ABSTRACT
Objective To acquire volume rendered images of left atrial appendage ( LAA ) chambers by three dimensional transesophageal echocardiography (3DTEE) using a novel image mode of grey values inverted imaging ( GVI) . Methods Forty patients with atrial fibrillation were performed with TEE and cardiac CT examination before intervention treatment . Three‐dimensional transesophageal echocardiography images were acquired and displayed as a gray values inverted mode . Threshold segmentation and interactive segmentation were used to 3D digital replicas of LAA chambers . Morphology information including morphology type of LAAs and number of lobes and measurements of LAAs were recorded and compared with CT volume reconstruction(CT‐VR) images .Results Morphology information and measurements were successfully acquired by CT and 3DTEE‐GVI images in all 40 cases . The consistence of LAA morphology type by 3D‐GVI and CT was 97 .5% . The consistence of number of LAA lobes by 3D‐GVI and CT was 92 .5% . The measurements of long axis ,short axis ,area of ostiums of LAAs ,and depth of LAAs by CT were larger than those by 3D‐GVI ( P < 0 .01 ) . There were agreements between two methods of measurement . Conclusions LAA chambers can be reconstructed by 3D TEE‐GVI ,which can achieve similar effect to CT‐VR . 3DTEE‐GVI promises to be one of the most effective methods in assessment of LAAs′morphology information for planning of LAA occlusion .
ABSTRACT
STATEMENT OF PROBLEM: Initial stability of implant is an important factor for predicting osseointegration. It requires a rapid, non-invasive, user-friendly technique to frequently assess the implant stability and the degree of osseointegration. PURPOSE: The aim of this study was to evaluate the correlation between the resonance frequency analysis (RFA) and the radiographic method for peri-implant bone change under in vitro conditions. MATERIAL AND METHOD: Twenty implants of 3.75 mm in diameter(Neoplant, Neobiotech, Korea) were used. To simulate peri-implant bone change, 2 mm-deep 45degrees range horizontal defect and 2 mm-deep 90 degrees range horizontal defect area were serially prepared perpendicular to the X-ray beam after conventional implant insertion. Customized film holding device was fabricated to standardize the projection geometry for serial radiographs of implants and direct digital image was obtained. ISQ values and gray values inside threads were measured before and after periimplant bone defect preparation. Results. Within a limitation of this study, ISQ value of resonance frequency analysis was changed according to peri-implant bone change (p0.05). But, in horizontal defect condition, relatively positive correlation were between ISQ and gray values(r=0.663). CONCLUSION: This results provided a possibility that peri-implant bone change may be evaluated by both RFA and radiographic method.