Equine Diagnostic Ultrasound 2

sihirlifil's version from 2017-12-06 15:59

Synovial structures: Joints, tendon sheaths, bursae

Question Answer
Things to assess with synovial structuresSynovial fluid: amount & echogenicity
Synovia: proliferation, thickening
Articular surface, cartilage, subchondral bone (OC)
Joint capsule, sheath, wall of bursa
Collateral ligaments, menisci (stifle & TMJ)
(can do fluid sampling & intra-articular injections)
Normal synovial fluid looks like?Anechoic!
Technique for joints/tendon sheaths/bursaePrepare skin over entire joint area
Use highest frequency possible & smallest displayed depth: 7.5MHz, ideally >10MHz
Choose transducer & frequency according to joint location
Scan joint/synovial structure in its long & short axis
How should a normal joint look?Thin synovial membrane with villi/fronds
Thicker echogenic joint capsule
Anechoic joint fluid
Collateral ligaments: homogenous echogenicity, densely packed fiber bundles
+/- meniscus
Structures of the stifle joint (7)Patellar ligaments: Lateral, middle, medial
Long digital extensor/peroneus tertius
Medial & lateral collateral ligaments (lateral separated from meniscus by popliteal tendon)
Femoropatellar & femorotibial joint
Meniscotibial & meniscofemoral ligaments (caudal)
Cranial cruciate ligament (tibial attachment) & Caudal cruciate (femoral attachment)
(Normal stifle images)Top: Middle patellar ligament: proximal end on patella, distal on tibia
Bottom left: cross-sectional image
Stifle joint: what is @? **? ^?
@ = Femoral part (round)
^ = Proximal tibia (plateau)
** = medial meniscus bridging the space between
Stifle joint: red lines?
Origin of popliteus tendon (lateral) (more difficult to image lateral side)
Stifle joint: what is ***? which structures?
*** = Articular cartilage (anechoic!)
Can see femoral condyles. Big = medial, smaller = lateral
Stifle joint: calipers indicate?
Abnormal thickening of synovial lining/joint capsule
Abnormal joint: echogenicity of acute? chronic?Acute: Hyperechoic (hemorrhage, edema)
Chronic: hyperechoic (fibrosis)
Aside from thickening of synovial lining & joint capsule, what other signs of abnormal joint?Synovial cyst/ganglion: rupture of joint capsule & periarticular accumulation of synovial fluid
Cartilage defect
OCD lesions, fracture fragments (intra or extra articular) +/- mobility of fragments
What abnormality indicated by blue arrow? structures at red & green?
Blue: thickened wall of MTP joint
Green: synovial fluid in MTP joint
Red: suspensory ligament
Normal lateral pouch of stifle:
Dorsal transverse scans at the level of the tarsocrural (tibiotarsal) joint: what’s going on?
Chronic synovitis (abnormal content)
Thickened joint capsule, hypertrophied synovia, increased echogenic material
See more tissue than fluid- very little fluid for overall space of joint
What’s going on with these transverse & longitudinal images of the palmar pastern (distal to point of fetlock)?
Digital sheath effusion
** = Abnormal amount of anechoic fluid in tendon sheath
1 = DDFT
2 = Straight distal sesamoidean ligament
Longitudinal & transverse of M. flexor digitalis medialis: Green lines? red?
Green: Abnormal distension & content
Red: tendon
Distension & abnormally echogenic material in tendon sheath

Pelvis, Bones, OC, Muscles

Question Answer
Technique for imaging pelvisClip both sides to allow comparison between L & R
Assess muscles & bony surfaces
Linear or sector transducer
Deeper structures (ilial wing): lower frequency ~5MHz
Structures that can be evaluatedTuber sacrale
Spinous processes of sacrum
Ilial wings
Ischium (caudal part)
Coxofemoral joint
Scan of ilium through gluteal musculature: Sustained fracture of R ilial wing
Fragments with dorsal displacement
Horse presents with asymmetry in contour of gluteals (swelling on R side)
Periosteal reaction of the distal radius
Normal cortex smooth & even, periosteal reaction irregular
Can maybe see if discharging sinus (fluid accumulating, tap, see if need to tx infxn)
Trochlea of femur, longitudinal
Indentation in subchondral bone (not as hypoechoic) & echogenic fragment
Trochlea of femur, transverse. problem?
Indentation in subchondral bone
Lateral trochlea of stifle: arrows?
Subchondral lesions & OC fragments in joint (can pick up on US!)
Hyperechoic muscle fibers = fibrosis of M. semimembranosus
Compare to normal, homogenous:

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