Normal liver-to-heart transit time and shunt fraction after transplenic injection of 99MTC-pertechnetate in healthy cats

Portosystemic shunts (PSS) are rare vascular anomalies in cats. Transsplenic portal scintigraphy (TSPS) can aid in diagnosing PSS in cats. Although the actual performance of the scan remains the same between species, it is questionable whether the generally accepted transit time of seven seconds for small dogs can be applied to cats, thereby influencing shunt fraction (SF) calculation. In this study, normal mean transit time and SF were determined in a population of cats without PSS following two methods established in canine medicine. For both, the mean ± SD transit time was calculated as 6.75 ± 1.58 seconds and 7.40 ± 1.64 seconds respectively, without significant difference between both methods. The results confirmed the validity of the generally used transit time of seven seconds for SF calculation in cats. The average normal SF (± SD) for the cats in this study was 0.73 % (±0.74; range 0.11-2.48%).