Separation of diffusion and perfusion in intravoxel incoherent motion MR imaging

Intravoxel incoherent motion (IVIM) imaging is a method the authors developed to visualize microscopic motions of water. In biologic tissues, these motions include molecular diffusion and microcirculation of blood in the capillary network. IVIM images are quantified by an apparent diffusion coefficient (ADC), which integrates the effects of both diffusion and perfusion. The aim of this work was to demonstrate how much perfusion contributes to the ADC and to present a method for obtaining separate images of diffusion and perfusion. Images were obtained at 0.5 T with high-resolution multisection sequences and without the use of contrast material. Results in a phantom made of resin microspheres demonstrated the ability of the method to separately evaluate diffusion and perfusion. The method was then applied in patients with brain and bone tumors and brain ischemia. Clinical results showed significant promise of the method for tissue characterization by perfusion patterns and for functional studies in the evaluation of the microcirculation in physiologic and pathologic conditions, as, for instance, in brain ischemia.     

Osteoinductivity assay of the variability of repeated extractions of bone morphogenetic proteins from bovine bone at different times

BOrthobiologicsLaboratory ,DepartmentofOralMaxillofacialSurgery,FacultyofDentistry ,UniversityofToronto ,Canada (HuZH ,SeanA .F .PeelandCameronM .L .Clokie)DepartmentofOrthopaedicSurgery,TheAffiliatedSecondHospital,KunmingMedicalCollege ,1Mayuan ,Kunming ,Yunnan6 5 0 10 1,China (HuZH) Correspondingauthor:Tel:86 871 5 35 12 81 2 5 95 ,E mail:zminghu @hotmail.comonemorphogeneticproteins (BMPs)aremembersoftransforminggrowthfactor (TGF )superfamilyencodingpolypeptidesthatshareco…     

Illusory consolidation of the left lower lobe: a pitfall of portable radiography

The definition of the left hemidiaphragm is frequently lost when patients are evaluated with portable radiographic equipment. Experimental evidence, based on results of radiography and subsequent sagittal sectioning of a frozen, unembalmed human thorax, corroborated the authors' hypothesis that this finding is related to loss of tangential imaging of the apex of the hemidiaphragm due to cephalic angulation of the central beam accompanied by projection of extrapleural fat onto the base of the left lung. In eight of ten patients in whom portable radiography was performed in 10 degrees-15 degrees of lordosis, varying degrees of loss of definition of the left hemidiaphragm were seen, in the absence of disease. This potential pitfall can be avoided by ensuring that the central beam is tangent to the hemidiaphragm. To do otherwise can create the false impression of disease in the left lower lobe, pleural space, or both.