Update on establishing and managing an overnight emergency radiology division.

Emergency department (ED) radiology divisions that serve to provide overnight attending coverage have become an increasingly common feature of radiology departments. The purpose of this article is to review the common ED radiology coverage models, describe desirable traits of emergency radiologists, and discuss workflow in the ED radiology setting. ED radiologists may be trained as ED radiologists or may develop the necessary skills and adopt the subspecialty. Choosing radiologists with the correct traits such as being a "night owl" and remaining calm under pressure and implementing an acceptable work schedule such as shift length of 9-10 h and a "one week on, two weeks off" schedule contribute to sustainability of the position. Strategies to address the unique stressors and workflow challenges of overnight emergency radiology coverage are also presented. Workflow facilitators including trainees, PAs, radiology assistants, and clerks all have roles to play in managing high case volumes and in making sure that the service is well staffed. Usage of artificial intelligence software is the latest technique to streamline workflow by identifying cases which should be prioritized on a busy worklist. Implementing such strategies will maintain quality of care for patients regardless of time of day as well as sustainability and quality of life for overnight emergency radiologists.

No way out: Causes of duodenal and gastric outlet obstruction.

Upper gastrointestinal obstruction (UGIO), obstruction occurring at the level of the stomach or duodenum, represents only about 5% of bowel obstructions. As with other bowel obstructions, timely diagnosis is necessary to prevent complications including ischemia and death. Because the presenting symptoms of UGIO can be vague and nonspecific, the diagnosis may not be suspected clinically. The radiologist therefore provides immense value as the diagnosis and often the etiology of the obstruction can be ascertained through imaging. Here we present a simple classification scheme of etiologies of UGIO into congenital, malignant, infectious/inflammatory, and mechanical categories, and provide examples of the most common and some uncommon causes for each category. We highlight that several of the congenital etiologies of UGIO can present at any age, including adulthood, and therefore it is important for the radiologist to keep these diagnoses in mind when reviewing cases of UGIO. For each etiology, we provide typical imaging strategies that are used for diagnosis as well as key points regarding the diagnosis.

CT of the Neck: Image Analysis and Reporting in the Emergency Setting.

Interpreting findings seen at CT of the neck is challenging owing to the complex and nuanced anatomy of the neck, which contains multiple organ systems in a relatively small area. In the emergency department setting, CT is performed to investigate acute infectious or inflammatory symptoms and chronic processes. With few exceptions, neck CT should be performed with intravenous contrast material, which accentuates abnormally enhancing phlegmonous and neoplastic tissues and can be used to delineate any abscesses or necrotic areas. As part of the evaluation, the vascular structures and aerodigestive tract must be scrutinized, particularly for patency. Furthermore, although the patient may present because of symptoms that suggest non-life-threatening conditions involving structures such as the teeth or salivary glands, there may be serious implications for other areas, such as the orbits, brain, and spinal cord, that also may be revealed at the examination. With a focus on the emergency setting, the authors propose using an approach to interpreting neck CT findings whereby 12 areas are systematically evaluated and reported on: the cutaneous and subcutaneous soft tissues, aerodigestive tract and adjacent soft tissues, teeth and periodontal tissues, thyroid gland, salivary glands, lymph nodes, vascular structures, bony airspaces, cervical spine, orbits and imaged brain, lung apices, and superior mediastinum. The use of a systematic approach to interpreting neck CT findings is essential for identifying all salient findings, recognizing and synthesizing the implications of these findings to formulate the correct diagnosis, and reporting the findings and impressions in a complete, clear, and logical manner.Online supplemental material is available for this article.©RSNA, 2019.

Implantable Electronic Stimulation Devices from Head to Sacrum: Imaging Features and Functions.

