Objective: To probe the relationship of clinical and pathological features of hepatocellular carcinoma (HCC) with the blood oxygen level by the technique of noninvasive magnetic resonance multi-echo R2*.
Methods: Multi-echo R2* sequence was carried out pre-operatively in a total of 46 patients with pathologically proved HCC. The T2* and R2* values of HCC, liver, spleen and paraspinous muscle on T2* and R2* maps and the ratios of HCC to liver (H/L), spleen (H/S) and muscle (H/M) were calculated. Different groups were defined according to such clinical parameters as the serum AFP level, lesion dimension, Edmondson's grade, ascites, capsula, liver cirrhosis, intrahepatic daughter foci or tumor-emboli in portal vein respectively. The differences in T2* and R2* values and the ratios between different groups were analyzed.
Results: In contrast with T2* value, the R2* value of HCC was less than that of liver or spleen (P < 0.05). Difference in R2* ratio of H/M (0.81 +/- 0.26 vs. 1.23 +/- 0.39) was found between positive and negative groups of AFP (P = 0.047, t = 2.248). And so was the same difference (0.83 +/- 0.24 vs. 1.23 +/- 0.43) between the lesions with or without capsula (P = 0.046, t = 2.257). The R2* ratio of H/S in hepatic cirrhosis group (1.01 +/- 0.58) was higher than that in noncirrhosis one (0.53 +/- 0.17) (P = 0.035, t = 2.247) whereas the T2* ratio of H/S was reversed (1.42 +/- 0.92 vs. 2.64 +/- 1.15) (P = 0.036, t = 2.230). The differences in T2* ratio of H/M in the group with or without intrahepatic daughter foci (1.18 +/- 0.47 vs. 2.24 +/- 1.71) (P = 0.048, t = 2.115), and in T2* value in the group with or without tumor-emboli in portal vein (27.24 +/- 11.90 ms vs. 46.70 +/- 38.40 ms) (P = 0.049, t = 2.046) were shown to be significant. However, no differences in MR parameters between other groups were observed (P > 0.05).
Conclusion: The blood oxygen level parameters, R2* and T2* values and the ratios are related to some clinical and pathological features of HCC. And the blood oxygen level is affected by multiple factors.