A practical guideline for intracranial volume estimation in patients with Alzheimer’s disease

Authors

Saman Sargolzaei, Department of Electrical and Computer Engineering, Florida International UniversityFollow
Arman Sargolzaei, Department of Electrical and Computer Engineering, Florida International UniversityFollow
Mercedes Cabrerizo, Department of Electrical and Computer Engineering, Florida International UniversityFollow
Gang Chen, Scientific and Statistical Computing Core, NIMH/NIH/HHS
Mohammed Goryawala, University of MiamiFollow
Shirin Noei, Department of Civil and Environmental Engineering, Florida International UniversityFollow
Qi Zhou, Department of Electrical and Computer Engineering, Florida International UniversityFollow
Ranjan Duara, Mount Sinai Medical Center
Warren Barker, Mount Sinai Medical Center
Malek Adjouadi, Department of Electrical and Computer Engineering, Florida International UniversityFollow

Date of this Version

12-2014

Document Type

Article

Abstract

Background

Intracranial volume (ICV) is an important normalization measure used in morphometric analyses to correct for head size in studies of Alzheimer Disease (AD). Inaccurate ICV estimation could introduce bias in the outcome. The current study provides a decision aid in defining protocols for ICV estimation in patients with Alzheimer disease in terms of sampling frequencies that can be optimally used on the volumetric MRI data, and the type of software most suitable for use in estimating the ICV measure.

Methods

Two groups of 22 subjects are considered, including adult controls (AC) and patients with Alzheimer Disease (AD). Reference measurements were calculated for each subject by manually tracing intracranial cavity by the means of visual inspection. The reliability of reference measurements were assured through intra- and inter- variation analyses. Three publicly well-known software packages (Freesurfer, FSL, and SPM) were examined in their ability to automatically estimate ICV across the groups.

Results

Analysis of the results supported the significant effect of estimation method, gender, cognitive condition of the subject and the interaction among method and cognitive condition factors in the measured ICV. Results on sub-sampling studies with a 95% confidence showed that in order to keep the accuracy of the interleaved slice sampling protocol above 99%, the sampling period cannot exceed 20 millimeters for AC and 15 millimeters for AD. Freesurfer showed promising estimates for both adult groups. However SPM showed more consistency in its ICV estimation over the different phases of the study.

Conclusions

This study emphasized the importance in selecting the appropriate protocol, the choice of the sampling period in the manual estimation of ICV and selection of suitable software for the automated estimation of ICV. The current study serves as an initial framework for establishing an appropriate protocol in both manual and automatic ICV estimations with different subject populations.

Comments

© 2015 Sargolzaei et al.; licensee BioMed Central Ltd.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

Recommended Citation

Sargolzaei et al.: A practical guideline for intracranial volume estimation in patients with Alzheimer’s disease. BMC Bioinformatics 2015 16(Suppl 7):S8.