National trends in use of computed tomography in the emergency department

Efficient management of pulmonary embolism diagnosis using a two-step interconnected machine learning model based on electronic health records data

Pulmonary Embolism (PE) is a life-threatening clinical disease with no specific clinical symptoms and Computed Tomography Angiography (CTA) is used for diagnosis. Clinical decision support scoring systems like Wells and rGeneva based on PE risk factors have been developed to estimate the pre-test probability but are underused, leading to continuous overuse of CTA imaging. This diagnostic study aimed to propose a novel approach for efficient management of PE diagnosis using a two-step interconnected machine learning framework directly by analyzing patients' Electronic Health Records data. First, we performed feature importance analysis according to the result of LightGBM superiority for PE prediction, then four state-of-the-art machine learning methods were applied for PE prediction based on the feature importance results, enabling swift and accurate pre-test diagnosis. Throughout the study patients' data from different departments were collected from Sina educational hospital, affiliated with the Tehran University of medical sciences in Iran. Generally, the Ridge classification method obtained the best performance with an F1 score of 0.96. Extensive experimental findings showed the effectiveness and simplicity of this diagnostic process of PE in comparison with the existing scoring systems. The main strength of this approach centered on PE disease management procedures, which would reduce avoidable invasive CTA imaging and be applied as a primary prognosis of PE, hence assisting the healthcare system, clinicians, and patients by reducing costs and promoting treatment quality and patient satisfaction.

Longitudinal changes in the US emergency department use of advanced neuroimaging in the mechanical thrombectomy era

PURPOSE

To describe ED neuroimaging trends across the time-period spanning the early adoption of endovascular therapy for acute stroke (2013-2018).

MATERIALS AND METHODS

We performed a retrospective, cross-sectional study of ED visits using the 2013-2018 National Emergency Department Sample, a 20% sample of ED encounters in the United States. Neuroimaging use was determined by Common Procedural Terminology (CPT) code for non-contrast head CT (NCCT), CT angiography head (CTA), CT perfusion (CTP), and MRI brain (MRI) in non-admitted ED patients. Data was analyzed according to sampling weights and imaging rates were calculated per 100,000 ED visits. Multivariate logistic regression analysis was performed to identify hospital-level factors associated with imaging utilization.

RESULTS

Study population comprised 571,935,906 weighted adult ED encounters. Image utilization increased between 2013 and 2018 for all modalities studied, although more pronounced in CTA (80.24/100,000 ED visits to 448.26/100,000 ED visits (p < 0.001)) and CTP (1.75/100,000 ED visits to 28.04/100,000 ED visits p < 0.001)). Regression analysis revealed that teaching hospitals were associated with higher odds of high CTA utilization (OR 1.88 for 2018, p < 0.05), while low-volume EDs and public hospitals showed the reverse (OR 0.39 in 2018, p < 0.05).

CONCLUSIONS

We identified substantial increases in overall neuroimaging use in a national sample of non-admitted emergency department encounters between 2013 and 2018 with variability in utilization according to both patient and hospital properties. Further investigation into the appropriateness of this imaging is required to ensure that access to acute stroke treatment is balanced against the timing and cost of over-imaging.

Emergency physician gender and head computed tomography orders for older adults who have fallen

OBJECTIVE

Physicians vary in their computed tomography (CT) scan usage. It remains unclear how physician gender relates to clinical practice or patient outcomes. The aim of this study was to assess the association between physician gender and decision to order head CT scans for older emergency patients who had fallen.

METHODS

This was a secondary analysis of a prospective observational cohort study conducted in 11 hospital emergency departments (EDs) in Canada and the United States. The primary study enrolled patients who were 65 years and older who presented to the ED after a fall. The analysis evaluated treating physician gender adjusted for multiple clinical variables. Primary analysis used a hierarchical logistic regression model to evaluate the association between treating physician gender and the patient receiving a head CT scan. Secondary analysis reported the adjusted odds ratio (OR) for diagnosing intracranial bleeding by physician gender.

RESULTS

There were 3663 patients and 256 physicians included in the primary analysis. In the adjusted analysis, women physicians were no more likely to order a head CT than men (OR 1.26, 95% confidence interval 0.98-1.61). In the secondary analysis of 2294 patients who received a head CT, physician gender was not associated with finding a clinically important intracranial bleed.

CONCLUSIONS

There was no significant association between physician gender and ordering head CT scans for older emergency patients who had fallen. For patients where CT scans were ordered, there was no significant relationship between physician gender and the diagnosis of clinically important intracranial bleeding.

Trends in visits, imaging, and diagnosis for emergency department abdominal pain presentations in the United States, 2007-2019

OBJECTIVES

Abdominal pain is the most common reason for visit (RFV) to the emergency department (ED) for adults, yet no standardized diagnostic pathway exists for abdominal pain. Optimal management is age-specific; symptoms, diagnoses, and prognoses differ between young and old adults. Availability and knowledge of the effectiveness of various imaging modalities have also changed over time. We compared diagnostic imaging rates for younger versus older adults to identify practice patterns of abdominal imaging across age groups over time.

METHODS

We analyzed weighted, nationally representative data from the National Hospital Ambulatory Medical Care Survey 2007-2019 for adult ED visits with a primary RFV of abdominal pain. We included 23,364 sampled visits, representing 123 million visits.

RESULTS

From 2007 to 2019, total visits increased for ages 18-45 (p < 0.001), 46-64 (p < 0.001), and 65+ (p = 0.032). The percentage of visits with primary RFV of abdominal pain increased from 9.4% to 11.6% for ages 18-45, 7.8%-9.0% for ages 46-64, and 6.0%-6.5% for 65+. Computed tomography (CT) scan rates increased over time from 26.2% of all patients receiving a CT scan to 42.6%. Relative percentage change in abdominal CT scans was greatest for older adults, with a 30.3% increase, compared to 24.0% for middle-aged adults and 15.0% for young adults. Test positivity, defined as receiving an emergency general surgical diagnosis after CT or ultrasound, increased from 17.2% in 2007 to 22.9% in 2019 (p < 0.01). Of the older adults with abdominal pain in 2019, 13% received an X-ray only, which is neither sensitive nor specific for acute pathology in older adults.

CONCLUSIONS

Despite more abdominal pain ED visits and increased imaging rates per visit, test positivity continues to rise. Our findings do not support claims that CT and ultrasound are being used less appropriately over time, but demonstrate widespread use of X-rays, which are potentially ineffective for abdominal pain.

Investigating the causes and pattern of peritoneal involvement in CT scan and comparison with ultrasound findings in peritoneal conditions: A two-center, cross-sectional study

Background and Aims

Ultrasound and computed tomography (CT) scans can be used as methods to help make a more accurate diagnosis in diseases involving the omentum and peritoneum. The present study was conducted to determine etiology and CT scan pattern of peritoneal involvement and compare it with ultrasound findings.

Methods

Patients referred to Ghaem and Imam Reza hospitals who had undergone CT scans and had involvement of peritoneum in abdominal CT scans were included in the study. The findings identified in the CT scan were recorded. According to the underlying cause determined by laparotomy or laparoscopy sample, each disease's most common pattern of involvement and types of patterns were examined. An ultrasound was conducted for every patient and the obtained information was analyzed.

Results

A total of 101 patients were included in the study, of which 61 patients (59.8%) were female and the rest were male. The most common involvement patterns in CT scans included nodular (37.6%), mixed (21.8%), and omental cake (17.8%), respectively. In 80 patients (79.2%), CT scan findings were consistent with ultrasound, but in 21 patients (20.8%), CT scan findings were not visible in ultrasound. The most common diagnoses of the patients were colorectal adenocarcinoma and gastric adenocarcinoma (20 cases, 19.8% each), followed by ovarian and uterine adenocarcinoma (19 cases, 18.8%).

Conclusion

The most common patterns of involvement of peritoneum in CT scans include nodular pattern, mix, and omental cake. The most common diseases that lead to the involvement of peritoneum are gastrointestinal cancers, uterine and ovarian cancers, and peritonitis.

The Effect of Contrast Rationing on the Development of Acute Kidney Injury During the Global Contrast Shortage

BACKGROUND

In April of 2022, the COVID-19 pandemic resulted in a global shortage of intravenous contrast media (ICM), which led our health care system to implement rationing measures.

STUDY OBJECTIVES

We set out to determine if the reduction in ICM use was associated with a change in the incidence of acute kidney injury (AKI).

METHODS

We conducted a multicenter retrospective cohort analysis to compare the incidence of AKI in patients who presented before and after ICM rationing. Adult patients who had a CT of the abdomen performed who had at least 2 creatinine measurements, at least 24 h apart, were included. The maximum increase in creatinine was determined by subtracting the maximal creatinine obtained within 7 days with the initial creatinine. The primary outcome was the development of AKI.

RESULTS

A total of 2168 patients met inclusion criteria (1082 before; 1086 after). There was no significant difference in age, gender, comorbid conditions, disposition, or initial estimated glomerular filtration rate between groups. In the prerationing group, 87.7% of patients received ICM compared to 42.7% after. There was no significant difference in the development of AKI between groups (11.1% vs. 11.0%), including when stratified by baseline renal function and adjusted for age, sex, race, comorbid conditions, and emergency severity index.

