Read how EqueTom positively impacted the diagnosis and intervention for 3/5 left forelimb lameness on Dubay, male horse, 23-years old
Dubay, Horse Male
Age: 23 years-old
Breed: Crossed breed
Dubay had an accident in the stable which was trapped against the wall of the box. When the grooms took him out of the box, the horse walking in straight line had 3/5 left forelimb lameness (AAEP lameness scale). When struggling to get out of that situation, he sustained multiple injuries over the palmar area of the metacarpal region of his left forelimb. The palmar aspect of the left forelimb was totally swollen so it was decided to proceed with the radiographic examination for suspicion of a fracture. Ultrasonographic examination was not possible at this moment due to the great inflammation which could lead us to a wrong diagnosis.
Initial scan images
The approach taken are the four initial standard radiographic views, (latero-medial, dorso-palmar, dorsolateral- palmaromedial oblique, and dorsomedial- palmarolateral oblique), of the left metacarpal bone was performed to decide if further radiography is required. In most cases with these views it is possible to identify bony abnormalities, e.g., displaced fractures. Lesion orientated projections or small increments of 5 degrees can be performed to assess the whole lesion before referring the horse for further assessment. After this procedure a periosteal reaction on the middle-low third of the fourth metacarpal bone was found.
EqueTom scan images
Four days later we performed the procedure with the EqueTom™ linear digital tomosynthesis unit.
It was decided to perform a latero-medial view of the left metacarpal area. It was possible to observe periosteal reaction, several fissures of the fourth metacarpal bone, and new bone formation due to the traumatic concussion. Sequences of the tomosynthesis procedure showed below.
Slice sequences latero-medial view EqueTom™ linear digital tomosynthesis unit.
Conclusion and treatment.
One of the greatest advantages of the EqueTom™ unit is that we only need to do one projection to fully evaluated the metacarpal bone compared with the four projections needed with the normal digital radiographic procedure. Since we only need the one projection stated, there is a reduction in radiation exposure to the patient and the personnel involved the diagnostic imaging procedure. When talking about human medicine, reducing radiation doses comes from a correct optimization of the DR systems.
Radiation dose should be as low as reasonable achievable (ALARA) and obtain image quality as good as possible to achieve an accurate diagnosis. In the present case report, the total number of radiographic abnormalities counted on the EqueTom™ unit was much higher that the digital radiography system which indicate that radiography has less sensitivity and specificity in detecting abnormal findings of the metacarpal bone than the EqueTom™ system. The difference between the one projection of the EqueTom™ system and the four of the digital radiography system permitted a higher visualization of the metacarpal bone indicating better visibility of pathological findings. Pathological changes that were ill defined or indetectable on radiography could be visualized on the EqueTom™ images.
These ill-defined changes could be detected on the DT system due to the computed tomography properties were lack of superimposition of the surrounding structures and the high sensitivity for detecting bone in detail. If we only performed the radiographic procedure, our definitive diagnosis would have been periosteal reaction of the fourth metacarpal bone whereas with the EqueTom™ system we could detect several fissures and new bone formation. The fissures could lead to the slow onset of healing and soundness of the horse, and the new bone formation could lead to impingement of the suspensory ligament. Given the presence of active bon, a period of 6-12 weeks of rest was recommended with box rest with bandages. NSAIDS, phenylbutazone (4.4 mg/kg, q 12 h, 5 days), where given due to the quick and short period of time providing good analgesic properties and anti-inflammatory response. Centesis of the metacarpal bone with corticosteroids, 16mg triamcinolone acetonide (Trigon Depot), has been shown to be more beneficial for the treatment to stop the new bone formation.