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.

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.

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 .

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.

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.

Frequency of external iliac artery branch injury in blunt trauma: improved detection with selective external iliac angiography

PURPOSE

To assess the utility of selective external iliac artery (EIA) angiography and the frequency of injury to branches of the EIA in cases of blunt pelvic trauma.

MATERIALS AND METHODS

A retrospective review of pelvic angiograms in 66 patients with blunt pelvic trauma was conducted over a 12-month period. Pelvic and femur fracture patterns were correlated to the presence of EIA injury. Pelvic arteriography was compared versus selective EIA angiography for the detection of arterial injury.

RESULTS

Fifty-four of 66 patients (82%) exhibited pelvic arterial injury or elicited enough suspicion for injury to warrant embolization. Internal iliac artery embolization was performed in 50 of 66 (76%). EIA branch injury was identified in 11 of 66 patients (17%), and 10 were successfully embolized. EIA branch vessel injury was identified more frequently when there was ipsilateral intertrochanteric fracture (P = .07) or ipsilateral ilium fracture (P = .07). The sensitivity of nonselective pelvic angiography in the detection of EIA branch vessel injury was 45%.

CONCLUSIONS

EIA branch injury occurs in a substantial fraction of patients with blunt pelvic trauma who undergo pelvic angiography. Selective EIA angiography should be considered in all patients undergoing pelvic angiography in this situation.

Diaphragmatic hernias: a spectrum of radiographic appearances

Diaphragmatic hernias are common, and although frequently incidental, recognition of both benign and life-threatening manifestations of diaphragmatic hernias is necessary to guide appropriate management. Congenital fetal diaphragmatic hernias, traumatic diaphragmatic rupture, and large symptomatic Bochdalek, Morgagni, and hiatal hernias are typically repaired surgically, while eventration, diaphragmatic slips, and small diaphragmatic hernias do not require intervention or imaging follow-up but should be recognized to avoid confusion with other diagnoses that require additional attention. This pictorial essay will explore the imaging findings and clinical characteristics of these entities.

Hippocampal Volume and the Mini-Mental State Examination in the Diagnosis of Amnestic Mild Cognitive Impairment

OBJECTIVE

The purpose of this study was to examine the diagnostic efficacy of hippocampal volumetry and the Mini-Mental State Examination (MMSE) in differentiating amnestic mild cognitive impairment from the normal changes of aging.

SUBJECTS AND METHODS

The conditions of healthy older persons (n = 17) and persons with amnestic mild cognitive impairment (n = 18) were classified on the basis of results of comprehensive neuropsychological assessment. All subjects underwent MRI at 4 T, including high-resolution coronal T1-weighted images. Hippocampal volume was calculated by tracing right and left hippocampal formations on coronal slices and normalizing by single-slice intracranial area. Receiver operating characteristic analysis and logistic regression analysis were performed to evaluate the diagnostic efficacy of hippocampal volume and the MMSE in differentiating subjects with amnestic mild cognitive impairment from subjects with normal cognitive function.

RESULTS

The mean +/- SE area under the receiver operating characteristics curve (AUC) for left hippocampal volume (0.886 +/- 0.056) was greater than that for right hippocampal volume (0.614 +/- 0.097). The AUC for MMSE score (0.745 +/- 0.085) was intermediate and not statistically different from that of hippocampal volume measurements alone. The AUC for the combination of left hippocampal volume and MMSE score (0.92) was significantly greater than that of MMSE score alone (p < 0.05).

CONCLUSION

In the diagnosis of amnestic mild cognitive impairment, use of left hippocampal volume may be more efficacious than use of right hippocampal volume and may add to the value of routine screening MMSE. Automated hippocampal volumetry may become a useful diagnostic adjunct in settings in which sophisticated neuropsychological testing is not readily available.

Hippocampal atrophy confounds template-based functional MR imaging measures of hippocampal activation in patients with mild cognitive impairment

BACKGROUND AND PURPOSE

Functional MR imaging has been used to study patterns of hippocampal activation that distinguish pathologic from normal memory loss in the elderly population. Our objective was to assess whether hippocampal atrophy confounds measurements of hippocampal activation in subjects with mild cognitive impairment (MCI).

METHODS

Twenty subjects with MCI and 20 elderly control subjects with objectively normal memory were studied at 4T during a face-name paradigm designed to activate the hippocampus. Hippocampal activation was measured using 2 separate approaches: applying a preset region of interest (ROI) in standardized template space and applying a manually drawn ROI in native subject space. Pearson correlation coefficients were calculated to compare group-dependent relationships between hippocampal volume and activation. Analysis of covariance (ANCOVA) was performed to assess group differences in hippocampal activation during encoding and retrieval. Age and hippocampal volume were included as covariates, as was a term for the interaction between hippocampal volume and group.

RESULTS

When hippocampal activation was measured by the template-based method, the correlation coefficient in the right hippocampus of subjects with MCI but not control subjects during retrieval differed significantly from zero. There was a significant (P < .05) group-by-volume interaction in the ANCOVA model. No significant correlations or interactions were demonstrated when activation was measured in native subject space with manually drawn ROIs.

CONCLUSION

Our findings suggest a potential confounding relationship between hippocampal volume and activation for subjects with MCI in template-based analyses. Template-based measures of hippocampal activation that do not adequately account for hippocampal atrophy should be used with caution in patients with MCI.