Equine Flashcards
According to the article ‘Abnormal imaging findings of femoral 3rd trochanter in 20 horses’ What do they recommend when a horse comes in for upper pelvic limb lameness?
Shields, G., ‘Abnormal imaging findings of femoral 3rd trochanter in 20 horses.’ VRU. Pre-published
Whenever a pelvic ultrasound is performed - ultrasound of the femoral trochanter should be performed as well.
What muscle groups attach at the 3rd trochanter of the femur?
Shields, G., ‘Abnormal imaging findings of femoral 3rd trochanter in 20 horses.’ VRU. Pre-published
Superficial gluteal muscles, and secondary site of insertion of the tensor fasciae latae
At recheck examinations of 3rd trochanter fractures - what did recheck US and Nuclear scintigraphy findings show?
Shields, G., ‘Abnormal imaging findings of femoral 3rd trochanter in 20 horses.’ VRU. Pre-published
US: Up to 3/4 had similar appearance (cranial displacement of fracture fragment) - likely due to the fracture healing by fibrous union.
Nuclear scintigraphy: mixed bag. Some had decreased IRU, some had increased IRU.
How did IRU of the third trochanter (due to fracture) relate to clinical lameness, duration of lameness and outcome?
Shields, G., ‘Abnormal imaging findings of femoral 3rd trochanter in 20 horses.’ VRU. Pre-published
Did not relate to degree of lameness, duration or outcome.
Describe the appearance of the starry sky hepatic pattern in horses
Starry sky hepatic US pattern in horses. VRU 52.5
numerous, small, hyperechoic foci (some of which cast an acoustic shadow), distributed randomly throughout all of the hepatic parenchyma
What was most common clinical sign in horses that were found to have a starry sky hepatic pattern on US?
Starry sky hepatic US pattern in horses. VRU 52.5
weight loss, anorexia
Was underlying liver dz common?
Starry sky hepatic US pattern in horses. VRU 52.5
9/18 horses had elevated liver enzymes
5/18 had primary liver dz
3/18 had severe dz
Believe that granulomas were not related to hepatic disease
What is the cause of the starry hepatic pattern on equine us?
Starry sky hepatic US pattern in horses. VRU 52.5
Granulomas
Also: fibrosis, eosinophilic inflammation or mineralization
ALL horses had granulomas at necropsy. Whereas, not all samples (36%) that were biopsied had granulomas present.
Why does the magic angle artifact occur?
Effect of DDFT orientation on MRI signal intensity in isolated equine limbs - the magic angle effect VRU 43.5
The angel at which the dipolar interaction between two nuclei is zero.
Dipole-dipole interactions will result in loss of T2 magnetization and loss of signal within a signal. Without interactions -signal will be increased.
How can the magic angle artifact be avoided?
Effect of DDFT orientation on MRI signal intensity in isolated equine limbs - the magic angle effect VRU 43.5
Using longer TE times (most common in
What is the equation of the magic angle artifact?
Which angle is the magic angle, what angles can this artifact be seen at?
Effect of DDFT orientation on MRI signal intensity in isolated equine limbs - the magic angle effect VRU 43.5
When 3 cos^2(angle)-1 = 0
54.74 (55)
Can be seen 50-60.
Which MR sequence is not affected by the magic angle artifact and why?
Characterization of the magic angle effect in the equine DDFT using a low-field MR system VRU 50.1
T2 (Long TE times)
Unlike in high field MR studies, in this study:
Characterization of the magic angle effect in the equine DDFT using a low-field MR system VRU 50.1
They found that there could be focal linear (rather than diffuse) effects associated with the dorsal vs palmar aspect of the DDFT in different areas of the tendon. Why is this?
Palmar aspect of DDFT have fibers that diverse from the middle phalanx to the navicular
Dorsal aspect of DDFT have fibers that diverge from navicular to insertion of impar ligament.
These fibers at these divergences are parallel to each other - if palmar aspect of DDFT is hyperintense proximally, then dorsal aspect of DDFT is hyperintense as well.
In this article:
Characterization of the magic angle effect in the equine DDFT using a low-field MR system VRU 50.1
What other ligament was affecte by the magic angle artifact?
Collateral ligaments of the DIP.
If there is hyperintensity of the collateral ligament, the DDFT should be evaluated palmar aspect of the DDFT on the same side (seen in all 12 cases)
What is the general shape of the DDFT in different areas?
Quantitative evaluation of equine DDFT morphology using MRI VRU 45.2
Distal to navicular bone - the DDFT is crescent shaped
At the navidular - the DDFT is more rounded
Proximal to the navicular bone - the DDFT is bilobed in appearance
