Radiographs:
- In the ventral thorax, a small accumulation of homogeneous soft tissue opaque material is identified and causes border effacement to the apex of the cardiac silhouette.
- Superimposed with the dorsal aspect of the caudodorsal lungs and mid thoracic vertebrae, there is a large, broad-based, and rounded soft tissue opacity (yellow arrows), with obtuse peripheral retraction of the lung lobe margins, representing an extra-pleural sign.
- In the cranioventral abdomen, likely within the large colon, there is a mild accumulation of granular mineral opaque material.
Conclusions:
- Caudodorsal extrapleural mass. In conjunction with the reported recent trauma, a hematoma is prioritized.
- Small amount of ventrally distributed pleural effusion, primarily raising concerns for a hemothorax.
- Small amount of sand in the large colon.
Ultrasound:
- An increased amount of mixed echogenic tissue/fluid is identified within the pleural space (hemothorax). In some locations, the material was homogenous and not moving. In the right pleural space, increased homogenous echogenicity is seen from ICS 9- ICS 14 (blood clot) with an increased amount of mixed echogenic fluid. The diaphragm was intact at all points. No excessive free abdominal fluid was seen. The right ribs were ultrasounded and appeared intact. The left thorax was normal with no evidence of pleural fluid.
- Thoracocentesis was performed over the 12th rib space, and 2 liters of hemorrhagic fluid were obtained, and sent in for analysis and culture.
Follow-up:
- Resolution of the hemothorax documented on a recheck visit. A small amount of effusion (modified transudate and fibrin) noted on ultrasound. No infectious organisms identified.
A little bit more…
- Hemothorax in horses is a condition where blood accumulates in the pleural cavity, often due to trauma or underlying disease (Sprayberry et al.).
- While radiographs are helpful for the identification of a hemothorax and evaluation of its extent, ultrasonography remains the most sensitive modality for the evaluation of pleural effusion. On radiographs, hemothorax typically appears as an increased opacity in the pleural space, which can obscure the lungs and margins of the cardiac silhouette (Sprayberry et al.).
- An extrapleural hematoma, which can mimic hemothorax, is characterized by the accumulation of blood between the parietal pleura and the endothoracic fascia. This sign is represented by the gradual inward displacement of the lung margins due to the presence of a fluid collection or mass (Chung et al.).
- Radiography may also be considered in trauma cases to screen for osseous injuries (e.g. rib fractures) and/or screen for signs of a diaphragmatic rent (Sprayberry et al.).
References:
- Chung JH, Carr RB, Stern EJ. Extrapleural hematomas: imaging appearance, classification, and clinical significance. Journal of Thoracic Imaging. 2011 Aug 1;26(3):218-23.
- Sprayberry KA, Barrett EJ. Thoracic trauma in horses. Veterinary Clinics: Equine Practice. 2015 Apr 1;31(1):199-219.
