Non-contrast Head CT Scan Research Articles

“Worst Headache of Life” in a Migraineur: Marginal Value of Emergency Department CT Scanning

PurposeThe ACR Appropriateness Criteria recommend performing noncontrast head CT (NCCT) for patients with sudden severe headache (“worst headache of life” [WHOL] or “thunderclap headache” [TCH]). The aim of this study was to assess the value of NCCT scanning in patients with known migraine histories and WHOL or TCH. The hypothesis was that there would be little utility in performing emergency department (ED) NCCT scans in migraineurs without other red flags, even if they had WHOL or TCH. MethodsThe ED NCCT scans of all patients reporting WHOL or TCH who had established diagnoses of migraine were retrospectively reviewed over a 5-year period. Patients without known intracranial pathology, cancer, or immunocompromising disease or recent head trauma were included as the main study group. For comparison, patients with any of those factors were included as the comparison group. Scans were graded as (1) normal, (2) minor unimportant findings, (3) findings requiring intervention or follow-up, or (4) critical. ResultsTwo hundred twenty-four patients with the chief symptom of WHOL or TCH and a history of migraine who underwent ED NCCT were studied. In the main study group, no patients had grade 4 imaging findings (0%), one had a false-positive grade 3 finding (0.8%), and there were no cases of subarachnoid hemorrhage (0%). In the comparison group, six patients had grade 4 imaging findings (6.5%) and three had grade 3 findings (3.3%). ConclusionsNCCT in known migraineurs with WHOL or TCH who do not have intracranial pathology, cancer, immunocompromising disease, or recent head trauma yielded no critical findings. Therefore, the value of scanning these patients is questionable.

Prescreening for Intracranial Hemorrhage on CT Head Scans with an AI-Based Radiology Workflow Triage Tool: An Accuracy Study

Purpose: To evaluate a recently FDA-approved AI-based radiology workflow triage device for accuracy in identification of intracranial hemorrhage (ICH) on prescreening of real-world CT brain scans. Method/Materials: An AI-based device ("the algorithm") for ICH detection on CT brain scans was studied at our institution; the algorithm was developed by outside company Aidoc (Tel Aviv, Israel). A retrospective dataset of 533 non-contrast head CT scans was collected from our large urban tertiary academic medical center. Following convention for studies evaluating sensitivities and specificities of imaging computer-aided detection and diagnosis devices, a prevalence-enriched dataset was utilized such that a 50% prevalence of intracranial hemorrhage was obtained. The algorithm was run on the dataset. Cases flagged by the algorithm as positive for ICH were defined as “positive”, and the rest as “negative”. The results were compared to the ground truth, determined by neuroradiologist review of the dataset. Sensitivity and specificity were calculated. Additionally, Negative-Predictive-Value (NPV) and Positive-Predictive-Value (PPV) calculations were made from the prevalence-enriched study data, which enable lower and upper threshold estimates for real-world NPV and PPV, respectively. Metrics were analyzed using a two-sided, exact binomial, 95% confidence-interval. Results: Algorithm sensitivity was 96.2% (CI: 93.2%-98.2%); specificity was 93.3% (CI: 89.6-96.0%). Estimated realworld NPV was determined as at least 96.2% (CI: 93.2%-97.9%), and an estimated upper threshold for PPV was estimated as 93.4% (CI: 90.1%-95.7%). Conclusion: The tested device detects intracranial hemorrhage with high sensitivity and specificity. These findings support the potential utility of using the device to autonomously surveil radiology worklists for studies containing critical findings, triage a busy workflow and ultimately improve patient care in clinically time-sensitive cases.

