Head CTs Research Articles

Accurate Detection of Inner Ears in Head CTs Using a Deep Volume-to-Volume Regression Network with False Positive Suppression and a Shape-Based Constraint.

Cochlear implants (CIs) are neural prosthetics which are used to treat patients with hearing loss. CIs use an array of electrodes which are surgically inserted into the cochlea to stimulate the auditory nerve endings. After surgery, CIs need to be programmed. Studies have shown that the spatial relationship between the intra-cochlear anatomy and electrodes derived from medical images can guide CI programming and lead to significant improvement in hearing outcomes. However, clinical head CT images are usually obtained from scanners of different brands with different protocols. The field of view thus varies greatly and visual inspection is needed to document their content prior to applying algorithms for electrode localization and intra-cochlear anatomy segmentation. In this work, to determine the presence/absence of inner ears and to accurately localize them in head CTs, we use a volume-to-volume convolutional neural network which can be trained end-to-end to map a raw CT volume to probability maps which indicate inner ear positions. We incorporate a false positive suppression strategy in training and apply a shape-based constraint. We achieve a labeling accuracy of 98.59% and a localization error of 2.45 mm. The localization error is significantly smaller than a random forest-based approach that has been proposed recently to perform the same task.

Growing Challenge for Physicians: Environmental Pollutants

The case of an adolescent patient presenting with multiorgan symptoms demonstrates the importance of taking into account environmental causes as possible etiologies. Physicians must look at the “elephant in the room”, the environment where children live, for possible causes for multi-organ symptomatology. A 13-year-old Hispanic female was treated for multiple complaints since age 9, including fast heart palpitations, nosebleeds, headaches, stomach pains, body spasms, and menometrorrhagia. She was treated in a large metropolitan integrated health system by her pediatrician, a cardiologist, a neurologist, and a gastroenterologist and multiple emergency department visits. She had head CTs, X-rays, and abdominal ultrasounds done, all which were normal. At the same time, she lived 30 feet from AllenCo Energy, the operator of an oil production facility in South Los Angeles that halted operations after neighbors complained that fumes were making them sick. When AllenCo closed in 2013, her headaches, nosebleeds, abdominal pains, body spasms, and heart palpitations stopped. However, she developed asthma and nasal allergies. This case illustrates the impact of environmental pollutants on multiple organ systems. This can confuse diagnosticians to look for organspecific etiologies when the culprits are air-borne toxic emissions of petrochemicals that attack the whole organism.

Incidence, hospital costs and in-hospital mortality rates of surgically treated patients with traumatic cranial epidural hematoma

Abstract Background: In this study, the patients who were operated in two clinics due to traumatic cranial epidural hematoma (EDH) were assessed retrospectively and the factors that increase the costs were tried to be revealed through conducting cost analyses. Methods: The patients who were operated between 2010 and 2016 with the diagnosis of EDH were assessed in terms of age, sex, trauma etiology, Glasgow coma scale (GCS) at admission, the period from trauma to hospital arrival, trauma-related injury in other organs, the localization of hematoma, the size of hematoma, length of stay in the intensive care unit (ICU), length of antibiotherapy administration, number of consultations conducted, total cost of in-hospital treatments of the patients and prognosis. Results: Distribution of GCS were, between 13-15 in 18 (36%) patients, 9-13 in 23 (46%) patients and 3-8 in 9 (18%) patients. The reasons for emergency department admissions were fall from high in 29 (58%) patients, assault in 11 (22%) patients and motor vehicle accident in 10 (20%) patients. The average cost per ICU stay was 2838 $ (range=343-20571 $). The average cost per surgical treatment was 314 $. ICU care was approximately 9 times more expensive than surgical treatment costs. The mortality rate of the study cohort was 14% (7 patients). Conclusion: The prolonged period of stay in the ICU, antibiotherapy and repeat head CTs increase the costs for patients who are surgically treated for EDH.

