Use Of CT Research Articles

Utility of C-Arm CT in Detection Hepatocellular Carcinoma during Trans Arterial Chemoembolization

Abstract Background Transcatheter arterial chemoembolization is one of the effective therapeutic options for hepatocellular carcinoma (HCC). Ultraselective chemoembolization is an alternative approach to improve local control, and is associated with a reduced incidence of adverse effects. Objective It was to evaluate the sensitivity of cone beam computed tomography (CBCT) in detecting HCC tumors and their feeding vessels during transarterial chemoembolization (TACE). Patients and Methods All patients were suspected of having or confirmed to have HCC on the basis of clinical history, underlying liver disease and/or viral infection, the diagnosis of HCC was made by imaging findings. Between January 2016 and January 2018, Dyna CT was retrospectively used in 19 consecutive patients with HCC tumor with HCC tumor. Results The detectability of the tumor with DSA obtained at the common, proper, right, or left hepatic artery (i.e., nonselective DSA) and cone-beam CT was compared as taking pre imaging as a gold standard. Tumor stain and feeding branches were evaluated. The detectability of the tumor-feeding branch with non-selective DSA and Dyna CT HA images was compared. Conclusion Tumor detectability on cone-beam CT was significantly greater than on non-selective. Cone beam HA taking pre imaging as a gold standard was (94.4%) and its specificity (71.6%) with accuracy (76.97%). The sensitivity of DSA in detection of additional tumor as taking the pre imaging (CT/MRI) as a gold standard was (88.9%) and its specificity (84.5%) with accuracy (85.53%). Cone-beam CT has satisfactory ability to detect tumors; the detectability of tumor-feeding branches with Dyna CT was significantly higher than that with nonselective DSA (P less than 0.001). We believe the technical success rates of ultraselective transcatheter arterial chemoembolization may be improved by chemoembolization guidance software that uses cone-beam CT technology.

Abstract No. 572 National trends in inpatient intracranial arteriovenous malformation imaging and interventions from 2006 to 2014

To evaluate national trends in intracranial arteriovenous malformations (AVM) imaging utilization and interventions in US inpatient hospital stays. Using 2006-2014 data from the Nationwide Inpatient Sample (NIS), we identified inpatient stays with a primary diagnosis of intracranial AVM. Changes in the utilization of non-invasive neuroimaging (both CT and MRI), catheter-based digital subtraction angiography (DSA), and interventions (open surgical, endovascular and radiosurgery) were identified and independent predictors were evaluated using logistic regression. Between 2006 and 2014, there were a weighted total of 39,255 inpatient stays with for intracranial AVM (mean age, 40; 49% male; 59% white; 54% with private insurance). Utilization of head CT decreased from 5.2% of encounters in 2006 to 3.1% in 2014; brain MRI decreased from 7.4% to 4.1%. In contrast, DSA increased from 54.6% to 59.3% of stays. Open surgical repair increased from 27.8% to 33.6% of stays, while endovascular therapy and radiosurgery decreased from 40.2% to 33.3% and 1.0% to 0.6%, respectively. Significant independent predictors for utilization of non-invasive imaging, DSA, endovascular and surgical interventions are reported in Table 1. Over time, inpatient utilization of head CT and brain MRI in the setting of intracranial AVM has decreased, suggesting increased use of preadmission emergency department and outpatient imaging. Although endovascular treatment was the most common intervention in 2006, its use in recent years has declined as open surgery has become more frequent.Table 1Independent predictors of inpatient imaging and interventions for intracranial AVM.Imaging [OR(95% CI)]DSAEndovascularSurgeryAge ≤ 501.0 (0.8-1.3)0.9 (0.8-1.1)0.9 (0.9-1.1)1.4 (1.0-1.8)Male1.0 (0.8-1.2)1.2 (1.1-1.4)1.0 (0.9-1.2)1.1 (0.9-1.3)Elective admission0.5 (0.3-0.7)2.1 (1.7-2.7)4.5 (3.5-5.7)3.9 (3.0-5.1)Non-weekend admission0.9 (0.7-1.3)1.2 (0.9-1.5)1.9 (1.3-2.7)1.5 (1.0-2.2)Length of stay >6 days2.0 (1.5-2.7)1.8 (1.5-2.2)1.2 (0.9-1.6)6.4 (5.2-7.9) Open table in a new tab

