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Radial diffusion-weighted MRI enables motion-robustness and reproducibility for orthotopic pancreatic cancer in mouse

Jianbo Cao¹, Stephen Pickup¹, Hanwen Yang¹, Victor Castillo¹, Cynthia Clendenin^2,3, Peter O’Dwyer^2,3, Mark Rosen^1,3, and Rong Zhou^1,3
¹Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Pancreatic Cancer Research Center, University of Pennsylvania, Philadelphia, PA, United States, ³Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA, United States

Both Radial- and EPI-DW can effectively remove motion artefacts although ghosting persists in EPI-DW images. EPI-DW underestimates water ADC value at 37°C but radial-DW does not. Better test-retest producibility measured by within-subject CV is obtained only with radial-DW.

Figure 1 Comparison of Radial- vs. EPI-DW for motion suppression and ghosting.

DW-MR images obtained from respiration-gated SE- (A), Radial- (B) and EPI-DW (C) protocol using indicated b-values. White arrows in A point to motion artifacts at b=500 and above and to ghosting artefacts in EPI-DW images (C). Red frame and arrows in D indicate that of the five T2W images, slide-3 corresponds to DW-images displayed in B and C with different b-values. DW-images in A are from a different mouse.

Figure 3 Correlation and test-retest ADC values in tumor and muscle in comparison of radial vs. EPI DW-MRI Protocol

The tumor ADC values measured from Radial- and EPI-DW are highly correlated (A) (r²=0.82). Bland-Altman plots of tumor and muscle ADC value between test and retest data were shown for Radial-DW (B) and EPI-DW (C) protocol. More details in Table 1.