Role of Dynamic Contrast Enhanced MRI and Diffusion Weighted Imaging in Evaluation of H.C.C after Chemo-Embolization

Abstract
Background: Hepatocellular Carcinoma (HCC) is the most common primary malignant disease of the liver and is the third leading cause of death from cancer worldwide. Dynamic Contrast-Enhanced MRI (DCE MRI) can play a significant role as an imaging of H.C.C, especially in the detection of viable tumor foci, the differentiation between necrosis and viable tumor after TACE and early prediction of response. Diffusion-weighted MRI shall be more frequently used for tumor response evaluation to TACE because they provide detailed anatomic and functional or metabolic change information during tumor treatment, particularly during tar-geted chemotherapy.
Aim of Study: Detection of the value of DCE (Dynamic contrast enhanced) MRI and DWI (Diffusion Weighted Imag-ing) in evaluation of HCC (Hepatocellular Carcinoma) necrosis after TACE (Trans-Arterial Chemo-Embolization).
Material and Methods: Pre-contrast T1 and T2 WIs fol-lowed by diffusion weighted MR images (several b factors 20, 500, 800s/mm2) then DCE MRI study using a 3 Telsa scanner followed by measuring different ADC values obtained in 30 patients underwent TACE for treatment of 40 HCC lesions for assessment of tumoral necrosis. ADC cut-off number was estimated using the ROC curve after measuring ADC values for all cases.
Results: Statistical analysis demonstrated that Dynamic MRI had sensitivity of about 100% and 95.24% for specificity, While DWI has level of sensitivity of about 52.63% and 90.5% as a degree of specificity.
The difference between well-ablated and residual/newly developed groups'.
ADC values was found to be significant statistically (p-value <0.001) and best cut-off variable that maximize specif-icity and sensitivity is 1.35, where sensitivity level reaches about 78.9% and specificity level reaches about 85.7%.
Conclusions: Depending on our study, dynamic MRI showed very high sensitivity while DWI with ADC mapping series alone have low level of sensitivity so it promotes reader confidence and might be used in case of gadolinium contra-indications or in case of incapability of breath holding ade-quately.