First-in-human imaging using a MR-compatible e4D ultrasound probe for motion management of radiotherapy.

Purpose: Respiration-induced tumor or organ positional changes can impact the accuracy of external beam radiotherapy. Motion management strategies are used to account for these changes during treatment. The authors report on the development, testing, and first-in-human evaluation of an electronic 4D (e4D) MR-compatible ultrasound probe that was designed for hands-free operation in a MR and linear accelerator (LINAC) environment.

Reconfigurable mosaic annular arrays.

Mosaic annular arrays (MAA) based on reconfigurable array (RA) transducer electronics assemblies are presented as a potential solution for future highly integrated ultrasonic transducer subsystems. Advantages of MAAs include excellent beam quality and depth of field resulting from superior elevational focus compared with 1-D electronically scanned arrays, as well as potentially reduced cost, size, and power consumption resulting from the use of a limited number of beamforming channels for processing a large number of subelements. Specific design tradeoffs for these highly integrated arrays are discussed in terms of array specifications for center frequency, element pitch, and electronic switch-on resistance.

7.5-MHz Pediatric Phased Array Transesophageal Endoscope.

This work extends the clinical benefits of phased array transesophageal echocardiography with high detail and contrast resolution to include neonatal patients. We have built several prototype, 64-element, 7.5-MHz phased array transducers housed in 6.