Increasing Utilization of Emergency Department Neuroimaging from 2007 to 2017

Incidence Trends and Risk of Recurrent Stroke of Cervical Artery Dissections in the United States Between 2005 and 2019

BACKGROUND AND OBJECTIVES

Cervical artery dissection (CeAD) is a common cause of acute ischemic stroke (AIS), especially in patients younger than 55 years, but data regarding trends and subsequent AIS risk after CeAD remain scarce. We aimed to determine national trends in CeAD admissions and examine post-CeAD risk of ischemic stroke.

METHODS

We used the National Inpatient Sample (2005-2019), National Readmission Database (2015-2019), and State Inpatient Database for New York (2011-2017) and Florida (2011-2019). Adult patients with spontaneous CeAD were identified using International Classification of Diseases, Ninth Revision, Clinical Modification and International Classification of Diseases, Tenth Revision, Clinical Modification codes. Survey-weighted annual CeAD cases were combined with US census data to estimate annual incidence. National estimates were verified with state-level data, which allows for the removal of duplicate admissions for a single patient through a unique patient identifier. Joinpoint regression was used to quantify the average annual percent change (AAPC) of CeAD incidence. AIS readmission risk after CeAD without concurrent AIS was assessed with death as a competing risk using Fine and Gray competing risk methodology.

RESULTS

From 2005 to 2019, we identified 125,102 patients (46.09% female, mean age 51.4 years) with spontaneous CeAD. CeAD incidence increased from 10.7 cases per million population in 2005 to 45.6 cases per million population in 2019, revealing an AAPC of 10.21% (95% CI 9.67%-10.76%). This substantial increase in CeAD admissions was particularly high in the older, Black, and Hispanic populations. Statewide data corroborated this upward trend with an AAPC of 8.47% (95% CI 7.97%-9.48%). Among patients with CeAD without AIS, vertebral artery dissection was the sole major predictor of subsequent ischemic stroke risk within 90 days (adjusted subdistributed hazard ratio 1.77, 95% CI 1.18-2.64, p = 0.006). Interaction and subgroup analyses were performed and demonstrated similar results.

DISCUSSION

There was an almost 5-fold increase in CeAD hospitalizations and an upward incidence trend from 2005 to 2019, particularly in racial minorities, which may be attributed to increased imaging and awareness of CeAD. Our study also revealed a small but significant risk of AIS in patients with vertebral artery dissection without concurrent ischemic stroke. These findings underscore the importance of studying acute treatment and secondary prevention strategies in patients with CeAD.

Fully automated image quality assessment based on deep learning for carotid computed tomography angiography: A multicenter study

PURPOSE

To develop and evaluate the performance of fully automated model based on deep learning and multiple logistics regression algorithm for image quality assessment (IQA) of carotid computed tomography angiography (CTA) images.

METHODS

This study retrospectively collected 840 carotid CTA images from four tertiary hospitals. Three radiologists independently assessed the image quality using a 3-point Likert scale, based on the degree of noise, vessel enhancement, arterial vessel contrast, vessel edge sharpness, and overall diagnostic acceptability. An automated assessment model was developed using a training dataset consisting of 600 carotid CTA images. The assessment steps included: (i) selection of objective representative slices; (ii) use of 3D Res U-net approach to extract objective indices from the representative slices and (iii) use of single objective index and multiple indices combinedly to develop logistic regression models for IQA. In the internal and external test datasets (n = 240), the performance of models was evaluated using sensitivity, specificity, precision, F-score, accuracy, the area under the receiver operating characteristic curve (AUC), and the IQA results of models was compared with radiologists' consensus.

RESULTS

The representative slices were determined based on the same length model. The performance of multi-index model was excellent in internal and external test datasets with AUCs of 0.98 and 0.97. And the consistency between model and radiologists achieved 91.8% (95% CI: 87.0-96.5) and 92.6% (95 % CI: 86.9-98.4) in internal and external test datasets respectively.

CONCLUSION

The fully automated multi-index model showed equivalent performance to the subjective perceptions of radiologists with greater efficiency for IQA.

Bridging the Gap: Evaluation of a Supplemental Surge Staffing Model to Maintain Radiology Turnaround Times Amid Labor Constraints

PURPOSE

Many practices face staffing challenges stemming from expanding clinical volumes and recruitment difficulties. This study aims to evaluate the use of supplemental surge staffing along with scheduled shift redistribution as a bridge to needed staffing increases.

METHODS

A tertiary care academic Emergency Radiology Division comprising 23 radiologists faced a labor shortage during the addition of a new hospital emergency department on June 30, 2023. Strategies to preserve turnaround times (TATs) included increasing daily scheduled shift hours and surge staffing. In surge staffing, scheduled radiologists initiate "surge" calls for assistance during high volumes, prompting available nonscheduled staff to read remotely, with compensation based on length and time of surge engagement. Staff could participate in one or both strategies. Data collected 60 days before and after the emergency room addition compared total relative value units (RVUs), median and 80th percentile TATs, RVUs per person hour, and individual staff surge engagement versus shift increase.

RESULTS

Total RVUs increased by 15% in the post-addition period (38,746 versus 44,628, P < .01), and median TATs (42 versus 44 min, P = .53), 80th percentile TATs (74 versus 73 min, P = .87), and average RVUs per person hour (8.2 versus 8.2, P = .52) did not change significantly. Only 70% (16 of 23) of baseline staff increased scheduled shift hours post-addition, and 96% (22 of 23) engaged in surge staffing. Surge timing and duration varied per individual.

CONCLUSION

A "just-in-time" supplemental surge staffing model, in combination with increasing scheduled shift hours, can be effectively used to maintain TATs during staffing shortages, aiding timely care delivery as a bridge to more permanent staffing solutions.

