MR Angiography Series: Neurovascular MR Angiography.

Neurovascular MR angiography (MRA) is an evolving imaging technique and is crucial for the workup of numerous neurologic disorders. While CT angiography (CTA) provides a more rapid imaging assessment, in select patients it can impart a small risk of contrast material-induced nephrotoxicity or radiation-associated cancers. In addition, MRA offers some advantages over CTA for neurovascular evaluation, including higher temporal resolution and the capability for vessel wall imaging. This module is the third in a series created on behalf of the Society for Magnetic Resonance Angiography (SMRA), a group of researchers and clinicians who are passionate about the benefits of MRA but understand its challenges. The full digital presentation is available online. Work of the U.S. Government published under an exclusive license with the RSNA.

MRI for Pediatric Appendicitis in an Adult-Focused General Hospital: A Clinical Effectiveness Study-Challenges and Lessons Learned.

OBJECTIVE: The objective of our study was to determine the feasibility and accuracy of MRI for pediatric appendicitis in an adult-predominant general hospital setting where non-pediatric-trained radiologists routinely interpret the studies. MATERIALS AND METHODS: MRI was performed in pediatric patients with equivocal ultrasound (US) findings and persistent clinical concern for appendicitis. Neither IV contrast material nor a sedative was administered. Our MRI protocol evolved early during the study period, quickly settling on three sequences (total scanning time, 11 minutes). The clinical reference standard for statistical analysis was appendicitis diagnosed on operative or pathology report; 95% Clopper-Pearson CIs were calculated. RESULTS: Between 2012 and 2016, 528 pediatric patients (mean age, 9.9 years; age range, 1-17 years) underwent MRI after US evaluation yielded equivocal findings: 10.4% (55/528) of patients were found to have surgically proven or pathologically proven appendicitis. Sensitivity and specificity of MRI for appendicitis were 96.4% and 98.9%, respectively. Positive and negative predictive values were 91.2% and 99.6%. A normal appendix and abnormalities not involving the appendix were identified on MRI in 21.6% (114/528) of patients. CONCLUSION: Our data show that unenhanced MRI for suspected appendicitis in pediatric patients is clinically effective when performed in a nonpediatric hospital setting with nonpediatric radiologists, emergency physicians, and surgeons.

Does exposure to bentonite dust during tunnel hyperbaric interventions increase health risks for compressed air workers? A prospective qualitative and quantitative safety assessment.

INTRODUCTION: The mining and tunneling industries are historically associated with hazardous exposures that result in significant occupational health concerns. Occupational respiratory exposures causing pneumoconiosis and silicosis are of great concern, silicosis being non-curable. This work demonstrates that compressed-air workers (CAWs) performing tunnel hyperbaric interventions (HIs) may be at risk for hazards related to bentonite exposure, increasing the likelihood of developing harmful illnesses including cancer. Bentonite dust inhalation may result in respiratory levels of silica exceeding acceptable industrial hygiene standards. METHODS: A qualitative observational exposure assessment was conducted on CAWs while they were performing their HI duties. This was followed by quantitative data collection using personal and area air sample techniques. The results were analyzed and interpreted using standard industrial hygiene principles and guidelines from NIOSH and OSHA. RESULTS: Our work suggests bentonite dust exposure may be an emerging particulate matter concern among CAWs in the tunneling industry. Aerosolized bentonite particles may have potential deleterious effects that include pneumoconiosis and silicosis. Silicosis can result in the development of pulmonary carcinoma. CONCLUSIONS: The modern tunneling industry and required hyperbaric interventional tasks represent a potential public health and occupational concern for CAWs. This paper introduces the modern tunneling industry and the duties of CAWs, the hazardous environment in which they perform their duties, and describes the risks and potential harmful health effects associated with these hazardous exposures.

Review of Commonly Used Serum Tumor Markers and Their Relevance for Image Interpretation.

Serum tumor markers are firmly entrenched as one of the primary tools in an oncologist's armamentarium. They can be implemented in a broad range of applications from diagnostic assistance, assessing prognosis, or guiding therapeutic decisions. However, tumor markers also have limitations, which significantly impact how they should be used. Radiologists should be familiar with the following most prevalent tumor markers, which will all be discussed here: prostate-specific antigen (prostate), carcinoembryonic antigen (colon), α-fetoprotein (hepatocellular and testicular), carbohydrate antigen 19.9 (pancreas), cancer antigen 125 (ovarian), human chorionic gonadotropin/lactic dehydrogenase (testicular), and chromogranin A (neuroendocrine). This knowledge should avoid needless intervention, enhance image interpretation, and ultimately provide optimal patient care.

