Endo Imaging Flashcards
What “end organs” are affected by alterations in the pituitary?
- Thyroid
- Adrenals
- Gonads
- Breasts
Give 2 examples of altered trophic hormone (TH) production
- increased levels of TH’s leads to altered target gland function
- increased pituitary size leads to encroachment and/or pressure causing vision changes and HA
List the 6 hormones produced by the anterior pituitary
-Growth Hormone
-Prolactin
-Adrenocorticotropic Hormone
-Thyroid Stimulating Hormone (TSH)
-Luteinizing Hormone (LH)
♂ - Leydig cells/testosterone
♀ - Ovulation/corpus luteum
-Follicle Stimulating Hormone (FSH)
♂ - Spermatogenesis
♀ - Follicle development/estrogen
List the 2 hormones produced by posterior pituitary
- Arginine Vasopressin (ADH)
- Oxytocin
What is the name of the anatomical location of the pituitary gland?
Sella turcica
Causes of pituitary failure
-idiopathic
- Usually infiltrative process
- Lymphoma, Hodgkin’s, Sarcoid
Causes of pituitary failure
-Sheehan’s syndrome
Postpartum Hypotension: pressures drop low enough and for long enough to infarct the pituitary
-Could affect only a portion of the pituitary
Causes of pituitary failure
-Pituitary Apoplexy
- Infarct
- Fever: likely viral infection rather than fever itself
List the hormones produced by the thyroid
- TSH-Controlled (from Anterior Pituitary)
- T3 – active hormone
- T4 – primary product
- rT3 – not physiologically active
Which conditions can cause development of a goiter?
- hyperthyroidism
- hypothyroidism
- euthyroidism
Symptoms of hyperthyroidism
- Diaphoresis
- Heat Intolerance
- Cardiac Awareness (palpitations)
- Weight Loss
- Hair Thinning
- Skin Hyperpigmentation
Physical findings of hyperthyroidism
- Goiter – diffuse enlargement
- Nodule – Hot vs. Cold
- Tachycardia
- Hair Thinning
- Exophthalmos
- -Extra-ocular muscle and retro-ocular connective tissue volume increased (uni/bilateral)
- -Fibroblast proliferation, inflammation, and the accumulation of hydrophilic glycosaminoglycans (GAG), mostly hyaluronic acid
Symptoms of hypothyroidism
- Fatigue &/o Lethargy
- Weight Gain
- Cold Intolerance
- Paresthesias
- Sexual Dysfunction (primarily in men)
Physical findings of hypothyroidism
- Hair Loss
- Skin thickening
- Can be more difficult to discern in men
- Low Pitched Voice
- Facial edema
- Slow DTR (deep tendon reflex) return
Thyroid nodules
-cyst vs. solid
Proper vocabulary to use is:
- Solid = nodule
- Cyst = fluid-filled bump
- Solid is more likely to be cancer
- Evaluate posterior structures such as the parathyroids
What do you see on a normal Thyroid I123 or I131 Scan?
- 2 lobes
- Homogenous activity
- Isthmus
“Marker”
- -At the SC Notch
- -Check for mediastinal extension
Your patient has I123 administered. The radiologist contacts you to state that the nodule you felt is a “cold” nodule. What does this mean?
- Cold means it didn’t take up the iodine and it’s a nodule.
- The patient has an increased risk of thyroid cancer in the cold nodule.
Etiology of “cold” thyroid nodule
- ~ 90% of “lumps” are benign cysts or nodules
- 75-90% of all nodules are “cold”
- Most cancers are “cold” (~5-10% of cold nodules)
Will a cold nodule or a cyst take up the iodine for I123 scan?
No, neither will take it up. You must FNA “cold” nodule or excise the entire lobe.
Etiology of thyroid “hot” nodule
- aka “autonomous” nodule
- right lobe
- low risk of cancer
Will a hot nodule take up the iodine for I123 scan?
