TABLE 1.

Comparison of Magnetic Resonance Imaging (MRI) Methods for Assessing Structural Deficits in Geriatric Depression

Method	Strengths	Weaknesses	State of Development
MRI volumetry	Simple to implement	Time-consuming; laboratory-dependent	Commonly used
Voxelwise analyses	Highly automated	Depends highly on image registration quality	Relatively new
White matter hyperintensities	Simple to implement	Typically rated subjectively	Commonly used
DTI	Highly sensitive to pathology	Not specific as to pathology	Development of optimized sequences and analytic methods
MTR	Specific to macromolecules	Relatively low signal-to-noise ratio; not quantitative	Few studies
T2R	Specific to myelin	Time-consuming; does not yield whole brain information	Not applied to geriatric depression yet
MR spectroscopy	Chemically specific	Poor spatial and temporal resolution	Needs better multislice implementation