The Value Of Gd-BOPTA Enhanced MR Imaging In Diagnosing Focal Liver Lesion

ObjectiveTo investigate the value of Gd-BOPTA on the diagnosis of focal liver lesion(FLL) with correlation to pathology.Materials and MethodsMRI scan was performed on 33 patients who were suspected of having FLL by CT or ultrasonography. The MRI scan protocol included routine axial T1WI and T2WI, coronal T2WI and 3D-MRCP, Gd-BOPTA enhanced fast gradient sequence of 3D-T1W (LAVA, GE company) in dynamic triphasic acquisitions(scanning at 15s,55s,90s), enhanced LAVA in delayed phase(at 5,10m) and in hepatobiliary phase(at 40m,80m), All patients were administered 0.01mmol/kg of Gd-BOPTA. Of the 42 lesions, 30 were confirmed by surgery, 3 is confirmed by biopsy. The lesions included 27 hepatocellular carcinoma(HCC), 5 focal nodule hyperplasia(FNH), 4 carvernous hemangioma, 4 hepatic metastasis and 2 acute infection. MRI findings of the lesions were analyzed with correlation to the pathological diagnosis. The diagnostic sensitivity and specificity of MRI were calculated. The difference of displaying lesions (including the number, the location, the size, the signal, the edage, the homogeneity)between routine MRI and LAVA were compared. The SNR and CNR of the lesions in all phases were calculated and compared.Results1. The sensitivity of this MRI protocol in detecting different FLLs were as follows: HCC 93.0%, FNH 83.3%, hemangioma 100%, metastasis 75%, acute infection 100%; The specificity of this MRI protocol in detecting different FLLs were as follows: HCC 92.0%, FNH 97.2%, hemangioma 97.4%, metastasis 97.4%, acute infection 100%;2. Routine+dynamic+hepatobiliary imaging improved displaying lesions more obviously than routine+plain+dynamic imaging: 19 vs 15 by markedly improved,16 vs 17 by medium improved, 5 vs 7 by slightly improved, 2 vs 3 by unchanged; The areas under the ROC curve of diagnosing HCC by routine+dynamic+hepatobiliary imaging, routine+dynamic imaging and routine imaging are respectively 0.948,0.895 and 0.673, there are significant difference between combined imaging and rountine imaging.3. The CNR in hepatobiliary phase(80m) and the pathology.①HCC:the CNR is -4.11±1.96, most of the lesions(23 lesions)showed homogeneous hypointense because of being short of normal hepatocyte's uptake, but 4 lesions (3 well-differentiated HCCs and 1 moderately differentiated HCC) showed inhomogeneous slightly hypointense blending with clouds or spot-like hyperintense parts, because of the cholestatic change in heteromorphism cell, cholangiole and phenomenon of excreting bile;②hemangioma and metastasis show slightly hypointense because of being short of normal hepatocyte's uptake, the CNR are -3.71±1.48 and -3.02±1.70;③Acute infection show isointense because of having normal hepatocyte infiltrated with inflammatory cells;④FNHs showed hyperor isointense in parenchyma because of having normal hepatocyte arranged by fibre and being short of portal tracts, the scar showed hypointense because of being short of normal hepatocyte and which were composed of thick-wall vessels, hyperplastic dile duct and inflammatory cells.ConclusionGd-BOPTA enhanced MRI have good sensitivity and specificity in diagnosing focal liver lesion, the combined phasic imaging (epecial combined with the hepatobiliary imaging) can improve detection of FLLs, and can reflect the pathological features of FLLs.