Prolonged heterogeneous liver enhancement accompanied by abdominal symptoms after sonographic contrast agent injection: a cross-sectional study

Background: To report the occurrence of abdominal symptoms in patients who presented with prolonged heterogeneous liver enhancement (PHLE) after injecting contrast agent SonoVue((R)). Methods: A total of 105 patients who indicated to have contrast- enhanced ultrasound ( CEUS) examinations were consecutively observed. The liver scanning under ultrasound was performed before and after the contrast agent injection. Patients' basic information, clinical manifestations, and ultrasound images under B-mode and CEUS mode were respectively recorded. For patients exhibiting abdominal symptoms, the occurrence and last time of symptoms were recorded in detail. We subsequently compared the difference in clinical characteristics between patients with and without the PHLE phenomenon. Results: In 20 patients with the PHLE phenomenon, 13 showed abdominal symptoms. Eight patients (61.5%) appeared to have mild defecation sensation, and 5 (38.5%) showed apparent abdominal pain. The PHLE phenomenon began to appear within 15 minutes to 1.5 hours after the intravenous injection of SonoVue((R)). This phenomenon lasted for 30 minutes to 5 hours in ultrasound. Patients with severe abdominal symptoms showed large-area and diffuse PHLE patterns. Only sparse hyperechoic spots in the liver were detected in patients with mild discomfort. Abdominal discomfort resolved spontaneously in all patients. Meanwhile, the PHLE gradually disappeared without any medical treatment. In the PHLE-positive group, the proportion of patients with a history of gastrointestinal disease was significantly higher (P=0.02). Conclusions: Patients with the PHLE phenomenon can exhibit abdominal symptoms. We suggest gastrointestinal disorders may contribute to PHLE, which can be considered a harmless phenomenon that does not affect the safety profile of SonoVue((R)).