Download - Dynamic MR Imaging of the Knee - ISMRM 2011
Self-Navigated Kinematic Imaging of the Knee
Liheng Guo1, Antonio J. Machado Segundo2, J. Andrew Derbyshire3, John A. Carrino2, Daniel A. Herzka1
1 Department of Biomedical Engineering Johns Hopkins School of Medicine, Baltimore, MD, U.S.A.
2 Department of Radiology and Radiological Science Johns Hopkins School of Medicine, Baltimore, MD, U.S.A.
3 National Heart, Lung, and Blood Institute. National Institutes of Health, Bethesda, MD, U.S.A.
Adapted from: Podium Presentation, 19th Annual Meeting of the International Societyfor Magnetic Resonance in Medicine (ISMRM). Montreal, Canada, 2011
MOTIVATIONMusculoskeleto (MSK) MR imaging:
Superior soft-tissue contrast (unmatched by CT, X-Ray)Heavily used in diagnostic imagingDynamic images highly desired
“Movie” reveals joint, tendon motion Invaluable in functional evaluation
Blemker and McVeigh, ISMRM, 2006 (Abstract 3619)
Current Image QualityLow resolution
K-SPACE TRAJECTORIESTR 1 TR 2
… …Time
Derbyshire, et al. Efficient implementation of hardware-optimized gradient sequences for real-time imaging. Magnetic Resonance in Medicine, 64: 1814–1820. 2010.
METHOD: MOTION MEASUREMENTS
+ –
+ : 5500 projections (70sec)
– : 5500 projections (70sec)
Time
MRI machine programmed to also measure knee motion
HUMAN IMAGING EXPERIMENTSSiemens Verio 3T MRI, custom-programmedStandard Knee Coil: ~20° range of motionRepeated extension / flexion, ~1 minute,
~3sec/cycle
Knee coil
OBTAINED MOTION MEASUREMENTS
+ projections
– projections
+ projections
– projections
+ projections
– projections
MOTION CYCLE TRACKINGMotion cycles extracted by custom algorithm
+ projections
– projections
+ gating curve
– gating curve
Trigger corroboration
TRs
1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10
IMAGING DATA SORTINGData sorted into movie frames
… …
…
+ projections
– projections