ACR Appropriateness Criteria® Chronic Extremity Joint Pain-Suspected Inflammatory Arthritis, Crystalline Arthritis, or Erosive Osteoarthritis: 2022 Update.

Evaluation for suspected inflammatory arthritis as a cause for chronic extremity joint pain often relies on imaging. It is essential that imaging results are interpreted in the context of clinical and serologic results to add specificity because there is significant overlap of imaging findings among the various types of arthritis. This document provides recommendations for imaging evaluation of specific types of inflammatory arthritis, including rheumatoid arthritis, seronegative spondyloarthropathy, gout, calcium pyrophosphate dihydrate disease (or pseudogout), and erosive osteoarthritis. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Radiologists' Diagnostic Performance in Differentiation of Rickets and Classic Metaphyseal Lesions on Radiographs: A Multicenter Study.

BACKGROUND. Despite evidence supporting the specificity of classic metaphyseal lesions (CML) for the diagnosis of child abuse, some medicolegal practitioners claim that CML result from rickets rather than trauma. OBJECTIVE. The purpose of this study was to evaluate radiologists' diagnostic performance in differentiating rickets and CML on radiographs. METHODS. This retrospective seven-center study included children younger than 2 years who underwent knee radiography from January 2007 to December 2018 and who had either rickets (25-hydroxyvitamin D level < 20 ng/mL and abnormal knee radiographs) or knee CML and a diagnosis of child abuse from a child abuse pediatrician. Additional injuries were identified through medical record review. Radiographs were cropped and zoomed to present similar depictions of the knee. Eight radiologists independently interpreted radiographs for diagnoses of rickets or CML, rated confidence levels, and recorded associated radiographic signs. RESULTS. Seventy children (27 girls, 43 boys) had rickets; 77 children (37 girls, 40 boys) had CML. Children with CML were younger than those with rickets (mean, 3.7 vs 14.2 months, p < .001; 89.6% vs 5.7% younger than 6 months; 3.9% vs 65.7% older than 1 year). All children with CML had injuries in addition to the knee CML identified at physical examination or other imaging examinations. Radiologists had almost perfect agreement for moderate- or high-confidence interpretations of rickets (κ = 0.92) and CML (κ = 0.89). Across radiologists, estimated sensitivity, specificity, and accuracy for CML for moderate- or high-confidence interpretations were 95.1%, 97.0%, and 96.0%. Accuracy was not significantly different between pediatric and nonpediatric radiologists (p = .20) or between less experienced and more experienced radiologists (p = .57). Loss of metaphyseal zone of provisional calcification, cupping, fraying, and physeal widening were more common in rickets than CML, being detected in less than 4% of children with CML. Corner fracture, bucket-handle fracture, subphyseal lucency, deformed corner, metaphyseal irregularity, and subperiosteal new bone formation were more common in CML than rickets, being detected in less than 4% of children with rickets. CONCLUSION. Radiologists had high interobserver agreement and high diagnostic performance for differentiating rickets and CML. Recognition that CML mostly occur in children younger than 6 months and are unusual in children older than 1 year may assist interpretation. CLINICAL IMPACT. Rickets and CML have distinct radiographic signs, and radiologists can reliably differentiate these two entities.

Pattern Recognition: A Mechanism-based Approach to Injury Detection after Motor Vehicle Collisions.

