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Biomedical subjects

R Nuri Sener

Publications and source records attributed to R Nuri Sener.

At least 19 recordsLinked to original sources
PubMed2007

Maple syrup urine disease: diffusion MRI, and proton MR spectroscopy findings.

A 7-month-old boy is reported with acute metabolic crisis of maple syrup urine disease. A reversible intramyelinic type of edema was noted by diffusion MRI which completely resolved in 3 months in accordance with good clinical outcome. Proton MR spectroscopy revealed decreased NAA, and presence of methyl resonances of branched chain amino acids at 0.9 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.

Diffusion Magnetic Resonance Imaging↗
PubMed2006

Malignant peripheral nerve sheath tumor of the oculomotor nerve.

We present the short-term follow-up magnetic resonance (MR) studies and 1H-MR spectroscopy in a child with malignant peripheral nerve sheath tumor of the oculomotor nerve associated with other less aggressive cranial nerve schwannomas. The tumor revealed perineural extension and diffuse nerve involvement besides rapid growth. 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.

Aspartic Acid↗
PubMed2004

Subacute sclerosing panencephalitis findings at MR imaging, diffusion MR imaging, and proton MR spectroscopy.

A case of subacute sclerosing panencephalitis in a 2-year-old boy is reported. In addition to asymmetric lesions in the parietotemporal lobes, right thalamus, and globus pallidus, symmetric patterns were notable in the brain stem, middle cerebellar pedincles, and dentate nuclei. Proton MR spectroscopy revealed markedly decreased N-acetylaspartate peaks and normal choline and myo-inositol levels in the lesions. Diffusion MR imaging revealed an elevated diffusion pattern manifested with high apparent diffusion coefficient values (1.14-1.60 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).

Child, Preschool↗
PubMed2004

Leptomeningeal metastasis from malignant pleural mesothelioma.

Leptomeningeal metastasis from malignant mesothelioma is very rare; to our knowledge, only one imaging report exists in the literature. We present the case of widespread leptomeningeal lesions secondary to a malignant mesothelioma in a 61-year-old woman.

Cerebellum↗
PubMed2004

Diffusion-weighted and conventional MR imaging findings of neuroaxonal dystrophy.

BACKGROUND AND PURPOSE: Neuroaxonal dystrophy is a rare progressive disorder of childhood characterized by mental deterioration and seizures. The diffusion-weighted and conventional MR imaging findings are reported for six cases. METHODS: Six patients aged 19 months to 9 years with proved neuroaxonal dystrophy (one with the infantile form, five juvenile forms) underwent imaging at 1.5 T. Echo-planar diffusion-weighted images were acquired with a trace imaging sequence in five patients and with a three-gradient protocol (4000/110) in one. Images obtained with a b value of 1000 s/mm2 and corresponding apparent diffusion coefficient (ADC) maps were studied. ADCs from lesion sites and normal regions (pons and temporal and occipital lobes) were evaluated. RESULTS: A hyperintense cerebellum (a characteristic of the disease) was evident on fluid-attenuated inversion recovery images in all cases. Four patients had associated cerebral changes. Diffusion-weighted images, especially ADC maps, showed an elevated diffusion pattern in the cerebellum in the five juvenile cases (normal images at b = 1000 s/mm2, ADCs of 1.30-2.60 x 10(-3) mm2/s). A restricted diffusion pattern was evident in the infantile case (hyperintensity at b = 1000 s/mm2, low ADCs of 0.44-0.55 x 10(-3) mm2/s). ADCs were normal in the pons and temporal and occipital lobes (0.64-1.00 x 10(-3) mm2/s). CONCLUSION: An elevated cerebellar diffusion pattern is a predominant feature of juvenile neuroaxonal dystrophy. Coexistent elevated and restricted diffusion patterns were evident in different brain regions in different forms of the disease. Dystrophic axons likely account the restricted diffusion, whereas spheroid formation (swelling) and abnormal myelination result in elevated diffusion.

Biopsy↗
PubMed2003

Epidural, paraspinal, and subcutaneous lipomatosis.

