Radiology Qs Flashcards
Water is whiter in T1 or T2? WWII
Fat is whiter in?
What is a fluoroscopy of uterus and fallopian tubes called?
Hysterosalpingography
In T1 MRI scans - what is the appearance of:
- CSF
- Grey matter
- White matter
- Fat / Blood / Contrast
CSF = low signal (black)
Grey matter = grey
White matter = white
Fat/Blood/Contrast = high signal = white
In T2 MRI Scans - what is the appearance of:
- CSF
- Grey matter
- White matter
- Pathology
- Water
T2
CSF = white
Grey matter = white
White matter = grey
Pathology = high signal (white)
Water = White (WW2)
What is a FLAIR scan?
T2 scan but the CSF signal is attenuated (removed) so it appears black.
Other things of a T2 scan look the same.
What type of MRI scans are best for stroke?
DWI - Diffusion Weighted Imaging
What MRI scan is best for blood?
Gradient Echo T2
What are the following radiological scores used for?
- MTA Score
- Fazekas Score
- Global Cortical Atrophy Score
What is the cutoff MTA score for a diagnosis of AD in Ps?
> 75 years = 3+
<75 years = 2+
Apart from AD - what are the DD for hippocampal atrophy?
How can you tell which DD it may be?
Frontotemporal dementia
Previous Infection
Paraneoplastic
AI
What causes idiopathic normal pressure hydrocephalus?
What do patients present with sx wise?
The cause of excess fluid in the ventricles of the brain may be due to injury, bleeding, infection, brain tumor, or surgery on the brain. However, the cause is often not known. When excess fluid builds up in the ventricles, they enlarge and press against nearby brain tissue.
Classically presents with clinical triad of dementia, gait
When is nuclear medicine used in neurocognitive disorders?
When MRI is not conclusive.
Which scan is indicated for detecting loss of functional dopaminergic neurons due to Parkinsons or parkinsonian syndromes?
DaTSCAN (is a type of SPECT scan)
What are the two key features of AD on PET scan?
Accumulation of extracellular amyloid β plaques
Intracellular neurofibrillary tau protein tangles
Which has better resolution? SPECT or PET
PET has better resolution than SPECT
Interpret
Very large left hemisphere infarct
Interpret
Lacunar infarct - left thalamus
Interpret
Deep haemorrhage LHS - classical of a hypertension haemorrhage
What types of MRI Imaging is seen here?
Top left = T2 (small lacunar infarct LHS)
Top right = T2 FLAIR (infarction appears white)
Bottom left = DWI - good for infarction - bright white for 10 days after
Bottom right = ADC - darker in acute infarction
Interpret this scan
Normal head CT - no asymmetry seen
Look for asymmetry
Low density areas
Blood
Interpret
Normal scan of older P - bit of shrinkage, bigger ventricles
Lots of atrophy
Big ventricles
Big sulk
Cerebral volume loss
Periventricular ischaemic change
Common findings in older Ps
Interpret
Severe ischaemic change
Atrophy of the brain - big sulci
Dark areas = greater loss of tissue
Extensive periventricular ischaemia
Interpret
Calcification of the basal ganglia - note the symmetry in appearance
Interpret
Could be a clot - or could be thickened vessel which looks whiter than normal - does the P have symptoms? Always diagnose in line with clinical features.
Interpret
Infarct developing on LHS of brain
Interpret
Massive infarct - LHS brain
Interpret
Infarct on RHS with haemorrhagic transformation
Interpret
Swelling complication of infarct which has pushed the midline across to the right.
Significant pressure can lead to brain herniation and will require a hemicraniectomy. Primarily a problem for younger Ps (less cranial space due to less brain shrinkage).
Interpret
Ischaemia in LHS due to infarct and infarct developing on RHS
Bilateral infarcts - left front and right central
Interpret
Left occipital infarct - posterior cerebral artery supplies
Interpret
Lacunar infarct in left thalamus
Interpret
Intracerebral haemorrhage - gone into the ventricle
Interpret
Big bleed LHS - almost certainly fatal event - massive midline shift
Interpret
Blood in the RHS ventricles
What is CT angiography used for in stroke Ps?
To identify Ps suitable for thrombectomy
Interpret
Left middle cerebral artery occlusion
Interpret
Left and right carotid occluded
What is a perfusion CT used for?
What type of stroke is MRI good for?
High sensitivity and specificity in ischaemic stroke
What are DWI scans good for?
Ischaemic stroke - will show infarcts as bright white for up to 10 days later
What are ADC scans?
Inverse DWI scans - blood appears black on these.
What is a GRE MRI scan good for?
Blood - appears black
What is a T1 post Gd MRI good for showing?
Tumours
What types of MRI scan are seen here?
Top left - standard T2
Top right - FLAIR
Bottom left - DWI
Bottom right - ADC
What is seen on the attached scan?
