The influence of the hematocrit level in dogs and cats on the presentability and accuracy of the blood flow visualization

Purpose: It is to be assumed, that beside the parameters like angulation, velocity and vessel size the appearance of the ultrasound image is also influenced by the number of reflectors. If this hypothesis is true, the diagnostic evaluation might be influenced in anemic patients.

Materials and methods: The presentability and accuracy of the blood flow detection was analyzed on different flow phantoms also comparing CDI, PDI and B-Flow^®. The influence of the hematocrit level on the presentability and accuracy of the blood flow visualization was examined under standardized conditions. The flow phantoms consists of a plastic box, containing a tissue mimicking agent made of gelatin, starch and water and a silicone blood vessel imitation with a diameter of either 1 mm, 2 mm or 5 mm. Porcine blood was pumped through the vessel imitations at three different hematocrit levels (10%, 30% and 60%) and four different velocities (0.4 m/s, 0.8 m/s, 1.2 m/s and 1.4 m/s). The visualization was performed with a fixed M12L matrix linear transducer and a Logiq 9 (General Electrics). In order to evaluate the presentability of the vessels, a score system was created. The scores and the measured data were transferred into SPSS for Windows 11.5 and tested for normal distribution by Kolmogorov-Smirnov-test. Subsequently, the scores were checked for significance by Chi²-test and the acquired data were evaluated by Kruskal-Wallis-test or t-test, respectively.

Results: Hematocrit had no significant influence on presentability and accuracy of all methods.

Conclusions: Anemic or hypovolemic patients need no other settings than normovolemic patients to investigate the bloodflow.