Altered structural brain networks at term-equivalent age in preterm infants with grade 1 intraventricular hemorrhage

Table 1 Definitions and descriptions of network metrics

Network metrics	Definitions	Descriptions
Measures of segregation
Clustering coefficient (Cp)	$ {L}_p=\frac{1}{N\left(N-1\right)}\sum \limits_{i\in G}\sum \limits_{j\in G,j\ne i}{L}_{ij} $	L_ij is the shortest path length between nodes i and j, N is the set of all nodes in the network G.
Local efficiency (Eloc)	$ {E}_{local}=\frac{1}{N}\sum \limits_{i\in G}{E}_{local,i} $	E_{local, i} is the local efficiency of node i.
Measures of integration
Characteristic path length (Lp)	$ {C}_p=\frac{1}{N}\sum \limits_{i\in G}\frac{2\ast {E}_i}{k_i\left({k}_i-1\right)} $	k_i is the degree of node i, E_i is the number of edges that consists of the neighbors of node i.
Global efficiency (Eglob)	$ {E}_{glob}=\frac{1}{N\left(N-1\right)}\sum \limits_{i\in G}\sum \limits_{j\in G,j\ne i}\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{${L}_{ij}$}\right. $	It is inversely related to L_p.
Other concepts
Small-worldness (σ)	$ \upsigma =\frac{L_p/{L}_{ran}}{C_p/{C}_{ran}} $	σ measures small-worldness. Cran and Lran were averaged from 100 matched random networks.

Cran, clustering coefficient for a random network; Lran, characteristic for a random network

ISSN: 1824-7288

Network metrics	Definitions	Descriptions
Measures of segregation
Clustering coefficient (Cp)	\( {L}_p=\frac{1}{N\left(N-1\right)}\sum \limits_{i\in G}\sum \limits_{j\in G,j\ne i}{L}_{ij} \)	L_ij is the shortest path length between nodes i and j, N is the set of all nodes in the network G.
Local efficiency (Eloc)	\( {E}_{local}=\frac{1}{N}\sum \limits_{i\in G}{E}_{local,i} \)	E_{local, i} is the local efficiency of node i.
Measures of integration
Characteristic path length (Lp)	\( {C}_p=\frac{1}{N}\sum \limits_{i\in G}\frac{2\ast {E}_i}{k_i\left({k}_i-1\right)} \)	k_i is the degree of node i, E_i is the number of edges that consists of the neighbors of node i.
Global efficiency (Eglob)	\( {E}_{glob}=\frac{1}{N\left(N-1\right)}\sum \limits_{i\in G}\sum \limits_{j\in G,j\ne i}\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{${L}_{ij}$}\right. \)	It is inversely related to L_p.
Other concepts
Small-worldness (σ)	\( \upsigma =\frac{L_p/{L}_{ran}}{C_p/{C}_{ran}} \)	σ measures small-worldness. Cran and Lran were averaged from 100 matched random networks.