title: Assessment of murine brain tissue shrinkage caused by different histological fixatives using magnetic resonance and computed tomography imaging.
abstract: Especially for neuroscience and the development of new biomarkers, a direct correlation between in vivo imaging and histology is essential. However, this comparison is hampered by deformation and shrinkage of tissue samples caused by fixation, dehydration and paraffin embedding. We used magnetic resonance (MR) imaging and computed tomography (CT) imaging to analyze the degree of shrinkage on murine brains for various fixatives. After in vivo imaging using 7 T MRI, animals were sacrificed and the brains were dissected and immediately placed in different fixatives, respectively: zinc-based fixative, neutral buffered formalin (NBF), paraformaldehyde (PFA), Bouin-Holland fixative and paraformaldehyde-lysine-periodate (PLP). The degree of shrinkage based on mouse brain volumes, radiodensity in Hounsfield units (HU), as well as non-linear deformations were obtained. The highest degree of shrinkage was observed for PLP (68.1%, P < 0.001), followed by PFA (60.2%, P<0.001) and NBF (58.6%, P<0.001). The zinc-based fixative revealed a low shrinkage with only 33.5% (P<0.001). Compared to NBF, the zinc-based fixative shows a slightly higher degree of deformations, but is still more homogenous than PFA. Tissue shrinkage can be monitored non-invasively with CT and MR. Zinc-based fixative causes the smallest degree of brain shrinkage and only small deformations and is therefore recommended for in vivo ex vivo comparison studies.
authors.affiliation: Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Tuebingen, Germany.
authors.forename: Hans F
authors.initials: HF
authors.lastname: Wehrl
authors.affiliation: Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, and Department of Empirical Inference, Max-Planck-Institute for Intelligent Systems, Tuebingen, Germany.
authors.forename: Ilja
authors.initials: I
authors.lastname: Bezrukov
authors.affiliation: Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Tuebingen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Wiehr
authors.affiliation: Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Tuebingen, Germany.
authors.forename: Mareike
authors.initials: M
authors.lastname: Lehnhoff
authors.affiliation: Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Tuebingen, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Fuchs
authors.affiliation: Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Tuebingen, Germany.
authors.forename: Julia G
authors.initials: JG
authors.lastname: Mannheim
authors.affiliation: Department of Pathology, Eberhard Karls University Tuebingen, Tuebingen, Germany.
authors.forename: Leticia
authors.initials: L
authors.lastname: Quintanilla-Martinez
authors.affiliation: Department of Pathology, Eberhard Karls University Tuebingen, Tuebingen, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Kohlhofer
authors.affiliation: Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, and Department of Dermatology, Eberhard Karls University Tuebingen, Tuebingen, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Kneilling
authors.affiliation: Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Tuebingen, Germany.
authors.forename: Bernd J
authors.initials: BJ
authors.lastname: Pichler
authors.affiliation: Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, and Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, Tuebingen, Germany. alexander.sauter.imaging@gmail.com.
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Sauter
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000187:drug effects*; D005404:Fixatives / Q000737:chemistry*; D005557:Formaldehyde / Q000737:chemistry; D008239:Lysine / Q000737:chemistry; D008279:Magnetic Resonance Imaging; D051379:Mice; D008807:Mice, Inbred BALB C; D016612:Paraffin Embedding; D010504:Periodic Acid / Q000737:chemistry; D010851:Picrates / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D013997:Time Factors; D016707:Tissue Fixation; D014057:Tomography, X-Ray Computed; D015032:Zinc / Q000737:chemistry
chemical_list: D005404:Fixatives; D010851:Picrates; D011108:Polymers; C046311:periodate-lysine-paraformaldehyde; D010504:Periodic Acid; D005557:Formaldehyde; C026239:Bouin's solution; D015032:Zinc; D008239:Lysine; D019342:Acetic Acid; C003043:paraform