CONCLUSIONS

The dramatic reduction in ICM use that resulted from the global shortage was not associated with a change in the incidence of AKI. This reinforces the results of previous studies which have failed to find evidence of a relationship between ICM administration and AKI.

Poor Compliance to Clinical Guidelines in the Diagnosis of Acute Appendicitis: Insights from a National Survey

Background: Many scoring systems, algorithms, and guidelines have been developed to aid in the evaluation and diagnosis of acute appendicitis (AA). Many of these algorithms advocate against the routine use of radiological investigations when there is a high clinical suspicion of AA. However, there has been a significant rise in the use of imaging techniques for diagnosing AA in the past two decades. This is a national study aimed at assessing the adherence of residents assigned to the emergency department to the clinical guidelines for diagnosing AA. Methods: We introduced a case study of a male patient with highly suspicious clinical findings of AA to all surgical and emergency medicine residents assigned to the emergency department with the autonomy to make critical decisions to determine the preferred way of diagnosing AA. Results: A total of 62.4% of all relevant residents participated in this survey; 69.6% reported that the Alvarado score was eight or higher, and 82.1% estimated that the next step recommended by most clinical guidelines was appendectomy without further abdominal imaging tests. However, 83.4% chose to perform an imaging test to establish the diagnosis of AA. Conclusions: Our study revealed a notable non-adherence to clinical guidelines in diagnosing AA. Given the significance of these guidelines, we assert that adopting medical recommendations should not solely depend on individual education but should also be incorporated as a departmental policy.

Anatomically aware dual-hop learning for pulmonary embolism detection in CT pulmonary angiograms

Pulmonary Embolisms (PE) represent a leading cause of cardiovascular death. While medical imaging, through computed tomographic pulmonary angiography (CTPA), represents the gold standard for PE diagnosis, it is still susceptible to misdiagnosis or significant diagnosis delays, which may be fatal for critical cases. Despite the recently demonstrated power of deep learning to bring a significant boost in performance in a wide range of medical imaging tasks, there are still very few published researches on automatic pulmonary embolism detection. Herein we introduce a deep learning based approach, which efficiently combines computer vision and deep neural networks for pulmonary embolism detection in CTPA. Our method brings novel contributions along three orthogonal axes: (1) automatic detection of anatomical structures; (2) anatomical aware pretraining, and (3) a dual-hop deep neural net for PE detection. We obtain state-of-the-art results on the publicly available multicenter large-scale RSNA dataset.

Implementation of an Institution-Wide Rules-Based Automated CT Protocoling System

BACKGROUND. Examination protocoling is a noninterpretive task that increases radiologists' workload and can cause workflow inefficiencies. OBJECTIVE. The purpose of this study was to evaluate effects of an automated CT protocoling system on examination process times and protocol error rates. METHODS. This retrospective study included 317,597 CT examinations (mean age, 61.8 ± 18.1 [SD] years; male, 161,125; female, 156,447; unspecified sex, 25) from July 2020 to June 2022. A rules-based automated protocoling system was implemented institution-wide; the system evaluated all CT orders in the EHR and assigned a protocol or directed the order for manual radiologist protocoling. The study period comprised pilot (July 2020 to December 2020), implementation (January 2021 to December 2021), and postimplementation (January 2022 to June 2022) phases. Proportions of automatically protocoled examinations were summarized. Process times were recorded. Protocol error rates were assessed by counts of quality improvement (QI) reports and examination recalls and comparison with retrospectively assigned protocols in 450 randomly selected examinations. RESULTS. Frequency of automatic protocoling was 19,366/70,780 (27.4%), 68,875/163,068 (42.2%), and 54,045/83,749 (64.5%) in pilot, implementation, and postimplementation phases, respectively (p < .001). Mean (± SD) times from order entry to protocol assignment for automatically and manually protocoled examinations for emergency department examinations were 0.2 ± 18.2 and 2.1 ± 69.7 hours, respectively; mean inpatient examination times were 0.5 ± 50.0 and 3.5 ± 105.5 hours; and mean outpatient examination times were 361.7 ± 1165.5 and 1289.9 ± 2050.9 hours (all p < .001). Mean (± SD) times from order entry to examination completion for automatically and manually protocoled examinations for emergency department examinations were 2.6 ± 38.6 and 4.2 ± 73.0 hours, respectively (p < .001); for inpatient examinations were 6.3 ± 74.6 and 8.7 ± 109.3 hours (p = .001); and for outpatient examinations were 1367.2 ± 1795.8 and 1471.8 ± 2118.3 hours (p < .001). In the three phases, there were three, 19, and 25 QI reports and zero, one, and three recalls, respectively, for automatically protocoled examinations, versus nine, 19, and five QI reports and one, seven, and zero recalls for manually protocoled examinations. Retrospectively assigned protocols were concordant with 212/214 (99.1%) of automatically protocoled versus 233/236 (98.7%) of manually protocoled examinations. CONCLUSION. The automated protocoling system substantially reduced radiologists' protocoling workload and decreased times from order entry to protocol assignment and examination completion; protocol errors and recalls were infrequent. CLINICAL IMPACT. The system represents a solution for reducing radiologists' time spent performing noninterpretive tasks and improving care efficiency.

Development, validation, and simplification of a scanner-specific CT simulator

BACKGROUND

Simulated computed tomography (CT) images allow for knowledge of the underlying ground truth and for easy variation of imaging conditions, making them ideal for testing and optimization of new applications or algorithms. However, simulating all processes that affect CT images can result in simulations that are demanding in terms of processing time and computer memory. Therefore, it is of interest to determine how much the simulation can be simplified while still achieving realistic results.

PURPOSE

To develop a scanner-specific CT simulation using physics-based simulations for the position-dependent effects and shift-invariant image corruption methods for the detector effects. And to investigate the impact on image realism of introducing simplifications in the simulation process that lead to faster and less memory-demanding simulations.

METHODS

To make the simulator realistic and scanner-specific, the spatial resolution and noise characteristics, and the exposure-to-detector output relationship of a clinical CT system were determined. The simulator includes a finite focal spot size, raytracing of the digital phantom, gantry rotation during projection acquisition, and finite detector element size. Previously published spectral models were used to model the spectrum for the given tube voltage. The integrated energy at each element of the detector was calculated using the Beer-Lambert law. The resulting angular projections were subsequently corrupted by the detector modulation transfer function (MTF), and by addition of noise according to the noise power spectrum (NPS) and signal mean-variance relationship, which were measured for different scanner settings. The simulated sinograms were reconstructed on the clinical CT system and compared to real CT images in terms of CT numbers, noise magnitude using the standard deviation, noise frequency content using the NPS, and spatial resolution using the MTF throughout the field of view (FOV). The CT numbers were validated using a multi-energy CT phantom, the noise magnitude and frequency were validated with a water phantom, and the spatial resolution was validated with a tungsten wire. These metrics were compared at multiple scanner settings, and locations in the FOV. Once validated, the simulation was simplified by reducing the level of subsampling of the focal spot area, rotation and of detector pixel size, and the changes in MTFs were analyzed.

RESULTS

The average relative errors for spatial resolution within and across image slices, noise magnitude, and noise frequency content within and across slices were 3.4%, 3.3%, 4.9%, 3.9%, and 6.2%, respectively. The average absolute difference in CT numbers was 10.2 HU and the maximum was 22.5 HU. The simulation simplification showed that all subsampling can be avoided, except for angular, while the error in frequency at 10% MTF would be maximum 16.3%.

CONCLUSION

The simulation of a scanner-specific CT allows for the generation of realistic CT images by combining physics-based simulations for the position-dependent effects and image-corruption methods for the shift-invariant ones. Together with the available ground truth of the digital phantom, it results in a useful tool to perform quantitative analysis of reconstruction or post-processing algorithms. Some simulation simplifications allow for reduced time and computer power requirements with minimal loss of realism.

The utility of the abdominal series in the emergency setting: a retrospective review

PURPOSE

The abdominal series (AXR) remains a frequently ordered test in the emergency department (ED), despite existing literature questioning its utility. The aim of this study was to characterize the use of the AXR in the ED by quantifying how often it is ordered and the frequency of subsequent imaging. Additionally, a time estimate in ED associated with the AXR was quantified. We hypothesized that there would be a low clinical utility of the AXR, and long associated time period spent in the ED.

METHODS

A retrospective audit of AXRs performed in the ED from January to December 2019 was performed. The local picture archiving and communication system (PACS) and electronic medical record were used to collect the variables.

RESULTS

Of 701 AXRs, 438 (62.4%) were reported normal, and 263 (37.6%) were abnormal. A Chi Squared test showed that the two variables (abdominal series result and follow up imaging completion) were significantly related, with p < 0.001. However, the effect size was small (Nagelkerke R square = 0.022). The average time spent in the ED for these patients was 7.27 h, and the average time between the AXR being ordered and interpreted was 1.31 h.

CONCLUSION

The majority of AXRs were reported as normal. Our results showed that AXR had a statistically significant, but low clinically significant predictive ability on subsequent imaging ordering. This supports our hypothesis that the AXR is of low clinical utility with respect to the rate of ordering follow up imaging. The AXR also translated to a quantifiable time interval during the patient's stay in ED. Minimizing overuse of the AXR may result in a decrease in patient duration in the ED.

