• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Radiology and Endocrinology
 

Radiology and Endocrinology

on

  • 2,460 views

 

Statistics

Views

Total Views
2,460
Views on SlideShare
2,309
Embed Views
151

Actions

Likes
0
Downloads
48
Comments
0

1 Embed 151

http://www.webicina.com 151

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Radiology and Endocrinology Radiology and Endocrinology Presentation Transcript

    • Radiology and Endocrinology
      • ANATOMY
      • Radiography
      • Ultrasound
      • CT
      • MRI
      • FUNCTION
      • Radionuclide Imaging
      • - Scintigraphy
      • - PET
    • Radionuclide Imaging
      • Images metabolic pathways
      • Pharmaceutical which mimics a component of a normal metabolic pathway is administered to the patient
      • Pharmaceutical radiolabelled so that its distribution in the patient can be visualised with a gamma camera
    • Ideal Radionuclide
      • emits gamma radiation at suitable energy for detection with a gamma camera
      • (60 - 400 kev, ideal 150 kev)
      • should not emit alpha or beta radiation
      • half life similar to length of test
      • cheap
      • readily available
    • Ideal radiopharmaceutical
      • cheap and readily available
      • radionuclide easily incorporated without altering biological behaviour
      • radiopharmaceutical easy to prepare
      • localises only in organ of interest
      • t 1/2 of elimination from body similar to duration of test
    • Thyroid - radiography
      • Little role
      • Thyroid mass diagnosed incidentally on chest radiograph
      • Thoracic inlet views may demonstrate tracheal compression
    • Thyroid - ultrasound
      • High resolution (5 - 10 MHz)
      • Confirms - mass is thyroid
      • cystic or solid
      • single or multiple
      • cannot distinguish solid carcinoma from solid dominant nodule
      • Not useful in hyperthyroidism
    • Thyroid - CT/MRI
      • Not as good as US at resolving lesions within the thyroid
      • Best tests for assessing mediastinal disease
      • CT better than MRI for calcification
      • MRI better than CT for distinguishing between fibrosis and residual tumour
    • Thyroid - scintigraphy
      • 99m PERTECHNETATE
      • Trapped but not organified
      • Competes with iodide for uptake
      • Cheap and readily available
      • IODINE ( 123 I or 131 I)
      • Trapped and organified
      • Better for retrosternal goitres
      • Expensive, cyclotron generated
      • RECENT (10 days) IODINE CONTRAST BLOCKS UPTAKE
    • Thyroid scintigraphy
      • 99m Tc 123 NaI
      • ADMIN iv po/iv
      • PATIENT withdraw thyroid Rx
      • PREP avoid high Iodine foods
      • IMAGING 15 min pi 1-2hr pi
      • 24 hr po
    • Hyperthyroidism
      • RN uptake
      • 1. Thyroid gland (>95%)
      • Toxic nodular goitre
      • Diffuse toxic goitre (Graves)
      • Thyroiditis
      • 2. Exogenous T3/4/iodine
      • Iatrogenic
      • Iodine - induced
      • (XRay contrast, amiodarone)
    • Thyroid nodules
      • Risk of malignancy
      • Overall 10%
      • US - cystic 0.3 - 10%
      • US - solid ????
      • RNI - cold 16%
      • RNI - hot 4%
      • First line investigation: Cytology +/- US
    • RNI in thyroid disease
      • Investigation of hyperthyroidism
      • Location of ectopic thyroid tissue (congenital hypothyroidism, retrosternal goitre)
      • Little role in thyroid nodules
    • 1 ry Hyperparathyroidism
      • Type %
      • Adenomas Single 80
      • Hyperplasia Chief cell 15
      • Clear cell 1
      • Carcinoma 4
    • RN parathyroid imaging
      • 99m Tc / 201 Tl 99m Tc-MIBI