Motor vehicle collisions cause substantial mortality, morbidity, and expense worldwide. Certain types of injuries are more likely to result from frontal versus side-impact collisions, and knowledge of these specific patterns and why they occur aids in accurate and efficient diagnosis of traumatic injuries. Although the proper use of seat belts decreases crash-related mortality during frontal impact, certain injury patterns to the torso are directly attributed to restraint use. The spectrum of seat belt-related injuries ranges from mild skin and soft-tissue contusions to traumatic bowel injuries and unstable spine injuries that require surgery. Impact with the steering wheel or windshield during a frontal crash can cause characteristic injuries to the head, neck, torso, and distal upper extremity. Steering wheel deformity is an independent predictor of serious thoracic and abdominal injury among front-seat passengers. Impact of a flexed knee with the dashboard during a frontal collision can cause knee, thigh, and hip injuries. Distal lower extremity injuries are encountered frequently when the floorboard is driven into the foot. Lateral impact crashes often result in traumatic brain, thoracic, abdominal, and pelvic injuries, which are more often fatal to occupants on the side of the impact. The specific mechanism-based injury patterns are reviewed to establish a structured systematic search pattern that enables the radiologist to identify traumatic injuries with greater accuracy and speed, thereby improving the care of patients who experience acute trauma. ©RSNA, 2019 See discussion on this article by Ballard and Mellnick .

The inferior vena cava: a pictorial review of embryology, anatomy, pathology, and interventions.

The inferior vena cava (IVC) is the largest venous conduit below the diaphragm. Although this structure is often overlooked both clinically and radiographically, it can be involved in many different pathologic processes. A thorough understanding of the IVC will assist the radiologist in recognizing anatomic variants, identifying abnormalities, and providing accurate differential diagnoses. In this comprehensive pictorial review of the IVC, we depict embryology behind anatomic variants, present a wide range of pathology with a focus on diagnostic imaging, and describe relevant endovascular interventions.

Head and Neck Injuries: Special Considerations in the Elderly Patient.

Traumatic injuries to the head and neck are common in the elderly, which is a rapidly growing sector of the American population. Most injuries result from low-energy falls and therefore might be at risk for delayed presentation and undertriage. Imaging, particularly with computed tomography, plays a vital role in the evaluation of traumatic head and neck injuries in geriatric patients. A thorough understanding of the differing patterns of trauma in the elderly patient and the factors that are associated with poorer outcomes is essential.

Distal clavicle fracture radiography and treatment: a pictorial essay.

Fractures of the distal clavicle represent 15-30% of all clavicle fractures. The local osseoligamentous anatomy and deforming forces result in increased risk of delayed union and nonunion than fractures in other parts of the clavicle. These factors also contribute to challenges in fracture repair. Understanding these injuries and their imaging features enhances care and ensures patients are directed to appropriate management. We review the anatomy of the distal clavicle and surrounding ligaments, options for radiographic evaluation, relevant classification systems, and current concepts in management. Illustrative examples of specialized views are provided. Pediatric acromioclavicular joint pseudosubluxation is also reviewed, with findings specific to that injury.

Scary gas: pathways in the axial body for soft tissue gas dissection (part I).

Gas is often encountered in abnormal locations in the torso, including within soft tissue compartments, vessels, and bones. The clinical significance of this gas ranges from incidental, benign, and self-limited to aggressive infection requiring immediate surgery. As a result of fascial interconnectivity and pressure differences between compartments, gas can dissect distant from its source. Gas can easily dissect between spaces of the extrapleural thorax, subperitoneal abdomen, deep cervical spaces, and subcutaneous tissues. The pleural and peritoneal cavities are normally isolated but may communicate with the other spaces in select situations. Dissection of gas may cause confusion as to its origin, potentially delaying treatment or prompting unnecessary and/or distracting workup and therapies. The radiologist might be the first to suggest and identify a remote source of dissecting gas when the clinical manifestation alone might be misleading. The purpose of this paper, the first in a three-part series on soft tissue gas, is to explore the various pathways by which gas dissects through the superficial and deep compartments of the torso.

Scary gas: a spectrum of soft tissue gas encountered in the axial body (part II).

Ectopic gas in the mediastinum, subperitoneal abdomen, and superficial soft tissues is concerning and can be seen in the setting of trauma, iatrogenic injuries, infection, and inflammation. It can spread along different dissection pathways and may present remotely from the involved organ as described in part one. Recognition of ectopic gas on imaging and differentiating it from other causes of benign gas is very important as these conditions associated with ectopic gas can lead to rapid patient deterioration and usually require urgent surgery. In part two, the different causes of ectopic and benign gas in the torso are reviewed as well as the imaging features that can help to narrow the differential diagnosis.