Medical Malpractice and Diagnostic Radiology: Challenges and Opportunities

Medicolegal challenges in radiology are broad and impact both radiologists and patients. Radiologists may be affected directly by malpractice litigation or indirectly due to defensive imaging ordering practices. Patients also could be harmed physically, emotionally, or financially by unnecessary tests or procedures. As technology advances, the incorporation of artificial intelligence into medicine will bring with it new medicolegal challenges and opportunities. This article reviews the current and emerging direct and indirect effects of medical malpractice on radiologists and summarizes evidence-based solutions.

Impact of Predictive Text Clinical Decision Support on Imaging Order Entry in the Emergency Department

PURPOSE

Imaging clinical decision support (CDS) is designed to assist providers in selecting appropriate imaging studies and is now federally required. The aim of this study was to understand the effect of CDS on decisions and workflows in the emergency department (ED).

METHODS

The authors' institution's order entry platform serves up structured indications for imaging orders. Imaging orders are scored by CDS on the basis of appropriate use criteria (AUC). CDS triggers alerts for imaging orders with low AUC scores. Because free text alone cannot be scored by CDS, an artificial intelligence predictive text (AIPT) module was implemented to guide the selection of structured indications when free-text indications are entered. A total of 17,355 imaging orders in the ED over 6 months were retrospectively analyzed.

RESULTS

CDS alerts for low AUC scores were triggered for 3% of all imaging study orders (522 of 17,355). Providers spent an average of 24 seconds interacting with alerts. In 18 of 522 imaging orders with alerts, alternative studies were ordered. After AIPT implementation, the percentage of unscored studies significantly decreased from 81% to 45% (P < .001).

CONCLUSIONS

In a quaternary academic ED, CDS alerts triggered by low AUC scores caused minimal increase in time spent on imaging order entry but had a relatively marginal impact on imaging study selection. AIPT implementation increased the number of scored studies and could potentially enhance CDS effects. CDS implementation enables the collection of novel data regarding which imaging studies receive low AUC scores. Future work could include exploring alternative models of CDS implementation to maximize its impact.

Evaluation of Abdominal Emergencies

Early primary assessment and abdominal examination can often be enough to triage the patient with abdominal pain into those with less severe underlying pathologic condition from those with more acute findings. A focused history of the patient can then allow the clinician to develop their differential diagnosis. Once the differential diagnoses are determined, diagnostic imaging and laboratory findings can help confirm the diagnosis and allow for expeditious treatment and intervention.

Evaluation of extensive inflammatory conditions of the bowel using three-dimensional CT cinematic rendering: focus on inflammatory bowel disease

Inflammatory conditions that affect long segments of bowel and/or the mesentery and mesenteric vasculature are a common cause of emergency department visits and evaluation by cross-sectional imaging. Inflammatory bowel disease, specifically Crohn disease and ulcerative colitis, can be unsuspected at presentation and may only be eventually diagnosed based on initial imaging findings. Traditional 2D axial reconstructions and multi-planar reformations can be limited in their ability to globally assess the extent of disease. 3D methods such as volume rendering (VR) are often used as adjunctive means of visualizing the pathology in such patients. Recently, a novel technique known as cinematic rendering (CR) has emerged, utilizing advanced lighting models and ray tracing to simulate photon interactions with tissues, resulting in realistic shadows and enhanced surface detail compared to VR. Generating CR images from select presets takes an experienced radiologist approximately 5 min, meaning that the technique can be incorporated into meaningful emergency department workflows. Given the apparent advantages of CR, we highlight its application in a series of cases in which patients had inflammatory conditions that affected long segments of bowel and/or involved the mesentery, particularly those patients with inflammatory bowel disease, but also including patients with mesenteric venous thrombosis and lymphedema. Those conditions included inflammatory bowel disease, mesenteric venous thrombosis, and bowel lymphedema. We present examples of those conditions in this pictorial essay and describe the potential of CR to visualize key findings. As CR exhibits possible advantages, further studies are warranted to support its broader clinical adoption and assess its efficacy in diagnosing and guiding managing of inflammatory conditions in emergency settings.

Association of Patient English Proficiency and Diagnostic Imaging Acquisition in Emergency Department Patients with Abdominal Symptoms

BACKGROUND

Patients with limited English proficiency (LEP) are at risk for communication barriers during medical care in the United States compared with English-proficient (EP) patients. It is unknown how EP affects the utilization of advanced diagnostic imaging (ADI) in the emergency department (ED).

OBJECTIVE

The aim of this study was to compare the acquisition and findings of ADI in EP and LEP patients with abdominal symptoms.

METHODS

We conducted a retrospective analysis of adult ED patients from January 2015 to January 2016. Patients were divided into EP and LEP cohorts. Logistic regression models incorporated language proficiency, interpretation method, and demographic characteristics. We determined crude and adjusted odds ratios (ORs) for the acquisition of ADI, defined as either computed tomography or ultrasound, and the proportion with actionable findings.

RESULTS

In 3324 encounters (2134 EP; 1190 LEP), LEP patients were older (46.3 years vs. 43.8 years), more likely to be female (66.7% vs. 51.5%), and preferred Spanish (91.4%). ADI was obtained in 43.5% of EP and 48.1% of LEP. Adjusting for age, sex, and interpretation method, the OR was 1.09 (95% CI 0.90-1.32). There were no significant associations between interpretation type and acquisition of ADI. The proportion with actionable findings were similar in EP and LEP cohorts (29.6% vs. 26.7%).

CONCLUSIONS

Accounting for demographic differences, ADI acquisition was similar for ED patients with and without LEP. Further research is needed to determine optimal interpretation modalities in this setting to prevent unnecessary imaging.

Study of the Natural Crystalline Lens Characteristics Using Dual-Energy Computed Tomography

There is a paucity of radiologic literature regarding age-related cataract, and little is known about any differences in the imaging appearance of the natural crystalline lens on computed tomography (CT) exams among different demographic groups. In this retrospective review of 198 eyes in 103 adults who underwent dual-energy computed tomography (DECT) exams of the head, regions of interest spanning 3−5 mm were placed over the center of the lens, and the x-ray attenuation of each lens was recorded in Hounsfield Units (HU) at 3 energy levels: 40 keV, 70 keV, and 190 keV. Generalized estimating equations (GEEs) were used to assess the association of clinical or demographic data with lens attenuation. The mean HU values were significantly lower for the older vs. younger group at 40 keV (GEE p-value = 0.022), but there was no significant difference at higher energy levels (p > 0.05). Mean HU values were significantly higher for females vs. males and non-whites vs. non-Hispanic whites at all 3 energy levels in bivariate and multivariable analyses (all p-value < 0.05). There was no significant association between lens attenuation and either diabetes or smoking status. The crystalline lens of females and non-whites had higher attenuation on DECT which may suggest higher density or increased concentration of materials like calcium and increased potential for cataract formation. Given the large scope of cataracts as a cause of visual impairment and the racial disparities that exist in its detection and treatment, further investigation into the role of opportunistic imaging to detect cataract formation is warranted.

Association of State Share of Nonphysician Practitioners With Diagnostic Imaging Ordering Among Emergency Department Visits for Medicare Beneficiaries

IMPORTANCE

The use of nonphysician practitioners (NPPs) in the emergency department (ED) continues to expand, yet little is known about associations between NPPs and ED imaging use.

OBJECTIVE

To investigate whether the state share of ED visits for which an NPP was the clinician of record is associated with imaging studies ordered, given that state NPP share is associated with state-level NPP scopes of practice.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study compared diagnostic imaging ordering patterns associated with ED visits based on 2005-2020 Medicare claims for a nationally representative 5% sample of fee-for-service beneficiaries. For all 50 states and the District of Columbia, the state NPP share of ED visits by year was used to represent state-specific practice patterns for NPPs and physicians and how those patterns have evolved over time. The analysis controlled for patient demographic characteristics, Charlson Comorbidity Index scores, ED visit severity, year, and principal diagnosis.

EXPOSURES

The share of ED visits in each state in each year (state share) for which an NPP was the evaluation and management clinician.

MAIN OUTCOMES AND MEASURES

The main outcomes were the number and modality of imaging studies associated with ED visits. Analyses were by logistic regression and generalized linear model with γ-distribution and log-link function.

RESULTS

Among 16 922 274 ED visits, 60.0% involved women, and patients' mean (SD) age was 70.3 (16.1) years. The share of all ED visits with an NPP as the clinician increased from 6.1% in 2005 to 16.6% in 2020. Compared with no NPPs, the presence of NPPs in the ED was associated with 5.3% (95% CI, 5.1%-5.5%) more imaging studies per ED visit, including a 3.4% (95% CI, 3.2%-3.5%) greater likelihood of any imaging order per ED visit and 2.2% (95% CI, 2.0%-2.3%) more imaging studies ordered per visit involving imaging.

CONCLUSIONS AND RELEVANCE

In this study, use of NPPs in the ED was associated with higher imaging use compared with the use of only physicians in the ED. Although expanded use of NPPs in the ED may improve patient access, the costs and radiation exposure associated with more imaging warrants additional study.

