Dephasing and diffusion on the alveolar surface.

We propose a surface model of spin dephasing in lung tissue that includes both susceptibility and diffusion effects to provide a closed-form solution of the Bloch-Torrey equation on the alveolar surface. The nonlocal susceptibility effects of the model are validated against numerical simulations of spin dephasing in a realistic lung tissue geometry acquired from synchotron-based µCT data sets of mouse lung tissue, and against simulations in the well-known Wigner-Seitz model geometry. The free induction decay is obtained in dependence on microscopic tissue parameters and agrees very well with in vivo lung measurements at 1.5 Tesla to allow a quantification of the local mean alveolar radius. Our results are therefore potentially relevant for the clinical diagnosis and therapy of pulmonary diseases.

A Review of Scientific Topics and Literature in Abdominal Radiology in Germany - Part 1: Gastrointestinal Tract.

UNLABELLED: The working group for abdominal and gastrointestinal diagnosis is a group of the German Radiological Society (DRG) focusing clinically and scientifically on the diagnosis and treatment of the gastrointestinal tract with all parenchymatous abdominal organs. In addition to the clinical and scientific further development of abdominal radiology, the education of radiologists within this core discipline of radiology is one of the major aims. In this article we give an up-to-date literature review of scientific radiological topics especially covered by German radiologists. This manuscript focuses on the most recent literature on the diagnosis of the stomach, small bowel, colon and rectum. The review with a focus on the most recent studies published by German radiologists concludes with a synopsis of mesenterial bleeding and ischemia followed by a critical appraisal of the current literature on conventional abdominal radiography. KEY POINTS: Based on recent literature and guidelines there is a change of paradigms regarding the diagnosis of esophagus and gastric cancer towards CT, which is considered equally to endosonography. For small bowel imaging in Crohn's disease ultrasound as well as MRI with a new focus on DWI are the most important imaging modalities scientifically. For colonic diagnosis virtual colonoscopy has replaced the conventional radiological methods. For staging of rectal carcinoma as well as for therapeutic stratification a high resolution MRI of the pelvis is of paramount interest. Multislice CT is considered the most important modality to assess mesenteric ischemia or bleeding.