KNEE MRI PROTOCOL & REFERENCE IMAGES





Prescribing sagittal images. Images are obtained no more

than 10° oblique to a perpendicular to a line connecting the

 posterior femoral condyles (the bicondylar line). Alignment 

of sections directly along the long axis of the anterior

 cruciate ligament (ACL) in the axial plane is discouraged; 

this will often lead to overly oblique sagittal images with 

degraded visualization of the menisci and other knee 

structures.



KNEE MRI SEQUENCES

AXIAL PD FAT SAT
AXIAL T1 FSE NON FAT SAT
AXIAL T2 FSE FAT SAT
 SAG PD
 SAG GRE T2
 SAG PD FS TO ACL
 SAG T2  FSE FAT SAT
 COR PD
 COR STIR

KNEE MRI ARTHROGRAM SEQUENCES

SAG T1 SE  FAT SAT
SAG PD FSE NON FAT SAT
COR T1 FSE FAT SAT
COR T1 SE FAT SAT
AXIAL T2 FSE FAT SAT
AXIAL T1 SE FAT SAT




AXIAL KNEE MRI PLANNING
  

Cover from the top of the patella to about the tibial tuberosity, but at least into the tibial plateau.
Image from distal quad tendon through patellar tendon insertion. 

Parallel Sat Band


CORONAL KNEE MRI PLANNING








Prescribe plane with line parallel to femoral condyles.  Image entire knee

- Angle parallel to the posterior femoral condyles on the Axial scout
- Angle perpendicular to the tibial plateau on the Sagittal scout, or parallel 
to the tibial shaft if the tibial plateau is hard to assess
- Cover from the anterior cortex of the patella to as far back as possible 
(cover at least 1 slice posterior to femoral condyles and cover fibular 
head)
- Superior Sat Band



SAGITAL KNEE MRI PLANNING

CORONAL REF FOR SAG KNEE



NORMAL SAG PLANNING



 Scan from the medial to the lateral femoral condyle.Perpendicular to COR. Angled perpendicular to Tibial Plateau on COR Cover at least 1 slice out of both menisci.


 Superior Sat Band







KNEE ACL PLANNING

COR REFERENCE LINE FOR KNEE JOINT MRI ACL PLANNING


ACL PLANNING KNEE JOINT


KNEE PLANNING FOR ACL-Slices are angled to optimize visualization of the ACL (actually slightly over-obliqued in this case).The Sagittal PD FSE sequence is designed to image the Anterior Cruciate Ligament (ACL). The orientation is a sagittal oblique along the orientation of the ACL.



 KNEE MRI GENERAL COMMENTS

- Only angle to the ACL in the coronal plane for the Sag PD FS sequence; 
do not angle in the axial plane
- Cover all of the patella on all sequences

COIL
- 15 Channel Knee Coil for Thin knees
- Body coil for the Largest knees
- Center coil over the mid-point of the Patella (or Joint line)

POSITIONING
- Supine with knee fully extended
- Try to keep knee straight, but only if comfortable for the patient (limit 
internal and external rotation)

















The Sagittal PD fat suppressed CSE sequence is designed to image the menisci. Cartilage is also well visualized with this sequence, obviating the need for dedicated gradient sequences on routine studies.







FSE techniques can introduce blur. Though conventional spin echo (CSE) sequences take longer to acquire, they are the most accurate for meniscal pathology. (rollover for PD FSE vs PD CSE fat sat)







The Coronal PD fat suppressed sequence is designed for the evaluation of the collateral supporting structures, especially when an injury is acute/subacute.  Meniscal tears are also often detectable in the coronal plane.






Inversion recovery (above left) is the most sensitive sequence for detection of bone marrow edema and in the axial plane also allows for evaluation of the patellar cartilage.3.0 T PD fat saturation (above right) allows for more cartilage detail.


KNEE ARTHROGRAM

  • The T1 fat suppressed post arthrogram sequence is most beneficial for evaluation of post-operative menisci. Intra-articular gadolinium helps differentiate between post-operative high signal that can be seen on PD sequences versus a retear of the meniscus. The gadolinium will enter a retear in the meniscus. The sequence can also help in evaluation of cartilage and ACL reconstructions

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