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Premium member Presentation Transcript Radiology and Endocrinology : Radiology and Endocrinology ANATOMY Radiography Ultrasound CT MRI FUNCTION Radionuclide Imaging - Scintigraphy - PET Radionuclide Imaging : 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 : 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 : Ideal radiopharmaceutical cheap and readily available radionuclide easily incorporated without altering biological behaviour radiopharmaceutical easy to prepare localises only in organ of interest t1/2 of elimination from body similar to duration of test Thyroid - radiography : Thyroid - radiography Little role Thyroid mass diagnosed incidentally on chest radiograph Thoracic inlet views may demonstrate tracheal compression Thyroid - ultrasound : 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 : 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 : Thyroid - scintigraphy 99m PERTECHNETATE Trapped but not organified Competes with iodide for uptake Cheap and readily available IODINE (123I or 131 I) Trapped and organified Better for retrosternal goitres Expensive, cyclotron generated RECENT (10 days) IODINE CONTRAST BLOCKS UPTAKE Thyroid scintigraphy : 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 : 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 : 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 : RNI in thyroid disease Investigation of hyperthyroidism Location of ectopic thyroid tissue (congenital hypothyroidism, retrosternal goitre) Little role in thyroid nodules 1ry Hyperparathyroidism : 1ry Hyperparathyroidism Type % Adenomas Single 80 Hyperplasia Chief cell 15 Clear cell 1 Carcinoma 4 RN parathyroid imaging : RN parathyroid imaging 99mTc / 201Tl 99mTc-MIBI subtraction scans early/late scans False positives: thyroid pathology False negatives: parathyroid hyperplasia Both good for ectopic parathyroids Parathyroid imaging : Parathyroid imaging US not good at finding ectopic glands CT Contrast Surgical artifacts MRI Good for localisation and ectopic glands Imaging parathyroids : Imaging parathyroids Uncomplicated 1ry 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 : Adrenal glands Cortex aldosterone cortisol adrenal androgens Medulla adrenalin Adrenal glands : 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 : 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 : 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 : 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 : 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 : 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 : Adrenal medullary RNI Phaeochromocytoma Paraganglioma Neuroblastoma Ganglioneuroblastoma Ganglioneuroma Adrenal medullary RNI : 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 : MIBG phaeochromocytomas (95% sensitivity) neuroblastoma (80 - 90% sens) carcinoid medullary thyroid carcinoma (MEN syndromes) Phaeochromocytomas : Phaeochromocytomas 10% malignant bilateral extra- adrenal paediatric Phaeochromocytomas : Phaeochromocytomas Diagnosis - biochemistry Localisation CT if > 2cm RNI to exclude - small tumours - bilateral adrenal - multifocal - metastases ‘Incidentalomas’ : ‘Incidentalomas’ Incidental adrenal mass in patients undergoing abdominal imaging (2%) Q. Is it functioning? Is it benign or malignant? Functioning ‘incidentalomas’ : Functioning ‘incidentalomas’ Diagnosis Clinical features Biochmistry Confirmation RNI Non-functioning : Non-functioning Non-functioning adenoma vs. metastasis CT using attenuation values MRI - chemical shift imaging Radiology and Endocrinology : Radiology and Endocrinology Localisation not Diagnosis IMAGING and theENDOCRINE SYSTEM : IMAGING and theENDOCRINE SYSTEM You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
Endocrine_Imaging as003 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 286 Category: Science & Tech.. License: All Rights Reserved Like it (1) Dislike it (0) Added: May 26, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Radiology and Endocrinology : Radiology and Endocrinology ANATOMY Radiography Ultrasound CT MRI FUNCTION Radionuclide Imaging - Scintigraphy - PET Radionuclide Imaging : 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 : 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 : Ideal radiopharmaceutical cheap and readily available radionuclide easily incorporated without altering biological behaviour radiopharmaceutical easy to prepare localises only in organ of interest t1/2 of elimination from body similar to duration of test Thyroid - radiography : Thyroid - radiography Little role Thyroid mass diagnosed incidentally on chest radiograph Thoracic inlet views may demonstrate tracheal compression Thyroid - ultrasound : 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 : 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 : Thyroid - scintigraphy 99m PERTECHNETATE Trapped but not organified Competes with iodide for uptake Cheap and readily available IODINE (123I or 131 I) Trapped and organified Better for retrosternal goitres Expensive, cyclotron generated RECENT (10 days) IODINE CONTRAST BLOCKS UPTAKE Thyroid scintigraphy : 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 : 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 : 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 : RNI in thyroid disease Investigation of hyperthyroidism Location of ectopic thyroid tissue (congenital hypothyroidism, retrosternal goitre) Little role in thyroid nodules 1ry Hyperparathyroidism : 1ry Hyperparathyroidism Type % Adenomas Single 80 Hyperplasia Chief cell 15 Clear cell 1 Carcinoma 4 RN parathyroid imaging : RN parathyroid imaging 99mTc / 201Tl 99mTc-MIBI subtraction scans early/late scans False positives: thyroid pathology False negatives: parathyroid hyperplasia Both good for ectopic parathyroids Parathyroid imaging : Parathyroid imaging US not good at finding ectopic glands CT Contrast Surgical artifacts MRI Good for localisation and ectopic glands Imaging parathyroids : Imaging parathyroids Uncomplicated 1ry 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 : Adrenal glands Cortex aldosterone cortisol adrenal androgens Medulla adrenalin Adrenal glands : 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 : 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 : 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 : 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 : 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 : 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 : Adrenal medullary RNI Phaeochromocytoma Paraganglioma Neuroblastoma Ganglioneuroblastoma Ganglioneuroma Adrenal medullary RNI : 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 : MIBG phaeochromocytomas (95% sensitivity) neuroblastoma (80 - 90% sens) carcinoid medullary thyroid carcinoma (MEN syndromes) Phaeochromocytomas : Phaeochromocytomas 10% malignant bilateral extra- adrenal paediatric Phaeochromocytomas : Phaeochromocytomas Diagnosis - biochemistry Localisation CT if > 2cm RNI to exclude - small tumours - bilateral adrenal - multifocal - metastases ‘Incidentalomas’ : ‘Incidentalomas’ Incidental adrenal mass in patients undergoing abdominal imaging (2%) Q. Is it functioning? Is it benign or malignant? Functioning ‘incidentalomas’ : Functioning ‘incidentalomas’ Diagnosis Clinical features Biochmistry Confirmation RNI Non-functioning : Non-functioning Non-functioning adenoma vs. metastasis CT using attenuation values MRI - chemical shift imaging Radiology and Endocrinology : Radiology and Endocrinology Localisation not Diagnosis IMAGING and theENDOCRINE SYSTEM : IMAGING and theENDOCRINE SYSTEM