Use Of CT Research Articles

Prevalence of serious injuries in low risk trauma patients

ObjectivesComputed tomography (CT) utilization is widespread in contemporary Emergency Departments (EDs). CT overuse leads to radiation exposure, contrast toxicity, overdiagnosis, and incidental findings. This study explores the prevalence of clinically significant injuries in patients identified as low-risk trauma patients (LRTPs) using newly created criteria that account for the patient's age, trauma mechanism, assessability (which relies on level of consciousness, intoxication, and neurologic deficits), vital signs and other evidence of hypoperfusion, bleeding risk, and past medical history. MethodsThis was a 6-month retrospective chart review of all LRTPs presenting to a level 1 trauma center in Queens, New York. Data abstraction was performed independently by two abstractors and discrepancies adjudicated by the senior author. Patients were identified using the hospital trauma registry and two reports, created by the researchers, identifying selected chief complaints and discharge diagnoses. Results750 patients were identified of which 352 (46.93%) received one or more CT scans. There were a total of 790 CT scans ordered, of which 731 (92.53%) were negative for acute injury. There were 13 clinically significant injuries of which only one (0.13%) required immediate intervention. There were no mortalities in this LRTP group. ConclusionThe prevalence of clinically significant injuries in this population is very low and injuries requiring immediate intervention are even lower. CT utilization in LRTPs should be guided by an explicit consideration of benefit and harm for each patient.

Emergency Trauma Providers as Equal Partners: From “Proof of Concept” to “Outcome Parity”

Enmeshment of emergency trauma providers (ETPs) into the United States health-care fabric resulted in the establishment of a formalized surgical critical care fellowship and certification for emergency medicine trainees. The aim of this study was to compare trauma outcomes for surgery-trained providers (STPs) and ETPs at our institution, hypothesizing patient outcome equivalency. We performed an institutional review board-exempt institutional registry review (January 1, 2004 to August 1, 2018), comparing 74 STPs and 6 ETPs. Comparator variables included all-cause mortality, all-cause morbidity, CT imaging studies per provider, time in ED (min), hospital/ICU lengths of stay, ICU admissions, and functional outcomes on discharge. Statistical comparisons included chi-square test for categorical data and analysis of covariance for continuous data (adjustments made for patient age, Injury Severity Score, and trauma mechanism; all P < 0.20). Statistical significance was set at P < 0.05, with an equivalence study design. A total of 33,577 trauma resuscitations were reviewed (32,299 STP-led and 1,278 ETP-led). Except for patient age (STP 50.2 ± 25.9 vs ETP 54.9 ± 25.3 years), Injury Severity Score (8.47 ± 8.14 vs 9.22 ± 8.40), and ICU admissions (16.1% vs 18.8%), we noted no significant intergroup differences. ETPs' performance was equivalent to that of STPs for all primary comparator variables (mortality, morbidity, CT utilization, time in the ED, lengths of stay, and functional outcomes). Incorporation of ETPs into our trauma center resulted in outcome parity between ETPs and STPs, while simultaneously expanding the expertise and experiential diversity within our multidisciplinary team. This study provides support for further incorporation of ETPs as equal partners across the growing network of United States regional trauma centers.

Quality of CT Imaging of Periocular Metallic Foreign Bodies Using Artifact Reduction Software.

CT is the standard of care for assessment of ocular and orbital trauma; however, artifacts from metallic foreign bodies can limit the utility of CT. The authors hypothesize that implementation of metal artifact reduction techniques can improve image quality and diagnostic confidence for a diverse group of interpreters. A case series of ten subjects with retained periocular metallic foreign bodies imaged with CT were identified retrospectively from a large urban trauma center. Postacquisition images were processed with an iterative-based metal streak artifact reduction software. The severity of the metal streak artifact was assessed by clinicians including radiologists (4), ophthalmologists (4), and oculoplastic specialists (3) using a numeric scale to grade images on seven clinically relevant criteria. Each image was also analyzed to measure the size of the artifact and degree of streaking. Overall confidence in diagnosis and severity of metallic streak was improved with metallic artifact reduction (p < 0.001, Wilcoxon signed-rank test). Similarly, confidence in assessing specific features-including extra-ocular muscle, optic nerve, globe rupture, orbital fracture and identification of foreign bodies-was improved after metallic artifact reduction (p < 0.001, Wilcoxon signed-rank test). The standard deviation of pixel intensity for a path surrounding the foreign body as well as the area of the streak artifact decreased in the metallic artifact reduction-processed images (p < 0.001, paired t test). Metal artifact reduction in CT has potential benefits in improving image quality and reader confidence for periocular trauma cases in real-world settings.

