The CT scan characterized 15 lesions as typical HCC (hypervascular lesion with wash-out),
while 75 lesions were found to be atypical for CT examination (hypervascular without wash-out,
category 1A,
or hypovascular with wash- out,
category 1B).
EOB-MRI was able to identify a total of 73 lesions typed as HCC,
of which 21 lesions had not been detected by the CT scan.
EOB-MRI was able to categorize 56/75 (75%) of lesions with atypical behavior in CT.
Of the 75 lesions with atypical behavior in TC: 39/75 (52%) were categorized as HCC (category 2A,
2B,
2C); 7/75 (9%) remained uncertainty lesions; 17/75 (23%) were categorized as negative lesions for HCC; 12/75 (16%) were not evidenced.
Following a biopsy study on 11 lesions classified as HCC to MRI (2A,
2B,
2C) 9 (82%) of these were confirmed as HCC,
while the other 2 as regeneration nodules.
In the case of typical HCC (2A) 5/5 (100%) were confirmed; the agreement is also good in the case of hypovascular HCC (2C) 3/4 (75%).
The agreement was less good in hypervascular HCC without a wash-out (2B),
where a lesion of two was confirmed.
Typical lesions resulted bigger than atypical lesions (22.3±16.9 vs.
12.3±7.3 mm; p=0.0004) and in particular a lesion>15mm had a positive likelihood ratios (LR+) of 2.25 to be typical.
BCLC stage was changed after MRI in 61% (31/51) patients:
- "Up-staging" in 29/51 patients (57%);
- "Down-staging" in 2/51 patients (4%);
- Agreement in 20/51 patients (39%).
Based on MRI,
a biopsy was indicated for 7 nodules compared to 43 based on CT and 75% of group C lesions were confirmed histologically as HCC.