Electronic stimulation devices are implanted in various locations in the body to decrease pain, modulate nerve function, or stimulate various end organs. The authors describe these devices using a craniocaudal approach, first describing deep brain stimulation (DBS) devices and ending with sacral nerve stimulation (SNS) devices. The radiology-relevant background information for each device and its imaging appearance are also described. These devices have a common design theme and include the following components: (a) a pulse generator that houses the battery and control electronics, (b) an insulated lead or wire that conveys signals to the last component, which is (c) an electrode that contacts the end organ and senses and/or acts on the end organ. DBS electrodes are inserted into various deep gray nuclei, most commonly to treat the symptoms of movement disorders. Occipital, trigeminal, and spinal nerve stimulation devices are used as second-line therapy to control craniofacial or back pain. For cardiac devices, the authors describe two newer devices, the subcutaneous implantable cardioverter defibrillator and the leadless pacemaker, both of which avoid complications related to having leads threaded through the venous system. Diaphragmatic stimulation devices stimulate the phrenic nerve to restore diaphragmatic movement. Gastric electrical stimulation devices act on various parts of the stomach for the treatment of gastroparesis or obesity. Finally, SNS devices are used to modulate urinary and defecatory functions. Common complications diagnosed at imaging include infection, hematoma, lead migration, and lead breakage. Understanding the components, normal function, and normal imaging appearance of each device allows the radiologist to identify complications. ©RSNA, 2019.

Intraperitoneal Urinary Bladder Perforation with Pneumoperitoneum in Association with Indwelling Foley Catheter Diagnosed in Emergency Department.

BACKGROUND: Indwelling Foley catheter is a rare cause of urinary bladder perforation, a serious injury with high mortality that demands accurate and prompt diagnosis. While the gold standard for diagnosis of bladder injury is computed tomography (CT) cystography, few bladder ruptures associated with Foley catheter have been reported to be diagnosed in the emergency department (ED). CASE REPORT: An 83-year-old man with indwelling Foley catheter presented to the ED for hematuria and altered mental status. He was diagnosed to have intraperitoneal rupture of the urinary bladder in the ED using abdominal and pelvic CT without contrast, which demonstrated bladder wall discontinuity, intraperitoneal free fluid, and pneumoperitoneum. The patient was treated successfully with medical management and bladder drainage. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: To our knowledge, this is the first report of intraperitoneal urinary bladder perforation associated with Foley catheter diagnosed in the ED by CT without contrast. Pneumoperitoneum found in this case was a clue to the diagnosis and is a benign finding that does not necessitate urgent surgical intervention. The early and accurate diagnosis in this case allowed for effective management with good clinical outcome. The use of indwelling Foley catheter has a high prevalence, especially in long-term care facility residents, who are frequent visitors in the ED. Therefore, emergency physicians and radiologists should be familiar with the presentation and imaging findings of this potential injury associated with Foley catheters.

Acetabular fractures: what radiologists should know and how 3D CT can aid classification.

Correct recognition, description, and classification of acetabular fractures is essential for efficient patient triage and treatment. Acetabular fractures may result from high-energy trauma or low-energy trauma in the elderly. The most widely used acetabular fracture classification system among radiologists and orthopedic surgeons is the system of Judet and Letournel, which includes five elementary (or elemental) and five associated fractures. The elementary fractures are anterior wall, posterior wall, anterior column, posterior column, and transverse. The associated fractures are all combinations or partial combinations of the elementary fractures and include transverse with posterior wall, T-shaped, associated both column, anterior column or wall with posterior hemitransverse, and posterior column with posterior wall. The most unique fracture is the associated both column fracture, which completely dissociates the acetabular articular surface from the sciatic buttress. Accurate categorization of acetabular fractures is challenging because of the complex three-dimensional (3D) anatomy of the pelvis, the rarity of certain acetabular fracture variants, and confusing nomenclature. Comparing a 3D image of the fractured acetabulum with a standard diagram containing the 10 Judet and Letournel categories of acetabular fracture and using a flowchart algorithm are effective ways of arriving at the correct fracture classification. Online supplemental material is available for this article.

Beyond ultrasound: CT and MRI of ectopic pregnancy.

OBJECTIVE: Although ultrasound is the primary modality used in the diagnosis of ectopic pregnancy, various forms of this condition and their complications may occasionally be further evaluated with MRI or may be incidentally detected on CT or MRI when an alternative diagnosis is suspected. CONCLUSION: Various types of ectopic pregnancy have characteristic imaging features. Radiologists should be familiar with these features and should always consider the possibility of ectopic pregnancy in the setting of hemoperitoneum or a pelvic mass in a woman of child-bearing age. Familiarity with the typical CT and MRI appearances of various forms of ectopic pregnancy facilitates prompt and accurate diagnosis and treatment.