Is routine head CT indicated in awake stable older patients after a ground level fall?

BackgroundDespite the development of several prediction rules to guide head CT imaging, determining whom to screen for head trauma in the geriatric population after a ground level fall remains controversial. The purpose of this study was to assess the impact of head CT on the management of older adult patients who present with a normal GCS after a ground level fall, and to identify factors that could predict the need for neurosurgical intervention. MethodsA retrospective study was conducted on hemodynamically stable patients >55 years of age with GCS of 15, who presented to a level 1 trauma center after a ground level fall. Radiological reads of head CT scans were reviewed for new findings and clinical documentation was analyzed for evidence of a change in management. Univariate analysis of key demographic and clinical factors was performed to probe for statistically significant differences between patients receiving medical management versus surgical management. ResultsOf 437 patients receiving head CTs, 146 (33.4%) had a positive finding. 95 (21.7%) patients had a change in management; 76 (17.4%) were medication changes and 19 (4.3%) required neurosurgical intervention. Age 85 years and older, and having a neurologic deficit on initial physical examination were found to be significantly associated with the need for neurosurgery. ConclusionThe results of this study confirm that head CT findings often alter clinical management of elderly patients presenting with a GCS of 15 after ground level falls, and should be a part of standard evaluation.

Comparative radiologic identification with standardized single CT images of the paranasal sinuses—Evaluation of inter-rater reliability

The aim of this study was to assess the reproducibility of a standardized image for personal identification (SIPI), used in the comparative analysis of paranasal sinuses, and test the effect of inaccurate reformation of the SIPI on suitability for comparative identification.Five raters with different professional backgrounds independently reformatted SIPIs from ten post-mortem head CTs. Inter-rater, intra-rater agreement as well angular deviations between reformatted SIPI images and reference SIPI images were calculated. Second, raters assessed the suitability of 70 accurately and inaccurately reformatted SIPIs for identification with a 4-point Likert scale. Inter-rater agreement as well as levels of significance regarding image suitability were calculated.Inter-rater agreement regarding reproducibility of SIPI reformation was excellent (inter-rater correlation coefficient (ICC) 0.9995, intra-rater ICC 0.9983). Deviation between the angular dimensions of the reformatted SIPIs and the reference SIPIs was ≤1° in 94% of all 300 measurements. Inter-rater agreement regarding the effect of inaccurate SIPI reformation on suitability for comparative identification was fair (ICC 0.6809). There was no statistically significant difference between raters’ evaluation of image suitability (p=0.9755).This study shows that the standardized image for personal identification can be accurately reformatted by different raters with varying professional backgrounds. In addition, raters agree that inaccurately reformatted SIPIs are still suitable for comparative identification in the majority of cases.

Dual-Energy CT in Enhancing Subdural Effusions that Masquerade as Subdural Hematomas: Diagnosis with Virtual High-Monochromatic (190-keV) Images.

Extravasation of iodinated contrast into subdural space following contrast-enhanced radiographic studies results in hyperdense subdural effusions, which can be mistaken as acute subdural hematomas on follow-up noncontrast head CTs. Our aim was to identify the factors associated with contrast-enhancing subdural effusion, characterize diffusion and washout kinetics of iodine in enhancing subdural effusion, and assess the utility of dual-energy CT in differentiating enhancing subdural effusion from subdural hematoma. We retrospectively analyzed follow-up head dual-energy CT studies in 423 patients with polytrauma who had undergone contrast-enhanced whole-body CT. Twenty-four patients with enhancing subdural effusion composed the study group, and 24 randomly selected patients with subdural hematoma were enrolled in the comparison group. Postprocessing with syngo.via was performed to determine the diffusion and washout kinetics of iodine. The sensitivity and specificity of dual-energy CT for the diagnosis of enhancing subdural effusion were determined with 120-kV, virtual monochromatic energy (190-keV) and virtual noncontrast images. Patients with enhancing subdural effusion were significantly older (mean, 69 years; 95% CI, 60-78 years; P < .001) and had a higher incidence of intracranial hemorrhage (P = .001). Peak iodine concentration in enhancing subdural effusions was reached within the first 8 hours of contrast administration with a mean of 0.98 mg/mL (95% CI, 0.81-1.13 mg/mL), and complete washout was achieved at 38 hours. For the presence of a hyperdense subdural collection on 120-kV images with a loss of hyperattenuation on 190-keV and virtual noncontrast images, when considered as a true-positive for enhancing subdural effusion, the sensitivity was 100% (95% CI, 85.75%-100%) and the specificity was 91.67% (95% CI, 73%-99%). Dual-energy CT has a high sensitivity and specificity in differentiating enhancing subdural effusion from subdural hematoma. Hence, dual-energy CT has a potential to obviate follow-up studies.

