radiology slideshow ct & mri ian anderson, 2007. a brief note on ct & mri scans ct is the...

Radiology Slideshow

CT & MRI

Ian Anderson, 2007

A brief note on CT & MRI scans

• CT is the initial investigation of choice for suspected intracranial haemorrhage and stroke

• MRI is much more sensitive to cerebral parenchymal change and is the preferred investigation in most non-emergency situations, especially suspected tumours

• MRI is sometimes used if CT negative & brainstem or cerebellar stroke/TIA suspected

• Blood is generally dark on CT, bright on MRI• Changes due to haemorrhage resolve within days on a

CT scan but may persist for months/years on MRI scan

Question 1

1. What is the most likely diagnosis?

2. Where is the bleed most likely to have come from?

3. How would you expect the patient to present?

1. Acute R extradural haematoma. Note the high density of the haematoma. Slight midline shift is present.

2. They usually develop from skull # => injury to the middle meningeal artery or its branches.

3. H/O trauma, lucid interval btw injury and deterioration in consciousness, severe headache, vomiting, confusion, fits, hemiparesis, brisk reflexes and plantars up, ipsilateral pupil dilation

Question 2

1. What is the most likely diagnosis?

2. Where is the bleed most likely to have come from?

3. How would you expect the patient to present?

1. Low density collection typical of a chronic subdural haematoma, with associated midline shift. Note sickle-shaped collection

2. Bleeding from veins between cortex and venous sinuses, usually secondary to falls/minor head trauma

3. Insidious onset, fluctuating level of consciousness, physical and intellectual slowing, sleepiness, headache, personality change, unsteadiness, localising symptoms occur late

Question 3

1. What is the most likely diagnosis?

2. Where is the bleed most likely to have come from?

3. How would you expect the patient to present?

1. Blood in ventricular fissures

2. 85% due to berry aneurysms, often rupture following straining/exercise

3. Sudden, thunderclap headache (usually occipital), which lasts for hours/days, associated with vomiting, distress, photophobia, neck stiffness

Question 4

1. What type of imaging has been used here?

2. Diagnosis?

3. Management?

1. MRI scan (with gadolinium enhancement to improve sensitivity)

2. Multiple sclerosis

3. Anticholinergics (e.g. oxybutynin), intermittent self-catheterisation, steroid injections, B-interferon, immuno-suppression, bacolfen

Question 5

1. Likely diagnosis?

2. Most likely type?

1. Brain tumour

2. Glioma is the most common type of brain tumour in adults

Question 6: What’s wrong?

Subarachnoid Haemorrhage

Question 7

This man is found unconscious with a huge bump on his head. He is unresponsive, and a head CT is performed.  Name 4 important findings on this patient.

Question 7

1. Epidural Haematoma along the Parietal-Occipital region of the right side of the head.

2. A skull fracture associated with Parietal Bone.

3. A cortical contusion (Arrow) in the left Temporal region, known as a "Contra Coup" injury. 

4. Associated soft tissue haematoma

Question 8: What’s wrong?

Question 8

• Nothing

Question 9

• This 84-year-old woman was brought into the Emergency Department 8 days prior to obtaining this scan.

• She has been bedridden since admission and was note to have no movement of her right extremities and to be aphasic.

Question 9

Question 9

Question 9

• Extensive left hemisphere ischaemic infarction involving territories of the anterior, middle, and posterior cerebral arteries.

• The infarction is known to involve all the lobes of the left hemisphere including frontal, parietal, temporal, and occipital lobes.

• The anterior cerebral artery is also involved in mainly the medial portion of the hemisphere, and there is slight sparing of the anterior cerebral artery in the medial frontal parietal region. 

• Because the event occurred at least 8 days prior, we do not note any extensive mass effect or midline shift on this CT.

• An area of hypodensity in the right occipital lobe, which is an earlier infarction, may also be observed.

Question 10: Spot Diagnosis

Question 10

• Subarachnoid haemorrhage

Question 11: Spot Diagnosis

Question 11

• Subdural haematoma

Question 12: Diagnoses (2)?

Question 12

• Acute extradural haematoma on the right

• Acute traumatic subarachnoid haemorrhage on the left