Three-dimensional sonographic features of a fetus with Wolf-Hirschhorn syndrome

Fabrication of 2-D Capacitive Micromachined Ultrasonic Transducer (CMUT) Array through Silicon Wafer Bonding

Capacitive micromachined ultrasound transducers (CMUTs) have broad application prospects in medical imaging, flow monitoring, and nondestructive testing. CMUT arrays are limited by their fabrication process, which seriously restricts their further development and application. In this paper, a vacuum-sealed device for medical applications is introduced, which has the advantages of simple manufacturing process, no static friction, repeatability, and high reliability. The CMUT array suitable for medical imaging frequency band was fabricated by a silicon wafer bonding technology, and the adjacent array devices were isolated by an isolation slot, which was cut through the silicon film. The CMUT device fabricated following this process is a 4 × 16 array with a single element size of 1 mm × 1 mm. Device performance tests were conducted, where the center frequency of the transducer was 3.8 MHz, and the 6 dB fractional bandwidth was 110%. The static capacitance (29.4 pF) and center frequency (3.78 MHz) of each element of the array were tested, and the results revealed that the array has good consistency. Moreover, the transmitting and receiving performance of the transducer was evaluated by acoustic tests, and the receiving sensitivity was −211 dB @ 3 MHz, −213 dB @ 4 MHz. Finally, reflection imaging was performed using the array, which provides certain technical support for the research of two-dimensional CMUT arrays in the field of 3D ultrasound imaging.

HDlive imaging of the face of fetuses with autosomal trisomies

BACKGROUND

Our objective is to present our experience of facial dysmorphism reconstructed employing conventional three-dimensional (3D) ultrasound and HDlive in fetuses with autosomal trisomies.

METHODS

Seven fetuses with autosomal trisomies (one case of trisomy 13, three of trisomy 18, and three of trisomy 21) at 16-38 weeks' gestation were studied using 3D ultrasound and HDlive.

RESULTS

In one case of trisomy 21 at 29 weeks and 5 days, upward slanting eyes, a flattened nose, low-set ears, and the corners of the mouth turned down were noted employing HDlive. In the other two cases of trisomy 21, both techniques showed the same facial findings. In one case of trisomy 18 at 27 weeks and 6 days, a small head accompanied by a prominent back portion of the head, low-set ears, a small jaw, upturned nose, narrow eyelid folds, and widely spaced eyes were identified using HDlive. In the other two cases of trisomy 18, HDlive showed more detailed features of the fetal face compared to conventional 3D ultrasound. In the single case of trisomy 13 at 31 weeks and 1 day, cleft lip and close-set eyes were recognized with both 3D ultrasound and HDlive.

CONCLUSION

HDlive can provide clearer facial images than conventional 3D ultrasound. In particular, HDlive is superior to conventional 3D ultrasound for the depiction of eye fissures because of its shadowing effect. HDlive may be a useful diagnostic modality for the antenatal evaluation of subtle fetal facial dysmorphism.