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.
For the case when the detector is not placed next to the sample, such as when geometric magnification is being used, the calculation becomes: Ug = f* b/a. f = source focal-spot size. a = distance from x-ray source to front surface of material/object b = distance from the front surface of the object to the detector.n general, the allowable amount is 1/100 of the material thickness up to a maximum of 0.040 inch. These values refer to the degree of penumbra shadow in a radiographic image. Since the penumbra is not nearly as well defined as shown in the image to the right, it is difficult to measure it in a radiograph.