Tissue pH measurement by magnetic resonance spectroscopy and imaging.
Noninvasive techniques for measurement of tissue pH can be invaluable in assessing disease extent and response to therapy in a variety of pathological conditions, such as renal acidosis and alkalosis, and cancers. We present the details of three techniques for noninvasive measurement of tissue pH: magnetic resonance spectroscopy (MRS), magnetic resonance spectroscopic imaging (MRSI), and contrast-enhanced magnetic resonance imaging (MRI). These techniques exploit the pH-sensitivity of three different molecules, 3-aminopropylphosphonate (3-APP), (+/-) 2-imidazole-1-yl-3-ethoxycarbonyl propionic acid (IEPA), and 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetrakis(acetamidomethylenephosphonic acid) (Gd-DOTA-4AmP), to examine local extracellular pH in vivo. The level of detail presented will enable nonnovice users of MRS and MRI to reproduce these methodologies in their own laboratories.
Raghunand
Natarajan
N
Arizona Cancer Center, University of Arizona, Tucson, USA.
D000818:Animals; D003238:Connective Tissue / Q000737:chemistry*; D003287:Contrast Media; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*
D003287:Contrast Media