Canadian Computed Tomography Research Articles

Is the Canadian CT Head Rule Applicable to Patients with Minimal Head Trauma

The Canadian Computed Tomography (CT) Head Rule was developed and validated in patients with minor head trauma involving loss of consciousness or

Application of the Canadian Computed Tomography Head Rule to Patients With Minimal Head Injury

Two clinical decision rules, the Canadian CT Head Rule and the New Orleans Criteria, set the standard to guide clinicians in determining which patients with minor head trauma need computed tomography (CT) imaging. Both rules were derived with patients with minor head injury who had had a loss of consciousness or witnessed disorientation. No evidence exists for evaluating patients and need for CT imaging with minimal head injury; that is, patients who had a head injury but no loss of consciousness or disorientation and therefore would have been excluded from the Canadian CT Head Rule and New Orleans Criteria trials. We evaluate the Canadian CT Head Rule in patients with head injury without loss of consciousness or witnessed disorientation (minimal head injury). We studied a prospective convenience sample of patients with minimal head injury who received head CTs as part of their evaluations in the emergency department (ED). Participants were enrolled after head CT was ordered, but before the physician received the imaging results. Physicians were surveyed on their clinical reasoning for ordering imaging in this low-risk cohort of patients. Physicians surveyed consisted of ED attending physicians and senior-level emergency medicine residents. Final patient disposition was recorded when it became available. Patients with positive CT findings had their medical records reviewed for specific disposition, admission length of stay, ICU stay, and any operative or procedural interventions. Two hundred forty patients with minimal head injury were enrolled. Five patients (2.1%) had head CTs that were positive for intracranial hemorrhage. All instances of intracranial hemorrhage occurred in patients who were at high or moderate risk by the Canadian CT Head Rule (2 high risk [age], 3 moderate risk [mechanism]). No patient with intracranial hemorrhage went to the ICU or underwent any intervention; the average hospital length of stay was 1.25 days. The Canadian CT Head Rule was 100% sensitive (95% confidence interval 40% to 100%) and 29% specific (95% confidence interval 23% to 35%) for the presence of intracranial hemorrhage. Physicians listed their own reassurance (24.6%), patient reassurance (24.2%), patient expectation (14.6%), and reduction of legal liability (11.7%) as the rationale for ordering head CT in patients with minimal head injury. Shared decisionmaking was used in 51% of cases. Risk of intracranial hemorrhage in patients with minimal head injury was very low, and even in patients found to have an intracranial hemorrhage, none had any serious adverse outcome (eg, death, intubation, prolonged hospitalization, surgical procedure). The Canadian CT Head Rule was 100% sensitive in this small cohort of patients with minimal head injury. Among our study cohort, which specifically included only patients who had CT scanning, applying the Canadian CT Head Rule may have reduced the need for CT, potentially saving costs and resources. However, because many patients with minimal head injury who present to the ED may not have CTs, it is unclear what effect the broad application of this rule would have on overall CT use. Providers' rationale for obtaining CT was multifactorial. These represent barriers that may need to be overcome before physicians are comfortable changing CT ordering patterns in this group of head injury patients.

Criteria for Performing Cranial Computed Tomography for Chinese Patients With Mild Traumatic Brain Injury: Canadian Computed Tomography Head Rule or New Orleans Criteria?

Computed tomography (CT) provides the primary diagnostic evidence for traumatic brain injury (TBI), but few positive traumatic findings are discovered in patients with mild TBI. In China, there are no existing criteria for selecting patients with mild TBI to undergo CT, and almost all of these patients undergo cranial CT in the emergency department. This retrospective study was performed to evaluate the necessity of cranial CT among patients with mild TBI, as well as the feasibility of 2 popular criteria (Canadian CT head rule [CCHR] and New Orleans Criteria [NOC]) in China. Patients with mild TBI who underwent cranial CT within 24 hours of the trauma were included in our institute. Two neurosurgeons reviewed the CT images independently to identify positive CT findings. The sensitivity and specificity of CCHR and NOC for positive CT findings related to TBI were analyzed. Finally, this study included 625 patients. Positive CT findings related to TBI were discovered in 13.12% (82/625) of these patients on cranial CT, and 6.88% (43/625) of them were admitted to the hospital for further management. Ultimately, 11 patients (1.76%, 11/625) underwent neurosurgery. In this study, the sensitivities of both the CCHR and NOC were 100%, but the specificity of CCHR was 43.36% and that of NOC was 33.12%. Based on our study, both CCHR and NOC have high sensitivity for the detection of positive CT findings related to head trauma in patients with mild TBI.

Patient-Centered Decision Support: Formative Usability Evaluation of Integrated Clinical Decision Support With a Patient Decision Aid for Minor Head Injury in the Emergency Department.

