1. Eric Lévêque, Benoit Hainaux,
HOW I DO IT ? KNEE IMAGING
Eric Lévêque, Benoit Hainaux,
Nathalie Chemla M.D
Paris V Clinic, France

2. COIL Dedicated 8 channels phased array Or flex coil type
Closer to B0 center for a better FAT SAT
Use flex coil type with positioning system
Put the coil in the middle of B0, the opposite leg against the tunnel

3. PATIENT POSITION Lying on his back Slightly flexed by an angle of 15°
External rotation of the lower limb by an angle of 10/15°
Mustn’t contract thigh and move foot
to clear the ACL (Anterior cruciate ligament) from the intercondylar notch (Blumensaat line)
to verticalize ACL, maintained with sand bag
Mustn’t move the entire body (domino effect)

4. SLICES POSITION
Sagittal : Internal rotation by 5° compared with the transcondylar line. Overflow of 2 or 3 slices in external to cover the head of fibula and femoral biceps
Coronal : Parallel to the bi-condylar plane. Cover menisci forward and head of fibula and biceps femoris muscle backward
Strict axial from the top of the patella to the anterior tibial tuberosity fb

5. CRITERIA OF SUCCESS fb pm
ACL cleared from the blumensaat line on sagittal plane and verticalized on coronal plane
Insertion of biceps femoris and popliteus muscle on posterior coronal slices
Cover menisci in coronal plane
From top of patella to att fb pm

6. KNEE IMAGING MRI accurate non invasive technique
Used to asses internal derangement of knee
2 principals methods
Current conventional two dimensonial (2D) MR imaging
More recenntly, three dimensional (3D) Isotropic MR (CUBE).

7. WHAT IS CUBE? 3D Séquence FastSpin écho Isotropic
Multi-contrast ( T1, PD, T2, FLAIR )
With or without Fat Sat

8. WHY DO WE USE CUBE? GOAL: easy to use on knee MRI
THREE IMPORTANT CONDITIONS:
Total time < 3 DP FS sequences
Same contrast as 2D (méniscus, ligaments, bone marrow and cartilages )
Quality of reformat as good even better than 2D

9. MRI OF KNEE Time consuming Thick sections Small gaps between sections
2D MR
ISOTROPIC 3D MR
Time consuming
Thick sections
Small gaps between sections
Partial volume artifacts
3 planes,sagittal, axial and coronal
Thin section data acquisition
Without intersection gap
Imagis reformatted in arbitrary planes
Helpfull in analysis of complex structures
DP FAT SAT ET FAST SPIN ECHO

10. 2D versus 3D MRI DP FAT SAT Non isotropics pixels.
2D protocol
3D protocol
Time 2D three planes= 3mn07 +2mn+2mn + 20s of pré scanning for each séquence (60s)
DP FAT SAT
Non isotropics pixels.
Multiplanar reformat not possible.
Gap between slice is bad for good visualization of cartilage defects.
Time 3D cube=6’30 +/- 30s + 20s of pré scanning
(less time to permorf study of all knee)
Isotropic pixel
Fast Spin Echo
Multi contrast T1, T2, DP, T2 FLAIR
With or without FAt SAT

11. CORONAL, SAGITTAL AND AXIAL REFORMATS OBTAINED AFTER 3D CUBE ACQUISITION

13. CUBE APPLIED TO PATHOLOGY
CARTILAGINOUS DEFECT
MENISCAL TEARS
ACL EXPLORATION
OTHERS….

14. T2 MAPPING

15. CUBE AND PATHOLOGY
ARTHRO CT
CARTILAGINOUS DEFECT

16. CARTILAGINOUS DEFECT 2D
3D REFORMAT 0,5 mm

17. MENISCAL TEAR AND CARTILAGINOUS LESION

18. BUCKET HANDLE MENISCAL LESION
Cobra sign
3D REFORMAT

19. 2D/3D

20. ACL : 2 distincts ligaments
AM Ligament
FOR A LONG TIME WE HAVE THINK THAT acl is unic ligament
Yellow star red star
Now we know that it is in fact done of two groups of fibers
PL Ligament

21. « d play with track ball
3D CUBE ACQUISITION

22. 3D MRI MULTIPLANAR REFORMAT
Than you can give to the surgeon good slice in the plane of ligament

23. PARTIAL TEAR OF ACL

24. MR ARTHROGRAPHY
SAGITTAL FST1
SAGITTAL FAT SAT FST1

25. 3D CUBE MRI
First developped to improve cartilage analysis because good contrast betwween joint fluid (hyper T2) and cartilage (intermediar signal) and gap between slice in 2D acquisition not good for good visualization of cartilage defects.
Than proved superiority in analysis of ligaments and meniscus
Princial hardware: motion artifact

26. CONCLUSION
Favorable tissue contrast of isotropic 3D fast SE in the assessment of ligaments, menisci, and cartilage yields high sensitivity and specificity that seems tu us better with those yielded by conventional 2D fast SE MR imaging