MR imaging of microvasculature

• Published in: Magnetic resonance in medicine Vol. 44; no. 2; pp. 224 - 230
• Main Authors: Jensen, J.H., Chandra, R.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 01-08-2000; Williams & Wilkins
• Subjects: angiogenesis; Animals; Biological and medical sciences; Brain Neoplasms - blood supply; Cardiovascular system; contrast agent; Contrast Media - administration & dosage; Ferrosoferric Oxide; Glioma - blood supply; Investigative techniques, diagnostic techniques (general aspects); Iron - administration & dosage; Magnetic Resonance Imaging; Medical sciences; Microcirculation; Models, Theoretical; MR imaging; Neovascularization, Pathologic - diagnosis; Neurology; Oxides - administration & dosage; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Rats; susceptibility contrast; tumor; Tumors of the nervous system. Phacomatoses; Animal model; Nervous system diseases; Correlation; Rat; Rodentia; Paramagnetic contrast agent; Case control study; Experimental study; Nuclear magnetic resonance imaging; Relaxation time; Angiogenesis; Vertebrata; Mammalia; Glioma; Animal; Central nervous system disease; Morphological analysis; Tumor; Blood capillary; Contrast threshold; Technique
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/1522-2594(200008)44:2<224::AID-MRM9>3.0.CO;2-M

An imaging technique is proposed in which the contrast is correlated to the morphology of capillaries and other small blood vessels. The technique is based on measurements of the relaxation rates 1/T2 and 1/T*2 before and after the injection of a contrast agent. An image is then formed by mapping the quantity Q ≡ ΔR2/(ΔR*2)2/3, where ΔR2 and ΔR*2 are the changes in the relaxation rates due to the contrast agent. If the contrast agent concentration is sufficiently high, it is shown that Q is given approximately by a simple analytic formula that involves only intrinsic properties of the vascular network and the rate of diffusion. In particular, Q is sensitive to the histologic vessel density. Theoretical predictions for Q are shown to be consistent with experimental data obtained with a rat glioma model and normal cerebral cortex. The imaging technique may be useful in characterizing tumor angiogenesis. Magn Reson Med 44:224–230, 2000. © 2000 Wiley‐Liss, Inc.