TABLE II.

Notations used in this paper.

Symbol	Definition
N	Number of histology slices
$\mathcal{H}$	3D histology volume
${\mathcal{H}}_i$	Histology slice, i ∈ {1, …, N}
${\mathcal{H}}_i^m$	Unit m in ${\mathcal{H}}_i$
$\mathcal{A}$	Airways
$\tilde{\mathcal{M}}$	Ex vivo MRI
${\tilde{\mathcal{M}}}_i$	Ex vivo MRI slice, i ∈ {1, …, N}
$\mathcal{M}$	In vivo MRI
ψ	Optimized scoring function
${\psi }_{\mathcal{H}}$	Histology scoring function
${\psi }_{\mathcal{M}}$	Ex vivo MRI scoring function
MI	Mutual information
$\mathcal{T}$	Rigid transformation
wj	Weight of the adjacent slice
$\tilde{w}$	Weight of ex vivo term