      • subtraction scans early/late scans
      • False positives: thyroid pathology
      • False negatives: parathyroid hyperplasia
      • Both good for ectopic parathyroids
    • Parathyroid imaging
      • US not good at finding ectopic glands
      • CT Contrast
      • Surgical artifacts
      • MRI Good for localisation and ectopic glands
    • Imaging parathyroids
      • Uncomplicated 1 ry hyperparathyroidsim
      • 90 -95% surgical success rate without imaging
      • Recurrent/persistent hyperparathyroidism
      • surgical success rate without imaging -50%
      • with imaging - 90%
      • (combined RNI + MRI)
    • Adrenal glands
      • Cortex aldosterone
      • cortisol
      • adrenal androgens
      • Medulla adrenalin
    • Adrenal glands
      • AXR - may show calcification
      • US - large masses only (unless neonatal)
      • CT - can detect small lesions
      • - cannot distinguish metastases from non-functioning adenomas
      • MRI - small lesions
      • - may distinguish mets from
      • non-functioning adenomas
    • Adrenal cortical RNI
      • Radiolabelled cholesterol esters
      • ( 75 Seleno-methylnorcholesterol,
      • 131 I - 6B iodomethyl-19-norcholesterol)
      • Image at 4 and 7 days
      • > 50% difference in activity between sides is abnormal
    • RNI in Cushings syndrome
      • ACTH-dependent CS bilat
      • pituitary/ectopic
      • ACTH -independent CS
      • bilat nodular hyperplasia bilat
      • adrenocortical adenoma uni
      • Adrenocortical carcinoma bilat
    • Cushings syndrome
      • Diagnosis - biochemistry
      • Localisation - CT/MRI
      • for
      • 1. Pituitary ACTH-dependent
      • 2. Ectopic ACTH-dependant
      • 3. ACTH - independant
      • RNI not usually necessary
    • RNI and Cushings syndrome
      • Used for
      • 1. Finding residual functioning adrenal remnants if recurrent disease after prior bilateral adrenalectomy
      • 2. Somatostatin receptor scanning for ectopic ACTH from small bronchial carcinoid tumours
    • Primary aldosteronism
      • small tumours may not be seen with CT/MRI
      • RNI + dexamethasone suppression can find tumours < 1cm
      • Adrenal visualisation before 5 days is abnormal (bilateral/unilateral)
    • Adrenal medullary RNI
      • Phaeochromocytoma
      • Paraganglioma
      • Neuroblastoma
      • Ganglioneuroblastoma
      • Ganglioneuroma
    • Adrenal medullary RNI
      • Metaiodobenzylguanidine (MIBG)
      • - localises in catecholamine storage vesicles of adrenergic nerve endings
      • - 123 I or 131 I
      • somatostatin receptor imaging
      • 111 In octreotide
    • MIBG
      • phaeochromocytomas (95% sensitivity)
      • neuroblastoma (80 - 90% sens)
      • carcinoid
      • medullary thyroid carcinoma
      • (MEN syndromes)
    • Phaeochromocytomas
      • 10% malignant
      • bilateral
      • extra- adrenal
      • paediatric
    • Phaeochromocytomas
      • Diagnosis - biochemistry
      • Localisation
      • CT if > 2cm
      • RNI to exclude - small tumours
      • - bilateral adrenal
      • - multifocal
      • - metastases
    • ‘ Incidentalomas’
      • Incidental adrenal mass in patients undergoing abdominal imaging (2%)
      • Q. Is it functioning?
      • Is it benign or malignant?
    • Functioning ‘incidentalomas’
      • Diagnosis
      • Clinical features
      • Biochmistry
      • Confirmation
      • RNI
    • Non-functioning
      • Non-functioning adenoma vs. metastasis
      • CT using attenuation values
      • MRI - chemical shift imaging
    • Radiology and Endocrinology
      • Localisation
      • not
      • Diagnosis
    • IMAGING and the ENDOCRINE SYSTEM