Diffusion weighted MRI in evaluation of solid focal hepatic lesions

ABSTRACTBackground: The liver is an organ in which various benign or malignant primary or secondary masses can be detected. Accurate detection and characterization of focal liver lesions (FLLs) are important for treatment planning for patients with liver neoplasms such as hepatocellular carcinoma (HCC) and metastases. Size and number of lesions can affect therapy. For example, patients may benefit from curative resection and patients with fewer than three small HCCs are candidates for liver transplantation. Patients with more extensive disease should instead undergo transarterial chemoembolization, radiofrequency ablation, or systemic chemotherapy.Objective: To role out diagnostic efficiency of diffusion weighted MRI in solid focal hepatic lesions.Patients: This study included (30) patients with solid focal hepatic lesions (on the basis of ultrasonographic examination) they were referred from General Medicine, Oncology and Tropical Departments of Zagazig University Hospitals .They were (16) males and (14) females, their ages ranged from 28 to 70 years .They were referred to Radiodiagnosis Department of Zagazig University during period from September 2009 to August 2010.Results: At the end of this study we suggested an algorithm for the diagnosis of solid focal hepatic lesions: Patient screening at first by US examination to road map site, size and number of the focal lesions as well as suggest a radiological diagnosis. Conventional MRI study supplemented by diffusion weighted scan is better to be performed as the next step. If the suggested diagnosis by diffusion study matches with that of conventional sequences we believe that no need for further assessment by post contrast study or enhanced CT scan.Conclusion: Diffusion weighted (DW) MRI is a useful non invasive technique in characterizing focal liver lesions. Echo planar imaging sequences with variable motion probing gradients (MPGs) revealed that benign lesions have large apparent diffusion coefficient compared to malignant lesions and thus helping in differentiating between benign and malignant lesions, except some overlap between some metastatic lesions and hemangiomas and between lipoma and malignant lesions. Finally a combined use of diffusion weighted MR imaging and conventional MR imaging may further improve the differentiation between benign and malignant focal lesions and may result in financial savings by reducing the necessity for gadolinium enhanced MR imaging.