Scary gas: intravascular, intracranial, and intraspinal ectopic gas (part III).

While ectopic gas can be a sign of dangerous disease requiring immediate medical or surgical intervention, it can also be an incidental and benign finding. Intravenous gas and spinal vacuum gas are common and almost always benign. Intravascular gas is most often related to instrumentation and, if intraarticular, can cause end-organ ischemia; however, treatment is usually supportive. Pneumocephalus arises from a communication with paranasal sinuses or mastoids more often than from meningeal infection and can usually be managed nonoperatively. In part 3 of this series, the different causes of ectopic gas in the vessels, skull, and spine are reviewed, as are the imaging features that can help to narrow the differential diagnosis.

Beyond decreased bowel enhancement: acute abnormalities of the mesenteric and portal vasculature.

Acute mesenteric ischemia (AMI) is a potentially life-threatening condition with an associated high mortality. Prompt diagnosis is crucial to achieve a favorable outcome. The radiologist plays a central role in the initial evaluation of a patient with suspected AMI. In this pictorial essay, we review the appropriate imaging evaluation of a patient with suspected AMI, and we review both the common and uncommon etiologies of mesenteric ischemia. With each etiology presented, relevant clinical and imaging findings, as well as potential treatments, are reviewed.

Geriatric Trauma: A Radiologist's Guide to Imaging Trauma Patients Aged 65 Years and Older.

Radiologists play an important role in evaluation of geriatric trauma patients. Geriatric patients have injury patterns that differ markedly from those seen in younger adults and are susceptible to serious injury from minor trauma. The spectrum of trauma in geriatric patients includes head and spine injury, chest and rib trauma, blunt abdominal injury, pelvic fractures, and extremity fractures. Clinical evaluation of geriatric trauma patients is difficult because of overall frailty, comorbid illness, and medication effects. Specific attention should be focused on the effects of medications in this population, including anticoagulants, steroids, and bisphosphonates. Radiologists should use age-appropriate algorithms for radiography, computed tomography (CT), and magnetic resonance imaging of geriatric trauma patients and follow guidelines for intravenous contrast agent administration in elderly patients with impaired renal function. Because there is less concern about risk for cancer with use of ionizing radiation in this age group, CT is the primary imaging modality used in the setting of geriatric trauma. Clinical examples are provided from the authors' experience at a trauma center where geriatric patients who have sustained major and minor injuries are treated daily.

Imaging of Urinary System Trauma.

Computed tomography (CT) imaging of the kidney, ureter, and bladder permit accurate and prompt diagnosis or exclusion of traumatic injuries, without the need to move the patient to the fluoroscopy suite. Real-time review of imaging permits selective delayed imaging, reducing time on the scanner and radiation dose for patients who do not require delays. Modifying imaging parameters to obtain thicker slices and noisier images permits detection of contrast extravasation from the kidneys, ureters, and bladder, while reducing radiation dose on the delayed or cystographic imaging. The American Association for the Surgery of Trauma grading system is discussed, along with challenges and limitations.

Acute shoulder trauma: what the surgeon wants to know.

Many excellent studies on shoulder imaging from a radiologic perspective have been published over the years, demonstrating the anatomy and radiologic findings of shoulder trauma. However, it may not always be clear what the surgeon, who bears the responsibility for treating the injured patient, really needs to know about the injury to predict outcomes and plan management. The authors review the relevant osseous, soft-tissue, and vascular anatomy and describe the clinically relevant concepts that affect management. Familiarity with the Neer classification system for proximal humerus fractures can have a significant impact on treatment. The length and displacement of the medial humeral metaphyseal fragment helps predict the risk of ischemia in proximal humerus fractures. The Nofsinger approach for measuring the area of glenoid fossa bone loss can help the surgeon determine the need for surgical repair of a bony Bankart lesion. The size of Hill-Sachs and reverse Hill-Sachs lesions is also an important predictor of stability. The Ideberg classification system for intraarticular fractures of the glenoid fossa, combined with information on instability and joint incongruity, helps determine the need for surgical fixation of glenoid fossa fractures. Awareness of what matters to the surgeon can help radiologists better determine where to focus their attention and efforts when describing acute shoulder trauma.

