The Effect of Susceptibility of Gadolinium Contrast Media on Diffusion-weighted Imaging and the Apparent Diffusion Coefficient

The development of parallel magnetic resonance imaging has resulted in the frequent use of diffusion-weighted imaging (DWI) in clinical medicine, which usually involves the use of contrast medium. However, gadolinium (Gd) contrast medium may have some effect on DWI and the apparent diffusion coefficient (ADC). The present study was performed to determine whether the magnetic susceptibility of contrast medium alters the DWI signal and the value of ADC in some imaging techniques.Nonfat suppression DWI, short-time inversion recovery (STIR) combination, and chemical shift selective (CHESS) combination DWI were performed to examine 10 phantoms with gadolinium-meglumine gadopentetate (Gd-DTPA) dissolved at concentrations from 0.0005 to 0.1 mmol in physiologic saline as a contrast medium. The average pixel value and ADC of each method were determined.ADC showed no differences between before and after treatment with contrast medium for all imaging techniques with Gd considered distributed over the whole tumor. The signal intensity did not change on nonfat suppression or CHESS combination DWI, but deteriorated on STIR.ADC was not influenced by the magnetic susceptibility of contrast medium. In addition, it was suggested that the ability of tumor detection may be reduced if STIR is used as fat suppression.