Final answer:
The most sensitive additional test to detect ped spondylolysis after a normal ap lat x-ray is a bone scan, also known as nuclear medicine imaging.
Step-by-step explanation:
The additional test that is most sensitive to detect ped spondylolysis after normal ap lat xray is a bone scan, also known as nuclear medicine imaging.
A bone scan uses a small amount of radioactive material that is injected into the patient's bloodstream. This material is taken up by the bones, allowing for the detection of areas of increased bone activity.
In the case of ped spondylolysis, which is a stress fracture of the pars interarticularis in the spine, a bone scan can show increased uptake in the affected area, even if it is not visible on a regular X-ray.