[A probe holder for improving duplex sonography].
To enable mechanical probe fixation for carotid duplex sonography, a hollow cylinder was mounted to the free end of a snake-neck type surgical instrument holder. A second hollow cylinder fitting over the handpiece of the probe is adapted to its bore. This allow turning of the probe from the longitudinal to the axial plane through the examined vessel, the level of the contact surface and its pressure against the tissue remaining unchanged. The use of this device allows better correlation of vessel cross sections to the respective segments of the vessel as imaged in the longitudinal plane. A further advantage of the probe-holder is that once the position of the probe is selected, it leaves both hands of the examiner free for operating the Doppler system. With duplex equipments programmed for volume flow calculation from cross sectional area and time-averaged mean spatial velocity the feasibility of such measurements is considerably improved.