5. Anatomy and relation study
When you study the anatomy of the elbow, it is good to use the inside-out approach.
First study the bones and then continue with the ligaments and the tendons and then the
surrounding structures.
6. MRI technique
• Scan planes
• Just like in the shoulder you
need to be sure to get the
imaging planes correctly in a
standardized way.
Use the axis of the epicondyles
on a axial localizer to plan the
coronal scan.
The Sagittal images are scanned
perpendicular to the coronal
scan.
• In this way you get very
persistent images and you will
get used to the normal anatomy.
7. Imaging sequences
T1
In every joint that is studied you should
have at least one T1-sequence not only
to look at the anatomy, but also as a back
up for looking at the marrow.
Of course the T2-fatsat images will show
marrow abnormalities, but T1 can be
helpful in telling us what is really going
on.
T1 is certainly used in MR-arthrography.
T2-fatsat
T2 will show us most of the pathology,
whether it is in the bone marrow,
ligaments or muscle because of the high
water content. It can also be used to
image cartilage.
Gradient echo
With gradient echo we can use 3-D thin
sections to image the cartilage and the
ligaments.
In the MR-protocol we do T1 and T2-fatsat in all three imaging
planes.
Sometimes STIR is used.
8. Tendon attachments
Common flexor tendon
Attaches at the medial epicondyle
Ulnar collateral ligament or UCL
Starts at the undersurface of the medial
epicondyle and runs down to the sublime
tubercle, which is the medial side of the coronoid
process.
Common extensor tendon
Originates at the lateral epicondyle.
Lateral collateral ligament
Originates just underneath the attachment of the
common extensor tendon.
Lateral ulnar collateral ligament
This is a somewhat confusing term for a tendon
that also originates just underneath the common
extensor tendon. It swings down behind the radial
head and attaches at the area of the ulna that is
called the supinator crest - see lateral view.
Biceps tendon
Attaches on the radial tuberosity.
Brachialis tendon
Attaches on the coronoid process.
Annular ligament
Attaches on the volar side of the sigmoid notch of
the ulna and runs around the radial head and
attaches on the dorsal side of the sigmoid notch.
Attachment sites
9. Medical epicondyle avulsion
fracture
A fat-suppressed T2 weighted
coronal image in a 15 year old
baseball pitcher reveals an avulsion
fracture (arrow) of the medial
epicondyle apophysis,
10. Ulnar Collateral ligament
If you look at the medial epicondyle you will
notice the posterior bundle as a thin
structure (blue arrow).
The posterior bundle forms the floor of the
cubital tunnel.
A retinaculum covers the cubital tunnel.
Notice that the anterior bundle is much
thicker (white arrow).
As we go distally we'll see that they merge
together to attach to the sublime tubercle
It is normal to see some high signal in the
proximal part (arrow).
11. UCL tear
Remember that the UCL should attach very tightly on
the sublime tubercle.
In this case it doesn't, so even on these two images
you can tell that there is a complete tear.
Notice that there is some marrow edema in the
sublime tubercle.
The mechanism of injury to the UCL is usually chronic
tensile forces, which create micro tears.
This is seen in pitchers and other overhead throwingathletes.
A tear can also occur in a fall on the outstretched hand.
Most commonly there is a complete tear, but
sometimes there is a partial tear which can be very
hard to see.
That is why in these athletes MR- arthrogram is usually
performed.
This is a 18 year old baseball pitcher with medial elbow
pain.
A partial tear is seen creating a 'T-sign‘
Notice that the anterior bundle is intact and firmly
attaches to the sublime tubercle (yellow arrow).
On the next two images there is some soft tissue
edema and more abnormal signal posteriorly (red
arrow). So we suspect pathology of the posterior
bundle.
12. UCL tear
On the axial image we nicely see the
anterior bundle is o.k. (red arrow).
There is only some edema next to it.
However the posterior bundle is not o.k.
This is partial tearing.
We see this occasionally in throwing
athletes, where the anterior bundle is
intact and their elbow is not unstable.
They somehow have torn their posterior
bundle, which causes pain.
They do not need surgery, but it still
may keep them out of the game for
quite a while.
Now here is the last case.
This is a 38 year old male who has been
weight-lifting for 20 years.
He complains of intermittent elbow pain
and popping.
Notice that the UCL is abnormal with
some areas of very high signal indicating
a partial tear.
On the lateral side there is subchondral
edema and cartilage.
This is arthrosis secondary to chronic
instability due to the chronic partial
tearing.
13. Lateral Collateral Ligament
When you look for the radial collateral
ligament, first try to identify the common
extensor tendon, because right
underneath it you will find the radial
collateral ligament (yellow arrow).
As you go more posteriorly you will see
the LUCL - the lateral ulnar collateral
ligament, which sweeps behind the radial
head (white arrows).
The annular ligament is usually difficult to
differentiate from the RCL, but sometimes
it can be identified on a Sagittal MRartrogram.
14. Muscles tendons
The common flexor
tendon originates at the
medial epicondyle.
On a T1W-images the
tendon should have a low
signal intensity (red
arrow).
The common extensor
tendon originates at the
lateral epicondyle.
On a T1W-images the
tendon should have a low
signal intensity (yellow
arrow).
15. Muscles tendons
through the axial images
of the biceps tendon
from the
musculotendinous
junction to the
attachment on the radial
tuberositas.
16. Muscles tendons
The Brachialis originates
from the lower half of the
front of the hummers, near
the insertion of the deltoid
muscle.
It lies deeper than the
biceps brachii, and is a
synergist that assists the
biceps in flexing the elbow.
The thick tendon inserts on
the anterior surface of the
coronoid process of the
ulna.
On a Sagittal view, when you
compare the Brachialis
tendon (yellow arrows) with
the biceps tendon (red
arrows), notice that the
Brachialis is almost all
muscle.
It only has a very short
tendon distally
18. Soft Tissue
Masses & bursitis
On MR a mass was seen
just above the medial
epicondyle, where the
epitrochlear lymph
nodes live.
The mass is very
heterogeneous as is the
enhancement.
Based on the MRfindings you still have to
call this mass
indeterminate.
The final diagnosis was
cat scratch disease
based on high Bartonella
henselae titers.
19. Soft Tissue
Masses & bursitis
Here images of a 26 year old
female who also came with a
mass in the peritrochlear
region.
It looks quite homogeneous
and cystic.
Continue with the post-Gd
image.
Notice the inhomogeneous
enhancement on the MRI and
prominent internal vascularity
on the Sagittal ultrasound
image.
So this was not a cystic mass.
Again this was diagnosed as
indeterminate.
The final diagnosis at biopsy
was Lymphoma