Awareness of relative CT utilization among peers is not associated with changes in imaging requests among emergency department providers in a large county hospital.

The purpose of this quality improvement initiative was to study the effect of providing scorecards to emergency department providers to assess its effect on changes in utilization. CT of the abdomen and pelvis, CT angiogram of the chest for pulmonaryembolism, and CT of the head were targeted due to ordering variability, cost, and radiation exposure. The utilization rate for each provider was assessed for emergency department providers. Following this, providers were given scorecards regarding their utilization as well as their relative utilization compared with each other. Utilization was then monitored following the intervention to assess the effect of the scorecard on ordering practices. No significant effect on the utilization of these 3 exams was found after the scorecard intervention. Providing scorecards to make emergency department providers aware of their relative utilization does not significantly alter ordering behavior. Incentive-based systems may be required in order to lessen overutilization of these 3 commonly ordered radiology procedures in the emergency department.

Role of pelvic CT during surveillance of patients with resected biliary tract cancer

The aim of the study was to identify the frequency of isolated pelvic metastasis with the goal of determining the utility of pelvic CT as a surveillance strategy in patients with resected biliary tract cancer (BTC). Study eligibility criteria included patients 18years or older with BTC who underwent R0 or R1 surgical resection at University of Michigan between 2004 and 2018, with a minimum 6-month disease-free surveillance period. CT and MRI reports were independently graded by two radiologists as positive (organ metastasis, peritoneal carcinomatosis, or enlarged lymph nodes), equivocal (borderline lymph nodes or non-nodular ascites), or negative (absence of or benign findings) in the abdomen and pelvis separately. A 3rd blinded radiologist reviewed all positive and equivocal scans. Clinic notes were reviewed to identify new or worsening signs and symptoms that would warrant an earlier pelvic surveillance scan. A 95% binomial proportion confidence interval was used to find the probability of isolated pelvic metastasis. BTC were anatomically classified as extra-hepatic (distal and hilar) cholangiocarcinoma (38; 25%), intra-hepatic cholangiocarcinoma (57; 38%), and gallbladder cancer (56; 37%). 151 patients met eligibility criteria, of which 123 (81%) had no pelvic metastasis, 51 (34%) had localized upper abdominal metastasis, and 23 (15%) had concomitant abdominal and pelvic metastasis. Median follow-up time was 19.2months. One (0%) subject with resected BTC (intra-hepatic) developed isolated osseous pelvic metastasis during surveillance (95% CI 0.004-0.1; p = 0.0003). 3 (2%) subjects developed isolated simple ascites (equivocal grade) without concurrent upper abdominal metastasis. Isolated pelvic metastasis is a rare occurrence during surveillance in patients with resected BTCs, and therefore, follow-up pelvic CT in absence of specific symptoms may be unnecessary.

Appropriateness of pediatric CT utilization in clinical practice

Background: Cerebral collateral circulation is necessary to maintain cerebral blood flow and penumbra when arterial insufficiency occurred. Only a few studies about collateral status on development of malignant middle cerebral artery infarction (mMCAi) have been documented. Objective: To determine whether collateral status evaluated by single phase computed tomographic angiography (CTA) help prediction of mMCAi in patients with large arterial occlusion whom not received endovascular treatment. Material and Methods: We retrospectively reviewed patients with acute ischemic stroke in anterior circulation in our institute during January 2015 to December 2015. We analyzed clinical data, baseline National Institutes of Health Stroke Scale (NIHSS), Alberta Stroke Program Early CT Score (ASPECTS) on baseline nonenhanced computed tomography of the brain (NECT brain), and CTA collateral status. Malignant MCA infarction was defined according to clinical criteria. Results: Thirty-five patients were included. Mean age was 68.8±15.56 years. Mean baseline NIHSS and baseline ASPECTS were 17(±5) and 6(±3), respectively. All patients received intravenous thrombolysis. CTA collateral status and baseline NECT ASPECTS significantly correlated with development of mMCAi (P-value = 0.007 and 0.001). Only baseline NECT ASPECTS was an independent predictive factor for mMCAi (OR 0.63, 95%CI 0.46-0.86, P-value =0.004). Patients with baseline NECT ASPECTS ≤ 7 were more likely develop mMCAi (OR 14.29 95%CI 1.57-129.94, P-value 0.018). Conclusion: In acute stroke patients with proximal MCA or ICA occlusion received intravenous thrombolysis alone, baseline NECT ASPECTS and CTA collateral status were significantly correlate with development of mMCAi. However, only baseline ASPECTS ≤ 7 was an independent predictor for mMCAi.

