Dynamic Contrast-Enhanced and Intravoxel Incoherent Motion MRI Biomarkers Are Correlated to Survival Outcome in Advanced Hepatocellular Carcinoma

Perfusion MR Imaging of Liver: Principles and Clinical Applications

Perfusion imaging techniques provide quantitative characterization of tissue microvasculature. Perfusion MR of liver is particularly challenging because of dual afferent flow, need for large organ high-resolution coverage, and significant movement with respiration. The most common MR technique used for quantifying liver perfusion is dynamic contrast-enhanced MR imaging. Here, the authors describe the various perfusion MR models of the liver, the basic concepts behind implementing a perfusion acquisition, and clinical results that have been obtained using these models.

Molecular and functional imaging in cancer-targeted therapy: current applications and future directions

Targeted anticancer drugs block cancer cell growth by interfering with specific signaling pathways vital to carcinogenesis and tumor growth rather than harming all rapidly dividing cells as in cytotoxic chemotherapy. The Response Evaluation Criteria in Solid Tumor (RECIST) system has been used to assess tumor response to therapy via changes in the size of target lesions as measured by calipers, conventional anatomically based imaging modalities such as computed tomography (CT), and magnetic resonance imaging (MRI), and other imaging methods. However, RECIST is sometimes inaccurate in assessing the efficacy of targeted therapy drugs because of the poor correlation between tumor size and treatment-induced tumor necrosis or shrinkage. This approach might also result in delayed identification of response when the therapy does confer a reduction in tumor size. Innovative molecular imaging techniques have rapidly gained importance in the dawning era of targeted therapy as they can visualize, characterize, and quantify biological processes at the cellular, subcellular, or even molecular level rather than at the anatomical level. This review summarizes different targeted cell signaling pathways, various molecular imaging techniques, and developed probes. Moreover, the application of molecular imaging for evaluating treatment response and related clinical outcome is also systematically outlined. In the future, more attention should be paid to promoting the clinical translation of molecular imaging in evaluating the sensitivity to targeted therapy with biocompatible probes. In particular, multimodal imaging technologies incorporating advanced artificial intelligence should be developed to comprehensively and accurately assess cancer-targeted therapy, in addition to RECIST-based methods.

Application of intravoxel incoherent motion diffusion-weighted imaging in hepatocellular carcinoma

The morbidity and mortality of hepatocellular carcinoma (HCC) rank 6^th and 4^th, respectively, among malignant tumors worldwide. Traditional diffusion-weighted imaging (DWI) uses the apparent diffusion coefficient (ADC) obtained by applying the monoexponential model to reflect water molecule diffusion in active tissue; however, the value of ADC is affected by microcirculation perfusion. Using a biexponential model, intravoxel incoherent motion (IVIM)-DWI quantitatively measures information related to pure water molecule diffusion and microcirculation perfusion, thus compensating for the shortcomings of DWI. The number of studies examining the application of IVIM-DWI in patients with HCC has gradually increased over the last few years, and many results show that IVIM-DWI has vital value for HCC differentiation, pathological grading, and predicting and evaluating the treatment response. The present study principally reviews the principle of IVIM-DWI and its research progress in HCC differentiation, pathological grading, predicting and evaluating the treatment response, predicting postoperative recurrence and predicting gene expression prediction.

Early Diagnosis Value of DCE-MRI Hemodynamic Parameters in Hepatocellular Carcinoma

Objective

To probe into the early diagnosis value of transfer coefficient (K^trans) and rate constant (K_ep) of the dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) hemodynamic parameters in patients with hepatocellular carcinoma (HCC).

Methods

Fifty patients with HCC diagnosed in our hospital from May 2017 to May 2020 were studied retrospectively as the patient group (PG), and 45 cases with benign liver nodules diagnosed in our hospital during the same period were collected as the control group (CG). K^trans, K_ep, and AFP levels were compared between PG and CG. The diagnostic value of K^trans and K_ep in HCC were observed, and their correlations with patient clinical data were analyzed. The diagnostic value of K^trans and K_ep combined with AFP in clinical staging, differentiation degree, and distant metastasis was compared.

Results

K^trans, K_ep, and AFP were notably higher in cases than in controls (P < 0.05), indicating their high diagnostic value in HCC. K^trans and K_ep present elevated expression in HCC patients with clinical stage III-IV, low differentiation, and distant metastasis (P < 0.05). Furthermore, it is found that the combined detection with either K^trans or K_ep can improve the clinical diagnostic value of AFP in the clinical stage and differentiation of HCC. However, the combined diagnosis showed little effect in raising the sensitivity of AFP in distant metastasis.

Conclusion

DCE-MRI hemodynamic parameters K^trans and K_ep have high clinical value in early diagnosis and differentiation of HCC patients.