Current concepts in imaging evaluation of penetrating transmediastinal injury.

Penetrating transmediastinal injuries (TMIs) are injuries that traverse the mediastinum. These injuries are most commonly caused by firearms and knives. The investigation and management algorithms for TMI have undergone changes in recent years due to increasing evidence that computed tomography (CT) in useful in the evaluation of hemodynamically stable TMI patients. Initial investigation of TMI patients depends on the question of hemodynamic stability. In unstable patients, imaging (if any) should be limited to bedside radiography and focused ultrasonography. In hemodynamically stable patients in whom a mediastinal trajectory of injury is suspected, the primary imaging modality after radiography should be multidetector CT. CT is invaluable in the assessment of TMI due to its capacity to depict the injury track as well as demonstrate both direct and indirect signs of organ injury. On the basis of the suspected trajectory and specific findings, radiologists can play an essential role in determining future patient management and investigations for each mediastinal organ, thereby expediting appropriate investigation and treatment and avoiding unnecessary and sometimes invasive tests or surgery. The authors provide an up-to-date and evidence-based approach for the management of hemodynamically unstable and stable patients with suspected TMI, discuss management algorithms and CT protocols, and highlight common and uncommon imaging findings and diagnostic pitfalls associated with vascular, cardiac, esophageal, tracheobronchial, pleural, and pulmonary injuries. Online supplemental material is available for this article.

Variability in management recommendations for incidental thyroid nodules detected on CT of the cervical spine in the emergency department.

PURPOSE: Incidental thyroid nodules are common on CT. Variability in management recommendations for these nodules due to a lack of accepted CT base guidelines has not been demonstrated. METHODS: Consecutive CT cervical spine radiology reports describing thyroid nodules performed in an emergency department from January 1, 2009, to December 31, 2011, were retrospectively reviewed. Number of nodules, nodule size, and type of recommended management were recorded. RESULTS: Three hundred fifteen examinations met the inclusion criteria. The mean study age was 64 ± 20 years. Fifty-eight percent were women. Thirty percent (n = 95) of thyroid nodules measured <10 mm, 20% (n = 63) were ≥10 but <15 mm, 11% (n = 36) were ≥15 but <20 mm, and 15.5% (n = 49) were ≥20 mm. Size was not reported for 22.9% (n = 72). Two hundred twenty-seven recommendations were made in 181 (57.5%) studies. Recommendations were made for 51.6% (49 of 95) of nodules <10 mm, for 52.4% (33 of 63) of those ≥10 but <15 mm, for 83.3% (30 of 36) of those ≥15 but <20 mm, and for 81.6% (40 of 49) of those ≥20 mm. Management was recommended in 40.0% (29 of 72) of nodules with no size reported. Fifty-four percent (123 of 227) of recommendations were for ultrasound, followed by no follow-up recommended (17.2% [39 of 227]), clinical correlation (13.7% [31 of 227]), thyroid serology (6.2% [14 of 227]), clinical follow-up (4.8% [11 of 227]), comparison with prior studies (2.2% [5 of 227]), fine-needle aspiration (1.3% [3 of 227]), and nuclear scintigraphy (0.4% [1 of 227]). Nodule size was significantly associated with the likelihood of recommendation (odds ratio, 1.79; 95% confidence interval, 1.37-2.35). CONCLUSIONS: Management recommendations for incidental thyroid nodules detected on cervical spine CT are made inconsistently, and the type of management recommended is variable.