In vitro detection of apoptosis using oscillating and pulsed gradient diffusion magnetic resonance imaging

Area of Science:

• Biophysics
• Medical Imaging
• Cancer Research

Background:

• Radiotherapy and chemotherapy induce apoptosis for tumor regression.
• Early detection of apoptosis can improve assessment of treatment response compared to tumor volume measurements.

Purpose of the Study:

• To investigate the microstructural effects of apoptosis using diffusion experiments.
• To develop imaging methods for non-invasive apoptosis detection and monitoring of therapeutic response.

Main Methods:

• Diffusion experiments were conducted on acute myeloid leukemia cell pellets treated with cisplatin to induce apoptosis.
• Pulsed and oscillating gradient diffusion measurements were used to assess microstructural changes.
• Data were fitted to the parallel plane model to quantify diffusion parameters (d, Dfree, Drest).

Main Results:

• Apoptosis significantly altered diffusion properties, confirmed by TUNEL staining.
• Apoptotic samples showed decreased restricted size (d) and free diffusion coefficient (Dfree).
• A significant increase in the restricted diffusion coefficient (Drest) was observed in apoptotic samples.

Conclusions:

• Observed diffusion changes correlate with known morphological effects of apoptosis, such as cell shrinkage and increased extracellular volume.
• Diffusion MRI methods can non-invasively detect apoptosis, potentially improving therapeutic response monitoring.
• These methods may differentiate apoptosis from other cell death types like necrosis.