Changes of apoptosis in tumor tissues with time after irreversible electroporation.

•Irreversible electroporation has caused aggressive apoptosis in tumor tissues.•The occurrence of apoptosis has been changed with time.•We demonstrate a peak of apoptotic rate at 24h after electroporation.•In contrast-enhanced MR images, devascularization appear to be no enhancement as apoptotic or necrotic process.•This apoptosis may play significant roles on therapeutic process by electroporation.