Official Proceedings - AIUM

American Institute of Ultrasound in Medicine Proceedings J Ultrasound Med 32(suppl):S1–S134, 2013Methods—We retrospectively reviewed the results of all abdominalultrasound examinations in patients who also had liver biopsiesfrom 2006 to 2010 to determine the positive predictive value of ultrasoundfor the detection of NAFLD in our department. We scored theseverity of fatty liver on ultrasound from 0 to 3: 0, normal liver echo texture;1, increased liver echogenicity relative to kidney; 2, increased liverechogenicity that obscures echogenic periportal fat; and 3, increased liverechogenicity that obscures visualization of deep liver parenchyma. Wecompared the ultrasound score to histology.Results—A total of 170 patients were included in the study.The sensitivity of ultrasound for detection of NAFLD in this patient populationwas 91% (86%–95%), specificity 75% (35%–97%), and positivepredictive value 99% (95%–100%). There was, however, no correlationbetween the sonographic severity of NAFLD and the presence of NASHor fibrosis.Conclusions—Ultrasound has a high predictive value for thediagnosis of NAFLD in patients who undergo liver biopsy. However,the severity of fatty liver based on the sonographic appearance does notcorrelate with the histologic severity of fatty liver disease and does not differentiatebetween bland steatosis and NASH.1537502 Shear Wave Velocity Discrimination of Inflamed FibroticBowel Segments in a Crohn’s Disease Animal ModelJonathan Dillman, Ryan Stidham, Peter Higgins, DavidMoons, Laura Johnson, Jonathan Rubin* University ofMichigan, Ann Arbor, Michigan USAObjectives—To determine if acoustic radiation force impulse(ARFI) elastography-derived bowel wall shear wave velocity (SWV) candistinguish inflamed from fibrotic intestine in a Crohn’s disease animalmodel.Methods—An acute inflammation Crohn’s disease model wasproduced by treating Lewis rats with a single trinitrobenzenesulfonic acid(TNBS) enema, with imaging performed 2 days later (n = 8). Colonic fibrosisin Lewis rats was achieved by administering repeated TNBS enemasover 4 weeks, with imaging performed 7 days later to allow resolutionof acute inflammation (n = 8). Nine transcutaneous bowel wall SWVmeasurements (Virtual Touch IQ/Acuson S3000 ultrasound system;Siemens Medical Solutions USA) were obtained from the rectosigmoidcolon region in all rats without and with applied strain. Mean bowel wallSWVs without and with applied strain were compared between animalcohorts. Receiver operating characteristic curves were created to assessdiagnostic performance. Three rats were excluded from analysis due todemise.Results—Mean bowel wall SWVs were significantly higherfor fibrotic vs acute inflammation cohort rats at 0% (3.42 ± 1.12 vs 2.30± 0.51 m/s; P = .047) and 30% (6.27 ± 2.20 vs 3.61 ± 0.87 m/s; P = .021)applied strain. Both acute inflammation and fibrotic cohort rats demonstratedlinear increases in mean SWVs with increasing applied strain, withno overlap in the 95% confidence intervals. The mean slopes (0.054 ±0.029 vs 0.114 ± 0.044; P = .016) and y-intercepts (2.07 ± 0.32 vs 3.33 ±1.14; P = .023) were significantly different. The c-statistic of SWV fordifferentiating fibrotic from inflamed bowel was 0.764.Conclusions—Bowel wall SWV distinguishes fibrotic from inflamedintestine in a Crohn’s disease animal model. This finding couldhave a major impact in the diagnosis and treatment of strictures in Crohn’sdisease where fibrotic strictures can only be treated surgically, while inflammatorystrictures are treated medically. In addition, the linearity ofthe slopes in the shear wave vs applied strain model would remove preloadingeffects up to at least 30% applied strains, which could removevariations due to different operator preloads.S671540986 Volumetric Blood Flow Assessment in Transjugular IntrahepaticPortosystemic Shunt Revision Using 