The G2 research R.I.P. fragmenting bullet-radiographic features of a recently encountered projectile.

Gunshot wounds (GSWs) are an important cause of disability and death in the USA. Although radiography is limited in its ability to detect bullet types, a projectile introduced during the last decade, the R.I.P. bullet by G2 Research, consists of a base slug connected to 6 to 8 sharp trocars designed to diverge within soft tissue following impact, resulting in what we believe to be a unique imaging appearance that can be confusing to those not familiar with this particular projectile. Furthermore, this bullet is 100% copper, which may allow for safe imaging with magnetic resonance imaging if correctly identified prior to scanning.

Soft-Tissue Tumors of the Hand-Imaging Features.

Imaging studies of the hands and fingers are common, and radiologists are generally comfortable with traumatic and degenerative conditions which arise frequently in daily practice. However, a variety of common and uncommon soft-tissue tumors also occur in the hand, the appropriate diagnosis of which can be a source of confusion for both clinicians and radiologists. These lesions often have overlapping imaging characteristics; however, a structured approach can help provide a focused differential diagnosis and impact further workup and management. We discuss several such tumors, categorizing them as cystic-appearing, noncystic masses along tendons and aponeuroses, adipocytic tumors, vascular lesions, and miscellaneous lesions with imaging features that can aid diagnosis.

Spectrum of Voriconazole-Induced Periostitis With Review of the Differential Diagnosis.

OBJECTIVE: Voriconazole is an antifungal medication used primarily for the treatment of Candida and Aspergillus infections. A fairly newly described side effect of long-term voriconazole use is periostitis. The purpose of this article is to describe the main differential consideration-hypertrophic osteoarthropathy-and other differential diagnoses, including venous stasis, thyroid acropachy, and hypervitaminosis A. CONCLUSION: With knowledge of imaging appearance, clinical manifestations, and outcomes, radiologists can make an accurate diagnosis of voriconazole-induced periostitis, and clinical teams can initiate appropriate management.

Update on Imaging of Knee Arthroplasties: Normal Findings and Hardware Complications.

Total knee arthroplasty (TKA) is the most common joint replacement performed. This article reviews the normal appearance of TKA including the most common types of arthroplasties as well as complications. Common complications at the present time are infection, aseptic loosening, and instability. Rarer complications such as polyethylene wear, periprosthetic fracture, and soft tissue pathology are also discussed. Although the mainstay of imaging is radiographs, newer techniques in TKA imaging such as computed tomography and magnetic resonance imaging are also reviewed.

From tumor to trauma: etiologically deconstructing a unique differential diagnosis of musculoskeletal entities with high signal intensity on T1-weighted MRI.

OBJECTIVE: This article reviews the neoplastic and nonneoplastic abnormalities of the musculoskeletal system that contain high signal intensity on T1-weighted MRI. The physical properties accounting for the increased signal intensity as well as the key clinical and imaging characteristics of each entity are discussed. CONCLUSION: Recognition of high signal intensity within musculoskeletal lesions on T1-weighted MRI can limit the differential diagnosis and can also have important clinical implications.

Infarct-Associated Bone Sarcomas: Multimodality Imaging Findings.

OBJECTIVE: The objective of our study was to characterize infarct-associated bone sarcoma and its imaging features. MATERIALS AND METHODS: Our databases were searched for instances of sarcoma arising in association with osteonecrosis. Demographic and imaging data were recorded. The imaging studies of 258 patients with sarcomas were reviewed to determine whether underlying osteonecrosis was present. Radiographic and MRI studies of patients with bone infarction were reviewed to categorize the various appearances of infarction and to determine if sarcomas tended to arise in a particular pattern. A literature review was performed. RESULTS: Nine infarct-associated bone sarcomas were found in eight patients: seven malignant fibrous histiocytomas (MFHs) and two osteosarcomas. All occurred in the femur or tibia; multifocal infarction was documented in all patients except one. Sarcomas were commonly associated with a so-called "mature"-type pattern of osteonecrosis-that is, with well-defined calcified margins. Osteolysis of infarct-associated MFHs was often overlooked at initial presentation and was often detected only after pathologic fracture. CT and MRI revealed cortical penetration in all cases; infarct margin disruption was evident, but preservation of fat within the infarct was typical. Increased radiotracer activity with relative central photopenia was characteristic of large infarct-associated bone sarcomas on scintigraphy. All lesions, including those treated at our institution and those found in the literature, were metaphyseal or diaphyseal, and although epiphyseal extension of sarcoma from a metadiaphyseal infarct was common, no purely epiphyseal lesions were encountered. CONCLUSION: Radiologists must remain vigilant for this rare occurrence, especially in patients with new pain in an area of known bone infarction.

