If the central ray is perpendicular to the film but not to the object, then:
Correct Answer: Foreshortening of the image occurs
Description: Image shape distortion is minimized when the long axes of the image receptor and tooth are parallel.
Figure A shows that the central ray of the X-ray beam is perpendicular to the image receptor, but the object is not parallel to the image receptor. The resultant image is distorted because of the unequal distances of the various parts of the object from the image receptor. This type of shape distortion is called foreshortening, because it causes the radiographic image to be shorter than the object.
Figure B shows the situation when the X-ray beam is oriented at right angles to the object, but not to the image receptor. This results in elongation, with the object appearing longer on the image receptor than its actual length.
Category:
Radiology
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now