Incidence And Imaging Characteristics Of Benign Occupation Of The Liver In Patients With Chronic Hepatitis B

ObjectivesIn the first part,to analyze the incidence and risk factors of benign occupation of the liver(BOL)in patients with chronic hepatitis B(CHB).In the second part,to summarize the imaging features of BOL,including color doppler ultrasound,contrast-enhanced ultrasound(CEUS),dynamic contract-enhanced computed tomography(DCECT)and Gd-EOB-DTPA-enhanced magnetic resonance imaging(MRI),that differentiated these benign liver space-occupying lesions from hepatocellular carcinoma,as well as analyze the correlation of their manifestations between imaging and histopathology.So as to provide reference for the choice of imaging examinations that applied to the qualitative evaluation of the liver lesions found in the screening.In addition,to assist the clinical diagnosis and treatment of BOL with sufficient data,and provide a basis for differentiating benign liver lesions from the malignant ones by imaging pathway.MethodsWe retrospectively analyzed the imaging and clinical data of 17721 patients with CHB treated in the Hepatology Unit of Nanfang Hospital between January,2016 and December,2017.The data were compared with those of 21629 healthy control subjects undergoing routine physical examination in the Center of Heath Management of Nanfang Hospital during the same period.Then we described imaging features that differentiated benign space-occupying lesions from hepatocellular carcinoma,and explained them from the perspective of histopathology.ResultsCompared with the control subjects,the patients with CHB had significantly higher incidences of hepatic cysts(11.8%vs 8.7%,P<0.05),hepatic hemangioma(8.2%vs 1.6%,P<0.05)and hepatic cirrhosis nodules(20.6%vs 2.4%,P<0.05),as well as a lower incidence of focal nodular hyperplasia(FNH)(0.006%vs 0.042%,P<0.05).The incidences of hepatic cysts and cirrhosis nodules increased with age and was significantly higher in male than in female patients(P<0.05).The highest incidence of hepatic hemangioma was found in female CHB patients aged 30-49 years(P<0.05).BOL commonly showed regular shape and clear boundaries with homogeneous echo within the lesion sonographically,and "fast-in and slow-out" pattern in CEUS,DCECT and Gd-EOB-DTPA-enhanced MRI,which is different from malignant tumors.Liver cirrhosis nodules mostly showed a mixture of strong and weak echoes(81.1%;7944/9796)without blood flow signal within or around the nodule(91.2%;8933/9796)in ultrasonoscopy,while iso-or slight hyper-intensity with even enhancement in enhanced scan,and isointensity in Gd-EOB-DTPA-enhanced MRI.An increased volume of the nodule accompanied by heterogeneous echoes within the nodule indicated an increased probability of malignant lesion,as well as abnormal change of hemodynamics or contrast-enhanced examination.Hepatic hemangioma was distinctively hyperechoic in 77.8%(1821/2341)of the patients,presented with weaker peripheral and internal blood flow signals with a lower flow velocity in the arteries and a higher flow velocity in the portal vein,distinct from hepatocellular carcinoma.Hepatic cysts often displayed no echo within the lesion,but the echo could be enhanced posteriorly,easy to diagnose.FNH displayed characteristic fibroplasia(80.0%,8/10)and central scar(50.0%,5/10).hepatocellular adenoma(HCA)in large volume was showed as the boundary is not clear companied with steatosis,so that mixed hypo-and hyper-intensity was found on T1WI and hypointensity on fat-suppressed T2WI,as well as a decrease of signal intensity on opposed phase images compared with that on in-phase images in Gd-EOB-DTPA-enhanced MRI.HCA showed slight hypointense in the hepatobiliary phrase of Gd-EOB-DTPA-enhanced MRI,which could be differentiated from FNH(hyperintensity or "spoke-wheel" sign in the hepatobiliary phrase).Significantly different from the pattern of "fast-in and fast-out" in liver cancer,HCA mostly showed "fast-in and slow-out" in contrast-enhanced examination.ConclusionThe patients with CHB are at a significantly higher risk of developing hepatic cysts,hepatic hemangiomas and hepatic cirrhosis nodules than the control population,and an older age and the male gender are associated with a higher incidence of hepatic cysts or cirrhosis.For hepatic hemangioma,hepatic cyst and cirrhosis nodules,color doppler ultrasonography can be the first choice for screening,as well as FNH and HCA requires CEUS,DCECT or Gd-EOB-DTPA-enhanced MRI,even histopathological examination if necessary.The differences in imaging features can help to differentiate hepatic benign mass from malignant lesions at early stage,especially kinetic changes in sonography can be used to monitor potential malignant transformation of the cirrhotic lesions,which allowed a specific noninvasive diagnosis.