Diagnosis Flashcards
The occurance of a low-trauma fracture without alternative eplanation is diagonstic of?
osteoporosis
NO matter wat the bone denstity test shows
what is the mainstay of diagnosing and monitoring osteoporosis?
Duel-energy X-ray absorptiometry (DXA)
what does the T score mean
states how many standard deviations that a pts BMD is from the mean of a population of sex-matched young, healthy controls
what does a Z score mean
it is the same thing as a T score, except the reference population is age matched
What should be kept in mind when diagnosing a young patient with osteoporosis?
the diagnosis of osteoporosis in young patients should be reserved for those with fragility fractures and should not be made on DXA Alone
a T score of -2.5 or lower?
osteoporosis
a T score of -1.0 to -2.4
osteopenia
For the purpose of diagnosis, what site is used for scoring?
The site that shows an individual’s lowest score
What score is used in both premenopausal women and young men?
Z-scores
A Z-score less than -2.0 in premenopausal women and young men?
lower than expeced bone density for age
useful for accurately determining size of gland and nodules- can also evaluate texture of gland
thyroid ultrasound
when do you perform fine needle aspiration?
nodules must be 1cm to biopsy
limitation to fine needle aspiration?
cannot differentiate follicular adenoma from follicular carcinoma
what do you obtain if TSH is low or FNA shows evidence of follicular neooplasia?
thyroid scan
what results could come back for thyroid scan?
Cold: nonfunctioning (5-10% risk of malignancy)
Warm: Functioning (5-10% risk of malignancy)
Hot: hyperfunctioning, rarely malingant
diagnosis of cushing’s syndrome
24 hour urine cortisol (at least 2 tests)
dexmethasone supression testing (negative feedback- supressibility) (excess steroid should shut off ACTH if it doesn’t thats supporting)
midnight salivary cortisol x 2-3 (Circadian rhythm)
Dexmethasone supression test
1mg of dex taken at midnight- cortisol levels taken in the AM.
Less than 1.8 ug/dL excludes cushing’s
*make sure patient isn’t on OCPs)
How do you distingush between ACTH-dependent and independent causes by ordering AM plasma ACTH? what levels would you expect? what would be important to look at?
- plasma ACTH undetectable would be ACTH independent form of cushings- look at adrenals
- Plasma ACTH normal or elevated - ACTH dependent form of cushing’s- look at pituitary gland or ectopic source
Imaging studies for cushing’s syndrome?
Pituitary MRI (Cushing’s disease)- depenent ACTH
CT of Adrenals- (Independent ACTH)
CT of thorax (if MRI doesn’t show anything)
what is first line treatment for cushing’s syndrome
pituitary surgery is the first-line treatment of cushing’s disease
what is first line treatment for cushing’s syndrome
pituitary surgery is the first-line treatment of cushing’s disease
how do you confirm the diagnosis of primary aldosteronism?
what is a normal result? what is hyperaldosteronism?
- IV normal saline suppression test: 2-3 liters infused over 4-6 hours
- normal= aldosterone after IV NS<6ng/dl
- Hyperaldosteronism confirmed if PA> 10ng
how do you diagnose pheochromocytoma?
measure metanephrines and catecholamines in urine and blood
24 hour urine for a phechromocytoma workup measures? (98% sensitive, 98% specific)
fractionated metenephrines
fractionated catecholamines