3:27 PM Abstract No. 25 Iodinated coating of decayed Y-90 microspheres to improve radiopacity with cone-beam computed tomography

To envelope SIR-Spheres (SS) with a chitosan/iodine shell in order to display greater contrast enhancement compared to non-coated control SS with cone-beam CT. Centrifuge 1000μL of radioactively inactive SS at 10,000 RPM for 10 minutes and remove excess water. Combine 7mL of Omnipaque (Op) solution (2% acetic acid, 3 mg/mL chitosan) with the pelleted SS and place on a shaker plate for 30 minutes. While shaking, add 7mL of 10 mg/mL TPP (in 100% Op) dropwise over 1 minute, and continue to shake for 30 minutes. Wash the sample by centrifuging at 14,000 RPM for 10 min then resuspending in diH2O. Continue these spin/wash cycles for a total of 3 washes. Remove 25μL of sample and place on a scanning electron microscope (SEM) stub for SEM and Elemental Dispersive X-Ray Spectroscopy (EDX) analysis. Transfer the remaining washed sample to a 1.5mL centrifuge tube for cone-beam CT assessment. In order to add additional coatings, the above steps were repeated. Cone beam CT imaging showed an increase in contrast resolution of double and triple coated SS when compared to control SS. Better contrast resolution was seen with triple coated SS when compared to double coated SS. SEM images of control SS, singe coated SS, double coated SS, and triple coated SS showed progressive layering of chitosan/Op coatings with each additional coating attempt. EDX elemental analysis results show a stepwise increase in iodine content when looking at control SS, single coated SS, double coated SS, and triple coated SS, with average iodine contents of 0%, 33.4%, 42.8%, and 63.0% respectively. The ability to intraoperatively assess SIRT dosage delivery would allow localization of treated and untreated regions. With this knowledge, other interventions can be applied to ensure a more efficacious treatment plan. In this study we were able to apply significant amounts of radiopaque iodine to the surface of SS. With the utilization of SEM, EDX, and cone-beam CT, we confirmed that we (1) successfully enveloped SS in crosslinked chitosan, (2) successfully entrapped iodinated molecules within this chitosan shell, and (3) successfully demonstrated visibility with cone-beam CT of SS with the iodinated shell.

Utilization of CT imaging in minor pediatric head, thoracic, and abdominal trauma in the United States

BackgroundLiberal use of CT scanning in children with blunt trauma risks unnecessary radiation exposure and cost. Recent literature questions the utility of whole-body CT in stable children without clinical evidence of significant injury, but this is often done based on injury mechanism. The purpose of this study is to quantify the utilization of CT scans of the head, chest, abdomen, and pelvis based on injury severity in these body regions and to assess the impact of American College of Surgeons (ACS) pediatric trauma center designation on CT utilization in children with minor or no injuries. MethodsWe queried the National Trauma Databank for 2014, 2015, and 2016 to identify all patients 14 years and younger. Using Abbreviated Injury Scale (AIS) score as a proxy for injury severity, we analyzed the number of head, thoracic, and abdominal CT scans done for patients at low levels of injury severity (AIS 0–2) in each of these body regions and according to trauma center level designation (ACS I, II, III, standalone pediatric I or II, and non ACS accredited). ResultsOf 257,661 children who were entered into the database for any reason, overall CT utilization was 20% for head, 5% for the chest and 9% for the abdomen and pelvis. Children with no injuries or minimal injury to the head were scanned 7% and 46% of the time, respectively, for the chest 3% and 13% and for the abdomen 6% and 30%. For all body regions and all levels of injury severity, level 1 stand-alone pediatric centers displayed significantly lower CT utilization rates than others. ConclusionCT scan rates for children with minimal or no injuries to the head, chest, abdomen and pelvis are significant. Level 1 stand-alone pediatric trauma centers are least likely to perform these studies. Widespread education and acceptance of clinical guidelines for imaging in stable patients throughout trauma systems could alleviate this disparity. Level of evidenceLevel III retrospective comparative study

