Lecture 2b - Superficial Structures

Functions of the thyroid

• Endocrine gland

• Produces hormones (calcitonin - calcium homeostasis)

• Controls metabolism

• Controlled by the hypothalamus and pituitary

What connects the 2 lobes of the thyroid

Isthmus

Why is colour doppler preferred for thyroid scans

• One of the most vascular organs of the body

• Colour Doppler provides more diagnostic information in thyroid diseases

What transducer is used for thyroid scans

High resolution linear array transducer (7.5-17.0 MHz)

Thyroid characteristics on an US

• Homogenous

• Slightly hyperechoic

• Butterfly shaped

Name this view

Transverse view of thyroid

Name this view

Longitudinal view of thyroid

How are thyroid volume measurements taken

Length of longitudinal view X width of lobe X depth of lobe

What’re the TI-RADS categories

• Composition

• Echogenicity

• Shape

• Margin

• Echogenic foci

Where are the parathyroid glands

Posterior medial surface of thyroid gland

Parathyroids are only seen when…

They contain pathology

What is goitre

• Swelling of the thyroid gland due to hyperplasia of normal tissue or thyroiditis

• May be symmetric, asymmetric or multinodular

What is a thyroid nodule

Discrete lesion in the thyroid that is distinct from the surrounding thyroid parenchyma

What is the pathology

Thyroid nodule

What is the pathology

Thyroid nodule

Name the pathology

Multinodular goitre

What is Hashimoto’s disease

• Diffuse glandular enlargement

• Autoimmune thyroiditis

How does Hasimoto’s diease appear on US

• Giraffe pattern

• More hypoechoic than normal thyroid tissue

• May have any degree of vascular flow

Name the pathology

Hashimoto’s thyroiditis

Name the pathology

Hashimoto’s thyroiditis

What is graves disease

• Diffuse abnormality

• Hyperfunctioning thyroid

• Abnormal immune response that attacks the thyroid and causes it to overproduce hormone thyroxine

What are the characteristics of graves disease on US

• Diffusely hypoechoic gland

• Heterogeneous

• Colour Doppler demonstrates hypervascularity (thyroid inferno)

What is this pathology

Graves disease

Name this pathology

• Graves disease

• Thyroid inferno

What does thyroid carcinoma look like on US

• Solid hypoechoic mass

• Irregular shaped

• Heterogeneous

• Microcalcifications with or without shadowing

• Hypervascularity

• Cervical lymph nose metastases

Name the pathology

Thyroid papillary carcinoma

How does a normal cervical lymph node appear on US

Cortex must be bigger than medulla

Name the pathology

Abnormal lymph node

What is a fine needle aspiration

• Used for sus nodules or neck masses

• US guided FNA allows for precise needle tip placement

What happens nodules that are >1cm

Biopsy

What happens to nodules that are <1cm

• Fine needle aspiration

• US to monitor progress

Layers of the breast

• Skin

• Subcutaneous layer

• Mammary layer

• Retromammary layer

• Pectoralis

What does the subcutaneous layer of breast contain

Fatty tissue divided by thin connective tissue

What does the mammary layer of the breast contain

• 15-20 lobes

• Divided by Cooper’s ligaments

• Each lobe opens to the surface of the nipple through a lactiferous duct

Describe Cooper’s ligaments

• Fibrous connective tissue in the mammary layer of the breast

• Extends from the deep layer to the superficial layer

• Echogenic (seen in fatty layer, hidden in glandular tissue)

What transducer is used for breast US exams

High resolution linear array transducer (7.5-17.0 MHz)

Patient positioning for breast examinations

• Patient supine oblique

• Shoulder and torso of the effected side elevated

• Arm above head

Scanning technique for breast imaging

• Transverse

• Longitudinal

• Radial

• Antiradial

What’re the US characteristics of each layer of breast normally

Skin: 2 thin hyperechoic layers

Subcutaneous layer: hypoechoic separated by hyperechoic Cooper’s ligaments

Mammary layer: Hyperechoic compared to fat, homogenous

Retromammary: Hypoechoic pattern

Pec: Striated appearance

What is this

Milk ducts

Describe the pathology

• Breast cyst

• Posterior enhancement

• Anechoic

• Solid circumscribes boarders

Describe the pathology

• Breast abscess

• Hypoechoic

• Heterogeneous

• Light posterior enhancement

What is fibroadenoma

Benign solid lesion of breast

Describe this pathology

• Fibroadenoma

• Small firm nodule

• Moves when palpated

• Round with defined boarders

• Hypoechoic with isoechoic fat lobules

What’re the characteristics of breast carcinoma

• Irregular borders

• Hypoechoic relative to fibroglandular/fatty tissue

• Posterior acoustic shadow

• E

Describe the pathology

• Breast carcinoma in glandular mammary layer

• Posterior enhancement

• Heterogenous

• Ill defined borders

• Hypoechoic

What is the pathology

Breast carcinoma

What is the pathology

• Breast carcinoma

• Flood flow = cancer

Testicular anatomy

• Scrotal wall

• Tunica vaginalis

• Tunica albuginea

Describe the function of the tunica vaginalis

Creates space that contains a small amount of fluid hat prevents friction between the scrotal structures

Describe the function of the tunica albuginea

• Composed of dense connective tissue

• Encases each testis and covered by he tunica vaginalis

What is an intratesticular lesion

Malignant testicle lesion

What is an extratesticular lesion

Benign testicular lesion

What is cryptorchidism

Incomplete or partial failure of the intra-abdominal testes to decent into the scrotal sac

What is the pathology

Cryptorchidism in the inguinal canal

What transducer is used for scrotal exams

High resolution linear array transducer (7.5-17.0 MHz)

What shape is the testis in longitudinal view

Oval

What shape is the testis in a transverse view

Circle

Label

What is the pathology

Cyst in epididymal head

Name the pathology

Testicular torsion

What is a hydrocele

Abnormal accumulation of serous fluid between the visceral and parietal layers of the tunica vaginalis

What is the pathology

Testicular hydrocele

What is the pathology

Testicular hydrocele

What is testicular varicocele

• Collection of abnormal dilated. tortuous and elongated veins of the pampiniform plexus located posterior to the testis

• Caused by incompetent valves in the testicular veins

What is the pathology

Epididymitis

What is the pathology

Epididymitis

What is the pathology

Seminoma (testicular carcinoma)

What is the pathology

Testicular rupture

What is the pathology

Testicular rupture

What is the pathology

Testicular fracture