Assessment of tumor response to oxygen challenge using quantitative diffusion MRI in an animal model

作者：Zhang Zhongwei^*; Yuan Qing; Zhou Heling; Zhao Dawen; Li Li; Gerberich Jenifer L; Mason Ralph P

来源：Journal of Magnetic Resonance Imaging, 2015, 42(5): 1450-+.

DOI：10.1002/jmri.24914

• diffusion-weighted imaging
• intravoxel incoherent motion (IVIM)
• stretched-exponential model
• perfusion
• tumor oxygenation
• hyperoxia

PurposeTo assess tumor response to oxygen challenge using quantitative diffusion magnetic resonance imaging (MRI).
Materials and MethodsA well-characterized Dunning R3327-AT1 rat prostate cancer line was implanted subcutaneously in the right thigh of male Copenhagen rats (n=8). Diffusion-weighted images (DWI) with multiple b values (0, 25, 50, 100, 150, 200, 300, 500, 1000, 1500 s/mm(2)) in three orthogonal directions were obtained using a multishot FSE-based Stejskal-Tanner DWI sequence (FSE-DWI) at 4.7T, while rats breathed medical air (21% oxygen) and with 100% oxygen challenge. Stretched-exponential and intravoxel incoherent motion (IVIM) models were used to calculate and compare quantitative diffusion parameters: diffusion heterogeneity index (), intravoxel distribution of diffusion coefficients (DDC), tissue diffusivity (Dt), pseudo-diffusivity (Dp), and perfusion fraction (f) on a voxel-by-voxel basis.
ResultsA significant increase of (73.94.7% in air vs. 78.1 +/- 4.5% in oxygen, P=0.0198) and a significant decrease of f (13.4 +/- 3.7% in air vs. 10.4 +/- 2.7% in oxygen, P=0.0201) were observed to accompany oxygen challenge. Correlations between f and during both air and oxygen breathing were found; the correlation coefficients (r) were -0.90 and -0.96, respectively. Positive correlations between Dt and DDC with oxygen breathing (r=0.95, P=0.0003), f and DDC with air breathing were also observed (r=0.95, P=0.0004).
ConclusionQuantitative diffusion MRI demonstrated changes in tumor perfusion in response to oxygen challenge. J. Magn. Reson. Imaging 2015;42:1450-1457.

• 出版日期2015-11