Showing posts with label MRI REFERENCE LINES. Show all posts
Showing posts with label MRI REFERENCE LINES. Show all posts

ELBOW MRI REFERENCE LINES

IN THIS ARTICLE:
  • AXIAL REFERENCE LINE
  • CORONAL REFERENCE LINE
  • SAGITAL REFERENCE LINE



AXIAL REFERENCE LINE- Perpendicular to Coronal
Use COR to angle parallel to elbow joint (parallel to capitellum and trochlea),Cover from 1 slice distal to radial tuberosity up as far as the slices go. Parallel Sat Bands (above and below)

CORONAL REFERENCE LINE
Use axial LOC to angle parallel to anterior portions of the capitellum and 
trochlea (or parallel to humeral epicondyles)   
Use sagittal LOC to angle parallel to humerus/radius/ulnar plane, but 
closer to plane of radius if minimally flexed (if markedly flexed elbow, 
then angle between anterior humerus and the radius)

SAGITAL REFERENCE LINE
Perpendicular to both Coronal and Axial sequences,Cover 1 slice outside of both humeral epicondyles


AXIAL REFERENCE LINE IN MRI PLANNING

AXIAL


AXIAL REFERENCE LINES

CORONAL REFERENCE LINE IN MRI PLANNING


CORONAL ELBOW REFERENCE LINES

SAGITAL REFERENCE LINE IN MRI PLANNING 


SAG ELBOW REFERENCE LINES


FABS  VIEW

  Fig. 1.
Photograph shows patient positioning for flexed abducted supinated view: patient is positioned prone on MRI table with elbow in flexed abducted supinated view position. Notice position of arm, flexed at elbow and abducted at shoulder with supinated forearm, thumb up.


 In general, it was preferable for the patient to lie prone for these views. The shoulder was abducted 180°, with the arm beside the head. The elbow was flexed to 90°, with the forearm supinated, thumb up, and a shoulder phased array coil was placed around the elbow . The position is referred to in this article as the flexed abducted supinated view, but usually in our practice it is termed the “FABS view,” meaning the flexed elbow with the shoulder abducted and the forearm in supination view.
  Fig. 2.


Localizer MR image with lines shows slice positioning for flexed abducted supinated view. Notice sections, sagittal to long axis of body but coronal to anatomy at elbow. Ideal angulation is planned along distal biceps brachii tendon, but often, as here, this structure is not clearly visible on localizer images. In this case, sections nearly perpendicular to radius provide reasonable and reproducible imaging plane.




Coronal T1
Coronal T1 and PD fat suppressed sequence are well suited for evaluation of collateral ligament and common extensor/flexor tendon group patholgy as well as epicondylitis.
COR PD FAT SAT


AXIAL T1
Axial T1 and PD FSE fat suppressed sequences evaluate the tendons of the Biceps Brachii and Brachiallis muscles transversely as they insert onto the Radius and Ulna respectively.  The distal Triceps tendon is also well evlauated in this plane.
AXIAL PD FAT SAT


T1 SAG
Sagittal T1 and PD FSE fat sat sequences evaluate the tendons of the Biceps Brachii and Brachiallis muscles as they travel distally to instert onto the Radius and Ulna respectively.  They also help evaluate the Radial head for radiographically occult fractures.  The distal Triceps tendon is also well evlauated in this plane.
PD FAT SAT SAG


ELBOW ARTHROGRAM
Coronal T1 fat saturated arthrogram is useful for evaluation of the collateral ligaments and cartilage surfaces.


READ MORE ABOUT:


MRI ELBOW PROTOCOL

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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