To analyze the contrast-enhanced ultrasound (CEUS) findings of hepatic inflammatory pseudotumors (IPTs), and to assess their diagnostic value.

From December 2012 to December 2022, the clinical and contrast-enhanced ultrasound data of 76 patients with pathologically confirmed hepatic IPTs at Nanjing Drum Tower Hospital and Shanghai Zhongshan Hospital were retrospectively analyzed. The characteristics of conventional ultrasound (US) and contrast-enhanced ultrasound were summarized and their diagnostic accuracy was evaluated.

Five enhancement patterns were observed in 76 liver nodules: homogeneous enhancement (n=21, 27.63%), heterogeneous enhancement (n=20, 26.32%), rim-like enhancement (n=20, 26.32%), honeycomb enhancement (n=11, 14.47%), and no enhancement during vascular phases (n=4, 5.26%). The degree of enhancement was hyper-enhancement in 45 cases, iso-enhancement in 22, hypo-enhancement in 5, and no enhancement in 4. The number of nodules that were hypoechoic, mixed, isoechoic, and anechoic in the portal and delayed phases was 55, 15, 2, and 4, respectively. The median initial enhancement time, time to peak, and wash-out time were 15.0 (13.0, 19.3) s, 22.0 (19.8, 26.3) s, and 35.0 (30.0, 50.0) s, respectively. Fifty-six nodules (73.68%) were hypoechoic within 60 s after contrast medium injection, showing a "quick wash-in and wash-out" pattern, and 45 nodules were hypoechoic within 45 s. Based on ultrasonography, clinical findings, and laboratory examination, 48 nodules (63.16%) were correctly diagnosed as IPTs, while the remaining 28 cases were misdiagnosed as malignancy (n=23, 30.26%) or had an uncertain diagnosis (n=5, 6.58%).

Hepatic IPTs show various enhancement patterns due to pathological changes during the progression of the disease. The features of CEUS have appreciated value in the diagnosis of IPT, and the combination of clinical manifestations and laboratory examination helps to improve the diagnosis coincidence rate.