This could lead to serious problems that occur if clonidine is stopped suddenly. Previous versions of the prescribing information for clonidine tablets and patches stated that the medication was approved for use in children as young as 12 years old. The current prescribing information states that these medications are not approved for use in children.
Therefore whereas a dental x-ray room may require a. nominal shielding of about 1.5mm lead for the direct beam and. about 0.7mm lead for the scattered field, a diagnostic x-ray. room may require a nominal shielding of about 3mm and 1.5mm. for the direct beam and scattered field respectively.
The higher the energy of the gamma rays, the thicker the shielding made from the same shielding material is required. Materials for shielding gamma rays are typically measured by the thickness required to reduce the intensity of the gamma rays by one half (the half value layer or HVL).