Development and evaluation of an algorithm for the computer-assisted segmentation of the human hypothalamus on 7-Tesla magnetic resonance images.
Post mortem studies have shown volume changes of the hypothalamus in psychiatric patients. With 7T magnetic resonance imaging this effect can now be investigated in vivo in detail. To benefit from the sub-millimeter resolution requires an improved segmentation procedure. The traditional anatomical landmarks of the hypothalamus were refined using 7T T1-weighted magnetic resonance images. A detailed segmentation algorithm (unilateral hypothalamus) was developed for colour-coded, histogram-matched images, and evaluated in a sample of 10 subjects. Test-retest and inter-rater reliabilities were estimated in terms of intraclass-correlation coefficients (ICC) and Dice's coefficient (DC). The computer-assisted segmentation algorithm ensured test-retest reliabilities of ICC≥.97 (DC≥96.8) and inter-rater reliabilities of ICC≥.94 (DC = 95.2). There were no significant volume differences between the segmentation runs, raters, and hemispheres. The estimated volumes of the hypothalamus lie within the range of previous histological and neuroimaging results. We present a computer-assisted algorithm for the manual segmentation of the human hypothalamus using T1-weighted 7T magnetic resonance imaging. Providing very high test-retest and inter-rater reliabilities, it outperforms former procedures established at 1.5T and 3T magnetic resonance images and thus can serve as a gold standard for future automated procedures.
Department of Psychiatry and Psychotherapy, University Hospital Leipzig, Leipzig, Germany.
Stephanie
S
Schindler
Peter
P
Schönknecht
Laura
L
Schmidt
Alfred
A
Anwander
Maria
M
Strauß
Robert
R
Trampel
Pierre-Louis
PL
Bazin
Harald E
HE
Möller
Ulrich
U
Hegerl
Robert
R
Turner
Stefan
S
Geyer
D000328:Adult; D000465:Algorithms; D059925:Anatomic Landmarks; D003116:Color; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000033:anatomy & histology*; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009929:Organ Size; D015203:Reproducibility of Results