Forecasting trends of rising emergency department chest imaging using machine learning

INTRODUCTION

Imaging studies in the acute care setting, such as the emergency room, have been increasing. In this report, we use the Centers for Medicare and Medicaid services (CMS) database to assess trends in ED chest CT and chest CTA imaging in ED from 2010 to 2021. In addition, we forecast the utilization of these imaging modalities until 2030 to predict volume of studies using machine learning models.

METHODS

CMS data regarding volume of procedures from 2010 to 2021 for CPT Codes: Chest CT: 71,250, 71,260, 71,270; and Chest CTA 71,275 was obtained. IBM SPSS Statistical Software was used to assess compound annual growth rate (CAGR) to identify trends in ED center (ED) imaging. For predictive time series forecast, and autoregressive integrated moving average (ARIMA) model was constructed using R Studio statistical software. Ljung-Box test was used to check the model's residuals.

RESULTS

Chest CT imaging in the ED setting has steadily increased from 273,063 in 2010 to 540,047 in 2021. Chest CTA imaging also saw an increase from 175,554 in 2010 to 705,727 in 2021. ED Chest CT imaging has increased from 2010 to 2021 with a CAGR of 7.5% (p < 0.001). Similarly, chest CTA imaging has also increased during this period with an average CAGR or 13.0% (p < 0.001). The ARIMA model forecast for ED CT chest imaging predicts a continued increase in volume of CT imaging reaching 614,995 in 2024 and 760,851 in 2030. Chest CTA is predicted to have an even higher increase up to 850,320 in 2024 and 1,139,505 in 2030 assuming the trend observed over the past decade is consistent.

CONCLUSION

From 2010 to 2021, we found an increasing trend in ED chest CT and CTA imaging with forecast predicting volume up to twice of volume in 2030 compared to a decade ago. Understanding the anticipated volumes of forthcoming ED imaging can aid in planning hospital infrastructure, personnel, and funding amongst other required healthcare resources. It is important to consider that while imaging holds a significant role in patient care, inappropriate utilization can result in unnecessary radiation exposure, prolonged wait times, and an increase in burden of healthcare resources.

Epidemiology of traumatic cervical artery dissections

INTRODUCTION

Unlike spontaneous cervical artery dissection (CeAD), the incidence of CeAD after a major trauma is not well characterized. This population-based observational study investigates the epidemiology and natural history of traumatic cervical artery dissection (CeADs) using data from the Rochester Epidemiology Project (REP) in Olmsted County, USA.

METHODS

The REP system database has a high likelihood of complete case ascertainment and comparable demographics (age, sex) to the US population. After the initial screening of the database with ICD-based codes for carotid and vertebral dissections, meticulous review was performed to select patients with CeAD due to major trauma. We used Poisson regression to assess the association of age, sex, and time-period using crude incidence rates.

RESULTS

Analyzing cases from 2002 to 2020, we identified 21 patients with traumatic CeAD, noting a significant 3.5-fold increase in incidence from 2002 to 2011-2012-2020 (0.37-1.29 per 100,000 person-years, p = 0.005). Only 23.8 % of cases experienced traumatic CeAD-related cerebral infarction. No patients received acute reperfusion therapies. Antithrombotic treatment predominantly involved single antiplatelet therapy (47.6 %) with aspirin. However, increasing use of dual antiplatelet therapy (11.8 %) along with declining use of anticoagulation (17.6 %) was also noted over time. We observed no recurrent strokes, dissections, or de-novo pseudoaneurysms. at the final follow-up.

CONCLUSION

The population-based incidence of traumatic CeAD is on the rise, potentially due to an increased screening in real-life practice leading to improved identification of cases that may have otherwise gone unrecognized. Our study also shows that traumatic CeADs tend to have a favorable prognosis.

National trends in catheter angiography and cerebrovascular imaging in a group of privately insured patients in the US

BACKGROUND

Despite the increasing use of non-invasive imaging, DSA remains the gold standard for cerebrovascular imaging. However, trends in DSA utilization are poorly understood. The goal of this study was to describe DSA utilization in a large claims database in the US over a 13 year period.

METHODS

This retrospective cohort study assessed a nationwide database of privately insured individuals from 2005 to 2018 for patients undergoing cranial CT angiography (CTA), MR angiography (MRA), and DSA. We assessed trends in the overall use of and indications for each modality. For DSA, we examined the types of performing proceduralists.

RESULTS

Among patients undergoing DSA in 2018, median age was 52 years, and 60% were women. MRA and DSA use decreased, from 289 to 275 claims, and from 38 to 29 claims per 100 000 enrollees, respectively, while CTA use increased from 31 to 286 claims per 100 000 enrollees. These trends differed by geographic region and indication. Nearly half of DSA procedures but <25% of non-invasive imaging were inpatient studies. DSA performed by neurosurgeons increased from 0.5 to 4.1 while those performed by radiologists decreased from 7.2 to 4.0 studies per 100 000 enrollees.

CONCLUSIONS

DSA use decreased slightly while CTA use increased by ninefold. The reasons for this change are likely complex and may reflect more aggressive imaging for stroke, increased detection of incidental findings, and increased quality of non-invasive imaging. Over time, the proportion of DSA procedures performed by neurosurgeons overtook that performed by radiologists.

Epidemiology of headache presentations to United States emergency departments from 2016 to 2023

INTRODUCTION

Headaches are a common condition seen in the Emergency Department (ED), with numerous trials focused on improving care for these patients. However, there is limited recent large-scale, robust data available on the incidence, admission rates, evaluation, and treatment in the ED setting.

