Official Proceedings - AIUM

American Institute of Ultrasound in Medicine Proceedings J Ultrasound Med 32(suppl):S1–S134, 2013healthy, based on microvessel morphologic differences. Thus, contrastenhancedacoustic angiography presents a means to detect the presenceof tumors based on observed microvascular abnormalities, without theneed to evaluate the tumor mass itself.Pediatric Hepatobiliary DisordersModerator: Rob Goodman, MDSonographic Differential Diagnoses in Pediatric Focal Liver LesionsRob Goodman Yale University, New Haven, ConnecticutUSASonographic analysis of the pediatric liver is often the first imagingused that detects a focal liver lesion. Assessment of the sonographicappearances of these lesions can sometimes be challenging if one is expectedto determine a likely cause. The spectrum of conditions that giverise to focal liver lesions in a child is broad, and many lesions have similarsonographic appearances. In this session, congenital, inflammatory,traumatic, neoplastic (benign and malignant), vascular, and metaboliccauses of focal liver lesions will be discussed, and specific clinico-sonographicfeatures used to distinguish between these will be emphasized.With the help of these features, the practicing pediatric sonographer willbe able to more accurately reach an appropriate diagnosis.The Spectrum of Ultrasound Findings in the Pediatric Biliary TreeValerie Ward Radiology, Boston Children’s Hospital, Boston,Massachusetts USA3-hour time window. Systemic tPA administration remains the fastest wayto initiate treatment for acute ischemic stroke. Since tPA works by inductionof partial recanalization of large thrombi, early augmentation of fibrinolysisto improve recanalization is desirable. This augmentation isfeasible and can be safely achieved at the bedside with transcranialDoppler (TCD), or sonothrombolysis. In the CLOTBUST trial, all patientsreceived systemic tPA as the standard of care, and 73% of patientsachieved any recanalization (46% complete, 27% partial) with tPA + TCDvs 50% (17% complete, 33% partial) with tPA alone within 2 hours oftreatment (P < .001). Sustained complete recanalization at 2 hours was38% vs 13%, respectively (P = .03). A recent meta-analysis of 6 randomizedand 3 nonrandomized clinical studies of sonothrombolysis showedthat any diagnostic ultrasound monitoring can at least double the chanceof early complete arterial recanalization at no increase in the risk of symptomaticintracerebral hemorrhage. Transcranial ultrasound delivery in anoperator-independent and dose-controlled manner was successfully testedin phase I and II clinical studies in stroke-free volunteers and stroke patientstreated with systemic tPA. A novel operator-independent device forsonolysis (Cerevast Therapeutics, Inc) is now being tested in a pivotalphase III clinical trial (CLOTBUSTER, NCT01098981).Animal Models of Sonothrombolysis and Drug DeliveryChristy Holland, 1 * Jonathan Sutton, 1 Nikolas Ivancevich, 2Stephen Perrin, 1 Deborah Vela 3 1 Internal Medicine, Divisionof Cardiovascular Diseases and Biomedical EngineeringProgram, University of Cincinnati, Cincinnati, Ohio USA;2Siemens Medical Solutions, Issaquah, Washington USA; 3 CardiovascularPathology, Texas Heart Institute, Houston, TexasUSAUltrasound is the imaging modality of choice for the initial andnoninvasive evaluation of biliary diseases in newborns, infants, youngchildren, and adolescents. Initially in this presentation, patient preparation,sonographic technique, and common clinical indications for sonographyof the biliary tract will be reviewed. Then both the common andinfrequent etiologies for biliary disease in children, including cholestasis,cholelithiasis, choledochalithiasis, cholecystitis, cholangitis, choledochalcysts, and biliary atresia, will be discussed. Also, the correlation of prenataland postnatal sonography will be presented for specific biliary tract diagnosesthat can be diagnosed in the fetal period. Where applicable, the benefitsof combining sonography with other biliary tract imaging modalities(such as hepatobiliary scintigraphy, cholangiography, and magnetic resonancecholangiopancreatography) will be also discussed as adjuncts in theevaluation of pediatric biliary tract abnormalities.Taboos and Opportunities in Sonothrombolysis forStroke: From Sonothrombolysis in Animals to StrokeTreatment in PatientsModerators: Tatjana Rundek, MD, PhD,Paul Sierzenski, MD, RDMSUps and Downs in Clinical Trials of SonothrombolysisAndrei Alexandrov Comprehensive Stroke Center, Universityof Alabama, Birmingham, Alabama USAIntravenous tissue-type plasminogen activator (tPA) remainsthe only effective reperfusion therapy to reverse ischemic stroke. Its timelydelivery to all eligible patients should be a priority in development ofstroke treatment centers and ambulance delivery systems. Its augmentationwith ultrasound will be discussed. Despite lower revascularizationrates with respect to endovascular thrombectomy, patients treated withsystemic thrombolysis achieve good functional outcomes likely due toearlier treatment initiation. Currently, no evidence exists that primary intraarterialrevascularization could be any better than systemic tPA within theS7Ultrasound-mediated thrombolysis, or sonothrombolysis, is anattractive adjuvant to conventional recombinant tissue-type plasminogenactivator (rt-PA) therapy for acute ischemic stroke and other thromboocclusivediseases. Numerous in vitro and ex vivo porcine studies havedemonstrated ultrasound-enhanced clot lysis, yet recent clinical trials haveproduced mixed results. Stable cavitation nucleated by an ultrasound contrastagent enhances the penetration of both rt-PA and plasminogen intoclots. This enzymatic fibrinolysis is likely hastened due to an increasedavailability of plasminogen binding sites for rt-PA. However, the degreeof clot retraction strongly affects the extent of thrombolytic efficacy. Thelack of dense fibrin matrix formation throughout unretracted clots promotessusceptibility to ultrasound-enhanced thrombolysis. In contrast, thepaucity of plasminogen present within retracted clots prevents ultrasoundacceleration of lysis. Thus, the thrombus etiology and vascular origin maypredispose the degree of sonothrombolytic susceptibility. Recent clinical,in vitro, and ex vivo data from a variety of clot models will be discussed.Neurovascular Ultrasound in Stroke: What Sonographers Can Do NowTatjana Rundek Neurology, University of Miami MillerSchool of Medicine, Miami, Florida USANeurovascular examination is widely used for assessment ofpatients in the acute, subacute, or chronic phases of cerebral ischemia. Theavailability of aggressive and effective treatments, which can be potentiallyharmful for acute ischemic stroke patients, requires fast and noninvasiveexamination of the intracranial and extracranial vasculature.Effective stroke therapy can be improved through real-time ultrasoundmonitoring of the neurologic and cardiovascular responses to treatments.This requires crucial knowledge on behalf of both the sonographer andstroke physician to make the best decisions for the patient, which wouldminimize the ischemic damage caused by stroke and reduce the risk ofsubsequent stroke. Current ultrasound techniques, transcranial Dopplerand extracranial duplex or color Doppler, have the potential to providecrucial and reliable information about the status of the intracranial and extracranialarteries in a real time. Application of echo-enhancing agentspromises to effectively extend current diagnostic techniques. Application