Evaluation of lumbar intervertebral disc degeneration using dual energy CT virtual non-calcium imaging

PurposeTo clarify the utility of dual energy CT (DECT) virtual non-calcium (VNCa) imaging for investigating lumbar intervertebral disc degeneration. MethodFifty-three patients who underwent both DECT and MR imaging were retrospectively reviewed. Midsagittal T2-weighted imaging findings of all discs were classified based on modified Pfirrmann grade (mPG). Quantitative evaluation of VNCa maps was achieved by setting volumes of interest on each disc. We compared VNCa CT values with mPG using Spearman’s rank correlation and one-way ANOVA. VNCa imaging findings of each disc were classified by two neuroradiologists into one of three categories based on the attenuation of nucleus pulposus (NP) compared to that of annulus fibrosus (AF) or muscle. The relationship between the visual categories for each rater and mPGs was analyzed by chi-square test. Statistical significance was established at P < 0.05. ResultsAmong the included 171 lumbar discs, significant positive correlation was found between VNCa CT values for NP and mPGs (R2 = 0.574, P < 0.05), whereas no significant correlation was found between those for AF and mPGs (R2= –0.015, P = 0.846). Mean VNCa CT values for NP were significantly different among each mPG (P < 0.05 for each), except between grades 3 and 4 (P = 0.111). Mean VNCa CT values for AF were not significantly different among each mPG (P = 0.160–1.000). Statistically significant difference was observed among the visual categories for VNCa maps and mPGs in each rater (P < 0.05 for both). ConclusionsVNCa imaging acquired by a single DECT scan and post-processing has potential as an imaging biomarker of lumbar intervertebral disc degeneration.

Predicting Response to Neoadjuvant Chemotherapy Using 18F FDG PET-CT in Patients with Locally Advanced Breast Cancer.

Objective:The study was aimed to find the utility of 18F FDG PET CT in assessing response to neoadjuvant chemotherapy (NACT) in female patients with locally advanced breast cancer (LABC). Methods:All willing women with biopsy proven LABC, following clinical evaluation underwent baseline 18F FDG PET CT along with mammosonograpy and contrast enhanced computerized chest radiography (CECT). The response was assessed clinically before each cycle of chemotherapy using RECIST criteria. Those who were progressing clinically were offered alternate chemotherapy or radiation or surgery. Clinical responders were re-evaluated with 18F FDG PET CT, mammosonogram and CT chest before surgery. The pathological response as assed with residual cancer burden score was used as gold standard. Results:Of the 30 women eligible, 26 women underwent repeat evaluation and surgery. The mean age was 49 years, 16 women were postmenopausal and 15 tumors were receptor positive. On final histopathology 15 % had completer response and 46 % were non responders. Using a cut off value of 50% of the baseline SUVmax, PET-CT had sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 64%, 75%, 75%, 65%, and 69%, respectively in differentiating pathological responders from non-responders. Conclusion:18F FDG PET-CT predicted the response with greater accuracy than CT or clinical examination. Hence it can be used to identify non responders early in the course and alternate treatment can be offered to patients.

The Diagnostic Utility of Prone Position Chest CT for the Evaluation of Esophageal Cancer.

