Establishment of exposure conditions for thoracic radiography in dairy cattle using a portable X-ray apparatus

Exposure conditions for thoracic radiography using a portable X-ray apparatus were established in 36 healthy cow. The following results were obtained: (1) Radiography using a portable X-ray apparatus with rare earth high speed screens and high speed films revealed clear thoracic images with good quality. (2) The exposure index (I') calculated based on the X-ray intensity (I) enabled to design a table for determination of exposure conditions. (3) The exposure conditions must be changed depending on the body condition score (BCS). Comparing with the exposure conditions of the cow with BCS 3.0, those of the cow BCS 2.5 were approximately 70% and those of the cow with BCS 3.5 were approximately 120% when their chest breadth was the same