AI-assisted quantification of hypothalamic atrophy in amyotrophic lateral sclerosis by convolutional neural network-based automatic segmentation

Abstract

The hypothalamus is a small structure of the brain with an essential role in metabolic homeostasis, sleep regulation, and body temperature control. Some neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and dementia syndromes are reported to be related to hypothalamic volume alterations. Despite its crucial role in human body regulation, neuroimaging studies of this structure are rather scarce due to work-intensive operator-dependent manual delineations from MRI and lack of automated segmentation tools. In this study we present a fully automatic approach based on deep convolutional neural networks (CNN) for hypothalamic segmentation and volume quantification. We applied CNN of U-Net architecture with EfficientNetB0 backbone to allow for accurate automatic hypothalamic segmentation in seconds on a GPU. We further applied our approach for the quantification of the normalized hypothalamic volumes to a large neuroimaging dataset of 432 ALS patients and 112 healthy controls (without the ground truth labels). Using the automated volumetric analysis, we could reproduce hypothalamic atrophy findings associated with ALS by detecting significant volume differences between ALS patients and controls at the group level. In conclusion, a fast and unbiased AI-assisted hypothalamic quantification method is introduced in this study (whose acceptance rate based on the outlier removal strategy was estimated to be above 95%) and made publicly available for researchers interested in the conduction of hypothalamus studies at a large scale.

Volume loss in the left anterior‐superior subunit of the hypothalamus in amyotrophic lateral sclerosis

“… 3 , 30 , 33 , 35 , 36 , 37 This state impacts patient well‐being and survival, and one of the investigated causes includes altered hypothalamic physiology. 15 , 17 , 23 , 38 , 39 Notably, our findings on the atrophy of the left a‐sHyp in the presumably dominant hemisphere in ALS patients replicated and supported previous findings, 22 , 23 marked overall hypothalamic atrophy and disrupted connectivity, 7 , 15 , 17 , 21 , 39 , 40 , 41 and bvFTD, 42 , 43 indicating the specific vulnerability of this region. This finding specifies a‐sHyp involvement and highlights a target for further studies.…”