Deep learning algorithms for detection of critical findings in head CT scans: a retrospective study

Non-contrast head CT scan is the current standard for initial imaging of patients with head trauma or stroke symptoms. We aimed to develop and validate a set of deep learning algorithms for automated detection of the following key findings from these scans: intracranial haemorrhage and its types (ie, intraparenchymal, intraventricular, subdural, extradural, and subarachnoid); calvarial fractures; midline shift; and mass effect. We retrospectively collected a dataset containing 313 318 head CT scans together with their clinical reports from around 20 centres in India between Jan 1, 2011, and June 1, 2017. A randomly selected part of this dataset (Qure25k dataset) was used for validation and the rest was used to develop algorithms. An additional validation dataset (CQ500 dataset) was collected in two batches from centres that were different from those used for the development and Qure25k datasets. We excluded postoperative scans and scans of patients younger than 7 years. The original clinical radiology report and consensus of three independent radiologists were considered as gold standard for the Qure25k and CQ500 datasets, respectively. Areas under the receiver operating characteristic curves (AUCs) were primarily used to assess the algorithms. The Qure25k dataset contained 21 095 scans (mean age 43 years; 9030 [43%] female patients), and the CQ500 dataset consisted of 214 scans in the first batch (mean age 43 years; 94 [44%] female patients) and 277 scans in the second batch (mean age 52 years; 84 [30%] female patients). On the Qure25k dataset, the algorithms achieved an AUC of 0·92 (95% CI 0·91-0·93) for detecting intracranial haemorrhage (0·90 [0·89-0·91] for intraparenchymal, 0·96 [0·94-0·97] for intraventricular, 0·92 [0·90-0·93] for subdural, 0·93 [0·91-0·95] for extradural, and 0·90 [0·89-0·92] for subarachnoid). On the CQ500 dataset, AUC was 0·94 (0·92-0·97) for intracranial haemorrhage (0·95 [0·93-0·98], 0·93 [0·87-1·00], 0·95 [0·91-0·99], 0·97 [0·91-1·00], and 0·96 [0·92-0·99], respectively). AUCs on the Qure25k dataset were 0·92 (0·91-0·94) for calvarial fractures, 0·93 (0·91-0·94) for midline shift, and 0·86 (0·85-0·87) for mass effect, while AUCs on the CQ500 dataset were 0·96 (0·92-1·00), 0·97 (0·94-1·00), and 0·92 (0·89-0·95), respectively. Our results show that deep learning algorithms can accurately identify head CT scan abnormalities requiring urgent attention, opening up the possibility to use these algorithms to automate the triage process. Qure.ai.

Clinical utility and cost analysis of routine postoperative head CT in elective aneurysm clippings.

OBJECTIVE Postoperative head CT scanning is performed routinely at the authors' institution on all neurosurgical patients after elective aneurysm clippings. The goal of this study was to determine how often these scans influence medical management and to quantify the associated imaging costs. METHODS The authors reviewed the medical records and accounting database of 304 patients who underwent elective (i.e., nonruptured) aneurysm clipping performed by 1 surgeon (M.T.L.) from 2010 to 2014 at the University of California, San Francisco. Specifically, the total number of postoperative head CT scans, radiographic findings, and the effect of these studies on patient management were determined. The authors obtained the total hospital costs for these patients, including the cost of imaging studies, from the hospital accounting database. RESULTS Overall, postoperative CT findings influenced clinical management in 3.6% of cases; specifically, they led to permissive hypertension in 4 patients for possible ischemia, administration of mannitol for edema and high-flow oxygen for pneumocephalus in 2 patients each, seizure prophylaxis in 1 patient, Plavix readjustment in 1 patient, and return to the operating room for an asymptomatic epidural hematoma evacuation in 1 patient. When patients were stratified on the basis of postoperative neurological examination, findings on CT scans altered management in 1.1%, 4.8%, and 9.0% of patients with no new neurological deficits, a nonfocal examination, and focal deficits, respectively. The mean total hospital cost for treating patients who undergo elective aneurysm clipping was $72,227 (± $53,966) (all values are US dollars), and the cost of obtaining a noncontrast head CT scan was $292. Neurologically intact patients required 99 head CT scans, at a cost of $28,908, to obtain 1 head CT scan that influenced medical management. In contrast, patients with a focal neurological deficit required only 11 head CT scans, at a cost of $3212, to obtain 1 head CT scan that changed clinical management. CONCLUSIONS Although there are no clear guidelines, the large number and high cost of CT scans needed to treat neurologically intact elective aneurysm patients suggest that careful neurological monitoring may be more clinically useful and a better use of hospital resources than routine postoperative CT.

