Diagnosis Value Of Small Hepatocellular In Cirrhosis: Comparison Of Gd-BOPTA Enhanced MRI And Multiphasic Multirow Detector CT

Objective: To evaluate the diagnostic efficiency of Gd-BOPTA enhanced MRI using 3.0T and multiphasic multirow detector CT(MDCT)in detecting small(?30mm)hepatocellular carcinoma(SHCC)in patients with liver cirrhosis.Methods: A total of 19 patients(14 men,5 women;age range: 31-81 years)with 28 HCCS(?30mm in diameter)which confirmed by the pathological results were enrolled in this study..All patients with cirrhosis underwent both multiphasic(arterial,portal venous,equilibrium)MDCT and MRI which included routine MRI sequences and Gd-BOPTA enhanced MRI(early arterial,delay arterial,portal venous,equilibrium and hepatobiliary phase).Two observers reviewed the MR and CT images on a lesion-by-lesion basis independently and randomly.The signal strength,presence of psuedocapsule and mosaic pattern etc.were evaluated.The results were compared with pathology.The evaluation of CT images was completed at one time,while that of MRI was processed in two steps.At first,all of MRI sequence including routine and LAVA sequences were evaluated,and the result was defined as MRI1.Secondly,the patients order was disrupted and the LAVA sequence was evaluated and the result was defined as MRI2.The results of CT were compared with MRI1 and MRI2 respectively.The diagnostic efficiency of these techniques in detecting HCC was assessed by X2 analysis.For each lesion,the largest diameter was measured on the clearest image in horizontal axial(a),coronal(b)and sagittal positions(c).According to the spherical volume formula V=(4/3)?r3,the approximative formula V=abc/2 was got to calculate the lesion volume on CT and MRI respectively(those lesions which were not shown on CT were defined as 0).Variance analysis was got by using matching t-test.Results: 28 lesions were showed in 19 patients,with 22 lesions detected on CT and 28 lesions detected on MRI.The detection rate was 78.6% and 100%,respectively.16 lesions were showed on routine CT images,18 lesions were showed on both arterial and portal-phase CT images,22 lesions were showed on equilibrium-phase CT images which showed the advantage in detection among multiphasic CT scans.Among enhanced MRI scans,26 lesions appeared in delay arterial phase images which showed better detection than those in early arterial phase and equilibrium phase with 23 lesions in both phases.10 lesions with the typical enhancement pattern(arterial enhancement and washout during the portal/delayed phases)appeared on enhanced CT images and 15 lesions on MRI images.There were 5 lesions with psuedocapsule and 20 with mosaic pattern on MRI images.There were 8 lesions with psuedocapsule and 10 with mosaic pattern on CT images.After statistics analysis,CT and MRI1 was compared and P value is 0.008(P<0.05),which means the difference was statistically significant.CT and MRI2 was compared and P value is 0.039(P<0.05),which means the difference was statistically significant.The volume of 28 SHCCs were detected by both CT and MR were measured and the values were significantly(P <0.05).Conclusion: Multi-phasic MDCT showed a better detection than plain CT scan.There are many sequences in MRI,which can make up each other between different sequences,and improve the SHCC detection rate significantly.Especially with combinating with Gd-BOPTA enhanced sequence,the diagnostic accuracy for SHCC can be improved.