title: Measurement of liver blood volume using a macromolecular MRI contrast agent at equilibrium.
abstract: Liver regional blood volume (LRBV) is altered by several disease states and various drugs. Preliminary studies in the rat, using research MR imaging instruments at 2T and vascular contrast agents, have suggested that MRI may be used to measure LRBV. Our goal was to develop a technique for measuring LRBV using a clinical machine at 1.5 T. This study was performed in the rabbit, using CarboxyMethylDextran Gd-DTPA, a macromolecular contrast agent with a molecular weight of 158 kDa. MRI was performed at 1.5 T, in the plane of the inferior vena cava, with and without flow compensation, before contrast injection and in the steady state after injection. Accuracy and stability of LRBV measurement, over 2 h and with various doses (0.01-0.05 mmol/kg), was tested against a standard Evan's Blue dye-indicator technique. LRBV was 28 +/- 2 mL/100 g when measured by MRI with flow compensation, which is in good agreement with the literature and with the 26 +/- 6 mL/100 g, measured by the Evan's Blue dilution technique. Measurements varied less than 7% over time and less than 9% over the range of doses. LRBV was overestimated using a sequence without flow compensation especially when large doses of contrast agent were injected. This noninvasive MRI technique provides a simple method for measuring liver LRBV and offers new prospects for future physiological and pathological studies.
authors.affiliation: Laboratoire de Recherche en Imagerie, Faculté Necker-Enfants Malades, Paris, France.
authors.forename: J
authors.initials: J
authors.lastname: Blustajn
authors.forename: C A
authors.initials: CA
authors.lastname: Cuenod
authors.forename: O
authors.initials: O
authors.lastname: Clement
authors.forename: N
authors.initials: N
authors.lastname: Siauve
authors.forename: V
authors.initials: V
authors.lastname: Vuillemin-Bodaghi
authors.forename: G
authors.initials: G
authors.lastname: Frija
mesh_terms: D000818:Animals; D004396:Coloring Agents; D003287:Contrast Media; D004395:Dye Dilution Technique; D005070:Evans Blue; D005682:Gadolinium; D019786:Gadolinium DTPA; D008099:Liver / Q000033:anatomy & histology / Q000098:blood supply*; D008102:Liver Circulation; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives*; D011817:Rabbits; D015203:Reproducibility of Results
chemical_list: D004396:Coloring Agents; D003287:Contrast Media; D009942:Organometallic Compounds; C089671:carboxylmethyl dextran gadopentetate dimeglumine; D005070:Evans Blue; D004369:Pentetic Acid; D005682:Gadolinium; D019786:Gadolinium DTPA