Evaluation Of Short-Term Therapeutic Efficacy Of HIFU In Primary Hepatic Carcinoma Combining DWI With DCE-MRI

Objectives: To study the value of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MRI (DCE-MRI) in evaluating the short time efficacy of high intensity focused ultrasound (HIFU) for primary hepatic carcinoma (PHC).Materials and Methods: Thirty-nine leasions in twenty-seven patients with clinical or pathological confirmation of PHC accepted HIFU treatment and underwent DWI, plain and dynamic contrast-enhanced MRI scanning at 1.5T MRI within one week before HIFU and one week, three monthes after HIFU. The measurement of mean apparent diffusion coeffecient (ADC) values was performed. According to the signal characteristics of T2WI, DCE-T1WI and DWI and the changes of mean ADC values of the tumor necrosis, recurrence and survival oncosis, the thirty-nine lesions were divided into stable group (n=28) , recurrent group (n=7) and survival group (n=4).Results: Twenty-eight lesions (28/39, 71.8%) showed uneven low signal in T2WI, no significant strengthening in DCE-MRI and low signal in DWI within one week after HIFU and no significant changes were detected in the follow-up MRI after three monthes. Seven lesions (7/39, 17.9%) demonstrated uneven low signal in T2WI, no enhancement in the central areas and the peripheral annular enhancement in DCE-MRI but high signal in DWI within one week after treatment. Three monthes later, the nodulars of high singal within lesions and (or) the surrounding tissues were detected by T2WI. The corresponding region significantly strengthened in DCE-MRI and showed high signal in DWI. The viable nodulars within four lesions (4/39, 10.3%) and (or) the surrounding areas were detected by T2WI which significantly strengthened in DCE-MRI and showed high signal in DWI within one week after treatment and the survival tumor lesions increased in size after three monthes. The mean ADC values of stable group within one week after treatment were significantly greater than that of one week before treatment (p<0.05) . The mean ADC values in one week and three monthes after HIFU had no significant difference(p>0.05). Although the mean ADC values of recurrent group within one week after treatment had no statistical difference compared with one week before treatment (p>0.05)which was significantly greater than that of three monthes after treatment(p<0.05). The mean ADC values of survival group had no significant difference among one week before HIFU , one week and three monthes after HIFU(p>0.05).Conclusion: Dynamic contrast-enhanced MRI can sensitively reflect tumor necrosis and enhancement features after HIFU, providing residual and recurrence informations of PHC. But the identification for the remnant tumor cells within lesions or the tumor capsule was difficult using DCE-MRI, we must rely on regular follow-up MRI to judge. DWI can be sensitive to distinguish among tumor necrosis, remnant tumor tissue and recurrence and ADC value can quantitatively analyze tumor necrosis of primary hepatic carcinoma treated by HIFU. But DWI has lower-resolution images and is easy to create all kinds of artifacts. DWI and DCE-MRI combined to make up their own deficiencies and provide more information to guide clinical treatment. So DWI combined with DCE-MRI can have an important value in Evaluating the HIFU efficacy of primary hepatic carcinoma...