Appropriateness of pediatric CT utilization in clinical practice

Background: Justification of imaging investigations is important, particularly in pediatrics underwent investigation using a relatively higher radiation such as CT, due to the higher radiation sensitivity of children.&#x0D; Objective: To assess the difference of viewpoints between pediatric physicians and pediatric radiologists on the appropriateness of pediatric CT utilization in a tertiary-care university hospital with limited MR capacity.&#x0D; Methods: Pediatric medical records of head CT, chest CT, and abdominal CT were retrospectively reviewed in consecutive date of the examination until having 100 head CTs and 100 body CTs with complete clinical and imaging information. The physicians and the radiologists were asked to suggest the imaging modality of choice for each patient according to the given data, regardless of the hospital’s limitation. If the suggested modality of choice was not CT, the CT request would be considered as “inappropriate”. They additionally scored the CT appropriateness, firstly using individual judgement, and secondly using the ACR Appropriateness Criteria. Both scoring methods used the same rating scale from 1 to 9; score 1-3 was considered “inappropriate”.&#x0D; Results: From the viewpoint of the physicians and radiologists, the number of inappropriate CT request was 20% and 54% according to “the modality of choice”, 2.5% and 17% according to “individual judgement”, 12% and 22% according to the “ACR Appropriateness Criteria”. The main difference was not from no indication for imaging but from the selected modality of imaging. The radiologists suggested 52% of head CTs and 64% of abdominal CTs could have been replaced by MRI if available.&#x0D; Conclusion: There are ten-percent disagreement on appropriateness of pediatric CT request between physicians and the radiologists when using the same guidelines and considering the hospital limitation.

Diagnostic Value of CT in Detecting Peripheral Zone Prostate Cancer.

OBJECTIVE. The purpose of this study was to identify the sensitivity of contrast-enhanced CT in detecting high-grade prostate adenocarcinoma. MATERIALS AND METHODS. A retrospective analysis included 100 patients with prostate cancer proven by biopsy between January 2010 and December 2017 who underwent staging CT of the abdomen and pelvis within 3 months of diagnosis. The control subjects were 100 randomly selected aged-matched male outpatients with no known history of malignancy who underwent contrast-enhanced CT of the abdomen and pelvis in the same time period as the patients with cancer. Two readers, blinded to both groups, independently assessed the likelihood of prostate cancer on the basis of the CT finding of focal abnormally increased peripheral enhancement in the prostate. Binary classification of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) was used to assess the diagnostic utility of CT versus the reference standard of transrectal ultrasound-guided biopsy. RESULTS. Eighty-three of 100 patients with biopsy-proven prostate cancer and 92 of 100 control subjects were correctly identified (sensitivity, 0.83; specificity, 0.92; PPV, 0.91; NPV, 0.84). There was no significant difference in diagnostic accuracy among subjects with different Gleason scores. Interrater agreement on both the cancer and control patients was 0.76 as assessed by Cohen kappa statistic. CONCLUSION. Incidental detection of a focal area of increased enhancement in the periphery of the prostate at contrast-enhanced CT may represent a clinically significant cancer and deserves further workup with prostate-specific antigen measurement and correlation with clinical risk factors for prostate cancer.

What a difference a delay makes! CT urogram: a pictorial essay.

The aim of this pictorial essay is to demonstrate several cases where the diagnosis would have been difficult or impossible without the excretory phase image of CT urography. A brief discussion of CT urography technique and dose reduction is followed by several cases illustrating the utility of CT urography. CT urography has become the primary imaging modality for evaluation of hematuria, as well as in the staging and surveillance of urinary tract malignancies. CT urography includes a non-contrast phase and contrast-enhanced nephrographic and excretory (delayed) phases. While the three phases add to the diagnostic ability of CT urography, it also adds potential patient radiation dose. Several techniques including automatic exposure control, iterative reconstruction algorithms, higher noise tolerance, and split-bolus have been successfully used to mitigate dose. The excretory phase is timed such that the excreted contrast opacifies the urinary collecting system and allows for greater detection of filling defects or other abnormalities. Sixteen cases illustrating the utility of excretory phase imaging are reviewed. Excretory phase imaging of CT urography can be an essential tool for detecting and appropriately characterizing urinary tract malignancies, renal papillary and medullary abnormalities, CT radiolucent stones, congenital abnormalities, certain chronic inflammatory conditions, and perinephric collections.