Head CT findings at a public hospital in rural Haiti

BackgroundNeuroimaging is often unavailable in low-income countries, creating challenges for precise diagnosis of neurologic disease in individual patients, and impeding acquisition of precise neuroepidemiologic data for program and policy development. MethodsWe analyzed reports from 3614 head CTs performed between July 2013 and January 2016 at Hôpital Universitaire de Mirebalais, a public academic hospital in rural Haiti, extracting patients' age, study indication, and radiologic findings. ResultsThe most common indications for head CT were headache (27%), trauma (19.9%), abnormal neurological exam (12.2%), and stroke (11.3%). The most common categories of neurologic abnormalities were traumatic (31%), vascular (25.8%), and infectious (12%). Of 291 strokes, 64% were ischemic (median age at diagnosis 60.8years, SD 17.4) and 36% were hemorrhagic (median age 52.0, SD 15.5). In patients undergoing head CT for seizures or epilepsy, 17.5% had evidence of neurocysticercosis. In patients with head trauma, 42.6% had intracranial hemorrhage or fracture. Atrophy was noted on 10% of CTs (median age 57.1; SD 23.8), and was characterized as out of proportion to age in 2% (median age 34.1, SD 15.3). ConclusionsMedian age of stroke patients in this rural low-income population is lower than in high-income countries and proportion of stroke due to intracerebral hemorrhage is higher. Neurocysticercosis is present in nearly one fifth of patients with seizures/epilepsy. These findings can inform policies and programs for prevention and treatment of neurologic disease in low-income settings.

Radiologic head CT interpretation errors in pediatric abusive and non-abusive head trauma patients.

Pediatric head trauma, including abusive head trauma, is a significant cause of morbidity and mortality. The purpose of this research was to identify and evaluate radiologic interpretation errors of head CTs performed on abusive and non-abusive pediatric head trauma patients from a community setting referred for a secondary interpretation at a tertiary pediatric hospital. A retrospective search identified 184 patients <5years of age with head CT for known or potential head trauma who had a primary interpretation performed at a referring community hospital by a board-certified radiologist. Two board-certified fellowship-trained neuroradiologists at an academic pediatric hospital independently interpreted the head CTs, compared their interpretations to determine inter-reader discrepancy rates, and resolved discrepancies to establish a consensus second interpretation. The primary interpretation was compared to the consensus second interpretation using the RADPEER™ scoring system to determine the primary interpretation-second interpretation overall and major discrepancy rates. MRI and/or surgical findings were used to validate the primary interpretation or second interpretation when possible. The diagnosis of abusive head trauma was made using clinical and imaging data by a child abuse specialist to separate patients into abusive head trauma and non-abusive head trauma groups. Discrepancy rates were compared for both groups. Lastly, primary interpretations and second interpretations were evaluated for discussion of imaging findings concerning for abusive head trauma. There were statistically significant differences between primary interpretation-second interpretation versus inter-reader overall and major discrepancy rates (28% vs. 6%, P=0.0001; 16% vs. 1%, P=0.0001). There were significant differences in the primary interpretation-second interpretation overall and major discrepancy rates for abusive head trauma patients compared to non-abusive head trauma patients (41% vs 23%, P=0.02; 26% vs. 12%, P=0.03). The most common findings resulting in major radiologic interpretation errors were fractures and subdural hemorrhage. Differences in the age of the patient and the percentage of patients with hemorrhage were statistically significant between the abusive head trauma versus non-abusive head trauma groups, while no statistical difference was identified for skull fractures, ischemia, head CT radiation dose, or presence of multiplanar or 3-D reformatted images. The second interpretation more frequently indicated potential for abusive head trauma compared to the primary interpretation (P=0.0001). MRI and/or surgical findings were in agreement with the second interpretation in 29/29 (100%) of patients with discrepancies. A high incidence of radiologic interpretation errors may occur in pediatric trauma patients at risk for abusive head trauma who are referred from a community hospital. This suggests value for second interpretations of head CTs at a tertiary pediatric hospital for this patient population.

