Collimators that offer positive beam limitation (PBL) are very popular with technologists for a variety of reasons. Even though the federal requirement for PBL has been repealed, their popularity has continued and most department managers consider PBL as a 1cstandard equipment 1d feature. PBL is electronically and mechanically highly engineered technology and subject to abuse by the inattentive and unprofessional radiographer. In the event of a PBL failure during an examination, what circumstances will be evident to the radiographer and what can he/she do to overcome the PBL error and continue with the procedure.

Question

What will be an ideal response?

Answer 1

Malfunctioning PBL will not put the collimation into the 1cPositive 1d mode and therefore the exposure will be prevented. With PBL, the receptor size and the x-ray field size must match each other in dimension to be in the positive mode. Your field size can be smaller than the receptor size and still be in the positive mode. Under this circumstance, exposure will be permitted. If the PBL is not in positive mode due to malfunction, a 1ckey 1d may be turned to bypass the PBL sensing technology. This will allow the radiographer to operate the collimation in the manual mode. If this occurs, collimation may be done manually and should not exceed the dimension of the receptor.The exposure will be permitted in the manual mode. Following the examination, the malfunction should be reported to department leadership for repair.