title: Geometrical models for cardiac MRI in rodents: comparison of quantification of left ventricular volumes and function by various geometrical models with a full-volume MRI data set in rodents.
abstract: MRI has been proven to be an accurate method for noninvasive assessment of cardiac function. One of the current limitations of cardiac MRI is that it is time consuming. Therefore, various geometrical models are used, which can reduce scan and postprocessing time. It is unclear how appropriate their use is in rodents. Left ventricular (LV) volumes and ejection fraction (EF) were quantified based on 7.0 Tesla cine-MRI in 12 wild-type (WT) mice, 12 adipose triglyceride lipase knockout (ATGL(-/-)) mice (model of impaired cardiac function), and 11 rats in which we induced cardiac ischemia. The LV volumes and function were either assessed with parallel short-axis slices covering the full volume of the left ventricle (FV, gold standard) or with various geometrical models [modified Simpson rule (SR), biplane ellipsoid (BP), hemisphere cylinder (HC), single-plane ellipsoid (SP), and modified Teichholz Formula (TF)]. Reproducibility of the different models was tested and results were correlated with the gold standard (FV). All models and the FV data set provided reproducible results for the LV volumes and EF, with interclass correlation coefficients ≥0.87. All models significantly over- or underestimated EF, except for SR. Good correlation was found for all volumes and EF for the SR model compared with the FV data set (R(2) ranged between 0.59-0.95 for all parameters). The HC model and BP model also predicted EF well (R(2) ≥ 0.85), although proved to be less useful for quantitative analysis. The SP and TF models correlated poorly with the FV data set (R(2) ≥ 0.45 for EF and R(2) ≥ 0.29 for EF, respectively). For the reduction in acquisition and postprocessing time, only the SR model proved to be a valuable method for calculating LV volumes, stroke volume, and EF.
authors.affiliation: Dept. of Radiology, Maastricht Univ. Medical Centre, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands.
authors.forename: Tineke
authors.initials: T
authors.lastname: van de Weijer
authors.forename: Petronella A
authors.initials: PA
authors.lastname: van Ewijk
authors.forename: H Reinier
authors.initials: HR
authors.lastname: Zandbergen
authors.forename: Jos M
authors.initials: JM
authors.lastname: Slenter
authors.forename: Alfons G
authors.initials: AG
authors.lastname: Kessels
authors.forename: Joachim E
authors.initials: JE
authors.lastname: Wildberger
authors.forename: Matthijs K C
authors.initials: MK
authors.lastname: Hesselink
authors.forename: Patrick
authors.initials: P
authors.lastname: Schrauwen
authors.forename: Vera B
authors.initials: VB
authors.lastname: Schrauwen-Hinderling
authors.forename: Marianne Eline
authors.initials: ME
authors.lastname: Kooi
mesh_terms: D000818:Animals; D057791:Cardiac Imaging Techniques / Q000379:methods* / Q000592:standards; D002306:Cardiac Volume / Q000502:physiology*; D004195:Disease Models, Animal; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009203:Myocardial Infarction / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D013318:Stroke Volume / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*