A unique case of idiopathic diffuse lipomatosis is reported. The patient was an 11-year-old boy with diffuse lipomatosis in the epidural space, paraspinal muscles, and thoracolumbar subcutaneous regions. Epidural lipomatosis involved the entire thoracolumbar spine and was associated with filar thickening and lipoma. In addition, paraspinal muscles, especially the erector spinae group, had diffuse fatty infiltration. The ultimate clinical effect of this fatty tissue was urinary dysfunction, radicular pain and hypoesthesia in both legs and difficulty walking.

Child↗
PubMed2003

Acute carbon monoxide poisoning: diffusion MR imaging findings.

During the acute stage of carbon monoxide poisoning, diffusion MR images obtained at b=1000 s/mm2 revealed high signal intensity lesions in the white matter, consistent with restricted diffusion. Low apparent diffusion coefficient values (0.18-0.34 x 10(-3) mm2/s) were noted in the affected white matter regions. 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.

Acute Disease↗
PubMed2003

Neuro-Behcet's disease: diffusion MR imaging and proton MR spectroscopy.

We herein report the case of a 53-year-old woman with Behcet's disease and an acute T2-hyperintense lesion in left side of the pons. Echo-planar "trace" diffusion MR imaging revealed high signal intensity changes at the lesion site on b = 1000 s/mm(2) images, initially suggesting restricted diffusion. On corresponding apparent diffusion coefficient maps, however, the lesion had high signal intensity and high apparent diffusion coefficient values (1.22 x 10(-3) mm(2)/s), compared with the contralateral normal side of the pons (0.86 x 10(-3) mm(2)/s) and compared with the normal temporal white matter (0.80 x 10(-3) mm(2)/s). This was consistent with the presence of increased diffusion, hence vasogenic edema. Proton MR spectroscopy excluded acute infarction. This particular pattern (high signal intensity on b = 1000 s/mm(2) images in association with high apparent diffusion coefficient values) likely represented the acute inflammatory process associated with disrupted brain-blood barrier in the fulminant form of neuro-Behcet's disease. Follow-up examinations </=2 years later revealed a remaining gliotic lesion.

Behcet Syndrome↗
PubMed2003

Pantothenate kinase-associated neurodegeneration: MR imaging, proton MR spectroscopy, and diffusion MR imaging findings.

We herein report the case of a 15-year-old male patient with pantothenate kinase-associated neurodegeneration. The classic "eye-of-the-tiger" appearance was initially present on the globus pallidi on T2-weighted MR images and had disappeared by the time of the 10-month follow-up examination. Fluid-attenuated inversion recovery images revealed marked hypointensity in the globus pallidi and dentate nuclei and high signal intensity changes in the deep cerebral white matter. Proton MR spectroscopy revealed markedly decreased N-acetylaspartate in the globus pallidi, associated with decreased N-acetylaspartate and increased myoinositol in the deep cerebral white matter. Diffusion MR images (b=1000 s/mm(2)) were negative (normal appearing) for deep cerebral white matter lesions, whereas apparent diffusion coefficient values were slightly increased (1.08-1.12 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.

Adolescent↗
PubMed2002

Metachromatic leukodystrophy: diffusion MR imaging findings.

Herein the case of a 10-month-old boy with metachromatic leukodystrophy is reported. Diffusion MR imaging performed with an echo-planar trace sequence revealed a cytotoxic edema-like pattern (high signal intensity on b = 1000 s/mm(2) images and low apparent diffusion coefficient values) in the affected white matter in the absence of an ischemic condition. This finding was unchanged at a 6-month follow-up, as revealed by diffusion MR imaging. A gradient-echo diffusion sequence, reverse fast imaging in steady-state precession, revealed hyperintense changes at the corresponding regions. It is likely that the cytotoxic edematous pattern (restricted diffusion pattern) reflected restriction of mobility of the water molecules within abnormal portions of the myelin sheath, because impaired myelin breakdown and reutilization are known features of metachromatic leukodystrophy.

Diffusion Magnetic Resonance Imaging↗
PubMedDate not supplied

Canavan disease: diffusion magnetic resonance imaging findings.