METHODS

This was a cross-sectional study of ED presentations for headache from 1/1/2016 to 12/31/2023 using the Epic Cosmos national database. All ED visits with headache-relevant ICD-10 coding were included. Outcomes included percentage of total ED visits, admission rates, computed tomography (CT) brain imaging, lumbar puncture (LP) performance, and medication administration. Medications were analyzed by class (NSAIDs, acetaminophen, dopamine antagonists, diphenhydramine, opioids, intravenous fluids, caffeine, and magnesium sulfate). Subgroup analyses were performed by specific types of dopamine antagonists.

RESULTS

Of 188,482,644 ED encounters, 6,007,090 (3.2%) were due to headache. Of these, 246,082 (4.1%) were admitted. Nearly half (46.6%) of patients received at least one CT. Rates of CT head without contrast increased from 38.2% to 47.9% over time, while rates of CT angiography rose from 2.8% to 10.2%. 1.4% of all patients received an LP, with rates decreasing from 1.8% to 1.1% over time. The most common medication was NSAIDs (45.3%), followed by dopamine antagonists (44.8%), diphenhydramine (38.1%), acetaminophen (24.8%), opioids (16.3%), magnesium sulfate (0.2%), and caffeine (0.1%). 50.8% of patients received intravenous fluids. Rates of opioids declined over time, while dopamine antagonists, acetaminophen, and intravenous fluid administration increased.

CONCLUSION

Headaches represent a common reason for ED presentation, with approximately 4% of patients being admitted. Imaging is frequently performed, with rises in CT without contrast and CT angiography rates over time, while LP rates have been declining. NSAIDs remain the most common medication given, with opioids declining over time while non-opioid agents such as dopamine antagonists have increased. These findings can help inform health policy initiatives, such as those focused on radiologic imaging and evidence-based medication administration.

Abbreviated MRI in the evaluation of dizziness: report turnaround times and impact on length of stay compared to CT, CTA, and conventional MRI

PURPOSE

Neuroimaging is often used in the emergency department (ED) to evaluate for posterior circulation strokes in patients with dizziness, commonly with CT/CTA due to speed and availability. Although MRI offers more sensitive evaluation, it is less commonly used, in part due to slower turnaround times. We assess the potential for abbreviated MRI to improve reporting times and impact on length of stay (LOS) compared to conventional MRI (as well as CT/CTA) in the evaluation of acute dizziness.

MATERIALS AND METHODS

We performed a retrospective analysis of length of stay via LASSO regression for patients presenting to the ED with dizziness and discharged directly from the ED over 4 years (1/1/2018-12/31/2021), controlling for numerous patient-level and logistical factors. We additionally assessed turnaround time between order and final report for various imaging modalities.

RESULTS

14,204 patients were included in our analysis. Turnaround time for abbreviated MRI was significantly lower than for conventional MRI (4.40 h vs. 6.14 h, p < 0.001) with decreased impact on LOS (0.58 h vs. 2.02 h). Abbreviated MRI studies had longer turnaround time (4.40 h vs. 1.41 h, p < 0.001) and was associated with greater impact on ED LOS than non-contrast CT head (0.58 h vs. 0.00 h), however there was no significant difference in turnaround time compared to CTA head and neck (4.40 h vs. 3.86 h, p = 0.06) with similar effect on LOS (0.58 h vs. 0.53 h). Ordering both CTA and conventional MRI was associated with a greater-than-linear increase in LOS (additional 0.37 h); the same trend was not seen combining CTA and abbreviated MRI (additional 0.00 h).

CONCLUSIONS

In the acute settings where MRI is available, abbreviated MRI protocols may improve turnaround times and LOS compared to conventional MRI protocols. Since recent guidelines recommend MRI over CT in the evaluation of dizziness, implementation of abbreviated MRI protocols has the potential to facilitate rapid access to preferred imaging, while minimizing impact on ED workflows.

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.

Deep Learning Imaging Reconstruction Algorithm for Carotid Dual Energy CT Angiography: Opportunistic Evaluation of Cervical Intervertebral Discs-A Preliminary Study

Thus, the aim of this study is to evaluate the performance of deep learning imaging reconstruction (DLIR) algorithm in different image sets derived from carotid dual-energy computed tomography angiography (DECTA) for evaluating cervical intervertebral discs (IVDs) and compare them with those reconstructed using adaptive statistical iterative reconstruction-Veo (ASiR-V). Forty-two patients who underwent carotid DECTA were included in this retrospective analysis. Three types of image sets (70 keV, water-iodine, and water-calcium) were reconstructed using 50% ASiR-V and DLIR at medium and high levels (DLIR-M and DLIR-H). The diagnostic acceptability and conspicuity of IVDs were assessed using a 5-point scale. Hounsfield Units (HU) and water concentration (WC) values of the IVDs; standard deviation (SD); and coefficient of variation (CV) were calculated. Measurement parameters of the 50% ASIR-V, DLIR-M, and DLIR-H groups were compared. The DLIR-H group showed higher scores for diagnostic acceptability and conspicuity, as well as lower SD values for HU and WC than the ASiR-V and DLIR-M groups for the 70 keV and water-iodine image sets (all p < .001). However, there was no significant difference in scores and SD among the three groups for the water-calcium image set (all p > .005). The water-calcium image set showed better diagnostic accuracy for evaluating IVDs compared to the other image sets. The inter-rater agreement using ASiR-V, DLIR-M, and DLIR-H was good for the 70 keV image set, excellent for the water-iodine and water-calcium image sets. DLIR improved the visualization of IVDs in the 70 keV and water-iodine image sets. However, its improvement on color-coded water-calcium image set was limited.

Multisystem factors contributing to redundant intracranial vascular imaging in the ED

PURPOSE

To evaluate the multisystem factors contributing to redundant neurovascular orders in the ED.

