International Workshop on Medical Ultrasound Tomography

First steps towards the Delft Breast Ultrasound Scanning System (DBUS)

Nov 2, 2017, 9:50 AM

20m

Lecture Hall

Oral Main Track Session 5: Ultrasound tomography systems

Speaker

Koen van Dongen (Delft University of Technology)

Description

Ultrasound is gaining interest as a modality to scan for tumors in dense breasts of young women. Tissue characterisation by full wave form inversion (FWI) has the potential to improve the accuracy of breast ultrasound. However, many of the existing systems use frequencies above 1 MHz. With these high frequencies it is difficult to apply FWI due to the computational costs involved. Consequently, we investigate the applicability of low frequencies together with FWI for breast cancer detection.

(4) Discussion and Conclusion

A flexible two-dimensional low-frequency ultrasound scanner has been developed. The system has successfully scanned agar based phantoms. Currently, we are optimizing the system. The next step will be to use the data to test the applicability of FWI as a means for improved breast cancer detection.

(2) Material and Methods

Due to the absence of flexible low-frequency scanning devices suitable for FWI, we have built our own two-dimensional circular scanning system. The system contains two 0.5 MHz transducers. The source is connected to an arbitrary waveform generator. The position of the source is “fixed”; only the radius to the centre of the system can be varied manually. The receiver is connected to a 400 MHz 14 bit A/D converter. To rotate the object and the receiver independently we use two rotating motors. The receiver’s radius to the centre of the system can be varied manually as well.

(3) Results

To test the system, several scans have been made and processed using SAFT. Currently, various “artefacts” present in the data, e.g. mechanical “cross”-coupling, are being investigated and eliminated. A two-dimensional scan of an agar based phantom has been made publically available on the USCT Data Exchange and Collaboration Website (http://ipeusctdb1.ipe.kit.edu/~usct/challenge/) so that the entire USCT community can take advantage of our system.