What does increased radiopharmaceutical uptake in the spinous processes mean?

The article discusses the impact of increased radiopharmaceutical uptake (IRU) in the spinous processes. It mentions about correlation between imaging techniques such as radiography and scintigraphy for horses with back pain; and back pain can arise from spinal lesions and or musculature pain. It also mentions about pathology affecting the spinous processes and the presence of abnormalities in both imaging modalities.