Subglottic stenosis and endobronchial disease in granulomatosis with polyangiitis.

To describe tracheobronchial disease in patients with granulomatosis with polyangiitis (GPA) and evaluate the utility of dynamic expiratory CT to detect large-airway disease. Demographic and clinical features associated with the presence of subglottic stenosis (SGS) or endobronchial involvement were assessed in a multicentre, observational cohort of patients with GPA. A subset of patients with GPA from a single-centre cohort underwent dynamic chest CT to evaluate the airways. Among 962 patients with GPA, SGS and endobronchial disease were identified in 95 (10%) and 59 (6%) patients, respectively. Patients with SGS were more likely to be female (72% vs 53%, P < 0.01), younger at time of diagnosis (36 vs 49 years, P < 0.01), and have saddle-nose deformities (28% vs 10%, P < 0.01), but were less likely to have renal involvement (39% vs 62%, P < 0.01). Patients with endobronchial disease were more likely to be PR3-ANCA positive (85% vs 66%, P < 0.01), with more ENT involvement (97% vs 77%, P < 0.01) and less renal involvement (42% vs 62%, P < 0.01). Disease activity in patients with large-airway disease was commonly isolated to the subglottis/upper airway (57%) or bronchi (32%). Seven of 23 patients screened by dynamic chest CT had large-airway pathology, including four patients with chronic, unexplained cough, discovered to have tracheobronchomalacia. SGS and endobronchial disease occur in 10% and 6% of patients with GPA, respectively, and may occur without disease activity in other organs. Dynamic expiratory chest CT is a potential non-invasive screening test for large-airway involvement in GPA.

Utility of CT and MRI in assessment of mandibular involvement in oral cavity cancer.

ObjectiveOral cavity squamous cell carcinoma (SCC) may present with early invasion of mandibular bone. Preoperative planning of surgery is essential considering patient's postoperative quality of life. Our purpose was to evaluate the efficacy of computer tomography scan (CT) and magnetic resonance imaging (MRI) in detecting mandibular bone involvement in oral SCC.MethodsA retrospective study was conducted on 98 patients with SCC of floor of mouth, lower alveolus and retromolar trigone operated on with curative intent. Preoperative CT and MRI scans were re-reviewed by a consultant radiologist and original histology slides were re-reviewed by 3 pathologists.ResultsForty-five patients were included in the final study. Combined CT and MRI had a sensitivity of 100% and a specificity of 72%.ConclusionThe results suggest that combined CT and MRI have diagnostic utility in detecting mandibular invasion by oral cancer, but with a significant false positive rate.

Clinical utility of virtual noncalcium dual-energy CT in imaging of the pelvis and hip.

Dual-energy virtual noncalcium images are increasingly used to identify marrow edema which accompanies bony pelvic injuries and marrow pathology obscured by cancellous bone. We present a clinical perspective of our experience using virtual noncalcium images in the work up of pelvic osseous pathology.

The diagnostic performance of dual energy CT for diagnosing gout: a systematic literature review and meta-analysis.

This study aimed to assess the utility of dual energy CT (DECT) for diagnosing gout. A systematic literature search was performed in PubMed, EMBASE and Cochrane Library. Studies evaluating the utility of DECT for diagnosing gout were included. Reference standards were detection of monosodium urate crystals at SF assessment or a validated set of criteria. The methodological quality of studies was evaluated according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 criteria. Data from person-based and joint-/localization-based evaluations were pooled separately, and subgroup analyses for disease stage/duration and reference standard were performed. Ten studies were included; in person-based evaluations, the pooled (95% CI) sensitivity and specificity were 0.81 (0.77, 0.86) and 0.91 (0.85, 0.95), respectively. In joint-based evaluations, they were 0.83 (0.79, 0.86) and 0.88 (0.83, 0.92), respectively. At short disease duration (⩽6 weeks), the pooled (95% CI) sensitivity and specificity at the joint level were 0.55 (0.46, 0.64) and 0.89 (0.84, 0.94), respectively. DECT has a high diagnostic accuracy in established gout, but its diagnostic sensitivity is low in subjects with recent onset gout.

