Operationalizing protocol differences for EADC-ADNI manual hippocampal segmentation.

Publication Type:

Journal Article

Authors:

Boccardi, Marina; Bocchetta, Martina; Ganzola, Rossana; Robitaille, Nicolas; Redolfi, Alberto; Simon Duchesne; Jack, Clifford R; Frisoni, Giovanni B

Source:

Alzheimers Dement, Volume 11, Issue 2, p.184-94 (2015)

Keywords:

Aged, Alzheimer Disease, Atrophy, Delphi Technique, Female, Hippocampus, Humans, Image Processing, Computer-Assisted, Imaging, Three-Dimensional, Magnetic Resonance Imaging, Male, Mild Cognitive Impairment, Neuroimaging, Organ Size, Reproducibility of Results

Abstract:

BACKGROUND: Hippocampal volumetry on magnetic resonance imaging is recognized as an Alzheimer's disease (AD) biomarker, and manual segmentation is the gold standard for measurement. However, a standard procedure is lacking. We operationalize and quantitate landmark differences to help a Delphi panel converge on a set of landmarks.METHODS: One hundred percent of anatomic landmark variability across 12 different protocols for manual segmentation was reduced into four segmentation units (the minimum hippocampus, the alveus/fimbria, the tail, and the subiculum), which were segmented on magnetic resonance images by expert raters to estimate reliability and AD-related atrophy.RESULTS: Intra- and interrater reliability were more than 0.96 and 0.92, respectively, except for the alveus/fimbria, which were 0.86 and 0.77, respectively. Of all AD-related atrophy, the minimum hippocampus contributed to 67%; tail, 24%; alveus/fimbria, 4%; and the subiculum, 5%.CONCLUSIONS: Anatomic landmark variability in available protocols can be reduced to four discrete and measurable segmentation units. Their quantitative assessment will help a Delphi panel to define a set of landmarks for a harmonized protocol.