The impact of pregnancy on headache evaluation in the emergency department, a retrospective cohort study.

Headache is one of the most common emergency department complaints with three million visits annually in the USA. This is further complicated with 30% of those emergency visits being for a hypertensive disorder of pregnancy. There is no currently well-established guideline for diagnostic imaging with a common concern being ionizing radiation exposure in pregnancy. The purpose of this study was to assess the difference in imaging studies ordered for pregnant and non-pregnant patients who reported to a tertiary care emergency department with headache. The purpose of this study was to assess the difference in imaging studies ordered for pregnant and non-pregnant patients who reported to a tertiary care emergency department with headache. This retrospective cohort study identified all reproductive age female patients who presented to the emergency department with a chief complaint of "headache." They were then divided into cohorts based on pregnancy status. Rates and types of imaging studies utilized in patient evaluation were then compared. Two thousand seven hundred ninety patients met our criteria for evaluation; 95 were found to be pregnant. Head CTs were ordered significantly less and MRIs were ordered significantly more in the pregnant cohort as compared to the non-pregnant cohort with a P value of <0.0001 and an odds ratio of 4.21 and a P value of 0.0127 and an odds ratio of 0.49, respectively. Our data shows a difference in evaluation for pregnant patients as compared to their non-pregnant cohort. CT should not be considered contraindicated in the pregnant population and the amount of ionizing radiation to the fetus is well within the maximum safe dose, particularly with appropriate shielding. The time difference, cost, fetal exposure risk, and availability of CT compared to MRI should be taken into account when establishing a criterion for diagnostic evaluation. This difference validates the need for further research into a well-established guideline for the emergent evaluation of headache in the ED without special bias placed on pregnancy status.

Abstract WP365: Radiographic Predictors of Prognosis in Intracerebral Hemorrhage: "If It Ain’t Broke, Don’t Fix It"

Background/Purpose: The ICH score (ICHS) is commonly used to predict 30-day mortality in spontaneous ICH. Several investigators have evaluated additional factors in an attempt to refine this score, though none of these modifications have been incorporated into routine practice. We sought to determine whether incorporating additional radiographic features, specifically herniation and/or the degree of midline shift (MLS), improved the performance of the ICH score. Methods: We retrospectively reviewed 180 consecutive ICH patients admitted to a single comprehensive stroke center between September 2014 and November 2015. The outcome of interest was poor prognosis, defined as mRS of 4-6, at time of discharge. Admission head CTs were evaluated by a vascular neurologist to determine whether uncal, tonsillar or subfalcine herniation were present, and to quantify the degree of midline shift. Midline shift was treated as a categorical variable determined by measuring the shift of the septum pellucidum from midline at the level of the basal ganglia. Results: Patients with radiographic herniation present on admission had a much higher odds of poor outcome; however, this measure was specific (98%) but not sensitive (23%). Degree of midline shift performed similarly, with a specificity of 86% and a sensitivity of 36%. In our population, the ICH score was a better predictor of poor outcome than any of the combinations shown in the Table. For each unit increase in ICH score, the odds of a poor outcome increased by a factor of 2.6. Conclusion: Although clinicians often view radiographic evidence of herniation and midline shift as indicators of dire prognosis, incorporation of these features into a modification of the ICH score failed to improve upon the original scale.

