title: Tractographic reconstruction protocol optimization in the rat brain in-vivo: towards a normal atlas.
abstract: The tractographic reconstruction of anatomical and microstructural features provided by Magnetic Resonance (MR) Diffusion Tensor Imaging (DTI) gives essential information of brain damage in several pathological animal models. The optimization of a tractographic protocol is undertaken in normal rats for the future construction of a reference atlas, as prerequisite for preclinical pathological in-vivo studies. High field, preclinical in-vivo DTI faces important difficulties relevant to Signal-to-Noise Ratio (SNR), distortion, high required resolution, movement sensitivity. Given a pixel-size of 0.17 mm and TE/TR = 29/6500 ms, b value and slice thickness were fixed at 700 s/mm(2) and 0.58 mm, respectively, on preventive ex-vivo studies. In-vivo studies led to the choice of 30 diffusion directions, averaged on 16 runs. The final protocol required 51 min scanning and permitted a reliable reconstruction of main rat brain bundles. Tract reconstruction stopping rules required proper setting. In conclusion, the viability of DTI tractography on in-vivo rat studies was shown, towards the construction of a normal reference atlas.
authors.affiliation: IRCCS S Maria Nascente, Fondazione Don Carlo Gnocchi ONLUS, Milano, Italy.
authors.forename: Maria Giulia
authors.initials: MG
authors.lastname: Preti
authors.forename: Alessandro
authors.initials: A
authors.lastname: Di Marzio
authors.forename: Alfonso
authors.initials: A
authors.lastname: Mastropietro
authors.forename: Domenico
authors.initials: D
authors.lastname: Aquino
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Baselli
authors.forename: Maria Marcella
authors.initials: MM
authors.lastname: Laganà
authors.forename: Ileana
authors.initials: I
authors.lastname: Zucca
authors.forename: Carolina
authors.initials: C
authors.lastname: Frassoni
authors.forename: Roberto
authors.initials: R
authors.lastname: Spreafico
mesh_terms: D000716:Anatomy, Artistic; D000818:Animals; D001271:Atlases as Topic; D001921:Brain / Q000033:anatomy & histology*; D003337:Corpus Callosum / Q000033:anatomy & histology; D056324:Diffusion Tensor Imaging / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D059629:Signal-To-Noise Ratio