Which of the following is associated with the least radiation in pregnancy?: (A) X-ray, (B) MRI, (C) CTscan, (D) VQscan
Answer is B. Ans: b (MRI) Ref: Practical Radiotherapy- physics ami equipment 2nd ed/p.68MRI uses magnetic properties of hydrogen atoms to generate images.Increasing order of radiation:-X-ray< VQ scan < CT scan.