Factors associated with adverse outcomes in patients with traumatic intracranial hemorrhage and Glasgow Coma Scale of 15

Patients with mild traumatic brain injury (mTBI) with associated intracranial injury, or complicated mTBI, are at risk of deterioration. Clinical management differs within and between institutions. We conducted an exploratory analysis to determine which of these patients are unlikely to have an adverse outcome and may be future targets for less resource intensive care.This single center retrospective cohort study included patients presenting to the ED with blunt complicated mTBI between January 2001 and December 2010. Patients with a Glasgow coma score (GCS) of 15, an initial head CT with a traumatic abnormality, and a repeat head CT within 24h were eligible. We defined the composite adverse outcome as death within two weeks, neurosurgical procedure within two weeks, hospitalization >48h, and worsened second head CT. Classification and Regression Tree methodology was used to identify factors associated with adverse outcomes.Of 1011 patients with two head CTs performed in a 24-h period, 240 (24%) had complicated mTBI and GCS 15. Of these, 56 (23%) experienced the composite adverse outcome defined above. Age, headache, and subarachnoid hemorrhage, correctly classified 93% of patients with an adverse outcome. No instance of death or neurosurgical procedure was missed.Our analysis highlighted three factors associated with adverse outcomes in persons who have complicated mTBI but a GCS of 15. Absence of these risk factors suggests low risk of adverse outcomes, and may suggest that a patient is safe for discharge home. Additional research is required before utilizing these findings in clinical practice.

Altered Mental Status in ICU Patients: Diagnostic Yield of Noncontrast Head CT for Abnormal and Communicable Findings.

To evaluate the diagnostic yield of noncontrast head CT for acute communicable findings in ICU patients specifically scanned for altered mental status. Retrospective observational cohort study. University Hospital Neuroscience, Medical, and Surgical ICUs. ICU patients with new-onset altered mental status. Noncontrast head CT. Reports on head CTs from two university hospitals performed for the sole indication of altered mental status in ICU patients between July 2011 and June 2013 were reviewed for 1) acute (new or worsening) hemorrhage, 2) mass effect/herniation, 3) infarction, and 4) hydrocephalus. Subgroup analyses of positive findings were performed by 1) ICU group type, 2) age, and 3) race. A total of 2,486 head CTs were performed in 1,357 patients whose age ranged from 14 to 116 years (median, 59; mean, 57.6 ± 16). Acute communicable findings in at least one of four categories were present in 22.8% (566/2,486) of examinations, with hydrocephalus being most common (11.5% [286/2,486]). The frequency of any acute communicable findings in neuroscience, medical, and surgical ICUs was 28.6% (471/1,648), 9.8% (43/440), and 13.1% (52/398), respectively. Neuroscience ICU head CTs had significantly higher rates of acute communicable findings in all categories, except for acute infarction, compared with the other two ICUs (p < 0.001). Acute hydrocephalus (13.6% vs 7.4%; p < 0.001) and mass effect (6.7% vs 4.3%; p = 0.01) were more common in patients less than 65 years. For other acute categories, no significant difference was noted by age. There was no significant difference in the likelihood of a positive examination by race. Almost one in four head CTs in a university ICU patient population performed for primary indication of altered mental status yields abnormal communicable findings. In this patient population, utilization management barriers to examination ordering should be minimized.

