Clinical utility, dose determination, and safety of ocular contrast‐enhanced ultrasonography in horses: A pilot study

Abstract

Objective To determine efficacy of contrast‐enhanced ultrasonography (CEUS) using different sulfur hexafluoride (SF6) doses to assess blood flow and perfusion in equine eyes and to evaluate safety of SF6 in horses. Procedures Ocular B‐mode and contrast‐enhanced ultrasonography were performed bilaterally in nine sedated university‐owned horses. Intravenous SonoVue® bolus injections of 5, 10, 15, 20, 25, and 30 mL were administered for 2/18, 5/18, 6/18, 3/18, 1/18, and 1/18 eyes, respectively. Doses were increased based on ascending bodyweight. Each eye within one horse was examined utilizing a different dose. Qualitative blood flow and quantitative perfusion were analyzed. Heart and respiratory rates were monitored nonsedated, sedated, and during first and second minutes of CEUS. Results Qualitative contrast enhancement (CE) was visible in 7/9 animals. Quantitative CE was measurable bilaterally in four horses, unilaterally in three individuals, and not detected in two animals. In all horses with unilateral CE, the positive eye received the higher dose. Fifteen mL dose resulted in significantly shorter time to peak than 10 mL (P < .05). Peak intensity, maximum signal increase, and corresponding area under the curve were significantly higher for 15 and 20 mL doses compared with 10 mL (P < .05). Uveal and retinal tissues were enhanced frequently. Twenty‐five and 30 mL doses revealed no CE. Only sedation reduced heart rates significantly (P < .05). Clinically relevant changes in respiratory rates or adverse reactions following SF6 application were not observed. Conclusions Contrast enhancement was in most instances dose‐dependent. Fifteen mL appeared appropriate to assess equine ocular perfusion. The reliability in horses remains questionable; however, CEUS was well‐tolerated.

Ultrasound-Based Technologies for the Evaluation of Testicles in the Dog: Keystones and Breakthroughs

“…In veterinary medicine, CEUS has primarily focused on dogs, especially in assessing the liver and its vascularization [ 116 , 127 , 128 , 129 , 130 , 131 , 132 ], lymph nodes [ 129 , 133 , 134 ], kidneys [ 135 , 136 ], pancreas [ 137 , 138 ], eyes [ 139 , 140 , 141 ], spleen [ 117 , 142 , 143 , 144 , 145 ], and prostate [ 146 , 147 , 148 , 149 , 150 ]. These studies have examined normal and pathological aspects, differentiating between inflammatory, degenerative, and neoplastic lesions, while providing discrimination between benign or malignant conditions [ 106 , 119 , 151 ].…”

Equine retinal detachment in the United Kingdom: 23 cases (2010–2020)

“…Techniques such as contrast‐enhanced ultrasonography has shown to be superior to B‐mode ultrasonography in humans and small animals in distinguishing retinal detachment from vitreal membranes (Han et al, 2001; Labruyere et al, 2011). However, preliminary work in horses has shown marked inter‐individual variation and poor reproducibility (Blohm et al, 2020). More work is needed to demonstrate the clinical utility of this technique in horses.…”