CT with fusion is a radiological technique used to enhance the images. It does not imply the use of a contrast agent. I'm not a radiologist but I believe it has to do with overlaying the images in a particular manner and the use of specialized software.
The procedure itself should not be different from your point of view.
It is the responsibility of your doctor to "rule out the worst possibility" even if they believe your problem is
benignBenign ear cyst or tumor
Benign positional vertigo or
inflammatoryInflammatory bowel disease
Ulcerative colitis. From what you have written, it appears as though they are doing just that!
Information contained within this reply is intended solely for general educational purposes and is not intended nor implied to be a medical diagnosis or treatment recommendation. This is not a substitute for professional medical advice relative to your specific medical condition or question. Always seek the advice of your own doctor for medical condition. Only your doctor can provide specific diagnoses and therapies.