Imaging diagnosis-aortic aneurysm and ureteral obstruction secondary to umbilical artery abscessation in a 5-week-old foal

Development of a three-dimensional computer model of the equine heart using a polyurethane casting technique and in vivo contrast-enhanced computed tomography

INTRODUCTION/OBJECTIVES

Insight into the three-dimensional (3D) anatomy of the equine heart is essential in veterinary education and to develop minimally invasive intracardiac procedures. The aim was to create a 3D computer model simulating the in vivo anatomy of the adult equine heart.

ANIMALS

Ten horses and five ponies.

MATERIALS AND METHODS

Ten horses, euthanized for non-cardiovascular reasons, were used for in situ cardiac casting with polyurethane foam and subsequent computed tomography (CT) of the excised heart. In five anaesthetized ponies, a contrast-enhanced electrocardiogram-gated CT protocol was optimized to image the entire heart. Dedicated image processing software was used to create 3D models of all CT scans derived from both methods. Resulting models were compared regarding relative proportions, detail and ease of segmentation.

RESULTS

The casting protocol produced high detail, but compliant structures such as the pulmonary trunk were disproportionally expanded by the foam. Optimization of the contrast-enhanced CT protocol, especially adding a delayed phase for visualization of the cardiac veins, resulted in sufficiently detailed CT images to create an anatomically correct 3D model of the pony heart. Rescaling was needed to obtain a horse-sized model.

CONCLUSIONS

Three-dimensional computer models based on contrast-enhanced CT images appeared superior to those based on casted hearts to represent the in vivo situation and are preferred to obtain an anatomically correct heart model useful for education, client communication and research purposes. Scaling was, however, necessary to obtain an approximation of an adult horse heart as cardiac CT imaging is restricted by thoracic size.

Discolored Urine in Horses and Foals

This article describes the most common causes of urine discoloration. The review includes a description of the most common disorders causing hematuria, highlighting clinical presentation, treatments, and pathophysiology. Causes of hemoglobinuria and myoglobinuria together with their mechanisms of renal injury are also reviewed.

Imaging of the Urinary Tract

This article provides a comprehensive review of imaging techniques used to evaluate the equine urinary tract. This overview includes officially recognized modalities and new applications reported in the most current literature. Technical aspects and indications for use of endoscopy and ultrasonography are highlighted. Normal endoscopic and ultrasonographic appearance of the upper and lower urinary tract is described, with characterization of common abnormalities found in patients with hematuria, stranguria, and renal failure. Visual examples of several pathologic conditions from clinical cases are provided. An outline of the main features, potentials, and limitations of radiography, nuclear scintigraphy, and computed tomography is provided.

Clinical, ultrasonographic, and postmortem findings in sheep and goats with urinary tract disorders

Background and Aim:

In sheep and goats, most urinary disorders are incidental findings at the postmortem examination and do not present clinically. As such, the diagnosis of renal diseases in sheep and goats can be overlooked. Therefore, this study was carried out on sheep and goats to describe the clinical, ultrasonography(USG), and postmortem findings of various disorders affecting the urinary tract.

Materials and Methods:

A total of 58 animals (30 sheep and 28 goats) were examined, as well as were ten healthy control animals (five sheep and five goats) for a comparison. The animals were referred for various causes, including anorexia, frequent and painful urination, hematuria, decreased body weight, oliguria, and anuria.

Results:

The sheep and goats were categorized into ten groups of symptoms and disorders: Pelvic abscessation, pigmented urine, renal failure, pyelonephritis, cystitis, hydronephrosis, rupture of the urethra, rupture of the urinary bladder, rupture of the urinary bladder together with the urethra, and paralysis of the urinary bladder. Clinical presentation, USG, and postmortem examination results for each group were detailed. Many clinical presentations were nonspecific. USG examination of the urinary tract significantly facilitated the verification of the previously mentioned disorders.

Conclusion:

USG demonstrated superior performance in the early and confirmatory diagnosis of urinary disorders in sheep and goats. Therefore, it is recommended that routine USG be the preferred imaging modality for examining sheep and goats with urinary disorders and for determining their prognosis.

Diagnosis of a sublaryngeal abscess in a Japanese Black calf using computed tomography

A 76-day-old Japanese Black calf presented with severe stridor, resenting palpation of the laryngeal region. Endoscopic examination revealed an expansile process restricting the esophageal and tracheal lumina caudal to the arytenoid cartilage, hyperemia and edema of the pharyngeal mucosa, right arytenoid cartilage swelling and displacement, and marked airway obstruction. The absence of an endotracheal wall abnormality impeded a definitive diagnosis. Computed tomography (CT) revealed a mass (CT value: 40–45 HU) caudal to the arytenoid cartilage, causing tracheal stenosis and esophageal displacement. The presence of gas in the mass suggested the presence of an abscess. Diagnosis of deep retropharyngeal lesions by conventional endoscopic and ultrasonographic examinations may be challenging; CT can then provide more comprehensive diagnostic information on a lesion.

Experimental investigation of bone mineral density in Thoroughbreds using quantitative computed tomography

Bone mineral density (BMD) is one of the indications of the strength and health. BMD measured by quantitative computed tomography (QCT) was compared with that measured by dual energy X-ray absorptiometry (DXA) and radiographic bone aluminum equivalence (RBAE). Limbs were removed from horses that had been euthanized for reasons not associated with this study. Sixteen limbs (left and right metacarpals and metatarsals) from 4 horses were used to compare BMD as measured by QCT with those measured by DXA and RBAE. There was a strong correlation between BMD values measured by QCT and those measured by DXA (R(2)=0.85); correlation was also observed between values obtained by QCT and those obtained by RBAE (R(2)=0.61). To investigate changes in BMD with age, 37 right metacarpal bones, including 7 from horses euthanized because of fracture were examined by QCT. The BMD value of samples from horses dramatically increased until 2 years of age and then plateaued, a pattern similar to the growth curve. The BMD values of bone samples from horses euthanized because of fracture were within the population range, and samples of morbid fracture were not included. The relationship between BMD and age provides a reference for further quantitative studies of bone development and remodeling. Quantitative measurement of BMD using QCT may have great potential for the evaluation of bone biology for breeding and rearing management.

Diagnostic imaging of intra-abdominal cyst in heifer using the computed tomography

A 10-month-old Japanese black heifer was diagnosed as having an intra-abdominal cyst using computed tomography (CT). Through a posterior ventral midline incision, the cyst was removed, and the heifer completely recovered after the surgery. CT scans enabled detection of the intra-abdominal cyst and measurements of the diameter of the cyst before the surgery.