MRI of the locus coeruleus MRI of the locus coeruleus and substantia nigraand substantia nigra

Dr Timothy RittmanDr Timothy Rittman

Academic Foundation Year 2Academic Foundation Year 2

Locus coeruleusLocus coeruleusSubstantia nigraSubstantia nigra

Imaging of SNImaging of SN

Sasaki et alSasaki et al

Effect of MT and SPIREffect of MT and SPIR

Magnetisation transferMagnetisation transfer

NeuromelaninNeuromelanin Macromolecules = short T2*Macromolecules = short T2* Off resonance radiofrequency pulseOff resonance radiofrequency pulse Transfer of energy from macromoleculesTransfer of energy from macromolecules

waterwater ?iron?iron

SPIRSPIR presaturation pulsepresaturation pulse hidden MT effecthidden MT effect

MethodMethod

T1 MRIT1 MRI Repetition time 757msRepetition time 757ms Echo time 9.1msEcho time 9.1ms Voxel size = 0.47x0.47x2.75mmVoxel size = 0.47x0.47x2.75mm33

SPIRSPIR 7 healthy volunteers7 healthy volunteers MT not possible due to SAR limitsMT not possible due to SAR limits

Results - Substantia nigraResults - Substantia nigra

Results - Locus coeruleusResults - Locus coeruleus

ConclusionConclusion

The substantia nigra and locus coeruleus The substantia nigra and locus coeruleus are visible using T1 weighted imaging with are visible using T1 weighted imaging with SPIRSPIR

Most likely due to an MT effectMost likely due to an MT effect Sequence is sensitive to neuromelaninSequence is sensitive to neuromelanin Specificity remains to be testedSpecificity remains to be tested

Thanks to…Thanks to…

Prof AuerProf Auer All in Academic RadiologyAll in Academic Radiology All at Sir Peter Mansfield Magnetic All at Sir Peter Mansfield Magnetic

Resonance CentreResonance Centre Prof Mahida and Prof HawkeyProf Mahida and Prof Hawkey