Chronic and treatment-resistant depression: a study using arterial spin labeling perfusion MRI at 3Tesla.

The aim of the present study was to compare patients displaying chronic and treatment-resistant depression with healthy controls, using the resting-state perfusion with arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) technique at 3T. The study focused on the subgenual anterior cingulate cortex (sACC), which is a key component in the pathophysiology of depression. Six patients with chronic and treatment-resistant depression and six healthy control subjects were included. ASL is an innovative imaging technique which sidesteps the limitations of other functional neuroimaging techniques (functional MRI, positron emission tomography). A statistical analysis of perfusion maps was performed using SPM2 software. Statistically significant hyperperfusion regions were found in the depressed patient group compared with the healthy control group in the following: the bilateral sACC, left prefrontal dorsomedian cortex, left ACC and left subcortical areas (putamen, pallidum and amygdala). This study confirmed the involvement of the sACC in depression, particularly chronic and treatment-resistant depression, using ASL at 3T, a safe perfusion technique that seems to be appropriate for investigating functional abnormalities in psychiatric disorders.