The diagnostic test of choice is?

Question

8: A 30-year-old woman is found to have a low serum thyroxine level after being evaluated for fatigue. Five years ago she was treated for Graves disease with radioactive iodine. The diagnostic test of choice is
a. Serum TSH
b. Serum T3
c. SerumT4
d. TRH stimulation test
e. Radioactive iodine uptake

Answer 1

The patient likely has hypothyroidism post-radioactive iodine, which a high TSH (A) would confirm.

T3 and T4 would already tell you that she has low thyroid hormone, but not why. TRH stimulation test only useful if TSH is low ie pituitary cause of hypothyroidism.

Radioactive iodine uptake would be low - but that would also be expected and does not tell you the thyroid *hormone* status

Answer 2

The diagnosis is already essentially made.
The patient has a low thyroxine status-post radio-ablation for Graves disease and is hypothyroid.

The TSH will help distinguish whether the low thyroid hormone is caused by primary pituitary or by a primary thyroid disease. With this patient's history it is almost certain that the thyroid ablation is responsible.

One possible factor that is not mentioned in the given info, that might figure in real life, is whether the patient is already taking supplementary thyroid hormone, in which case the TSH might be suppressed. In this problem, the patient's fatigue and low thyroid might be due to an inadquate dose of replacement hormone.

a. serum TSH is the best answer

Answer 3

Any competent cardiologist can find out quickly about the status of the natural valves of the heart caused by disease. There is no single test of choice. The cardiologist will decide upon a graduated sequence of tests depending on the merits of each case. This will start with a OPD discussion, and can go on in stages through ECG, treadmill, Holter monitoring, Plain and Doppler ultra-sonogram, plain/cine angiography, and cardiac catheterization. This can be in addition to routine biochemical tests. Prosthetic valves do not get diseased since they are man-made devices. If they were improperly sterilized, the recipient may end up with bacterial endocarditis. This is rare and in any case is not a disease of the prosthesis. It is of course possible that the prosthesis is causing thrombo-embolism or excessive Haemolysis. These again are not diseases but due to poor biocompatibility or mechanical problems. Sometimes it also happens because the patient is not strictly adhering to the drug regimen given to him/her at discharge from the hospital. There are standard post-operative follow up procedures for monitoring the performance of Cardiac valvular prostheses.

Answer 4

Serum TSH

Answer 5

If this woman was my patient,I would ask for more details to answers this question.With those details,she will probably not need to undergo this diagnostic test.
But with only these details,TRH stimulation test is advised.
If TRH stimulates,it means hypothalamic patholgy
If it fails to stimulate,Pituitary Pathology likely

Answer 6

SERUM TSH

Answer 7

serum TSH..

Answer 8

a