| Objective: The purpose of this study is to investigate the diagnosis and thedifferential diagnosis value of dynamic contrast enhancement MRI anddiffusion-weighted imaging between benign and malignant hepatic lesions.Materials and Methods: To collect the clinical and image data from the64cases ofliver focal lesions（92lesions） in patients from July2011to March2012,which wereconfirmed by surgery, biopsy, or clinical data to diagnose and follow up study. Lesiontypes, including17cases of hepatic cell carcinoma（HCC）（19lesions）,10cases ofmetastatic tumor （24lesions）,19cases of hepatic cavernous hemangioma（HCH）（23lesions）,18cases of liver cysts （26lesions）.Signa HDxt Twin Speed1.5T of GEcompany which is produced in USA were used in the study. Conventional MRI, liveracquisition with volume acceleration and diffusion-weighted imaging （DWI） wereperformed （b values0and500s/mm2respectively）in all patients. Signal characteristics ofdifferent lesions were analyzed in different sequence.Results were grouped into threemethods while analyzing the images. The values of detection and diagnosis of liverfocal lesions by T1WI,T2WI and enhanced multi-phasic LAVA scanning（methodA）,T1WI,T2WI and DWI（method B） and method A in combination with methodB（method C） were compared and analyzed. The apparent diffusion coefficient （ADC）values of all lesions were measured in the ADW4.4workstation. Statistical analysiswas applied to check whether the difference of mean ADC values between benign andmalignant focal lesions were statistically significant.Results:14lesions （14/19,73.7%）with hepatic cell carcinoma showed typically "Fast in and fast out " type to strengthen,19lesions （19/24,79.2%） metastases showed theedge of ring enhancement,18lesions （18/23,78.3%） with hemangiomas showed thetypical "infill" to strengthen, and26lesions of hepatic cysts（26/26,100%）dynamiccontrast-enhanced scan in all of phases were no strengthening. Mean ADC valueswere measured in liver cyst （3.25±0.19）×10-3mm2/s, hemangioma（2.19±0.78）×10-3mm2/s, metastatic tumor （1.21±0.33）×10-3mm2/s, hepatic cellcarcinoma （1.31±0.30）×10-3mm2/s. There was no statistical significance betweenmetastatic carcinoma and hepatocellular carcinoma（P＞0.05）. Other pairwisecomparisons were statistically significant（P<0.05）.In terms of lesion detection,92lesions （92/92,100%）were detected in all methods（A,B,C）.Compared to method A,method B, method C, no difference has been found in the detection rate of lesions; Interms of lesion diagnosis,77lesions （77/92,83.7%）were diagnosed properly inmethod A,66（66/92,71.7%） in method B, and85（85/92,92.4%） in method C.Differences of lesion diagnosis among the three methods were statistically significant.（χ2=13.77,p=0.001）.Conclusion: Liver acquisition with volume acceleration is able to clearly show thecharacteristic changes of the blood supply in the liver disease.The mean ADC valuesof benign tumors are higher than malignant, magnetic resonance dynamiccontrast-enhanced combined with diffusion-weighted imaging techniques scan canincrease the diagnostic information in hepatic focal lesions, improve the diagnosticaccuracy, the qualitative diagnosis has showed important clinical value. |