Evaluation of the use of automatic exposure control and automatic tube potential selection in low-dose cerebrospinal fluid shunt head CT.

Cerebrospinal fluid shunts are primarily used for the treatment of hydrocephalus. Shunt complications may necessitate multiple non-contrast head CT scans resulting in potentially high levels of radiation dose starting at an early age. A new head CT protocol using automatic exposure control and automated tube potential selection has been implemented at our institution to reduce radiation exposure. The purpose of this study was to evaluate the reduction in radiation dose achieved by this protocol compared with a protocol with fixed parameters. A retrospective sample of 60 non-contrast head CT scans assessing for cerebrospinal fluid shunt malfunction was identified, 30 of which were performed with each protocol. The radiation doses of the two protocols were compared using the volume CT dose index and dose length product. The diagnostic acceptability and quality of each scan were evaluated by three independent readers. The new protocol lowered the average volume CT dose index from 15.2 to 9.2mGy representing a 39% reduction (P < 0.01; 95% CI 35-44%) and lowered the dose length product from 259.5 to 151.2mGy/cm representing a 42% reduction (P < 0.01; 95% CI 34-50%). The new protocol produced diagnostically acceptable scans with comparable image quality to the fixed parameter protocol. A pediatric shunt non-contrast head CT protocol using automatic exposure control and automated tube potential selection reduced patient radiation dose compared with a fixed parameter protocol while producing diagnostic images of comparable quality.

Utility of intraoperative diagnostic C-arm angiography for management of high grade subarachnoid hemorrhage

Abstract The accurate and efficient localization of underlying vascular lesions is crucial for prompt and definitive treatment of subarachnoid hemorrhage (SAH). To demonstrate the utility and feasibility of intraoperative C-arm angiography in cerebrovascular emergencies, we report five cases of high grade SAH and/or intracerebral hemorrhage (ICH) where intraoperative diagnostic C-arm angiography was safely and effectively utilized. Initial evaluations of all patients included a non-contrast head CT scan, which was followed by urgent decompressive hemicraniectomy as a life-saving measure in the presence of markedly elevated intracranial pressure. Further diagnostic evaluations were performed intraoperatively using a multi-purpose C-arm angiography system. The C-arm angiography findings greatly aided the intraoperative planning and led to definitive treatments in four cases of SAH by elucidating the underlying neurovascular lesions. With this treatment strategy, two of the patients made moderately good recoveries from their SAH and/or ICH with a Glasgow outcome score (GOS) of 4. Three of the patients expired despite maximal therapy mostly due to unfavorable presenting grade. These results suggest that C-arm angiography is a reasonable diagnostic and surgical planning tool for selected patients with high grade diffuse SAH who require immediate decompression.

