Hypernetwork-Based Adaptive Aggregation for Multimodal Multiple-Instance Learning in Predicting Coronary Calcium Debulking
Kaito Shiku, Ichika Seo, Tetsuya Matoba, Rissei Hino, Yasuhiro Nakano, Ryoma Bise
TL;DR
The paper tackles predicting the need for debulking devices in calcified coronary lesions using preoperative CT, formulating the task as multimodal MIL where a bag of vessel-slice instances is paired with patient tabular data. It introduces HyperAdAgFormer, a hypernetwork-conditioned Transformer that outputs Tabular-conditioned Transformation Parameters $\mathbf{v}^i$ and patient-specific classifier weights $\mathbf{W}^i,\mathbf{b}^i$, enabling adaptive aggregation via the token $\tilde{\mathbf{a}}^i=\mathbf{a}+\mathbf{v}^i$. The approach achieves superior bag-level prediction on a private clinical dataset (AUC $=0.710$, F1 $=0.570$) compared with unimodal MIL and several multimodal baselines, underscoring the value of conditioning aggregation on sparse tabular data. This work offers a practical pathway for preoperative assessment of device necessity and introduces a flexible framework for context-aware MIL in medical imaging.
Abstract
In this paper, we present the first attempt to estimate the necessity of debulking coronary artery calcifications from computed tomography (CT) images. We formulate this task as a Multiple-instance Learning (MIL) problem. The difficulty of this task lies in that physicians adjust their focus and decision criteria for device usage according to tabular data representing each patient's condition. To address this issue, we propose a hypernetwork-based adaptive aggregation transformer (HyperAdAgFormer), which adaptively modifies the feature aggregation strategy for each patient based on tabular data through a hypernetwork. The experiments using the clinical dataset demonstrated the effectiveness of HyperAdAgFormer. The code is publicly available at https://github.com/Shiku-Kaito/HyperAdAgFormer.
