RESULTS: Primary Symptom:Bleeding - 60% (n=2l)Pain - 26% (9)Other - 14% (5)Clinicaloutcomes:Complete resoJution: 40% (14)Significantimprovement: 42.9% (15)Unchanged: 14.3% (5)Worsened: 2.9% (l)Menstrual Status:regular menses: 51.4% (18)irregular menses: 22.9% (8)no periods: 25.7%(9)Average age- 48.1, range- 44-55 years old.Current Medications:82.9% (29)none8.6% (3) pain medication8.6% (3) ho'rmonal therapy.Adjuvant Therapy:94.3% (33) no further treatment.2.9%(I)D&C2.9% (1) myomectomy.

CONCLUSION: UAE long term outcome results show 83%of patients had resolution or significant improvement insymptoms with 94.3% of patients requiring no further medicaltreatment. Our study confirms that the early benefits ofUAEare still present on long term followup. NB - Data for theremining 114 patients is still being collected at the time of thisabstract submission.

Poster No. 288

Pregnancy FoIlowing UAE (Uterine Artery Embolization)with PVA (Polyvinyl Alcohol) Particles.M.D. Kim, Bundang CHA General Hospital,Pochon CHAUniversity, Sungnam, Kyonggi-do, Republic ojKorea • E.H.Lee • J.H. Won. D. Y. Lee

PURPOSE: The effects of UAE with PVA particles on theferti li ty are still uncertain. Therefore, the purpose of thisstudy is to assess the pregnancy rate following the UAE withPVA.

MATERlALS AND METHODS: Among the patients receivingUAE with PVA particles due to uterine myoma oradenomyosis between 1998 to 2001, there were 94 patientsof childbearing age (20-40 years old). The data were collectedby reviewing the rnedical records and telephone interviews.Patients using contraceptions and unmarried women wereexcluded. The possibility of infertility caused by the spousewas ignored. The clinical response of irnpregnated womenand the size of PVA particles used were analyzed.

RESULTS: Among 94 patients who received UAE with PVA,there were 74 cases of wornen on contraceptives, 6 cases ofunrnarried women, and 9 patients were lost during the followup. Thus only five patients remained who desired futurepregnancy. Follow up periods were between 22 to 47 months.Among the five pregnancies, four cases (80%) were wantedpregnancies; one case was pregnancy due to failedcontraception. Four patients had normaI delivery withoutevidence of intrauterine growth retardation or premature baby.One case offailed contraception underwent artificial abortion.Irnproved symptoms of dysmenorrhea or menorrhagia werealso demonstrated on short term and midterm follow up in aUimpregnated women. The size of PVA particles used was asfoIlows: 255-3551lm (n=2), 355-S001lrn (n=l), 500-7001lrn(n=2).

CONCLUSION: Even though the absolute number of case issmali, UAE with PVA particles did not affect the fertility.

Poster No. 289

Technical Success, Peri-Interventional Complicationsand Radiation Exposure.T.J. Kroencke, Department ojRadiology, Charite, Berlin,Germany • J. Kettenbach • A. Gauruder-Burmester • M.Taupitz • C. Scheurig • R. Puls. J. Neymeyer • B. Hamm

PURPOSE: Toevaluate procedural success, peri-interventionalmorbidity and radiation exposure of patients undergoing UFE.

MATERIALS AND METHODS: Bilaterai UFE was perfonnedin 75 consecutive pts with syrnptomatic uterine fibroidsbetween October 2000 and August 2002. An analysis withrespect to technical success, use of different catheters andembolization material, peri-interventional complications (~72

hours), procedure time and radiation exposure was performed.

RESULTS: BilateraI UFE was successful in 73175 pts (97.3%).In 2 pts (2.6%) unilateral embolization was performed becauseof absence ofthe uterine artery (UA) or inability to catheterizethe UA. In 12175 pts (16%) a 3F Microcatheter had to beused in addition to a standard diagnostic catheter due to smalicaliber, spasm, acute-angJed origin of UA or prominent cervico­vaginal branches. Trisacryl-gelatine coated microspheres wereused in 60 pts while a cornbination of microspheres and gelfoamwas used in 14 and PVA particles were used in one patient forembolization. Peri-interventional complications occurred in 2pts (2.6%); perforation of extemal iliac artery, perforation ofuterine artery. Median procedure time was 108 min (76-25),median f1uoroscopy time 13.2 min (5-52), median dose areaproduct 8737,4 cGy*cm2 (3324,00-38117,00).

CONCLUSION: Bilaterai UFE proved to be a safe procedurewith negligible peri-procedural compJications that can beperformed with a standard diagnostic catheter in most cases.Radiation exposure of the patient can be kept at a moderatelevel with a standardized approach.

Vascular ImagingPoster No. 290

The Relationship between Inferior Mesenteric ArteryFlow and Aneurysmal Sac Shrinkage after Stent­Grafting for AAA.S. Sakaguchi, Nara Medical University, Kashihara, Nara,Japan • K. Kichikawa • W Higashiura • T Hirai • H.Ohishi • H. Uchida

PURPOSE: To deterrnine the association of inferior mesentericartery (IMA) f10w change with the aneurysmai sac diameterafter stent-grafting (SG) for abdominal aortic aneurysm (AAA)during the first week.

