Amniocentesis needle with improved sonographic visibility.

Abstract

A new aminocentesis needle was developed to be more clearly depicted during sonographic monitoring. Side holes in the aspiration cannula are designed to reduce the number of "dry" taps. The diameter of each side port approaches the wavelength of a standard 3.5-MHz beam, making the needle shaft more easily imaged with real-time ultrasound. The spherical wavefront of isotropic diffraction is clearly seen, even outside the transducer focal plane.