Contrast harmonic imaging of the normal canine spleen

The purpose of this study was to assess the perfusion pattern and perfusion dynamics in the normal canine spleen using contrast harmonic imaging. Twenty-five dogs without clinical or ultrasonographic evidence of splenic disease were studied. Twenty-three dogs were scanned with only manual restraint; two dogs were sedated with buprenorphin. All dogs received an intravenous bolus of a microbubble contrast medium (SonoVue). The perfusion pattern during the blood pool phase represented a skewed bell-shaped curve. A tissue-specific late phase, similar to humans, was not observed. Time/intensity curves were generated for a selected region. Mean average-derived peak intensity (PI) was 6.6dB, mean time to peak intensity calculated from the initial rise (TTP) was 25.6 s and mean area under the curve (AUC) was 523.6 dBs. If dogs were divided into two body weight groups (< or =15 and >15 kg body weight), average derived peak intensity area, time to peak intensity, and area under the curve were lower for the smaller dogs than for the larger animals. However, differences were not statistically significant (P = 0.2, 0.05, and 0.08, respectively). No significant association was found between hematocrit, hemoglobin concentration, red blood cell count, blood pressure, heart rate, age, gender, and the perfusion variables. In conclusion, these baseline data may prove useful in the evaluation of dogs with diffuse or focal splenic disease.