MATERIALS AND METHODS: On postoperative day (POD)l and POD 7, color Doppler and contrast-enhanced ultrasoundexaminations were perforrned in 26 patients (25 men and 1woman, mean age: 75.7, range: 55-86 years) with patent IMAfrom AAA preoperatively lO examine the blood f10w ofIMAs.Patients were categorized into 3 types: type-A (no type-2endoleak frorn IMA on PODl and POD7), type-B (type-2endoleak from IMA on PODl and no endoleak on POD7),type-C (type-2 endoleak from IMA on PODl and POD7) todetermine the correlations between IMA blood f10w changeand the shrinkage of AAA within 6 months after SG atcontrast-enhanced CT.

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RESULTS: In 15 of 26 patients, proximal IMA blood flowswere not deteeted and distal IMA bIood flows supplied fromanastomotie vessels were seen by eolor Doppler and eontrast­enhaneed ultrasound on POD I. In the other 11 patients, baekflow endoleaks from IMA were deteeted on POD 1, and 4 of11 endoleaks disappeared spontaneously and the rest 7endoleaks remained on POD 7. Twenty-six patients weredivided into 3 types: type-A (n=15), type-B (n=4), type-C(n=7). The differenees in aneurysmai sae diameter between lweek and 6 months after SGing ranged from 1 to 14 mm(mean 5.9) in type-A, Oto 9 mm (mean 3.3) in type-B, -1 to5 mm (mean 1.0) in type-c. Statistieal differenees betweentype-A and type-C (P=O.OlO) were eonfirmed by Student t­test. P-value between type-A and type-B, type-B and type­C were 0.28, 0.26 respeetively.

CONCLUSION: This study suggests that eolor Dopplerultrasound examination of the IMA blood flow ehange is usefulfor predietion of aneurysmaI sae shrinkage after SGing forAAA.

Poster No. 291

Time Resolved Magnetic Resonance Angiograpby as aNon·lnvasive Method To Classify Endoleaks: InitialResults.R.A. Lookstein, Mount Sinai Medical Center, New York, Nr,USA. J. Goldman • L. Pukin • K.S. Chae • M.L. Marin

PURPOSE: To report initial results with the use of timeresolved magnetie resonanee angiography (TR-MRA) toclassifyendoleaks.

MATERIALS AND METHODS: Between July and September2002, five patients, four male and one female, (ages 70-82,mean 77) who had undergone endovaseular repair of an aortieaneurysm with the Talent endovaseular stent graf!, underwentTR-MRA and high resolution MRA to elassify previouslydoeumented endoleaks. Four patients had abdominal bifureateddeviees and one patient had a thoraeie deviee. TR-MRA hadaequisition times ranging from 0.6 see to 4sec per frarne. Severaldozen frarnes were aequired to obtain a eine angiogram overthe stent graft. High resolution MRA had multipleaequisitions with times belween 18 and 24 seeonds peraequisition. Arterial, venous, and delayed phase images wereoblained.

RESULTS: High resolution MRA identified an endoleak in allfive patients. TR-MRA was able to loealize the endoleak inall five eases. The thoraeie endoleak was classified as a distaltype Ileak. Of the four abdominal deviees, two were classifiedas type 1, (one proximal and one distal) and two were classifiedas type 2. Of the type 2 leaks, TR-MRA identified the inferiormesenterie artery as the feeding vessel in one ease and identifiedan iliolumbar artery as the feeding vessel in the seeond ease.TR-MRA was able to demonstrate the direetion of flow inthe endoleak eavity in four of the five eases.

CONCLUSION: TR-MRA is an effeetive non-invasivemethod to distinguish between type I and type 2 endoleaks.

Poster No. 292

Paget-Schroetter Syndrome: Comparison of GadoliniumEnhanced MR to Conventional Venography.p. V. Kavanagh, Wake Forest University School ojMedicine,Winston-Salem,.NC, USA. S.E. Kaminisky • S.P. Loehr

PURPOSE: To eompare the diagnostie aeeuraey ofMRI witheonventional venography (CV) in patients with suspeetedaxillo-subclavian venous thrombosis (AS-DVT). Whenthrombosis was identified, anatomie risk faetors were sought.

MATERIALS AND METHODS: 20 patients presenting withunilateral upper extremity swelling were evaluated with MRIand Cv. Patients with indwelling eatheters were exeluded.MRl initially used a eardiae gated double inversion recoverysequenee in the axial and sagittal planes. Direet MRvenography was then empłoyed using dilute gadolinium (lOee in 250 ee normal saline), injected at 2 ee/seeond via a veinon the radial aspeet of the wrist on the affeeted side. A 3D­TOF-SPGR sequenee was used. This was repeated with thepatient performing the ABER maneuver. Conventionalvenography was performed with digital subtraetionangiography (1 frame/seeond) using 60 to 100 ee ofnonionieeontrast medium (350mg/ml). The exarnination was earriedout with the arm supinated and repeated during the ABERmaneuver. Rib and muscle abnolmalities were sought.

RESULTS: 11120 (55%) had AS-DVT. Both MR and CVwere 100% sensitive in the deteetion ofthe venous thrombosis.The diagnosis eould be made with equal eonfidenee usingeither teehnique. Charaeterization of anatomie risk faetorswas superior with MRI. 6/11 positive eases had an anatomiepredisposing faetor identified by MRI, whereas eonventionalvenography identified an anatomie risk faetor in 3/11. Pinehingof the vein between adjaeent osseous slruetures was the mosteommon anatomie predisposing faetof. Where thrombosis wasidentified by eatheter venography, patients underwentthrombolysis during the same proeedure.