Prevalence and consequences of non-adherence to an evidence-based approach for incidental pulmonary nodules

Importance

Distinguishing benign from malignant pulmonary nodules is challenging. Evidence-based guidelines exist, but their impact on patient-centered outcomes is unknown.

Objective

To understand if the evaluation of incidental pulmonary nodules that follows an evidence-based management strategy is associated with fewer invasive procedures for benign lesions and/or fewer delays in cancer diagnosis.

Design

Retrospective cohort study.

Setting

Large academic medical center.

Participants

Adults (≥18 years age) with an incidental pulmonary nodule discovered between January 2012 and December 2014. Patients with calcified nodules, prior nodules, prior diagnosis of cancer, high suspicion for pulmonary metastasis, or limited life expectancy were excluded.

Exposure

Nodule management strategy (pre-specified based on evidence-based practices).

Outcome

Composite of any invasive procedure for a benign nodule or delay in diagnosis in patients with cancer (>3 month delay once probability of cancer was >15%).

Results

Of 314 patients that met inclusion criteria, median age was 61, 46.5% were men, and 66.5% had current or former tobacco use. The mean nodule size was 10.3 mm, mean probability of cancer was 11.8%, and 14.3% of nodules were malignant. Evaluation followed an evidence-based strategy in 245 patients (78.0%), and deviated in 69 patients (22%). The composite outcome occurred in 26 (8.3%) patients. Among patients whose nodule evaluation was concordant with an evidence-based evaluation, 6.1% (15/245) experienced the composite outcome versus 15.9% (11/69) of patients with an evaluation that deviated from evidence-based recommendations (P<0.01).

Conclusions and relevance

At a large academic medical center, more than 1 in 5 patients with an incidental pulmonary nodule underwent evaluation that deviated from evidence-based practice recommendations. Nodule evaluation that deviated from an evidence-based strategy was associated with biopsy of benign lesions and delays in cancer diagnosis, suggesting a need to improve guideline uptake.

Neuroimaging of Headache: Indications and Controversies

Headache is a common presenting symptom in the ambulatory setting that often prompts imaging. The increased use and associated health care money spent in the setting of headache have raised questions about the cost-effectiveness of neuroimaging in this setting. Neuroimaging for headache in most cases is unlikely to reveal significant abnormality or impact patient management. In this article, reasons behind an observed increase in neuroimaging and its impact on health care expenditures are discussed. The typical imaging modalities available and various imaging guidelines for common clinical headache scenarios are presented, including recommendations from the American College of Radiology.

Abdominal Pain in the Emergency Department: How to Select the Correct Imaging for Diagnosis

Abdominal pain is a common presenting complaint in the emergency department, and utilization of diagnostic imaging is often a key tool in determining its etiology. Plain radiography has limited utility in this population. Computed tomography (CT) is the imaging modality of choice for undifferentiated abdominal pain. Ultrasound and magnetic resonance imaging may be helpful in specific scenarios, primarily in pediatrics and pregnancy, and offer the benefit of eliminating ionizing radiation risk of CT. Guidance for imaging selection is determined by location of pain, special patient considerations, and specific suspected etiologies. Expert guidance is offered by the American College of Radiology Appropriateness Criteria^® which outlines imaging options based on location of pain.

Modern Diagnostic Imaging Technique Applications and Risk Factors in the Medical Field: A Review

Medical imaging is the process of visual representation of different tissues and organs of the human body to monitor the normal and abnormal anatomy and physiology of the body. There are many medical imaging techniques used for this purpose such as X-ray, computed tomography (CT), positron emission tomography (PET), magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT), digital mammography, and diagnostic sonography. These advanced medical imaging techniques have many applications in the diagnosis of myocardial diseases, cancer of different tissues, neurological disorders, congenital heart disease, abdominal illnesses, complex bone fractures, and other serious medical conditions. There are benefits as well as some risks to every imaging technique. There are some steps for minimizing the radiation exposure risks from imaging techniques. Advance medical imaging modalities such as PET/CT hybrid, three-dimensional ultrasound computed tomography (3D USCT), and simultaneous PET/MRI give high resolution, better reliability, and safety to diagnose, treat, and manage complex patient abnormalities. These techniques ensure the production of new accurate imaging tools with improving resolution, sensitivity, and specificity. In the future, with mounting innovations and advancements in technology systems, the medical diagnostic field will become a field of regular measurement of various complex diseases and will provide healthcare solutions.

Guidelines for Reasonable and Appropriate Care in the Emergency Department 2 (GRACE-2): Low-risk, recurrent abdominal pain in the emergency department

This second Guideline for Reasonable and Appropriate Care in the Emergency Department (GRACE-2) from the Society for Academic Emergency Medicine is on the topic "low-risk, recurrent abdominal pain in the emergency department." The multidisciplinary guideline panel applied the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess the certainty of evidence and strength of recommendations regarding four priority questions for adult emergency department patients with low-risk, recurrent, undifferentiated abdominal pain. The intended population includes adults with multiple similar presentations of abdominal signs and symptoms recurring over a period of months or years. The panel reached the following recommendations: (1) if a prior negative computed tomography of the abdomen and pelvis (CTAP) has been performed within 12 months, there is insufficient evidence to accurately identify populations in whom repeat CTAP imaging can be safely avoided or routinely recommended; (2) if CTAP with IV contrast is negative, we suggest against ultrasound unless there is concern for pelvic or biliary pathology; (3) we suggest that screening for depression and/or anxiety may be performed during the ED evaluation; and (4) we suggest an opioid-minimizing strategy for pain control. EXECUTIVE SUMMARY: The GRACE-2 writing group developed clinically relevant questions to address the care of adult patients with low-risk, recurrent, previously undifferentiated abdominal pain in the emergency department (ED). Four patient-intervention-comparison-outcome-time (PICOT) questions were developed by consensus of the writing group, who performed a systematic review of the literature and then synthesized direct and indirect evidence to formulate recommendations, following GRADE methodology. The writing group found that despite the commonality and relevance of these questions in emergency care, the quantity and quality of evidence were very limited, and even fundamental definitions of the population and outcomes of interest are lacking. Future research opportunities include developing precise and clinically relevant definitions of low-risk, recurrent, undifferentiated abdominal pain and determining the scope of the existing populations in terms of annual national ED visits for this complaint, costs of care, and patient and provider preferences.

e Silva L, Bellolio F, Upadhye S, Broder JS. Repeat computed tomography in recurrent abdominal pain: An evidence synthesis for guidelines for reasonable and appropriate care in the emergency department

OBJECTIVE

Computed tomography (CT) imaging is frequently obtained for recurrent abdominal pain after a prior emergency department (ED) evaluation. We evaluate the utility of repeat CT imaging following an indeterminate index CT in low-risk abdominal pain adult ED patients.

METHODS

An electronic search was designed for the patient-intervention-control-outcome-timing (PICOT) question: (P) adult patients with low-risk, recurrent, and previously undifferentiated atraumatic abdominal pain presenting to the ED after an index-negative CT within 12 months; (I) repeat CT versus (C) no repeat CT; for (O) abdominal surgery or other invasive procedure, mortality, identification of potentially life-threatening diagnosis, and hospital and intensive care unit admission rates; and return ED visit (T), all within 30 days. Four reviewers independently selected evidence for inclusion and then synthesized the results around the most prevalent themes of repeat CT timing, diagnostic yield, ionizing radiation exposure, and predictors of repetitive imaging.

RESULTS

Although 637 articles and abstracts were identified, no direct evidence was found. Thirteen documents were synthesized as indirect evidence. None of the indirect evidence defined a low-risk subset of abdominal pain nor did investigators describe whether reimaging occurred for complaints similar to the initial ED evaluation. Included studies did not describe the index CT findings and some reported explanatory findings noted on the original CT for which repeat CTs might have been indicated. The time frame for a repeat CT ranged from hours to 1 year. The frequency of repeat CTs (2%-47%) varied across studies as did the yield of imaging to alter downstream clinical decision making (range = 5%-67%).

CONCLUSION

Due to the absence of direct evidence our scoping review is unable to provide high-quality evidence-based recommendations upon which to confidently base an imaging practice guideline. There is no evidence to support or refute performing a CT for low-risk recurrent abdominal pain.

Trends in the Management of Headache Disorders in US Emergency Departments: Analysis of 2007-2018 National Hospital Ambulatory Medical Care Survey Data

We examined trends in management of headache disorders in United States (US) emergency department (ED) visits. We conducted a cross-sectional study using 2007−2018 National Hospital Ambulatory Medical Care Survey data. We included adult patient visits (≥18 years) with a primary ED discharge diagnosis of headache. We classified headache medications by pharmacological group: opioids, butalbital, ergot alkaloids/triptans, acetaminophen/nonsteroidal anti-inflammatory drugs (NSAIDs), antiemetics, diphenhydramine, corticosteroids, and intravenous fluids. To obtain reliable estimates, we aggregated data into three time periods: 2007−2010, 2011−2014, and 2015−2018. Using multivariable logistic regression, we examined medication, neuroimaging, and outpatient referral trends, separately. Among headache-related ED visits, opioid use decreased from 54.1% in 2007−2010 to 28.3% in 2015−2018 (Ptrend < 0.001). There were statistically significant increasing trends in acetaminophen/NSAIDs, diphenhydramine, and corticosteroids use (all Ptrend < 0.001). Changes in butalbital (6.4%), ergot alkaloid/triptan (4.7%), antiemetic (59.2% in 2015−2018), and neuroimaging (37.3%) use over time were insignificant. Headache-related ED visits with outpatient referral for follow-up increased slightly from 73.3% in 2007−2010 to 79.7% in 2015−2018 (Ptrend = 0.02). Reflecting evidence-based guideline recommendations for headache management, opioid use substantially decreased from 2007 to 2018 among US headache-related ED visits. Future studies are warranted to identify strategies to promote evidence-based treatment for headaches (e.g., sumatriptan, dexamethasone) and appropriate outpatient referral and reduce unnecessary neuroimaging orders in EDs.