METHODS

This was an IRB-approved, retrospective study, performed at a single institution examining a 5-year history of redundant CTA/MRA head and neck (HN) exams performed in the ED for patients with no documented clinical change in mental status/neurological exam necessitating additional imaging. Factors contributing to redundant ordering including provider experience, synchronous order placement, and radiologist recommendations were examined. Additionally, the impact of duplicative imaging in terms of medical cost and ED length of stay was evaluated.

RESULTS

250 patients met inclusion criteria with both CTA/MRA of the HN performed during a single ED encounter (total 500 exams). 190 (76%) redundant exams were not recommended by a radiologist and contributed to an added ED length of stay of 3.6 h on average. Provider experience was not a significant contributing factor. 60 (24%) of redundant exams were recommended by a radiologist and were most frequently CTAs needed to clarify an area of artifact/high-grade stenosis/occlusion on a primary MRA exam.

CONCLUSION

Evaluation of contributing factors to redundant CTA/MRA HN exams ordering has highlighted multiple associated factors including provider experience, recommendations by radiologists for clarification of MRA findings, as well as systems processes related to synchronous CTA/MRA order placement.

Traumatic Cervical Cerebrovascular Injury and the Role of CTA: AJR Expert Panel Narrative Review

Traumatic cerebrovascular injury (CVI) involving the cervical carotid and vertebral arteries is rare but can lead to stroke, hemodynamic compromise, and mortality in the absence of early diagnosis and treatment. The diagnosis of both blunt cerebrovascular injury (BCVI) and penetrating CVI is based on cerebrovascular imaging. The most commonly used screening criteria for BCVI include the expanded Denver criteria and the Memphis criteria, each providing varying thresholds for subsequent imaging. Neck CTA has supplanted catheter-based digital subtraction angiography as the preferred screening modality for CVI in patients with trauma. This AJR Expert Panel Narrative Review describes the current state of CTA-based cervical imaging in trauma. We review the most common screening criteria for BCVI, discuss BCVI grading scales that are based on neck CTA, describe the diagnostic performance of CTA in the context of other imaging modalities and evolving treatment strategies, and provide a practical guide for neck CTA implementation.

Rationale for issuing neuroimaging requests for patients with primary headaches in China

OBJECTIVE

To investigate the prevalence of neuroimaging in patients with primary headaches and the clinician-based rationale for requesting neuroimaging in China.

DATA SOURCES AND STUDY SETTING

This study included patients with primary headaches admitted to hospitals and clinicians in China. We identified whether neuroimaging was requested and the types of neuroimaging conducted.

STUDY DESIGN

This was a cross-sectional study, and convenience sampling was used to recruit patients with primary headaches. Clinicians were interviewed using a combination of personal in-depth and topic-selection group interviews to explore why doctors requested neuroimaging.

DATA COLLECTION

We searched for the diagnosis of primary headache in the outpatient and inpatient systems according to the International Classification of Diseases-10 code of patients admitted to six hospitals in three provincial capitals by 2022.We selected three public and three private hospitals with neurology specialties that treated a corresponding number of patients.

PRINCIPLE FINDINGS

Among the 2263 patients recruited for this study, 1942 (89.75%) underwent neuroimaging. Of the patients, 1157 (51.13%) underwent magnetic resonance imaging (MRI), 246 (10.87%) underwent both head computed tomography (CT) and MRI, and 628 (27.75%) underwent CT. Fifteen of the 16 interviewed clinicians did not issue a neuroimaging request for patients with primary headaches. Furthermore, we found that doctors issued a neuroimaging request for patients with primary headaches mostly, to exclude the risk of misdiagnosis, reduce uncertainty, avoid medical disputes, meet patients' medical needs, and complete hospital assessment indicators.

CONCLUSIONS

For primary headaches, the probability of clinicians requesting neuroimaging was higher in China than in other countries. There is considerable room for improvement in determining appropriate strategies to reduce the use of low-value care for doctors and patients.

Effect of Provider Type on Overutilization of CT Angiograms of the Head and Neck for Patients Presenting to the Emergency Department with Nonfocal Neurologic Symptoms

PURPOSE

Overutilization of neuroimaging in the emergency department (ED), especially CT angiogram of the head and neck (CTAHN) examinations, contributes to rising health care expenditures, exposes patients to radiation, and may result in delays in care. We evaluated the rate of CTAHN overutilization for patients with nonfocal neurologic complaints in the ED and its potential association with patient clinical data, demographic data, and ED provider type.

METHODS

This study was retrospective, was approved by an institutional review board, and was performed at a single institution, spanning a 6-year period. ED patients with nonfocal neurologic complaints who had a CTAHN examination with no history of trauma, recent surgery, or intracranial malignancy were included. Each CTAHN examination was categorized into one of four groups (0 = negative, 1 = chronic findings not related to presentation, 2 = nonacute and/or nonemergent findings or findings that may account for the presentation, and 3 = acute and/or emergent findings that may account for the presentation). Basic demographic data including patient age, patient sex, ordering ED provider type (attending, resident, nonphysician practitioner [(NPP]) were collected and analyzed using a multiple logistic regression analysis.

RESULTS

A total of 960 CTAHN examinations were reviewed. The mean age of patients was 50 years (SD = 18 years), with 63% female patients and 37% male patients. Headache was the most frequent presentation (76%). A total of 75% of cases were negative, and 7% had chronic imaging findings not related to their ED presentation. A total of 12.5% of cases had nonacute and/or nonemergent findings possibly related to the presentation, and only 5.5% had acute and/or emergent findings related to ED presentation. A significantly greater proportion of CTAHN examinations ordered by NPPs, followed by the proportion ordered by ED residents, were negative or had no findings related to the patient presentation, and these patients were ultimately discharged to home.

