Akira M. Murakami

Preoperative Diagnosis of Infection in Patients with Nonunions

BACKGROUND The surgical treatment of a fracture nonunion is complicated in the presence of infection. The purpose of the present study is to report on the utility of a standardized protocol to rule out infection in high-risk patients and to evaluate the efficacy of each component of the protocol. METHODS A single protocol of preoperative laboratory tests (white blood-cell count, C-reactive protein level, and erythrocyte sedimentation rate) and a combined white blood cell/sulfur colloid scan were performed for patients with a high risk of fracture nonunion. Infection was diagnosed on the basis of positive intraoperative cultures, evidence of gross infection at the time of the procedure, or evidence of gross infection during the immediate postoperative period. With use of infection as the end point, univariate analysis and multiple logistic regression analysis were used to compare tests. A risk stratification method was used to combine tests. RESULTS Ninety-three patients with ninety-five nonunions were evaluated. Thirty of the ninety-five nonunions were ultimately diagnosed as being infected. With use of a combination of elevated white blood-cell count, erythrocyte sedimentation rate, and C-reactive protein level and a positive scan, the predicted probabilities of infection associated with zero, one, two, and three positive tests were 18%, 24%, 50%, and 86%, respectively. With the elimination of the nuclear scan, the predicted probabilities for zero, one, two, and three risk factors were 20%, 19%, 56%, and 100%. CONCLUSIONS The erythrocyte sedimentation rate and the C-reactive protein level were both independently accurate predictors of infection. Use of a risk stratification method showed that the likelihood of infection increased with each additional positive test. A combined white blood cell/sulfur colloid scan was the least predictive method of revealing infection and is not cost effective, even as part of a stratification scheme. LEVEL OF EVIDENCE Diagnostic level III. See instructions for authors for a complete description of levels of evidence.

Active extravasation of the abdomen and pelvis in trauma using 64MDCT

The objective of this study was to determine the clinical and management implications of the finding of active extravasation in blunt or penetrating trauma patients evaluated with abdomino-pelvic computed tomography (CT) using 64MDCT technology. This HIPAA compliant, retrospective study was IRB-approved, and the need for consent was waived. All adult patients scanned with 64MDCT who sustained blunt or penetrating abdomino-pelvic trauma and had findings of active extravasation at our Level I trauma center during a 30-month period were included. Two radiologists reviewed all abdomino-pelvic CT scans and characterized the active hemorrhage by location, extent, and attenuation on all available phases of imaging. Subsequent therapy and disposition were determined by reviewing the patients’ medical records. The relationship between the location of a source of extravasation and subsequent clinical outcome was evaluated using Fischer’s exact test. The relationship between the size and attenuation of the active hemorrhage and patient outcome were compared using the Wilcoxon rank sum test. One hundred and twenty-five patients with active extravasation were included. Patients with solid organ or pelvic injuries that were managed conservatively or had a negative digital subtraction angiogram had statistically significant smaller areas of active extravasation when compared to those that required intervention or died. When the attenuation values of extravasation are normalized to the intravascular attenuation achieved after intravenous contrast injection, no significant differences were seen based on subsequent clinical outcome. Based on location, those patients with solid organ, gastrointestinal/mesenteric, and pelvic sources of bleeding showed statistically significant higher likelihood of requiring subsequent intervention or dying, compared with those patients with subcutaneous, intramuscular, or retroperitoneal sources of active extravasation who were more likely to be managed conservatively (p < 0.0001, p = 0.005, p = 0.006, respectively). In blunt and penetrating trauma patients evaluated using 64MDCT technology, the location and size of the region of active extravasation are predictive of the type of subsequent clinical management. Normalized attenuation values of the active extravasation, however, are not predictive of subsequent management.

Scapholunate advanced collapse: a pictorial review

Scapholunate advanced collapse (SLAC) is the most common cause of osteoarthritis involving the wrist. Along with clinical investigation, radiological studies play a vital role in the diagnosis of SLAC wrist. Given that the osteoarthritic changes that are seen with SLAC occur in a predictable progressive pattern, it is important to understand the pathological evolution of SLAC to be able to recognise the associated progressive imaging findings seen with this disease process. Focusing on radiological findings, this article provides a pictorial review of the anatomy of the scapholunate interosseous ligament as well as the common terminology and biomechanical alterations seen in the pathway leading to the development of SLAC arthropathy. We will then discuss two additional common causes of SLAC wrist and their imaging findings, namely scaphoid non-union advanced collapse and calcium pyrophosphate dehydrate disease. In addition, we will provide a brief overview of the current treatment options of these pathological entities.Teaching Points• SLAC is the most common cause of osteoarthritis involving the wrist.• Arthritic changes of SLAC occur in a predictable progressive pathological and radiographic pattern.• Imaging is key for diagnosing, monitoring progression and assessing post-treatment changes of SLAC.

Multimodality Imaging of Foreign Bodies of the Musculoskeletal System

OBJECTIVE The purpose of this article is to clarify the most relevant points in managing suspected foreign bodies of the musculoskeletal system on the basis of a literature review and published reports with cases to illustrate each type on different imaging modalities. CONCLUSION Foreign bodies of the musculoskeletal system are a common problem in emergency departments, with more than a third missed in the initial clinical evaluation. These retained objects may result in various complications and also offer fertile ground for litigation.

Rotator Cuff Tear Arthropathy: Pathophysiology, Imaging Characteristics, and Treatment Options.