The runny nose

A 40-year-old woman presented with a ‘‘runny nose’’ of 3 month’s duration. Every morning, she had a gush of watery discharge from her nose. There was no history of headache, fever, head trauma, or neurosurgical procedure, and the patient did not use any medication. She had no coryza or sinusitis symptoms. On physical examination, the patient was alert with normal vital signs. There was a continuous fluid leakage from the right nostril. The examination was otherwise normal including neurologic examination. Laboratory studies including CBC and a complete metabolic panel were within normal limits. Computed tomography (CT scan) of her head was performed. It showed no parenchymal abnormality. There was an air-fluid level (Panel A and B) and a small suspected bony defect in the lateral wall of the right sphenoid sinus (Panel A-arrow) (Fig. 1). Since an air-fluid level in the sphenoid sinus is always abnormal, in the absence of sinusitis symptoms, head trauma, or previous neurosurgical procedures, it connotes a fluid, namely cerebrospinal fluid (CSF). With the impression of a CSF leak, the watery gush in the mornings was attributed to accumulation of CSF in her sphenoid sinus during the night, and sudden discharge by positional change of the head and the effect of gravity. A test for beta-2 transferrin was ordered, which was positive. Thus, a diagnosis of primary spontaneous cerebrospinal fluid rhinorrhea was made. CSF rhinorrhea refers to the drainage of CSF through a skull base defect into the nose. It can be spontaneous, or secondary to trauma, surgical procedures, or tumor. In order to make the diagnosis in the cases of bloody discharge, (which was not present in this case), filter paper to show a double ring sign can be used. A few drops of fluid from a CSF leak placed on absorbent filter paper will show a central circle of blood and an outer clear ring of CSF. Beta-2 transferrin measurement of the leaking fluid has a high specificity for detecting CSF, [1] and the non-contrast head CT scan is the imaging modality of choice [2]. While the exact etiology is unknown, there have been a number of theories postulated: such as embryologic development defect or aberrant arachnoid granulations. The most common sites of skull base leaks are at the floor of the anterior cranial fossa and sphenoid sinus, the cribriform plate being the thinnest bone wall of the area [3]. The risk factors include body mass index higher than 30, female gender, middle age, and low bone density (particularly evidence of osteoporosis) [3]. This condition may have devastating complications in some patients such as CNS infections, decreased intracranial pressure, and brain herniation. Management includes watchful waiting: (bed-rest, head elevation, and avoidance of straining), since leaks often stop spontaneously; if this does not occur then neurosurgical closure is necessary to prevent the onset of infection in the meninges. Hydroxyapatite cement was applied transnasally to the sphenoid region fistula, and the patient recovered uneventfully. Y. Daneshbod Department of Molecular Pathology, Dr Daneshbod Laboratory, Shiraz, Iran

Abstract T P261: Non-Contrast Head CT Prior to Comprehensive Neurological Evaluation Reduces Door to Needle Times for Administration of Intravenous rtPA

Background: American Heart Association/American Stroke Association recommends treatment of eligible acute ischemic stroke patients with intravenous rtPA &lt;60 minutes from emergency department arrival. Purpose: A quality improvement project was designed to reduce the door to needle times for intravenous rtPA administration at Mayo Clinic Florida. We hypothesized that workflow changes in emergency department evaluation of suspected stroke patients would decrease door to needle times. The goal was to treat &gt;75% of patients eligible for IV t-PA within 60 minutes of ED arrival. Methods: We utilized LEAN methods to develop a project charter, identify stakeholders, and visually map the emergency department clinical workflow. Prior to project initiation, suspected stroke patients were taken upon arrival to an exam room for clinical evaluation followed by transport to the CT scanner and return to the exam room for decision-making and rtPA administration. The clinical workflow was changed to obtain patient weight immediately upon arrival, abbreviated patient assessment and lab draws outside of the CT scanner in a holding bay and performing CT scanning prior to transport to an examination room for decision making and rtPA administration. Results: In a 12 month period preceding project initiation, 29 patients were treated with rtPA, 55 % were treated &lt;60 minutes of emergency department arrival. In the 11 month period following implementation of CT scanning prior to neurological evaluation, 57 patients were treated with rtPA, 80 % were treated in &lt;60 minutes of emergency department arrival. The mean door to needle time was reduced from 66 minutes to 46 minutes following the clinical workflow change. No patients experienced clinical deterioration at the time of CT scanning. Conclusions: Non-contrast head CT scan be safely performed prior to comprehensive neurological evaluation and reduces door-to-needle times for intravenous rtPA administration in eligible stroke patients. Validated process improvement paradigms such as LEAN have the potential to reduce door to needle times and improve patient outcomes.