DISCUSSION

A total of 82% of ED CTAHN examinations performed for patients with nonfocal neurologic complaints had no actionable findings. These examinations are significantly more likely to be ordered by NPPs and ED residents.

Mechanical thrombectomy in patients with acute ischemic stroke in the USA before and after time window expansion

BACKGROUND

In 2018, the time window for mechanical thrombectomy eligibility in patients with acute ischemic stroke increased from within 6 hours to within 24 hours of symptom onset. The purpose of this study was to evaluate the effect of window expansion on procedural and hospital volumes and patient outcomes at a national level.

METHODS

We conducted a retrospective cohort study of patients with acute ischemic stroke undergoing mechanical thrombectomy using data from the National Inpatient Sample. We compared the numbers of mechanical thrombectomy procedures and performing hospitals between 2017 and 2019 in the USA, and the proportion of patients discharged home/self-care, those with in-hospital mortality and post-procedural intracranial hemorrhage (2019 vs 2017) after adjustment for potential confounders.

RESULTS

The number of patients with ischemic stroke who underwent mechanical thrombectomy increased from 16 960 in 2017 to 28 120 in 2019. There was an increase in the number of hospitals performing mechanical thrombectomy (501 in 2017, 585 in 2019) and those performing ≥50 procedures/year (97 in 2017, 199 in 2019; P<0.001). The odds of in-hospital mortality decreased (OR 0.79, 95% CI 0.66 to 0.94, P=0.008) and the odds of intracranial hemorrhage increased (OR 1.18, 95% CI 1.06 to 1.31, P=0.003) in 2019 compared with 2017, with no change in odds of discharge to home.

CONCLUSIONS

The window expansion for mechanical thrombectomy for patients with acute ischemic stroke was associated with an increase in the numbers of mechanical thrombectomy procedures and performing hospitals with a reduction of in-hospital mortality in the USA.

Shifts in Diagnostic Testing for Headache in the Emergency Department, 2015 to 2021

Importance

Subarachnoid hemorrhage is typically diagnosed by noncontrast head computed tomography (CT); lumbar puncture is recommended if computed tomography is nondiagnostic, although CT cerebral angiography has been promoted as an alternative to lumbar puncture in this diagnostic pathway. The outcomes of this debate in practice have not been studied.

Objective

To determine whether CT cerebral angiography use has increased in lieu of lumbar puncture among emergency department (ED) patients with headache, with an increase in unruptured intracranial aneurysm detection.

Design, Setting, and Participants

This retrospective cohort study took place in 21 community EDs of an integrated health care system in Northern California between 2015 and 2021. Participants were adult (aged >17 years) health plan members with a chief concern of headache. Exclusions were prior diagnoses of subarachnoid hemorrhage, unruptured intracranial aneurysm, cerebral arteriovenous malformation, or cerebrospinal fluid shunt. Data were analyzed from October to November 2023.

Exposures

CT cerebral angiography and/or lumbar puncture during the ED encounter.

Main Outcomes and Measures

Primary and secondary outcomes were 14-day and 90-day unruptured intracranial aneurysm detection, respectively. Safety outcomes were missed diagnoses of subarachnoid hemorrhage or bacterial meningitis. The annual incidence of unruptured intracranial aneurysm detection was normalized to the incidence of subarachnoid hemorrhage (UIA:SAH ratio). Average annualized percentage changes were quantified using joinpoint regression analysis.

Results

Among 198 109 included ED encounters, the mean (SD) age was 47.5 (18.4) years; 140 001 patients (70.7%) were female; 29 035 (14.7%) were Black or African American, 59 896 (30.2%) were Hispanic or Latino, and 75 602 (38.2%) were White. Per year, CT cerebral angiography use increased (18.8%; 95% CI, 17.7% to 20.3%) and lumbar punctures decreased (-11.1%; 95% CI, -12.0% to -10.4%), with a corresponding increase in the 14-day UIA:SAH ratio (3.5%; 95% CI, 0.9% to 7.4%). Overall, computed tomography cerebral angiography use increased 6-fold relative to lumbar puncture, with a 33% increase in the detection of UIA. Results were similar at 90 days and robust to sensitivity analyses. Subarachnoid hemorrhage (1004 cases) and bacterial meningitis (118 cases) were misdiagnosed in 5% and 18% of cases, respectively, with no annual trends (P = .34; z1003 = .95 and P = .74; z117 = -.34, respectively).

Conclusions and Relevance

In this cohort study of ED patients with headache, increases in CT cerebral angiography use were associated with fewer lumbar punctures and higher detection of unruptured intracranial aneurysms, with no significant change in missed diagnoses of subarachnoid hemorrhage or bacterial meningitis. While this shift in diagnostic strategy appeared safe in the short-term, the long-term consequences remain unclear.

Epidemiology of Spontaneous Cervical Artery Dissection: Population-Based Study

BACKGROUND

Cervical artery dissection (CeAD) represents up to 15% to 25% of ischemic strokes in people under the age of 50 years. Noninvasive vessel imaging is increasingly used in clinical practice, but the impact on the frequency of detection of CeAD is unknown. In 2006, the yearly incidence rate of CeAD was estimated at 2.6 per 100 000 person-years, but the current incidence is unknown.

METHODS

In this population-based retrospective observational cohort study, we utilized the resources of the Rochester Epidemiology Project to ascertain all adult residents of Olmsted County, MN, diagnosed with internal carotid artery dissection and common carotid artery dissection or vertebral artery dissection from 2002 to 2020. Patients with only intracranial involvement or CeAD following major trauma were excluded. Age-adjusted sex-specific and age- and sex-adjusted incidence rates were estimated using the US White 2010 decennial census, with rates expressed per 100 000 person-years. We assessed longitudinal trends by dividing the data into 5-year time intervals, with the last being a 4-year interval.

