MRI Assessment of Amygdalar Size Based on a Single Plane Measurement in Patients with Clinical Diagnosis of Alzheimer's Disease and Mild Cognitive Impairment

Abstract

MRI volumetry of the amygdala is a relevant marker of the severity of dementia in Alzheimer's disease. To evaluate the changes of amygdalar volume, there are many manual tracing techniques, which are time‐consuming for clinicians. On the basis of our previous studies, we developed an easy method which allows estimation of the total volume of the amygdala from a simple referential section (frontal section in the level of the anterior pole of the hippocampus). Boundaries of the amygdala in this level are clear and can be easily distinguished from neighboring structures. This protocol was developed with a sample of 70 healthy brains (anatomical preparations and MRI's of healthy volunteers). The average area of the sections through the amygdala in the reference level was 1.64 cm2 (SD=0.23). In normal brains, the referential section correlated highly with the total volume (r=0.65). A sample of 20 patients with the clinical diagnosis of Alzheimer's disease showed the correlation even higher (r=0.82). In patients with the Mild Cognitive Impairment (n=16), the correlation was 0.87. Using our protocol, clinicians can be informed about amygdalar size within a few minutes without the requirements of lengthy measurement.Supported by grants IGA MZ 2006 NR8931‐4, and No. 0021620806 from the Ministry of Education of the Czech RepublicGrant Funding SourceIGA MZ CR NR8931‐4 ,