"Referral by ENT consultant For MRI"

i was referred for an MRI scan by my ENT Consultant at RSH twice..the first referral i received a CT scan.. then a few weeks after i received a letter from my Consultant apologizing for forgetting to refer me for the MRI scan and would do it straight away and i would receive an appointment through the post in the near future..I did receive my appointment from Radiology Department of the RSH for a CT scan..a bit bewildered and confused i rang the radiology department asking if they had received referrals for me from my Consultant for MRI scans and they confirmed they had had two referrals for me .Then i asked if MRI scans and CT scans were the same thing and was told no they are different..so i asked why i had been given appointments for CT scans and not as the consultant requested

MRI scans ..I was told the radiologists had decided i only needed a CT scan ....is this correct procedure for other departments to overrule what consultants decide you will need in order for them to diagnose patients properly ??i obviously cancelled the second CT scan appointment as i did,nt want the nhs to waste valuable time and money on a test they had already done two weeks previously, i still have the loud heart beat sound continuously in my left ear and the continual tinnitus which is now accompanied by a constant dull headache on the left side of my head but don,t see the point in trying to get another referral ..i,m at a loss as to what to do now and have recently been informed i have cerebral vascular disease along with a myriad of other illnesses that are and have plagued me for the last few years .