R N Sener

..To evaluate metabolic and toxic brain disorders that manifest with restricted, elevated, or both restricted and elevated diffusion patterns on diffusion magnetic resonance imaging (MRI)...

..42+/-0.17 x 10(-3)mm(2)/s) patterns. Diffusion imaging appears to be a promising sequence to evaluate the changes in the brain tissue in Wilson's disease at least by revealing two different patterns...

..Two different diffusion patterns were evident: a restricted diffusion pattern in the globi pallidi and an increased diffusion pattern in the white matter...

..A reverse pattern was evident in the cerebellar cortex with high ADC values. This was likely a reflection of dysmyelination or lack of myelination...

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..On the apparent diffusion coefficient (ADC) map of an echo-planar diffusion imaging sequence, their ADC value ranged between 1.98 and 2.27x10(-3) mm(2)/s, a value higher than that of normal cerebral parenchyma, less than that of CSF...

..Low signal on ADC maps and low ADC values are evident. These represent characteristic diffusion MRI features of normal iron deposition in the brain, reflecting susceptibility effects...

..63 to 0.97 x 10(-3) mm2/s. It is suggested that the areas of increased signal (and low ADC values) are the result of dysmyelination as a reflection of disorganized tissue integrity...

..96 and 0.97 x 10 x (-3) mm(2)/s, respectively, excluding cytotoxic edema. The changes were shown to be resolved on a 9-month follow-up MRI...

..30 to 2.20 x 10 x (-3)mm(2)/s (mean: 1.78+/-0.27 x 10 x (-3) mm(2)/s), compared to the normal ADC values of the splenium in controls: 0.78+/-0.12 x 10 x (-3) mm(2)/s...

..Further spectroscopic and clinical studies are required to evaluate this observation...

..Occurrence of cystic degeneration in the temporal tips distinguished the condition from other leukoencephalopathies. This leukoencephalopathy appears to be a new distinct entity...

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..Epidermoid tumors originating from the brainstem are extremely rare. The authors report a patient with an intraaxial epidermoid tumor of the pons. The tumor involved most of the pons and had a small exophytic component...

..The pathogenesis of intra-axial locations is still controversial, and this article proposes that in at least some cases intraparenchymal rupture of dermoids can cause intra-axial dermoids...

..On the other hand, the ADC values of the cortex were normal (0.79-0.95 X 10(- 3) mm(2)/s). These findings on spectroscopy and diffusion MRI likely represented deficient myelination in the disease...

..The PSIF sequence revealed pixel value differences between the two hemispheres. Proton MR spectroscopy revealed decreased N-acetyl aspartate peaks, compared with five control cases...

..56 x 10-3 mm2/s. On proton MR spectroscopy obtained in 1 of the patients, a prominent peak resonating at approximately 3.80 ppm was consistently present attributable to the peak rising from the alpha-proton of the phenylalanine molecule...

..Diffusion MR imaging findings likely reflected the histopathologic changes of the disease which consisted of spongiosis of the myelinated brain tissue due to myelin vacuolation...

..The ultimate clinical effect of this fatty tissue was urinary dysfunction, radicular pain and hypoesthesia in both legs and difficulty walking...

..Such an association likely represents a new anomaly of the hindbrain and spine...

..11 x 10(-3) mm2/s). High ADC values of solid vestibular schwannomas were in conformity with increased diffusion rates, indicating the presence of increased amounts of extracellular water (a relatively loose tissue) in the tumor matrix...

..In conclusion, diffusion MRI provided useful imaging data on different types of encephalitis, either on b= 1000 s/mm(2) images or on ADC maps, or on both...

..52 x 10(-3)mm(2)/s, consistent with acute ischemic infarction (cytotoxic edema). The ADC values of a relatively old lesion in the left occipital region ranged between 1.65 and 1.82 x 10(-3)mm(2)/s, consistent with chronic infarction...

..Very prominent peaks centered at 1-1.5ppm were noted in spectroscopic analysis, which probably corresponded to lipid/cholesterol peaks, correlating with the histological findings revealing high amounts of cholesterol in the cyst fluids...

..Further studies can provide addition of different lesions as well as refinements of these categories...

..It can be concluded that a mesenchymal disorder can be the primary cause for an open falcine sinus either in isolation or in association with variable changes in the straight sinus...

..Our findings suggested that the frequency of rhombencephalosynapsis appears to be higher than previously thought (approximately 0.13%), and it should not be misinterpreted as Chiari II malformation...

..The condition was named as aventriculi. In this paper, the second example of aventriculi is reported in a 1 month-old girl by MR imaging...

..TE = 40 ms). This study revealed apparently improved NAA/Cho (2.63), NAA/Cr (2.13) ratios in the hamartoma compared to the initial examination at three months of age, excluding the possibility of a neoplasm...

..Cranial MR imaging examination findings of a three and half year old boy with Waardenburg syndrome are described which consisted of bilateral congenital anophthalmia (secondary type), and a hypothalamic hamartoma...

..The anatomy of the choroid plexus and the fact that the frontal horns do not contain choroid plexuses are emphasized...

..A clinical follow-up 2 years later revealed normal findings...

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..85 x 10(-3)mm(2)/s). In FLAIR images, obtained after administration of intravenous contrast medium, an intense, diffuse enhancement pattern was seen involving the viable tumor portions as well as the intratumoral fluid...

..12 x 10(-3)mm(2)/s less than that of CSF. The matrix of the tumor had lower ADC values ranging from 1.19 to 1.25 x 10(-3)mm(2)/s, higher than that of normal cerebral parenchyma...

