1. Clinical application of MR perfusion – MSK oncology
Basics Of MRI: How I Do It? AFIIM -ISRA 2015
Clinical application of MR perfusion – MSK oncology
Tips and Tricks
Pedro Teixeira MD, PhD

2. Introduction Limits of conventional MRI on MSK oncology
Potential applications of MR perfusion
Difficulties for clinical application
- Complex acquisition protocols
- Data post processing
- Interpretation and reproducibility

3. The bases How does perfusion imaging works? Perfusion imaging methods:
- Ultrasound
- CT
- MRI
Petit tableau avantages et inconvenients…
Artery
Tumor
Time

4. Sequence choice Contrast enhanced Gradient Echo K space filling
Full K space filling:
Low spatial resolution
Optimal quantitative analysis (permeability)
Partial K space filling:
Good temporal and spatial résolution
Angiography-like images
Visual analysis +++

5. 4D MR angiography - bases
Time Resolved MRA sequences (TRICKS, TWIST…)
K space is divided in 4 concentric zones A, B, C, D
Zone A (Image contrast) is read more frequently
An initial full acquisition (zones A, B, C and D) is used as a subtraction mask D C B A
temps 1 2 3 4 5 6 7 8 9 10 11 12 13 … A B C D A B A C A D A B A
… A B C D
masque
Masque

6. Sequence choice
TRICKS
FSPGR
Visual and semi-quantitative parameters: Partial filling
Quantitative parameters: Full k space filling

7. ? Protocol FAQ Which injection delay and rate should be used?
How much contrast do we need?
What is the acceptable temporal resolution range?
What is the optimal acquisition length?
Artery
Tumor
Time (s) ?
Delay dependent on protocol… mask 40s… 10 sec delay for superior limb and 15 sec delay for inferior limb
0,5 ml/s
0,2 ml/kg
TR: 5-10 seconds
Length : 3-7mins

8. Types of perfusion parameters available
Data analysis
Types of perfusion parameters available
Visual
Semi-quantitative
Quantitative*
* Research

9. Adjacent artery as standard of reference!
Visual Parameters
Enhancement intensity
Enhancement speed
Néovaisseux
Adjacent artery as standard of reference!
images

10. Semi-quantitative parameters
Slope
Maximal enhancement
Enhancement integral
Time-to-peak
Arterial-tumoral peak delay

11. Enhancement curve morphology
Int
Time
Type I
Int
Time
Type II
Type III
Type IV
Type V
Int
Time
Int
Time
Int
Time
Fig. 1 – Schema representing the perfusion curve morphology types described by van Rijswijk CSP (17).
van Rijswijk et al.

12. Data analysis Data comparison Which standard of reference?
Temporal parameters
- Arterial input as the standard of reference

13. L’interprétation Intensity related parameters - normalization
Integral du rehaussement

14. Clinical applications
Limited role for tumor characterization
Can aide in the identification and follow-up of tumors with a known perfusion behavior
Post operative evaluation (fibrosis vs recurrent/residual tumor)
Additional criterion for adjuvant therapy response
Pre biopsy planning

15. 26 year-old female with a dedifferentiated sarcoma of the thoracic wall treated surgically.
Contrôle post opératoire

16. Post-treatment (3 cycles)
54 year-old woman with a distal femur ostéosarcome treated with chemotherapy. Treatment response assessment.
Pre-treatment
Post-treatment (3 cycles)

17. Post-treatment (3 cycles)
Pre-treatment
Post-treatment (3 cycles)

18. Biopsy guidance T1
T2 FS
Find images
T1 GD FS

19. TRICKS MIP

20. Take home messages MR perfusion is clinically available
It can help in the characterization and follow-up of MSK tumors
Optimize the acquisition protocol to the intended clinical use
Beware of inappropriate data comparisons
Thank you for your attention!