40% of patients with CD will have a normal MRI

[trs]

I found it interesting that this article says 40% of patients with CD will have a normal MRI.

This is a long article, I just copied the last paragraph and posted it here.

 

http://jcem.endojournals.org/cgi/content/full/87/4/1640

 

Optimal Response Criteria for the Human CRH Test in the Differential Diagnosis of ACTH-Dependent Cushing?s Syndrome

 

("By themselves, none of the noninvasive or dynamic tests used for the differential diagnosis of ACTH-dependent CS are completely reliable, and several tests may need to be used. If the hCRH test shows a rise above 20% in serum cortisol at 15 and 30 min, EC is very unlikely. However, the sensitivity of the test, in either its oCRH or hCRH form, for CD is still significantly less than 100%. What then are the recommendations for the use of the test in clinical practice? Bilateral inferior petrosal sinus sampling (BIPSS) remains the gold standard for establishing whether there is a central to peripheral gradient of plasma ACTH consistent with CD, with a sensitivity of 95?100% with a specificity of virtually 100% in major centers (1). This is, however, an invasive test requiring considerable expertise in specialist centers, and some clinicians will only option for it in cases of doubt. Forty percent of patients with CD will have a normal pituitary magnetic resonance image, whereas conversely there is a 10% prevalence of pituitary incidentalomas in the age range in which CD typically presents (1). It is, therefore, clear that magnetic resonance imaging of the pituitary cannot be relied on and weight should be given to the biochemical evaluation of a given patient. With a clear response to hCRH and an obvious pituitary lesion with stalk deviation, BIPSS may not be needed. An additional advantage of the hCRH test is that if plasma ACTH is also measured a persistently undetectable ACTH will confirm ACTH independence and the primacy of adrenal pathology (1). However, given the problems in interpreting any dynamic test in isolation, we currently consider that BIPSS or cavernous sinus sampling will continue to be necessary in the great majority of patients.")

[regalgal]

this is very good information...I think I will be using this. ALthough my local endo is very good...he may not agre with the continued testing..even though Dr F. wants it...but i should say, he will work along with it.

-However, my last visit with him, left me feeling uncomfy regarding his approach to continued testing...he said that he wonders if I will be satisfied and accept the findings, if my next Mri shows no difinitive tumor. I told him, that depends on how I feel. He seemed a bit irritated with me.

 

He has some very good points, that I am willing to listen to and try with him...such as the possibility that the four years of being on cytomel could have screwed up my thyroid..and that my thyroid is now trying to recover some of it's function..and as it does....there could well be some "unmasking" of the other hormone levels that will need to be addressed.....ONe by ONe. ANd he urges me to be patient in giving my thyroid some time to recover and get used to taking only synthroid.(Dr F. is in agreement with this being a reasonable approach)......so I am giving it a few months, before weaning further from cortef,......holding off a bit more on the testing for cyclical....

But i have the requisitions from Dr F. to do it when it is time to do it.

 

Oh I am rambling..I should just make a new post.....but Trish...thanks for this article..it helps..that was my first point!

 

LoriJane