Time-Dependent Diffusion MRI Reveals Smaller Cell Size with Stable Volume in Hippocampus and Amygdala during Chemotherapy

Motivation: Chemotherapy can cause cognitive impairment in breast cancer patients. However, the microstructural changes in hippocampus and amygdala during chemotherapy remain unknown. Goal(s): To explore the patterns of microstructural changes of hippocampus and amygdala during chemotherapy. Approach: Volume on T1-weighted imaging and microstructure estimated by JOINT model in hippocampus and amygdala of 37 female breast cancer patients were recorded at baseline (T0), after the first (T1), and sixth (T6) or eighth (T8) cycle of neoadjuvant chemotherapy. Results: Bilateral hippocampus and amygdala have smaller cell size without volume change in breast cancer patients receiving neoadjuvant chemotherapy. Impact: By combining Time-Dependent Diffusion MRI and 3D T1WI MRI, a decrease in cell sizes with unchanged volume of hippocampus and amygdala among breast cancer patients was identified with repeated measurements during neoadjuvant chemotherapy, aiding early diagnosis and treatment of chemo-brain.