The aim of this study was to assess the potential of a prone chest CT for the evaluation of esophageal cancer, as compared with a routine supine chest CT. 69 patients (67±18 years old) with pathologically confirmed esophageal cancers underwent MDCT in the supine and prone positions. The supine CT was performed first, followed by the prone position. Localization and staging of individual esophageal lesions on both the prone and supine CTs were assessed by two thoracic radiologists, using a scoring system that consisted of three confidence scales, and the results were correlated with the endoscopic and surgical findings. The mean confidence score for the detection of esophageal cancer was higher in the prone position (2.58±0.74) than that in the supine position (2.42±0.83) with statistical significance (p=0.002). The mean confidence score for predicting local invasion in the selected patients (n=18) who underwent esophagectomy was also higher in the prone position (2.39±0.85) than that in the supine position (2.06±0.73) with statistical significance (p=0.01). In 10 of 11 cases that showed definitive determination for periesophageal infiltration or adjacent organ invasion on the prone CT (score 3), the corresponding findings were also observed in the post-operative evaluations. In conclusion, prone chest CT for evaluating esophageal cancer could have advantages in regards to the localization of esophageal cancer and predicting local invasion compared to that of routine supine CT and can improve the diagnostic accuracy of chest CTs.

Cardiac Angiosarcoma Heralded by Recurrent Hemorrhagic Pericardial Effusions–Utility of MRI and CT

Cardiac Angiosarcoma Heralded by Recurrent Hemorrhagic Pericardial Effusions–Utility of MRI and CT

Neuroimaging for Migraine: The American Headache Society Systematic Review and Evidence-Based Guideline.

To provide updated evidence-based recommendations about when to obtain neuroimaging in patients with migraine. Articles were included in the systematic review if they studied adults 18 and over who were seeking outpatient treatment for any type of migraine and who underwent neuroimaging (MRI or CT). Medline, Web of Science, and Cochrane Clinical Trials were searched from 1973 to August 31, 2018. Reviewers identified studies, extracted data, and assessed the quality of the evidence in duplicate. We assessed study quality using the Newcastle-Ottawa Scale. The initial search yielded 2269 publications. Twenty three articles met inclusion criteria and were included in the final review. The majority of studies were retrospective cohort or cross-sectional studies. There were 4 prospective observational studies. Ten studies evaluated the utility of CT only, 9 MRI only, and 4 evaluated both. Common abnormalities included chronic ischemia or atrophy with CT and MRI scanning, and non-specific white matter lesions with MRI. Clinically meaningful abnormalities requiring intervention were relatively rare. Clinically significant neuroimaging abnormalities in patients with headaches consistent with migraine without atypical features or red flags appeared no more common than in the general population. There is no necessity to do neuroimaging in patients with headaches consistent with migraine who have a normal neurologic examination, and there are no atypical features or red flags present. Grade A Neuroimaging may be considered for presumed migraine for the following reasons: unusual, prolonged, or persistent aura; increasing frequency, severity, or change in clinical features, first or worst migraine, migraine with brainstem aura, migraine with confusion, migraine with motor manifestations (hemiplegic migraine), late-life migraine accompaniments, aura without headache, side-locked headache, and posttraumatic headache. Most of these are consensus based with little or no literature support. Grade C.

18 Utilisation of Head CT to Determine Rates of Intracranial Injury Following Inpatient Falls in the Medical Department, Hospital Kuala Lumpur (HKL)

Abstract Introduction Inpatient falls are associated with serious and life–threatening injuries in 4-6% of cases1. This includes Intracranial Injury (ICI). Imaging of the Head is required to detect and manage patients with head injury2; however there are no specific guidelines to facilitate utilisation of Head CT after Inpatient Falls. Objective The goal of this study is to review the utilisation of Head CT to determine rates of intracranial injury (ICI) following inpatient falls. Methodology This is a retrospective study of all patients admitted to the Medical Department, HKL in year 2017 who sustained an inpatient fall. The data was obtained from the database of the Falls Team HKL and review of medical notes. Results 152 patients, with an average age of (61.65±15.51) years were included in this study. Of these 94 (61.8%) were male, 85 (55.9%) were ≥ 65 years. 45 (29.6%) patients had a Head CT after inpatient fall. Median time to request for Head CT was 130 (IQR 30–582.50) minutes from the time of fall. Head CT was more likely in patients with Direct impact to head during fall (Adj.OR;4.71(95%CI 1.39 – 15.85). Fifty-seven (37.5%) patients sustained Direct impact to head during fall, however only 32/57(71.1%) had a Head CT as inpatient. Patients who had Direct impact to head during fall, were more likely to develop Giddiness (Adj.OR;5.96(95%CI 1.94-18.30) and Hematoma (Adj.OR;6.186(95%CI 1.59 – 24.03) after fall. Intracranial injury (ICI) was identified in 5/45 (11.1%) patients who underwent a Head CT. Patients with (ICI) had an average age of (74.00 ±7.906) years. All 5 patients were reviewed by the Neurosurgical team. Of these, 1/5 (20%) patient died during hospitalisation and 1/5 (20%) patient was discharged in a terminally ill condition. Conclusion Intracranial injury (ICI) was identified in 5/45 (11.1%) patients who underwent a Head CT and they were more likely to be ≥ 65years. Head CT was more likely in patients with Direct impact to head, headache, hematoma and confusion after inpatient fall.

