title: Magnetic resonance imaging--cardiac ejection fraction measurements. Phantom study comparing four different methods.
abstract: The accuracy of cardiac ejection fraction (EF) measurements with thin, contiguous cine-magnetic resonance imaging (MR) sections is well established. Still, faster imaging and measurement techniques would be desirable. The authors evaluated the accuracy of four different MR EF measurements methods in a biventricular, anthropomorphic, foam-latex rubber phantom which was connected via noncompliant fluid-filled tubing to a pulsatile flow pump. Nine contiguous 10 mm cine-MR sections (TR/TE, 25/13; flip angle, 45 degrees) were obtained through the heart in long and short cardiac axes at 16 frames per cardiac cycle at a pump rate of 60 beats/minute. EF measurements were based on either the multi-slice summation technique (nine contiguous 10-mm sections versus four 10-mm sections spaced 10 mm apart) or the area-length method (single largest long section versus combination of largest long- and short-axis section). Three replications were performed for each of the tested EFs (40.8%, 29.4%, and 13.4%), which were compared with actual EFs. EF measurements based on contiguous 1-cm sections correlated best with the actual EFs. Average relative errors ranged from 3.2% to 6.0%. EF measurements based on every other section were less accurate; average relative errors were between 5.2% and 10.2%. Single and biplane area-length algorithm EF measurements were significantly less accurate; average relative errors were as high as 59%. EF measurements based on multi-slice summation are more accurate than those based on the area-length algorithm. Contiguous 1-cm section acquisitions are most accurate and most time consuming. With slight decrease of accuracy, acquisition and processing times can be halved by skipping every other slice.
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, NC 27710.
authors.forename: J F
authors.initials: JF
authors.lastname: Debatin
authors.forename: S N
authors.initials: SN
authors.lastname: Nadel
authors.forename: H D
authors.initials: HD
authors.lastname: Sostman
authors.forename: C E
authors.initials: CE
authors.lastname: Spritzer
authors.forename: A J
authors.initials: AJ
authors.lastname: Evans
authors.forename: T M
authors.initials: TM
authors.lastname: Grist
mesh_terms: D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008961:Models, Structural; D013318:Stroke Volume