CONCLUSION: MRI provides oplional depietion ofintravaseular and extravaseular anatomy in patients with axillo­subclavian venous thrombosis. Au underlying anatomie riskfactor can be identified in a higher proportion of cases withMRl eompared with eatheter venography. Many such patientsrequire surgieal eorreetion of this predisposing anatomie riskfaetor in addition to endovaseular thrombolysis. Patientswithout anatomie risk faetors ean be defmitively treated withlranseatheter thrombolysis eommeneed at the same time astheir diagnostie venography.

Poster No. 293

Correlation between Infrarenal IVC Shape andMorpholgy Via Intravascular Ultrasound during FiIterPlacement.J.R. Perno, Thomas Jefferson University, Philadelphia, PA,USA. K.L. Sullivan • J. Bonn. G.A. Gardiner. D.J.Eschelman • c.F. Gonsalves

PURPOSE: Infrarenal IVC (HVC) filter plaeement is anaeeepted means of prevenling pulmonary embolism.Intravaseular ultrasound (IVUS) had been studied in theplaeement of IVC filters. The suprarenal IVC has been wellstudied transeutaneously. However, alterations in IIVC shapewith phases of respiration and pressure have not been wellevaluated. A better underslanding of the latter changes mayimprove fil ter deployment, i.e., less fil ter tilting and legasymmetry, leading to improved thrombus-trapping effieieney.

MATERIALS AND METHODS: This prospective IRB­approved study of 30 patients undergoing Greenfield HVCfil ter pJacement has enrolled 7 subjects. During phases ofrespiration (quiet breathing, maximai inspiration/expirationand Valsalva) pressure measurements via an intracaval catheterand short and long axis dimensions of the rrvc with IVUS areobtained at the planned site of filter placement. Followingfilter deployment IVUS and radiography is performed toevaluate leg placement and caval morphology.

RESULTS: Compared to quiet respiration, there was anincrease in the average HVC pressure of 1.7, 2, 19.2 mrnHgduring maximał inspiration, expiration and Valsalva,respectively.

Fiłter łeg asymmetry will be evaluated with IVUS andcorrelated with HVC morphology.

Mean Caval MeasurmentsQuiet Quiel Maxium Maxium Maxiumrespiration respir- Inspir- Inspir- Expir-LA alian SA alian LA alian SA alion LA

Mean 23.63 11.76 23.9 15.84 23.64Standard 1.49 3.34 3.54 3.6 1.89devlationall measurements in mm, LA=long axis, SA=short axis

MaxiumExpir­atlon13.894.14

Valsalva Vals-LA alvaSA SA21.29 13.693.37 4.49

CONCLUSION: Semiautomated quantitative renal arterystenosis analysis using the Medis QVA ostial segment analysisprogram in patients undergoing gadolinium renal arteryangiograms may be a useful method for measuring renal arterystenosis for clinical triais evaluating percutaneous translurninalrenal angioplasty and stent therapy.

Poster No. 295

CT Angiography vs. MR Angiography: ComparativeAnalysis or Imaging Characteristics or Vascular StentsIn Vitro.M. Honda, Showa University Fujigaoka Hospital,Yokohama, Kanagawa Pref, lapan • M. Obuch i • H.Sugimoto • K Kuroki • K Takizawa • Y. Nakajima

PURPOSE: To describe imaging characteristics of vascularstents using CT angiography (CTA) and MR angiography(MRA) in vitro, and to deterrnine which technique is moresuitable to observe stent appearance and delineation of thelumen.

CONCLUSION: Smali changes in HVC pressure can causemarked alterations in morphology. Maximum inspiration andValsalva produced a more nearly circular HVC than quietrespiration or maximum expiration. Filter deployment in amore nearly circular HVC could potentially result in moresymmetric leg placement, which will be evaluated as morepatients are recruited.

Poster No. 294

Comparison orManuałand Semiautomated QuantitativeRenal Artery Stenosis Analysis.D.J. Spinosa, University ofVirginia, Charlottesville, VA,USA • G.D. Hartwell • E. Bissonette • l.F Angle • KD.Hagspiel • D.A. Leung

PURPOSE: To compare the results from semiautomatedquantitative vascular analysis techniques for measuring thedegree of renal artery stenosis (RAS) with manualmeasurements from gadolinium digital renal angiograms.Quantitative vesssel analysis (QVA) software is commonlyused to measure the degree of stenosis pre and postendovascular treatment in clinical triais. The abiłity to measureRAS on gadolinium angiograms using this technique couldresult in allowing patients to receive gadołinium contrast agentsas part of clinical triaIs to evaluate treatment of RAS in patientswith rena! insufficiency.

MATERIALS AND METHODS: Fifteen gadolinium digitalrenal angiograms were selected that demonstrated at least oneopacified main renal artery for which a team of fiveinterventional radiologists agreed on the degree of diameterstenosis within ± 5% using manuał measurement with handheld calipers. The degree of stenosis for these 15 renał

angiograms was compared to measurements detennined usingthe quantitative vascular analysis (QVA) osteal segmentanalysis stenosis package from Medical Imaging Systems(Medis) using a semiautomated technique which allowed formanuał adjustrnent of the contrast filled vessel border prior tocalculating the degree of stenosis.

