Improved bolus localization for videodensitometry

摘要

Abstract: Videodensitometric measurement of blood flow requires injection of spatially varying contrast density with minimal perturbation of the flow. Constant injection does not yield sufficient spatial gradients for flow measurement during peak flow and diastole, whereas pulsed injection superposes a time- varying perturbation on the measured flow. In order to avoid these drawbacks, we propose to pre-load the catheter injection tubing with spatially varying contrast density. This allows us to generate spatially localized contrast profiles in phantoms and to inject temporally varying contrast profiles in vivo without pulsatile injection. In phantom experiments we obtain better spatial localization of bolus using pre-loading than by pulsed injection of pure contrast material. Preliminary results indicate improvement in accuracy of blood flow measurements using pre-loaded bolus. !8