Table 1.

The approaches reviewed here are summarized in the following table. We indicate the general approach, the form of anatomical information used and whether the method requires segmentation or labeling of the anatomical image prior to use in the reconstruction algorithm.

General Category	Method	Information Used	Anatomical image segmentation	References
Post processing	Two/three compartment	Region	Yes	(34, 35)
	GTM	Region	Yes	(36)
	PML	Region	Yes	(67)
Anatomical prior	Weighted Markov prior	Boundary	Yes	(45, 48)
	Line process	Boundary	Yes	(54-56, 58, 59, 68, 69)
	ALSM	Boundary	Yes	(57)
	Region based prior	Region	Yes	(44, 49-51, 53, 70, 71)
	Bowsher prior	Region	No	(46)
	Cross Entropy	Image intensity	No	(61)
	Mutual information	Image features	No	(62, 64, 65)
	Joint Entropy	Image features	No	(62-64, 66)