Role Of MRI In Estimating Local Tumor Regrowths After Interventional Therapy Of PHCC

Objective: Though the appearance of primary hepatocellular carci- noma(PHCC)treated with transcather arterial chemoembolization (TACE) or radio-frequency ablation(RFA) and local regrowths tumor on magnetic resonance(MR) images, to summarize the pattern of local regrowths tumor and to assess prospectively the optimization of T1WI,T2WI,DEC,DWI,to discuss Functional MRI Evaluation of distinguishing the local regrowths tumor of PHCC Treated with TACE and RFA。Methods: To analyses 74 patients of PHCC after TACE or RFA.The signal intensity of all lesions on SE T1WI,SE T2WI and the enhancement patterns on FMPSPGR dynamic contrast-enhanced scanning were observed,Diffusion-weighted imaging was examined in this study. With b value of 30 s/mm2, 300 s/mm2 ,600 s/mm2 and 1000 s/mm2, 22 lesions with local regrowths tumor, which were treated by TACE alone 7 lesions,RFA alone 1 lesions,combination of TACE and RFA 15 lesions. 2 enhance zone were transient hepatic parenchymal enhancement,10 circle enhance zone were inflammatory reaction. To analysize the MR images features of lesions with local regrowths tumor:such as size of the treated tumor, the pattern of local recurrence tumor, observed the signal on SE T1WI,SE T2WI,DCE,DWI to get the sensitivity of these sequence. Quantitative parameters were measured including arterial relative signal increase(ARSI,%), maximum relative signal increase(MRSI,%).ADC values b value of 30 s/mm2, 300 s/mm2,600s/mm2 and 1000 s/mm2were obtained and compared on delineated region of interested (ROI) using the functool 4.3 software system. The comparisons were made between the treated tumor versus local regrowths tumor,including RARSI, %,MRSI, %,ADC, The comparisons of ADC were made in different b values.The result data were analyzed with soft- ware (SPSS, version 11.5,P<0.05was considered to indicate a statistically significant difference.Results:(1)the MR findings of HCC treated by TACE or RFA were analyzed. the signal intensity was variant on T1WI and T2WI.(2)The pattern of local regrowths tumor including nodule regrowths,crescent-shaped regrowths,circle regrowths,irregular regrowths. 20 local regrowths tumor were hypointense on T1WI,21 local regrowths tumor were hyperintense on T2WI,18 local regrowths tumor were enhanced on DCE,4 local regrowths tumor were not enhanced. 10 circles regular thickening around the treated tumor,flow-up more than six months,the circles were inflammatory reaction. After TACE or RFA , 2 irregular area in the proximate of the treated tumor were transient hepatic parenchymal enhancement(3)DWI imaging more local regrowths tumor depicted on T1WI 90.91%,T2WI95.45%,DCE 81.82%,DWI 100%.(4)There was significant difference of ARSI(%) and MRSI(%) between the local regrowths tumor and the treated tumor,When b=1000s/mm2, there was significant difference of ADC value between local regrowths tumor and the treated tumor. The P value 0.02.Conclusion:(1)local regrowsths were definition as nodule or crescent-shaped areas at the margin of the treatment zone.the nodule regrowths was seen frequently. When the circle irregular thickening of one margin of the treated tumor,irregular area in the proximate of the treated tumor. hypointense on T1WI,hyperintense on T2WI,enhanced on early-phase dynamic scanning lesions,hyperintense on DWI maybe local regrowths.( 2 ) There was significant difference of ARSI(%) andMRSI(%) between the local regrowths tumor and the treated tumor .(3)DWI imaging depicted more local regrowths sensitivity, 100% than did T1WI sensitivity, 90.91%,T2WI95.45%,DCE 81.82%..DWI played an important role in evaluating the therapeutic after TACE and RFA. (4)When b=1000s/mm2, ADC values of local regrowths tumor and the treated tumor was significant difference.