Subcutaneous nodules in a child on long-term dialysis: Questions

A 15-year-old Saudi Arabian boy presented with painless hard subcutaneous swellings inhis fingerswith intact overlying skin (Fig. 1a). These lesions had developed over severalmonths.He had widespread bone pain and was unable to walk for 1 year. He presented in end-stage kidney disease (ESKD) of unknown etiology at 1 year of age and received peritoneal dialysis for 3 years. Due to repeated episodes of peritonitis, Fig. 1 a X-rays of both hands. b X-ray of left hip. c Non-contrast head CT scan

Sphenoid and Subdural Hemorrhage as a Presenting Sign of Ruptured Clinoid Aneurysm

Aneurysm rupture presenting as an isolated or pure subdural hematoma (SDH) without subarachnoid hemorrhage is an extremely rare radiographic presentation. We present a case of a ruptured internal carotid artery aneurysm with a pure SDH and concurrent sphenoid sinus hemorrhage. Case report and review of the literature. We describe a case of a 48-year-old right-handed woman found comatose brought by emergency medical services to an outside hospital. A non-contrast head CT scan demonstrated bilateral acute SDHs without evidence of intraparenchymal or subarachnoid hemorrhage. A CT angiogram of the head showed a focal hyperdensity in the distal left internal carotid artery (ICA) and was confirmed by conventional cerebral angiography to be a 7-mm left supraclinoid ICA aneurysm. On repeat CT scan a new hemorrhage was seen in the sphenoid sinus indicating a re-bleeding. The aneurysm was treated with coil embolization and complete occlusion was confirmed with subsequent angiograms. The patient had an eventful hospital course complicated by a Takotsubo cardiomyopathy and pulmonary edema. She was medically treated with successful recovery of her cardiopulmonary function. She remained markedly disabled and was transferred to an inpatient rehabilitation center for continued convalescence. Acute subdural hematoma may be due to a ruptured clinoid carotid aneurysm. Acute hemorrhage into the sphenoid sinus can be an important clue.

State of Emergency Medicine in Switzerland: a national profile of emergency departments in 2006

BackgroundEmergency departments (EDs) are an essential component of any developed health care system. There is, however, no national description of EDs in Switzerland. Our objective was to establish the number and location of EDs, patient visits and flow, medical staff and organization, and capabilities in 2006, as a benchmark before emergency medicine became a subspecialty in Switzerland.MethodsIn 2007, we started to create an inventory of all hospital-based EDs with a preliminary list from the Swiss Society of Emergency and Rescue Medicine that was improved with input from ED physicians nationwide. EDs were eligible if they offered acute care 24 h per day, 7 days per week. Our goal was to have 2006 data from at least 80% of all EDs. The survey was initiated in 2007 and the 80% threshold reached in 2012.ResultsIn 2006, Switzerland had a total of 138 hospital-based EDs. The number of ED visits was 1.475 million visits or 20 visits per 100 inhabitants. The median number of visits was 8,806 per year; 25% of EDs admitted 5,000 patients or less, 31% 5,001-10,000 patients, 26% 10,001-20,000 patients, and 17% >20,000 patients per year. Crowding was reported by 84% of EDs with >20,000 visits/year. Residents with limited experience provided care for 77% of visits. Imaging was not immediately available for all patients: standard X-ray within 15 min (70%), non-contrast head CT scan within 15 min (38%), and focused sonography for trauma (70%); 67% of EDs had an intensive care unit within the hospital, and 87% had an operating room always available.ConclusionsSwiss EDs were significant providers of health care in 2006. Crowding, physicians with limited experience, and the heterogeneity of emergency care capabilities were likely threats to the ubiquitous and consistent delivery of quality emergency care, particularly for time-sensitive conditions. Our survey establishes a benchmark to better understand future improvements in Swiss emergency care.

