| Objective:To explore the value of intravoxel incoherent motion?IVIM?including biexponential model and stretched-exponential model in differential diagnosis of hepatic abscess and cystic necrosis hepatic malignant tumor.Method and Materials:All patients who performed liver scanning on a 1.5 Tesla MR system?Signa HDxt;GE Healthcare;USA?were retrospectively collected?n=36 patients?from our hospital from September 2015 to October 2017.Seventeen of 36 patients were confirmed as hepatic abscess,seven of which were proven by percutaneous aspiration and others by clinical diagnosis.The others were confirmed as hepatic malignant tumor,five of which were proven by surgical resection and others by clinical dignosis.The liver MR protocol included DWI?b value=600 s/mm2?and eDWI with 10 b values?b values=20,50,100,150,200,400,800,1200,2000,3000 s/mm2?sequences.With sending DWI and eDWI sequences to GE AW4.6 workstation and using software of ADC and eADC to reconstruct images,DWI sequence and eDWI sequence were respectively reconstructed maps of ADC,standard ADC,Dmono,D*mono,fmono,Dbi,D*bi,fbi,DDC and?.One ROI?region of interest?that was account for 50-66%of the cavity was set in the cavity on the DWI and eDWI images and two ROIs were on the wall,the value of ADC and standard ADC were acquired.Then two ROIs were set on the wall of eDWI sequence,the value of Dmono,D*mono,fmono,Dbi,D*bi,fbi,DDC and?were acquired.The intraclass correlation coefficient?ICC?was executed to analyze inter-observer consistency of the two radiologists for measurements.The senior doctor's data was performed for next step when value of ICC was greater than six.The datas were performed by student's t-test to contrast parametric values in two groups,which also obeys normal distribution.The other datas were performed by Mann-Whitney test to contrast parametric values in two groups.Diagnostic performance was evaluated with the receiver operating characteristic?ROC?curve analysis.Results:The ICC value of the ADC and standard ADC of cavity and wall in hepatic abscess group were respectively 0.997,0.948 and 0.912,0.858.The ICC value of the ADC and standard ADC of cavity and wall in cystic necrosis hepatic malignant tumor group were respectively 0.904,0.994 and 0.967,0.982.The ICC value of Dmono,D*mono,fmono,Dbi,D*bi,fbi,DDC,?of the wall in hepatic abscess group were respectively0.98,0.781,0.917,0.684,0.912,0.932,0.797,0.955.The ICC value of Dmono,D*mono,fmono,Dbi,D*bi,fbi,DDC,?of the wall in cystic necrosis hepatic malignant tumor group were respectively 0.953,0.856,0.961,0.693,0.779,0.944,0.943,0.869.In two groups,the ADC value of cavity were respectively?1.41±0.47?×10-3mm2/s and?2.29±0.54?×10-3mm2/s,the ADC value of wall were respectively?1.57±0.29?×10-3mm2/s and?1.29±0.28?×10-3mm2/s;the standard ADC value of cavity were respectively?1.12±0.34?×10-3mm2/s and?1.48±0.29?×10-3mm2/s,the standard ADC value of wall were respectively?1.05±0.15?×10-3mm2/s and?0.88±0.19?×10-3mm2/s;the fmono value of wall were respectively?0.59±0.15?and?0.42±0.17?;the Dbii value of wall were respectively?1.25±1.06?×10-3mm2/s and?0.64±0.20?×10-3mm2/s;the DDC value of wall were respectively?2.06±0.78?×10-3mm2/s vs?1.20±0.48?×10-3mm2/s,the results were statistically significant?p<0.05?.The area under the ROC curve of cavity of ADC and standard ADC were respectively 0.897 and 0.764.The area under the ROC curve of wall of ADC and standard ADC were respectively 0.811 and 0.753.The area under the ROC curve of wall of fmono,Dbi and DDC were respectively 0.789,0.703 and 0.881.Conclusion:Same diagnostic efficiency of standard ADC and ADC value in differentiating hepatic abscess from cystic necrotic hepatic malignant tumor was observed.The fmono,Dbi and DDC value have statistical significance and may be useful for differentiating pyogenic hepatic abscesses and cystic necrotic hepatic malignant tumor. |
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