Editorial

Diffusion-weighted imaging (DWI) shows the changes in signal intensity resulting from the motion of water molecules by diffusion. The signal loss produced by the translational molecular movement in an MR image increases with the speed at which the molecules move through a magnetic gradient field. DWI is an area of intense research because it provides unique information that can not be obtained with other methods or only to a very limited extent. Diffusion tensor imaging (DTI) is mainly used for so-called fiber tracking (tractography) in cerebral white matter. Dr. Anneriet Heemskerk et al. presents a paper to provide insight into the relationship between structure and function in skeletal muscle by DTI-based longitudinal studies on the principle that waterdifuses more readily along the long axis of muscle fibers than along the transverse axis. Simultaneous EEG and electromyograpgy during functional MRI is very useful in the evaluation of epilepsy and movement disorders. Dr. Pasquale Paolantonio et al. addresses a detailed morphological information about the small bowel by using advanced MRI with high magnetic field, phased array coil and fast imaging sequences as well as oral contrast agent or nasojejuneal catheter. MRI of small bowel is useful in the evaluation of inflammatory bowel disease by demonstrating bowel wall thickness and contrast enhancement. Some patients demonstrate blunted hemodynamic response (BHR) during the stressed myocardial perfusion imaging with adenosine infusion. Dr. Isis Gayed et al. report no significant difference in the frequency of abnormal myocardial perfusion in patients with BHR compared with normal hemodynamic response. However, patients with BHR more frequently larger myocardial scars than those with normal response. Despite its proven clinical utilities, FDG PET has well known limitations in evaluation cancer patients with false positive and negative findings. Several other agents have been developed for PET to provide new information on the biologic, metabolic and molecular characteristics of malignant tumors. Dr. Asit Paul et al. review choline, acetate. methionine, thymidine and misonidazole as well as their clinical applications. Metabotropic glutamate receptors (mGluRs) belong to a superfamily of G protein coupled receptors and are considered to affect on dopaminergic and adrenergic neurotransmission. Receptor ligands binging to mGluRs are also considered as potential therapeutic agents. Dr. Ji-Quan Wang et al. discuss a number of radiotracers useful for imaging specific mGluRs and their biological properties with the emphasis on highly potent and selective allosteric modulators for radiolabeling with F-18 and C- 11 for PET. There is a need for new approaches to diagnose and treat infectious disease due to increasing problems caused by highly resistant microorganisms and also no available therapy for new microbes. Radioimmunotherapy using microbe-specific antibodies and suitable radionuclides has been recently suggested as a novel treatment and holds enormous potential. Dr. Ekaterina Dadachova reviews a monoclonal antibody against cryptococcus labeled with bismuth-213 or rhenium-188. The use of bone seeking radiopharmaceutical for the treatment of metastatic bone pain has increased in popularity over the past decade and thus opened new possibilities for other applications of this agent as a component of multi-modality treatment regimen for primary and metastatic bone tumors. Dr. Stephanie Essman discusses a targeted radiotherapy using Sm-153 EDTMP for the treatment of osteosarcoma and also effect on the skeletal growth in a rabbit model.