Hye-Jeong Lee MD, Presenter: Nothing to Disclose

Jin Hur MD, Abstract Co-Author: Nothing to Disclose

Young Jin Kim MD, Abstract Co-Author: Nothing to Disclose

Ji Eun Nam MD, Abstract Co-Author: Nothing to Disclose

Yoo Jin Hong, Abstract Co-Author: Nothing to Disclose

Hee-Yeong Kim, Abstract Co-Author: Nothing to Disclose

Ji Won Lee MD, Abstract Co-Author: Nothing to Disclose

Byoung Wook Choi MD, Abstract Co-Author: Nothing to Disclose

Kyu Ok Choe MD, Abstract Co-Author: Nothing to Disclose

To compare the apparent diffusion coefficient (ADC) of diffusion-weighted MR imaging (DWI) with histological vascular density in a mouse tumor model for the possibility of future noninvasive evaluations of microvessel density (MVD) with DWI.

The study protocol was approved by the animal care and use committee of our institution. Sixteen nude-mice which had undergone single injections of the HT29 colorectal cancer cells in one flank underwent DWI and T2-weighted spin echo (T2-SE) in a 3.0-T unit. DWI was obtained with various b gradient values (b value = 0, 50, 100, 300, 500, 700, and 1000 sec/mm2). The whole tumor analysis was used and the region of interest (ROI) was drawn around each entire tumor on the DWI. Calculations for ADCs between a b value of 0 and other b values for each tumor were based on the signal intensity of the DWI. ROIs were drawn manually around the tumor on the T2-SE by qualitative assessment covering the entire tumor and tumor volume was generated by summation. Histopathologic examinations were performed immediately after each MRI. The MVD score was determined for each tumor with the factor VIII stain. For statistical analyses, a Spearman’s rho correlation was applied.

The mean values of tumor volume and MVD scores were 328.24 ± 176.84mm3 and 56.25 ± 12.14, and there was no significant correlation between the two values (correlation coefficient 0.394, p=0.131). The mean values of the ADC (x 10-3 mm2/s) were as follows: ADC0-50, 2.85 ± 0.55; ADC0-100, 2.07 ± 0.50; ADC0-300, 0.99 ± 0.21; ADC0-500, 0.77 ± 0.17; ADC0-700, 0.73 ± 0.31; ADC0-1000, 0.64 ± 0.23. There was significant correlation between the MVD scores and the ADC0-50 (correlation coefficient 0.971, p=0.000), and also with the ADC0-100 (correlation coefficient 0.753, p=0.001). However there were no significant correlations between the MVD scores and the ADC0-300 (correlation coefficient 0.335, p=0.204), the ADC0-500 (correlation coefficient 0.403, p=0.122), the ADC0-700 (correlation coefficient 0.300, p=0.184), and the ADC0-1000 (correlation coefficient 0.302, p=0.256).

The ADCs a b value of 0 and low b values (50 and 100) were significantly correlated with the MVD scores. DWI can provide additional information about MVD to information about cellularity in tumors.

DWI parameters may help predict MVD and may be used to predict prognosis and therapeutic outcomes.

Lee, H, Hur, J, Kim, Y, Nam, J, Hong, Y, Kim, H, Lee, J, Choi, B, Choe, K, The Tumor Perfusion-related Parameter of Diffusion-weighted Magnetic Resonance Imaging: Correlation with Microvessel Density.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11007564.html