TY - JOUR
T1 - Latent Transformer Models for out-of-distribution detection
AU - Graham, Mark S.
AU - Tudosiu, Petru Daniel
AU - Wright, Paul
AU - Pinaya, Walter Hugo Lopez
AU - Teikari, Petteri
AU - Patel, Ashay
AU - U-King-Im, Jean Marie
AU - Mah, Yee H.
AU - Teo, James T.
AU - Jäger, Hans Rolf
AU - Werring, David
AU - Rees, Geraint
AU - Nachev, Parashkev
AU - Ourselin, Sebastien
AU - Cardoso, M. Jorge
N1 - Funding Information:
MG, PW, WHLP, SO, PN and MJC are supported by a grant from the Wellcome Trust, United Kingdom ( WT213038/Z/18/Z ). MJC and SO are also supported by the Wellcome/EPSRC Centre for Medical Engineering ( WT203148/Z/16/Z ), and the InnovateUK-funded London AI centre for Value-based Healthcare . PN is also supported by NIHR UCLH Biomedical Research Centre . YM is supported by a grant from the Medical Research Council, United Kingdom ( MR/T005351/1 ). The models in this work were trained on NVIDIA Cambridge-1, the UK’s largest super-computer, aimed at accelerating digital biology.
Publisher Copyright:
© 2023 The Author(s)
PY - 2023/12
Y1 - 2023/12
N2 - Any clinically-deployed image-processing pipeline must be robust to the full range of inputs it may be presented with. One popular approach to this challenge is to develop predictive models that can provide a measure of their uncertainty. Another approach is to use generative modelling to quantify the likelihood of inputs. Inputs with a low enough likelihood are deemed to be out-of-distribution and are not presented to the downstream predictive model. In this work, we evaluate several approaches to segmentation with uncertainty for the task of segmenting bleeds in 3D CT of the head. We show that these models can fail catastrophically when operating in the far out-of-distribution domain, often providing predictions that are both highly confident and wrong. We propose to instead perform out-of-distribution detection using the Latent Transformer Model: a VQ-GAN is used to provide a highly compressed latent representation of the input volume, and a transformer is then used to estimate the likelihood of this compressed representation of the input. We demonstrate this approach can identify images that are both far- and near- out-of-distribution, as well as provide spatial maps that highlight the regions considered to be out-of-distribution. Furthermore, we find a strong relationship between an image's likelihood and the quality of a model's segmentation on it, demonstrating that this approach is viable for filtering out unsuitable images.
AB - Any clinically-deployed image-processing pipeline must be robust to the full range of inputs it may be presented with. One popular approach to this challenge is to develop predictive models that can provide a measure of their uncertainty. Another approach is to use generative modelling to quantify the likelihood of inputs. Inputs with a low enough likelihood are deemed to be out-of-distribution and are not presented to the downstream predictive model. In this work, we evaluate several approaches to segmentation with uncertainty for the task of segmenting bleeds in 3D CT of the head. We show that these models can fail catastrophically when operating in the far out-of-distribution domain, often providing predictions that are both highly confident and wrong. We propose to instead perform out-of-distribution detection using the Latent Transformer Model: a VQ-GAN is used to provide a highly compressed latent representation of the input volume, and a transformer is then used to estimate the likelihood of this compressed representation of the input. We demonstrate this approach can identify images that are both far- and near- out-of-distribution, as well as provide spatial maps that highlight the regions considered to be out-of-distribution. Furthermore, we find a strong relationship between an image's likelihood and the quality of a model's segmentation on it, demonstrating that this approach is viable for filtering out unsuitable images.
KW - Out-of-distribution detection
KW - Segmentation
KW - Transformers
KW - Uncertainty
UR - http://www.scopus.com/inward/record.url?scp=85173555884&partnerID=8YFLogxK
U2 - 10.1016/j.media.2023.102967
DO - 10.1016/j.media.2023.102967
M3 - Article
AN - SCOPUS:85173555884
SN - 1361-8415
VL - 90
JO - Medical Image Analysis
JF - Medical Image Analysis
M1 - 102967
ER -