Vascular Tree Segmentation in Medical Images Using Hessian-Based Multiscale Filtering and Level Set Method

Table 1

Possible structure orientations in 3D images depending on the eigenvalues of Hessian matrix.

Orientation pattern	3D image
	𝜆1	𝜆2	𝜆3
Noisy, no preferred direction	L	L	L
Plate-like structure (bright)	L	L	H−
Plate-like structure (dark)	L	L	H+
Tubular structure (bright)	L	H−	H−
Tubular structure (dark)	L	H+	H+
Blob-like structure (bright)	H−	H−	H−
Blob-like structure (dark)	H+	H+	H+

L: Low, H+: high positive, H−: high negative.