Approach to Loss of Consciousness: Distinguishing Epileptic Seizures, Psychogenic Nonepileptic Seizures, and Syncope

Transient loss of consciousness (TLOC) is a common emergent neurological issue, which can be attributed to syncope, epileptic seizures, and psychogenic nonepileptic seizures. The purpose of this article is to outline an approach to diagnosing the most common etiologies of TLOC by focusing on the importance of the history and physical examination, as well as targeted diagnostic tests.

Secondary review reduced inpatient MRI orders and avoidable hospital days

INTRODUCTION

Medical centers have dramatically increased the use of magnetic resonance imaging (MRI). At 2 large academic tertiary care centers in New York City, nearly half of inpatient MRI orders took more than 12 h to complete, delaying patient discharge and increasing avoidable hospital days. We posited that transitioning inpatient MRIs to outpatient facilities, when safe and appropriate, could reduce inpatient MRI orders and avoidable hospital days.

METHODS

We manually reviewed 59 inpatient MRI orders delayed on the estimated date of discharge (EDD). These orders were often delayed due to no standard process to escalate orders for medical reasons or no system to coordinate outpatient orders. We developed a revised workflow involving an automation platform that flagged inpatient MRI orders requested within 24 h of the EDD and emailed the care team to request a second review of the order. The care team reconsidered whether the order was (1) required for discharge, (2) non-urgent and could be converted to an outpatient order, or (3) unnecessary and could be canceled.

RESULTS

Over 9 months, the automation platform flagged 618 inpatient MRI orders, of which 53.9% (333/618) were reviewed by the care team. Among the orders, 24.0% (80/333) of reviewed orders and 12.9% (80/618) of all orders were transitioned to either outpatient or canceled orders. These transitioned orders were associated with 267 fewer avoidable hospital days and a cost savings of $199,194.

CONCLUSION

A standardized process and second review of inpatient MRI orders on the EDD can reduce inappropriate orders and more effectively use inpatient imaging resources.

PRECIS

A standardized workflow and automation platform encouraged a second review of inpatient MRI orders to reduce inappropriate orders, avoidable hospital days, and hospital costs.

Accuracy and Clinical Utility of Reports from Outside Hospitals for CT of the Cervical Spine in Blunt Trauma

BACKGROUND AND PURPOSE

Multidetector CT is the workhorse for detecting blunt cervical spine injury. There is no standard of care for re-interpretation of radiology images for patients with blunt trauma transferred to a higher level of care. The clinical impact of discrepancies of cervical spine CT reads remains unclear. We evaluated the discordance between primary (from referring hospitals) and secondary radiology interpretations (from a receiving level I tertiary trauma center) of cervical spine CT scans in patients with blunt trauma and assessed the clinical implications of missed cervical spine fractures.

MATERIALS AND METHODS

Medical records of patients with blunt trauma transferred to our institution between 2008 and 2015 were reviewed. Primary and secondary interpretations were compared and categorized as concordant and discordant. Two senior neuroradiologists adjudicated discordant reports. The benefit of re-interpretation was determined. For discordant cases, outcomes at discharge, injury severity pattern, treatment, and arrival in a cervical collar were assessed.

RESULTS

Six hundred fifty patients were included; 608 (94%) presented with concordant reports: 401 (61.7%) with fractures and 207 (31.8%) with no fractures. There were 42 (6.5%) discordant reports; 18 (2.8%) were cervical spine injuries undetected on the primary interpretation. Following adjudication, the secondary interpretation improved the sensitivity (99.3% versus 95.7%) and specificity (99.1% versus 91.7%) in detecting cervical spine fractures compared with the primary interpretation alone (P < .001).

CONCLUSIONS

There was an overall 6.5% discordance rate between primary and secondary interpretations of cervical spine CT scans. The secondary interpretation of the cervical spine CT increased the sensitivity and specificity of detecting cervical spine fractures in patients with blunt trauma transferred to higher-level care.

Radiation risk issues in recurrent imaging

Millions of patients benefit from medical imaging every single day. However, we have entered an unprecedented era in imaging practices wherein 1 out of 125 patients can be exposed to effective dose >50 mSv from a single CT exam and 3 out of 10,000 patients undergoing CT exams could potentially receive cumulative effective doses > 100 mSv in a single day. Recurrent imaging with CT, fluoroscopically guided interventions, and hybrid imaging modalities such as positron emission tomography/computed tomography (PET/CT) is more prevalent today than ever before. Presently, we do not know the cumulative doses that patients may be receiving across all imaging modalities combined. Furthermore, patients with diseases with longer life expectancies are being exposed to high doses of radiation enabling radiation effects to manifest over a longer time period. The emphasis in the past on improving justification of imaging and optimization of technique and practice has proved useful. While that must continue, the current situation requires imaging device manufacturers to urgently develop imaging technologies that are safer for patients as high doses have been observed in patients where imaging has been justified through clinical decision-support and optimized by keeping doses below the national benchmark doses. There is a need to have a critical look at the fundamental principles of radiation protection as cumulative doses are likely to increase in the coming years.

The Financial and Radiation Burden of Early Reimaging in Neurosurgical Patients: An Original Study and Review of the Literature

The computed tomographic (CT) scanner has become ubiquitous in healthcare. When trauma patients are imaged at facilities not equipped to care for them, imaging is often repeated at the receiving institution. CTs have clinical, financial, and resource costs, and eliminating unnecessary imaging will benefit patients, providers, and institutions. This paper reviews patterns of repetition of CT scans for transferred trauma patients and motivations underlying such behaviors via analysis of our Trauma Registry database and literature published in this area. Neurosurgeons are fundamentally impactful in this decision-making process. The most commonly repeated scan is a CT head (CTH). More than ¼ of our patients receiving a clinically indicated repeat CTH also had a repeat scan of their cervical spine with no reason given for the cervical scan. Herein, we discuss our findings that both non-trauma center practitioners and non-neurosurgical staff at trauma centers cite a lower level of comfort with neuroradiology and fear of litigation as motivators in overzealous neuroimaging. As a result, inappropriate neurosurgical imaging is routinely ordered prior to transfer and again upon arrival at trauma centers. Education of non-neurosurgical staff is essential to prevent inappropriate neuroaxis imaging.

Trends and risk factors for opioid administration for non-emergent lower back pain

BACKGROUND

Non-emergent low-back pain (LBP) is one of the most prevalent presenting complaints to the emergency department (ED) and has been shown to contribute to overcrowding in the ED as well as diverting attention away from more serious complaints. There has been an increasing focus in current literature regarding ED admission and opioid prescriptions for general complaints of pain, however, there is limited data concerning the trends over the last decade in ED admissions for non-emergent LBP as well as any subsequent opioid prescriptions by the ED for this complaint.

AIM

To determine trends in non-emergent ED visits for back pain; annual trends in opioid administration for patients presenting to the ED for back pain; and factors associated with receiving an opioid-based medication for non-emergent LBP in the ED

METHODS

Patients presenting to the ED for non-emergent LBP from 2010 to 2017 were retrospectively identified from the National Hospital Ambulatory Medical Care Survey database. The “year” variable was transformed to two-year intervals, and a weighted survey analysis was conducted utilizing the weighted variables to generate incidence estimates. Bivariate statistics were used to assess differences in count data, and logistic regression was performed to identify factors associated with patients being discharged from the ED with narcotics. Statistical significance was set to a P value of 0.05.

RESULTS

Out of a total of 41658475 total ED visits, 3.8% (7726) met our inclusion and exclusion criteria. There was a decrease in the rates of non-emergent back pain to the ED from 4.05% of all cases during 2010 and 2011 to 3.56% during 2016 and 2017. The most common opioids prescribed over the period included hydrocodone-based medications (49.1%) and tramadol-based medications (16.9), with the combination of all other opioid types contributing to 35.7% of total opioids prescribed. Factors significantly associated with being prescribed narcotics included age over 43.84-years-old, higher income, private insurance, the obtainment of radiographic imaging in the ED, and region of the United States (all, P < 0.05). Emergency departments located in the Midwest [odds ratio (OR): 2.42, P < 0.001], South (OR: 2.35, < 0.001), and West (OR: 2.57, P < 0.001) were more likely to prescribe opioid-based medications for non-emergent LBP compared to EDs in the Northeast.

