32467

The usefulness of three-dimensional ultrasound in visualisationof the collateral circulation in the course of thrombophlebitisStefanczyk L,*1 Mysior M,1 Gorski A,2 1. Ultrasonography, InstitutePolish Mother Memorial Hospital, Lodz, Poland, and 2. VascularSurgery, Medical University, Lodz, Poland

Objective: Visual documentation of ultrasound vascular examina-tions is the major obstacle in the widespread use of sonography asthe “golden standard” in the assessment of thrombophlebitis. Tech-nological progress in the recent years brings hope to change thissituation. The usefulness of the 3-D option in visualisation of thevenous collateral circulation in the course of thrombophlebitis wasanalysed in the paper.Methods: Materials comprise 88 color Doppler examinations in 50patients registered in 3-D technique. The lesions were documentedin the iliac and femoro-popliteal segments. The examinations wereperformed in all stages of the disease: acute, chronic, and post-thrombotic syndrome. At most, 3 examinations of one patients areincluded in the study. GE Logic 500 Pro with 3– 6 MHz Convex (foriliac segment) and 4 –9 Linear (for extremity) probes were used. Theacquisition of data was done in perpendicular planes to the axis ofa vessel. Consecutive images were collected by the popular graphicsoftware Corel.Results: The collateral circulation is particularly favourable for 3-Dvisualisation due to relatively high and continuous flow. In the abdom-inal cavity, the formation of images poses more difficulties because ofmotion artifacts, bowel gases, pulsation of large vessels, and peristalticmovements. The examination of extremities is easier, since vessels aresituated more superficially. The utilised method is able to producepseudoangiographic images of collateral circulation up to 20 cm inlength.Conclusions: The 3-D option rarely helps the examiner in the inter-pretation of the images, but is an effective form of scientific documen-tation making communication between the examiner and the clinicianeasier.

32470

Genetic ultrasound: Influence of fetal gender in detection rate ofsonographic soft markersAcosta R,1 Taslimi MM,*1 Hudgins LA,2 El-Sayed Y,1 Druzin M,1

Chitkara U,1 1. Obstetrics and Gynecology. Division of Maternal-Fetal Medicine, Stanford University Medical Center, Stanford, CA,and 2. Pediatrics, Division of Medical Genetics, Stanford UniversityMedical Center, Stanford, CA

Objective: The aim of this study was to determine the influence of fetalgender in detection rate of soft markers (SM) on second-trimestergenetic ultrasound (US).Methods: From 3/1994 to 2/2002, all amniocentesis performed in ourcenter, between 15–23 weeks GA, positive for T-21, T-18, or T-13were identified. Reports and images were reviewed for presence of:nuchal fold, choroid plexus cyst, mild ventriculomegaly (10–15 mm),echogenic intracardiac focus, pelviectasis, two-vessel cord, echogenicbowel, short femur, and short humerus. Fetal gender was confirmed bykaryotype. Statistical analysis was done by Fisher’s exact test.Results: 148 (93%) of 160 records were complete and analyzed. 78fetuses were males and 70 females. SM were identified in 61 (41.2%);39/110, 14/28, 8/10 in T-21, T-18, and T-13, respectively. Of these SM,

40 (65.6%) were identified in males and 21 (34.4%) in females,p�0.01. Similar trend for a higher incidence in males vs. femalespersisted when analyzed by type of trisomy: T-21, 69.2%, p�0.07;T-18, 57.1%, p�0.05; and T-13, 62.5%, p�0.44.Conclusions: Soft markers are more likely to be detected on trisomicmale than female fetuses during second-trimester genetic ultrasound,regardless of the type of trisomy. Fetal gender appears to have adefinitive impact on the detection rate of sonographic soft markers forchromosomal abnormalities.

32472

Does tissue harmonic imaging improve target or needleconspicuity of three-dimensional ultrasound for guidance ofinterventional procedures?Rose SC,* Nelson TR, Radiology, University of California, SanDiego, Medical Center, San Diego, CA

Objective: The aim of this study was to determine whether tissueharmonic imagine (THI) improves target or device conspicuity on 3DUS volume rendered (VR) images compared to conventional B-mode3D US VR images.Methods: US phantoms were made using a petroleum gel. Corn starchwas used to vary the echotexture. Three phantoms were created with (1)no starch (hypoechoic), (2) 5 ml of starch (isoechoic), and (3) 15 ml ofstarch (hyperechoic) added. Each phantom had 2-cm diameter hypo-echoic, isoechoic, and hyperechoic gel targets imbedded. Implanteddevices were a 22-gauge needle and a 14-gauge radiofrequency abla-tion probe (shaft and tines) introduced into the background gel at 20and 60 degree inclinations. Identical static 3D US volume data setswere acquired with conventional B-mode and THI mode. VR imagingwas used to display the data set with combinations of 7 different postprocessing display parameters. Conspicuity of the targets and deviceswas judged on a five-point visibility scale. Ratings for THI acquisitionwere compared to B-mode acquisition.Results: Conspicuity of the target lesions and devices varied widely,depending on background and target echotexture. For visualization oftargets, THI improved, made no difference, or worsened conspicuityrelative to B-mode in 15.2%, 56.4%, and 28.8%, respectively. Forvisualization of devices, THI improved, made no difference, or wors-ened conspicuity in 4.4%, 75.6%, and 20.0%, respectively.Conclusions: With respect to 3D US VR imaging for interventionalapplications, THI appears to offer no advantage over conventionalB-mode acquistion.

32477

Is ultrasound-guided radiofrequency ablation indicated formucinous hepatic lesions? Experimental study in extractedbovine liverPark C,* Lee S, Suh S, Kim K, Kim C, Radiology, Korea UniversityGuro Hospital, Seoul, South Korea

Objective: This in vitro study was performed to assess the possibilityof radiofrequency (RF) ablation for mucinous hepatic lesion.Methods: Under ultrasound (US) guidance, 2–12 ml of US gel wasinjected to extracted bovine liver parenchyma to produce ten focalmucinous lesions. After gel injection, US scan showed well-definedfocal lesions, diameter 14–40 mm, with internal echo-free areas. Onecontrol lesion was prepared to evaluate the gross and microscopicfindings of US gel localized in the liver. RF ablation was performed in

Abstracts S183