SPECIAL - Neuro MRI Spectroscopy

Question 1

Normal peaks in Hunter’s angle

Answer 1

Cho < Cr < NAA (N-acetyl aspartate)

Question 2

PPM for Cr and NAA

Answer 2

Cr at 3 PPM, NAA at 2 PPM

Question 3

Decreased NAA, increased lactate

Answer 3

MELAS

Question 4

Elevated NAA

Answer 4

Canavan disease; NAA is normally the highest peak, but higher than normal

Question 5

Elevated alanine

Answer 5

meningioma

Question 6

Elevated glutamine (Glx)

Answer 6

hepatic encephalopathy; Glx is a “ramp” up to the NAA peak

Question 7

Decreased Cho, decreased NAA, elevated lactate

Answer 7

radiation necrosis

Question 8

Elevated Cho, decreased NAA, elevated lactate

Answer 8

high-grade malignancy (e.g. GBM)

Question 9

Elevated myo-inositol (mI)

Answer 9

Down’s or Alzheimer’s; mI peak is before Cho

Question 10

Significance of Cho

Answer 10

Cho is a non-specific marker for cell turnover (tumor, infarction, or inflammation)

Question 11

Significance of lactate

Answer 11

lactate is seen with aerobic metabolism (necrotic tumors, radiation necrosis, abscess); peak at 1.25 PPM