Renal stones on portal venous phase contrast-enhanced CT: does intravenous contrast interfere with detection?

PURPOSE: To determine the sensitivity of portal venous phase contrast-enhanced CT for the detection of renal stones. METHODS: This retrospective study included 97 CT examinations of the abdomen without and with intravenous contrast, including 85 (87.6%) examinations with at least one renal stone on the "gold standard" noncontrast images, as scored by a single radiologist. Three other radiologists each independently reviewed only the contrast-enhanced images from all 97 examinations and recorded all renal stones. Reviewer sensitivity for stones was categorized by stone diameter. Reviewer sensitivity and specificity for stone disease were also calculated on a per-kidney basis. RESULTS: The 97 cases included a total of 238 stones ≥1 mm, with a mean (±SD) of 1.2 ± 1.9 stones per kidney and a stone diameter of 3.5 ± 3.0 mm. Pooling data for the three reviewers, sensitivity for all stones was 81%; sensitivity for stones ≥2, ≥3, ≥4, and ≥5 mm was 88%, 95%, 99%, and 98%, respectively. Sensitivity for stone disease on a per-kidney basis was 94% when considering all stones; when considering only stones ≥2, ≥3, and ≥4 mm, sensitivity was 96%, 99%, and 100%, respectively. Specificity for stone disease on a per-kidney basis was 98% overall, 99% when considering only stones ≥2 mm, and 100% when considering only stones ≥3 mm. CONCLUSION: Contrast-enhanced CT is highly sensitive for the detection of renal stones ≥3 mm in diameter and less sensitive for smaller stones. In cases where the clinical diagnosis is uncertain and performance of a CT examination is being contemplated, intravenous contrast utilization would allow assessment for stone disease while also optimizing evaluation for other conditions.

Appropriateness of imaging studies ordered by emergency medicine residents: results of an online survey.

OBJECTIVE: The purpose of this study is to determine the proficiency of emergency medicine residents in selecting appropriate radiologic examinations for specific clinical scenarios and to ascertain whether their training improves competency in this area over the course of their residency. MATERIALS AND METHODS: An online multiple-choice questionnaire was created. It included 10 clinical scenarios excerpted from the American College of Radiology Appropriateness Criteria guidelines and instructed residents to select the most appropriate initial imaging study. A link and invitation to the survey were e-mailed to the residency program directors and coordinators of all American Council for Graduate Medical Education-accredited emergency medicine residency training programs with the request that they be forwarded to their current residents. Responses were graded, with correct answers derived from the American College of Radiology guidelines. Results were stratified by year of emergency medicine training, and an analysis of variance was performed. RESULTS: A total of 583 residents from at least 77 different emergency medicine residency training programs completed the survey. Overall, the average number of questions answered correctly was 7.1 of 10 (SD, 1.2). First-through fourth-year residents averaged 6.9 (SD, 1.3), 7.1 (SD, 1.2), 7.1 (SD, 1.1), and 7.5 (SD, 1.1) correct answers, respectively. Analysis of variance found no significant difference between the scores of the four classes (p = 0.09). CONCLUSION: Emergency medicine residents do not show significant improvement over the course of their residency in their ability to choose appropriate imaging studies. This finding suggests that there is a role for more-rigorous focused instruction to better familiarize residents with appropriateness guidelines for diagnostic imaging selection.

MR imaging of renal collecting system with gadoxetate disodium: feasibility for MR urography.

