State-of-the-art MR imaging in the work-up of primary hepatocellular tumors

Magnetic resonance (MR) imaging is an imaging modality that has evolved rapidly in the past two decades. The development of advanced hardware and new sophisticated pulse sequences have allowed faster imaging, with increased temporal and spatial resolution. This has resulted in the development and implementation of new acquisition techniques that facilitate improved visualisation of neoplastic processes. In addition, faster sequences enable multiphasic dynamic imaging after intravenous administration of contrast material, which results in better tumor characterisation and improved diagnostic confidence by the reading radiologist. The radiologic imaging work-up of primary hepatic tumors has improved considerably as a result of these developments. MR imaging is an imaging modality that is highly valuable for the diagnostic strategy for these tumors, since the combination of several T1- and T2-weighted sequences before and after administration of a gadolinium-chelates allows determination of intrinsic tissue charactistics of the lesion, with possibility to detect neovasculaturity in an early stage. These characteristics make MR imaging an ideal imaging modality for detection and differentiation of focal liver lesions. Primary liver nodules are categorized according to the regenerative or dysplastic nature of the lesion, in combination with the anatomic characteristics of adjacent hepatic stroma. Most common lesions are focal nodular hyperplasia (FNH), hepatocellular adenoma (HCA) and hepatocellular carcinoma (HCC). The clinical and surgical management of these entities differs, therefore accurate differentiation based on state-of-the-art MR imaging plays an essential role in the diagnostic work-up of these patients. This thesis describes various new insights in the MR imaging findings of primary hepatocellular tumors, with emphasis on non-invasive diagnostic possibilities in young women with FNH or HCA and improved early diagnosis of developing HCC in cirrhosis. In addition, because of the importance of higher field MR imaging systems for the work-up of primary liver lesions, this thesis also includes a section on the technical developments in high field MR imaging and post-processing strategies for improved semi-automated diagnosis in the future.

• View at Worldcat

Free Full Text ( Final Version , 4mb )