CONCLUSION

From 2010 to 2017, there was a significant decrease in the number of non-emergent LBP ED visits, as well as a decrease in opioids prescribed at these visits. These findings may be attributed to the increased focus and regulatory guidelines on opioid prescription practices at both the federal and state levels. Since non-emergent LBP is still a highly common ED presentation, conclusions drawn from opioid prescription practices within this cohort is necessary for limiting unnecessary ED opioid prescriptions.

Sarcopenia measured with paraspinous muscle using computed tomography for predicting prognosis in elderly pneumonia patients

Background:

In the elderly, diagnostic findings of pneumonia are often atypical. Computed tomography was recommended for the diagnosis of pneumonia in elderly patients. Recently, the usage of computed tomography as a screening tool for pneumonia in emergency departments has increased. Sarcopenia is defined as the loss of skeletal muscle mass and strength with aging. In this study, the association between sarcopenia and prognosis measured through computed tomography was evaluated compared to CURB-65.

Methods:

This study was conducted on patients diagnosed with pneumonia through computed tomography from 1 March 2018 to 31 March 2020. The paraspinous muscle size and attenuation were measured at a level located at the T12 pedicle level on axial computed tomography images. Paraspinous muscle size was presented as paraspinous muscle index. Differences in the prognostic performance among the paraspinous muscle size and attenuation, and CURB-65 were evaluated by the area under the receiver operating characteristic curve.

Results:

A total of 509 patients were included and 132 patients (25.9%) were admitted to the ICU, and 58 patients (11.4%) died in hospital. Paraspinous muscle index was the significant factor for predicting in-hospital mortality and ICU admission. The area under the receiver operating characteristic value of paraspinous muscle index for prediction of mortality was 0.738 and CURB-65 was 0.707. The area under the receiver operating characteristic of paraspinous muscle index and CURB-65 for predicting ICU admission were 0.766 and 0.704, respectively.

Conclusion:

As a method of measuring sarcopenia, paraspinous muscle index was superior to CURB-65 in elderly pneumonia patients. The use of computed tomography in predicting prognosis for elderly pneumonia patients will ease the economic burden.

Increasing Utilization of Emergency Department Neuroimaging from 2007 to 2017

Background: The volume of emergency department (ED) visits and neuroimaging have grown since the start of the century. Little is known about this growth in the commercially insured and Medicare Advantage populations. Objective: To evaluate changing emergency department utilization of neuroimaging from 2007 to 2017 in both commercially insured and Medicare Advantage enrollees. Methods: Using patient-level claims from Optum's De-identified Clinformatics Data Mart database, which annually includes approximately 12 to 14 million commercial and Medicare Advantage health plan enrollees, annual ED utilization of head computed tomography (CT), head magnetic resonance (MR), head CT angiography (CTA), neck CTA, head MR angiography (MRA), neck MRA, and carotid duplex ultrasound (CDUS) were assessed from 2007 through 2017. To account for an aging sample population, utilization rates were adjusted using annual relative proportions of age groups and stratified by patient demographics, payer type, and provider state. Results: Between 2007 and 2017, age-adjusted ED neuroimaging utilization rates per 1000 ED visits increased 72% overall (compound annual growth rate [CAGR] 5%). This overall increase corresponded to an increase of 69% for head CT (CAGR 5%); 67% for head MRI (CAGR 5%); 1100% for head CTA (CAGR 25%); 1300% for neck CTA (CAGR 27%); 36% for head MRA (CAGR 3%); 52% for neck MRA (CAGR 4%); and a decrease of 8% for CDUS (CAGR -1%). The utilization of head CT and CTA of the head and neck per 1000 ED visits continuously increased in those 65 or older by 48% (CAGR 4%) and 1011% (CAGR 24%). Conclusion: Neuroimaging utilization in the ED grew considerably between 2007 and 2017, with growth of head and neck CTA far outpacing other modalities. Unenhanced head CT remains by far the dominant ED neuroimaging examination. Clinical Impact: The rapid growth of head and neck CTA observed in the fee-for-service Medicare population is also observed in the commercially insured and Medicare Advantage populations. The appropriateness of this growth should be monitored as the indications for CTA expand.

Diagnostic Accuracy and Failure Mode Analysis of a Deep Learning Algorithm for the Detection of Cervical Spine Fractures

BACKGROUND AND PURPOSE

Artificial intelligence decision support systems are a rapidly growing class of tools to help manage ever-increasing imaging volumes. The aim of this study was to evaluate the performance of an artificial intelligence decision support system, Aidoc, for the detection of cervical spinal fractures on noncontrast cervical spine CT scans and to conduct a failure mode analysis to identify areas of poor performance.

MATERIALS AND METHODS

This retrospective study included 1904 emergent noncontrast cervical spine CT scans of adult patients (60 [SD, 22] years, 50.3% men). The presence of cervical spinal fracture was determined by Aidoc and an attending neuroradiologist; discrepancies were independently adjudicated. Algorithm performance was assessed by calculation of the diagnostic accuracy, and a failure mode analysis was performed.

RESULTS

Aidoc and the neuroradiologist's interpretation were concordant in 91.5% of cases. Aidoc correctly identified 67 of 122 fractures (54.9%) with 106 false-positive flagged studies. Diagnostic performance was calculated as the following: sensitivity, 54.9% (95% CI, 45.7%-63.9%); specificity, 94.1% (95% CI, 92.9%-95.1%); positive predictive value, 38.7% (95% CI, 33.1%-44.7%); and negative predictive value, 96.8% (95% CI, 96.2%-97.4%). Worsened performance was observed in the detection of chronic fractures; differences in diagnostic performance were not altered by study indication or patient characteristics.

CONCLUSIONS

We observed poor diagnostic accuracy of an artificial intelligence decision support system for the detection of cervical spine fractures. Many similar algorithms have also received little or no external validation, and this study raises concerns about their generalizability, utility, and rapid pace of deployment. Further rigorous evaluations are needed to understand the weaknesses of these tools before widespread implementation.

Accuracy of emergency physicians' self-estimates of CT scan utilization and its potential effect on an audit and feedback intervention: a randomized trial

BACKGROUND

Audit and feedback (A&F) has been used as a strategy to modify clinician behavior with moderate success. Although A&F is theorized to work by improving the accuracy of clinicians' estimates of their own behavior, few interventions have included assessment of clinicians' estimates at baseline to examine whether they account for intervention success or failure. We tested an A&F intervention to reduce computed tomography (CT) ordering by emergency physicians, while also examining the physicians' baseline estimates of their own behavior compared to peers.

METHODS

Our study was a prospective, multi-site, 20-month, randomized trial to examine the effect of an A&F intervention on CT ordering rates, overall and by test subtype. From the electronic health record, we obtained 12 months of baseline CT ordering per 100 patients treated for every physician from four emergency departments. Those who were randomized to receive A&F were shown a de-identified graph of the group's baseline CT utilization, asked to estimate wherein the distribution of their own CT order practices fell, and then shown their actual performance. All participants also received a brief educational intervention. CT ordering rates were collected for all physicians for 6 months after the intervention. Pre-post ordering rates were compared using independent and repeated measures t tests.

RESULTS

Fifty-one of 52 eligible physicians participated. The mean CT ordering rate increased significantly in both experimental conditions after the intervention (intervention pre = 35.7, post = 40.3, t = 4.13, p < 0.001; control pre = 33.9, post = 38.9, t = 3.94, p = 0.001), with no significant between-group difference observed at follow-up (t = 0.43, p = 0.67). Within the intervention group, physicians had poor accuracy in estimating their own ordering behavior at baseline: most overestimated and all guessed that they were in the upper half of the distribution of their peers. CT ordering increased regardless of self-estimate accuracy.

CONCLUSIONS

Our A&F intervention failed to reduce physician CT ordering: our feedback to the physicians showed most of them that they had overestimated their CT ordering behavior, and they were therefore unlikely to reduce it as a result. After "audit," it may be prudent to assess baseline clinician awareness of behavior before moving toward a feedback intervention.

Deep learning-based automated detection of pulmonary embolism on CT pulmonary angiograms: No significant effects on report communication times and patient turnaround in the emergency department nine months after technical implementation

OBJECTIVES

Rapid communication of CT exams positive for pulmonary embolism (PE) is crucial for timely initiation of anticoagulation and patient outcome. It is unknown if deep learning automated detection of PE on CT Pulmonary Angiograms (CTPA) in combination with worklist prioritization and an electronic notification system (ENS) can improve communication times and patient turnaround in the Emergency Department (ED).

METHODS

In 01/2019, an ENS allowing direct communication between radiology and ED was installed. Starting in 10/2019, CTPAs were processed by a deep learning (DL)-powered algorithm for detection of PE. CTPAs acquired between 04/2018 and 06/2020 (n = 1808) were analysed. To assess the impact of the ENS and the DL-algorithm, radiology report reading times (RRT), radiology report communication time (RCT), time to anticoagulation (TTA), and patient turnaround times (TAT) in the ED were compared for three consecutive time periods. Performance measures of the algorithm were calculated on a per exam level (sensitivity, specificity, PPV, NPV, F1-score), with written reports and exam review as ground truth.

