M3CoTBench: Benchmark Chain-of-Thought of MLLMs in Medical Image Understanding - Jiang, Juntao; Zhang, Jiangning; bi, Yali; Jinsheng, BAI; Liu, Weixuan; Jin, Weiwei; Xue, Zhucun; Liu, Yong; Hu, Xiaobin; YAN, Shuicheng (International Conference on Learning Representations, 2026)