On the correlation between the water diffusion coefficient and oxygen tension in RIF-1 tumors

✍ Scribed by Karl G. Helmer; Sam Han; Christopher H. Sotak

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 248 KB
• Volume: 11
• Category: Article
• ISSN: 0952-3480
• DOI: 10.1002/(sici)1099-1492(199805)11:3<120::aid-nbm506>3.0.co;2-#

✦ Synopsis

Water diffusion-coefficient mapping was used in conjunction with F inversion-recovery echo-planar imaging (IR-EPI) of a sequestered perfluorocarbon (PFC) emulsion to investigate the spatial correlation between the diffusion coefficient of water and the tissue oxygen tension (pO 2 ) in radiation-induced fibrosarcoma (RIF-1) tumors (n = 11). The diffusion-time-dependent apparent diffusion coefficient, D(t), was determined by acquiring diffusion coefficient maps at 20 different diffusion times. Maps at four representative time points in different regions of the D(t) curve were selected for final analysis. An intravenously administered PFC emulsion, perfluoro-15-crown-5-ether, was used to generate the pO 2 maps. D(t) and pO 2 data were acquired with the animal breathing either air or carbogen (95% O 2 -5% CO 2 ) to investigate the effects of increased tumor pO 2 on D(t). The average increase in tumor pO 2 was 22 torr when the breathing gas was changed from air to carbogen. Correlation plots generated from pixel data for D(t) (air breathing) vs D(t) (carbogen breathing) show little deviation from a slope of unity. Correlation plots of D(t) vs pO 2 indicate that no correlation is present between these two parameters. This study also confirmed that necrotic tissue was best differentiated from viable tumor tissue based on D(t) maps at long diffusion times.