Yes, but reduced overall I123 update d/t suppressed TSH
Dx of hot nodule
FNA vs. surgical excision
Tx of hot nodule
I131 “burns” out nodule or multinodular goiter
Parathyroid adenoma is usually a disease of…
overactivity (i.e. increased PTH)
Sx of parathyroid adenoma
- Bone pain: Osteopenia on X-rays of hands & clavicles
- Weakness; Anorexia; Wt. Loss; Fatigue; Confusion/ Ψ
Tx of parathyroid adenoma
- Surgical excision
- Medical: K-Phos and/or Neutra-Phos
Dx of parathyroid adenoma
increased PTH d/t increased Ca++ and decreased PO–3
Parathyroid adenoma epidemiology
-~ 85% are single adenomas & benign
-< 1% are malignant
-Familial versions
-Multiple Endocrine Neoplasia (MEN) of various types
(Red flags if any GI cancers present in family history: pancreatic, stomach, etc.)
Diagnostic tests for parathyroid adenoma
- U/S of occasional benefit
- 10% are ectopic
- Scintiscans: thallium-201 for parathyroids (uptake in thyroid & parathyroid); 99mTc sestamibi/CT scan pre-op
- digital subtraction technology
- may be “embedded” in thyroid
- “transplant” to SCM MM or forearm former surg. tx
- PTH assay intra-operatively
Describe normal adrenals on CT
- Bilobed
- Surrounded by fat - aid to identification
- R: above upper pole R kidney
- L: anterior to upper pole L kidney
Adrenals
-functioning tumors
Diagnosed clinically
- Cushing’s
- Addison’s
- Pheochromocytoma
-Abnormal serum or urine studies
What are the benefits of CT for adrenals?
- Best for routine evaluation
- Consistently shows size/shape
What are the benefits of U/S & MRI for adrenals?
- U/S used initially
- Displays retroperitoneum
- Shows relationship of mass to adjacent organs: when origin of mass in question (renal vs. adrenal origin)
Describe adrenal tumors
- Generally > 2 cm.
- CT delineates tumor well
- MRI an option
- 10% are bilateral
Aldosterone in the adrenals
-Production in outer zone of gland
Mineralocorticoid:
- Na + resorbed
- K + excreted
Describe Conn’s tumor
- unilateral adrenal aldosteronoma
- < 1 cm
- can be difficult to “image” with CT scan
Cortisol in the adrenals
- Produced in inner zone
- Counters insulin effect
- Modulates inflammation
Primary adrenal INsufficiency
-Acute
- Acute –> Adrenal Crisis
- S/P surgery or stress
- decreased Na+ & Glc.; increased K+; decreased BP
- Tx: IV hydrocortisone
Primary adrenal INsufficiency
-Chronic
- Addison’s disease*
- decreased Na+ and increased K+; decreased BP
- increased Pigment; Weakness
- Non-responsive to Cosyntropin (~Artificial ACTH)
Adrenals
-Cortisol overproduction
increased ACTH –> increased Cortisol –> Cushing’s
- No response to dexamethasone suppression test
- 90% Pituitary
- 10% Adrenal Hyperplasia
- Central obesity; muscle wasting
- increased Glc; decreased K+
- Bruising and Striae
- Dorsal Fat Pad
What is the best diagnostic method for pheochromocytoma?
-CT vs. MRI
- *CT – best for routine evaluation
- Consistently shows size/shape
MRI:
- Displays retroperitoneum in any plane
- Shows relationship to adjacent organs –> benefit if origin in question (renal vs. adrenal)
Describe diagnosis of adrenal tumors that are > 2cm
- CT delineates tumor well
- MRI an option
- 10% are bilateral
Sx of pheochromocytoma
- HA, diaphoresis, nausea, wt. loss, heat intolerance (sounds like HYPERthyroidism)
- C-V – palpitations, HTN
- Ψ – anxiety, tremor
- TSH & T4 normal
What is MIBG in adrenal metastasis?
MIBG = meta-iodo-benzyl guanidine
- –Concentrated in pheochromocytomas
- –Delineates mets or multiple tumors
