Correlation of radiographic measurements of structures of the equine foot with lesions detected on magnetic resonance imaging.

REASONS FOR PERFORMING STUDY: There are few studies on the correlations between radiographic measurements of the foot and abnormalities of specific structures found with magnetic resonance imaging (MRI). OBJECTIVES: To document the relationship between radiographic measurements of the equine foot and the presence of lesions in the foot on MRI. We hypothesised that different radiographic measurements would be associated with specific lesions detected by MRI. STUDY DESIGN: Retrospective analysis of radiographs and MRI studies. METHODS: Seventy-four feet from 52 lame horses were included. Twenty parameters were measured on radiographs, whereas the signal intensity, homogeneity and size of each structure in the foot were evaluated on magnetic resonance images. The data were analysed using simple linear correlation analysis and classification and regression trees (CARTs). RESULTS: Linear correlations were found between the navicular bone compacta thickness and injuries of the deep digital flexor tendon, collateral sesamoidean ligament, navicular spongiosa and navicular bone proximal border. Long-toed horses had a high incidence of lesions involving the spongiosa and proximal border of the navicular bone. Elongation of the navicular bone was associated with proximal and distal border injuries. A reduced palmar angle and increased angle between the middle and distal phalanx were observed in horses with alterations of collateral ligaments of the distal interphalangeal joint and navicular bone spongiosa, respectively. For each structure under investigation, CARTs predicting the presence of MRI pathology based on radiographic measurements had excellent performance, with >80% correct classification of cases, when using one of 3 data sources. CONCLUSIONS: This study demonstrated a relationship between radiographic measurements of the foot and the presence of lesions detected on MRI, while CARTs illustrated that different radiographic measurements were associated with different MRI lesions.

Intradural-extramedullary haemangioblastoma with paraspinal extension in a dog.

CASE REPORT: An 8-year-old spayed female cross-breed dog was evaluated following a 2-month history of thoracic limb weakness. Neurological examination revealed a spinal cord lesion between C1 and C5 segments. Magnetic resonance imaging (MRI) revealed that almost 70% of the spinal canal between C1 and C2 was occupied by an intradural extramedullary mass that was connected to a paraspinal mass from the cranial aspect of C2 to the cranial aspect of C3. The dog was anaesthetised and a dorsal, right-sided hemilaminectomy was performed. A durotomy was performed to expose a multilobular mass located principally along the right dorsal-lateral aspect of the spinal cord. The mass did not appear to infiltrate the cord parenchyma. The abnormal tissue was removed as completely as possible using gentle dissection and submitted for histological evaluation. The histological findings were consistent with an intradural-extramedullary haemangioblastoma with paraspinal extension. Following surgery, no neurological deterioration was detected. A metronomic-dosing chemotherapy protocol was administered to prevent progression or recurrence of the tumour. Follow-up MRI studies were performed 3, 6 and 12 months after the surgery, confirming complete tumour removal and the absence of recurrence. CONCLUSION: Haemangioblastoma is an extremely rare neoplasm in animals and only two cases of this tumour have been reported, but in other anatomical locations. Haemangioblastomas in human patients are more commonly located in the cerebellum and intradural-extramedullary growth is extremely rare. The dog in this study responded favourably to combined surgery and metronomic chemotherapy and was clinically normal 1 year after surgery.

Contracted foal syndrome associated with multiple malformations in two foals.

Congenital anomalies in horses are very rare, and contracted foal syndrome is one of the most commonly reported. This malformation is characterized by contraction of the joints of the forelimbs and/or hindlimbs. In addition, the syndrome can be characterized by vertebral column malformations, such as scoliosis or torticollis, and cranial deformity. The present report describes the radiological and necroscopical findings of multiple rare malformations in two foals. Both foals showed skeletal abnormalities and fenestration of the abdominal cavity. Other pathological findings include a interventricular septal defect in one and a unilateral hydronephrosis and partial hydroureter in the other foal. Although in this report a specific aetiology could not be provided, insecticides treatment provided during the second month of pregnancy might play a role in the pathogenesis of these malformations.

Segmental spinal cord hypoplasia in a Holstein Friesian calf.

An 8-day-old female Holstein Friesian calf was examined because of congenital spastic paresis of the hind limbs. Myelography revealed deviation and thinning of subarachnoid contrast medium columns in the lumbar segment. Upon magnetic resonance imaging, the 'hour-glass' subdural compression appeared as a T1-hypointense, T2-hyperintense ovoidal area suggestive of cerebral spinal fluid collection, compatible with hydrosyringomyelia. The calf was euthanized and the necropsy confirmed the diagnosis of segmental spinal cord hypoplasia of the lumbar tract associated to hydromyelic and syringomyelic cavities.

Topographic comparative study of paranasal sinuses in adult horses by computed tomography, sinuscopy, and sectional anatomy.

Clinical and radiographic investigations of paranasal sinuses in horses are difficult due to the complex anatomy of these regions, the lack of patognomonic symptoms, and the low sensitivity of conventional diagnostic techniques. The aim of this study was to produce an anatomical atlas to support computed tomography (CT) and sinuscopy of the paranasal sinuses of the adult horse. Transverse, sagittal, and dorsal CT images were acquired, and sinuscopy with both rigid and flexible endoscopes was performed. The heads were frozen and sectioned using a band saw, with the cuts aligned as close as possible with the CT transverse slices. Each CT image was compared with its corresponding anatomical section and sinuscopy image to assist in the accurate identification of specific structures.

Tenoscopy of the navicular bursa: a new therapeutic approach for horses affected by "palmar pain syndrome." Endoscopic technique review and personal experiences.

Tenoscopy of the navicular bursa has been recently introduced as a diagnostic and therapeutic treatment in cases of palmar foot pain syndrome. A deep digital flexor tendon transthecal approach was suggested in 1999, and the endoscopic technique has been reviewed. Smith and coworkers have recently reported good and promising results. An anatomic cadaver limb study was performed, and the endoscopic technique was evaluated. Subsequently, a 14-year-old Argentine mare, affected by palmar foot pain syndrome, was treated. Clinical data, MRI and endoscopic findings, and a 6-month follow-up evaluation are reported.