RESULTS: Comparison of serniautomated measurements ofthe degree of renal artery stenosis with manual measurementsusing hand held calipers demonstrated no significant differencein the measured degree of stenosis (p=0.39). The meanageement was -3.89% (Standard Deviation = 17.09%, 25thpercentile = -13.08% and 75% percentile = +8.58%)

MATERIALS AND METHODS: Three types of Palmaz stent(long-medium,large, medium), Passager stent-graft, Wallstent,and SMART stent were inserted into acrylic tubes (lO mm indiameter, 20 cm in length). Each tube was filled with dilutedIoparnidol (300 mgUml) at a concentration of 1/25 for CTA,and Gd-DTPA at a concentration of 11500 for MRA. Thesetubes were emerged into a container filled with water. CTAwas performed by an Asterion Multi CT (Toshiba). Thescanning parameters were 3-mm norninal section thickness, apitch 00.0, and a 0.75-second gantry rotation period. Sourceirnages of CTA were processed into vo)ume rendering (VR),maximum intensity projections (MIP), and multi planarreformations (MPR) images with a workstation (ToshibaAlatoview). MRA was performed by aSigna Horizon 1.0 TMR scanner (GE). Fast SPGR images were obtained withfollowing parameters: a repetition time of 6.2 ms, an echotime of lA ms, a f1ip angle of20 degrees, and an inversion timeof 31 ms. Source images in MRA and VR, MIP and MPRimages in CTA were evaluated regarding artifact size, visibilityof the stent configuration and lumen.

RESULTS: In CTA, all stents produced no apparent artifacts.While the detailed configuration of Passager and SMARTstents were observed on MIP and VR, the mesh of Palmazand Wallstent were not depicted. AlI stents showed noprominent reduction of inner lumen on MPR images. In MRA,large Palmaz stent produced a growing artifacts size beyondits signal void. Long-medium and medium Palmaz stentsproduced rim-like artifacts. Passager, Wal1stent, and SMARTstent produced a slight artifact on their edges. The intraluminalsignals were hard to observe in Palmaz stents. Passager,Wallstent, and SMART stent showed a slight reduction ofinner lumen.

CONCLUSION: CTA consistently depicted the stentanatomy regardless of their structure and we conduded thatCTA was more suitabłe to depict stent appearance and innerlumen than MRA.

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Poster No. 296

CT and MR Imaging or Nitinol Stent with TantalumMarkers.G. Soulez, CHUM- Notre Dame, Dept. ojRadiology,Montreal, QC, Canada • L. Letourneau • G. Beaudoin • N.Boussion • v.L. Oliva • G. Cloutier

PURPOSE: To evaluate imaging characteristics of a nitinolstent with dis tal tantalum markers (Luminex Stent) withcomputed tomography (CT) scan and magnetic resonance(MR) imaging.

MATERlALSANDMETHODS: A vascularphantom was builtto simulate in-stent restenosis. The in-stent restenosis modelwas imaged with CT scan with different orientations to the z­axis and with MRI in different positions relative to both BOand the readout gradient. Stenosis measurements obtainedwith CT scan and MRI were compared to conventionalangiography. In-stent signal intensity obtained with differentflip angles was assessed for the Luminex stent and comparedto two other nitinol self-expandable stents.

RESULTS: Stent lumen could not be analyzed with CT scanwhen the phantom was perpendicular to the z-axis because ofstreak-like artifacts induced by tantalum markers. Theseartifacts were more limited when the phantom was in theparanel and oblique orientations relative to the table axis ifcoronal and sagittal multiplanar reconstructions wereperformed. With MR, metallic artifacts were mostly relatedto the stent orientation with BO, whereas orientation of thereadout gradient had little influence. Tantalum markers inducedslightly larger artifacts than the free ends of the nitinolMemotherrn-FLEXX stent, but this was not a lirnitation foranalyzing the in-stent lumen. Higher flip angles did notimprove the signal intensity inside the stents that were tested.The mean error for stenosis measurements varied between ­0.2% to + 6.1 % for CT acquisitions in parallei and obliquepositions and 3.6 % to 9.3% for the various MR acquisitions.

CONCLUSlON: Streak-like artifacts induced by the tantalummarkers hampered CTscan imaging of the Luminex stent.Therefore, MR angiography is better suited for follow upevaluation of this stent.

Poster No. 297

Flow Changes by Transonics Ultrasound in ThrombosedHemodialysis Grafts: Preliminary Results.J.L. Friese, Mayo Clinie Roehester, Roehester, MN, USA •S. Misra • J. Net. H. Bjamason • E. Sahater • A. Stanson,et al.

PURPOSE: KDOQI guidelines recommend the use oftransonics ultrasound for screening hemodialysis grafts toprevent thromboses. Since January 2000, all hemodialysispatients have been screened with quarterly transonicevaluations. The purpose of this retrospective review was toevaluate the flow changes after a successful percutaneousthrombectomy of a thrombosed polytetrafluoroethylene graft.

MATERJALS AND METHODS: A review of all Mayo ClinicRochester hemodialysis patients who had fistulogram withpercutaneous thrombectomy and post transonics ultrasoundevaluation from January 2000 to June 2002 was performed.Fourteen patients had 23 percutaneous thrombectomyprocedures performed. Ali charts and fistulograms werereviewed.

