Hersh Chandarana MD, Abstract Co-Author: Nothing to Disclose

Stella Kang MD, Presenter: Nothing to Disclose

Eric Sigmund, Abstract Co-Author: Nothing to Disclose

Jeff L. Zhang PhD, Abstract Co-Author: Nothing to Disclose

William C Huang MD, Abstract Co-Author: Nothing to Disclose

Michael Stifelman MD, Abstract Co-Author: Nothing to Disclose

Vivian Shu-Ching Lee MD, PhD, Abstract Co-Author: Nothing to Disclose

To determine relationship between perfusion and cellularity metrics obtained with intravoxel incoherent motion (IVIM) model of diffusion and those obtained with dynamic contrast enhanced (DCE) perfusion imaging

In this HIPAA compliant prospective study, 10 patients (4M 6F; mean age 54Y) with renal mass scheduled for surgery underwent preoperative MRI at 1.5 T and had diffusion (DWI) and DCE data available for analysis. Single shot echo planar DWI was performed in a transverse plane with 8 b values (0,50,100,150,250,400,600, and 800 s/mm2), and 2 averages. A biexponential model was employed to measure markers from a vascular compartment occupying a perfusion fraction Fp of the tumor volume in each voxel, and a cellular compartment showing a tissue diffusivity Dt . DCE data were acquired in the coronal plane after injection of 4 cc of Gd-DTPA (with 5 second scan delay) with k-space under sampling technique TWIST (TAfull = 5.2 sec and TAtwist = 1.2 sec with pA and pB = 0.2). 21 measures were acquired in a breath-hold followed by 3 measures every 30 second for 4 minutes. Renal lesions were segmented to generate signal intensity-time and concentration-time curves. Two-compartment adiabatic tissue homogeneity model was used to calculate tumor perfusion (F), vascular volume (Va), and extravascular extracellular volume (Ve). Vascular and cellular tissue parameters obtained by IVIM were correlated with DCE parameters.

IVIM: Fp (%) of the renal masses ranged from 10.6 to 27.8 with the average of 19.4. Dt (expressed in x 10-3 mm2/s) ranged from 0.48 to 2.42 with average of 1.54. One lesion was hemorrhagic, and had the lowest Dt of 0.48. DCE: F (ml/s/gm of tissue) of the renal mass range from 0.09 to 5.23 with the average of 2.33, Va range from 1.34 to 58.45 with the average of 19.3, and Ve range from 0.09 to 0.99 with average of 0.44. Correlations: There was moderate correlation between vascular parameters Fp and F (r=0.59) as well as Fp and Va (r=0.52). Cellularity parameters Dt and Ve demonstrated good correlation (r=0.77).  

There is moderate to good correlation observed between analogous IVIM and PWI parameters of vascularity and cellularity in renal cell cancers.

IVIM-DWI and DCE metrics of tumor vascularity and cellularity demonstrate moderate to good correlation and thus have potential to provide information about tumor aggressiveness or treatment response.

Chandarana, H, Kang, S, Sigmund, E, Zhang, J, Huang, W, Stifelman, M, Lee, V, Are the Angiogenesis and Cellularity Metrics Obtained with Diffusion and Perfusion MR Imaging in Renal Cell Carcinoma Correlated?.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9010661.html