Eb. Hutchinson et K. Hynynen, Intracavitary ultrasound phased arrays for prostate thermal therapies: MRIcompatibility and in vivo testing, MED PHYS, 25(12), 1998, pp. 2392-2399
Citations number
25
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Medical Research Diagnosis & Treatment
A 62 element MRI-compatible linear phased array was designed and constructe
d to investigate the feasibility of using transrectal ultrasound for the th
ermal therapeutic treatment of prostate cancer and benign prostatic hyperpl
asia. An aperiodic design technique developed in a previous study was used
in the design of this array, which resulted in reduced grating lobe levels
by using an optimized random distribution of unequally sized elements. The
element sizes used in this array were selected to be favorable for both gra
ting lobe levels as determined by array aperiodicity and array efficiency a
s determined by width to thickness ratios. The heating capabilities and MRT
compatibility of the array were tested with in vivo rabbit thigh muscle he
ating experiments using MRI temperature monitoring. The array produced ther
apeutic temperature elevations in vivo at depths of 3-6 cm and axial locati
ons up to 3 cm off the central axis and increased the size of the heated vo
lume with electronic scanning of a single focus. The ability of this array
to be used for ultrasound surgery was demonstrated by creating necrosed tis
sue lesions in vivo using short high-power sonications. The ability of the
array to be used for hyperthermia was demonstrated by inducing therapeutic
temperature elevations for longer exposures. Based on the acoustic and heat
ing performance of this array, it has the potential to be clinically useful
for delivering thermal therapies to the prostate and other target volumes
close to body cavities. (C) 1998 American Association of Physicists in Medi
cine. [S0094-2405(98)01812-4].