OBJECTIVE The purpose of this article is to review the biomechanical properties of the rotator cuff and glenohumeral joint and the pathophysiology, imaging characteristics, and treatment options of rotator cuff tear arthropathy (RCTA). CONCLUSION Although multiple pathways have been proposed as causes of RCTA, the exact cause remains unclear. Increasing knowledge about the clinical diagnosis, imaging features, and indicators of severity improves recognition and treatment of this pathologic condition.

The Diagnostic and Therapeutic Role of Imaging in Postoperative Complications of Esophageal Surgery

Esophageal surgeries are frequently employed in the management of gastrointestinal reflux disease and esophageal carcinoma. Imaging, in the form of computed tomography and fluoroscopy, is commonly utilized to evaluate for postoperative complications such as anastomotic leaks, abscess formation, pneumothorax, and pleural effusion. An understanding of both esophageal anatomy and the most commonly performed surgical techniques facilitates the diagnosis of these complications and governs their potential computed tomography-guided treatment.

Magnetic Resonance Imaging of Nontraumatic Musculoskeletal Emergencies

Many pathologies of the musculoskeletal system involve nontraumatic causes. MR imaging is used in the diagnosis because of its high sensitivity and specificity compared with other modalities. Osteomyelitis, osteonecrosis of the femoral head, and stress fractures are pathologies of bone where early diagnosis and intervention usually lead to an improved outcome. Joint aspiration and culture is the standard for diagnosing septic arthritis. MR imaging can support the diagnosis and allows evaluation for adjacent abscess and osteomyelitis. Early in the disease process, necrotizing fasciitis may not be clinically suspected and imaging may provide the first indication of the presence of this potentially deadly infection.

Acute Radiologic Manifestations of America’s Opioid Epidemic

The United States is in the midst of an opioid use epidemic, which has severe medical, social, and economic consequences. Addictions to and abuse of prescription and illicit opioids are increasing, and emergency department radiologists are increasingly being faced with the task of examining patients who present with opioid-related complications. These complications may be the result of direct drug toxicity or nonsterile injection of the drugs. Neurologic, musculoskeletal, cardiopulmonary, genitourinary, and gastrointestinal complications may be evident at diagnostic imaging in emergent settings. Heroin-induced leukoencephalopathy, cerebral septic emboli, mycotic arterial aneurysms, soft-tissue infections, and infective endocarditis are some of the conditions that patients may be found to have after they present to the emergency department. In this article, the above topics, including clinical features, pathophysiology, imaging findings, and treatment options, are reviewed. Recognizing the limitations of diagnostic imaging modalities that are available to radiologists is equally important, as some conditions can be successfully diagnosed after the initial triage-for example, transesophageal echocardiography can be performed to diagnose infective endocarditis. The emergency department radiologist may be responsible for identifying acute conditions, which can be life threatening. Some of the more common emergent opioid-related conditions and complications are reviewed, with specific emphasis on cases in which emergency department radiologists encounter conditions for which additional expertise is required. Becoming familiar with the conditions directly related to the current opioid epidemic will enable the diagnosis of these entities in a timely and accurate manner. ©RSNA, 2018.

Understanding Magnetic Resonance Imaging of Knee Cartilage Repair: A Focus on Clinical Relevance

The aims of this review article are (a) to describe the principles of morphologic and compositional magnetic resonance imaging (MRI) techniques relevant for the imaging of knee cartilage repair surgery and their application to longitudinal studies and (b) to illustrate the clinical relevance of pre- and postsurgical MRI with correlation to intraoperative images. First, MRI sequences that can be applied for imaging of cartilage repair tissue in the knee are described, focusing on comparison of 2D and 3D fast spin echo and gradient recalled echo sequences. Imaging features of cartilage repair tissue are then discussed, including conventional (morphologic) MRI and compositional MRI techniques. More specifically, imaging techniques for specific cartilage repair surgery techniques as described above, as well as MRI-based semiquantitative scoring systems for the knee cartilage repair tissue—MR Observation of Cartilage Repair Tissue and Cartilage Repair OA Knee Score—are explained. Then, currently available surgical techniques are reviewed, including marrow stimulation, osteochondral autograft, osteochondral allograft, particulate cartilage allograft, autologous chondrocyte implantation, and others. Finally, ongoing research efforts and future direction of cartilage repair tissue imaging are discussed.

Radiographic Evaluation of Patients with Anterior Shoulder Instability

Purpose of ReviewInjuries to the labrum, joint capsule (in particular the inferior glenohumeral ligament), cartilage, and glenoid periosteum are associated with anterior shoulder instability. The goal of this review is to provide common radiographic images and findings in patients with anterior shoulder instability. Furthermore, we will demonstrate the best methods for measuring anterior glenoid bone loss.Recent FindingsMagnetic resonance (MR) imaging is highly relied upon for evaluating anterior shoulder instability and can diagnose soft tissue injuries with high sensitivity. While 3D computed tomography (CT) scan has been considered the optimal tool for evaluating osseous defects, certain MR imaging sequences have been shown to have similar diagnostic accuracy. Repair of Bankart lesions is critical to stabilizing the shoulder, and in the recent years, there has been an increasing focus on imaging to accurately characterize and measure glenoid bone loss to properly indicate patients for either arthroscopic repair or anterior bony reconstruction. Furthermore, Hill-Sachs lesions are commonly seen with shoulder instability, and importance must be placed on measuring the size and depth of these lesions along with possible engagement, as these factors will dictate management.SummaryThe labral-ligamentous complex and rotator cuff are primary stabilizers of the shoulder. With anterior shoulder instability, the labrum is frequently injured. MRI with an arthrogram or provocative maneuvers is the gold standard for diagnosis. Various imaging modalities and methods can be performed to identify and measure Bankart and Hill-Sachs lesions, which can then be used for surgical planning and treating shoulder instability.