Utility of Cardiac CT for Evaluation of Mechanical Complications of Myocardial Infarction

Utility of Cardiac CT for Evaluation of Mechanical Complications of Myocardial Infarction

Duodenal emergencies: utility of multidetector CT with 2D multiplanar reconstructions for challenging but critical diagnoses.

Duodenal pathology is an infrequent cause of acute abdominal pain for which patients present to the emergency department. Critical pathology on multidetector CT (MDCT) may be overlooked if the radiologist does not carefully evaluate the duodenum as part of the search pattern. Optimal MDCT protocols include intravenous contrast with multiplanar reconstructions (MPRs). A variety of etiologies ranging from infection to malignancy can involve the duodenum, for which interrogation with MPRs is most helpful given the anatomy and complex relationship with surrounding structures. The purpose of this review article is to highlight the importance of CT acquisition with multiplanar reconstructions and review the spectrum of emergent duodenal pathology, with the goal of ensuring accurate and timely diagnosis to best guide patient management.

Utility of dual-energy CT for predicting the vascularity of meningiomas

PurposeDual-energy computed tomography (DECT) can provide iodine, electron density (ED), and effective atomic number Z (Zeff) maps, facilitating the identification of tissue types. We investigated whether DECT parameters can predict the vascularity of meningiomas. MethodWe acquired DECT and perfusion CT (PCT) images in 24 patients with histologically diagnosed meningioma. Regions of interest (ROIs) were placed at the tumor in iodine, ED, and Zeff maps derived from DECT and in a blood volume (BV) map derived from PCT. To normalize these parameters' values, we divided them by the values of contralateral normal-appearing white matter, i.e., the relative (r)ED, rZeff, and rBV. The vascular density of the tumor specimens was immunohistochemically analyzed by calculating the von Willebrand factor-positive vessel wall. We calculated Pearson's correlation coefficients to determine the correlation with PCT/DECT parameters and an immunohistopathological index. ResultsContrast rZeff (r = 0.7020, p = 0.0001) and iodine (r = 0.5814, p = 0.0029) both had positive correlations with rBV derived from PCT. The rED values were negatively correlated with the rBV values (r = −0.4735, p = 0.0194), and the vascular density results confirmed positive correlations with rBV (r = 0.6909, p = 0.0002) and contrast rZeff (r = 0.4982, p = 0.0132) and a negative correlation with rED (r = −0.4265, p = 0.0377). Regarding the radiation exposure, the mean estimated volume CT dose index (CTDIvol) of DECT was 33.1 ± 1.72 mGy, much lower than that of PCT (103.3 ± 4.65 mGy). ConclusionsDECT predicted vascular density with lower radiation exposure compared to PCT. DECT could potentially replace PCT for evaluating the vascularity of meningiomas.

Utility of pre-procedural CT and abdominal radiography before percutaneous radiologic gastrostomy placement.

