Anteroposterior (AP) lumbar radiographic examinations require optimal exposure factorsrnto produce high-quality images while minimizing radiation dose in accordance with the ALARA (AsrnLow As Reasonably Achievable) principle. In this matter, the Rule of Thumb theory adjustsrnkilovoltage (kV) based on the variations in the object thickness to achieve an optimal DeviationrnIndex (DI) value in AP …