Carotid Plaque-RADS: A Novel Stroke Risk Classification System.

BACKGROUND: Carotid artery atherosclerosis is highly prevalent in the general population and is a well-established risk factor for acute ischemic stroke. Although the morphological characteristics of vulnerable plaques are well recognized, there is a lack of consensus in reporting and interpreting carotid plaque features. OBJECTIVES: The aim of this paper is to establish a consistent and comprehensive approach for imaging and reporting carotid plaque by introducing the Plaque-RADS (Reporting and Data System) score. METHODS: A panel of experts recognized the necessity to develop a classification system for carotid plaque and its defining characteristics. Using a multimodality analysis approach, the Plaque-RADS categories were established through consensus, drawing on existing published reports. RESULTS: The authors present a universal classification that is applicable to both researchers and clinicians. The Plaque-RADS score offers a morphological assessment in addition to the prevailing quantitative parameter of "stenosis." The Plaque-RADS score spans from grade 1 (indicating complete absence of plaque) to grade 4 (representing complicated plaque). Accompanying visual examples are included to facilitate a clear understanding of the Plaque-RADS categories. CONCLUSIONS: Plaque-RADS is a standardized and reliable system of reporting carotid plaque composition and morphology via different imaging modalities, such as ultrasound, computed tomography, and magnetic resonance imaging. This scoring system has the potential to help in the precise identification of patients who may benefit from exclusive medical intervention and those who require alternative treatments, thereby enhancing patient care. A standardized lexicon and structured reporting promise to enhance communication between radiologists, referring clinicians, and scientists.

CT radiation dose: current controversies and dose reduction strategies.

OBJECTIVE: The purpose of this article is to use clinical scenarios to explore aspects of ionizing radiation imparted to patients undergoing CT examinations. Examination appropriateness, effective doses, cancer risks, and pertinent dose reduction strategies are reviewed. CONCLUSION: CT accounts for the majority of radiation exposure related to medical imaging. Medical professionals should have a working knowledge of the benefits and risks of medical radiation and an understanding of strategies for reducing CT radiation dose.

Time for change? Radiologists highly concordant assessing change in stenoses on follow-up cervical spine MRI.

OBJECTIVE: There is considerable variability among radiologists when grading spinal canal and foraminal stenosis on MRI. However, to date, studies have not evaluated radiologists' agreement when assessing interval change in cervical spine stenoses. The purpose of this study was to evaluate radiologists' concordance for change in cervical spine stenoses on follow-up MRIs, a major indication for these exams. METHODS: Initial and follow-up cervical MRIs were retrospectively reviewed by three blinded radiologists. Spinal canal and foramina from C1 through T1 were rated for interval change and concordance between the blinded raters was calculated. The original MRI reports were also reviewed for specific language assessing interval change on the follow-up exams. RESULTS: 40 cervical MRI exams and 40 corresponding MRI follow-ups were assessed. Agreement for interval change in spinal canal and foraminal stenosis was near perfect amongst all readers (kappa values of 0.78-0.94). 97% of the original MRI reports used the standard severity scale. 68% of follow-up MRI reports specifically assessed for change. DISCUSSION: Blinded radiologists had high agreement when assessing for change in spinal canal and foraminal stenosis on follow-up cervical spine MRIs. Because of inter-rater variability in stenosis grading, reports that do not emphasize change assessment, may imply change that is not truly present. For clarity and consistency in reporting of cervical spine stenoses, change assessment should be emphasized and added to structured reporting templates.

Hazards and Management of Wire Bristle ingestions: A Systematic Review.

OBJECTIVE: Inadvertently ingested grill brush bristles can lodge in various locations and lead to a variety of injuries. They can also be difficult to identify and remove. Our primary objective was to perform a systematic review of cases reported in the literature, with analysis of trends in clinical presentation and success of diagnostic modalities and treatment approaches. DATA SOURCES: Cases of reported grill brush bristle ingestion reported in PubMed, PubMed Central, and Google Scholar databases through April 30, 2021. REVIEW METHODS: Databases were searched for the following terms: ("ingestion" OR "injury" OR "barbeque" OR "BBQ" OR "grill" OR "foreign body" OR "brush" AND "wire" OR "bristle"). Data were collected on patient demographics, clinical presentation, and treatment course. Statistical analysis was performed on characteristics with low risk of confounding. RESULTS: An overall 57 studies involving 91 patients were included. Grill brush bristles presented most commonly in the upper aerodigestive tract (48/91), followed by the abdomen (26/91) and deep neck (17/91). Computed tomography was the most accurate imaging modality for initial diagnosis, identifying 92.8% of bristles. Less invasive or adjunctive techniques such as endoscopy, intraoperative imaging, or minimally invasive surgery may be useful particularly for bristles located in the head and neck given the low rate of success of transoral surgery (66.7%). CONCLUSION: Although this review of retained bristle may be biased toward complex cases, retained grill brush bristles represent an underrecognized and difficult-to-manage hazard. When cases are suspected, clinicians should obtain computed tomography imaging based on presentation and tailor management appropriately.

