[Effect of hyperthermia on blood flow in VX2 tumor transplanted in rabbit: evaluation with color Doppler flow imaging and dynamic MR imaging].
Effect of hyperthermia on blood flow was evaluated using VX2 rabbit carcinoma in both legs. Microwave energy at 2450 MHz was used to heat tumors for 40 minutes. An outer cannula of 18 G Erasta was implanted in the depth of 2 cm in tumor to measure the temperature and to maintain at 43.0 degrees C-44.0 degrees C. The blood flow in tumors was evaluated by color doppler flow imaging and dynamic MRI. Disturbance of blood flow in the depth of surface 0 cm to 2 cm in tumors was showed at 10 minutes starting 43.0 degrees C heating and at almost all sites disappearance of blood flow was showed at 40 minutes using color doppler flow imaging. But the blood flow beyond the depth of 2 cm was not so disturbed at 40 minutes, relatively. After hyperthermia T 1 WI and T 2 WI in heated tumor were no difference comparing with those in control tumor, but heated tumor showed no enhancement using dynamic MRI with TURBO-FLASH technique and post-enhanced T1 WI. Histologically, there was extensive tumor necrosis and thrombus formation in heated tumor after 3 days and 1 week. Therefore color doppler flow imaging and dynamic MRI were considered to be useful for evaluation of blood flow in tumor after and during hyperthermia.
Arita
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Department of Radiology, Yamaguchi University School of Medicine.
D000818:Animals; D006979:Hyperthermia, Induced; D008114:Liver Neoplasms, Experimental / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D009368:Neoplasm Transplantation; D011817:Rabbits; D012039:Regional Blood Flow; D014463:Ultrasonography / Q000379:methods