 2 weeks prior. Physical examination was significant for a tender mass in the mid left thigh.