RESULTS: There were 7 failures. The remaining 16 successfulprocedures had flow by transonic ultrasound measuring 1024± 420 mL/rnin.In 14 ofthese 16 procedures, this was the firstthrombosis. In this subgroup, there were 4 failures. In thesuccessful procedures, flows measured 1027 ± 505 mL/min.Ali procedures were performed using mechanicalthrombectomy devices or balloon extraction method.

CONCLUSION: A successful percutaneous thrombectomyhas high flows by transonic ultrasound. Future work willconcentrate on the relationship between the flow rate and thepatency of the procedure.

Poster No. 298

Transonic Ultrasound Flow Changes in HemodialysisGrarts Treated Percutaneously: Preliminary Results.J.L. Friese, Mayo Clinie Roehester, Roehester, MN, USA •S. Misra • J. Net • H. Bjamason • E. Stanson • C.M.Johnson, et al.

PURPOSE: KDOQI guidelines recommend the use oftransonics ultrasound for screening hemodialysis grafts. SinceJanuary 2000, all hemodialysis patients have been screenedwith quarterly transonic ultrasounds, and when indicated,they are referred for angiographic evaluation. The purpose ofthis study is to deterrnine if there are differences in flowchanges before and after a percutaneous intervention perforrnedon patients with polytetrafluoroethylene (PTFE) grafts versusarteriovenous fistulas (AVFs).

MATERIALS AND METHODS: A retrospective review of allMayo Clinic Rochester hemodialysis patients who hadfistulogram with pre and post transonics ultrasound evaluationfrom January 2000 to June 2002 was performed. Thirty sixfistulograms for both synthetic grafts and AVFs wereperforrned and comprise this interim analysis. Ali charts andfistulograms were reviewed.

RESULTS: Most procedures were angioplasty. For allprocedures on PTFE grafts, pre intervention flow rates were692 ± 377 and post-intervention flow rates were 965 ± 409mL/min. For aU procedures on AVFs, pre-intervention flowrates were 566 ± 291 and post-intervention flow rate was 915± 547 mLlmin. Flow changes were stratified for both groupsbased on location of the stenosis (see table).

CONCLUSlON: In PTFE grafts, intrgraft stenoses had themaxi mai flow increase after angioplasty folIowed by venousanastomosis, and finally a subclavian vein stenosis. Similarly,for AVFs, arteriaI to venous anstomosis had the maximai flowincrease folIowed by the cephalic outflow vein stenosis.

Flow changes in PTFE and AVF gralts after AngioplastyLocahon or Stenosis Pre Flow (mUmin) Post Flow (mUmin)PTFE Subclavian Vein Stenosis 765 +/. 233 873 +/- 231PTFEVenousanaslomosis 612+1-156 881 +/-560PTFE Intragraft stenosls 537 +/-285 986 +/- 251AVFs cephalic stenosis 457 +/- 169 860 +/. 625AVFs anaslom09is 490 +/- 208 1006 +/- 159

Poster No. 299

Transjugular Intrahepatic Portosystemic Shunt andPortal Vein Flow Measurements Using aThermodilutional Catheter.M. Itkin, Hospital oj University ojPennsylvania,Philadelphia, PA, USA. T. WI. Clark • JA Solomon • S. WStavropoulos • M.C. Soulen. S.O. Trerotola, et al.

PURPOSE: TIPS is an established technique for treating thecomplications of end stage liver disease. Little is knownabout blood flow rates in the portal vein or the TIPS itself. A

device recently introduced for measurement of hemodialysisA-V access flow during angioplasty potentially allows directmeasurement of flows in TIPS. While the original devicemeasures antegrade flow (catheter introduced with thedirection of flow in the vessel) a modified version of thedevice has been developed to study flow in TIPS, which isretrograde to direction of catheter introduction.

MATERIALS AND METHODS: Ali patients referred toInterventional Radiology for TIPS creation or revisionprocedures were included. Flow was measured at the end ofthe procedure first in the portal vein and then in the TIPSchanne!. Each measurement was repeated three times.Oemographic and laboratory data were collected.Measurements were made with a 6 F retrograde flow cathetersystem (Angioflow, Transonic, Ithaca NY).

RESULTS: Ten patients (mean age 55) were included in thestudy. Six of them underwent TIPS revision and four TIPScreation. The design of the catheter required at least 4 cmlength of the TIPS channe! to accurately estimate flow; onepatient with a 2 cm long shunt was excluded. Mean flow(± SD) in the main portal vein was 1177 (± 457) mI/min andin the TIPS 1769 (± 681) mI/min (p<O.OOI).]n all cases theflow in the main portal vein was lower than in the TIPSchanne!. The only patient that has TIPS flow less than 1000mi/min developed TIPS occlusion in one week. Two patientswere lost for follow up and the remaining patients have stillpatent TIPS (average 108 days follow up).

CONCLUSION: These preliminary data show that at thecompletion of a TIPS procedure flow in the shunt isconsistently higher than in the main portal vein. This may beexplained by reversal offlow in the right and left portal veins.Further studies are ongoing in our institution to determine ifflow can be used to predict post-procedure complicationssuch as encephalopathy and hepatic insufficiency.

Poster No. 300

Transeatheter Arterial Embolization for Patients withBlunt Liver Injury: Comparison of CT Images andAngiography.M. Takeyoshi, St. Mary Hospital Department ojRadiology,Kurume, Fukuoka, Japan • K. Kimura • H. Nishihara

PURPOSE: To clarify the efficacy and pitfalls ofTranscatheterArterial Embolization (TAE) for patients with blunt liverinjury.

