950-94 Real-time Three-dimensional Intracoronary Ultrasonography: High Resolution Dynamic Images of Coronary Artery Lesions

Intravascular ultrasound displays coronary arteries in independent crosssectional images with no axial information. Three-dimensional reconstruction is mandatory, but cardiac cycle linked vessel motions and torsions of the arteries do not allow to apply simple devices that are used for peripheral vessels. Methods and results: We used a 2.9 F 30 MHz intravascular imaging system in combination with a motorized catheter pullback device. ECG and respiration triggering was performed and cubic datasets were acquired with a time resolution of 25 frames/s. Axial increments were set at 0.1 mm over a distance along the vessels of 25 to 35 mm. After processing the original registrations, three-dimensional real-time images could be created in any plane through the dataset. 25 patients with coronary artery disease were investigated before and after therapeutic interventions including Palmaz-Schatz stents (n = 6), laser angioplasty (n = 5), directional atherectomy (n = 41, and balloon angioplasty (n = 21). The system provided excellent images in all patients. Since the spatial geometry of the stents was known the reliability of the three-dimensional images could easily be proven. Dissection membranes, plaques and vessel takeoffs were clearly visualized in their spatial orientation, and the effect of interventions could be demonstrated in all cases. Major problems arise from tortuous vessels with regionally reduced original image quality and from surface definitions by user dependent settings of the noiselthreshold level. Conclusion Real-time three-dimensional reconstruction of the coronary arteries is possible and extends future application of intravascular sonography.