A 15-month-old boy with Canavan disease is reported in whom a restricted diffusion pattern on diffusion magnetic resonance imaging (MRI) (high signal on b = 1,000 mm2/s images and low apparent diffusion coefficient [ADC] values) was evident in the affected regions of the brain, including the peripheral white matter, globi pallidi, thalami, brainstem, dorsal pons, and dentate nuclei. The ADC values at these regions ranged from 0.42 to 0.56 x 10(-3) mm2/s compared with the normal ADC values from the uninvolved deep frontal white matter (0.68-0.92 x 10(-3) mm2/s). The known histopathologic features in Canavan disease include edematous and gelatinous brain tissue associated with diffuse vacuolization. Considering these and the diffusion MRI findings in this patient, it is likely that existence of a gel (gelatinous) state rather than the usual sol state of water molecules in the affected brain regions accounted for the restricted diffusion pattern in Canavan disease.

Brain↗
PubMedDate not supplied

Diffusion magnetic resonance imaging in infantile neuroaxonal dystrophy.

A 7-month-old girl with infantile neuroaxonal dystrophy is reported. In diffusion MRI, the pyramidal tracts and dentate nuclei had high signal on b = 1,000 s/mm2 images and low apparent diffusion coefficient (ADC) values. This pattern likely reflected the presence of abnormal (dystrophic) axons with restricted mobility of water molecules. A reverse pattern was evident in the cerebellar cortex with high ADC values. This was likely a reflection of dysmyelination or lack of myelination.

Brain↗
PubMedDate not supplied

L-2 hydroxyglutaric aciduria: proton magnetic resonance spectroscopy and diffusion magnetic resonance imaging findings.

A 10-month-old boy was reported with the diagnosis of L-2 hydroxyglutaric aciduria. Amino acid chromatographic analysis revealed an 80-fold increase of hydroxyglutaric acid in the urine. Proton magnetic resonance (MR) spectroscopy of the brain obtained with the hybrid chemical shift imaging sequence (repetition time = 1,500 milliseconds, echo time = 40 milliseconds) revealed prominent peaks resonating at 2.50 ppm, which were attributable to L-2 hydroxyglutaric acid. Diffusion MR imaging was obtained using the echo-planar trace sequence (repetition time = 5,700 milliseconds, echo time = 139 milliseconds). Two different diffusion patterns were evident: a restricted diffusion pattern in the globi pallidi and an increased diffusion pattern in the white matter.

Brain↗
PubMedDate not supplied

Diffusion magnetic resonance imaging of solid vestibular schwannomas.

Six patients with solid vestibular schwannomas were studied by diffusion magnetic resonance imaging to assess if this modality adds new information for these tumors, because there is no previous report in the relevant literature. The sizes of the tumors ranged from 2.2 to 4.7 cm with respect to their largest diameters. They were isointense to the normal brain parenchyma on b = 1,000 s/mm2 images. The apparent diffusion coefficient (ADC) values in the tumors were high (range: 1.14-1.72 x 10(-3) mm2/s, mean = 1.42 +/- 0.17 x 10(-3) mm2/s) compared with normal brain parenchyma ADC values (mean = 0.80 +/- 0.11 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.

Adult↗
PubMedDate not supplied

Nonketotic hyperglycinemia: diffusion magnetic resonance imaging findings.

We report about a boy with nonketotic hyperglycinemia who was studied at 15 days of life with a follow-up examination at age 6 months. Magnetic resonance (MR) imaging revealed progressive atrophy, callosal thinning, and delayed myelination. Glycine peaks were shown by proton MR spectroscopy at 3.56 ppm with a long echo time (TE, 135 milliseconds; TR, 1500 milliseconds). Echo-planar diffusion MR imaging (TR, 5700 milliseconds; TE, 139 milliseconds) at 15 days of life revealed high-signal lesions in the pyramidal tracts, middle cerebellar pedicles, and dentate nuclei on b = 1000 s/mm2 images associated with low apparent diffusion coefficient (ADC) values. By age 6 months, the lesions became more prominent on b = 1000 s/mm2 images with lower ADC values. 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.

Atrophy↗
PubMedDate not supplied

Phenylketonuria: diffusion magnetic resonance imaging and proton magnetic resonance spectroscopy.

Two patients with phenylketonuria are reported with white matter lesions. Diffusion magnetic resonance (MR) imaging revealed restricted diffusion patterns (high signal) on b = 1000 s/mm2 images associated with low apparent diffusion coefficient values ranging between 0.44 x 10-3 mm2/s and 0.56 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.

Adult↗