State of the art: utility of multi-energy CT in the evaluation of pulmonary vasculature.

Multi-energy computed tomography (MECT) refers to acquisition of CT data at multiple energy levels (typically two levels) using different technologies such as dual-source, dual-layer and rapid tube voltage switching. In addition to conventional/routine diagnostic images, MECT provides additional image sets including iodine maps, virtual non-contrast images, and virtual monoenergetic images. These image sets provide tissue/material characterization beyond what is possible with conventional CT. MECT provides invaluable additional information in the evaluation of pulmonary vasculature, primarily by the assessment of pulmonary perfusion. This functional information provided by the MECT is complementary to the morphological information from a conventional CT angiography. In this article, we review the technique and applications of MECT in the evaluation of pulmonary vasculature.

LO87: Impact of an evidence-based clinical pathway for suspected renal colic in low-risk patients with previous nephrolithiasis on CT utilization and emergency department throughput

Background: Choosing Wisely (CW) recommends patients under age 50 with uncomplicated, recurrent renal colic do not require CT scans. Despite this, CT use has risen dramatically in the past two decades, resulting in unnecessary radiation, cost and prolonged length of stay (LOS). Additionally, a common alternative – formal ultrasound (US) – is not always available. Returning for US can add 10 hours to LOS. We introduced a clinical management pathway (CMP) for low-risk patients with renal colic utilizing point-of-care ultrasound (POCUS) and evaluated its impact on emergency department (ED) CT rates and LOS. Aim Statement: By April 2019, we aim to reduce CT utilization by 50% and time from physician initial assessment (PIA) to discharge by 1 hour for patients under age 50 presenting to Sunnybrook ED with uncomplicated, recurrent renal colic. Measures &amp;amp; Design: The primary intervention was a CMP developed collaboratively with local urologists. The CMP uses POCUS to assess for hydronephrosis (HN) as a marker of nephrolithiasis. Patients with HN receive follow-up in urology clinic without confirmatory imaging. Patients without HN proceed to usual care. An Ishikawa diagram helped identify barriers to success. Subsequent PDSA cycles included the introduction of reference cards, POCUS workshops and online modules. Outcome measures were ED CT utilization and PIA to discharge times. Process measures were referrals to urology clinic and proportion of patients receiving XR, US and no imaging. Balancing measures were urology CT utilization, alternate diagnoses and return ED visits. Data was plotted on a run chart. Evaluation/Results: Data collection is ongoing and will conclude by April 2019. Interim data shows patients enrolled in the CMP have a reduction in mean PIA-to-discharge time of 173 minutes. Fidelity – specifically, the willingness of ED physicians to use POCUS compared to the ease of ordering CTs – is the biggest challenge to success. Discussion/Impact: This study addresses the feasibility of CW recommendations and utilizes POCUS as a tool for recurrent renal colic. Collaboration with Urology will provide insight into the CMP's sustainability and downstream impact. Reduction of unnecessary CTs will lead to improved patient safety and reduced costs. Decreased PIA-to-discharge times will reduce overcrowding, shorten wait times and improve access to imaging for other patients. Finally, this project may encourage use of POCUS for low-risk patients with renal colic.

LO69: A retrospective cohort study on the impact of point-of-care ultrasound on radiologic imaging in patients presenting to the emergency department with suspected uncomplicated renal colic

