INTRAVENOUS ANGIOCARDIOGRAPHY USING DIGITAL IMAGE PROCESSING
Hugo G. Bogren, Joachim H. Bürsch, R. Brennecke, Wolfgang Radtke, F. H. Heintzen · Investigative Radiology · 1981
A simple method was designed to produce ventricular and atrial septal defects (VSD,ASD) in pigs after right ventriculotomy and left atriotomy. After intravenous (IV) injection of 0.5–1 ml Urografin 76% computerized digitization and processing of roentgen video images recorded at a rate of 50/sec was performed. The images were recorded in the 4-chamber view which was obtained by 30° caudocranial angulation and 50° LAO obliquity. The processing of images included ECG-gated background subtraction and rescaling, sometimes histogram equalization and time parameter extraction. Integration of multiple background and multiple contrast images was performed in order to increase the signal-to-noise ratio. The ASD and VSD's could be detected after IV injection of contrast medium and processing of the images. The most useful images were left ventricular end diastolic (LVED), end systolic (LVES), and LV mid systolic, but they could also be detected on right ventricular ED (RVED) minus LVED, RVES minus LVES, LVED minus LVES and on time parameter extraction images. In the 4-chamber view the septum with the VSD could be seen between LV and RV which was opacified via the VSD. In ASD, the septum was seen to be intact between the contrast-filled ventricles while the ASD was seen in the atrial septum. On time parameter extraction images the arrival of contrast medium into RV could be measured to be later than to LV in a VSD. Experiments with created shunts between the aorta and the pulmonary artery will be performed, hopefully before the presentation of this abstract. The results of experiments in pigs are the basis for clinical use of digitized IV angiocardiography, a noninvasive procedure that may be used in outpatients. Supported by Deutsche Forschungsgemeinshaft & G. Weber's Foundation.