Shifting Spine Interventional Pain Injections From the Hospital to a Clinic Setting: Increased Efficiency and Decreased Health System Costs.

OBJECTIVE: Spine interventional pain injections have dramatically increased in volume in the past three decades. High referral volumes at our institution necessitated using both a hospital-based interventional suite and a clinic-based suite scheduled on a first-come, first-served basis. We sought to determine whether the clinic-based suite provided benefits in efficiency and health system cost in comparison with the hospital suite without compromising quality of care. METHODS: To investigate differences between outpatient procedures performed in hospital-based procedure rooms (HBPRs) and clinic-based procedure rooms (CBPRs), we reviewed all consecutive outpatient spine interventional pain procedures performed by the interventional neuroradiology service over a 12-month period. We analyzed procedure complexity, fluoroscopic times, procedural times, patient wait times, and health system costs for each case, as well as any complications. RESULTS: Our analysis demonstrated similar procedural complexity between sites with decreased average fluoroscopic time (112 seconds versus 163 seconds, P = .002), procedural time (17 min versus 28 min, P < .001), and wait time (20 min versus 38 min, P < .001) in the CBPR versus the HBPR. In cases without trainee involvement, procedural and wait times were decreased (P < .001, P = .008) with no difference in fluoroscopy time (P = .18). There were no complications at either site. The analysis of cost to the health system demonstrated that procedures in the HBPR cost >14 times the amount to perform than in the CBPR. DISCUSSION: Performing spine interventional pain procedures in a CBPR adds value by decreasing procedural, fluoroscopic, wait times, and health system cost compared with an HBPR without compromising safety.

Imaging Appropriateness for Neck Pain.

Imaging of neck pain contributes to a significant proportion of health care costs and is expected to increase with current practices that heavily use radiologic studies as a diagnostic tool. Though consensus guidelines are available to assist physicians in selection of appropriate imaging examinations for neck pain, it is unclear if current ordering practices reflect their use and understanding. To investigate this, we analyzed the number and types of imaging examinations performed for neck pain at a university medical center over the past year. Current trends at our institution suggest that clinicians use consensus imaging guidelines, but there is still controversy in the cervical spine for when not to image. To promote appropriate imaging utilization, we developed an algorithm to guide imaging of neck pain, based upon clinical presentation, referral patterns for neck pain, and a review of the literature.

Reduction of nasal Staphylococcus aureus carriage in health care professionals by treatment with a nonantibiotic, alcohol-based nasal antiseptic.

BACKGROUND: Antibiotics used to reduce nasal colonization by Staphylococcus aureus in patients before admission are inappropriate for carriage reduction on a regular basis within a hospital community. Effective nonantibiotic alternatives for daily use in the nares will allow reduction of this bacterial source to be addressed. METHODS: Our study tested the effectiveness of a nonantibiotic, alcohol-based antiseptic in reducing nasal bacterial carriage in health care professionals (HCPs) at an urban hospital center. HCPs testing positive for vestibular S aureus colonization were treated 3 times during the day with topical antiseptic or control preparations. Nasal S aureus and total bacterial colonization levels were determined before and at the end of a 10-hour workday. RESULTS: Seventy-eight of 387 HCPs screened (20.2%) tested positive for S aureus infection. Of 39 subjects who tested positive for S aureus infection who completed the study, 20 received antiseptic and 19 received placebo treatment. Antiseptic treatment reduced S aureus colony forming units from baseline by 99% (median) and 82% (mean) (P < .001). Total bacterial colony forming units were reduced by 91% (median) and 71% (mean) (P < .001). CONCLUSIONS: Nasal application of a nonantibiotic, alcohol-based antiseptic was effective in reducing S aureus and total bacterial carriage, suggesting the usefulness of this approach as a safe, effective, and convenient alternative to antibiotic treatment.