RESULTS

Sensitivity of the algorithm was 79.6 % (95 %CI:70.8-87.2%), specificity 95.0 % (95 %CI:92.0-97.1%), PPV 82.2 % (95 %CI:73.9-88.3), and NPV 94.1 % (95 %CI:91.4-96 %). There was no statistically significant reduction of any of the observed times (RRT, RCT, TTA, TAT).

CONCLUSION

DL-assisted detection of PE in CTPAs and ENS-assisted communication of results to referring physicians technically work. However, the mere clinical introduction of these tools, even if they exhibit a good performance, is not sufficient to achieve significant effects on clinical performance measures.

Validation of a clinical decision instrument for emergent neuroimaging after a seizure: Let's image malignancy, intracranial hemorrhage, and trauma (LIMIT)

BACKGROUND

Given the many causes of seizures, emergency physicians often utilize brain computed tomography (CT) to evaluate for intracranial pathology. However, a CT exposes patients to 100 times more radiation than a chest radiograph. Previously, we developed a four-item clinical decision instrument (CDI) to determine which patients with status epilepticus (SE) do not require emergent neuroimaging. In this study, we seek to prospectively validate our CDI in patients with a history of seizures with both SE and generalized tonic-clonic seizures.

METHODS

This was a prospective observational study of 1,739 consecutive patients who were recruited from two urban hospitals in Philadelphia, Pennsylvania. All patients, 18 years and older, who presented with a chief complaint of seizure and had emergency neuroimaging performed were eligible for inclusion. Patients were excluded from analysis if this was a first-time seizure, had a ventriculoperitoneal shunt, or had focal neurologic deficits.

RESULTS

A total of 376 patients were in the final analysis. Of the 376 patients, 10 patients (3%) had positive CTs. Nine of the 10 of the patients were identified by our CDI, resulting in a negative predictive value (NPV) of 99.5%. On secondary analysis, we refined our CDI from four to three criteria: 1) history of intracranial hemorrhage (ICH), 2) active malignancy, and 3) trauma. These criteria also had a NPV of >99% when applied to patients in SE.

CONCLUSION

The validation of our CDI showed improved NPV when compared to the derivation set. Use of the criteria of history of ICH, active malignancy, and trauma could have reduced the use of emergent neuroimaging in our cohort by up to 49%. This CDI should be validated in a larger subset of patients and in multiple centers prior to widespread adoption.

Diagnostic Accuracy and Failure Mode Analysis of a Deep Learning Algorithm for the Detection of Intracranial Hemorrhage

OBJECTIVE

To determine the institutional diagnostic accuracy of an artificial intelligence (AI) decision support systems (DSS), Aidoc, in diagnosing intracranial hemorrhage (ICH) on noncontrast head CTs and to assess the potential generalizability of an AI DSS.

METHODS

This retrospective study included 3,605 consecutive, emergent, adult noncontrast head CT scans performed between July 1, 2019, and December 30, 2019, at our institution (51% female subjects, mean age of 61 ± 21 years). Each scan was evaluated for ICH by both a certificate of added qualification certified neuroradiologist and Aidoc. We determined the diagnostic accuracy of the AI model and performed a failure mode analysis with quantitative CT radiomic image characterization.

RESULTS

Of the 3,605 scans, 349 cases of ICH (9.7% of studies) were identified. The neuroradiologist and Aidoc interpretations were concordant in 96.9% of cases and the overall sensitivity, specificity, positive predictive value, and negative predictive value were 92.3%, 97.7%, 81.3%, and 99.2%, respectively, with positive predictive values unexpectedly lower than in previously reported studies. Prior neurosurgery, type of ICH, and number of ICHs were significantly associated with decreased model performance. Quantitative image characterization with CT radiomics failed to reveal significant differences between concordant and discordant studies.

DISCUSSION

This study revealed decreased diagnostic accuracy of an AI DSS at our institution. Despite extensive evaluation, we were unable to identify the source of this discrepancy, raising concerns about the generalizability of these tools with indeterminate failure modes. These results further highlight the need for standardized study design to allow for rigorous and reproducible site-to-site comparison of emerging deep learning technologies.

Acute Kidney Injury After CT in Emergency Patients with Chronic Kidney Disease: A Propensity Score-matched Analysis

INTRODUCTION

Acute kidney injury (AKI) after intravenous contrast administration for computed tomography (CT) occurs infrequently, but certain patients may be susceptible. This study evaluated AKI incidence among emergency department (ED) patients with pre-existing chronic kidney disease (CKD) undergoing CT exams.

METHODS

This retrospective cohort study in an integrated healthcare system included ED patients previously diagnosed with CKD stages 3-5 (estimated glomerular filtration rate <60 milliliters per minute per 1.73 meters squared over at least three months), undergoing CT exams with or without intravenous contrast, from January 1, 2013-December 31, 2017. We excluded patients with CT prior to (30 days) or following (14 days) index CT and missing serum creatinine (sCr) measurements. We applied propensity score matching, and then multivariable regression adjustment for post-CT ED disposition and ED diagnosis, to calculate adjusted risk of AKI. Secondary patient-centered outcomes included 30-day mortality, end-stage renal disease (ESRD) diagnosis, and dialysis initiation.

RESULTS

Among 103,573 eligible ED patients undergoing CT, propensity score matching yielded 5,589 pairs. Adjusted risk ratio (ARR) for AKI was higher overall for contrast-enhanced CT (1.60; 95% confidence interval [CI], 1.43-1.79). However, secondary outcomes were infrequent: 19/5,589 non-contrast vs 40/5,589 contrast patients with new dialysis initiation at 30 days (adjusted risk 0.3% vs 0.7%; adjusted risk reduction 0.4%; 95% CI, 0.1%-0.7%).

CONCLUSION

In ED patients with chronic kidney disease undergoing CT, intravenous contrast was associated with higher overall adjusted risk of AKI, but patient-centered secondary outcomes were rare. The clinical significance of transient kidney injury after CT is unclear, although patients with advanced chronic kidney disease appear to have elevated risk.

CT Attenuation Values Do Not Reliably Distinguish Benign Sclerotic Lesions From Osteoblastic Metastases in Patients Undergoing Bone Biopsy

BACKGROUND. CT attenuation thresholds that accurately distinguish enostoses from untreated osteoblastic metastases have been published. In the Mayo Clinic practices, these thresholds have been applied more broadly to distinguish benign sclerotic bone lesions other than enostoses from osteoblastic metastases. OBJECTIVE. The purpose of this article is to determine if CT attenuation thresholds allow the distinguishing of benign sclerotic bone lesions from osteoblastic metastases in patients undergoing bone biopsy. METHODS. A retrospective search was conducted to identify sclerotic lesions described on CT between October 7, 1998, and July 15, 2018, that underwent subsequent biopsy. Two musculoskeletal radiologists recorded lesions' maximum and mean attenuation. Using previously published attenuation thresholds, sensitivity and specificity for differentiating benign sclerotic lesions from osteoblastic metastases were calculated. ROC curve analysis was performed to determine if more appropriate attenuation thresholds exist. Intraclass correlation coefficients (ICCs) were computed. RESULTS. A total of 280 patients met inclusion criteria. Of those, 162 had malignant biopsy results and 118 had benign biopsy results. Of the 162 malignant lesions, 81 had received prior treatment. Maximum and mean attenuation were not significantly different between benign and malignant lesions for either reader (all p > .05). For reader 1, to distinguish benign from malignant lesions, a maximum attenuation threshold of more than 1060 HU resulted in sensitivity of 23.7%, specificity of 87.0%, and accuracy of 60.6%. A mean attenuation threshold of greater than 885 HU resulted in sensitivity of 19.5%, specificity of 90.7%, and accuracy 60.7%. ROC curve analysis showed AUCs for mean and maximum attenuation thresholds of 51.8% and 54.6%, respectively. Subgroup analyses of benign versus malignant and treated versus untreated lesions had similar results. Similar findings were obtained for reader 2. The two readers' ICC was 0.946 for maximum attenuation and 0.918 for mean attenuation. CONCLUSION. Published attenuation thresholds for distinguishing enostoses from osteoblastic metastases had slightly decreased specificity and markedly decreased sensitivity when applied to the differentiation of benign sclerotic lesions from osteoblastic metastases in our sample of biopsy-proven lesions. ROC analysis showed no high-performing attenuation threshold alternative. CLINICAL IMPACT. Published CT attenuation thresholds intended for distinguishing enostoses from osteoblastic metastases should not be used more broadly. More accurate alternative thresholds could not be derived.

Text Messaging and Web-Based Survey System to Recruit Patients With Low Back Pain and Collect Outcomes in the Emergency Department: Observational Study

BACKGROUND

Low back pain (LBP) is a frequent reason for emergency department (ED) presentations, with a global prevalence of 4.4%. Despite being common, the number of clinical trials investigating LBP in the ED is low. Recruitment of patients in EDs can be challenging because of the fast-paced and demanding ED environment.

OBJECTIVE

The aim of this study is to describe the recruitment and response rates using an SMS text messaging and web-based survey system supplemented by telephone calls to recruit patients with LBP and collect health outcomes in the ED.

