Effect of Intravenous Gadolinium-DTPA on Diffusion-Weighted Images

Abstract

Background and Purpose-Diffusion-weighted imaging (DWI) is usually done before administration of intravenous contrast agents. Repetition of DWI is occasionally necessary after administration, but the effects of contrast material on DWI and apparent diffusion coefficient (ADC) values have not yet been fully examined. The present study assesses whether administration of gadolinium-based contrast material significantly affects DWI and ADC values. Methods-We examined DWI data from 39 patients (mean age, 67.9 years; range, 34 to 87 years) who were evaluated with a stroke protocol at our institute. All patients were scanned at the acute or subacute stages of infarct from 3 hours to 5 days after symptom onset. We obtained DWI images using single-shot echo-planar imaging with a b value of 1000 s/mm 2 . Patients were injected with 0.1 mmol gadopentetate dimeglumine per 1 kg body weight. We examined the signal-to-noise ratio of the normal brain and the infarct and evaluated the contrast-to-noise ratio of each lesion. In addition, we compared the ADC values calculated from the DWI images before and after administration of contrast. The statistical significance of differences between precontrast and postcontrast administration was determined by use of a paired t test. Results-The signal-to-noise and contrast-to-noise ratios of the DW images were not significantly different before and after administration of contrast agent. The ADC values were slightly lower after administration of contrast agent for both normal brain (Pϭ0.0011) and infarcts (Pϭ0.038). The estimated differences in the ADC values were Ϸ1.3% and 3.5% for normal brain and infarcts, respectively. Conclusions-The lack of a significant difference between the signal-to-noise and contrast-to-noise ratios of DW images before and after administration of contrast agent indicates the feasibility of postcontrast DWI.

Sensitivity and specificity of unenhanced MR mammography (DWI combined with T2-weighted TSE imaging, ueMRM) for the differentiation of mass lesions

“…Our own phantom experiments (see supplemental material 1) on Gd-DTPA solutions of 0.05 -7 mmol/l did not show a significant influence on the DWI technique used in the expected Gd-DTPA concentration. This finding is backed up by several experimental and clinical studies using a physically comparable EPI-DWI technique in Gd-enhancing lesions [29][30][31]. A recent investigation on breast DWI reported a contrast medium influence on ADC measurements.…”

Effects of Iodinated Contrast Agent on Diffusion Weighted Magnetic Resonance Imaging

“…Detection of a malignant tumour is based on the increase in signal intensity on DWI, and discrimination between benign and malignant tumours is based on the apparent diffusion coefficient (ADC). However, several factors may alter the ADC (7)(8)(9)(10)(11). Iodinated contrast agents are predicted to affect the ADC due to their high viscosity and large molecular size.…”

Diffusion-Weighted MR Imaging of Benign and Malignant Breast Lesions Before and After Contrast Enhancement

“…There are some studies dealing with the influence of CM on the ADC value of normal brain tissue and infarcts. Yamada et al found a significant decrease of the ADC value after CM administration [20], while there was no difference in the study of Fitzek et al [21]. In the study of Yamada et al, DWI was obtained immediately after CM application, while there was a longer time interval in the study of Fitzek et al Firat et al combined both protocols and found a significant decrease of the ADC value of normal brain tissue and infarct immediately after CM application which normalized in the late post-contrast DW images [22].…”