PURPOSE: To determine the feasibility of using gadoxetate disodium for MR urography. MATERIALS AND METHODS: We retrospectively reviewed 50 consecutive gadoxetate disodium-enhanced abdominal MRI examinations meeting inclusion criteria. For each examination, 30 min postcontrast hepatobiliary phase sequences were reviewed to assess bilateral collecting system segments, including upper pole, interpolar, and lower pole calyces; renal pelvis; and proximal one-third of ureter. Each segment was assessed for degree of opacification (none, <50%, ≥50%, complete) and susceptibility artifact (none, partial thin rim, thick/complete rim, total obscuration). Opacification and susceptibility scores were also calculated for each examination. RESULTS: The 50 reviewed examinations were performed on 46 patients (26 women, 20 men; mean age, 57 years) and included a total of 1000 segments. Of these, 808 (80.8%) were opacified completely, 103 (10.3%) were opacified ≥50%, 39 (3.9%) were opacified <50%, and 50 (5.0%) were not opacified. Of 1000 segments, no susceptibility artifact was present in 822 (82.2%), while a partial thin rim was present in 113 (11.3%), a thick/complete rim in 64 (6.4%) and total obscuration in 1 (0.1%). CONCLUSION: Gadoxetate disodium contrast produced a high degree of opacification of the proximal urinary collecting system with low incidence of susceptibility artifact; therefore, it is a feasible contrast agent for MR urography.

Gallbladder torsion resulting in gangrenous cholecystitis within a parastomal hernia: findings on unenhanced CT.

Gallbladder torsion is a rare cause of acute gangrenous cholecystitis; its occurrence within an abdominal hernia has not been previously reported. We present such a case occurring within a parastomal hernia and imaged with unenhanced CT.

Teeth: what radiologists should know.

Disease of the teeth and their support structures is common and frequently seen at imaging of the head and neck. Recognition of dental disease by the interpreting radiologist has the potential to alter the course of patient care, such as when periapical disease is identified as the cause of sinusitis or pericoronitis is identified as the cause of deep neck infection. Furthermore, incidental recognition of carious lesions in both children and adults who are undergoing CT for other reasons may alert the patient and care team of the need for a dental consultation. In fact, most of the images of dental and periodontal conditions that are used in this article were obtained from CT studies that were performed to investigate other problems. Familiarity with the imaging appearance of common dental conditions, such as hyperdontia and hypodontia, tooth trauma, periodontal disease, caries, periapical disease, odontogenic sinusitis, and deep neck infections, allows the radiologist to render a timely, confident, and specific diagnosis of dental abnormalities, even when such findings are unexpected.

Imaging of the paranasal sinuses.

Evaluation of the paranasal sinuses is often performed in a purely clinical fashion, without the need for imaging. However, in certain instances imaging may be deemed valuable or even necessary in helping to solve a diagnostic dilemma, confirm a suspected diagnosis, evaluate the extent of a known condition, or assess for an underlying cause of the condition. Computed tomography (CT) and magnetic resonance imaging (MRI) can be useful in confirming a suspected diagnosis or providing additional information regarding causes or complications. CT and MRI play complementary roles in evaluating the rare tumors that may involve the paranasal sinuses.

Is functional MR imaging assessment of hemispheric language dominance as good as the Wada test?: a meta-analysis.

PURPOSE: To perform a systematic review and meta-analysis to quantitatively assess functional magnetic resonance (MR) imaging lateralization of language function in comparison with the Wada test. MATERIALS AND METHODS: This study was determined to be exempt from review by the institutional review board. A systematic review and meta-analysis were performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A structured Medline search was conducted to identify all studies that compared functional MR imaging with the Wada test for determining hemispheric language dominance prior to brain surgery. Studies meeting predetermined inclusion criteria were selected independently by two radiologists who also assessed their quality using the Quality Assessment of Diagnostic Accuracy Studies tool. Language dominance was classified as typical (left hemispheric language dominance) or atypical (right hemispheric language dominance or bilateral language representation) for each patient. A meta-analysis was then performed by using a bivariate random-effects model to derive estimates of sensitivity and specificity, with Wada as the standard of reference. Subgroup analyses were also performed to compare the different functional MR imaging techniques utilized by the studies. RESULTS: Twenty-three studies, comprising 442 patients, met inclusion criteria. The sensitivity and specificity of functional MR imaging for atypical language dominance (compared with the Wada test) were 83.5% (95% confidence interval: 80.2%, 86.7%) and 88.1% (95% confidence interval: 87.0%, 89.2%), respectively. CONCLUSION: Functional MR imaging provides an excellent, noninvasive alternative for language lateralization and should be considered for the initial preoperative assessment of hemispheric language dominance. Further research may help determine which functional MR methods are most accurate for specific patient populations.