MATERIALS AND METHODS: Between April1997 and luly2001, 20 blunt hepatic trauma patients were brought to ouremergency department. They consisted of 12 males(age 4-70years, mean 30 years) and 8 females(age 6-64 years, mean 35years). In all cases, contrast-enhanced CT was performedimmediatefy and severe liver injury was diagnosed. CT scanseverity was scored based on Mirvis' classification for blunthepatic trauma. Ali patients underwent hepatic angiographyafter CT exarnination and if findings such as active bleeding,pseudoaneurysm and/or arterio-portal shunt were confirmed,TAE was performed.

RESULTS: The severity on CT was classified as grade 3 in 9patients and grade 4 in 11. Extravasation was found in 1grade3 patient and 4 grade4 patients on CT, whereassubsequent hepatic angiography showed extravasation in agrade3 patient who had no extravasation on CT and in 2additional grade4 patients. Pseudoaneurysm and/or arterio­portal shunt were conflI111ed in 5 grade3 patients and 7 grade4patients. TAE was performed with gelform and/or microcoils

via subsegmental hepatic artery. Overall, 15 patients weretreated by TAE, and the shock index was significantly reducedafter TAE. During the follow-up perjod, infectious bilomadeveloped in 5 grade4 patients following TAE and the drainagetube had to be replaced to control the infection. Three of these5 patients had shown extravasation on either CT, hepaticangiography ar both. Five patients (4 grade3 and one grade4)were treated conservatively without TAE. Ali ofthe 20 patientssurvived, with a follow-up of 0.5-12 months(mean 3.7months).

CONCLUSION: TAE is an effective alternative to surgeryeven for patients with high-grade liver injury. After TAE,infectious biloma may develop, especially in high-grade liverinjury. The CT severity grade seemed to be useful forpredicting the clinical course of blunt liver injury.

Poster No. 301

Diminished Flow on Hepatic Angiography of LiverTransplant Recipients: A Predictor of Hepatic ArteryThrombosis.WE.A. Saad, University ojRochester Medical Center;Rochester; NY, USA. DL Waldman • D.E. Lee • L.G.Sahler. N.C. Patel. A. Bozorgzadeh, et al.

PURPOSE: To determine the etiology and outcome ofhepaticallografts that exibit sonographic and angiographic diminishedhepatic arterial flow.

MATERIALS AND METHODS: A retrospective chart reviewof liver transplant recipients from 01/1991 to 01/2002 (11years) diagnosed both sonographically and angiographicallyto have diminished hepatic artery flow.

RESULTS: Six patients were confirmed angiographically (aftersuspicious U/S evaluation) to have diminished hepatic arteryflow. Ali six were diagnosed wi thin 17 days of their transplant(mean of 5 days). Ali six had associated technical / surgicalfactors such as recent surgical revision of hepatic arteryanastomosis (1/6) or associated hepatic artery anomalies onangiographic evaluation (5/6) such as hepatic artery kinksand/or stenoses. Three of the six developed elements ofrejection. One allograft was surgically revised immediatelyafter angiography with good long term outcome (more than 2years follow-up). The remaining five (5/6) that were folIowedwithout surgical revision subsequently thrombosed at days:8,18,66,180 and 280 from the date of their initial angiogram.

CONCLUSION: Subjective slow hepatic artery flow byangiography is a predictor of eventual hepatic arterythrombosis and ultimately allograft failure. The proximity ofthe phenomenon (mean of 5 days) to the date oftransplantation and its high association with other hepaticartery angiographic abnormalities places surgical / technicalfactars as a more likely cause than graft rejection. Immediatesurgical revisions may help to decrease allograft loss. Aprospective study with both sonographic and angiographiccriteńa for diminished hepatic artery flow may be helpful inearly detection of preocclusive hepatic artery states.

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Poster No. 302

MR-Guided Catheter Tracking and MRA Using IR­TrueFISP: Optimal Contrast Agent Concentration in aStatic Phantom.B.E. Schirf, Northwestern University, Chicago, IL, USA.J.D. Green • S.M. Shea • J.e. Carr • D. Li • R.A. Omary,etal.

PURPOSE: Inversion recovery true fas t imaging with steady­state precession (IR-TrueFISP) is anovel interventionalmagnetic resonance (MR) sequence that may be used for bothcatheter tracking and MR-Angiography. The optimalconcentration ofdilute gadolinium (Gd) to maxirnize the signal­to-noise-ratio (SNR) using IR-TrueFISP is not known. Usinga static phantom, we aimed to measure the optimal Gdconcentration for catheter tracking and MRA with IR­TrueFlSP across a range of inversion times and inversionpulse f1ip angles.

MATERlALS AND METHODS: Using a 1.5T Siemens Sonatascanner, a static phantom of centrifuge tubes with Gdconcentrations from 0% (saline) to 10% in one percentincrements, was imaged using both IR-TrueFISP cathetertraeking and MRA sequences. The inversion time (TI) wasvaried from 40 to 60ms (IOms inerements) aeross a range ofinversion pulse flip angles from 120 to ISO degrees (20 degreeinerements) with twelve signal measurements per Gdeoneentration. The signal inside eaeh tube and the signal in airwere used to ealculate the SNR for eaeh Gd eonee~tration.

The resulting 132 SNR data points from eaeh sequeneeunderwent an analysis of varianee (ANOVA) and Tukeyeomparison test to determine statistieal signifieanee amongstthe Gd eoneentrations with Alpha set equal to 0.05.

