3-DIMENSIONAL ULTRASOUND IMAGING OF THE ATRIAL SEPTUM - NORMAL AND PATHOLOGICAL ANATOMY

Objectives. This study investigated the feasibility of producing three dimensional gray scale ultrasound images of the atrial septum to demo nstrate normal and pathologic anatomy. Background. Two dimensional ech ocardiography is the principal technique used for imaging the atrial s eptum. Although the diagnostic accuracy of two dimensional echocardiog raphy is high, its capability for displaying complex three-dimensional relations is limited. Methods. Three dimensional ultrasound images we re reconstructed from tomographic images obtained during routine trans esophageal echocardiographic examinations. Custom made semiautomatic a lgorithms for image enhancement, interpolation and segmentation were u sed to produce volumetric gray scale images. Volume-rendered displays of the atrial septum were generated for analysis. Sequential three dim ensional images were generated through the cardiac cycle and displayed cinematographically to permit assessment of motion. Results. The thre e dimensional images obtained from six patients clearly demonstrated n ormal and pathologic anatomy of the atrial septum, including atrial se ptal defects, atrial septal aneurysm and aortic valve ring abscess. Th e images could be manipulated electronically to demonstrate spatial re lations and internal structural details. Conclusions, Three-dimensiona l gray scale reconstruction of ultrasound images obtained by transesop hageal echocardiography is feasible. These images clearly demonstrate anatomic details and spatial relations. The gray scale images may be i nteractively manipulated to optimize the clinician's visualization of the atrial septum and its associated pathologic conditions.