Fallopian tube spasm is a transient functional anomaly that can mimic a true mechanical tubal occlusion. At radiography, tubal spasm cannot be distinguished from a tubal occlusion. Administration of spasmolytic agents such as glucagon can occasionally result in uterine muscle relaxation and consequent tube opacification, thereby helping differentiate a spasm from true occlusion 1. Delayed radiography may also be performed to help differentiate tubal spasm from a true tubal occlusion.