BackgroundThe Canadian Computed Tomography (CT) Head Rule, a clinical decision rule designed to safely reduce imaging in minor head injury, has been rigorously validated and implemented, and yet expected decreases in CT were unsuccessful. Recent work has identified empathic care as a key component in decreasing CT overuse. Health information technology can hinder the clinician-patient relationship. Patient-centered decision tools to support the clinician-patient relationship are needed to promote evidence-based decisions.ObjectiveOur objective is to formatively evaluate an electronic tool that not only helps clinicians at the bedside to determine the need for CT use based on the Canadian CT Head Rule but also promotes evidence-based conversations between patients and clinicians regarding patient-specific risk and patients’ specific concerns.MethodsUser-centered design with practice-based and participatory decision aid development was used to design, develop, and evaluate patient-centered decision support regarding CT use in minor head injury in the emergency department. User experience and user interface (UX/UI) development involved successive iterations with incremental refinement in 4 phases: (1) initial prototype development, (2) usability assessment, (3) field testing, and (4) beta testing. This qualitative approach involved input from patients, emergency care clinicians, health services researchers, designers, and clinical informaticists at every stage.ResultsThe Concussion or Brain Bleed app is the product of 16 successive iterative revisions in accordance with UX/UI industry design standards. This useful and usable final product integrates clinical decision support with a patient decision aid. It promotes shared use by emergency clinicians and patients at the point of care within the emergency department context. This tablet computer app facilitates evidence-based conversations regarding CT in minor head injury. It is adaptable to individual clinician practice styles. The resultant tool includes a patient injury evaluator based on the Canadian CT Head Rule and provides patient specific risks using pictographs with natural frequencies and cues for discussion about patient concerns.ConclusionsThis tool was designed to align evidence-based practices about CT in minor head injury patients. It establishes trust, empowers active participation, and addresses patient concerns and uncertainty about their condition. We hypothesize that, when implemented, the Concussion or Brain Bleed app will support—not hinder—the clinician-patient relationship, safely reduce CT use, and improve the patient experience of care.

Canadian CT head rule and New Orleans Criteria in mild traumatic brain injury: comparison at a tertiary referral hospital in Japan.

We compared Canadian computed tomography (CT) head rule (CCHR) and New Orleans Criteria (NOC) in predicting important CT findings in patients with mild traumatic brain injury (TBI). We included 142 consecutive patients with mild TBI [Glasgow coma scale (GCS) 13–15] who showed at least one of the risk factors stated in the CCHR or the NOC. We introduced two scores: a Canadian from the CCHR and a New Orleans from the NOC. A patient’s score represented a sum of the number of positive items. We examined the relationship between scores or items and the presence of important CT findings. Only the Canadian was significantly associated with important CT findings in multivariate analyses and showed higher area under the receiver operating characteristic curve (AUC) either in all 142 patients (GCS 13–15: P = 0.0130; AUC = 0.69) or in the 67 with a GCS = 15 (P = 0.0128, AUC = 0.73). Of items, “>60 years” or “≥65 years” included in either guideline was the strongest predictor of important CT finding, followed by “GCS < 15 after 2 h” included only in the CCHR. In a tertiary referral hospital in Japan, CCHR had higher performance than the NOC in predicting important CT findings.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-016-1781-9) contains supplementary material, which is available to authorized users.

Canadian Computed Tomography Head Rule and Its Impact on Singaporean Practice

Introduction We aim to determine the usefulness of the Canadian Computed Tomography (CT) Head Rule in patients who present with minor and minimal head injury to the emergency department. Methods Clinical information was retrospectively collected and the need for CT head was evaluated. The primary outcome measure was the requirement for neurological intervention. The secondary outcome measure was brain injury requiring admission or neurological follow-up. Results A total of 1127 cases were reviewed. About 6.3% had clinically important brain injury; and 1.2% required neurological intervention. The high-risk factors were 45.2% sensitive (95% confidence interval [CI]=27.8-63.7%) and 76.2% specific (95% CI=73.5-78.7%) for predicting need for neurological intervention. All seven risk factors were 73.2% sensitive (95% CI=61.2-82.7%) and 69.8% specific (95% CI=66.9-72.5%) for predicting clinically important brain injury. Overall, the rule had a positive predictive value of 14.0 (95% CI=10.7-18.1) and negative predictive value of 97.5 (95% CI=96.0-98.4). Conclusions In this retrospective validation of the Canadian CT Head Rule in the Singaporean context, we conclude that the lower sensitivity of the rule could be attributed to local neurosurgical practice, lack of application of the rule among clinicians and inclusion of patients with minimal head injury. Practically, the high NPV will mean that patients who do not fulfill the rule can be safely discharged with head injury advice, without the need for a scan. The judicious use of CT head can achieve savings for our health-care system. (Hong Kong j.emerg.med. 2015;22:359-363)

Accuracy of Canadian CT head rule in predicting positive findings on CT of the head of patients after mild head injury in a large trauma centre in Saudi Arabia.