RESULTS

We identified 123 patients with a diagnosis of CeAD. There were 63 patients with internal carotid artery dissection, 54 with vertebral artery dissection, 2 with concurrent internal carotid artery dissection and vertebral artery dissection, and 4 with common carotid artery dissection. There were 63 (51.2%) female patients and 60 (48.8%) male patients. The average age at diagnosis was 50.2 years (SD, 15.1 [95% CI, 20.1-90.5] years). The incidence rate of spontaneous CeAD encompassing all locations was 4.69 per 100 000 person-years (2.43 for internal carotid artery dissection and 2.01 for vertebral artery dissection). The incidence rate increased from 2.30 per 100 000 person-years from 2002 to 2006 to 8.93 per 100 000 person-years from 2017 to 2020 (P<0.0001). The incidence rate for female patients rose from 0.81 per 100 000 person-years from 2002 to 2006 to 10.17 per 100 000 person-years from 2017 to 2020.

CONCLUSIONS

The incidence rate of spontaneous CeAD increased nearly 4-fold over a 19-year period from 2002 to 2020. The incidence rate in women rose over 12-fold. The increase in incidence rates likely reflects the increased use of noninvasive vascular imaging.

Detection Rates and Trends of Asymptomatic Unruptured Intracranial Aneurysms From 2005 to 2019

BACKGROUND AND OBJECTIVES

The trend in detection rates of asymptomatic unruptured intracranial aneurysms (UIAs) on brain computed tomography angiography/magnetic resonance angiography (CTA/MRA) is not well established. Our objective was to evaluate time trends in asymptomatic UIA detection rates on brain CTA/MRA between 2005 and 2019.

METHODS

We conducted a retrospective study of all brain computed tomography/magnetic resonance scans (n = 288 336 scans in 130 621 patients) performed between January 2005 and December 2019 at a tertiary referral hospital. Patients who underwent brain CTA/MRA examinations were included (n = 81 261 scans in 48 037 patients). The annual detection rate of new UIA cases was calculated based on the first brain CTA/MRA imaging. Detection rates were compared between three periods and across different age groups.

RESULTS

The number of first CTA/MRA examinations increased significantly from 2005 to 2009 (n = 12 190 patients) to 2010-2014 (n = 14 969 patients) and 2015-2019 (n = 20 878 patients) ( P < .001). The UIA detection rate also increased significantly from 1.7% in 2005-2009 to 2.5% in 2010-2014 and 3.4% in 2015-2019 ( P < .001). The UIA detection rate increased significantly from 2010-2014 to 2015-2019 (relative risk [RR], 1.33; 95% CI, 1.17-1.51), particularly in patients aged 60-69 years (RR, 1.29; 95% CI, 1.01-1.63), 70-79 years (RR, 1.71; 95% CI, 1.30-2.25), and >79 years (RR, 2.33; 95% CI, 1.56-3.47). Furthermore, the detection rate of <5-mm UIAs increased from 2010-2014 to 2015-2019 (RR, 1.51; 95% CI, 1.28-1.77).

CONCLUSION

The detection rate of asymptomatic UIAs, particularly in elderly patients, has increased significantly over the past 15 years, coinciding with the increased use of CTA/MRA imaging. Furthermore, the size of the identified UIAs has decreased. These findings raise concerns about the management strategies for UIAs, indicating the need for further research.

Cost-Effectiveness of CT, CTA, MRI, and Specialized MRI for Evaluation of Patients Presenting to the Emergency Department With Dizziness

BACKGROUND. Underlying stroke is often misdiagnosed in patients presenting with dizziness. Although such patients are usually ineligible for acute stroke treatment, accurate diagnosis may still improve outcomes through selection of patients for secondary prevention measures. OBJECTIVE. The purpose of our study was to investigate the cost-effectiveness of differing neuroimaging approaches in the evaluation of patients presenting to the emergency department (ED) with dizziness who are not candidates for acute intervention. METHODS. A Markov decision-analytic model was constructed from a health care system perspective for the evaluation of a patient presenting to the ED with dizziness. Four diagnostic strategies were compared: noncontrast head CT, head and neck CTA, conventional brain MRI, and specialized brain MRI (including multiplanar high-resolution DWI). Differing long-term costs and outcomes related to stroke detection and secondary prevention measures were compared. Cost-effectiveness was calculated in terms of lifetime expenditures in 2022 U.S. dollars for each quality-adjusted life year (QALY); deterministic and probabilistic sensitivity analyses were performed. RESULTS. Specialized MRI resulted in the highest QALYs and was the most cost-effective strategy with US$13,477 greater cost and 0.48 greater QALYs compared with noncontrast head CT. Conventional MRI had the next-highest health benefit, although was dominated by extension with incremental cost of US$6757 and 0.25 QALY; CTA was also dominated by extension, with incremental cost of US$3952 for 0.13 QALY. Non-contrast CT alone had the lowest utility among the four imaging choices. In the deterministic sensitivity analyses, specialized MRI remained the most cost-effective strategy. Conventional MRI was more cost-effective than CTA across a wide range of model parameters, with incremental cost-effectiveness remaining less than US$30,000/QALY. Probabilistic sensitivity analysis yielded similar results as found in the base-case analysis, with specialized MRI being more cost-effective than conventional MRI, which in turn was more cost-effective than CTA. CONCLUSION. The use of MRI in patients presenting to the ED with dizziness improves stroke detection and selection for subsequent preventive measures. MRI-based evaluation leads to lower long-term costs and higher cumulative QALYs. CLINICAL IMPACT. MRI, incorporating specialized protocols when available, is the preferred approach for evaluation of patients presenting to the ED with dizziness, to establish a stroke diagnosis and to select patients for secondary prevention measures.

