Quality Assessment for Quality Assessment for Routine Clinical MR Routine Clinical MR

SpectroscopySpectroscopy

Diana M. Lindquist, PhDAssistant Professor of Radiology

PurposePurpose Clinical indication: apparently abnormal metabolite

ratios in infant with normal imaging findings. Quality control is as important in clinical spectroscopy

as in research Develop a simple short protocol for quality control in

clinical MRS Localization Spectral data

MethodsMethods Standard head coil and

manufacturer’s phantom

Protocol Axial localizer 3 voxels (8 cm3) PRESS

Total time: 30 minutes

Results: Image UniformityResults: Image Uniformity

Results: Voxel LocalizationResults: Voxel Localization Mean voxel size was

20.2 (± 0.8) by 18.9 (± 0.4) mm2 in-plane

One voxel is adequate; scan time reduced from 30 to 15 minutes

Sample spectraSample spectra

TE 35 ms TE 144 ms

Lac

NAA

CrCho

Results: Metabolite RatiosResults: Metabolite RatiosTE

35msTE

144ms

NAA/Cr 1.50 ± 0.03

1.64 ± 0.04

Cho/Cr 0.84 ± 0.01

0.68 ± 0.02

mI/Cr 0.47 ± 0.02

N/A

ConclusionsConclusions Following implementation of this protocol, we

are now able to detect and correct scanner instabilities.

QC data are useful as a monitor of system performance

Scheduling still difficult even with a 15 minute exam.