title: Immobilized contrast-enhanced MRI: Gadolinium-based long-term MR contrast enhancement of the vein graft vessel wall.
abstract: An implantable MR contrast agent that can be covalently immobilized on tissue during surgery has been developed. The rationale is that a durable increase in tissue contrast using an implantable contrast agent can enhance postsurgical tissue differentiation using MRI. For small-vessel (e.g., vein graft) MRI, the direct benefit of such permanent "labeling" of the vessel wall by modification of its relaxation properties is to achieve more efficient imaging. This efficiency can be realized as either increased contrast leading to more accurate delineation of vessel wall and lesion tissue boundaries, or, faster imaging without penalizing contrast-to-noise ratio, or a combination thereof. We demonstrate, for the first time, stable long-term MRI enhancement using such an exogenous contrast mechanism based on immobilizing a modified diethylenetriaminepentaacetic acid gadolinium(3+) dihydrogen complex on a human vein using a covalent amide bond. Signal enhancement due to the covalently immobilized contrast agent is demonstrated for excised human vein specimens imaged at 3 T, and its long-term stability is demonstrated during a 4-month incubation period.
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA. dmitsouras@alum.mit.edu
authors.forename: Dimitris
authors.initials: D
authors.lastname: Mitsouras
authors.forename: Praveen Kumar
authors.initials: PK
authors.lastname: Vemula
authors.forename: Peng
authors.initials: P
authors.lastname: Yu
authors.forename: Ming
authors.initials: M
authors.lastname: Tao
authors.forename: Binh T
authors.initials: BT
authors.lastname: Nguyen
authors.forename: Christina M
authors.initials: CM
authors.lastname: Campagna
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Karp
authors.forename: Robert V
authors.initials: RV
authors.lastname: Mulkern
authors.forename: C Keith
authors.initials: CK
authors.lastname: Ozaki
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Rybicki
mesh_terms: D003287:Contrast Media / Q000138:chemical synthesis; D003692:Delayed-Action Preparations / Q000138:chemical synthesis*; D019786:Gadolinium DTPA / Q000737:chemistry*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D066298:In Vitro Techniques; D018810:Magnetic Resonance Angiography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D058017:Vascular Grafting; D014680:Veins / Q000033:anatomy & histology* / Q000737:chemistry / Q000637:transplantation
chemical_list: D003287:Contrast Media; D003692:Delayed-Action Preparations; D019786:Gadolinium DTPA