Diagnostic value of contrast-enhanced ultrasound for the maximum diameter ≤2 cm metastatic liver cancer: compared with contrast-enhanced CT

Objective To compare the diagnostic performance of contrast-enhanced ultrasound (CEUS) with contrast-enhanced computed tomography (CECT) for the maximum diameter ≤2 cm metastatic liver cancer (MLC). Methods Sixty-nine pathologically diagnosed MLC patients (maximum diameter ≤2 cm) were retrospectively recruited. The lesion detection rate, diagnostic confidence and enhancement pattern of CEUS and CECT for MLC were analyzed. Diagnostic value of CEUS and CECT for MLC were evaluated and compared by using diagnostic test. Results The cases of 0, 1, 2, multiple lesions detected by CEUS and CECT in these 69 patients with ≤2 cm MLC were 0 case (0%), 41 cases(59.42%), 13 cases(18.84%), 15 cases(21.74%) and 9 cases(13.04%), 29 cases(42.03%), 13 cases(18.84%), 18 cases(26.09%), respectively. The positive cases detected by CEUS and CECT were 69 cases(100%) and 60 cases(86.96%) respectively, with a statistically significant difference between the two groups (P=0.006). However, for the detection rate of non-single-lesion cases, there was no statistical difference between CEUS and CECT (P=0.409). The cases showed typical manifestation in CEUS and CECT were 56 cases(81.16%)and 29 cases(42.03%)(P<0.001). The cases with diagnostic confidence level of 3, 4, 5 in CEUS were 3 cases(0.04%), 11 cases(15.94%), 55 cases(79.71%), and those of CECT were 19 cases(27.54%), 20 cases(28.99%), 20 cases(28.99%), respectively. The diagnostic sensitivity of CEUS and CECT for ≤2 cm MLC were 100% (69/69) and 85.51% (59/69), with statistically significant difference(P=0.001). Conclusions The lesion detection rate and diagnostic value of CEUS for the maximum diameter ≤2 cm MLC might be superior to that of CECT, but the detection rate shows no significant difference in the non-single-lesion cases. CEUS has important clinical value in the diagnosis of ≤2 cm MLC. Key words: Contrast-enhanced ultrasound; Metastatic liver cancer; Contrast-enhanced CT