Imaging Diagnosis of Solitary Tumors of the Phalanges and Metacarpals of the Hand.

OBJECTIVE: Tumors and tumorlike lesions of the tubular bones of the hand, often incidentally discovered lesions, present a unique but challenging differential diagnosis. CONCLUSION: Imaging, including both radiography and cross-sectional imaging, can allow the radiologist to generate a clinically useful differential diagnosis based on the distinguishing features of these entities. Recognition of these lesions is important because clinical management and treatment by orthopedic oncologists vary depending on the diagnosis.

Osteoma of long bone: an expanding spectrum of imaging findings.

Osteoma of long bone is an extremely rare, benign bone-forming surface lesion with the largest published case series consisting of only 14 patients. The most important and often most difficult lesion to differentiate from osteoma of long bone radiographically is parosteal osteosarcoma, which is a rare, low-grade surface osteosarcoma with the potential for dedifferentiation. Reports of imaging studies of osteoma of long bone depict a well-defined ossified mass arising from the surface of the diaphysis or metadiaphysis of a long bone. A characteristic feature is the homogeneity of the mass, with uniform density near or equal to that of cortical bone from the base of the lesion to its periphery. The 45-year-old female in this case presented with left hip fullness and was subsequently found to have a proximal femoral osteoma, which was unique in that it contained large fatty marrow spaces that corresponded to bands of relatively low density on plain radiography and computed tomography, giving it a heterogeneous appearance atypical of osteoma of long bone. Furthermore, the osteoma reported here was associated with a small but separate nodular focus of ossification in the adjacent soft tissue. These findings led to a presumptive diagnosis of parosteal osteosarcoma with a local soft tissue metastasis or satellite nodule resulting in radical resection of the tumor. Definitive diagnosis of osteoma was made on histology of both the parent lesion and ossified nodule as no neoplastic spindle cell proliferation was present to establish a diagnosis of low-grade osteosarcoma. This represents, to the best of our knowledge, the first such presentation of osteoma of long bone.

Cubonavicular Coalition: Magnetic Resonance Imaging Findings and Associated Pathology of a Rarely Reported Condition in 27 Patients.

RATIONALE AND OBJECTIVES: (1) Describe multimodality imaging of cubonavicular coalition (CNC) with magnetic resonance imaging (MRI) focus, (2) evaluate CNC associated foot and ankle pathology, (3) examine clinical presentation/symptoms associated with CNC, (4) record CNC treatment. MATERIALS AND METHODS: Retrospective Institutional Review Board (IRB) approved study. Picture Archiving and Communication System (PACS) databases searched for CNC. Final study population: 34 cases in 27 patients. Each CNC was reviewed for: coalition type (osseous versus non-osseous- cartilaginous versus fibrous), tendon and ligament pathology, bone marrow edema at CNC and adjacent joints, presence and severity of degenerative changes at CNC and adjacent joints, fractures, additional coalitions, laterality, and pes planus. MRI planes and radiographic views on which coalitions were best identified were recorded. Each CNC EMR was reviewed for: symptoms, trauma, management, patient demographics. Inter-reader reliability was performed for type of non-osseous coalition. RESULTS: Final cohort included 34 cases in 27 patients (average age: 34.7, range: 10-76; 71% female). No CNC was completely osseous. On MRI, 89.5% of coalitions were non-osseous and 5.3% were partially osseous. 76.5% of patients had referable symptoms including pain, limited motion, inability to bear weight. 23.5% of patients were surgically managed/pathologically proven. On MRI, 36.8% of patients had tendon pathology, 52.6% had ligamentous pathology, 100% had bone marrow edema-like signal abnormality about the CNC, and 88.2% had CNC degenerative changes. There was bone marrow edema-like signal abnormality at bones adjacent to the CNC in 52.6% and adjacent joint degenerative disease present in 50%. CNC was best identified on oblique radiographs and axial MRI. Inter-reader reliability for non-osseous coalition type was poor, Cronbach's alpha 0.554. CONCLUSION: CNC is subtle and findings of osteoarthritis or bone marrow edema-like about the cubonavicular articulation should raise suspicion for underlying coalition.

Musculoskeletal manifestations of neurofibromatosis type 1.