Proof of Concept Study: Relating Infarct Location to Stroke Disability in the NINDS rt-PA Trial

Background: The summed Alberta Stroke Program Early CT Score (ASPECTS) for noncontrast head CT scan represents the extent of early brain ischemia and has been shown to be useful for predicting stroke outcome. The ASPECTS template contains information on anatomical location which so far has not been used in analysis. This may not have been done because adjacent brain regions have related functions and share vascular territory. The task of relating neurological deficit to infarct localization requires brain imaging analysis tools which deal with this issue of relatedness or collinearity. We have previously used partial least squares with penalized logistic regression (PLR) to handle this problem of collinearity. A disadvantage of this method is that it cannot be performed at the bedside and requires processing and analysis in the imaging laboratory. PLR is a simpler analytic tool compared to partial least squares with PLR for dealing with this issue of relatedness (collinearity). It provides results in terms of β coefficients related to specific infarct locations in a manner that is intuitively understood by clinicians. In this exploratory analysis, we hypothesized that infarct location as represented by the individual ASPECTS region may be independently related to disability. Methods: ASPECTS from CT scans of patients in the National Institute of Neurological Disorders and Stroke (NINDS) recombinant tissue plasminogen activator (rt-PA) Study were obtained. Due to the collinearity between the ASPECTS regions, we used PLR to determine the independent associations of exposures (rt-PA), demographic variables (age and sex), and imaging (ASPECTS location) with poor outcome as defined by a modified Rankin Scale score of >2. Results: In 607/624 subjects with ASPECTS readings, variables significantly associated with poor outcome included: interactions between ASPECTS M6 region (primary motor cortex/parietal lobe) and age (p = 0.004), lentiform nucleus and age (p = 0.007), and blood sugar level and age (p = 0.01). The model suggested that older age or involvement of either M6 or lentiform nucleus slightly increased the odds of disability. However, the predominant effect was driven by rt-PA which reduced the odds of poor disability (OR 0.597, 95% CI 0.425-0.838, p = 0.003). This may potentially explain why certain patients have smaller gains from rt-PA treatments. Conclusion: At an older age, specific infarct locations may be associated with a poorer outcome in this exploratory re-analysis of the NINDS rt-PA Study.

Teaching Neuro Images : Vein of Galen aneurysm mimicking pineal mass in a young adult

A 22-year-old man presented with intractable progressive headaches over 2 months. Noncontrast head CT and contrast-enhanced MRI scan revealed a hyperdense pineal-based mass (figure, A and B). Arteriogram was normal (figure, C and D).

Bilateral intraventricular mass in a child

An 8-year-old boy presented with a history of holocranial headache for 4 weeks which was mild to moderate in intensity. There was history of intermittent vomiting for the same duration. The patient was drowsy for the last 10 days. Non-contrast CT scan of head showed a space-occupying lesion in lateral ventricles with hydrocephalus. MRI showed a large lobulated well-defined heterogeneous mass lesion filling up both lateral ventricles at the posterior and temporal horns, bilaterally reaching up to the level of the foramen magnum. The mass lesion was hypointense on T2-weighted images (T2W) and isointense to grey mater on T1W images. On contrast images there was intense homogeneous enhancement seen at the lesion (Fig. 1). Right fronto-temporo-parietal craniotomy with decompression of the tumor was performed. Perioperatively, the tumor was yellowish in color, firm, not able to be aspirated and minimally vascular. Clinical diagnosis of choroid plexus tumor was considered.