To evaluate the utility of pre-procedural CT and abdominal radiography before percutaneous radiologic gastrostomy tube placement. A retrospective review of gastrostomy tube placements was conducted at a tertiary care radiology department. During the studied period, all percutaneous radiologic G-tube placements (PRG) at the institution required a pre-procedural abdominal CT. Whether the CT was interpreted to have an adequate window for PRG was recorded. The same patients with pre-procedural abdominal radiographs were also identified and retrospectively reviewed for the presence of satisfactory anatomy for PRG. Outcomes of tube placements were reviewed. 126 PRG requests were identified, all with abdominal CTs. 110 also had an abdominal radiograph. An adequate window for PRG was present in 83% of patients by CT and 73% by radiography. Of patients in whom it was attempted, 94% underwent successful PRG with a 7.4% minor complication rate. Of those refused for PRG based on CT, 9% had successful percutaneous endoscopic G-tube placement, resulting in a sensitivity of 98%. 97% of patients with satisfactory anatomy by radiograph underwent successful PRG. Of those with no window, 66% had a window by CT, and 94% in whom it was attempted had successful PRG placement. This resulted in a sensitivity of 77% for radiography. Concordance between CT and radiography was 73%. Pre-procedural CT interpretation is highly predictive of successful and uncomplicated PRG. Abdominal radiography also predicts successful PRG, but with a lower accuracy, limiting its utility as a pre-procedural exam.

Incidence and Implication of Coronary Artery Calcium on Non-gated Chest Computed Tomography Scans: A Large Observational Cohort.

Introduction Coronary artery calcification (CAC) scoring is typically performed utilizing non-contrast, electrocardiogram- (ECG) gated CT and offers an estimation of cardiovascular (CV) prognosis and risk stratification beyond previously established cardiac risk factors. Coronary calcification can also be assessed during non-gated chest CT, which is significant given the recent recommendations for lung cancer screening by low-dose CT.MethodsWe retrospectively reviewed 4,953 non-contrast chest CT scans in a single, closed referral tertiary military treatment facility over an 18-month period. Baseline CV outcomes to include myocardial infarction (MI), cerebral vascular accidents (CVA), revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG), death, or a composite of all major adverse cardiac events (MACE), and baseline CV risk factors were abstracted from an electronic medical record (EMR) review.ResultsCAC was seen in 3,119 (63%) patients while 1,834 (27%) were without CAC. All traditional CV risk factors were more commonly observed in patients with CAC. Unadjusted odds of composite MACE, death, MI, coronary revascularization, and CVA between presence and absence of CAC were as follows: 3.55 [95% confidence interval (CI): 2.60-4.86, p: <0.0001]; 2.98 (95% CI: 2.02-4.40, p: <0.0001); 24.42 (95% CI: 3.36-177.6, p: <0.0001); 5.64 (95% CI: 2.58-12.32, p: <0.0001); and 2.32 (95% CI: 1.19-4.50, p: 0.0104), respectively. However, after adjusting for baseline risk factors, CAC on non-gated CT was associated only with an increased observed rate of MI (aOR: 38.1, 95% CI: 4.57-318.2, p: <0.0001) and revascularization (aOR: 5.58, 95% CI: 2.22-14.0, p; 0.0003).ConclusionsFindings of CAC on non-gated chest CT may help to recognize patients who are at increased risk of MI and revascularization. Given the expected increase in chest CT utilization among former smokers for lung cancer screening, observed CAC should be reported to ordering providers in order to identify patients at increased risk of these important outcomes.

Clinical utility of dual-energy CT used as an add-on to 18F FDG PET/CT in the preoperative staging of resectable NSCLC with suspected single osteolytic metastases

