High-fidelity label-free 3D microscopy via Fourier ptychographic diffraction tomography with adaptive support constraint

Diffraction tomography fundamentally suffers from the missing-cone problem, resulting in severe axial elongation, refractive index (RI) underestimation, and structural cross-talk. Here, we introduce Fourier ptychographic diffraction tomography with adaptive support constraint (FPDT-ASC), a physically grounded framework that exploits the finite spatial extent of the specimen to recover missing spectral information. By jointly refining the RI distribution and the support mask via a random-walk-with-restart strategy, FPDT-ASC enables artifact-free reconstruction without requiring additional measurements. Experimental validation on HeLa cells demonstrates that FPDT-ASC achieves high-fidelity, quantitatively accurate RI reconstruction.