Utility of head CT in the evaluation of vertigo/dizziness in the emergency department

Acute dizziness (including vertigo) is a common reason to visit the emergency room, and imaging with head CT is often performed initially to exclude a central cause. In this study, consecutive patients presenting with dizziness and undergoing head CT were retrospectively reviewed to determine diagnostic yield. Four hundred forty-eight consecutive head CTs in a representative sample of dizzy emergency room (ER) patients, including patients with other neurological symptoms, were reviewed to identify an acute or subacute cause for acute dizziness along with the frequency and modalities used in follow-up imaging. The diagnostic yield for head CT ordered in the ER for acute dizziness is low (2.2 %; 1.6 % for emergent findings), but MRI changes the diagnosis up to 16 % of the time, acutely in 8 % of cases. Consistent with the American College of Radiology appropriateness criteria and the literature, this study suggests a low diagnostic yield for CT in the evaluation of acute dizziness but an important role for MRI in appropriately selected cases.     

Syncope and head CT scans in the emergency department

Context Patients presenting with syncope to the emergency department (ED) of a community hospital were evaluated. Aim The objective of this study is to examine the use and results of head computerized tomography (CT) scans in patients presenting with syncope to the ED of a community hospital. Settings and design A retrospective chart review of patients presenting with syncope to the emergency room was conducted. Methods and materials We reviewed the charts of patients who presented to the ED over a 6-month period with syncope. When performed, head CT scan findings were noted, and their relationship to the clinical presentation was examined. Results One hundred twenty-eight patients were identified. Forty-four patients had their head CT scans performed. In 1 patient, the CT scan showed evidence of infarction in the posterior circulation. In 19 patients, the head CT scan was normal. Twenty-four patients had abnormal findings unrelated to the ED presentation. Conclusions Head CT scans were commonly used in our series of syncope patients. Abnormal findings pertinent to the syncope were observed in only 1 patient. A prospective study examining yield in a larger series of patients may help define the utility of this neuroimaging modality in syncope.     

Yield of head CT in the alcohol-intoxicated patient in the emergency department

We aimed to determine the yield of positive head computed tomography (CT) findings among suspected alcohol-intoxicated patients presenting to the emergency department (ED). Our secondary aim was to determine if elderly intoxicated patients were more likely to have an intracranial injury. We identified patients suspected of alcohol intoxication who underwent CT scanning in the ED over a 4-year period. Pre-determined data elements including demographics, diagnosis, and disposition were extracted using a pre-formatted data sheet by blinded abstractors. “Positive” CT was defined as evidence of any type of intracranial hemorrhage. A total of 2,671 subjects with suspected alcohol intoxication and a head CT were identified. Fifty out of the 2,671 (1.9%) had a positive CT. Among CT scans of elderly (≥60 years of age) subjects, 15/555 (2.7%, 95% CI = 1.4–4.1%) were positive compared with 35/2,116 (1.7%, 95% CI = 1.1–2.2%) among those <60 years of age (p = 0.11). The yield of positive head CT among alcohol-intoxicated patients was low, at 1.9%. An age cutoff of 60 years in this population did not predict a significantly higher positive rate.     

Radiation exposure among patients with the highest CT scan utilization in the emergency department

The risk of cancer from computed tomography (CT) scan radiation is a rising concern in the medical field. Our objectives were to determine how many patients received more than ten CT scans in an academic emergency department (ED) over the course of 7 years and to quantify their radiation exposure and lifetime attributable risk of cancer. An electronic chart review was performed at our urban academic institution with an annual census of 110,000 patients. All patients who underwent a CT scan performed during ED management between the dates of January 2001 and December 2007 were identified. Specific predetermined data elements (e.g., subject demographics, type of CT scan) were extracted by two researchers blinded to hypothesis, using a preformatted data form. After identifying patients with more than ten CTs performed during the study period, radiation exposure was calculated based on accepted and reported radiation doses for the respective anatomic CTs, and lifetime attributable cancer risk was calculated based on the seventh report of the Biological Effects of Ionizing Radiation (BEIR VII) projections. Over the 7-year study period, 24,393 patients received 34,671 CT scans. The vast majority of patients (17,909) received a single CT. Twenty-six (0.1 %) patients received more than ten CTs totaling 374 scans with an average radiation exposure of 83.4 mSv. The maximum lifetime attributable risk for any individual in this cohort was 1.7 % above the baseline cancer risk. Among those undergoing CT imaging in our ED, high-exposure patients (greater than ten scans) constituted a significant minority, while more than one in four patients underwent more than one CT scan during the study period. While the presumed overall risk of radiation-induced cancer continues to be low, it is important for the emergency physician to use clinical knowledge as well as concern for the patient when utilizing radiographic imaging. Increasing attributable cancer risk may have important public health implications in the future, regardless of the low individual risk.     

