DIAGNOSIS OF CONGENITAL HEART DEFECTS BY MEANS OF TRANSTHCRACIC 3-DIMENSIONAL ECHOCARDIOGRAPHY WITH A COMPUTED TOMOGRAPHY IMAGING PROBE |[lpar]|ECHO-CT|[rpar]|

摘要

A prototype tomographic ultrasound system: Echo-CT was evaluated 71 patients aged 4 days to 17 years with normal heart (n=1), ventricular septal delect (n=14), subaortic stenosis (n=10), mitral valve anomalies (n = 9), atrioventricular septal defect (n = 3), acrtic stenosis (n = 5), atrial septal defect (n=4) and various other congenital heart defects (n=20). The transducer is a 5 Mhz device with G4 elements mounted on a sliding carriage. The transducer is driven by a computer-controlled stepper motor in steps of .5-1.3 mms and acquires parallel tomographic slices of the head perpendicular to the position of the probe. The transducer moves from the outflow tract to the cardiac apex. With ECG and respiration gating a complete cardiac cycle is recorded at each tomographic level. 50 to 130 slices per patient wore acquired. Position of the probe on the chest varied in each patient. In 7 newborns the probe was used from the subcostal position. Image acquisition took 3-7 minutes. Data arc stored as three-dimensional datasels in the imaging computer. Out of those data sets up to 5 different two-dimensional views in different planes can be constructed, so that the heart can be viewed from multiple planes without changing the probe position on the chest. In all but 2 patients wo could also reconstruct the heart three-dimensionally from different views, which look 20-90 minutes per patient. Views similar to the ones a surgeon has at operation can be genenerated. We conclude that this preliminary study demonstrates the feasibility of the tomographic three-dimensional reconstruction technique, which yields additional information on the morphology of septal defects, tricuspid, mitral and aortic valves and complex malformations.