Radiation exposure is least in
MCU : 1 - 2 (msv) - 60 chest x - ray.
Cystography : 1- 8 (msievert) - 90cxr.
IVP : 2 - 4 - 120cxr.
CT pelvis : 10 - 500cxr.
CT pelvis
IVP
Cystography
Micturating cysto - Urethrogram