title: MR imaging of pulmonary parenchyma and emboli by paramagnetic and superparamagnetic contrast agents.
abstract: Using experimentally induced pulmonary emboli in an animal model, three intravenously administered contrast agents, Gd-DTPA-albumin microspheres (8-15 microns, 0.2 M particles/mg protein, 39-106 micrograms Gd/mg, 50 mg/ml), Gd-DTPA-liposomes (15-30 microns, 130 micrograms/mg lipid, 6 mg Gd/ml) and superparamagnetic ferrosome, (60 nm, 100 mM iron and 20 mg lipid/ml) were examined for MR imaging. Gd-DTPA entrapped in lung capillaries did not enhance the signal intensity of lung parenchyma, but liposomes (5 ml) served as better Gd-DTPA carriers and increased the parenchymal signal intensity by up to a factor of 2.3. However, neither agent improved delineation of pulmonary emboli. Ferrosome decreased the intensity of lung parenchyma, improving detectability of pulmonary emboli by several factors.
authors.affiliation: Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
authors.forename: M L
authors.initials: ML
authors.lastname: Thakur
authors.forename: S
authors.initials: S
authors.lastname: Vinitski
authors.forename: D G
authors.initials: DG
authors.lastname: Mitchell
authors.forename: P M
authors.initials: PM
authors.lastname: Consigny
authors.forename: S
authors.initials: S
authors.lastname: Lin
authors.forename: J
authors.initials: J
authors.lastname: DeFulvio
authors.forename: M
authors.initials: M
authors.lastname: Rifkin
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D005290:Ferric Compounds; D005682:Gadolinium / Q000008:administration & dosage; D019786:Gadolinium DTPA; D007089:Image Enhancement; D008081:Liposomes / Q000008:administration & dosage; D008168:Lung / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008863:Microspheres; D009942:Organometallic Compounds / Q000008:administration & dosage; D004369:Pentetic Acid / Q000008:administration & dosage; D011655:Pulmonary Embolism / Q000175:diagnosis* / Q000473:pathology; D011817:Rabbits
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; D008081:Liposomes; D009942:Organometallic Compounds; C067317:ferrosome; D004369:Pentetic Acid; D005682:Gadolinium; D019786:Gadolinium DTPA