Abstract: A radiological scaling device for use in determining a size of an anatomic structure on an X-ray image comprises a radio-opaque member having a predetermined known length, and first and second radio-lucent visualization gaps provided in the radio-opaque member. The radio-opaque member may be incorporated in a handle device or a catheter device such that the radio-opaque member may manipulated to be aligned in substantially a same plane as the anatomic structure between an X-ray tube and a film, and substantially perpendicular to an X-ray beam emitted by the X-ray tube. An X-ray image is produced which includes first and second gaps corresponding to the first and second radio-lucent visualization gaps of the radio-opaque member to thereby confirm that the radio-opaque member has been properly aligned substantially perpendicular to the X-ray beam.