Dynamic Gd-DTPA enhanced MRI measurement of tissue cell volume fraction. Magn Reson Med 1995 Sep;34(3):423-32
Date
09/01/1995Pubmed ID
7500882DOI
10.1002/mrm.1910340320Scopus ID
2-s2.0-0029155698 (requires institutional sign-in at Scopus site) 91 CitationsAbstract
A new technique for measuring tissue cellular volume fraction, based on an improved modeling of the dynamic distribution of Gd-DTPA and the effect of proton exchange, is described. This technique uses peak T1 enhancement and blood Gd-DTPA concentration to compute tissue cellular volume fraction. The feasibility of this technique is demonstrated with computer simulations that explore the limits of the simplifying assumptions (small vascular space, slow vascular-extravascular proton exchange), and by direct comparison of MR and radionuclide cell fraction measurements made in muscle, liver, and tumor tissue in a rat model. The computer simulations demonstrate that with slow to intermediate vascular proton exchange and vascular fractions less than 10% the error in our cell fraction measurements typically remains less than 10%. Consistent with this prediction, a direct comparison between MR and radionuclide measurements of cell fraction demonstrates mean percent differences of less than 10%:1.9% in muscle (n = 4); 9% in liver (n = 1) and 9.5% in tumor (n = 4). Similarly, for all rats studied, the MR-measured cell fractions (muscle (0.92 +/- 0.04, n = 20); liver (0.76 +/- 0.11, n = 9); whole tumor (0.69 +/- 0.15, n = 22)) agree with the cell fraction values reported in the literature. In general, the authors' results demonstrate the feasibility of a simple method for measuring tissue cell fraction that is robust across a broad range of vascular volume, flow, and exchange conditions. Consequently, this method may prove to be an important means for evaluating the response of tumors to therapy.
Author List
Donahue KM, Weisskoff RM, Parmelee DJ, Callahan RJ, Wilkinson RA, Mandeville JB, Rosen BRAuthor
Kathleen M. Schmainda PhD Professor in the Biophysics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsCell Size
Computer Simulation
Contrast Media
Female
Gadolinium DTPA
Liver
Magnetic Resonance Imaging
Magnetic Resonance Spectroscopy
Mammary Neoplasms, Experimental
Muscle, Skeletal
Organometallic Compounds
Pentetic Acid
Rats
Rats, Inbred F344