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1.
Magn Reson Med Sci ; 16(4): 325-331, 2017 Oct 10.
Article in English | MEDLINE | ID: mdl-28202853

ABSTRACT

PURPOSE: Although the neonatal and infantile brain typically shows sequential T1 shortening according to gestational age as a result of myelination, several structures do not follow this rule. We evaluated the relationship between the signal intensity of various structures in the neonatal and infantile brain on T1-weighted imaging (T1WI) and either postnatal or gestational age. MATERIALS AND METHODS: We examined magnetic resonance images from 120 newborns and infants without any abnormalities in the central nervous system. Written informed consent was obtained from all parents and the institutional review board approved the study. Gestational age at examination ranged from 35 weeks, 3 days to 46 weeks, 6 days, and postnatal age ranged from 7 days to 127 days. Signal intensity on T1WI was evaluated on a scale from Grade 1 (indistinguishable from surrounding structures) to Grade 4 (higher than cortex and close to fat). We evaluated relationships between the T1 signal grades of various structures in the neonatal brain and postnatal or gestational age using Spearman's correlation analysis. RESULTS: Significant positive correlations were identified between T1 signal grade and gestational age in the pyramidal tract (P < 0.001). Conversely, significant negative correlations were evident between T1 signal grade and postnatal age (P < 0.001), in structures including the stria medullaris thalami, fornix cerebellar vermis, dentate nucleus and anterior pituitary gland. CONCLUSION: Significant negative correlations exist between signal intensity on T1WI and postnatal age in some structures of the neonatal and infantile brain. Some mechanisms other than myelination might play roles in the course of signal appearance.


Subject(s)
Brain/diagnostic imaging , Brain/physiology , Child Development/physiology , Magnetic Resonance Imaging/methods , Female , Gestational Age , Humans , Infant , Infant, Newborn , Male
2.
Magn Reson Imaging ; 34(7): 896-901, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27109485

ABSTRACT

PURPOSE: The "K2" value is a factor that represents the vascular permeability of tumors and can be calculated from datasets obtained with the dynamic susceptibility contrast (DSC) method. The purpose of the current study was to correlate K2 with Ktrans, which is a well-established permeability parameter obtained with the dynamic contrast enhance (DCE) method, and determine the usefulness of K2 for glioma grading with histogram analysis. METHODS: The subjects were 22 glioma patients (Grade II: 5, III: 6, IV: 11) who underwent DSC studies, including eight patients in which both DSC and DCE studies were performed on separate days within 10days. We performed histogram analysis of regions of interest of the tumors and acquired 20th percentile values for leakage-corrected cerebral blood volume (rCBV20%ile), K2 (K220%ile), and for patients who underwent a DCE study, Ktrans (Ktrans20%ile). We evaluated the correlation between K220%ile and Ktrans20%ile and the statistical difference between rCBV20%ile and K220%ile. RESULTS: We found a statistically significant correlation between K220%ile and Ktrans20%ile (r=0.717, p<0.05). rCBV20%ile showed a significant difference between Grades II and III and between Grades II and IV, whereas K220%ile showed a statistically significant (p<0.05) difference between Grades II and IV and between Grades III and IV. CONCLUSIONS: The K2 value calculated from the DSC dataset, which can be obtained with a short acquisition time, showed a correlation with Ktrans obtained with the DCE method and may be useful for glioma grading when analyzed with histogram analysis.


Subject(s)
Brain Neoplasms/blood supply , Brain Neoplasms/diagnostic imaging , Capillary Permeability/physiology , Cerebral Blood Volume/physiology , Contrast Media , Glioma/blood supply , Glioma/diagnosis , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Adolescent , Adult , Aged , Aged, 80 and over , Brain Neoplasms/pathology , Female , Glioma/pathology , Humans , Male , Middle Aged , Neoplasm Grading , Statistics as Topic , Young Adult
3.
J Comput Assist Tomogr ; 40(2): 297-300, 2016.
Article in English | MEDLINE | ID: mdl-26571060

ABSTRACT

OBJECTIVE: This study aimed to assess the utility of dural thickening of the internal auditory canal (IAC) in patients with spontaneous intracranial hypotension (SIH) syndrome and determined the sensitivity and specificity of this image finding. METHODS: Magnetic resonance images were evaluated for 22 cases of definite SIH and 16 cases of unlikely SIH. On contrast-enhanced magnetic resonance imaging, pachymeningeal enhancement and dural thickening of the IAC were assessed. RESULTS: Pachymeningeal enhancement was observed in 21 of 22 patients in the definite SIH group and 1 of 16 patients in the unlikely SIH group (sensitivity, 95.5%; specificity, 93.8%). Dural thickening of the IAC was observed in 15 of 22 patients in the definite SIH group and 0 of 16 patients in the unlikely SIH group (sensitivity, 68.2%; specificity, 100%). CONCLUSIONS: Dural thickening of the IAC showed 100% specificity for SIH syndrome and can increase the accuracy of diagnosis of SIH syndrome.


Subject(s)
Dura Mater/pathology , Ear, Inner/pathology , Intracranial Hypotension/pathology , Magnetic Resonance Imaging , Adolescent , Adult , Aged , Contrast Media , Female , Humans , Image Enhancement , Male , Middle Aged , Sensitivity and Specificity , Syndrome , Young Adult
4.
Jpn J Radiol ; 33(4): 210-5, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25749832

ABSTRACT

PURPOSE: To investigate morphological changes of the superior and middle cerebellar peduncles (SCP, MCP) in spinocerebellar degeneration (SCD) by observing "cerebellar peduncle quarter notes". MATERIALS AND METHODS: We examined 21 patients with SCD, including nine patients with multiple system atrophy cerebellar type (MSA-C), and 24 controls. We measured SCP angle and performed diffusion tensor analysis to quantify the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of the MCP. We quantified the relationship between SCP angle and the ADC and FA of the MCP, and compared these variables between MSA-C patients and controls. RESULTS: There was statistically significant negative correlation between SCP angle and FA of the MCP, and a positive correlation between SCP angle and the ADC of the MCP. Mean SCP angle was larger among MSA-C patients than among normal controls. CONCLUSIONS: SCP angle tended to be larger among patients with severe degeneration of the MCP. The SCP angle, quantified by observing "cerebellar peduncle quarter notes", may be a simple index for evaluation of degeneration of the MCP.


Subject(s)
Diffusion Tensor Imaging , Middle Cerebellar Peduncle/pathology , Spinocerebellar Degenerations/pathology , Adult , Aged , Anisotropy , Case-Control Studies , Feasibility Studies , Female , Humans , Image Interpretation, Computer-Assisted , Male , Middle Aged
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