ObjectiveTo determine the clinical value of 18F-FDG-PET/CT and dual-energy virtual noncalcium CT to detect and identify single osteolytic metastases (SOM) in participants with non-small cell lung cancer (NSCLC). Materials and MethodsForty-two participants (mean age, 63.5 years ± 10.1; range, 41–81 years) with suspected SOM diagnosed by whole-body 18F-FDG-PET/CT underwent non-enhanced dual-energy CT. All images were visually and quantitatively evaluated by two nuclear medicine physicians (R1 and R2) and two radiologists (R3 and R4) independently. The results of visual and quantitative analysis of 18F-FDG-PET/CT and dual-energy CT were compared with pathological results. ResultsIn the visual analysis, the specificity and positive predictive value of dual-energy CT for reader 1 and reader 2 is larger than the corresponding figures of18F-FDG-PET/CT for reader 3 and reader 4 (94.1% each vs 82.4%/76.5%; 95.2%/95.0% vs 88.9%/86.2%). The sensitivity and negative predictive value of dual-energy CT is relatively lower than the number of 18F-FDG-PET/CT for readers (80.0%/76.0% vs 96.0%/100.0%; 76.2%/72.7% vs 93.3%/100.0%, respectively). ROI-based analysis of SUVmax on PET/CT images and CT numbers on VNCa images showed a significant difference between metastases and non-metastases (P < 0.001 each). ConclusionsPre-surgical evaluation by combination of whole-body 18F-FDG-PET/CT and dual-energy CT could improve the classification of SOM and may further guide the surgical decision-making in participants with NSCLC.

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

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 of all adult ED visits in our institution for five consecutive years (1/2013-12/2017). Retrieved variables included the following: demographics, mode of arrival to the ED, comorbidities, home medications, structured and unstructured chief complaints, vital signs, pain scale score, emergency severity index, ED wing assignment, documentation of previous ED visits, hospitalizations and CTs, and current visit non-contrast head CT usage. A machine learning gradient boosting model was trained on data from the years 2013-2016 and tested on data from 2017. Area under the curve (AUC) was used as metrics. Single-variable AUCs were also determined. Youden's index evaluated optimal sensitivity and specificity of the models. The final cohort included 595,561 ED visits. Non-contrast head CT usage rate was 11.8%. Each visit was coded into an input vector of 171 variables. Single-variable analysis showed that chief complaint had the best single predictive analysis (AUC = 0.87). The best model showed an AUC of 0.93 (95% CI 0.931-0.936) for predicting non-contrast head CT usage at triage level. The model had a sensitivity of 88.1% and specificity of 85.7% for non-contrast head CT utilization. The developed model can identify patients that need to undergo head CT exam already in the ED triage level and by that allow faster diagnosis and treatment.

153 Freestanding vs. Hospital-Based Emergency Department Utilization and Throughput Metrics Across the United States

Freestanding emergency departments (EDs) have grown significantly in the past decade and represent approximately 10% of EDs in the United States. The objective of this study was to compare throughput metrics and utilization measures for freestanding ED versus hospital-based EDs of similar volume and geographic region. ED Benchmarking Alliance data for freestanding EDs (FSED) and hospital-based EDs (HBED) for 2017 was utilized. Our explanatory variable was facility type (freestanding versus hospital-based ED). Outcomes between FSED and HBED were compared. Normally distributed variables are presented as mean and standard deviation and p-values were obtained from t-tests. Non-normally distributed variables are presented as median and interquartile range and p-values from Wilcoxon rank sum tests. Outcomes were weighted based on the proportion of ED volume per facility. Outcome measures between FSED and HBED were compared both nationally and at the state level. Overall, the FSED performed better in most outcomes at the National level as compared to HBED although there are some measures that the HBED performed better than the FSED. Median length of stay (104.2 vs. 140.0), length of stay for treated and released patients (98.6 vs. 122.9), door to bed (4 vs 8), door to doctor (11 vs 16), percentage of patients admitted through the ED (4 vs 11) and percentage of patients leaving the ED without being seen (LWBS) (0.9 vs 1.5), were significantly lower in the FSED as compared to HBED, (P<0.0001). On the other hand, length of stay for admitted patients (265.9 vs 241.8), and median boarding time (96.8 vs. 71.3) were significantly lower in HBED when compared to FSED (P<0.0001). X-ray utilization per 100 patients was 24.6 at the FSED and 37.7 at the HBED (P<0.001). CT utilization per 100 patients was 10.76 at the FSED and 16.02 at the HBED (P<0.0001). EKG utilization per 100 patients was 10.32 at the FSED and 19.06 at the HBED (P<0.0001). At the state level, median length of stay, door to doctor, door to bed and percentage of LWBS were lower in FSEDs than in HBEDs while length of stay to admission, length of stay to discharge, median boarding as well as other variables varied by state. FEDs compared to HBEDs of similar size and geographic location across the country have faster length of stay, door to doctor, door to bed and lower LWBS compared to HBEDs and lower CT, EKG and x-ray utilization.