Introduction: The number of CT scans prescribed in the Emergency department (ED) for suspected renal colic has increased over recent years without an associated improvement in patient-centred outcomes. We assessed whether Point-of-Care Ultrasound (PoCUS) decreases the use of formal radiologic imaging. Methods: We completed a retrospective cohort study on consecutive patients 18 years of age and older presenting to the ED with suspected uncomplicated renal colic in a tertiary care centre in Québec in 2016. Exclusion criteria included: previous urologic intervention, solitary kidney, dialysis, fever, pyuria, acute kidney injury, pregnancy, suspicion of a serious alternative diagnosis or persistent symptoms despite analgesia. We compared the proportion (95%CI) of formal radiologic imaging performed (Ultrasound or CT) in patients who had PoCUS in the ED vs. those who did not. Two-tailed Fisher exact test (α = 0.05) and odds ratios (95%CI) calculated from multivariate logistic regression models adjusted for age, gender, Charlson Index and previous renal colic were used to compare the two groups. The reliability of data collection was evaluated with a kappa score (95%CI). Results: 169 patients with uncomplicated renal colic were included. There was no difference between the groups in terms of age, gender, Charlson Index, or previous renal colic. The PoCUS level of training and the doctor's education level was significantly higher in the PoCUS group. There was a non-significant trend towards less formal imaging in patients of the PoCUS group 65/88 (73.9% [63.4-82.7%]) vs. the non-PoCUS group 69/81 (85.2% [75.6-92.1%]), p = 0.087. After adjustment for confounders, the patients not evaluated with PoCUS were more likely to have formal imaging with a significant odds ratio of 2.41 [1.05-5.56]). Among patients who underwent a CT, incidentalomas were found in 16.5% and only 2.0% demonstrated significant findings leading to changes in ED management, such as an alternative diagnosis, need for admission, or an urgent urological intervention. Inter-observer agreement was excellent between assessers with a kappa score of 0.88 [0.66-1.00]. Conclusion: ED patients with uncomplicated renal colic who are investigated with PoCUS tend to have fewer formal imaging test. When CT scans were performed, incidentalomas were found in 16.5% and ED management changed only 2.0% of the time. PoCUS appears to be a useful tool for decreasing CT utilisation in this low-risk ED population.

Computed tomography attenuation value for the characterization of pleural effusions in dogs: A cross-sectional study in 58 dogs

CT attenuation value can help to differentiate exudate from transudate in people. The aim of this cross-sectional study was to assess the utility of CT in characterizing pleural effusions based on attenuation values in a population of dogs having CT and diagnostic thoracentesis within 48 h of each other. The CT attenuation values were determined using four circular, same size, regions of interest (ROIs) placed on the same CT slice with the greatest quantity of fluid. Values of each ROI were recorded and the mean of the four ROIs mean values (mean of the means) was calculated and considered as the CT attenuation value of that patient. The final population included 23 proper inflammatory exudates, 15 chylous effusions, 12 hemorrhagic effusions and 8 transudates.The median of ‘mean of the means’ values were: exudate 19.22 HU (8.23 to 37.66 HU); chylous effusion 10.26 HU (−0.90 to 15.37); hemorrhagic effusion 31.65 HU (18.10 to 54.97), and transudate 11.20 HU, (−2.52 to 16.59). CT accurately differentiated hemorrhagic from chylous effusion (AUC 1.0, P < 0.0001) and hemorrhagic effusion from transudate (AUC 1.0, P < 0.0001); CT-values allowed good accuracy in distinguishing exudates from transudates [AUC 0.87 (95%, CI: 0.74–1.0; P < 0.0001)]. HU attenuation values did not accurately differentiate between transudates and chylous effusion. A cutoff value of 34.68 HU (sensitivity of 96% and specificity of 95%) discriminated between exudates and hemorrhagic effusions. CT-value <12.15 HU had a sensitivity of 94% and specificity of 78% for identify transudate or chylous effusion.

Simulating Dual-Energy X-Ray Absorptiometry in CT Using Deep-Learning Segmentation Cascade

PurposeOsteoporosis is an underdiagnosed condition despite effective screening modalities. Dual-energy x-ray absorptiometry (DEXA) screening, although recommended in clinical guidelines, remains markedly underutilized. In contrast to DEXA, CT utilization is high and presents a valuable data source for opportunistic osteoporosis screening. The purpose of this study was to describe a method to simulate lumbar DEXA scores from routinely acquired CT studies using a machine-learning algorithm. MethodsBetween January 2010 and September 2014, 610 CT studies of the abdomen and pelvis were used to develop spinal column and L1 to L4 multiclass segmentation. DEXA simulation training and validation used 1,843 pairs of CT studies accompanied by DEXA results obtained within a 6-month interval from the same individual. Machine learning–based regression was used to determine correlation between calculated grade (on the basis of vertebrae L1-L4) and DEXA t score. ResultsAnalysis of the t score equivalent, generated by the algorithm, revealed true positives in 1,144 patients, false positives in 92 patients, true negatives in 245 patients, and false negatives in 212 patients, resulting in an accuracy of 82%. Sensitivity for the detection of osteoporosis or osteopenia was 84.4% (95% confidence interval, 82.3%-86.2%), and specificity was 72.7% (95% confidence interval, 67.7%-77.2%). ConclusionsThe presented algorithm can identify osteoporosis and osteopenia with a high degree of accuracy (82%) and a small proportion of false positives. Efforts to cull greater information using machine-learning algorithms from pre-existing data have the potential to have a marked impact on population health efforts such as bone mineral density screening for osteoporosis, in which gaps in screening currently exist.