Artificial neural networks: Predicting head CT findings in elderly patients presenting with minor head injury after a fall

Objectives: To construct an artificial neural network (ANN) model that can predict the presence of acute CT findings with both high sensitivity and high specificity when applied to the population of patients≥age 65years who have incurred minor head injury after a fall.Methods: An ANN was created in the Python programming language using a population of 514 patients ≥ age 65 years presenting to the ED with minor head injury after a fall. The patient dataset was divided into three parts: 60% for “training”, 20% for “cross validation”, and 20% for “testing”. Sensitivity, specificity, positive and negative predictive values, and accuracy were determined by comparing the model's predictions to the actual correct answers for each patient.Results: On the “cross validation” data, the model attained a sensitivity (“recall”) of 100.00%, specificity of 78.95%, PPV (“precision”) of 78.95%, NPV of 100.00%, and accuracy of 88.24% in detecting the presence of positive head CTs. On the “test” data, the model attained a sensitivity of 97.78%, specificity of 89.47%, PPV of 88.00%, NPV of 98.08%, and accuracy of 93.14% in detecting the presence of positive head CTs.Conclusions: ANNs show great potential for predicting CT findings in the population of patients ≥ 65 years of age presenting with minor head injury after a fall. As a good first step, the ANN showed comparable sensitivity, predictive values, and accuracy, with a much higher specificity than the existing decision rules in clinical usage for predicting head CTs with acute intracranial findings.

Head CBCT vs head MSCT imaging; comparing organ doses and radiation risks for a cohort of orthognathic patients

Introduction In oral and maxillofacial surgery, a preoperative-full-head-scan is required for treatment planning purposes. Orthognathic patients are traditionally referred to radiology departments for a head CT scan. However, state-of-the-art dental-CBCT-scanners, equipped with large detectors and/or stitching and offset-scanning-methods, enable full head image acquisitions. Purpose to calculate organ doses and estimate radiation risks for patients undergoing head-CT and full skull dental-CBCT exams. Materials and methods An EGSnrc-based Monte-Carlo (MC) dosimetry tool was used to calculate organ doses in the reference ICRP-female-voxel-phantom for skull protocols in two dental-CBCT-scanners. Promax-3D-Max (Planmeca, FI) employs a 230 × 260 mm 2 FOV (diameter × height) using a stitching technique and fixed current during rotation. VGi-evo (Newtom, IT) employs a 240 × 190 mm 2 FOV and tube current (TCM) modulation. An anthropomorphic phantom (SK 150, The Phantom Laboratory) was scanned to extract the TCM curve which was then employed to the framework in terms of dose-integral-weighting-factors. CT-Expo v2.2 was used to calculate organ and effective doses for ten adult females, undergone head CTs in an Aquilion One (Toshiba, Japan) and a Somatom Definition Flash (Siemens, DE) scanner. Results The effective dose (ED) for Promax-3D-Max ranges from 85 to 1090 μSv depending on the operation mode (mAs-settings), whereas for VGI-evo the ED was 265 μSv. For head CT the ED ranges from 1.3 to 1.9 mSv. In all cases the highest doses were observed to salivary glands, oral mucosa, ET, brain, thyroid and RBM. Conclusion Dosewise, full-head-dental-CBCT scans demonstrate significantly lower organ doses and lower ED compared to MSCT scanners. Disclosure Nothing to disclose.

Paediatric multi detector computed tomography radiation doses in a dedicated paediatric hospital in Greece

Introduction Multi detector CT (MDCT) X-ray systems provide high quality paediatric imaging. However, the last years, concern has been expressed on radiation exposure to children. Very few surveys depicting paediatric exposure from MDCT s are available. Purpose To shape the status of radiation dose in children from MDCT practice in a dedicated paediatric hospital in Greece. Materials and methods This was a retrospective study in a 160 bed paediatric hospital equipped with a Philips Brilliance 16 CT scanner installed in 2010. Patient data and acquisition parameters were recorded for CT studies of head, abdomen, chest and spine and were divided in three age groups (1–5 years, 5–10 years, 10–15 years). The dosimetric results were reported in terms of volumetric CT dose index (CTDIvol) (mGy), dose length product (DLP) (mGycm), and total DLP for multiphase studies. The results were compared with adult national DRLs and paediatric European published data. Results Data were collected from 97 MDCT examinations and included 39 head CTs, 12 abdomen CTs, 20 chest CTs and 26 spine CTs. Acquisition parameters used were according to age for head CTs and weight-dependent for the other scans. Spiral or axial scan depended on anatomic area and on the radiologist on duty. Multiphase studies accounted for 10% of patient sample, 80% of these in the abdomen region. For the three age groups, CTDIvol, DLP and total DLP average values were significantly lower than adult national DRLs, although they increased with age, and were in accordance with published paediatric European data. Conclusion Initial data showed that use of protocols tailored to patient’s age or weight results in significant dose reduction. Use of standardized CT protocols should be encouraged.

