Fig 1.
Inclusion flow chart.
Table 1.
Characteristics of included patients.
Table 2.
Results of AUC analysis.
Fig 2.
ROC curve analysis for characterizing indeterminate focal liver lesions.
Fig 3.
Changes in the FLL categories when adding CEUS to MRI.
FLL = focal liver lesion, NRI = net reclassification improvement, Bp = probably benign, Bm = more likely benign, I = indeterminate, Mm = more likely malignant, Mp = probably malignant. (A) Reclassification table. In malignant FLLs, the NRI was calculated as (# up—# down) / # total. Therefore, NRI = (7–3) / 17 = 0.235. In benign FLLs, the NRI was calculated as (# down—# up) / # total. Therefore, NRI = (27–8) / 80 = 0.238. For all FLLs, the NRI was calculated as the NRI of malignant FLLs + the NRI of benign FLLs. Therefore, NRI = 0.235 + 0.238 = 0.473. (B) The Sankey diagram graphically depicts the changes in category between MRI alone and MRI + CEUS for FLLs. On adding CEUS, the number of FLLs in the indeterminate category decreased (22 FLLs on MRI and 10 FLLs on MRI+CEUS).
Fig 4.
Images in a 72-year-old man with an indeterminate focal liver lesion (arrows) on MRI.
An unenhanced MR image shows an irregularly shaped low-to-iso signal intensity lesion in liver segment 8 (A). The lesion shows subtle hyperenhancement on the arterial-phase (B), slightly low signal intensity on the transitional-phase (C), and low-to-iso signal intensity on the hepatobiliary-phase (D). On MRI, the lesion was categorized as indeterminate. Gray scale ultrasound image shows a relatively well-marginated low-echoic mass (E). The lesion shows arterial-phase hyperenhancement (F), late-onset washout (G), and defect on the Kupffer phase (H). On CEUS, it was categorized as probably malignant. The mass was surgically resected and confirmed as a hepatocellular carcinoma.