The Case Files

FigureFigureA 27-year-old woman with no significant past medical history arrived at the emergency department complaining of persistent headache three days after a spontaneous vaginal delivery. The patient's recent hospital stay was notable for epidural anesthesia and epidural blood patch for lumbar puncture-induced headache performed the day after delivery. The patient had complained of persistent headache since delivery. She denied any positional quality to the headache and any light or sound sensitivity. She had no nuchal rigidity or fevers, and had a nonfocal neurologic exam. All other reviews of systems were within normal limits. She had no family or personal history of intracranial hemorrhage or central venous thrombosis. Our differential included pre-eclampsia, continued cerebrospinal fluid leak from failed blood patching, and meningitis. Her triage and subsequent blood pressures were elevated above her baseline, so a pre-eclampsia workup was initiated. Our initial plan was to evaluate for other causes of headache via a non-contrast head CT scan. The pre-eclampsia workup and her labs were negative, and her pain was better controlled with parental opioids. Her head CT demonstrated pneumocephalus. This is an uncommon complication of epidural anesthesia and blood patching due to the infusion of a small amount of saline, which may contain gas bubbles, into the epidural space. Most cases of pneumocephalus are caused by trauma or neurosurgical interventions. The patient suffered no consequences from the intraventricular free air aside from a headache that subsided on hospital day five, which correlated with reabsorption of the air pocket. She was admitted strictly for pain control, and her subsequent CT scans were negative.

Foreign Body Embedded in Anterior Chamber Angle

Introduction. We present a case of a metallic foreign body embedded in the anterior chamber angle. After standing in close proximity to a construction worker breaking a tile, a 26-year-old woman using soft contact lens for the correction of mild myopia presented to emergency department for evaluation of a foreign body sensation of her right eye. Methods and Results. Diagnosis was confirmed by gonioscopic examination and a noncontrast CT scan of head and orbits. The foreign body was removed by an external approach without utilizing a magnet. The patient's final outcome was favorable. Discussion. The above is a rare clinical situation, which is impossible to detect on slit-lamp examination without a gonioscopic view. Proper imaging and a specific management are mandatory in order to achieve favorable outcome.

A descriptive epidemiological study on stroke in Kampala, Uganda: a hospitalbased study

Background Basic stroke features are hardly known in sub-Saharan countries, and no data are available in Uganda. Objective To characterize patients presenting with clinical stroke to Mulago Hospital. Design Descriptive epidemiological study. Setting Mulago National referral Hospital in Kampala, Uganda. Participants Patients presenting with clinical stroke from 1st July to 30th November 2006. Patients with confirmed stroke had comprehensive assessments for stroke risk factors. Results Among 139 patients presenting with clinical stroke, 127 had a non-contrast head CT scan and 12 died prior to scan. Eighty five patients were confirmed to have stroke while 42 had non stroke lesions. Among patients with confirmed stroke, 77.6% had ischemic stroke while 22.4% had hemorrhagic stroke. The mean age for all stroke patients was 62.2 ± 16.2 yrs and 51.8% were men. The incidence of both ischemic and hemorrhagic stroke increased with age. Atherosclerotic stroke was the most common ischemic stroke etiology, observed in 43.5% patients with ischemic stroke, while intraparenchymal hemorrhage was the most common hemorrhagic stroke etiology, observed in 78.9% of patients with hemorrhagic stroke. Hypertension was the commonest risk factor with more than 50% of all stroke patients reporting a history of hypertension, and more than half found to have blood pressure greater than 140/90 mm Hg. Physical inactivity and hypercholesterolemia were encountered in more than 36% and 30% of patients with ischemic and haemorrhagic strokes respectively.

212 The Impact of Physician Risk Tolerance and Attitudes Toward Clinical Decision Rules on Head CT Utilization for Trauma Patients in the Emergency Department

