Abstracts S45

provements in its image resolution and analysis capability are requiredbefore it can become a truly versatile and indispensible imaging mo-dality.

0337

Assessment of Thoracic Aortic Atherosclerosis Using Real Time3D Transesophageal EchocardiographyToshio Honda, Sadamoto Hospital, JapanKazuhiko Sadamoto, Sadamoto Hospital, JapanKatsuji Inoue, Ehime University Hospital, JapanHideki Okayama, Ehime University Hospital, JapanJitsuo Higaki, Ehime University Hospital, Japan

Background and Purpose: Two-dimensional transesophagealechocardiography(2D TEE) is a useful method for evaluating thoracicaortic atherosclerosis. However, real time three-dimensional trans-esophageal echocardiography(3D TEE) technique has been recentlydeveloped and is not widely used for evaluating thoracic aortic athero-sclerosis yet. The aim of this study is to assess whether the real time 3DTEE method is useful for evaluating thoracic aortic atherosclerosis ornot.Methods: TEE was performed on 44 ischemic stroke patients (26males, 18 females). We evaluated plaque thickness, mobile plaque andulcer formation using 2D and real time 3D methods. We measured thesize of mobile lesion and ulceration, and calculated the volume ofmobile plaque and ulceration with 3D volume analysis(stacked con-tours method).Results: Mobile plaque was observed in 4 patients and ulcer formationin 3 patients. Plaque thickness over 4 mm was observed in 19 patients.It was possible to measure the size of mobile lesion and ulcer usingboth 2D and 3D TEE images. However, it was possible to calculate thevolume of mobile lesion and ulcer only from 3D TEE images.Conclusions: Real time 3D TEE method is useful to assess thoracicaortic atherosclerosis, particularly the volume analysis of mobileplaque and ulceration.

0338

Comparative Value of 3D and TransesophagealEchocardiography in the Pre-Surgical Assessment of Patientswith Mitral RegurgitationZhian Li, Beijing Anzhen Hospital, ChinaXiaoyan Gu, Beijing Anzhen Hospital, Capital University of MedicalSciences, ChinaYihua He, Beijing Anzhen Hospital, Capital University of MedicalSciences, ChinaMichael C Kontos, Virginia Commonwealth University, Richmond,United StatesJ V Ian Nixon, Virginia Commonwealth University, Richmond,United States

Objective: We sought to determine the feasibility and accuracy of the3D transthoracic (3D-TTE)echocardiography compared with 2D trans-esophageal (2D-TEE) and 2D transthoracic(2D-TTE)echocardiographyusing surgical findings as gold standard.Methods: Patients (pts) with moderate to severe MR referred for MVsurgery underwent both preoperative TEE and 3DE studies. Findings ofTEE and 3DE were compared those found at surgery, using the no-menclature Carpentier.Results: A total of 93 pts were studied to localize mitral pathology andregurgitation defects. Findings include: normal leaflet motion (n�12),excessive motion of a MV leaflet (n�53) and restricted motion of anMV leaflet (n�28). As each MV has six sections, a total of 558 mitralsections were evaluated. Defect location agreement between the TEE

and surgical findings was 91%, and between the 3DE and surgical

finding was 95%. 3DE can describe the eccentrically directed regurgi-tant jet and multi-jets regurgitation, obtain qualitative analyses of MRseverity. 3DE can accurately measure ERO, MV area, annular circum-ference and tenting volume. Mean ERO was (0.39�0.30 cm2) andannular circumference was (8.0�2.0 cm).Conclusions: 3DE appears to provide similar and in some cases is asuperior diagnostic non-invasive evaluation tool compared with TEEregarding the etiology and extent of MR, possibly obviating the needfor TEE prior to MR surgery.

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Volume Imaging in Abdomen, Can it Work?Stephanie Wilson, University of Calgary, Canada

Traditionally, data storage for abdominal ultrasound has included areliance on single frames often supported by short video clips ofportions or all of an examination. It is well recognized, however, thatwhile single images might show an aspect of pathology, single imagesoften fail to show adequately the entire picture and also the relation-ships of the pathology. Today, the acquisition of a volume of ultra-sound data may be performed freehand or by a mechanically drivenmulti-element array transducer which has the ability to acquire a dataset by sweeping the array through a pre-determined angle of acquisitionduring a breath hold. The volumetric data set results from the combi-nation of the information through each plane of the sweep. Multi planarreconstruction (MPR) will then allow for the creation of image planes,which are at unique and often unattainable angles.Our success with volumetric acquisition includes adherence to proto-cols for performance for each organ including: a prescan, to guide theplacement of the transducer, determine the patient position, and theangle for the acquisition; the volume acquisition itself; a volumereview; and an additional scan to include any missed components in thevolume data set.In our own data, the kidneys were the most successful organs studiedbut all abdominal organs provided good success with excellent multi-planar imaging and the additional benefit of multiple planes of real timedata for review. Infrequent failures for the liver related to obesity andcirrhosis in some situations. Current technical limitations relate to themechanical acquisition with loss of resolution outside of the acquisitionplane.

0340

3D Ultrasound of the Upper AbdomenOdd Helge Gilja, National Centre for Ultrasound inGastroenterology, Norway

The digital revolution has made three-dimensional (3D) ultrasonogra-phy a natural extension of 2D ultrasound scanning. This lecture reviewssome of the principles and methods in 3D ultrasonography of the upperabdomen. At present, the process of making 3D images based onultrasonography is commonly divided into 5 steps: Data acquisition,data digitization, data storage, data processing, and data display. Prin-cipally, data acquisition by 3D ultrasonography can be performed in 3different ways; either by using a 2D probe attached to a motor whichmoves the probe in a computer-defined way or by a spatial localizingsystem connected to a 2D probe or by genuine, electronic 3D probeswith the possibility of direct volume acquisition in real time. Truevolumetric 2D array transducers instantly generate a volume of ultra-sound data, enabling dynamic 3D ultrasonography.A critical step in processing of 3D data is segmentation, which is theprocedure where the object of interest is separated from the surround-ing structures. Three fundamental approaches to segmentation havebeen utilised in 3D ultrasonography: Extraction by visual inspection

and manual outlining of contours; semi-automatic separation using