Radiology Grade

The medical student was shocked when he received a failing grade in radiology. Approaching the professor, he demanded to know the reason for the grade. "You know the self X-ray you took?" asked the professor. "I do." "A fine picture," he said, "of your lungs, stomach, and liver." "If it's a fine picture, then why did you give me an F?" "I had no choice," said the professor. "You didn't put your heart into it."