METHODS

An automated SMS text messaging system was integrated into Research Electronic Data Capture and used to collect patient-reported outcomes for an implementation trial in Sydney, Australia. We invited patients with nonserious LBP who presented to participating EDs at 1, 2, and 4 weeks after ED discharge. Patients who did not respond to the initial SMS text message invitation were sent a reminder SMS text message or contacted via telephone. The recruitment rate was measured as the proportion of patients who agreed to participate, and the response rate was measured as the proportion of participants completing the follow-up surveys at weeks 2 and 4. Regression analyses were used to explore factors associated with response rates.

RESULTS

In total, 807 patients with nonserious LBP were invited to participate and 425 (53.0%) agreed to participate. The week 1 survey was completed by 51.5% (416/807) of participants. At week 2, the response rate was 86.5% (360/416), and at week 4, it was 84.4% (351/416). Overall, 60% of the surveys were completed via SMS text messaging and on the web and 40% were completed via telephone. Younger participants and those from less socioeconomically disadvantaged areas were more likely to respond to the survey via the SMS text messaging and web-based system.

CONCLUSIONS

Using an SMS text messaging and web-based survey system supplemented by telephone calls is a viable method for recruiting patients with LBP and collecting health outcomes in the ED. This hybrid system could potentially reduce the costs of using traditional recruitment and data collection methods (eg, face-to-face, telephone calls only).

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1136/bmjopen-2017-019052.

Patient Race/Ethnicity and Diagnostic Imaging Utilization in the Emergency Department: A Systematic Review

PURPOSE

Diagnostic imaging often is a critical contributor to clinical decision making in the emergency department (ED). Racial and ethnic disparities are widely reported in many aspects of health care, and several recent studies have reported a link between patient race/ethnicity and receipt of imaging in the ED.

METHODS

The authors conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, searching three databases (PubMed, Embase, and the Cochrane Library) through July 2020 using keywords related to diagnostic imaging, race/ethnicity, and the ED setting, including both adult and pediatric populations and excluding studies that did not control for the important confounders of disease severity and insurance status.

RESULTS

The search strategy identified 7,313 articles, of which 5,668 underwent title and abstract screening and 238 full-text review, leaving 42 articles meeting the inclusion criteria. Studies were predominately conducted in the United States (41), split between adult (13) and pediatric (17) populations or both (12), and spread across a variety of topics, mostly focusing on specific anatomic regions or disease processes. Most studies (30 of 42 [71.4%]) reported an association between Black, African American, Hispanic, or nonwhite race/ethnicity and decreased receipt of imaging.

CONCLUSIONS

Despite heterogeneity among studies, patient race/ethnicity is linked with receipt of diagnostic imaging in the ED. The strength and directionality of this association may differ by specific subpopulation and disease process, and more efforts to understand potential underlying factors are needed.

Trends in Use of Diagnostic Imaging for Abdominal Pain in U.S. Emergency Departments

OBJECTIVE. CT has excellent accuracy for appendicitis but is associated with risks. Research and educational campaigns have been conducted to implement an ultrasound-first strategy for children but not for adults. The purpose of this study was to measure the use of CT and ultrasound in emergency department (ED) visits for abdominal pain and appendicitis to examine the impact of these efforts. MATERIALS AND METHODS. We analyzed data from the National Hospital Ambulatory Medical Care Survey (1997-2016). Use of CT and ultrasound was measured over time in visits for abdominal pain and visits in which appendicitis was diagnosed. Predictors of CT use were identified by means of regression analysis. RESULTS. For children, CT use increased from 1.2% (95% CI, 0.6-2.5%) in 1997, peaked in 2010 at 16.6% (95% CI, 13.8-19.6%), and decreased slightly in 2016. In adults, CT use increased steadily from 3.9% in 1997 (95% CI, 3.1-4.8%) to 37.8% (95% CI, 35.5-41.0%) in 2016. CT use increased for both pediatric and adult ED visits with a diagnosis of appendicitis, from 5.2% (95% CI, 0.7-29.5%) to 71.0% (95% CI, 43.1-88.8%) for children and 7.2% (95% CI, 2.7-17.6%) to 83.3% (95% CI, 64.1-93.3%) for adults. Children with abdominal pain and a diagnosis of appendicitis evaluated in a pediatric ED were at decreased odds (pain odds ratio, 0.6 [95% CI, 0.3-0.9]; appendicitis odds ratio, 0.2 [95% CI, 0.0-0.7]) of receiving CT than were those evaluated in general EDs. CONCLUSION. CT use has decreased in the evaluation of abdominal pain in children, perhaps because of research findings and efforts to implement an ultrasound-first strategy for suspected appendicitis. In contrast, CT use has continued to increase among adults with abdominal pain in EDs.

Trends in Imaging for Suspected Pulmonary Embolism Across US Health Care Systems, 2004 to 2016

IMPORTANCE

In response to calls to reduce unnecessary diagnostic testing with computed tomographic pulmonary angiography (CTPA) for suspected pulmonary embolism (PE), there have been growing efforts to create and implement decision rules for PE testing. It is unclear if the use of advanced imaging tests for PE has diminished over time.

OBJECTIVE

To assess the use of advanced imaging tests, including chest computed tomography (CT) (ie, all chest CT except for CTPA), CTPA, and ventilation-perfusion (V/Q) scan, for PE from 2004 to 2016.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study of adults by age group (18-64 years and ≥65 years) enrolled in 7 US integrated and mixed-model health care systems. Joinpoint regression analysis was used to identify years with statistically significant changes in imaging rates and to calculate average annual percentage change (growth) from 2004 to 2007, 2008 to 2011, and 2012 to 2016. Analyses were conducted between June 11, 2019, and March 18, 2020.

MAIN OUTCOMES AND MEASURES

Rates of chest CT, CTPA, and V/Q scan by year and age, as well as annual change in rates over time.

RESULTS

Overall, 3.6 to 4.8 million enrollees were included each year of the study, for a total of 52 343 517 person-years of follow-up data. Adults aged 18 to 64 years accounted for 42 223 712 person-years (80.7%) and those 65 years or older accounted for 10 119 805 person-years (19.3%). Female enrollees accounted for 27 712 571 person-years (52.9%). From 2004 and 2016, chest CT use increased by 66.3% (average annual growth, 4.4% per year), CTPA use increased by 450.0% (average annual growth, 16.3% per year), and V/Q scan use decreased by 47.1% (decreasing by 4.9% per year). The use of CTPA increased most rapidly from 2004 to 2006 (44.6% in those aged 18-64 years and 43.9% in those ≥65 years), with ongoing rapid growth from 2006 to 2010 (annual growth, 19.8% in those aged 18-64 years and 18.3% in those ≥65 years) and persistent but slower growth in the most recent years (annual growth, 4.3% in those aged 18-64 years and 3.0% in those ≥65 years from 2010 to 2016). The use of V/Q scanning decreased steadily since 2004.

CONCLUSIONS AND RELEVANCE

From 2004 to 2016, rates of chest CT and CTPA for suspected PE continued to increase among adults but at a slower pace in more contemporary years. Efforts to combat overuse have not been completely successful as reflected by ongoing growth, rather than decline, of chest CT use. Whether the observed imaging use was appropriate or was associated with improved patient outcomes is unknown.

Assessing and coping with the financial burden of computed tomography utilization in Limbe, Cameroon: a sequential explanatory mixed-methods study

BACKGROUND

There has been a significant increase in computed tomography (CT) utilization over the past two decades with the major challenges being a high exposure to ionizing radiation and rising cost. In this study we assess the risk of financial hardship after CT utilization and elaborate on how users adapt and cope in a sub-Saharan context with user fee for services and no national health insurance policy.

METHODS

We carried out a sequential explanatory mixed methods study with a quantitative hospital-based survey of CT users followed by in-depth interviews of some purposively selected participants who reported risk of financial hardship after CT utilization. Data was summarized using frequencies, percentages and 95% confidence intervals. Logistic regression was used in multivariable analysis to determine predictors of risk of financial hardship. Identified themes from in-depth interviews were categorized. Quantitative and qualitative findings were integrated.

RESULTS

A total of 372 participants were surveyed with a male to female sex ratio of 1:1.2. The mean age (standard deviation) was 52(17) years. CT scans of the head and facial bones accounted for 63% (95%CI: 59-68%) and the top three indications were suspected stroke (27% [95%CI: 22-32%]), trauma (14% [95%CI: 10-18%]) and persistent headaches (14% [95%CI: 10-18%]). Seventy-two percent (95%CI: 67-76%) of the respondents reported being at risk of financial hardship after CT utilization and predictors in the multivariable analysis were a low socioeconomic status (aOR: 0.19 [95%CI: 0.10-0.38]; p < 0.001), being unemployed or retired (aOR: 11.75 [95%CI: 2.59-53.18]; p = 0.001) and not having any form of health insurance (aOR: 3.59 [95%CI: 1.31-9.85]; p = 0.013). Coping strategies included getting financial support from family and friends, borrowing money and obtaining discounts from the hospital administration and staff.

CONCLUSION

No health insurance ownership, being unemployed or retired and a low socioeconomic status are associated with financial hardship after CT utilization. Diverse coping strategies are utilized to lessen the financial burden, some with negative consequences. Minimizing out-of-pocket payments and/or the direct cost of CT can reduce this financial burden and improve CT access.