CASMatching strategy for automated detection and quantification of carotid artery stenosis based on digital subtraction angiography

BACKGROUND AND OBJECTIVE

Automated detection and quantification of carotid artery stenosis is a crucial task in establishing a computer-aided diagnostic system for brain diseases. Digital subtraction angiography (DSA) is known as the "gold standard" for carotid stenosis diagnosis. It is commonly used to identify carotid artery stenosis and measure morphological indices of the stenosis. However, using deep learning to detect stenosis based on DSA images and further quantitatively predicting the morphological indices remain a challenge due the absence of prior work. In this paper, we propose a quantitative method for predicting morphological indices of carotid stenosis.

METHODS

Our method adopts a two-stage pipeline, first locating regions suitable for predicting morphological indices by object detection model, and then using a regression model to predict indices. A novel Carotid Artery Stenosis Matching (CASMatching) strategy is introduced into the object detection to model the matching relationship between a stenosis and multiple normal vessel segments. The proposed Match-ness branch predicts a Match-ness score for each normal vessel segment to indicate the degree of matching to the stenosis. A novel Direction Distance-IoU (2DIoU) loss based on the Distance-IoU loss is proposed to make the model focused more on the bounding box regression in the direction of vessel extension. After detection, the normal vessel segment with the highest Match-ness score and the stenosis are intercepted from the original image, then fed into a regression model to predict morphological indices and calculate the degree of stenosis.

RESULTS

Our method is trained and evaluated on a dataset collected from three different manufacturers' monoplane X-ray systems. The results show that the proposed components in the object detector substantially improve the detection performance of normal vascular segments. For the prediction of morphological indices, our model achieves Mean Absolute Error of 0.378, 0.221, 4.9 on reference vessel diameter (RVD), minimum lumen diameter (MLD) and stenosis degree.

CONCLUSIONS

Our method can precisely localize the carotid stenosis and the normal vessel segment suitable for predicting RVD of the stenosis, and further achieve accurate quantification, providing a novel solution for the quantification of carotid artery stenosis.

Pearls and pitfalls in emergency CT neuroangiography through the lens of bias and error

Computed tomography angiography (CTA) of the head and neck is central in emergency department (ED) evaluation of clinically suspected acute stroke and intracranial hemorrhage. Timely and accurate detection of acute findings is crucial for best clinical outcomes; missed or delayed diagnosis can be devastating. Our pictorial essay presents twelve CTA cases that provided significant diagnostic dilemmas to on-call trainees while reviewing current bias and error classifications in radiology. Among others, we discuss anchoring, automation, framing, satisfaction of search, scout neglect and zebra-retreat bias. Each imaging vignette depicts a potential diagnostic "pitfall" while introducing types of cognitive bias/error before concluding with a concrete "pearl" for CTA interpretation. We believe that familiarity with bias and error is particularly important in the ED setting where high case volume, high acuity and radiologist fatigue intersect. Particular attention to personal cognitive biases and these potential CTA pitfalls may help emergency radiologists transition from habit-driven pattern recognition to analytical thinking, ultimately improving diagnostic decision making.

Major radiological outcomes of CTA head and neck performed for dizziness in a major academic Emergency Department

Purpose: Routine head and neck CTAs (CTAhead+neck) performed for dizziness in the Emergency Department (ED) has steadily increased, but its clinical utility is still poorly elucidated. Our purpose was to assess the radiologic outcomes of CTAhead+neck in ED dizziness patients.Methods: ED dizziness patients with CTAhead+neck from January 2010 through November 2019 were retrospectively identified and further stratified into central vertigo (CV), peripheral vertigo (PV), and non-specific dizziness (NSD) groups by final clinical diagnoses. Findings on CTAhead+neck (vessel stenosis >50%, occlusion, dissection, and infarct), and infarct on subsequent MRI if performed, were assessed. Differences in imaging findings were analyzed using chi-square or Fisher's exact tests.Results: Of 867 dizziness patients, 88 were diagnosed with CV, 383 with PV, and 396 with NSD. On CTAhead+neck, 11.4% of all patients had posterior CTA findings, including posterior occlusions (4.2%), dissections (1.2%), and infarcts (2.3%). CV patients had more posterior circulation findings (31.8%) versus PV (9.9%) and NSD (8.3%) patients (both p < 0.01). 21.6% of CV patients had acute infarcts on CT versus none for PV and 0.03% for NSD patients (both p < 0.01). On MRI, 46.6% of CV patients had acute posterior circulation infarcts versus none for PV and 0.3% for NSD patients (p < 0.01).Conclusion: Diagnostic yield for CTAhead+neck for dizziness patients is low except in central vertigo patients which constitute only 1/10th of CTAs performed. Our single institution results support that CTAhead+neck is likely low-yield in patients with high clinical suspicion for PV or NSD and further studies are needed to test this hypothesis.

An ultrafast brain MRI technique for evaluating acute neurologic deficits in the emergency department

Herein we share our preliminary experience with an ultrafast brain MRI technique for use in the ED consisting of axial T1-weighted (40 s), axial T2-weighted (62 s), axial diffusion-weighted (80 s), axial FLAIR (96 s), axial T2* (6 s), and axial susceptibility-weighted (108 s) imaging for a total scan time of 6 min and 53 s. Utilization of this ultrafast technique yields an efficient assessment of the brain, decreases ED length of stay and inpatient observation admissions, and may obviate the need for vascular imaging with either CTA or MRA in the ED.

