Tumor hemodynamics of carcinogenic hepatocytes nodules, that is, low grade dysplastic nodules, high grade dysplastic nodules, early hepatocellular carcinomas (HCCs), and progressed HCCs, change during multistep dedifferentiation of the nodules. Morphometric analyses of inflow vessels of these nodules indicate that the portal veins of carcinogenic hepatocyte nodules monotonically decrease wherea...

Electronic portal imaging devices (EPIDs) are potentially valuable tools for linear accelerator quality assurance and for measuring and analyzing geometric variations in radiation treatment delivery. Geometric analysis is more robust if referenced against an absolute position such as the isocenter (collimator axis of rotation), allowing the observer to discriminate between various setup errors ...

PURPOSE In this paper, the effect on image quality of significantly reducing the primary electron energy of a radiotherapy accelerator is investigated using a novel waveguide test piece. The waveguide contains a novel variable coupling device (rotovane), allowing for a wide continuously variable energy range of between 1.4 and 9 MeV suitable for both imaging and therapy. METHOD Imaging at lin...

Improvements in imaging technology are impacting on every stage of the radiotherapy treatment process. Fundamental to this is the move towards computed tomography (CT) simulation as the basis of all radiotherapy planning. Whilst for many treatments, the definition of three-dimensional (3D) tumour volumes is necessary, for geometrically simple treatments virtual simulation may be more speedily p...

Introduction: Electronic portal imaging devices (EPIDs) are fundamentally used for instantaneous verification of the patient set‐up, block shape, and leaf positions during radiation therapy. In radiotherapy, situations arise in which an inclined PTV must be treated mutually with adjacent nodal regions. This methodology is most widely used for matching tangential/lateral breas...

Introduction: Electronic Portal Imaging Device (EPID) and Cone Beam Computed Tomography (CBCT) are the preferred tools of Image Guided Radiotherapy (IGRT) and Dose Guided Radiotherapy (DGRT) which have been used for Radiotherapy treatment verifications. As a result, the number of publications dealing with these two tools for radiation treatment verification has increased consi...

Introduction: Portal hypertension (PHTN) is a complication of cirrhosis associated with significant morbidity, including varices, variceal rupture, ascites, portal venous thrombosis, and encephalopathy. Current non-invasive evaluation of PHTN is confined to angiographic assessments with MRA and CTA and limited hemodynamic assessment with ultrasound. Recent work has described the ease of demonst...

case presentation we report a case of idiopathic colonic varices, diagnosed at a routine colonoscopy performed for nespecific abdominal disturbances in a female patient without liver disease or pancreatic conditions responsible for portal hypertension development. conclusions the development of colonic varices in the absence of a certain trigger represents a major issue for practitioners due to...