Effect of emergency department CT on neuroimaging case volume and positive scan rates

RATIONALE AND OBJECTIVES: The authors performed this study to determine the effect a computed tomographic (CT) scanner in the emergency department (ED) has on neuroimaging case volume and positive scan rates. MATERIALS AND METHODS: The total numbers of ED visits and neuroradiology CT scans requested from the ED were recorded for 1998 and 2000, the years before and after the installation of a CT unit in the ED. For each examination type (brain, face, cervical spine), studies were graded for major findings (those that affected patient care), minor findings, and normal findings. The CT utilization rates and positive study rates were compared for each type of study performed for both years. RESULTS: There was a statistically significant increase in the utilization rate after installation of the CT unit (P < .001). The fractions of studies with major findings, minor findings, and normal findings changed significantly after installation of the CT unit for facial examinations (P = .002) but not for brain (P = .12) or cervical spine (P = .24) examinations. In all types of studies, the percentage of normal examinations increased. In toto, there was a significant decrease in the positive scan rate after installation of the CT scanner (P = .004). CONCLUSION: After installation of a CT scanner in the ED, there was increased utilization and a decreased rate of positive neuroradiologic examinations, the latter primarily due to lower positive rates for facial CT scans.     

Radiology resident interpretation of on-call CT pulmonary angiograms

RATIONALE AND OBJECTIVES: To evaluate the interpretation of computed tomographic pulmonary angiograms performed outside of regular reporting hours, comparing the initial interpretation by the radiology resident to the attending radiologist. MATERIALS AND METHODS: Records for 840 consecutive computed tomographic pulmonary angiograms (CTPA) performed outside of regular reporting hours at two tertiary referral centers from January 1, 2004-December 31, 2005 were reviewed. The preliminary interpretation by the on-call radiology resident was compared to the subsequent final report issued by a subspecialty trained chest radiologist. Studies were stratified as positive, negative, or equivocal for pulmonary embolus. Cases with discordant interpretations or negative CTPA were reviewed to determine impact on clinical outcome. Patients were followed up to 12 months after CTPA to document any subsequent thromboembolic event. RESULTS: Sixteen percent (131/840) of CTPAs were reported positive by the staff radiologist. There was agreement in 90% (752/840) of studies (P = .76, 95% confidence interval, 0.71-0.81) with 86% (114/133) agreement for studies interpreted as positive by residents, 95% (582/612) for studies interpreted as negative by residents, and 63% (60/95) for studies interpreted as equivocal by residents. Studies of optimal quality had higher interobserver agreement than studies of suboptimal quality (P < .0001). In-patient studies were more likely to be positive than emergency room patients (20% vs. 13%) (P = .004). No adverse clinical outcomes were attributed to discordant interpretations. CONCLUSIONS: Radiology residents provide a high level interpretation of on-call CTPA studies, achieving good concordance with the attending radiologists' assessment.     

Yield of head CT for acute findings in patients presenting to the emergency department

ObjectivesThe aim of our study was to evaluate the yield of head CT in the ED in different age groups and different referral indications.Patients and methodsRecords of one large academic tertiary care ED were retrospectively reviewed for consecutive adult patients who underwent a head CT between January 1st 2017 and February 10th 2017. CT referral forms and interpretations were obtained and evaluated for demographics, referral indications, and findings.Scans were divided into three groups: acute findings, chronic findings, and normal. The cohort was divided into three age groups. Associations between referral indications and acute findings were calculated.ResultsOverall, 1536 of adult patients with ED head CT were included. Acute findings were found in 239/1536 (15.5%) of the CTs. The frequency of acute findings increased with age (p = 0.027). The most common acute findings were brain hemorrhage (32.6%), infarct (27.6%), and mass (23%). The top three referral indications were focal neurologic deficit (28%), trauma (24.7%), and headache (17.5%).The rates of positive acute findings for different referral indications were seizure 27%, confusion 20%, syncope 19%, focal neurologic deficit 16%, head injury 15%, headache 12%, and dizziness 8%.ConclusionThis study shows the yield of ED head CT for acute findings for different age groups and for different referral indications. The frequency of acute findings increased with age. Suspected seizure had the highest association with an acute finding, whereas dizziness had the lowest association.     

Promoting head CT exams in the emergency department triage using a machine learning model

Neuroradiology - In this study, we aimed to develop a novel prediction model to identify patients in need of a non-contrast head CT exam during emergency department (ED) triage. We collected data...     

Scenarios to improve CT head utilization in the emergency department delineated by critical results reporting

Emergency Radiology - Increasing use of advanced imaging in the emergency department (ED) has resulted in higher cost without better outcomes. Our goal was to evaluate the yield of CT head exams by...     

Retrospective analysis of the application of CT scan in the emergency department to screen clinically asymptomatic COVID-19 before hospital admission

Emergency Radiology - The necessity to identify and isolate COVID-19 patients to avoid intrahospital cross infections is particularly felt as a challenge. Clinically occult SARS-CoV-2 infection...     

