Knee Comp

What are some common indications?

medial meniscus tears, lateral meniscus tears, ACL/PCL tears, ligament tears, quadratis femoris injuries, pain, arthritis

How do you identify medial from lateral side of the knee?

Fibula is on lateral side

What is the angle for coronals?

parallel to femoral condyles

What is the angle for sagittals?

perpendicular to femoral condyles

baker cysts

axial and sagittal

What is the superior/inferior coverage?

above patella including some of quad femoris tendon to the patellar ligament attachment on tibial tuberosity

If a patient has fluid collection do you open your FOV? Any exceptions?

No, don’t chase fluid.
Exception—> quadratis femoris tendon rupture

When do we run metal reduction scans?

when there’s hazrdware like screws and clips.

What protocol would we run for entire prosthetics?
Where can they be found?

SEMAC
Slice encoding for metal artefact correction
Only on Vidas

What would we run for metal in a knee?

MARS
Metal artefact reduction sequence

How to provide metal reduction (blooming and pileup artefacts)

Triple bandwidth
Increase an average
Reduce TE
Increase Turbo factor
Increase resolution and increase matrix size but keep voxels the same and lower slice thickness
Optimize phase encoding direction to be perpendicular to the metal because parallel causes more of a blooming artefact

VAT (View Angle Tilting) and WARP in scanner
Larger % of VAT will lower signal

If only have VAT 3x the bandwidth and 50% VAT

NO FAT SAT Sequences!!!!!
AX PD FS becomes a STIR

Ideal TR for PD and T2 FS weighted sequences?

Why?

3800+
It maintains an optimal signal of fluid and cartilage. Also helps with SAR.