Published online Jun 14, 2015. doi: 10.3748/wjg.v21.i22.6794
Peer-review started: January 28, 2015
First decision: March 10, 2015
Revised: March 25, 2015
Accepted: May 2, 2015
Article in press: May 4, 2015
Published online: June 14, 2015
Processing time: 141 Days and 14.5 Hours
Diffusion-weighted imaging (DWI), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and perfusion computed tomography (CT) are technical improvements of morphologic imaging that can evaluate functional properties of hepato-bilio-pancreatic tumors during conventional MRI or CT examinations. Nevertheless, the term “functional imaging” is commonly used to describe molecular imaging techniques, as positron emission tomography (PET) CT/MRI, which still represent the most widely used methods for the evaluation of functional properties of solid neoplasms; unlike PET or single photon emission computed tomography, functional imaging techniques applied to conventional MRI/CT examinations do not require the administration of radiolabeled drugs or specific equipments. Moreover, DWI and DCE-MRI can be performed during the same session, thus providing a comprehensive “one-step” morphological and functional evaluation of hepato-bilio-pancreatic tumors. Literature data reveal that functional imaging techniques could be proposed for the evaluation of these tumors before treatment, given that they may improve staging and predict prognosis or clinical outcome. Microscopic changes within neoplastic tissues induced by treatments can be detected and quantified with functional imaging, therefore these techniques could be used also for post-treatment assessment, even at an early stage. The aim of this editorial is to describe possible applications of new functional imaging techniques apart from molecular imaging to hepatic and pancreatic tumors through a review of up-to-date literature data, with a particular emphasis on pathological correlations, prognostic stratification and post-treatment monitoring.
Core tip: Diffusion-weighted imaging and perfusion imaging could add functional information to the morphological evaluation of hepatic and pancreatic tumors. Diffusion-weighted imaging findings seem to be correlated with pathological features and could predict the clinical outcome of hepatocellular carcinomas and pancreatic tumors, especially neuroendocrine neoplasms. Apparent diffusion coefficient quantification and perfusion techniques can be of value for the evaluation of response to ablative treatments, loco-regional therapies and anti-angiogenic therapies, even at an early stage.