Deep learning image reconstruction algorithm for carotid dual-energy computed tomography angiography: evaluation of image quality and diagnostic performance

Objectives

To evaluate image quality and diagnostic performance of carotid dual-energy computed tomography angiography (DECTA) using deep learning image reconstruction (DLIR) compared with images using adaptive statistical iterative reconstruction-Veo (ASIR-V).

Methods

Carotid DECTA datasets of 28 consecutive patients were reconstructed at 50 keV using DLIR at low, medium, and high levels (DLIR-L, DLIR-M, and DLIR-H) and 80% ASIR-V algorithms. Mean attenuation, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) at different levels of arteries were measured and calculated. Image quality for noise and texture, depiction of arteries, and diagnostic performance toward carotid plaques were assessed subjectively by two radiologists. Quantitative and qualitative parameters were compared between the ASIR-V, DLIR-L, DLIR-M, and DLIR-H groups.

Results

The image noise at aorta and common carotid artery, SNR, and CNR at all level arteries of DLIR-H images were significantly higher than those of ASIR-V images (p = 0.000–0.040). The quantitative analysis of DLIR-L and DLIR-M showed comparable denoise capability with ASIR-V. The overall image quality (p = 0.000) and image noise (p = 0.000–0.014) were significantly better in the DLIR-M and DLIR-H images. The image texture was improved by DLR at all level compared to ASIR-V images (p = 0.000–0.008). Depictions of head and neck arteries and diagnostic performance were comparable between four groups (p > 0.05).

Conclusions

Compared with 80% ASIR-V, we recommend DLIR-H for clinical carotid DECTA reconstruction, which can significantly improve the image quality of carotid DECTA at 50 keV but maintain a desirable diagnostic performance and arterial depiction.

Interrelationship Between Craniocervical Dissociation Spectrum Injuries and Atlantoaxial Instability on Trauma Cervical MRI Examinations

Background and purpose Craniocervical dissociation injuries encompass a spectrum of osteoligamentous injuries between the skull base and C1-C2 that may be treated via prolonged external immobilization versus occipital cervical fusion depending on the risk of persistent craniocervical instability. However, the presence of atlantoaxial instability (AAI) at C1-C2, as determined by transverse atlantal ligament (TAL) integrity with or without a C1 fracture, may guide the neurosurgical management of craniocervical dissociation spectrum injuries (CDSI) since it implies an overall greater degree of instability at the craniocervical junction (CCJ). Materials and methods Adult trauma patients who suffered a transverse atlantal ligament injury on cervical magnetic resonance imaging (MRI) were identified retrospectively. The cervical computed tomography (CT) and magnetic resonance imaging examinations for these patients were reviewed for additional traumatic findings. Demographic information, treatment, and outcome information were recorded. Results Twenty-nine trauma patients presented to the emergency department (ED) with an acute, midsubstance transverse atlantal ligament tear on cervical magnetic resonance imaging. Thirty-one percent of patients demonstrated a tear in at least one major craniocervical ligament (atlanto-occipital capsular ligaments, alar ligaments, and tectorial membrane {TM}) with 14% demonstrating a tear in two major craniocervical ligaments and no patients demonstrating a tear in all three major craniocervical ligaments. Minor craniocervical ligament injuries (anterior atlanto-occipital membrane complex {AAOMc} and posterior atlanto-occipital membrane complex {PAOMc}) were common and observed in 76% of patients. Conclusions Our study suggests that multiple major craniocervical junction ligamentous injuries on cervical magnetic resonance imaging are relatively uncommon in the setting of transverse atlantal ligament injury.

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.

Head and Neck CTA Utilization: Analysis of Ordering Frequency and Nonroutine Results Communication, With Focus on the Fifty Most Common Emergency Department Clinical Presentations

Background: Utilization of head and neck CTA in the emergency department (ED) has grown disproportionately to other neuroimaging examinations. Objective: To characterize utilization of head and neck CTA in the ED, comparing utilization and frequency of nonroutine results communication among patients' chief concerns. Methods: All adult ED visits for a single healthcare system from January 2014 to December 2017 were retrospectively reviewed. Variables recorded included chief concerns, whether head and neck CTA was performed, and, if so, whether the report documented nonroutine results communication. The fifty chief concerns resulting in the highest number of head and neck CTA examinations were identified. Frequencies of head and neck CTA ordering and of nonroutine results communication were calculated. A subset of reports documenting nonroutine communication were manually reviewed. Results: Head and neck CTA was ordered in 2.5% (17,903) of 708,145 ED visits in 236,476 patients (mean age 48.9±20.5 years; 110,952 male, 125,521 female, 3 unknown sex). Head and neck CTA was ordered for 833 distinct chief concerns. Nonroutine results communication was documented for 17.6% (31,55/17,903) of examinations. Among the fifty chief concerns associated with the highest number of examinations, frequency of ordering head and neck CTA ranged from <0.5% (five concerns) to 55.2% (stroke code), and frequency of nonroutine communication ranged from 5.6% (transient ischemic attack) to 67.5% (unresponsive). Chief concerns not among the fifty most common accounted for 50.0% (8956/17903) of examinations; these exhibited a collective frequency of nonroutine communication of 4.8% (429/8956). Manual review of 11.1% (350/3155) of reports with a nonroutine communication indicated an acute finding related to the indication in 51.1%, non-emergent but potentially explanatory finding in 28.0%, incidental finding in 28.0%, and communication of negative results in 6.9%. Conclusion: Head and neck CTA is ordered in 2.5% of ED visits for a wide range of chief concerns. Frequencies of ordering and of nonroutine results communication are highly variable among chief concerns. Acute indication-related findings account for half of nonroutine radiologist communications. Clinical Impact: Insight into patterns regarding head and neck CTA ordering and nonroutine results may help optimize patient selection and radiologist communications in the ED setting.