P.067 Incidence of tissue-defined stroke and large vessel occlusion in acute stroke alerts in a non-teaching hospital system

Background: Stroke alerts are used to triage patients with acute neurologic change for rapid imaging evaluation. CTA has been advocated to rapidly triage stroke patients for endovascular therapy. However, the yield of this approach is not well established. We evaluated the stroke alert yield in a non-teaching hospital system. Methods: A retrospective review of radiology reports for stroke alerts using PACS archive. Cases were then followed for 72 hours to determine the types of advanced imaging obtained and the findings of those studies. Results: From January to March 2014, 269 stroke alert head CTs were performed. Subsequent imaging included 128 MRIs (48%), 25 CTAs (9%) and 2 angiograms (0.7%). There were 58 (22%) tissue-defined strokes and 16 were non-lacunar (6% stroke alerts). 61% of stroke alert head CTs were negative or reported microvascular change. Other findings included large vessel occlusion (5%), intracranial stenosis (1.5%), extracranial stenosis(1.5 %), intracranial hemorrhage (9%) and masses (13%). Conclusions: Most stroke alerts were negative for tissue-defined stroke. Based on this data, universal use of CTA in the ER to triage patients with acute neurologic symptoms may not be appropriate. An updated triage system to facilitate endovascular rescue is being analyzed for changes to advanced imaging utilization and yield.

P015: Implementing the Canadian CT Head Rule in a community emergency department

Introduction: The Canadian CT Head Rule (‘the rule’) is widely used across the country and its use is specifically recommended by Choosing Wisely Canada. Studies in Canadian hospitals have shown appropriate declines in CT scans when decision tools have been made readily available and useable at the point of care. Research into the implementation of the Canadian CT Head Rule in particular has shown that barriers to its use include an inability to accurately recall each criteria and forgetting to attempt to apply the rule altogether. In an attempt to provide our clinicians with effective access to the rule, we modified CT requisitions and order procedures to facilitate the use of the rule for every head CT in our emergency department (ED). Methods: A quality improvement (QI) approach was used to pilot, implement, and evaluate the modified CT requisition at our hospital. Several Plan-Do-Study-Act cycles involving stakeholders in the hospital resulted in iterative changes to the requisition leading to the implemented version. The new requisition required physicians to indicate which rules or exclusion criteria were met and this was made mandatory for all head CTs ordered. Demographic data was collected on all patients presenting to the ED on age, gender, CTAS level, disposition, and length of stay. Data on which exclusion criteria were appropriate, the rules met leading to CT scans, whether each requisition was used appropriately, and whether there was a significant injury found was collected for each patient receiving a head CT after implementation. Results: In our primary outcome (% of ED visits receiving a head CT), preliminary results have demonstrated a relative reduction in head CT ordering of 10.9%. Our study at completion is powered to detect a ~10% relative change in ordering behaviour, and a Chi square of the data to date yields a P-value of 0.0147. There are no significant differences in visit volume or any of the demographics collected to date. Final results including analysis are anticipated in March, 2016. Conclusion: Preliminary results on this simple, no-cost intervention are very promising. The reduction in head CTs ordered suggests that with mandated access to an easy-to-use, well validated decision tool, ED physicians have been able to confidently defer scans that have a very low risk of having any significant injury present, reducing cost, radiation exposure, and perhaps time in department.

