Imaging

Question 1

What are the types of resonance for MRI

Answer 1

White:Hyperresonant

Black:Hyporesonant

Question 2

How to describe the different forms of imaging

Answer 2

MRI:Resonance
CT:Density
X-Ray:Opacity
Ultrasound:Echoic

Question 3

Pros and Cons of Ultrasound

Answer 3

Pros

1. Bedside portable
2. No Radiation: Can use for pregancy
3. High specificity/sensitivity for condtions like cholelithiasis
4. Low cost

Cons

1. Operator dependent
2. Not as sensitive for obscured structures eg duodenum

Question 4

Pros and Cons of CT

Answer 4

Pros

1. 3D spatial imaging
2. Good visualization
3. Diagnostic of conditions with contrast eg HCC + faster/cheaper than MRI

Cons

1. Radiation
2. More expensive than ultrasound
3. Poor differentiation of soft tissue than MRI

Question 5

Pros and Cons of MRI

Answer 5

Pros:

1. Good soft tissue differentiation
2. 3D spatial views
3. No radiation

Cons:

1. Slow
2. Expensive

Question 6

Mimickers of stroke

Answer 6

1. Cerebral Venous Thrombosis
2. Epidural/Subdural Hemorrhage
3. Subarachnoid Hemorrhage from ruptured aneurysm
4. Parenchymal bleeds
5. Vascular malformations
6. Tumours

Question 7

CT early signs of Acute MCA Infarct

Answer 7

1. Dense MCA
2. Loss of insular ribbon
3. Hypodensity of tissue(becomes darker)
4. Sulcal effacement/blurring
5. Lentiform nucleus obscuration