1. MRI OF PROTHETIC IMPLANTS IN MSK
Nathalie CHEMLA MD, Eric PESSIS MD,
Clinic Paris V
Cochin Hospital Paris
CCN Saint Denis
France

2. MRI OF PROTHETIC IMPLANTS IN MSK
The use of MRI in the presence of metallic hardware has traditionally been limited by susceptibility artifacts generated by the presence of the metallic components.
With arthroplasty being increasingly used to relieve joint pain, imaging of patients with large metal implants represent a significant part of the radiologist’s daily practice

3. PULSE PARAMETERS MODIFICATIONS ON SE
Maximize the bandwidth
Imaging at 1.5 T, instead of 3 T
Thin sections
Large matrix (encoding phase perpendicular to métal axis)
High number of excitations
A number of modifications of pulse parameters can be easily applied to conventional fast spin-echo (FSE) techniques to improve visualization of the soft tissues surrounding an arthroplasty .SUCH AS

4. STIR AND METAL ARTIFACTS
Use STIR imaging to avoid failure of fat suppression (instead of frequency-selective fat suppression

5. MAVRIC ( multiacquisition variable-resonance image combination )
However, these factors can be not sufficient.
More recently, new technique such as (MAVRIC) : a method to correct displacement artifacts

6. STIR MAVRIC
Il looks like the head had cross the cotyl

7. MAVRIC 3D Fast Spin Echo PD technic
With or without IR (fat sat effect)
multiple overlapping volumes .
Helps eliminate through-plane distortions and reduce in-plane artifacts.
The combined images have minimal artifact and include signal from a wide range of frequency offsets near metal.

8. MAVRIC Maximize bandwith
FOV: minimum 18 cm to avoir aliasing wrap-around
Minimum 5 mm slices
110° angle to reduce SAR (specific absorbtion rate)
High matrix
To opyimize

9. TENDINITIS AND STRESS FRACTURE
screw
TENDINITIS AND STRESS FRACTURE

10. CUBE VERSUS MAVRIC
Cancellous bone oedema because of chondropathy

12. Hip arthroplasty: osseous integration
Using conventional SE T1 and STIR MR imaging technique, the regions of bone around the metal implants are obscured by artifacts (white arrows).
MAVRIC image show improved clarity and help to visualize bone-stem interface (yellow arrows) T1
STIR
MAVRIC

13. Hip arthroplasty :osseous integration
Complete osseous integration of a cementless hip arthroplasty implant : direct contact between the implant and the surrounding trabecular bone without separation.
Using conventional FSE T2 with fat suppression MR imaging technique, the regions of bone around the metal femoral implant is obscured by artifacts (white arrow)
MAVRIC image show improved clarity and help to visualize direct contact of the implant (yellow arrow) and the surrounding cancellous bone
FSE T2 with fat suppression
MAVRIC

14. TOTAL KNEE ARTHROPLASTY: OSTEOLYSIS
Periprosthetic osteolysis over the anterior aspect of tibial peg ( red arrow) well visualized on plain film and
Not visible on FSE T2 with water excitation (IDEAL) MR image
FSE T2 IDEAL

15. Total knee arthroplasty: osteolysis
Periprosthetic osteolysis over the anterior aspect of tibial peg (red arrow) is well visualized on T2 MAVRIC image and
Not visible on correspondant FSE T2 with water excitation (IDEAL) image
Sagittal T2 MAVRIC
FSE T2 IDEAL

16. Lumbar disk arthroplasty at the L4-L5 level
Conventional plain film and MR images of the lumbar spine (SE T1 and FSE T2 sequences) show severe artifacts from orthopedic hardware that obscure the anatomy and limit evaluation of the spinal canal with MRI (yellow arrows).
Corresponding MAVRIC image show significant reduction of artifact in the spinal canal (white arrow).
SE T1
FSE T2
T2 MAVRIC

17. Screw fixation of a sacroiliac joint disruption
Conventional MR images of the lumbar spine (SE T1 and FSE T2 sequences) show severe artifacts from a screw that obscure the anatomy and limit evaluation of the spinal canal with MRI (yellow arrows).
Corresponding MAVRIC image show significant reduction of artifact in the spinal canal (white arrow).
FSE T2
SE T1
FSE T2

18. Screw fixation of a sacroiliac joint disruption
Conventional sagittal MR image of the lumbar spine (FSE T2 sequence) shows severe artifacts from a screw that limit evaluation of the spinal canal (yellow arrow).
Corresponding MAVRIC images shows significant reduction of artifact in the spinal canal (white arrow).
FSE T2
T2 MAVRIC
T2 MAVRIC

19. SE and corresponding MAVRIC images show significant reduction of artifact in the spinal canal especially on axial plan.
T2SE
MAVRIC
Is there disk herniation ?
Mavric: no disk hernation

20. CERVICAL SYRINX BETTER ANALYSIS WITH MAVRIC

21. Conclusion
Multiacquisition Variable-Resonance Image Combination (MAVRIC) Method
Allows to reduce substantially artifacts from metal implants at MRI
Improve visualization of metal-to-bone interface
Improve the visualization of soft tissue near and far the metallic implant
Evaluation of metal implants and adjacent bone or tissue is enhanced with MAVRIC images

22. THANKS TO DR ERIC PESSIS
THANKS TO ERIC LÉVÊQUE

23. Bibliography
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3. Hayter CL, Koff MF, Shah P, Koch KM, Miller TT, Potter HG. MRI after arthroplasty: comparison of MAVRIC and conventional fast spin-echo techniques. AJR American journal of roentgenology. 2011;197(3):W
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5. Nawabi DH, Hayter CL, Su EP, et al. Magnetic resonance imaging findings in symptomatic versus asymptomatic subjects following metal-on-metal hip resurfacing arthroplasty. The Journal of bone and joint surgery American volume. 2013;95(10):