3-DimensionalUltrasoundStephen Pinter, 1 * Jonathan Rubin, 1 Oliver Kripfgans, 1 PaulaNovelli, 1 Mario Vargas-Vila, 2 Anne Hall, 3 J. Brian Fowlkes 11Radiology, 2 Medical School, University of Michigan, Ann Arbor,Michigan USA; 3 GE Healthcare, Wauwatosa, Wisconsin USAObjectives—Transjugular intrahepatic portosystemic shunts(TIPS) are prone to thrombosis and stenosis over time and must be monitoredto identify cases requiring flow restoration. The purpose of thisstudy was to evaluate shunt patency using 3D ultrasound volumetricblood flow in patients undergoing shunt revision. Shunt volume flow isintended to provide a more sensitive and robust alternative to standardpulsed wave Doppler shunt velocity or invasive portosystemic pressuregradient measurements.Methods—Ten patients were recruited. A GE LOGIQ 9 ultrasoundsystem (4D3CL, 2.0–5.0 MHz) was used to acquire multivolumerespiratory-gated 3D color Doppler data sets for each patient to assessshunt volume flow before and after the revision procedure. Volume flowwas computed offline by surface integration of Doppler-measured velocityvectors in a c-surface (lateral-elevational plane) positioned at the colorflow focal depth, which ranged from 8.0 to 11.5 cm. Doppler poweryielded pixel-by-pixel correction factors for partial volume integration.Volume flow was compared to routine measurements of pre and post pressuregradient across the shunt measured by catheterization.Results—Seven of the 10 patients recruited had their TIPS revised.Of these 7, the data from 2 were discarded because 1 had a deepshunt (14–15 cm due to ascites) and therefore insufficient signal power,while the other had a completely thrombosed shunt. Results from the remaining5 patients show prerevision flows of 500 to 1200 mL/min andpostrevision flows of 1300 to 2550 mL/min. A corresponding decrease inthe prerevision and postrevision portosystemic pressure gradient was observedin each case. An important result was observed for patient 9, whoseprerevision flow was 1910 mL/min, which suggests a revision may be unnecessary.Following shunt revision, the pressure gradient for patient 9was unchanged, and postrevision flow was 1938 mL/min, effectively unchangedcompared to prerevision flow.Conclusions—Results demonstrate that shunt volume flow hasa negative correlation with the prerevision and postrevision portosystemicpressure gradient, illustrating that volume flow may be an effective indicatorof shunt performance.1541365 Implementation of a Competency-Based Online Curriculumto Train Medical Students and Primary Care Residentsand Physicians in Point-of-Care UltrasoundNicholas Cohen, 1 * Justin Lappen, 1,2 Honor Wolfe, 1 KimberlyGecsi, 2 Ashish Bhimani 3 1 Family Medicine and CommunityHealth, 2 Obstetrics and Gynecology, 3 Cardiology, UniversityHospitals Case Medical Center, Cleveland, Ohio USAObjectives—The objective of our study was to design and integrateinto the medical school curriculum at Case Western Reserve UniversitySchool of Medicine and the family medicine residency curriculum atUniversity Hospitals Case Medical Center a competency-based online curriculumto train medical students and residents in point-of-care ultrasound.Methods—We assembled a multidisciplinary team of physiciansin obstetrics and gynecology, cardiology, and the Department of FamilyMedicine at our institution to design the curriculum. The modules consistof an introduction to ultrasound and modules focused on specific applicationof point-of-care ultrasound for obstetrics, cardiology, abdominal, vascular,and procedure guidance. Each module includes a didactic componentfeaturing a Web-delivered screen capture PowerPoint video by an expert inthe field, a demonstration of technique using a model and actual ultrasound,an online pretest and posttest to ensure competency, and a downloadablechecklist for a hands-on evaluation by a credentialed sonographer.