Background: Multiple sclerosis (MS) is a chronic disease that begins most commonly in young adults and is characterized pathologically by multiple areas of central nervous system (CNS) white matter inflammation, demyelination, and glial scarring. The most valuable aid for diagnosis is magnetic resonance imaging (MRI). New type of MRI has been developed on the basis of molecular diffusion which capable of detecting acute and active lesions. Early diagnosis and treatment is possible to stop or slowdown progression of disease. The aim of this study is to compare the findings of conventional and diffusion- weighted (DW) MRI in detection cerebral lesions of MS.Methods: Thirty patients with clinically definite MS and 30 healthy volunteers were studied in a descriptive-prospective survey over a twelve-month period of time.Conventional and DW MRI were used in both groups. Total number, morphology, location and the mean size of the intra-cerebral plaques of MS were compared between group. The sensitivity and the specificity of both imaging methods in detecting these plaques were determined.Results: Thirty patients with MS with the mean age of 32.76±8.79 years and 30 healthy individuals with the mean age of 32.75±9.23 years were enrolled. Plaque within the brain was significantly higher by the conventional method (P<0.05). Ovoid lesions were greater in number in the conventional method group. More lesions were detected by the conventional method in the areas of periventricle, centrum semiovale and corpus callosum. Regarding the size of plaque, the minimum measurement was significantly lower in the conventional method group. The sensitivity of both methods was 100%. The specificity of conventional and DW MRI was 86.6% and 96.6%, respectively.Conclusion: In our study the sensitivity of both methods was the same but the specificity of DW MRI was higher. DW MRI may detect lesions which are not detectable by the routine methods.

Accurate knowledge of the basic principle of imaging physics helps better understanding of normal anatomy and pathological imaging findings of the diseases.This is more necessary in advanced imaging techniques like MRI because of the complexity of the basic physics of the technique. In basic MRI physics workshop, we discuss about this technique from the primary concepts. The content is very simplified and is showed by slides, animation and easy pictures for better understanding. In the beginning of the lecture, the structure of atoms and their magnetic characteristics are explained and then step by step, we learn how to use this character to produce signal and usages of it to make an image. Also basic pulse sequence will be explained subsequently. This workshop is recommended for all radiologists, residents of radiology, technologists and anyone who wants to know more about MRI.

MRI is a useful supplement to ultrasonography for the assessment of fetal brain malformations. Superior soft tissue contrast and the ability to depict sulcation and myelination are the strengths of MRI. Subtle or inconclusive ultrasonography abnormalities can be confirmed or ruled out by MRI. In some cases, additional findings detected with MRI often help in arriving at a definitive diagnosis, which is necessary for parental counseling and for guiding management. Fast T2W sequences form the basis of fetal MRI. There have been no reports of deleterious effects of MRI on the fetus. A few case examples are presented to illustrate the advantages of MRI. The database comprises MR images of a total of 26 fetuses (gestational age 22-23 weeks) reformed be-cause of suspected abnormalities due to ultrasonic findings, family history or maternal illness and scanned on a 1.5T MR system using single-shot fast spin echo "SSFSE, HASTE" T2 sequence, slice thick-ness 3mm, no gap. "HASTE=fourier acquisition single shotturbospinecho". In the normal fetus the ventricular size or volume did not vary with the gestational age but cerebral and cerebellar volumes increase during the same period "Grossman et al." Diagnostic accuracy is about 48%. "OB/GYN news, Chicago". Today it is not necessary to use sedatives or muscle relaxants to control fetal movement "ultra-fast MRI techniques". Modified technique for 50% reduction in the time necessary to take MRI images of the fetal brain is dedicated by Kianosh Hosseinzadeh, by using a line of reference through the eyes "AJR 2005".Our fetuses are 22-23 weeks in gestational age, 26 in number and we found agenesis of corpus callosum, hydrocephaly, holoprosencephaly, mega-cisterna magna, occipital meningocele, Arnold Chiari malformation type 1, Dandy Walker syndrome and lissencephaly.

Time-resolved MR angiography techniques have re-salted in the clinical feasibility of high spatial and temporal resolution of dynamic contrast-enhanced MRA, enabling imaging the passage of contrast through the vasculature, and temporal separation of arterial and venous flow. Ability to use continuously moving MR tables has led to more efficient MRA run-off studies and made multisequence whole body MRI studies a clinical reality. Advances in variable flip-angle MRI methods have opened new horizons in both gradient echo and FSE imaging. Using these techniques, now high-resolution isotropic 3D FSE imaging has become possible in a reasonable clinical timeframe and without exceeding SAR limits. Acquisition of sub-mm isotropic vowels has opened up the possibility of routine multilane reformatting of MRI images just like multidetector CT images, which may obviate the need for MR data acquisition in multiple planes. Use of iterative decomposition, SPAIR, and Dixon methods of fat suppression has lead to vastly improved and homogenous images of selective fat or water suppression with decreased arty-facts. Whole-body diffusion-weighted imaging with or without background signal suppression is a new method for evaluation of cancer metastases and ma-lignin lymphadenopathy. It is currently being investigated as a potential alternative to PET scanning in diagnosis and follow-up of cancer patients. Susceptibility-weighted imaging makes use of the ad-additional information provided by phase maps, which are usually discarded in routine MRI, to better de-lineate flow in venues and greatly enhances the de-section of micro hemorrhages and other sources of susceptibility.

Introduction: Diastematomyelia is one of the uncomon and occult spinal dysraphisms.The term is derived from two latin word: diastemato means split and myelous means cord. The pathological characteristics consist of longitudinal cleft in the spinal cord of the lower thoracic and upper lumbar spinal colummn in children and rarely in adults.This report has encountered with 4 cases during one year (2003-2004) in M.R.I. centers of university and private clinic that MRI showing a midline dimple shape and hemicord appearance.This study and article found that patient diagnosis with MRI is more reliable and more accurate than other radiological techniques specially CT scanning, because of multisectional and multiplanners for a better view of the lesion.In this study most of patients are a female infant with a majority of clinical neurologic findings including motor and sensory loss in the lower extremities and bladder dysfunction.

The purpose of this study was to investigate magnetic resonance imaging (MRI) of the normal feline eye and optic nerves using T1-weighted and T2-weighted images. A total of 6 healthy female domestic short hair cats age 2-2.5 years and weighing 3.2±0.4 kg were selected. Magnetic resonance imaging data were collected using GEMSOW (Philips) at a magnetic field strength of 1.5 T. Dorsal, sagittal, and transverse plane images were obtained from left and right eyes. Intraocular structures of the cats visible on T1-weighted and T2-weighted images include cornea, anterior chamber, posterior chamber, lens, iris, sclera, and chiasma.Cornea was well detected in T1-weighted, the iris in T2-weighted and chiasma was well detected in T2- weighted in dorsal plane. Measurements of the visible structures on T1-weighted and T2-weighted images did not show any significant difference between the left and right eyes (P>0.05). MRI provides excellent anatomical detail of the feline eye and optic nerve due to its superior soft tissue contrast and its multiplanar and multislice imaging capability.