..Further studies on tuberous sclerosis, and on various brain lesions, would provide increasing data on this relatively new MRI sequence...

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..Diffusion MRI findings suggested that tectal tumors had a relatively high nuclear to cytoplasmic ratio (high-signal on b=1000 s/mm(2) images) in association with a relatively loose intercellular matrix (high ADC values)...

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..In addition, a distinct and prominent glycine peak was observed at 3.50 ppm, reflecting excitotoxic brain damage...

..0001). This difference suggested that in the postmortem brain the conditions in the white matter leading to restriction of movement of water molecules are more severe than that in the cortex...

..There was no clinical correspondence for these. The condition was attributed to an artefact created by a relatively deep interpedincular cistern leading to a volume-averaging effect...

..A patient with ectodermal dysplasia, Joubert's syndrome, and cerebral cysts is reported. The combination of these findings suggested a disorder of the embryonic ectoderm, manifesting as a neurocutaneous syndrome...

..37 to 1.63 x 10(-3 )mm2/s. It is likely that these values reflected presence of two different histopathological changes in phenylketonuria or reflected different stages of the same disease...

..Also, ADC values of perilesional vasogenic edema (1.74 x 10(-3) mm(2)/sec), and that of transependymal resorption of CSF (1.56 x 10(-3) mm(2)/sec) were noted at the initial stage...

..Globus pallidus lesions likely represented neuropathologic changes such as astocytosis, delayed myelination, and status spongiosus (myelin splitting and vacuolation)...

..The differentiation of encephalitis and gliomas based on MR findings could reliably made with short time follow up MR examinations where gliomas tend to grow in contrast to encephalitis which showed regression...

..These observations consisting of a restricted diffusion pattern on diffusion MR imaging, and decreased choline peaks on proton spectroscopy, likely represented dysmyelination in metachromatic leukodystrophy...

..ADC maps, however, revealed high ADC values (1.76, and 1.66 x 10(-3) mm2/s), compared to the normal brain parenchyma (0.81 x 10(-3) mm2/s). These diffusion MR imaging findings likely represented gliosis...

..This suggests that the peak at 3.50 ppm in patients with van der Knaap syndrome may belong to glycine, as a slight shift in peak resonances is possible as a result of spatial electron interactions...

..37 to 1.63x10(-3) mm2/s. It is likely that these values reflected presence of two different histopathological changes in phenylketonuria or reflected different stages of the same disease...

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..Application of the CISS sequence is recommended in the diagnosis of sacral meningeal cysts...

..This was likely a reflection of benignity of these slowly growing tumors...

..54 x 10(-3) mm2/s. Those of the spared tegmentum and longitudinal bundles were normal, ranging between 0.89 x 10(-3) to 1.04 x 10(-3) mm2/s, compared with the values from the normal-appearing regions of the cerebellar parenchyma...

..It is likely that this reflected necrosis, spongiform degeneration, and demyelination, which are among the known histopathologic changes associated with Wilson disease...

..CT examination of the father revealed prominent muscular atrophy, and widespread fatty degeneration of the psoas, paraspinal, gluteal and femoral muscles...

..On the other hand, ADC values of the lissencephalic cortex were normal, ranging from 0.95 to 0.97 x 10(-3)mm2/s. In addition, ADC values from the hypoplastic cerebellar hemispheres, and from the hypoplastic pons were normal...

..These diffusion MR imaging features of the colloid cyst are consistent with an elevated diffusion pattern in contrast to epidermoids...

..Dystrophic axons likely account the restricted diffusion, whereas spheroid formation (swelling) and abnormal myelination result in elevated diffusion...

..08-1.12 x 10(-3) mm(2)/s), compared with the apparent diffusion coefficient values from the normal white matter regions. Apparent diffusion coefficient values in the globus pallidi were lower than those in the unaffected thalamus...

..Follow-up examinations </=2 years later revealed a remaining gliotic lesion...

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..Six months after treatment, MR imaging was normal. No similar case of perichondritis with involvement of the lumbar region could be found in the current literature...

..9 ppm, and lactic acid in the initial examination. After 3 months, NAA returned to normal, and lactic acid disappeared. The methyl resonance of branched chain amino acids, however, remained...

..1H-MR spectroscopy was helpful in excluding an intra-axial neoplasm with exophytic growth, mainly due to the absence of creatine and N-acetyl aspartate peaks, and markedly elevated choline peak...

..Such clefts are extremely rare, and there is only 1 previous report in the literature...

..Among the studied variables, IPA, Tp, and IPD were particularly useful in differentiating patients from healthy subjects (probability reaching 93%)...

..Follow-up MR imaging performed 16 days later revealed disappearance of white matter lesions, suggesting that during the acute stage of carbon monoxide poisoning, white matter can be more sensitive than gray matter to ischemia...

..14-1.60 x 10(-3) mm(2)/s) compared with those in normal-appearing brain tissue (0.65-1.00 x 10(-3) mm(2)/s) and subtle high signal intensity characteristics on diffusion-weighted images obtained at b = 1000 s/mm(2)...

..We present the case of widespread leptomeningeal lesions secondary to a malignant mesothelioma in a 61-year-old woman...

..The fourth ventricle showed cystic dilatation associated with an enlarged posterior fossa, characteristic for Dandy-Walker malformation. These findings suggest that rhombencephalosynapsis and Dandy-Walker malformation can coexist...