Anatomy of Adrenal Gland :1 Anatomy of Adrenal Gland By Dr Sohail Amin Resident-1


Introduction :2 Introduction Among most important and vital endocrine organ Small bilateral yellowish retroperitoneal organ Lies just above kidney in gerota’s fascia


Anatomy :3 Anatomy Right adrenal is triangular, related to upper pole Right kidney Left adrenal is crescent shaped, related to upper and medial part Left kidney Size : 3 - 6cm long, 0.9 – 3.6cm Weight : 3-5 gm app Width : 2-3 cm


Anatomy :4 Anatomy


Embryology :5 Cortex is mesodermal in origin Week 4 – 6 : start from coelomic mesoderm adjacent to urogenital ridge Week 8 : differentiate into thin definite outer cortex and thick inner fetal cortex Embryology


Cont: :6 Cont: Fetal cortex produce steroid during gestation and involutes at birth Definite cortex develop into functional adrenal cortex


Embryology :7 Embryology Medulla derived from neural crest cells Develop with sympathetic nervous system Week 5 : neural crest cell migrate to Para-aortic and Para-vertebral region towards medial aspect of adrenal cortex


Cont: :8 Cont: Extra adrenal chromaffin cells located to the left of aortic bifurcation near the origin of IMA


Embryology :9 Embryology


Embryology :10 Embryology


Embryology :11 Embryology


Embryology :12 Embryology


Histology :13 Histology Adrenal cortex consists of three distinct zones Zona Glomerulosa : small cells with intermediate no. of lipid inclusion Zona Fasiculata : large foamy cells sec to lipid inclusion -75% of cortex


Cont : :14 Cont : Zona Reticularis : consists of compact cytoplasm and few lipid inclusions Zona glomerulosa and fasiculata present at birth Zona reticularis develops during first year of life


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Histology :16 Histology


Physiology :17 Physiology Adrenal gland has two distinct zones Adrenal cortex Adrenal medulla


Physiology :18 Physiology Adrenal cortex produces -Glucocorticoids (Zona Fasciculata) -Mineralocorticoids (Zona Glomerulosa) -Adrenal androgens (Zona Reticularis)


Physiology :19 Physiology Adrenal medulla produces -Epinephrine (adrenaline) -Norepinehrine (noradrenaline) Help inc in cardiac output, vascular resistance and mediate stress response All are absolutely required for life


Functions :20 Functions Aldosterone helps in Na reabsorption & potassium excretion & preventing dehydration Cortisol stimulate protein breakdown, inhibition of tissue response in injury & antagonism to action of insulin Androgens helps in early development of male sex organ in childhood


Functions :21 Functions


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Relations :23 Relations RT ADRENAL Anteriorly IVC Liver Posteriorly Diaphragm LT ADRENAL Anteriorly Pancreas Stomach Posteriorly Diaphragm


Relations :24 Relations


Vascular supply :25 Vascular supply Blood to adrenal supplied by Inferior phrenic artery (superiorly) Aorta (medially) Renal artery (inferiorly) Rt adrenal : superior & inferior adrenal artery Lt adrenal : middle & inferior adrenal artery


Vascular supply :26 Vascular supply Right Adrenal : drained to IVC via adrenal vein Left Adrenal : drained into left adrenal vein or directly to IVC Lymphatics : drained to Para-aortic and para-caval lymph nodes


Vascular supply :27 Vascular supply


Vascular supply :28 Vascular supply


Imaging Modalities :29 Imaging Modalities Plain abdominal film Ultrasound (grey scale and Doppler) Adrenal venography Adrenal arteriography CT scan MRI Adrenal scintigraphy


Plain Abdominal Film :30 Plain Abdominal Film Plain abdominal film finding are non specific May be helpful in detecting Mass in adrenal area Calcification in adrenal


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Ultrasound :32 Ultrasound Adult appearance Entirely hypoechoic Concave with straight margin Newborn Cortex hypoechoic, Medulla hyperechoic Cortex>>medulla thickness Convex border


Ultrasound :33 Ultrasound Investigation of first choice in infant , children and pregnant women Indication adrenal masses ( larger than 2 cm)


Ultrasound :34 Ultrasound


Ultrasound :35 Ultrasound


Ultrasound :36 Ultrasound


CT Scan :37 CT Scan On precontrast scan adrenal have soft tissue density similar to that of liver Normal adrenal appear inverted V or Y shape within retroperitoneal fat Consist of body , medial limb and lateral limb


Ct Scan :38 Ct Scan Thickness of each limb is 5 mm Maximum width of the body is 10-12mm Indication masses (adenoma & cancer) Cyst abscess metastasis


CT Scan :39 CT Scan


CT Scan :40 CT Scan


CT Scan :41 CT Scan Attenuation is measured in Hounsfield unit (HU) Benign masses have low attenuation values ( 20 HU )


CT Scan :42 CT Scan Unenhanced CT Scan Adenomas : 20 HU Delayed enhanced CT Scan Adenoma : 30 HU


Adrenal Adenoma :43 Adrenal Adenoma


Adrenal Adenoma :44 Adrenal Adenoma


Adrenal Carcinoma :45 Adrenal Carcinoma


MRI :46 MRI Equally effective as CT in imaging adrenal disorder Normal adrenal is intermediate signal intensity to liver and hypo intense to fat on TIW1 image On T2W2 image adrenal hypo intense to fat, iso intense to liver &hyper intense to crus


MRI :47 MRI Carcinoma have hyper-intense signal on T2W2 and hypointense on T1W1 images On contrast enhancement show rapid enhancement with sluggish washout Adenoma are hypointense, show mild enhancement & rapid contrast washout


Adrenal On MRI :48 Adrenal On MRI


Normal Adrenal On MRI :49 Normal Adrenal On MRI


Adrenal Venography :50 Adrenal Venography Selective injection of contrast into the adrenal vein with an angiographic catheter Indication For localization of hormone active tumor For adrenal hyperplasia & adrenal adenoma Cushing’s diseases


Adrenal Venography :51 Adrenal Venography Classic gland like pattern of intraglandular rt adrenal vein


Adrenal Venography :52 Adrenal Venography Showing rounded configuration of adenoma in lateral limb


Adrenal Venography :53 Adrenal Venography Shows extensive destruction of venous structure


Adrenal Arteriography :54 Adrenal Arteriography Procedure in which contrast is injected into adrenal arteries to detect any vascular pathology Indication Adrenal tumor Adrenal hyperplasia CONN syndrome


Adrenal scintigraphy :55 Adrenal scintigraphy Usual role of scintigraphy is to clarify inconclusive result of imaging Indication Functional status of adrenal nodule Assess contralateral adrenal function Detect functional metastasis Detect recurrence after surgery Detect ectopic site of hormone production


Adrenal Scintigraphy :56 Adrenal Scintigraphy Adrenocortical imaging agent NP-59 ( 6-B-iodomethyl-19-norcholesterol ) Selenium-75 6-B-selenomethylnorcholesterol Sympathoadrenal imaging agent MIBG ( metaiodobenzylguanidine )


Adrenal Scintigraphy :57 Adrenal Scintigraphy Indication for MIBG Pheochromocytoma Neuroblastoma, carcinoid, adrenal metastasis Indication for NP-59 Adrenocortical carcinoma Adenoma Adrenal hyperplasia


MIBG Scintigraphy :58 MIBG Scintigraphy MIBG Scintigraphy: high uptake in LT adrenal ,Pheochromocytoma


MIBG Scintigraphy :59 MIBG Scintigraphy MIBG : Inc tracer accumulation in lt adrenal mass


THANK YOU :60 THANK YOU