RESULTS: Peak SNR values were obtained with a Gdeoneentration of 3% that was statistieally signifieant using(he MRA sequenee (p<O.OOl). Optimal values for IR­TrueFISP eatheter traeking were obtained with Gdeoneentrations of 3% and 4%. There was no statistieallysignificant differenee in SNR between the 3% and 4% Gdeoneentrations in the eatheter traeking group.

CONCLUSION: Based on these results in a static phantom,the optimal Gd eoneentration for interventional proceduresusing an IR-TrueFISP sequenee is 3%. In this model, using3% dilute Gd instead of 4% for IR-TrueFlSP catheter traekingwill limit the amount of Gd exposure without a statistieallysignifieant loss in SNR and simplify an endovaseularproeedure employing both sequenees. These results shouldbe a guide for further interventional MR studies using IR­TrueFISP.

Poster No. 303

Imaging of Lesions Mimicking Pulmonary ArteriovenousMalformations.R.P. Chan, St. Michael 's Hospital, University ofToronto,Toronto, ON, Catwda • M. E. Faughnan • R. Hyland

PURPOSE: To identify lesions mimieking pulmonaryarteriovenous malformations (PAVMs) during imagingevaluation of patients with known or suspeeted HereditaryHemorrhagie Telangiectasia (HHT).

MATERlALS AND METHODS: A retrospeetive ehart reviewof patients referred to a tertiary eare aeademie eenterspecializing in the diagnosis, sereening and management ofPAVMs and HHT was performed. Patients referred withpulmonary lesions suspeeted initially as representing PAVMs,whieh were subsequently shown not to be, were identified,

S104 and their irnaging, including chest radiography (CXR), eontrast

eehocardiography (CE), computed tomography (CT), andpulmonary angiography (PA), was analyzed.

RESULTS: Atotal of 7 patients (5 female, 2 male; mean age41 years) with lung lesions suspected to represent PAVMsbased on initial imaging were identified. Iwo patients had aknown clinieal diagnosis of HHT. Ali patients were imagedwith CXR, CE, and CT, and 5 patients underwent PA. CXRwas abnormal in 4 patients (l nodule, 3 tubular lesions). CEdemonstrated shunting in 4 patients (3 intrapulmonary, 1intraeardiae). 5 patients required both CT and PA to excludePAVM, whereas CT alone was able to make an alternatediagnosis in 2 patients. Diagnoses of puJmonary lesionsmimicking PAVM were as follows: inflammatory lung diseasewith "tree-in-bud" pattern (I), pulmonary nodule (2), partialanomalous pulmonary venous return (l), mucous plug due toendobronehial eareinoid tumor (I), pulmonary sear (l), normaltortuous vessel (I).

CONCLUSION: The diagnosis and endovaseular treatmentof PAVMs is important in preventing serious eomplieationssueh as stroke, brain abseess, hemoptysis and hemothorax. Anumber ofentities ean mimie PAVMs on initial imaging studies,and therefore an awareness of them is importanŁ. CT, eitheralone, or in eombination with PA, is helpful in the evaluationof these lesions. Correlation with elinieal history and CE isimportanŁ. PA remains the gold standard in excluding PAVM.

Poster No. 304

How Does Location of Venous Malformation AffectChanges in Pulmonary Pressure after EthanolEmbolization?S.E. Mitchell, Johns Hopkins Medical Institutions,Baltimore, MD, USA. A.M. Shah

PURPOSE: Beeause of the morbidity reported speeifieallywith ehest wall venous maltormation (VM) ethanolembolization, we eondueted this study to determine if aparticular loeation of a VM is assoeiated with more ethanoltoxieity than another.

MATERIALS AND METHODS: We performed ethanolembolization proeedures in patients with VMs. Pulmonaryartery (PA) blood pressures (BP) were eontinuously monitoredfor the entire proeedure. We noted PA BP immediately beforeand after ethanol injeetions. For analytieal purposes, westratified the proeedures performed aeeording to the loeationof lesion on the body. Linear regression analysis wasperformed to look at factors affecting PA BP ehanges indifferent loeations.

RESULTS: In the upper extremity, 1 mmHg rise in systemicBP during the injeetion led to O.OSmmHg rise in PA BP(p=O.OS). Volume of ethanol was not a signifieant predictor ofehange in PA BP in this loeation. In the lower extremity,having adjusted for amount ofethanol, ImmHg rise in systemieBP led to 0.04 mmHg rise in PA BP (p=0.02), and havingadjusted for ehange in systemie BP, Iml of 100% ethanolledto 0.22 mmHg rise in PA BP (p=0.02). In head and neekregion, having adjusted for volume ofethanol, 1 mmHg rise insystemie BP led to inerease in PA BP by O.OSmmHg (p<O.OOI).In trunk region, ImmHg rise in systemie BP led to 0.22 mmHgrise in PA BP (p<O.OOI). Volume of ethanol not a strongpredietor ofPA BP ehange in this region. In pelvis and genitalregion, having adjusted for volume ofethanol, ImmHg rise nsystemie BP led to rise in PA BP by 0.21 mmHg.

CONCLUSION: The PA BP changes analyzed for location ofVM treated were primarily related to changes in systemic BP,especially in the upper extremity, head and neck, chest andabdomen, and pelvis I genitourinary locations. The volume ofethanol given was significantly associated with PA BP changesonly in the lower extremity.

