1. Declaration of Relevant Financial Interests or Relationships
ISMRM
20th ANNUAL MEETING & EXHIBITION
“Adapting MR in a Changing World”
Declaration of Relevant Financial Interests or Relationships
Speaker Name: Jennifer Moroz
I have no relevant financial interest or relationship to disclose with regard to the subject matter of this presentation.

2. Estimation of the Arterial Input Function in a Mouse Tail from the Signal Phase of Projection Profiles
J. Moroz, A. Yung, P. Kozlowski, S. Reinsberg
University of British Columbia

3. The Arterial Input Function (AIF)
Describes the time course plasma concentration of
contrast agent in a vessel
Accurate AIF required for modeling
* Improve accuracy with higher temporal resolution *

4. AIF Measurement from Phase
Signal Phase
Varies linearly with concentration (mod 2p)
Greater SNR than signal magnitude
Fairly insensitive to T2* relaxation
Phase evolves differently in vessels
Requires flow compensation

5. Phase-Concentration Calibration (Projection data)
Theoretical Experimental

6. High Temporal Resolution Improves AIF Accuracy
Rapid enhancement
post injection
Curve shape not obvious
Peak concentration?
Peak location?
AIF sampling rates
Mouse
Lyng et al. (1998) – 33 s
Ragan et al. (2010) – 84 ms
Fruytien et al. (2011) – 1.19 s
Rat
McGrath et al. (2009) – 0.5 s

7. Methods: Mouse Tail Surface Coil
Spatial Resolution = 58 mm
1-5 pixels per vessel (projections)

8. Methods: Use of Projections
Solve AIF(t) = (f(t) – fpre-injection) / (Ccalibration* TE)

9. Results: Projections-based AIF
in a Mouse Tail

10. Expected Functional Form of AIF

11. Expected Functional Form of AIF

12. Conclusions
Early time points of AIF may be dependent on injection protocol
Injection protocol must match if using a population averaged result
Measure AIF for each experiment
AIF may be measured from projection profile
Increased temporal resolution
Limitation: tissue enhancement
Flow compensation required for AIF in mouse tail

13. Acknowledgements Funding Agencies Lab Personnel Kelly McPhee
Jennifer Baker

14. Future Plans

15. Flow Compensation is Required