We aimed to quantitatively investigate the alteration of parotid perfusion after irradiation using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) based on a two-compartment tracer kinetic model. This study enrolled 19 patients (53.2 ± 14.9 years) treated by head and neck radiotherapy and 19 age-relevant and sex-matched subjects as a control group. Perfusion parameters (Kel, k21 and A) of parotid glands were analyzed based on the Brix model from T1-weighted DCE-MRI. Suitability of the Brix model was evaluated via Monte Carlo simulation for the goodness-of-fit. Analysis of nonlinear goodness-of-fit showed that the Brix model is appropriate in evaluating the parotid perfusion (R2 = 0.938 ± 0.050). The irradiated parotid glands showed significantly lower Kel(P <0.0005) and k21 (P <0.05) and consequently significantly higher value of peak enhancement (P <0.0005) and time-to-peak (P <0.0005) compared with non-irradiated ones, suggestive of gradual and prolonged accumulation and delayed wash-out of contrast agent due to increased extracellular extravascular space and decreased vascular permeability in the irradiated glands. Linear regression analysis showed dose-dependent perfusion changes of the irradiated parotid glands. We conclude that quantitative DCE-MRI is a potential tool in investigating parotid gland perfusion changes after radiotherapy.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
Juan, C. J., Chen, C. Y., Jen, Y. M., Liu, H. S., Liu, Y. J., Hsueh, C. J., Wang, C. Y., Chou, Y. C., Chai, Y. T., Huang, G. S., & Chung, H. W. (2009). Perfusion characteristics of late radiation injury of parotid glands: Quantitative evaluation with dynamic contrast-enhanced MRI. European Radiology, 19(1), 94-102. https://doi.org/10.1007/s00330-008-1104-9