Monitoring prostate thermal therapy with diffusion-weighted MRI.
For MR-guided minimally invasive therapies, it is important to have a repeatable and reliable tissue viability evaluation method. The use of diffusion-weighted MRI (DWI) to evaluate tissue damage was assessed in 19 canine prostates with cryoablation or high-intensity ultrasound (HIU) ablation. The apparent diffusion coefficient (ADC) trace value was measured in the treated tissue immediately upon the procedure and on the posttreatment follow-up. For the acute lesions, the ADC value decreased to (1.05+/-0.25)x10(-3) mm2/s, as compared to (1.64+/-0.24)x10(-3) mm2/s before the treatment. There was no statistical difference between previously frozen or previously ultrasound-heated lesions in terms of the 36% ADC reduction (P=0.66). The ADC decrease occurred early during the course of the treatment, which appears to complicate DWI-based thermometry. Over time, the ADC value increased as the tissue recovered and regenerated. This study shows that DWI could be a promising method to monitor prostate thermal therapies and to provide insight on tissue damage and tissue remodeling after injury.
Department of Electrical Engineering, Stanford University, Stanford, California 94305-5488, USA. jeanchen@stanford.edu
Jing
J
Chen
Bruce L
BL
Daniel
Chris J
CJ
Diederich
Donna M
DM
Bouley
Maurice A A J
MA
van den Bosch
Adam M
AM
Kinsey
Graham
G
Sommer
Kim Butts
KB
Pauly
D000818:Animals; D017679:Cryotherapy; D038524:Diffusion Magnetic Resonance Imaging; D004285:Dogs; D007091:Image Processing, Computer-Assisted; D053783:Magnetic Resonance Imaging, Interventional; D008297:Male; D011467:Prostate / Q000473:pathology*; D014464:Ultrasonic Therapy