Criteria and scheduling of quality control of B-mode and doppler ultrasonography equipment.

Periodic quality control (QC) for ultrasound scanners checks their overall performance, reducing the risk of inaccurate diagnoses. Data from routine annual QC activity were analyzed to optimize the scheduling and the criteria of further QC programs. Among all the ultrasound scanners (68 transducers) in use at the Regional Medical Department of the Aosta Valley, which are currently tested, 48.

Ultrasound-mediated oxygen delivery from chitosan nanobubbles.

Ultrasound (US) energy combined with gas-filled microbubbles has been used for several years in medical imaging. This study investigated the ability of oxygen-loaded chitosan bubbles to exchange oxygen in the presence or in the absence of US. Oxygen delivery is enhanced by sonication and both frequency and time duration of US affected the exchange kinetics.

Microbubble-mediated oxygen delivery to hypoxic tissues as a new therapeutic device.

Chitosan-coated oxygen microbubbles of average diameter 2.5 mum, narrow size distribution and spherical shape were prepared. A core-shell structure was evidenced by fluorescence microscopy using fluorescent microbubbles.

Doppler indices in the umbilical arteries: influence of vessel curvature induced by bladder filling.

Doppler indices are widely used to assess normal versus pathologic haemodynamics. In obstetrics, the assessment of abnormal values in some critical compartments, such as the umbilical arteries (UA), may be crucial in the clinical management of growth-restricted foetuses. It was recently proposed that the UA should be sampled in their perivesical portion (PVC), i.