Multimodality Imaging of Foreign Bodies: New Insights into Old Challenges.

Traumatic wounds and lacerations are a common reason for patients to present to emergency departments, with retained foreign bodies (FBs) accounting for 7%-15% of cases, particularly those involving the extremities. These retained materials result in a granulomatous tissue response known as an FB reaction, a pathologic attempt to isolate the FB from the host. The most common FB materials are glass, metal, and wood, but other compositions can also be found, such as plastic and animal-derived materials. Clinical history, physical examination, and wound exploration are essential in investigation of retained material but are not sufficient to exclude an FB, and additional investigation is required. Imaging evaluation is a useful tool to help depict and locate an FB, assess possible complications, and guide removal. Conventional radiography, the first-line method in this scenario, is a widely available low-cost depiction method that has good sensitivity for depicting FBs. If the retained material is not depicted at conventional radiography, US can be performed. US is highly sensitive in depicting both radiolucent and radiopaque FBs in superficial locations. For deeper objects, CT may be necessary. MRI is the best imaging modality to delineate local soft-tissue and osseous complications. Retained FBs can result in early and delayed complications, with infection being the most frequent complication. To avoid preventable morbidities related to FBs, radiologists should be familiar with imaging findings and provide essential information to help the attending physician treat each patient. Online supplemental material is available for this article. ©RSNA, 2020.

Radiologic Manifestations of Musculoskeletal Sarcoidosis.

PURPOSE OF REVIEW: The purpose of this review article is to present the spectrum of abnormalities and multi-modality imaging evaluations in patients with musculoskeletal sarcoidosis. RECENT FINDINGS: The articular manifestations of sarcoidosis are difficult to distinguish from those of the other inflammatory and degenerative arthropathies, and the muscular lesions in sarcoidosis are generally clinically silent and therefore often missed. Magnetic resonance imaging has shown these manifestations to be very common in active sarcoidosis, and should thus be included in the screening if musculoskeletal sarcoidosis is suspected. The clinician should consider magnetic resonance imaging for the evaluation of patients with sarcoidosis who have unexplained osteoarticular complaints if standard radiographs are negative. Furthermore, radiologists should include sarcoidosis in the differential diagnosis of musculoskeletal disease detected at magnetic resonance imaging in the appropriate clinical setting.

Whole-Body Imaging of Multiple Myeloma: Diagnostic Criteria.

Multiple myeloma (MM) is a clonal plasma cell proliferative disorder characterized by primary infiltration of bone marrow and excessive production of abnormal immunoglobulin. This disease is the second most common hematologic malignancy (after lymphoma), and its spectrum of characteristic features are widely known by the acronym CRAB (hypercalcemia, renal impairment, anemia, and bone lesions). Traditionally, the diagnosis and treatment of MM have been triggered by clear end-organ damage. However, owing to recently introduced treatment options that can extend patient survival and the increasing recognition of biomarkers that can be used to identify patients at high risk of progression to active disease, the diagnostic criteria have been revised. Bone disease is one of the most prominent features of MM, and imaging has an important role in diagnosis and follow-up, with each whole-body imaging modality having different indications in distinct disease situations. Skeletal survey has been the standard imaging procedure used during the past decade, but it should no longer be used unless it is the only option. Whole-body low-dose CT is a reasonable and cost-effective initial imaging approach. Whole-body MRI is the most sensitive technique for detecting bone involvement and assessing painful complications. PET/CT is the best tool for evaluating treatment response. The importance of radiologists has increased in this scenario. Therefore, to properly assist hematologists and improve the care of patients with MM, it is essential that radiologists know the updated diagnostic criteria for MM, indications for and limitations of each imaging option, and recommendations for follow-up. Online supplemental material is available for this article. ©RSNA, 2019.

Osteoid osteoma: the great mimicker.

Osteoid osteoma is a painful, benign and common bone tumor that is prevalent in young adults. The typical clinical presentation consists of pain that becomes worse at night and is relieved by nonsteroidal anti-inflammatory drugs. The most common imaging finding is a lytic lesion, known as a nidus, with variable intralesional mineralization, accompanied by bone sclerosis, cortical thickening and surrounding bone marrow edema, as well as marked enhancement with intravenous contrast injection. When the lesion is located in typical locations (intracortical bone and the diaphyses of long bones), both characteristic clinical and radiological features are diagnostic. However, osteoid osteoma is a multifaceted pathology that can have unusual presentations, such as intraarticular osteoid osteoma, epiphyseal location, lesions at the extremities and multicentric nidi, and frequently present atypical clinical and radiological manifestations. In addition, many conditions may mimic osteoid osteoma and vice versa, leading to misdiagnosis. Therefore, it is essential to understand these musculoskeletal diseases and their imaging findings to increase diagnostic accuracy, enable early treatment and prevent poor prognosis.