Understanding and Mitigating Unexpected Artifacts in Head CTs: A Practical Experience

Understanding and Mitigating Unexpected Artifacts in Head CTs: A Practical Experience

Reduction in radiation doses from paediatric CT scans in Great Britain.

Although CT scans provide great medical benefits, concerns have been raised about the magnitude of possible associated cancer risk, particularly in children who are more sensitive to radiation than adults. Unnecessary high doses during CT examinations can also be delivered to children, if the scan parameters are not adjusted for patient age and size. We conducted the first survey to directly assess the trends in CT scan parameters and doses for paediatric CT scans performed in Great Britain between 1978 and 2008. We retrieved 1073 CT film sets from 36 hospitals. The patients were 0-19 years old, and CT scans were conducted between 1978 and 2008. We extracted scan parameters from each film including tube current-time product [milliampere seconds (mAs)], tube potential [peak kilovoltage (kVp)] and manufacturer and model of the CT scanner. We estimated the mean mAs for head and trunk (chest and abdomen/pelvis) scans, according to patient age (0-4, 5-9, 10-14 and 15-19 years) and scan year (<1990, 1990-1994, 1995-1999 and ≥2000), and then derived the volumetric CT dose index and estimated organ doses. For head CT scans, mean mAs decreased by about 47% on average from before 1990 to after 2000, with the decrease starting around 1990. The mean mAs for head CTs did not vary with age before 1990, whereas slightly lower mAs values were used for younger patients after 1990. Similar declines in mAs were observed for trunk CTs: a 46% decline on an average from before 1990 to after 2000. Although mean mAs for trunk CTs did not vary with age before 1990, the value varied markedly by age, from 63 mAs for age 0-4 years compared with 315 mAs for those aged >15 years after 2000. No material changes in kVp were found. Estimated brain-absorbed dose from head CT scans decreased from 62 mGy before 1990 to approximately 30 mGy after 2000. For chest CT scans, the lung dose to children aged 0-4 years decreased from 28 mGy before 1990 to 4 mGy after 2000. We found that mAs for head and trunk CTs was approximately halved starting around 1990, and age-specific mAs was generally used for paediatric scans after this date. These changes will have substantially reduced the radiation exposure to children from CT scans in Great Britain. The study shows that mAs and major organ doses for paediatric CT scans in Great Britain began to decrease around 1990.

How to Reduce Head CT Orders in Children with Hydrocephalus Using the Lean Six Sigma Methodology: Experience at a Major Quaternary Care Academic Children's Center.

Lean Six Sigma methodology is increasingly used to drive improvement in patient safety, quality of care, and cost-effectiveness throughout the US health care delivery system. To demonstrate our value as specialists, radiologists can combine lean methodologies along with imaging expertise to optimize imaging elements-of-care pathways. In this article, we describe a Lean Six Sigma project with the goal of reducing the relative use of pediatric head CTs in our population of patients with hydrocephalus by 50% within 6 months. We applied a Lean Six Sigma methodology using a multidisciplinary team at a quaternary care academic children's center. The existing baseline imaging practice for hydrocephalus was outlined in a Kaizen session, and potential interventions were discussed. An improved radiation-free workflow with ultrafast MR imaging was created. Baseline data were collected for 3 months by using the departmental radiology information system. Data collection continued postintervention and during the control phase (each for 3 months). The percentage of neuroimaging per technique (head CT, head ultrasound, ultrafast brain MR imaging, and routine brain MR imaging) was recorded during each phase. The improved workflow resulted in a 75% relative reduction in the percentage of hydrocephalus imaging performed by CT between the pre- and postintervention/control phases (Z-test, P = .0001). Our lean interventions in the pediatric hydrocephalus care pathway resulted in a significant reduction in head CT orders and increased use of ultrafast brain MR imaging.