Yazar "Erdal H.H." seçeneğine göre listele

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    Magnetic resonance spectroscopy of the thalamus in essential tremor patients
    (2005) Kendi A.T.K.; Tan F.U.; Kendi M.; Erdal H.H.; Tellioğlu S.
    Background and Purpose. Although essential tremor (ET) is one of the most common movement disorders, its pathogenesis remains obscure. The ventral intermediate nucleus of the thalamus (VIM nucleus) is suggested to play an important role in the occurrence of disease. In this study, the authors investigated the presence of biochemical or metabolic alterations in the thalamus of patients with ET using magnetic resonance (MR) spectroscopy. Methods. The study group included 14 patients with ET who suffered from tremor predominantly in their right arm and 9 healthy controls. All patients and controls were right handed. Following conventional cranial MR imaging, single voxel proton MR spectroscopy of the thalamus involving the VIM nuclei was performed bilaterally in both the patients with ET and controls. Metabolite peaks of choline (Cho), creatine (Cr), and N-acetylaspartate (NAA) were obtained from each spectroscopic volume of interest. The right and left thalamic NAA/Cr and Cho/Cr ratios were compared first within the patient group and then between the control and patient groups. The differences in age and spectroscopic data between groups were assessed using the Mann-Whitney U test, whereas the comparison within groups between left thalamus and right thalamus was done by the Wilcoxon test. Results. In patients with ET, the NAA/Cr ratio of the right thalamus was found to be significantly higher than the NAA/Cr ratio of the left thalamus (P = .02). However, NAA/Cr and Cho/Cr ratios were found to be similar (P > .05) when we compared the control and patient groups for the right thalamus and then the left thalamus. Conclusion. These data present preliminary evidence for metabolic alterations of the contralateral thalamus (namely, low NAA/Cr ratio) in ET patients with predominantly involved right arm. However, the series is small and further data are necessary to clear the subject adequately. Copyright © 2005 by the American Society of Neuroimaging.
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    MR spectroscopy of cervical spinal cord in patients with clinical and/or electrophysiologic signs of spinal cord compression
    (Centauro SRL, 2006) Kendi A.T.K.; Bademci G.; Kara S.A.; Keskil S.; Erdal H.H.
    We evaluated the efficiency of MR spectroscopy compared with conventional MR imaging in 14 patients with clinical and/or electrophysiologic signs of spinal cord compression. Cervical spinal cord was evaluated for the presence of abnormal signal intensity on T1 and T2 weighted images. MR spectroscopy was performed at the level of spinal cord compression seen on conventional MR images. Clinical and/or electrophysiological studies were also obtained to confirm the presence of a suspected spinal cord compression for these areas. MR spectroscopy was also performed at a normal site of spinal cord without any clinical and/or electrophysiological finding of compression and without any sign of compression on conventional MR images. MR spectroscopy findings of suspected areas were compared with the normal areas for each patient. Twenty levels of cervical spinal cord with both clinical and/or electrophysiological and conventional MR signs of compression were evaluated with MR spectroscopy. MR spectroscopy was also performed at the normal areas of the cervical spinal cord selected adjacent to the level of compression as vascularity and metabolism of cervical spinal cord significantly change between different levels. All patients except one had a decrease in N-acetylaspartate level at the suspected areas compared to the normal areas without any sign or suspicion of compression. Creatine levels were increased in 14 suspected area but decreased in six. Choline levels were decreased in 12 and increased in eight levels. Lactate levels were increased at eight levels and decreased in 12 levels. MR spectroscopy of the spinal cord can yield results supporting both clinical and electrophysiological evaluation. MR spectroscopy of the spinal cord at the level of compression observed on conventional MR images can support neuronal loss and disruption of axonal integrity.
  • Küçük Resim
    Öğe
    Transient arterial enhancement in a hepatic peritumoral fat-spared area
    (2005) Ünal B.; Bilgili Y.; Kara S.; Erdal H.H.
    Early-enhancing areas that are perfusion abnormalities rather than tumor deposit are sometimes encountered on arterial dominant-phase images in multisection dynamic magnetic resonance imaging. Focal sparing in diffusely fatty liver is also a well recognized entity. However, both conditions occasionally create problems in the diagnosis of hepatic mass lesions. Familiarity with these abnormalities on ultrasonography and multisection dynamic magnetic resonance images is important to prevent misinterpretation of these pseudolesions as real masses. In addition, focal sparing can be the only clue for a space occupying lesion in the liver. We present here the ultrasonography and magnetic resonance imaging findings of a case with liver metastasis from pancreas cancer which caused a wedge-shaped fat-spared enhancing area on dynamic magnetic resonance imaging. © Turkish Society of Radiology 2005.