title: A non-invasive method of quantifying pancreatic volume in mice using micro-MRI.
abstract: In experimental models of pancreatic growth and recovery, changes in pancreatic size are assessed by euthanizing a large cohort of animals at varying time points and measuring organ mass. However, to ascertain this information in clinical practice, patients with pancreatic disorders routinely undergo non-invasive cross-sectional imaging of the pancreas using magnetic resonance imaging (MRI) or computed tomography (CT). The aim of the current study was to develop a thin-sliced, optimized sequence protocol using a high field MRI to accurately calculate pancreatic volumes in the most common experimental animal, the mouse. Using a 7 Telsa Bruker micro-MRI system, we performed abdominal imaging in whole-fixed mice in three standard planes: axial, sagittal, and coronal. The contour of the pancreas was traced using Vitrea software and then transformed into a 3-dimensional (3D) reconstruction, from which volumetric measurements were calculated. Images were optimized using heart perfusion-fixation, T1 sequence analysis, and 0.2 to 0.4 mm thick slices. As proof of principle, increases in pancreatic volume among mice of different ages correlated tightly with increasing body weight. In summary, this is the first study to measure pancreatic volumes in mice, using a high field 7 Tesla micro-MRI and a thin-sliced, optimized sequence protocol. We anticipate that micro-MRI will improve the ability to non-invasively quantify changes in pancreatic size and will dramatically reduce the number of animals required to serially assess pancreatic growth and recovery.
authors.affiliation: Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC and the University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Paredes
authors.affiliation: Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC and the University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Abrahim I
authors.initials: AI
authors.lastname: Orabi
authors.affiliation: Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC and the University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Taimur
authors.initials: T
authors.lastname: Ahmad
authors.affiliation: Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC and the University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Iman
authors.initials: I
authors.lastname: Benbourenane
authors.affiliation: Department of Developmental Biology, Children's Hospital of Pittsburgh of UPMC and the University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Kimimasa
authors.initials: K
authors.lastname: Tobita
authors.affiliation: Department of Radiology, Children's Hospital of Pittsburgh of UPMC and the University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Sameh
authors.initials: S
authors.lastname: Tadros
authors.affiliation: Department of Radiology, Children's Hospital of Pittsburgh of UPMC and the University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Kyongtae T
authors.initials: KT
authors.lastname: Bae
authors.affiliation: Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC and the University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Sohail Z
authors.initials: SZ
authors.lastname: Husain
mesh_terms: D000375:Aging; D000818:Animals; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D051379:Mice; D009929:Organ Size; D010179:Pancreas / Q000033:anatomy & histology / Q000254:growth & development*; D019047:Phantoms, Imaging