Retroperitoneum

Retroperitoneum

Addison disease

life-threatening condition caused by partial or complete failure of the adrenocortical function. Also known as adrenocortical insufficiency.

adrenogenital syndrome

congenital disorder causing an increase in production of androgens.

uncommon condition resulting from excessive aldosterone secretions.

Cushing syndrome

a metabolic disorder resulting from chronic and excessive production of cortisol by the adrenal cortex. Results in the inability of the body to regulate secretions of cortisol or adrenocorticotrophic hormone (ACTH). Also known as hyperadrenalism.

diaphragmatic crura

fibers that connect the vertebral column and diaphragm. They are identified superior to the celiac axis and lie anterior to the aorta and posterior to the inferior vena cava.

enlarged lymph nodes posterior to the aorta giving the impression that the aorta is floating above the spine.

hyperaldosteronism

excessive production of aldosterone.

lymphadenopathy

focal or generalized enlargement of the lymph nodes.

malignant tumor of the adrenal gland found in young children.

pheochromocytoma

rare vascular tumor of the adrenal medulla.

retroperitoneal

pertaining to organs closely attached to the posterior abdominal wall.

retroperitoneal fibrosis

dense fibrous tissue proliferation typically confined to the paravertebral and central retroperitoneum areas.

suprarenal glands

adrenal glands.

Physiology

Adrenal glands (fig. 12-1)

• A pair of endocrine glands located in the retroperitoneum.

Function of the adrenal glands

• Produce hormones.

Epinephrine (adrenaline)

• Secreted by the medulla.

• Increases in times of excitement or emotional stress.

Norepinephrine

• Secreted by the medulla.

• Acts to increase blood pressure by vasoconstriction without affecting cardiac output.

Glucocorticoids

• Normal range:

• 4 to 22 μg/dL (morning)

• 3 to 17 μg/dL (afternoon)

• 20 to 90 μg/dL

• Secreted by the cortex.

• Aids in the body’s response to stress.

• Modifies the body’s response to infection, surgery, or trauma.

• Aids in controlling the amount of water in the body.

• Controls protein and carbohydrate metabolism.

• Increases with stress and decreases with inflammation.

Gonadal hormones

• Androgens, estrogens, and progesterone.

• Secreted by the cortex.

Mineral corticoids

• Aldosterone.

• Secreted by the cortex.

• Helps maintain the body’s fluid and electrolyte balance by promoting sodium reabsorption and potassium excretion within the kidneys.

Anatomy

• Consists of two regions.

• Medulla—inner portion, which comprises 10% of the gland.

• Cortex—outer portion, which comprises 90% of the gland.

Location

• Retroperitoneal structures located in Gerota’s fascia within the perinephric space.

• Located anterior, medial, and superior to each kidney.

• Lie lateral to the diaphragmatic crura.

• Right adrenal gland lies posterior and lateral to the inferior vena cava.

• Left adrenal gland lies lateral to the aorta and posterior-medial to the splenic artery and tail of the pancreas.

Size

• Adult adrenal gland measures 3 to 5 cm in length, 2 to 3 cm in width, and 1 cm in height.

Vascular anatomy

• The superior, middle, and inferior suprarenal arteries supply the adrenal glands.

• Superior suprarenal artery arises from the inferior phrenic artery.

• Middle suprarenal artery arises from the lateral aspect of the abdominal aorta.

• Inferior suprarenal artery arises from the renal artery.

• Right suprarenal vein drains directly into the inferior vena cava.

• Left suprarenal vein drains into the left renal vein.

Normal sonographic appearance

• Solid, hypoechoic, crescent-shaped structures surrounded by echogenic fat.

• Prominent in the neonate and children demonstrating a hypoechoic cortex and hyperechoic medulla.

• Difficult to visualize in the adult.

Technique

Preparation

• No preparation is necessary for a sonogram of the adrenal glands or retroperitoneum.

• Nothing by mouth (NPO) 6 to 8 hours before examination for adults, 6 hours for children, and 4 hours for infants to decrease intestinal interference.

Examination technique and image optimization

• Use the highest-frequency abdominal transducer possible to obtain optimal resolution for penetration depth.

• Place gain settings to display the normal liver parenchyma as a medium shade of gray with adjustments to reduce echoes within the vessels.

• Focal zone(s) at or below the place of interest.

• Sufficient imaging depth to visualize structures immediately posterior to the region of interest.

• Harmonic imaging or decreasing system compression (dynamic range) can be used to reduce artifactual echoes within anechoic structures.

• Spatial compounding can be used to improve visualization of structures posterior to a highly attenuating structure.

• Supine, oblique, and/or decubitus positions may be used.

• Sagittal or coronal and transverse planes are used to evaluate and document the adrenal glands using surrounding anatomical landmarks.

• Documentation and measurement of the length, height, and width.

• Color Doppler imaging, using a 60-degree angle or less, to evaluate each adrenal gland visualized.

• Evaluation and documentation of the retroperitoneum using a four- or nine-quadrant method.

• Length, height, and width of visible lymph nodes, including color Doppler imaging of the hilum.

• Documentation and measurement of any abnormality in two scanning planes with and without color Doppler should be included.

Indications for examination

• Hypertension.