Despite the development of well-validated evidence-based clinical decision rules (CDR) designed to reduce variability and utilization of head CT in patients who present with minor head injury, there is concern for increasing and inappropriate use of imaging for these patients. Physician risk tolerance, including fear of malpractice as well as misgivings regarding the use and accuracy of clinical decision rules are frequently cited as contributing to suboptimal utilization of head CT. Our objective was to determine whether physician risk tolerance or attitudes toward CDR were associated with utilization of non-contrast CT of the head in patients with head trauma. Our hypothesis was that neither risk tolerance nor attitudes towards CDR would be associated with utilization. We prospectively surveyed 39 attending emergency physicians at a single urban tertiary level-1 trauma center to assess their risk tolerance using 3 previously validated scales: the Risk Tolerance Scale (RTS), Stress from Uncertainty Scale (SUS) and Malpractice Fear Scale (MFS). Attitudes toward CDR were assessed by modifying a previously validated survey designed to measure physician attitudes toward clinical practice guidelines. Physician demographic characteristics, including age, sex, years in practice, clinical hours worked, 3 or 4-year residency training, and prior lawsuit involvement, were also captured. We reviewed all non-contrast head CT scans performed for head injury over the prior 2 years and collected data on patient demographics, triage acuity and time of day at presentation. Using a logistic regression model, the influence of physician and patient factors on the decision to obtain imaging was assessed. Thirty-seven of 39 physicians (95%) completed the survey. A total of 7932 head CT scans for patients with trauma were performed during the study period. Increased head CT utilization was associated with increasing patient age (P<0.0001), higher triage acuity (P<0.0001), male sex (P<0.0001) and time of presentation (overnight greater than evening or day) (P<0.0012). Neither physician demographic and risk tolerance characteristics, nor attitudes toward CDR were significantly associated with utilization. However, the prevalence of CDR use for ordering head CT in patients with minor head injury was low: while 95% of physicians surveyed regularly used CDR when they ordered diagnostic tests, only 35% used them when ordering head CT for patients with minor head injury, and 43% felt CDR for minor head injury were cumbersome and difficult to remember. Utilization of head CT in patients with head injury is associated with patient factors but not physician risk tolerance or attitudes toward CDR, and the prevalence of CDR use for imaging in head injury is low. Future initiatives to reduce head CT utilization in trauma patients should focus on identifying low risk patients in which diagnostic imaging can be safely withheld by educating physicians on CDR and facilitating their use by integration of clinical decision support into electronic order entry software.

Yield of catheter angiography in patients with intracerebral hemorrhage with and without intraventricular extension

Background and aimThe role of imaging for the detection of vascular lesions in patients with intracerebral hemorrhage (ICH) is poorly defined. A study was undertaken to compare the yield of...

Index of Suspicion * Case 1: Fever, Barking Cough, Stridor, and Rash in an Infant * Case 2: Erythematous Papulovesicular Rash in a 3-month-old Girl * Case 3: Vomiting and Unrelenting Headaches in a 5-year-old Girl

A 6-month-old boy presents with a temperature of 38.9°C and barking cough of 3 days’ duration as well as a rash over his body for 1 day. On physical examination, his temperature is 37.5°C, respiratory rate is 28 breaths/min, and blood pressure is 87/52 mm Hg. He appears nontoxic and has a barking cough, injected conjunctiva with whitish discharge, dry lips, mild inspiratory stridor, a blanching erythematous maculopapular rash on his trunk and extremities, and small cervical lymph nodes. The rest of his physical findings are normal. His Hgb is 12.8 g/dL (128 g/L), WBC count is 11.7×103/mcL (11.7×109/L) with 75% neutrophils and 23% lymphocytes, and platelet count is 515×103/mcL (515×109/L). His stridor is considered to be due to viral croup, and he is treated with intramuscular (IM) dexamethasone and nebulized racemic epinephrine. A lateral neck radiograph reveals widening of the retropharyngeal space (Fig. 1), and he is started on clindamycin. CT scan of the neck reveals a right retropharyngeal abscess (Fig. 2). He continues to have high spiking fevers and experiences stridor at rest. He is started on IM dexamethasone every 6 hours, and his fever subsides the following day. Figure 1. Lateral neck radiograph showing widening of the retropharyngeal space. Figure 2. CT scan of the neck showing a right retropharyngeal abscess (arrow). On hospital day 6, the corticosteroids are stopped, but the fever returns the following day. Two days later, an erythematous maculopapular rash reappears, and the child’s lips are dry and cracked. On day 10, repeat CT scan shows that the retropharyngeal abscess has resolved. An additional imaging study reveals the cause of his symptoms. A 3-month-old previously healthy girl presents to the ED with a 1-day history of a blistering rash. Her parents noted an erythematous area on her occiput after …