*Imaging Flashcards
What type of tests are imaging tests?
X-rays (plain radiography, contrast studies e.g. braium enema, IVU, arthrography, CT)
US
MRI
Nuclear medicine
What is used in tayside to store and view digital imaging?
PACS (picture archiving and communications system)
To be seen on an x-ray, what must the pathology be in comparison to the surrounding?
A different density
How is a double contrast image created?
Barium is first put in to line mucosa and then emptied before squeezing in air - makes soft tissue more visible
What is IVU?
X-ray of the urinary tract after an IV injection of iodine
What is arthrogram?
Series of pictures of a joint after a contrast material e.g. iodine has been injected directly into it
What type of scanner tends to be used more often in a paediatric hospital?
Why?
An MRI scanner
X-rays are radiation and can therefore lead to cancerous mutations - as children have a high rate of new cell formation they have the highest risk of tumour formation
What material is used to stop x-rays?
Lead
Why are CT scans better than plain x-rays?
They fire x-rays from all round the body and process them on a computer to form a set of cross-sectional pictures with no superimposition - it has superior contrast resolution compared to a radiograph
Why don’t we just use CT for everything? (3)
Gives a large dose of ionising radiation
Soft tissues of very similar density cannot be distinguished e.g. pelvic organs, muscles and tendons, etc.
CT cannot resolve bone marrow disease
Do US or MRI use ionising radiation?
No
How does US work?
The transducer transmits sound pulses which reflect off objects returning at different times due to distant travelled
An image can then be built up on a computer due to this information
Main imaging for chest/ abdo/ pelvis imaging
What is US especially food for imaging?(5)
MSK soft tissue structures (tendons and muscles)
Gallstones in the gallbladder
Tumours of the bladder
Abnormal fluid collections e.g. pleural effusion, ascites, abscess, cysts
Soft tissue tumours
What are the weaknesses of US?
Bone blocks US (can’t see the brain, spinal canal, inside joint or assess bone marrow)
Gas blocks US so windy patients are difficult assess and gas containing structures like the lungs or bowel
Very fat patients
What does an MRI scanner use to produce the images?
A strong magnetic field created from electrical current passed through coiled metal wire surrounding the bore
Uses this to energise the body’s protons
What must patents remove before entering the MRI machine/
Any ferrous metal e.g. dental plates, ear rings, belts
Can surgical ferrous material e.g. pacemakers, heart valves and missile injuries
What must a patient fill in before having an MRI?
A card safety questionnaire
What must staff do before entering the MRI room?
Wear the appropriate safety equipment e.g. vest
Remove all possible metal items e.g. watch, keys, credit cards, etc.
MRI strengths? (6)
Most complete image of the brain possible
Can accurately assess pelvic organs
Can assess bone marrow abnormality in the absence of bone destruction
Sensitive way to assess acute muscle and tendon tears
Excellent imaging of spinal canal disease
Can image the interior of joint so injuries to cartilage and ligaments can be seen
Weaknesses of MRI?
Expensive can harm some patients claustrophobic take a long time Shows little detail of the lungs
Where do the bronchial arteries branch from?
How many do you have?
The aorta
1 right and 2 left bronchial arteries
How many pulmonary arteries are there?
How many pulmonary veins are there?
2 pulmonary arteries (right and left)
4 pulmonary veins (2 right and 2 left - upper and lower)
What are the 3 parts of the thoracic aorta?
Ascending
Arch
Descending
How many cusps does the aortic valve have?
3
What does the branches from the aortic arch supply?
The head, neck and arms
Where does the descending aorta pass into the abdomen
Through the aortic hiatus
Where does the descending aorta lie in relation to the oesophagus and spine
Posterior to the oesophagus but anterior to spine
What are the sequential branches of the subclavian artery?
Subclavian artery
Axillary artery
Brachial artery
Radial artery (laterial) and ulner artery (medial)
What is another name for the lung roots?
Hilum
At what level does the abdominal aorta bifurcate into 2 common iliac arteries?
L4
What are the 3 paired anterolateral branches of the abdominal aorta?
Rneal
Adrenal
Gonadal
What areas are at risk of receiving insufficient oxygen or nutrients with consequent tissue death?
Areas at a boundary between arterial territories (especially true in the elderly)
what is contained within the lung root/ hilum?
1 main pulmonary artery 2 pulmonary veins Bronchial arteries Lymphatics Nerves (On sagittal imaging, the artery is on the top with 2 veins below)
What is the name of the common origin of the middle and lower lobe bronchus?
Bronchus intermedius
Where does the oesophagus lie in relation to the trachea and great vessels at the thoracic inlet
Posterior to trachea and great vessels
indented by aortic arch
What does the oesophagus descend adjacent to?
The aorta and posterior to the left main bronchus
What part of the heart indents the oesophagus
The left atrium (passes posterior to the heart)
What segment of the liver does the gall bladder lie inferior to?
Segment 5
Where is the ampulla of vater located in relation to the duodenum?
On the medial wall of the 2nd part
What are the folds called which increase the surface area of the stomach?
Rugae
What side of the aorta does the mesentery of jejunum and the mesentery of ileum attach to?
Mesentery of jejunum = left of aorta
mesentery of ileum = right
Which kidney lies higher?
Left kidney
What are the 4 parts of the urethra in males?
Penile urterha
Bulbous urethrea
Membranous urethra
Prostatic urethra
Where is the prostate located in relation to the urethra and bladder
Prostate is at the base of the bladder and surrounds the urethra
