0:00

Sequences in the axial projection.

0:04

Here, the choices are a little more variable.

0:09

You get to choose.

0:11

But you don't have to go in there and

0:12

talk to your technologist for every case.

0:14

You educate your technologist on what to

0:17

choose based on the historical diagnosis.

0:21

So you may have some flexibility in your

0:24

wrist protocol and pulsing sequences.

0:27

I personally like a short axis T1 and a short axis T2

0:33

if I am not hunting for acute active tendon pathology.

0:38

For instance, if I'm looking for a mass or

0:42

entrapment neuropathy, I'll pick these two sequences.

0:46

The other thing I do in my short axis

0:48

projection is I immediately figure out

0:51

how the technologist positioned the wrist.

0:54

If the ulnar styloid is pointing dorsally,

0:58

that means that the hand is in pronation.

1:02

Whereas if the styloid rolls around towards

1:06

the medial side or more palmarly, that means

1:10

we're in a supinated or neutral position.

1:14

That helps me get my bearings and

1:16

the relationships, tendons, to their

1:19

underlying or overlying bony structures.

1:23

I use this projection to look at the conformity

1:26

and relationship between the ulna and the radius.

1:32

It is also an important projection to look

1:34

at tendons as they course straight at you.

1:38

Now unlike the finger and some other

1:40

parts of the body where I will oblique my

1:43

axials, here I do them straight at you.

1:47

Orthogonally, and I make sure that the technologist

1:50

has positioned the wrist in a neutral position.

1:54

Not ulnar deviated, not radial deviated, although that

1:59

might be a projection we choose a little bit later on.

2:04

Especially for assessment of the

2:06

scapholunate and lunotriquetral ligaments.

2:09

But I want the wrist to be neutral, straight ahead.

2:13

I don't want to see any deviation of the wrist.

2:16

The metacarpals, with the exception of maybe

2:19

the pinky, which often floats off laterally,

2:22

or, sorry, sorry, medially on its own.

2:26

In terms of how far I go, I want to make sure that

2:30

my axials go from at least proximal to the distal

2:34

radial ulnar joint, which, by the way, this one does.

2:36

It goes pretty far back.

2:38

Let's look at it.

2:38

It goes all the way back here.

2:40

Probably didn't need to go quite that far.

2:42

It could have stopped right there.

2:43

And I want to make sure that the

2:45

distal extent of my axials goes past

2:48

the carpo-metacarpal junction.

2:50

And this does so very nicely.

2:54

The short axis view is excellent

2:57

for identification of masses.

3:00

Because you're used to the axial

3:02

projection from your days in CT.

3:07

The axial projection is also invaluable

3:10

if you have the right sequences, namely heavily

3:13

water-weighted sequences, to search for loose bodies.

3:17

And finally, another strength of the short axis

3:20

projection is to look for entrapment neuropathies

3:24

in the median nerve, so-called carpal tunnel

3:27

syndrome, or in this area known as Guillain's

3:31

Canal, where the ulnar nerve, artery, and vein live.

3:36

More on that a little bit later

3:37

on, when we drill into anatomy.

3:41

Remember also that the relationships

3:45

of tendons to the underlying bone varies

3:47

with position, as mentioned earlier.

3:50

And when you are in extreme pronation, the extensor

3:54

carpi ulnaris may perch or sit on this little ridge.

3:58

And that in itself is not abnormal.

4:02

Extremes of pronation and extremes of

4:05

supination may alter, as discussed,

4:08

the relationships of certain tendons

4:11

to the adjacent bones and grooves.

4:14

And one of these is the ECU or extensor carpi ulnaris.

4:19

Most of the time, this is not abnormal.