• Abdominal distention.

• Severe anxiety.

• Tachycardia.

• Weight loss.

• Diabetes mellitus.

• Evaluate mass from previous medical imaging study (i.e., CT).

Laboratory values

Adrenocorticotrophic hormone (ACTH)

• Normal range: 10 to 80 pg/mL.

• Regulates cortisol production.

• Produced in the pituitary gland.

• Elevation associated with adrenal tumor, Cushing disease, and lung tumor.

Aldosterone

• Normal range:

• Recumbent 3 to 10 ng/dL

• Erect 5 to 30 ng/dL

• Steroid secreted by the cortex.

• Regulates sodium and water levels, which affects blood volume and pressure.

• Elevation associated with hyperaldosteronism.

• Decreases associated with hypoaldosteronism and Addison disease.

Potassium

• Normal range: serum 3.5 to 5.0 mEq/L.

• Essential to the normal function of every organ system.

• Maintains necessary concentration of nutrients inside and outside of the cell.

• Elevation associated with Addison disease.

• Decreases associated with Cushing disease and hyperaldosteronism.

Sodium

• Normal range: serum 135 to 145 mEq/L.

• Major component in determining blood volume.

• Decreases associated with Addison disease.

Benign Adrenal Pathology

PATHOLOGY	ETIOLOGY	CLINICAL FINDINGS	SONOGRAPHIC FINDINGS	DIFFERENTIAL CONSIDERATIONS
Adenoma	Benign cortical mass Functioning or nonfunctioning Risk Factors: Diabetes mellitus Obesity Hypertension Older population	Asymptomatic Elevated adrenal hormones	Hypoechoic, homogeneous mass Smooth wall margins May demonstrate necrosis or hemorrhage	Adrenal hyperplasia Adrenocortical carcinoma Renal or liver mass Adrenal hemorrhage
Adrenal cyst	Rare Unilateral	Asymptomatic Hypertension	Anechoic mass Well-defined wall margins Posterior acoustic enhancement Walls may calcify	Cyst of the liver, spleen, or kidney Hydronephrosis
Adrenal hemorrhage	Adrenal mass Hypoxia Traumatic delivery Septicemia	Asymptomatic Palpable abdominal mass Decrease in hematocrit	Cystic or complex adrenal mass Frequently located on the right	Cyst or neoplasm of the liver, spleen, or kidney Adenoma Adrenocortical carcinoma
Adrenal hyperplasia	Proliferation in adrenal cells Typically bilateral	Asymptomatic Hypertension Elevated adrenocorticotrophic hormone (ACTH) level	Enlargement of the adrenal gland(s) Change in the normal triangular shape	Adenoma Adrenocortical carcinoma
Pheochromocytoma	Rare vascular tumor of the medulla Small percentage are malignant Right-side prevalence	Hypertension Sweating Tachycardia Chest or epigastric pain Headache Palpitations Severe anxiety Increase in epinephrine and norepinephrine	Solid mass Homogeneous texture May appear complex because of necrosis or hemorrhage May calcify Metastasis to liver, lymph nodes, lung, and bone if malignant	Renal mass Adrenocortical carcinoma Adrenal adenoma Adrenal hemorrhage

Malignant Adrenal Pathology

PATHOLOGY	ETIOLOGY	CLINICAL FINDINGS	SONOGRAPHIC FINDINGS	DIFFERENTIAL CONSIDERATIONS
Adrenocortical carcinoma	Neoplasm of the adrenal cortex Functioning or nonfunctioning	Hypertension Weakness Abdominal pain Weight loss Weakening of the bones	Complex or echogenic mass Irregular wall margins Tends to invade the IVC Metastasis to the lungs and bone	Renal mass Adrenal hemorrhage Pheochromocytoma Metastases
Metastases	Lung most common Breast Stomach	Hypertension Abdominal pain	Focal mass Variable in appearance	Renal mass Adrenal hemorrhage Pheochromocytoma Adrenocortical carcinoma
Neuroblastoma Third most common malignancy in infancy	Neoplasm of the adrenal gland common in young children Male prevalence Half occur before 2 years of age More common on the left	Palpable mass Abdominal distention Sweating Weight loss Fatigue Tachycardia	Heterogeneous mass Poorly defined wall margins Pinpoint calcifications (30%) Lymphadenopathy Mass encases the aorta, inferior vena cava, superior mesenteric artery, and vein No invasion of the renal vein Metastasis to the liver, bone, lung, and lymph nodes	Nephroblastoma Lymphoma Adrenal hemorrhage

Conditions Associated with the Adrenal Glands

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Tags: Abdomen, Obstetrics and Gynecolo, Sonography Exam Review Physics

Jun 15, 2016 | Posted by admin in GYNECOLOGY | Comments Off

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CONDITION	DESCRIPTION	ETIOLOGY	CLINICAL FINDINGS
Addison disease	Life-threatening condition caused by partial or complete failure of adrenocortical function (hypofunction) Destruction of the adrenal cortex Loss of cortisol and aldosterone secretions Increased incidence in females Diagnosis is established if the amount of cortisol in the plasma and steroid in the urine do not increase after stimulation with adrenocorticotrophic hormone (ACTH)