CT of small-bowel ischemia associated with obstruction in emergency department patients: diagnostic performance evaluation

PURPOSE: To retrospectively evaluate the diagnostic performance of computed tomography (CT) for detection of small-bowel ischemia in emergency department patients with abdominal pain and to compare the prospective interpretation with a retrospective interpretation by using surgical or pathologic findings as the reference standard. MATERIALS AND METHODS: The HIPAA-compliant study was approved by the institutional review board, and patients consented to research authorization. Sixty patients (61 examinations) (25 male, 35 female patients; median age, 67 years; range, 0.9-89.7 years) with acute abdominal pain underwent immediate abdominal and pelvic CT and subsequent surgery of the small bowel within 7 days of CT. Prospective radiologic reports were reviewed for diagnosis of small-bowel obstruction and ischemia. Two gastrointestinal radiologists performed blinded, independent, retrospective review of the CT studies with no clinical data other than presence of acute abdominal pain. The reviewers categorized CT signs of obstruction and ischemia and estimated diagnostic certainty. Discordant findings were resolved by consensus review by a third gastrointestinal radiologist. CT interpretations were compared with prospective interpretations and surgical or pathologic findings. Sensitivity and specificity estimates with confidence intervals were calculated. Fisher exact and chi2 tests were used to assess associations between CT signs and the diagnosis of ischemia; kappa statistics were used to estimate agreement between readers. RESULTS: In 27 (44%) of 61 CT studies, small-bowel ischemia was surgically or pathologically confirmed. Sensitivity and specificity for the diagnosis of ischemia were, respectively, 14.8% and 94.1% for prospective interpretations, 29.6% and 91.2% for reader 1, 40.7% and 85.3% for reader 2, and 51.9% and 88.2% for the consensus review. Decreased segmental enhancement was the most specific sign for small-bowel ischemia (P = .001), and its recognition would have improved the diagnostic performance of all readers. There was a significant association of the small-bowel feces sign with the presence of small-bowel ischemia (P = .046). CONCLUSION: Diagnostic performance assessment of CT for the diagnosis of small-bowel ischemia revealed poor prospective interpretation sensitivity.     

The use of MRI scan of knee injuries in an emergency department

We present a retrospective study of the number of arthroscopically verified total meniscus and cruciate ligament tears seen in our Emergency department one year before, and one year after introducing magnetic resonance imaging (MRI) as a diagnostic tool. The number of total ruptures of the anterior cruciate ligament increased from 34 (1.7% of total 2003 patients) to 67 (2.9% of total 2277). The number of ruptures of the medial meniscus increased from 42 (2.1%) to 87 (3.8%). The number of ruptures of the lateral meniscus remained unchanged. In the first 12 months after introducing MRI we ordered 513 (23%) scans of the total number of 2277 patients with an acute knee condition. Thirty-nine (8%) of these were described with no pathology, 227 (44%) showed total meniscus or cruciate ligament tears. The remaining 247 (48%) were mainly degenerative or partial injuries. The cost per additional new diagnosis was approximately USD 800. The introduction of MRI has enabled us to identify a larger number of patients with meniscus and cruciate ligament injuries.     

应用模拟低剂量法行新生儿头颅CT扫描

Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.     

应用模拟低剂量法行新生儿头颅CT扫描

目的 评估降低扫描剂量对新生儿头颅64层MSCT图像的影响,计算最低剂量.方法 选择57例颅内出血患儿进行MSCT扫描,获得每例患儿后颅窝、基底节区及半卵圆中心3个层面实际扫描原始图像171幅.应用噪声添加工具,模拟扫描剂量减少25%、40%、50%和70%时的扫描情况,将相对应的不同模拟噪声添加到原始图像上,共获得5组855幅图像.2名放射科医师独立对图像质量进行评估,图像分析包括图像质量和图像噪声,即诊断接受率评分、图像主观噪声评分及客观噪声指数(noise index,NI).诊断接受率和图像主观噪声均采用5分制评分.图像噪声测量方法:分别在后颅窝、基底节区及半卵圆中心3个层面的小脑实质、丘脑及放射冠脑白质上放置ROI.测量NI值,然后计算平均值.应用Kappa法评价2名医师评定结果间的一致性,SPearman线性相关分析用于评估NI和诊断接受率评分之间的关系.结果 患者原始扫描剂量、模拟剂量分别减少25%、40%、50%、70%时图像诊断接受率评分分别为(4.47±0.51)、(3.96±0.33)、(3.21±0.45)、(2.92.±0.32)、(1.85±0.57)分,主观噪声评分(1.62±0.48)、(1.99±0.48)、(2.76±0.81)、(3.19±0.67)、(4.27±0.54)分,NI为1.90±0.19、2.17±0.20、2.44±0.25、2.68±0.28、3.37±0.39.2名医师的诊断接受率评分呈很好的一致性(K=0.860,P=0.017),图像噪声评分呈中度一致性(K=0.630,P=0.022).NI与诊断接受率评分之间呈正相关性(r=0.826,P=0.001).模拟扫描剂量减少40%,即管电流为107 mAs时,NI是2.44,诊断接受率评分是3.21,符合临床诊断需求.结论 在NI为2.44,模拟扫描剂昔减少40%时,可获得能满足临床诊断的图像.     

应用模拟低剂量法行新生儿头颅CT扫描

Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.     

应用模拟低剂量法行新生儿头颅CT扫描

Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.     

应用模拟低剂量法行新生儿头颅CT扫描

Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.     

应用模拟低剂量法行新生儿头颅CT扫描

Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.