title: MRI signal loss due to microcirculation: phantom studies.
abstract: In order to study perfusion effects in MRI under different conditions we developed two different kinds of phantoms. The first phantom exhibits linear capillary flow with several capillaries within one voxel. The second consists of an anion exchange resin with beads forcing the spins to change directions such that they undergo accelerations and decelerations. Both phantoms were imaged with standard spin-echo sequences and signal intensities were quantified at various echo times. Qualitative and quantitative agreements of the data with the results obtained by computations of signal loss due to spin-phase phenomena are excellent, thus suggesting that perfusion effects can be fully understood using these phenomena. It is argued that the phantoms used in conjunction with conventional spin-echo sequences represent a realistic model for studying true capillary networks in conjunction with specialized perfusion sequences.
authors.affiliation: Department of Medical Radiology, University Hospital, Zurich, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Duewell
authors.forename: R
authors.initials: R
authors.lastname: Wüthrich
authors.forename: A
authors.initials: A
authors.lastname: Buck
authors.forename: C
authors.initials: C
authors.lastname: von Weymarn
authors.forename: G K
authors.initials: GK
authors.lastname: von Schulthess
mesh_terms: D006801:Humans; D008279:Magnetic Resonance Imaging; D008833:Microcirculation; D008955:Models, Cardiovascular; D008961:Models, Structural; D010477:Perfusion