Editorial

This issue again presents advanced MR imaging techniques to study of somatosensory-motor processing and multiple sclerosis, MR cisternography and myelography, quantitative ultrasound for fetal growth and skeletal status, and various techniques to visualize DNA repair proteins. Magnetic encephalography (MEG) has been used to measure the magnetic field produced by electrical activity in the brain via extremely sensitive devices such as superconducting quantum interference devices. This assists a localization of pathologic lesions and determination of functional parts of the brain. Drs. Kida and Kakigi review basic concepts of MEG in comparison with EEG and clinical studies of attention and somatosensory-motor interaction as well as movement disorders. Multiple sclerosis (MS) is characterized by inflammation and scarring of the CNS, and MS plaques are often hypointense to white matter on precontrast T-1-weighted images. However, this finding lacks a specificity since many other diseases can produce white matter lesions with similar appearance. There is a poor association between clinical and radiological findings. Hypointense spinal cord lesions on T1-weighted images correlate better with functional disability than brain lesions, possibly because cord lesions are more likely to involve motor tracts. Dr. Lenzi et al. discuss functional MRI studies to demonstrate a brain reorganization or adaptive mechanism in patients with MS. Cisternography using intrathecal contrast agent has been used for many years in the diagnostic evaluation of disease processes involving the basilar cisterns and skull base, and myelography has also been an important diagnostic modality for a wide range of spinal diseases. Injection of Gd-DTPA into the subarachnoid space can enhance the contrast between CSF, brain, spinal cord and surrounding meninges and bones. This is very helpful to evaluate tumors adjacent to the CSF spaces, abnormal CSF collections, CSF rhinorrhea and otorrehea, syringohydromyelia, and studies of hydrocephalus as well as CSF flow dynamics. Drs. Sprague and Berkman report a case of compression fracture secondary to cement leakage into the disc space during the vertebroplasty procedure. Ultrasound (US) is an inexpensive and widely used imaging modality for the diagnosis and evaluation of a number of diseases. In the last decade, investigators and commercial companies have advanced US imaging with the development of 3D technique. This new imaging approach is rapidly achieving widespread use with numerous applications. Drs. Hata and Dai review quantitative 3D power Doppler in the assessment of the vascularization and blood flow of the fetal organs and placenta for the evaluation of fetal growth and development. Quantitative US (QUS) measures the US beam changes when it passes through the bone, called as broad band ultrasonic attenuation, and also measures the speed at which the beam passes. It has proven its utility in the detection of skeletal changes in various disorders. There is also an increasing interest for the screening of osteoporosis since it predicts fracture risk. Dr. Halaba discusses the usefulness of phalageal QUS in the assessment of skeletal status in children and adolescents. Cells continuously suffer from DNA damage and all cells must quickly mend any breaks that occur in their DNA strands. The double strand break (DSB) is most dangerous one due to the potential development of cancer. Cancer cells are dependent on a process called homologous recombination to repair DNA and stay alive. That is what makes them resistant to drug or radiation therapy. Dr. Krawczyk et al. summarizes different techniques that can be used to visualize proteins involved in DSB repair process. They are X-ray crystallography, confocal, electron, fluorescence or scanning force microscopy, immunocytochemistry, fluorescence resonance energy transfer, and fluorescence recovery after photobleaching.