Thermal diffusivity and perfusion constants from in vivo MR-guided focussed ultrasound treatments: a feasibility study.
Int J Hyperthermia
; 34(4): 352-362, 2018 06.
Article
en En
| MEDLINE
| ID: mdl-28595499
ABSTRACT
PURPOSE:
This study investigates the feasibility of non-invasively determining thermal diffusivity (α) and the Pennes perfusion parameter (w) from pre-clinical and clinical magnetic resonance-guided focussed ultrasound (MRgFUS) temperature data. MATERIALS ANDMETHODS:
Pre-clinical MRgFUS experiments were performed in rabbit muscle (N = 3, 28 sonications) using three-dimensional MR thermometry. Eight sonications were made in a clinical QA phantom with two-dimensional thermometry. Retrospective property determination was performed on clinical uterine fibroid (N = 8, 9 sonications) and desmoid tumour (N = 4, 7 sonications) data. The property determination method fits an analytical solution to MRgFUS temperatures in the coronal MR plane, including all temperatures acquired during heating and one cooling image. When possible, additional cooling data were acquired for property determination.RESULTS:
Rabbit α and w from Heating Data (α = 0.164 mm2s-1, w = 7.9 kg m-3 s-1) and Heating and Cooling Data (α = 0.146 mm2s-1, w = 3.3 kg m-3 s-1) were within the range of gold-standard invasive measurements, with >50% reduction in variability by including cooling data. QA phantom property determination with cooling data yielded properties within 3% of expected values (α = 0.144 mm2s-1, w = 0.0 kg m-3 s-1), a difference that was not statistically significant (p = 0.053). Uterine fibroid (Heating Data α = 0.212 mm2s-1, w = 11.0 kg m-3 s-1) and desmoid tumour (Heating & Cooling Data α = 0.245 mm2s-1, w = 4.7 kg m-3 s-1) properties are feasible but lack independent verification.CONCLUSIONS:
Thermal diffusivity and the Pennes perfusion parameter can be obtained from in vivo data and with clinical MRgFUS protocols. Property values are consistently improved by including cooling data. The utility of this property determination method will increase as clinical protocols implement improved temperature imaging.Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Fibromatosis Agresiva
/
Ultrasonido Enfocado de Alta Intensidad de Ablación
/
Leiomioma
Tipo de estudio:
Guideline
Límite:
Animals
/
Female
/
Humans
Idioma:
En
Revista:
Int J Hyperthermia
Asunto de la revista:
NEOPLASIAS
/
TERAPEUTICA
Año:
2018
Tipo del documento:
Article
País de afiliación:
Estados Unidos