Pulmonary Angiography in the Non-Human Primate.Z. Neem.an, NJH, Bethesda, MD, USA -M.G. Wysoki -J.Bacha - D. Bunnell - BJ. Wood - B. Hirshberg

PURPOSE: To validate a previously undescribed non-human'primate model for evaluation of pulmonary emboli. Non­human primates bear close relationship phylogeneticaJly tohumans, which makes them an ideał model for studying thepathophysiology, treatment and prevention of pulmonaryembolic disease as well as immunomodulatory agents andtherapies, and potentially thrombogenic drugs.

MATERJALS AND METHODS: Thromboembolic events,including evidence of pulmonary emboli, were discovered atautopsy in patients and primates receiving variousimmunomodulatory agents. New immunomodulatory agents(antibodies and receptorfusioD proteins) are specific for humanepitopes, but many cross-react with primate epitopes. Thus,there is a need for a non-Iethal, minimal invasive procedure toidentify the risk of thromboembolic events. The pulmonaryangiographic procedure, including vascular access, catheterused, type and amount of contrast material and imaging usedand intra and post procedurał care were recorded and anałysed.

RESULTS: Monkeys ranged from 3.7 kgs to 7.7 kgs.Pulmonary angiography was perfonned successfully in 6 non­human primates without complication. The images obtainedwere satisfactory to exclude large or or segmental emboli. Inone monkey bilateraI segmental pulmonary emboli weredemonstrated. The model is being further studied as a part ofan ongoing study of immunomodulatory agents used for isletceli transplantation.

CONCLUSION: Pulmonary angiography in non-humanprimates is feasable and safe and can be a useful tool in thepre-cHnical evaluation of any potentially thrombogenic drugor immunomodulatory agent.

Localion

Upper ExlremityLower ExlremityHead and NeckTrunkPelvis and Genitourinary

No. Ol Injeclions (%)

108(9.76)451 (40.78)403(36.44)54(4.88)90(8.14)

Mean Rise in PA BPafter Elhanollnjection(95% ConfidenceInlerval)0.57 (-0.4010 1.54)0.85 (0.4310 1.26)1.2 (0.77 to 1.64)1.0 (-Q.56 to 2.56)1.91 (0.79103.03)

Poster No. 305

Vascular Interventions: PTA/StentlFemoral Hemostasis

Poster No. 306

Treatment oflnnominate and SubcłavianArtery StenosisUsing Endovascular Stents.JA Skinner, Mayo Clinic, Rochester, MN, USA - H.Bjamason - M. McKusick - J.e. Michael - S. Misra - J.e.Andrews, et al.

PURPOSE: Evaluate clinical outcome, patency rate andcomplications from treatrnent of subclavian and innominateartery obstruction using endovascular stents.

MATERJALS AND METHODS: Charts were reviewed for allpatients who underwent subclavian or innominate arterystenting from January 1995 through June 2002. Data collectedincluded presenting symptoms, patient demographics and riskfactors, stent size and location. Complications were identifiedand follow up was obtained.

RESULTS: Atotal of 26 patients were identified, 16 malesand 10 females. The mean age was 66 with a range of 44-82.Twenty one (81 %) of the obstructions were in the leftsubclavian artery, 3 in the right innominate artery and 2 in theright subclavian artery. Eight patients presented with coronaryartery steal, 6 with upper extremity claudication and 6 withsymptoms of vertebral basilar insufficiency. Ten patients hadleft internal mammary artery coronary bypass and one hadright internal mammary artery bypass. One patient had anipsilateral dialysis fistula. Eighteen patients had history oftobacco use. Twenty-five of the 26 cases were technicallysuccessfu!. Subclavian artery dissection complicated twoprocedures. There were 3 significant hematomas, 2 of whichwere from left brachial approaches. There were no strokes.Six patients had follow up ultrasound imaging, all of whichwere norma!. Six patients had repeat angiograms, where of 3had recurrent stenosis. Of these, l patient underwent bypasssurgery and the other two had successful endovasculartreatment

CONCLUSJON: Subclavian and innominate artery stenting isa safe and effective method of treating subclavian arterystenosis. The majority of cases involved the left subclavianartery, and complications were minor with brachial arteryaccess site hematomas being the most common. The long­term clinical outcome is good.

Poster No. 307

Mid-Term Results after Attempted EndovascularReconstruction of the Occłuded Subclavian Artery.M.A. Brecheisen, Kansas University Medical Center,Kansas City, KS, USA - K. Yalavarthi - R. Miller - D.Eckard - T.G. Raveill - P. Johnson

PURPOSE: To retrospectively evaluate results and mid-tennpatency of attempted endovascular reconstruction of elevenpatients with an occluded left subclavian artery.

MATERJALS AND METHODS: Over six years, eleven patients(female, n=4; małe, n=7) with au average age of 63 (range 39­81 years) underwent attempted endovascular reconstructionof an occluded left subclavian artery. The patients presentedwith vertigo, syncope, and/or ann claudication. The diagnosisof left subclavian artery occlusion was established withconventional arteriography. Most occlusions were traversedfrom the upper extremi ty via the brach.ial artery with a stiffhydroph.iljc wice, folIowed by angioplasty and stenting. AUpatients were heparinized during the procedure and placed onaspirin and anti-platelet therapy afterwards. Stent patency

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