Official Proceedings - AIUM

American Institute of Ultrasound in Medicine Proceedings J Ultrasound Med 32(suppl):S1–S134, 2013serum screen, 46.2%; ultrasound anomaly, 28.6%; and/or family history,4.4%. Patients that chose dDNA were not billed up front, and no informationon their out-of-pocket costs was available. Patients that choseMPSS testing required some prepayment. Of the 53 patients with a knownup-front charge, it was $235 for 26 and $475 for 27 patients.Conclusions—The most common indication for cffDNA testingwas advanced maternal age. The testing was most commonly done inthe early second trimester, and it took an average of 10 days for results.There was a higher rate of test failure in the dDNA group (12%). The outof-pocketcost prior to testing may affect the patient’s desire for testing.1536107 Hospital-Wide Survey of Bacterial Contamination of Pointof-CareUltrasound ProbesMatthew Lawrence, 1 * James Blanks, 2 Ruben Ayala, 2 JoelSchofer, 1 Diana Macian, 1 Douglas Talk, 3 Jessie Glasser 41Emergency Department, Naval Medical Center Portsmouth,Chesapeake, Virginia USA; 2 Laboratory Services, MicrobiologyDivision, 3 Obstetrics and Gynecology, 4 Internal Medicine,Infectious Disease Division, Naval Medical Center Portsmouth,Portsmouth, Virginia USAObjectives—With the increasing use of point-of-care ultrasoundin many areas of medicine, there is a concern that ultrasound equipmentcan facilitate transmission of infection to patients, especially methicillinresistantStaphylococcus aureus (MRSA). The primary objective of thisstudy is to determine the prevalence of bacterial colonization on hospitalwidepoint-of-care ultrasound probes by performing cultures of the probes.Our hypothesis is that bacterial contamination is not a significant problem,and that our current ultrasound probe cleaning protocols are sufficientto protect patients against such nosocomial spread of infection.Methods—The study was conducted at a single military hospitalon 43 point-of-care ultrasound machines (87 probes) located within 9 departmentsover an 8-week period. Every probe was cultured 4 times duringthe study period, at 2-week intervals. Intracavitary probes were excludedfrom the study due to high-level disinfection protocols at our institution.Positive cultures underwent species identification in the microbiology lab.Results—At the time of this submission, the first half of datacollection was complete (2 culture sets performed on each machine, 2 culturesets remaining). Of the 174 probe cultures, 13 resulted in positivegrowth (7.5%). Three cultures (1.7%) identified Micrococcus species, and8 cultures (4.6%) identified coagulase-negative Staphylococcus, both ofwhich are common human skin flora. Three cultures (1.7%) identifiedBacillus species, not B anthracis or B cereus. Finally, 3 cultures (1.7%)identified Pseudomonas species, which was not P aeruginosa. No culturesidentified MRSA.Conclusions—As hypothesized, bacterial contamination ofpoint-of-care ultrasound probes is low and primarily involves organismscommon to normal skin flora and the environment. MRSA contaminationwas not identified at our institution. Antibacterial wipes after each useseem to prevent significant bacterial growth on ultrasound probe surfaces.(The views expressed in this article are those of the authors and do notnecessarily reflect the official policy or position of the Department of theNavy, Department of Defense, or the United States Government.)1536431 A Novel Approach to Visualizing the Vasculature Architectureof the Placenta Using 3-Dimensional Slicer Software:A Pilot StudyRie Oyama, 1 * Chizuko Isurugi, 1 Tomonobu Kanasugi, 1 AkihikoKikuchi, 1 Toru Sugiyama, 1 Sonia Pujol, 2 Ron Kikinis 21Obstetrics and Gynecology, Iwate Medical University,Morioka, Japan; 2 Radiology, Brigham and Women’s Hospital,Boston, Massachusetts USAObjectives—The aim of this pilot study presents a novel approachto visualize the vasculature architecture of the placenta usinggrayscale to acquire volume data of the villous tree from the 3D ultrasoundmachine, and then these data restructure the placental vasculatureusing 3D Slicer software, which is an open-source medical visualizationand analysis software package for medical image computing.Methods—We used a Voluson E6 (GE Healthcare) system witha RAB4-8-D/OB 3D/4D 8-MHz transabdominal wideband convex volumetransducer. The 3D volume image was adjusted to include the entireplacenta. The volume data set was stored in the DICOM format for restructuringon the 3D Slicer software. This study included 2 women withsingleton pregnancies seen at 16 and 20 weeks at Iwate Medical UniversityHospital. Informed consent was obtained from each patient. The InstitutionalReview Board approved this study. The raw volume data wereimported into the Slicer software, which was loaded to display on the 2Dviewer (axial, sagittal, and coronal), and then the 3D image was displayedon the 3D viewer. The 3D volume image restructured the placental vasculatureusing volume rendering, and the manual segmentation moduleand label statistical analysis were used. (1) Volume-rendering module: Wedetermined region of interest of the placenta. Parameter set: The presetchosen was CT-AAA, and the rendering used VTK CPU casting. (2) Manualsegmentation module: Threshold Paint was used to create a region ofinterest of the placenta and an umbilical cord image, which was based onthe grayscale volume of original raw data. (3) Label statistical analysis:This module counted the number of voxels, which was the 3D volumeimage of the placenta displayed using the manual segmentation.Results—This study showed the placental vasculature of theultrasound image using 2 module methods. The number of voxels (10 ×3) at 16 weeks was 60.519 and at 20 weeks was 193.934.Conclusions—The 3D Slicer visualized the vasculature architectureof the placenta, which came from raw ultrasound data. Also, it willbe able to impact the filed of obstetric ultrasound and elucidation of theplacenta.1536710 Efficacy of Ultrasound-Guided Tibial Nerve PerineuralInjections at the Posterior Tarsal TunnelOliver Joseph,* Oleg Uryasev, John McNamara, ApostolosDallas Virginia Tech Carilion School of Medicine, Roanoke,Virginia USAObjectives—Compression of the tibial nerve (TN) within thetarsal tunnel results in posterior tarsal tunnel syndrome. Like other nervecompression syndromes, corticosteroid injections are a potential therapeuticmodality. We hypothesize that one can effectively inject the TNperineural space immediately proximal to the tarsal tunnel.Methods—This research is a pilot study to investigate the efficacyof TN perineural injections bilaterally on 4 cadaveric models.A 10–5-MHz small linear array transducer was placed along the medialmalleolus and Achilles tendon to visualize the neurovascular bundle. TheTN appeared spindle shaped with alternating hypoechoic and hyperechoicbands superficial and anterior to the flexor hallucis longus tendon. Anteriorlong-axis injections of 0.35 mL of 0.5% methylene blue with subsequentanatomic dissection were confirmatory. Injections were designatedaccurate (nerve stained) and precise (no damage to adjacent anatomy).Results—Five of 8 (63%) injections were accurate and 6 of 8(75%) precise. Initial attempts were unsuccessful, while later injections wereaccurate and precise. The most apparent source of error was from 1 cadaver’spronounced musculoskeletal deformity, which precluded successful injectionsbilaterally. Of the 3 cadavers unaffected by musculoskeletal deformity,accuracy was 5 of 6 (83%), and precision was 6 of 6 (100%).Conclusions—While surgery is the definitive treatment for refractoryposterior tarsal tunnel syndrome, corticosteroid injections couldlikely provide symptomatic relief and postpone surgical intervention. Thisstudy suggests that ultrasound guidance can increase accuracy and precisionand is a potential adjunct to treatment. Future study will expand theinitial data set and allow for a consistent protocol, while later studies of patientoutcomes will demonstrate clinical relevance.S92