<prompt> Safest radiological investigation in pregnancy is-CTMRIX-rayHRCT  <response>: Ans is b i.e. MRI The American college of radiology ACR advices that pregnant patients can undergo MRI without risks for the fetus - MRI of fetal and maternal diseases in pregnancy; p 439Other advantaged and disadvantages of MRIAdvantagesDisadvantages Static and cine or movie images Multiple plane images Good contrast No known health hazard No ionizing radiation Excellent soft tissue differentiation Good for soft tissue injuries of knee, ankle, shoulder Better than CT in visualizing vascular structures More expensive than CT Long scan time may result in motion artifacts Limited availability Not good for calcified lesions and bone CT is better 