Values of spectral CT imaging in differential diagnosis of hepatocellular carcinoma and focal nodular hyperplasia

Abstract

Objective To explore the application value of spectral CT multi-parameter imaging in the differential diagnosis of hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH). Methods Forty-eight patients with hepatic lesions underwent gemstone spectral imaging (GSI) scans,including 32 HCC and 16 FNH,to obtain spectral serial images for the arterial phase and portal venous phase (PVP).The spectral parameters of lesions,normal hepatic tissue and the aorta were measured.Then,the lesion-liver contrast-to-noise ratio (CNR) in the different energy levels,normalized iodine concentration (NIC),the lesion-normal parenchyma iodine concentration ratio (LNR) and iodine concentration difference (ICD) between the arterial phase and the portal venous phase were calculated.The above measurement results were analyzed with two samples t test and ROC curve. Results The CNR of HCC and FNH in the different energy levels showed a certain regularity.In general,with the single photon energy increased,the CNR decreased except for some energy points.For HCC and FNH,the optimal CNR were 3.59±2.13 and 8.29±2.65,respectively,during the arterial phase and 1.80±0.42 and 1.06±0.34,respectively,during the portal venous phase.The NIC were 0.25±0.08 and 0.42±0.22,respectively,during the arterial phase and 0.52±0.14 and 0.86±0.18,respectively,during the portal venous phase.The LNR were 2.97±0.50 and 6.15±0.97,respectively,during the arterial phase and 0.99±0.19 and 1.22±0.26,respectively, during the portal venous phase.The ICD were (0.35±0.14) and (1.17±0.28) g/L,respectively.The NIC,LNR and ICD for HCC were less than FNH during the arterial phase and the portal venous phase.There were significant differences in NIC (t=-3.196,the arterial phase;t=-6.518,the portal venous phase),LNR (t=-12.911,the arterial phase; t=-3.260,the portal venous phase),and ICD (t=-2.754) between HCC and FNH (P<0.05).LNR in the arterial phase had the highest sensitivity and specificity of 100% and 100% in differentiating HCC from FNH. Conclusion The use of spectral CT with the quantitative analysis of iodine concentration might be helpful for increasing the efficiency of the detection and accuracy of diagnosis of HCC and FNH. Key words: Liver neoplasms; Tomography,X-ray computed; Diagnosis,differential