Hii, Aspirant...

No, after finishing a BSc in radiology, you cannot pursue a PhD in radiology.

A doctorate in radiology is a three-year full-time medical degree programme in radiology and radiological science.

The admissions process for Ph.D. Radiology is based on merit and an entrance examination. To pursue this programme, a student must have completed a DM or MD in Radiology course from any accredited university with a minimum of 55 percent aggregate of marks.

I hope you find this material useful.

Regards.