Intravascular ultrasound Doppler measurement of blood flow velocity

Background and Purpose. The authors investigated the feasibility and accura cy of intravascular Doppler sonography (IVDS) with a newly developed microp robe. Methods. The known method to determine blood Row velocity by transcut aneous Doppler sonography was transferred to an intravascular usable Dopple r probe. With the improved technique, a microprobe measuring 0.3 mm in diam eter can be advanced through a 5F catheter used in routine diagnostic angio graphy to perform intravascular Doppler sonography. In a first step, the co nditions for application and measurement were studied in a Row tube model a nd were transferred in a second step to patients undergoing routine angiogr aphy and patients with arterial stenoses. Results. Measurements with nondeg assed liquids showed a high intensive acoustic signal, but no echo effect c ould be recorded in degassed liquids. IVDS of healthy vessels in 40 patient s showed the same typical Row pulse curve as seen in transcutaneous measure ments. The optimal position of the microprobe with respect to the contact o f the vessel wall, the diastolic and systolic phase, and the distance to th e tip of the catheter could be evaluated. In 95.6% of the 40 patients with healthy vessels, IVDS was successful. Fourteen patients with arterial steno tic diseases were investigated before and after percutaneous transluminal a ngioplasty, and the results of these investigations correlated well with th e angiographical results. Conclusions. For percutaneously directly reachabl e vessels, the transcutaneous Doppler sonography is the choice for easy non invasive and inexpensive measurement of blood Row velocity. However, for ve ssels that are difficult or impossible to reach percutaneously, intravascul ar measurement is a valid procedure.