Correlation of Single Photon Emission Computed Tomography Results with Clinical and Intraoperative Findings in the Painful Total Ankle Replacement

Category:Ankle ArthritisIntroduction/Purpose:Determining the etiology of pain after total ankle replacement (TAR) often serves as a diagnostic dilemma for many surgeons, particularly in the setting of normal appearing radiographs. Single photon emission computed tomography (SPECT CT) has been identified as a potentially useful tool to evaluate pain after TAR. However, prior research has been limited by a lack of comparison to clinical findings as well as comparison to other imaging modalities.Our study aims to add to the current understanding of the role of SPECT CT as a diagnostic tool in TAR. It is our hypothesis that SPECT CT would be predictive of clinical and intraoperative findings in patients with pain after TAR.Methods:A retrospective review was undertaken of SPECT CT imaging performed at our institution for the evaluation of painful TAR from January 2014 to November 2018. There were 35 patients identified during this time period who underwent SPECT CT to evaluate pain after TAR. The average length of time from index surgery to SPECT CT was 17.2 months. Of this cohort, 18 patients also had an MRI during the same time frame and images were available for comparison.Findings on the imaging studies were compared to clinical findings as documented in the medical record, as well as intraoperative findings at the time of revision surgery when one was performed. SPECT CT results, as well as MRI results when available, were evaluated for their consistency with documented clinical and intraoperative findings.Results:Of the 35 patients, 91.4% (32/35) had SPECT CT results that were consistent with clinical findings. Amongst the diagnoses for which SPECT CT was useful in this cohort, loosening (12/32) and impingement (10/32) were most common. Other diagnoses included malalignment (4/32), cyst formation (2/32), subtalar arthritis (2/32), and infection (2/32).In our cohort, 25 patients underwent revision surgery, and SPECT CT imaging was consistent with ultimate intraoperative findings in 24 (96.0%) cases. Procedures performed were revision for aseptic loosening (11/25), gutter debridement (5/25), revision for malalignment (2/25), hindfoot reconstruction (2/25), implant removal for infection (2/25), cyst grafting, subtalar arthrodesis, and conversion to ankle arthrodesis.In the 18 patients who also underwent MRI, these results were consistent with clinical findings 38.9% (7/18) of the time.Conclusion:In this cohort, there was a high consistency between SPECT CT results and documented clinical diagnoses. Additionally, in those patients who ultimately underwent revision surgery, SPECT CT demonstrated high consistency with intraoperative findings. When compared to MRI, SPECT CT proved more useful in helping to establish a diagnosis for pain after TAR in our cohort. Our series serves to highlight the utility of SPECT CT as an additional tool in evaluating the painful TAR. Further investigation into the interpretation of SPECT CT after TAR, including changes in physiologic postoperative uptake that occur over time, is warranted.

Role of Cycle Threshold in Clostridioides difficile Polymerase Chain Reaction Testing as a Predictor of Clinical Outcomes in Patients With Inflammatory Bowel Disease

Abstract Background Distinguishing Clostridioides difficile infection from colonization is challenging in patients with Inflammatory Bowel Disease (IBD). Cycle threshold (Ct), the cutoff for PCR positivity, has been investigated in non-IBD patients. Methods Patients with positive C. difficile PCR (25 IBD, 51 non-IBD) were identified retrospectively. Fifteen-day outcomes were assessed. Results Ct correlated with diarrheal days in non-IBD (P = 0.048), but not IBD patients (P = 0.769). IBD patients had shorter LOS and less severe infection, but more diarrheal days (P &amp;lt; 0.05). Conclusions IBD patients had a milder course but Ct results were not significant. Larger studies are needed to clarify utility of Ct in IBD.