OBJECTIVE: We will describe and illustrate various musculoskeletal manifestations of neurofibromatosis type 1 (NF1) encountered on imaging studies. CONCLUSION: Because NF1 is one of the most common genetic disorders, radiologists should be familiar with its imaging manifestations.

Pitfalls in MR image interpretation prompting referrals to an orthopedic oncology clinic.

Patients referred to the authors' hospital for evaluation on suspicion of a bone or soft-tissue malignancy frequently present to the Orthopaedic Oncology Clinic with magnetic resonance (MR) images that show typical features of nonmalignant or nonneoplastic entities. The purpose of this article is to review the benign entities that may be mistaken by the radiologist for a malignancy and thus lead to needless referral to an orthopedic oncologist. Normal hematopoietic marrow and marrow edema due to a stress reaction may mimic a neoplasm at MR imaging, but knowledge of the typical patterns and locations of these features allows an accurate radiologic interpretation. The MR imaging appearance of osteonecrosis, Paget disease, benign bone lesions, and rheumatologic conditions may be confusing; in such circumstances, radiographic findings may help formulate a correct diagnosis. Knowledge of the common locations and appearances of bursae and ganglia is necessary so that radiologists do not misinterpret these benign entities as soft-tissue sarcomas. Soft-tissue trauma and inflammation also may mimic tumors at MR imaging, but a familiarity with the imaging patterns of nonneoplastic change in muscle allows the avoidance of misinterpretation. The clinical history, as always, is an important component of proper diagnosis. The radiologist can be especially useful to both the clinician and the patient by recognizing entities that are highly unlikely to represent malignancy and by confidently reporting those entities as benign, thereby sparing the patient an unnecessary trip to the orthopedic oncologist.

Use of Hyperlinks in PowerPoint Presentations as an Educational Tool.

PowerPoint software (Microsoft, Redmond, WA) has become a popular tool for creating and displaying electronic presentations. The "hyperlink" function in PowerPoint allows users to advance from one slide to another slide in the presentation when they click on a predetermined word, shape, or image, thereby allowing for a more dynamic and interactive experience than can be obtained with serial presentation of slides alone. The objective of this article is to provide a tutorial describing the necessary steps to create hyperlinks and incorporate them in a variety of ways into a PowerPoint presentation. Hyperlinks can turn a passive learning experience into an active one by allowing the participant to become more engaged with the presentation.

Conventional radiographic evaluation of athletic injuries to the hand.

Athletic injuries to the hand are common and encompass a diverse spectrum of injuries. These injuries can include fractures, soft tissue injuries, or both. Athletic injuries to the hand can be due to a variety of mechanisms and can be seen with a variety of sports. Prompt attention and accurate diagnosis should be provided to patients with athletic injuries to the hand to allow for appropriate treatment and to prevent serious complications that may preclude further athletic activity. This article discusses the radiographic evaluation of hand fractures seen in athletes and presents brief descriptions of the clinical management of these injuries.

Musculoskeletal aspiration procedures.

With advances in imaging technology, there has been a significant increase in the number and range of interventional musculoskeletal image-guided procedures. One of the most commonly performed image-guided musculoskeletal interventions is the diagnostic and therapeutic percutaneous aspiration and drainage of multiple types of intra-articular, juxta-articular, and intramuscular pathologic fluid collections. These procedures may be performed under fluoroscopic, ultrasound, computed tomography, or even magnetic resonance guidance depending on the location to be accessed, type of pathology, patient characteristics, and operator preference. Musculoskeletal image-guided aspiration and drainage procedures are minimally invasive and generally very safe while offering valuable diagnostic information as well as therapeutic benefit. This article focuses on the appropriate indications, contraindications, and general technique for accessing the major joints via imaging guidance. For each joint, we discuss pertinent anatomy, appropriate imaging modalities, and preferred approaches to gaining intra-articular access. Additionally, the article discusses some of the more frequently encountered juxta-articular and intramuscular fluid collections that can be accessed and aspirated via percutaneous intervention, with mention of the importance of recognizing extremity sarcomas that can mimic these benign collections.

Multifocal metachronous giant cell tumor in a 15-year-old boy.

We report a case of multifocal metachronous giant cell tumor (GCT) that involved the fibula, tibia, and sacrum of a 15-year-old boy. Multifocal GCT of bone presenting in children is an exceedingly rare phenomenon; however, there is evidence that multifocal GCT presents, on average, at a younger age than solitary GCT. Pediatric radiologists should be aware of this when encountering a single lesion with characteristic radiographic features of GCT and when encountering multiple lytic skeletal lesions.