Realization of combined diagnosis/treatment system by ultrasound strain measurement-based shear modulus reconstruction/imaging technique examples with application on the new type interstitial rf electromagnetic wave thermal therapy

Abstract

For various soft tissues (e.g., breast, liver, etc.), we are developing the ultrasonic strain measurement-based shear modulus reconstruction/imaging technique. To clarify the limitation of this technique as a diagnostic tool, together with improving the technique, we are collecting clinical shear modulus images. Furthermore, we are applying the technique as the monitoring technique for the effectiveness of chemical therapy (e.g., anticancer drug, ethanol) and thermal therapy (e.g., rf electromagnetic wave, HIFU, etc.). Here, we showed shear modulus images obtained in quasi-real time. Using a conventional work station, quantitative images were obtained in the order of ten seconds. In particular, by exhibiting the superiority of shear modulus imaging compared with simultaneous B-mode imaging, we delineated the effectiveness of the technique as the clinical visualization technique for diagnosis and therapy. For instance, the shear modulus value of in vivo human breast carcinoma was significantly high (typical value: 6.33 /spl times/ 10/sup 6/ N/m/sup 2/). Shear modulus images were also obtained on in vivo human liver tissues. On the in vitro calf liver, the shear modulus value of an electromagnetic wave-induced thermal lesion became about five times higher after cooling down. We believe that this technique is currently solely available as a diagnosis or monitoring tool, and yet in the near future this technique will allow combined diagnosis/therapy systems for opening up a novel clinical style.