Microhaemorrhages - lots of black dots seen
What pathology is seen on each of these scans?
A = big intracerebral haemorrhage
B - very many microhaemorrhages
C - DWI - lots of infarction scattered around
D - superficial siderosis - old blood on surface of brain - looks like tramlines
Interpret
Subdural haematoma
Interpret
Old bilateral subdural haematomas
Interpret
Abnormality - RHS - tumour - darker centre with a ring around it.
Do contrast CT / MRI to confirm - contrast will light up around the tumour
What is the treatment of a subarachnoid haemorrhage?
Which sinus on X-ray is always asymmetrical?
Frontal sinus
What does a FLAIR sequence do?
Is a T2 MRI but the CSF fluid is removed from the scan
Which scan is the best modality to evaluate the cerebrum?
MRI
What is the name of the folds of bowel seen on Xray?
Small bowel = valvulae conniventes
Large bowel = haustra
What diameter should the small bowel not exceed?
3mm
What is an alternative to barium enemas for patients?
Virtual colonoscopy (CT colonoscopy)
Interpret
Small bowel obstruction - can tell it is small bowel because the valvulae conniventes go the whole way across the bowel
Interpret
Large bowel obstruction (due to distal bowel tumour)
Interpret
Perforation of the bowel - can tell because the bowel appears to have a white outline
= Rigler’s sign
What is Rigler’s sign
The white outline of the bowel caused by perforation
Interpret
Perforation - is a thin crescent of air (white solid arrow) under right hemidiaphragm
Interpret
Kidney stones
Interpret
AAA
What is the bowel diameter rule for abdominal x-ray?
3-6-9 Rule
When are valvulae conniventes normally seen on XR?
When the bowel is dilated.
How does bowel obstruction present on AXR?
What imaging can be used to confirm a diagnosis of bowel obstruction?
What sign seen on X-ray can indicate a perforation?
Rigler’s sign
What is the best imaging to confirm the site of a bowel perforation?
CT
What is this condition?
Which is the best imaging for seeing paralytic ileus?
AXR best
CT will show
How can you tell the difference between a paralytic ileus and bowel obstruction on AXR?
No transition point is seen - bowel is distended the whole way through.
What is sigmoid volvulus?
Twisting / torsion of the sigmoid colon around its mesentery causing obstruction.
What is the mortality rate of sigmoid volvulus?
25-30% often from bowel ischaemia.
What sign on AXR indicates sigmoid volvulus?
Coffee bean sign - sigmoid colon full of gas forms the inverted U shape.
Arises in the pelvis, lacks haustra and extends to the RUQ
What percentage of volvulus cases involve the caecum?
10%
How can you tell the difference between a sigmoid volvulus and caecal volvulus on AXR?
How can volvulus present on CT?
How does intussusception present on US?
Target or bulls eye sign
How can you confirm the diagnosis of intussusception?
How can intussception be reduced?
Contrast enema for both diagnosis and reduction.
What mode of imaging is commonly used to diagnose appendicitis?
How will it present?
Ultrasound
CT only required for complex cases.
Will present as an abnormally dilated appendix with fluid debris.
What pathology is seen here?
What pathology is seen here?
How can IBD appear on Xray?
Which is the imaging of choice to confirm extent of disease in IBD?
CT
Which is the imaging of choice for IBD in younger Ps?
MRI
What specialist MRI can be used for IBD?
MRI Enterography
Which imaging can show fistulae from Crohn’s disease?
What abnormal signs can you spot on this erect CXR?
Right lower lobe pneumonia presenting with upper abdominal pain.
What can be done to assess the speed of colonic transit?
If a patient has swallowed a foreign body - when should you do a CXR
If you think it will show up on CXR
Why are swallowing of batteries often fatal?
Generates electrical current in contact with soft tissue. NaOH forms - causes severe / fatal mucosal damage = perforation
What fluroscopy of the GI tract can be done?
What is fluoroscopy?
Fluoroscopy is a radiological technique, which gives a real time video image on television monitors. It is useful for seeing dynamic bodily functions, such as the swallowing action. We use a range of dyes which can be drunk or introduced through a variety of catheters depending on the part of the body.
What is a barium swallow used for?
What is seen here?
What is a videofluroscopy used for?
What has barium meal been replaced by?
Rarely done as endoscopy is preferred
What has barium enema been replaced with?
Mainly replaced by CT Colonoscopy
What is used for female patients for urgency and difficulty defecating?
What can be used to investigate perianal fistulas?
What is endoscopic ultrasound used for?
What IR procedure can be sued for GI haemorrhages?
How can you tell if an NG tube is placed correctly on an XR?
Should bisect the carina, cross the diaphragm in the middle and the distal tip should be seen below the left hemidiaphragm
What is seen in this chest imaging?
