title: Effect of intravenous gadolinium-DTPA on diffusion-weighted imaging of brain tumors: a short temporal interval assessment.
abstract: OBJECTIVE
  To determine the effect of intravenous administration of gadolinium (Gd) contrast medium (Gd-DTPA) on diffusion-weighted imaging (DWI) for the evaluation of normal brain parenchyma vs. brain tumor following a short temporal interval.
  
  
  METHODS
  Forty-four DWI studies using b values of 0 and 1000 s/mm(2) were performed before, immediately after, 1 min after, 3 min after, and 5 min after the administration of Gd-DTPA on 62 separate lesions including 15 meningioma, 17 glioma and 30 metastatic lesions. The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and apparent diffusion coefficient (ADC) values of the brain tumor lesions and normal brain tissues were measured on pre- and postcontrast images. Statistical analysis using paired t-test between precontrast and postcontrast data were obtained on three brain tumors and normal brain tissue.
  
  
  RESULTS
  The SNR and CNR of brain tumors and the SNR of normal brain tissue showed no statistical differences between pre- and postcontrast (P > 0.05). The ADC values on the three cases of brain tumors demonstrated significant initial increase on the immediate time point (P < 0.01) and decrease on following the 1 min time point (P < 0.01) after contrast. Significant decrease of ADC value was still found at 3min and 5min time point in the meningioma group (P < 0.01) with gradual normalization over time. The ADC values of normal brain tissues demonstrated significant initial elevation on the immediately postcontrast DWI sequence (P < 0.01).
  
  
  CONCLUSIONS
  Contrast medium can cause a slight but statistically significant change on the ADC value within a short temporal interval after the contrast administration. The effect is both time and lesion-type dependent.
authors.affiliation: Department of Radiology, the Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: Jin-Rong
authors.initials: JR
authors.lastname: Qu
authors.forename: Jun-Peng
authors.initials: JP
authors.lastname: Luo
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Hong-Kai
authors.initials: HK
authors.lastname: Zhang
authors.forename: Nan-Nan
authors.initials: NN
authors.lastname: Shao
authors.forename: Keith
authors.initials: K
authors.lastname: Kwok
authors.forename: Shou-Ning
authors.initials: SN
authors.lastname: Zhang
authors.forename: Yan-le
authors.initials: YL
authors.lastname: Li
authors.forename: Cui-Cui
authors.initials: CC
authors.lastname: Liu
authors.forename: Chi-Shing
authors.initials: CS
authors.lastname: Zee
authors.forename: Hai-Liang
authors.initials: HL
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000175:diagnosis*; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D059629:Signal-To-Noise Ratio
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: MRI; apparent diffusion coefficients; brain tumor; diffusion weighted imaging; gadolinium contrast