Advanced diagnostic imaging utilization during emergency department visits in the United States: A predictive modeling study for emergency department triage.

BackgroundEmergency department (ED) crowding is associated with negative health outcomes, patient dissatisfaction, and longer length of stay (LOS). The addition of advanced diagnostic imaging (ADI), namely CT, ultrasound (U/S), and MRI to ED encounter work up is a predictor of longer length of stay. Earlier and improved prediction of patients’ need for advanced imaging may improve overall ED efficiency. The aim of the study was to detect the association between ADI utilization and the structured and unstructured information immediately available during ED triage, and to develop and validate models to predict utilization of ADI during an ED encounter.MethodsWe used the United States National Hospital Ambulatory Medical Care Survey data from 2009 to 2014 to examine which sociodemographic and clinical factors immediately available at ED triage were associated with the utilization of CT, U/S, MRI, and multiple ADI during a patient’s ED stay. We used natural language processing (NLP) topic modeling to incorporate free-text reason for visit data available at time of ED triage in addition to other structured patient data to predict the use of ADI using multivariable logistic regression models.ResultsAmong the 139,150 adult ED visits from a national probability sample of hospitals across the U.S, 21.9% resulted in ADI use, including 16.8% who had a CT, 3.6% who had an ultrasound, 0.4% who had an MRI, and 1.2% of the population who had multiple types of ADI. The c-statistic of the predictive models was greater than or equal to 0.78 for all imaging outcomes, and the addition of text-based reason for visit information improved the accuracy of all predictive models.ConclusionsPatient information immediately available during ED triage can accurately predict the eventual use of advanced diagnostic imaging during an ED visit. Such models have the potential to be incorporated into the ED triage workflow in order to more rapidly identify patients who may require advanced imaging during their ED stay and assist with medical decision-making.

Large hospital variation in the utilization of Post-procedural CT to detect pulmonary embolism/Deep Vein Thrombosis in Patients Undergoing Total Knee or Hip Replacement Surgery: Japanese Nationwide Diagnosis Procedure Combination Database Study.

The purpose of the study was to investigate variation in the use of in-hospital CT for venous thromboembolism (VTE) detection after total knee or hip replacement (TKR/THR) among surgical patients, using a nationwide Japanese in-hospital administrative database. This retrospective study using a national administrative database (4/2012-3/2013) extracted patients who underwent TKR/THR surgeries at hospitals meeting the annual case-volume threshold of ≥ 30. Hospitals were categorized into three equally sized groups by frequency of postoperative CT use (low, middle, and high CT use group) to compare baseline patient-level and hospital-level characteristics. To further investigate between-hospital variation in CT usage, we fitted a hierarchical logistic regression model including hospital-specific random intercepts and fixed patient- and hospital-level effects. The intra class correlation coefficient was used to measure the amount of variability in CT use attributable to between-hospital variation. A total of 39,127 patients discharged from 447 hospitals met the inclusion criteria. The median hospital stay was 25 days (interquartile range, 20 - 32) and 7,599 (19.4%) patients underwent CT for VTE. CT utilization varied greatly among the hospitals; the crude frequency ranged from 0 to 100 % (median, 7.3 %; interquartile range, 1.8 - 18.3 %). After adjustment for known hospital- and patient-level factors related to CT use, 47 % of the variation in CT use remained attributable to the behavior of individual hospitals. We observed large inter hospital variability in the utilization of post-procedure CT for VTE detection in this Japanese TKR/THR cohort, suggesting that CT utilization is not optimized across the nation. We observed significant variability in the utilization of post-procedure CT for VTE detection among inpatients who underwent TKR/THR surgeries in a large sample of Japanese hospitals. The large variation suggests that CT utilization is not optimized across the nation, and that there may be potential overutilization of the technology in the highest CT use hospitals.