Imaging relevant to endocrine disease Flashcards
Where does the pituitary gland sit?
In the base of the skull in the sella turcica of the sphenoid bone
Connected to hypothalamus via pituitary stalk
Found inferior to the optic chiasm
Lateral to the carotid arteries
What type of pituitary tumours tend to be hormonally active?
Microadenomas
What does the thyroid gland lie deep to?
Strap muscles: stenohyoid, sternothyroid, thyrohyoid, omohyoid
What are the anatomical landmarks of the thyroid gland?
Anterior to trachea and esophagus
Deep to strap muscles
Medial to common carotid and internal jugular veins
Lies superior to the sterum
Associated with recurrent laryngeal nerves and parathyroid gland
What structures do the left and right recurrent laryngeal nerves pass under respectively?
Right - Right subclavian artery
Left - arch of the aorta
What can present as a midline neck mass?
Goitre Lymph nodes but typically eccentric Thyroglossal cyst Cystic hygroma Thyroid cancer Metastatic cancer
When is a thyroid ultrasound used?
In euthyroid patients with a goitre/palpable nodules and hyperthyroid patients with a focal mass/ radioisotope uptake
What is used in thyroid scintigraphy?
Tc 99
What does a homogenous increased tracer uptake of more than 3% suggest?
Graves disease
What conditions will cause reduced uptake by the thyroid gland?
Hashimotos
Amiodarone disease
Post-partum thyroiditis
Where do the adrenal glands lie?
Suprarenal position
What are the anatomical relations of the right adrenal gland?
Posterior to the IVC
What are the anatomical relations of the left adrenal gland?
Lateral to the aorta and left diaphragmatic crus
What is the 10% rule of phaeochromocyomas?
10% are extra-adrenal 10% are bilateral 10% are found in children 10% are familial - MEN syndrome 10% are not associated with hypertension
What cancers should be looked for in the ase of an adrenal metastasis?
Lungs
Liver
Adrenal glands
How will long bones grow?
Start as cartilage and undergo enchondral ossification
Osteoblasts will replace the cartilage with osteoid to form bony trabeculae. Trabeculae are loosley packed in the medulla but condense towards the cortex
How will cartilagenous bones grow?
First ossify within the diaphysis
Secondarily they ossify within the epiphysis
How is increased bone girth achieved?
Cells derived from the periosteum which lay down circumferential new bone on the periphery of the existing cortex
How is increased bone length achieved?
Increased by cartilage proliferation at growth plates between the metaphysis and epiphysis
The cartilage will ossify
What is a diffuse bone abnormality?
All bones are too brittle
All bones are too soft
What can cause a focal bone abnormality?
Traumatic
Neoplastic (lytic or sclerotic)
Inflammatory
Degenrative
What can cause a diffuse bone abnormality?
Osteoporosis
RIckets and osteomalacia
Pagets disease
Fibrous dysplasia
What causes osteoporosis?
Reduction in trabecular density
Post-menopausal females
What are the typical fracture sites for osteoporotic bones?
Proximal femur - NOF
Sacrum and pubic rami
Thoracolumbar vertebral bodies
Distal radius - colles
What can cause secondary osteoporosis?
Steroids
Early menopause
Anorexia
Induces via cancer surgery
How can you distinguish between an osteoporotic fracture and metastatic disease?
Osteoporotic fractures will only affect the anterior vertebral bodies
Metastatic disease will involve posterior elements
What is rickets?
Vit D deficiency Non-ossification of soft osteoid Bone deformity, pain and growth abnormality Widened growth plates Irregular, flared metaphyses
What is pagets disease?
Increased bone turnover with unknown cause
Single or multiple bones affected
Initial lytic phase results in well definced lucency
Latter sclerotic phase with enlarged bones, increased density, coarse trabecular pattern
What is lytic bone destruction?
Medullary lucency and loss of trabeculae
Loss of inner cortex (endosteum(
Complete loss of cortex
Potential for pathological fracture
What is a sclerotic bone lesion?
Sublte medullary density and loss of trabeculae
Spreading zone of density which includes cortex
Featureless white bone
Expansion beyone normal bone limits, with cortical destruction and potential for pathological fracture
What can cause sclerotic bone lesions?
Prostate cancer in men
Breast cancer in women