Investigation of unjustified computed tomography (CT) scan in patients with minor head injury is lacking in Saudi Arabia. The purpose of the study was to evaluate the compliance and effectiveness of the Canadian computed tomography head rule (CCHR) in our emergency department (ED) and trauma centre and also to reduce the number of unjustified CT studies of the head in the centre. A retrospective study of 368 ED patients with minor head injury was conducted. Patients who underwent CT scan between July 2010 and June 2011 were selected from the ED head trauma registry by systematic randomisation. The CCHR was retrospectively applied on the patients' charts to calculate the prevalence of unjustified head CT scans. A separate survey was conducted to evaluate three emergency physicians' level of awareness about the CCHR and their ability to determine the necessity of CT scans with various clinical scenarios of head injury. The prevalence of unjustified CT scans as per the CCHR was 61.8% (95% confidence interval (CI) 56.5-66.9%). Approximately 5% of the sample had positive CT findings with 95% CI 2.9-7.6%. The CCHR correctly identified 12 cases with positive CT findings with 66.67% sensitivity. Only 24 (6.7%) had Glasgow coma scale scores less than 15 (13/14). The Glasgow coma scale correctly identified only two cases with positive CT findings with 11.11% sensitivity. The percentage of skull fracture (0.9% vs 5%, P=0.030) was significantly lower in patients with unjustified CT scans than in patients with clinically justified CT scans. There was fair to substantial agreement between the ED physicians and the CCHR (κ=35-61%). Two ED physicians identified all cases of justified CT scan with 100% sensitivity (95% CI 71.51-100%). The level of education regarding the CCHR was found to be optimal among emergency physicians using a case-based scenario survey. The CCHR was found to have a poor compliance potential in the busy ED of our trauma centre and the prevalence of unjustified cranial CT scans remained high.

Head CT scan in Iranian minor head injury patients: evaluating current decision rules.

The objective of this study is to select one of the seven available clinical decision rules for minor head injury, for managing Iranian patients. This was a prospective cohort study evaluating medium- or high-risk minor head injury patients presenting to the Emergency Department. Patients with minor head trauma who were eligible for brain imaging based on seven available clinical decision rules (National Institute for Health and Clinical Excellence (NICE), National Emergency X-Radiography Utilization Study (NEXUS)-II, Neurotraumatology Committee of the World Federation of Neurosurgical Societies (NCWFNS), New Orleans, American College of Emergency Physicians (ACEP) Guideline, Scandinavian, and Canadian computed tomography (CT) head rule) were selected. Subjects were underwent a non-contrast axial spiral head CT scan. The outcome was defined as abnormal and normal head CT scan. Univariate analysis and stepwise linear regression were applied to show the best combination of risk factors for detecting CT scan abnormalities. Five hundred patients with minor head trauma were underwent brain CT scan. The following criteria were derived by stepwise linear regression: Glasgow Coma Scale (GCS) less than 15, confusion, signs of basal skull fracture, drug history of warfarin, vomiting more than once, loss of consciousness, focal neurologic deficit, and age over 65 years. This model has 86.15 % (75.33-93.45 %) sensitivity and 46.44 % (46.67-51.25 %) specificity in detecting minor head injury patients with CT scan abnormalities (95 % confidence interval). Of seven decision rules, only the Canadian CT Head Rule possesses seven of the eight high-risk factors associated with abnormal head CT results which were identified by this study. This study underlines the Canadian CT Head Rule's utility in Iranian minor head injury patients. Our study encourages researchers to evaluate available guidelines in different communities.

264 Application of the Canadian Computed Tomography Head Rule to a Very Low Risk Minor Head Injury Population

264 Application of the Canadian Computed Tomography Head Rule to a Very Low Risk Minor Head Injury Population

International Survey of Emergency Physicians’ Awareness and Use of the Canadian Cervical‐Spine Rule and the Canadian Computed Tomography Head Rule

The derivation and validation studies for the Canadian Cervical-Spine (C-Spine) Rule (CCR) and the Canadian Computed Tomography (CT) Head Rule (CCHR) have been published in major medical journals. The objectives were to determine: 1) physician awareness and use of these rules in Australasia, Canada, the United Kingdom, and the United States and 2) physician characteristics associated with awareness and use. A self-administered e-mail and postal survey was sent to members of four national emergency physician (EP) associations using a modified Dillman technique. Results were analyzed using repeated-measures logistic regression models. The response rate was 54.8% (1,150/2,100). Reported awareness of the CCR ranged from 97% (Canada) to 65% (United States); for the CCHR it ranged from 86% (Canada) to 31% (United States). Reported use of the CCR ranged from 73% (Canada) to 30% (United States); for the CCHR, it was 57% (Canada) to 12% (United States). Predictors of awareness were country, type of rule, full-time employment, younger age, and teaching hospital (p < 0.05). Significant differences in use of the CCR by country were observed, but not for the CCHR. Teaching hospitals were more likely to use the CCR than nonteaching hospitals, but less likely to use the CCHR. This large international study found notable differences among countries with regard to knowledge and use of the CCR and CCHR. Awareness and use of both rules were highest in Canada and lowest in the United States. While younger physicians, those employed full-time, and those working in teaching hospitals were more likely to be aware of a decision rule, age and employment status were not significant predictors of use. A better understanding of factors related to awareness and use of emergency medicine (EM) decision rules will enhance our understanding of knowledge translation and facilitate strategies to enhance dissemination and implementation of future rules.