Quantifying Biomechanical Properties from Dynamic Imaging

Deformable image registration (DIR) algorithms can be used to recover the motion of objects (i.e. organs) depicted within a temporal series of anatomical images (dynamic imaging). Functional properties of the imaged organ or tissue are then inferred from the information embedded within the DIR solution (recovered motion) and the underlying image data. For example, one of the lab’s current research directions focuses on further developing Computed Tomography-Derived Functional Imaging (CT-FI). CT-FI is an image processing-based modality that employs mathematical modeling and scientific computing to generate quantifiable surrogates for pulmonary ventilation and perfusion from dynamic computed tomography. The figures above show the results from the CT-FI Perfusion estimate (left) and the actual nuclear medicine perfusion image (right).

Selected Publications on Functional Imaging

Yi-Kuan Liu, Hsu-Ting Kuo, Alaa Melek, Richard Castillo, Yevgeniy Vinogradskiy, Lili Zhao, Girish Nair and Edward Castillo. Predicting Ventilation from Single Breathing Phase Non-Contrast CT Using Swin Transformers. Medical Physics. 54:e70406, 2026.

Yi-Kuan Liu, Jorge Cisneros, Girish Nair, Craig Stevens, Richard Castillo, Yevgeniy Vinogradskiy, and Edward Castillo. Perfusion Estimation from Dynamic Non-Contrast Computed Tomography Using Unsupervised Learning and a Physics-Inspired U-Net Transformer Architecture. International Journal of Computer Assisted Radiology and Surgery. 20: 959-970, 2025.

Girish Nair, Sayf Al-Katib, Robert Podolsky, Thomas Quinn, Craig Stevens, and Edward Castillo. Dynamic Lung Compliance Imaging from 4DCT-Derived Volume Change Estimation. Physics in Medicine and Biology, 66(21): 21NT06, 2021.

Edward Castillo, Girish Nair, Danielle Turner-Lawrence, Nicholas Myziuk, Scott Emerson, Sayf Al-Katib, Sarah Westergaard, Richard Castillo, Yevgeniy Vinogradskiy, Thomas Quinn, Thomas Guerrero, and Craig Stevens. Quantifying Pulmonary Perfusion from Non-Contrast Computed Tomography. Medical Physics, 48: 1804-1814, 2021.

Edward Castillo, Yevgeniy Vinogradskiy, and Richard Castillo. Robust HU-Based CT-Ventilation from an Integrated Mass Conservation Formulation. Medical Physics. 46(11): 5036-5046, 2019. (Editor’s Choice Featured Article)