Operationalizing protocol differences for EADC-ADNI manual hippocampal segmentation

• Published in: Alzheimer's & dementia Vol. 11; no. 2; pp. 184 - 194
• Main Authors: Boccardi, Marina, Bocchetta, Martina, Ganzola, Rossana, Robitaille, Nicolas, Redolfi, Alberto, Duchesne, Simon, Jack, Clifford R, Frisoni, Giovanni B
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-02-2015
• Subjects: Aged; Alzheimer Disease - pathology; Alzheimer's disease; Alzheimer's Disease Neuroimaging Initiative; Anatomic landmark; Atrophy; Cognitive Dysfunction - pathology; Degeneration; Delphi Technique; Female; Harmonization; Hippocampal atrophy; Hippocampal volumetry; Hippocampus; Hippocampus - anatomy & histology; Hippocampus - pathology; Humans; Image Processing, Computer-Assisted - methods; Imaging, Three-Dimensional - methods; Magnetic resonance; Magnetic Resonance Imaging - instrumentation; Magnetic Resonance Imaging - methods; Male; Manual segmentation protocol; Manual tracing; Medial temporal lobes; Neuroimaging; Neuroimaging - methods; Neurology; Organ Size; Reproducibility of Results; Standard operating procedures; Neuroimaging; Manual tracing; Magnetic resonance; Standard operating procedures; Manual segmentation protocol; Anatomic landmark; Hippocampal volumetry; Hippocampal atrophy; Harmonization; Atrophy; Alzheimer's Disease Neuroimaging Initiative; Degeneration; Medial temporal lobes; Alzheimer's disease; Hippocampus
• ISSN: 1552-5260; 1552-5279
• DOI: 10.1016/j.jalz.2013.03.001

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.