When the patient is you or a loved one, sometimes you have to risk offending the doctor and tell them you would like a second opinion. This is your right as a patient and your obligation as an adult managing your own medical care as best you can.
Like any other professional, Doctors and Nurse Practitioners can get stuck in ruts too, generalizing symptoms and treating them as has always been done before. Your case, your innards may be the exception to the generalization. A confident medical provider of care should not be threatened by timely and prudent hesitation of a patient.
NSF is no joke. The approved dosage for gadolinium have been drastically cut for everyone in recent years. Regardless of renal function. It used to be common practice to give double doses for exams like MRA necks.