Evaluation of lumbar intervertebral disc degeneration with synthetic MRI / 中华放射学杂志

Objective:To investigate the value of synthetic MRI for evaluating lumbar intervertebral disc degeneration.Methods:A total of 414 lumbar intervertebral discs from 85 patients were included prospectively from September 2018 to February 2019 in First Affiliated Hospital of China Medical University. The T 1, T 2 and proton density (PD) mapping were generated from synthetic MRI. Two doctors measured the T 1, T 2 and PD values to evaluate intraobserver agreement by using ICC. For Pfirrmann grade comparisons, the variables with normal distribution were analyzed with the one-way analysis of variance, whereas those with skewed distribution were analyzed with the Kruskal-Wallis H test. Furthermore, the ROC curves were used on significant parameters to evaluate their diagnostic efficacy. The Z test was used to compare the differences of area under the ROC curves (AUC). Results:The color of the quantitative mapping changed along with the increase of the Pfirrmann grade of the intervertebral discs, which corresponded to the decrease of the T 2WI signal intensity. The ICC values of the quantitative values of nucleus pulposus indicated excellent agreement (ICC>0.900), followed by anterior annulus fibrosus (ICC>0.700) and then the posterior annulus fibrosus (ICC>0.600). The results of the adjacent Pfirrmann grade comparisons were as follows: between Pfirrmann grade Ⅰ and Ⅱ, the differences of T 2 and PD values of nucleus pulposus were statistically significant ( P=0.004 and P<0.001, respectively); between Pfirrmann grade Ⅱ and Ⅲ, the differences of T 1, T 2 and PD values of nucleus pulposus were statistically significant (all P<0.001); between Pfirrmann grade Ⅲ to Ⅳ, the T 1, T 2 and PD values of nucleus pulposus (all P<0.001) and the T 1 and PD values of posterior annulus fibrosus ( P=0.025, P<0.001, respectively) had statistically significant differences; between Pfirrmann grade Ⅳ to Ⅴ, the difference of T 2 values of nucleus pulposus were statistically significant ( P=0.031). The AUC of T 2 values of nucleus pulposus between Pfirrmann grade Ⅱ to Ⅲ and grade Ⅳ to V were higher than those of the PD values ( Z=2.443, 3.591 and P=0.015,<0.001). Conclusions:Synthetic MRI can quantitatively evaluate lumbar disc degeneration, in which the T 2 value of nucleus pulposus may be the most effective parameter with high repeatability.

Spontaneous Regional Brain Activity in Healthy Individuals is Nonlinearly Modulated by the Interaction of ZNF804A rs1344706 and COMT rs4680 Polymorphisms / 神经科学通报·英文版

ZNF804A rs1344706 has been identified as one of the risk genes for schizophrenia. However, the neural mechanisms underlying this association are unknown. Given that ZNF804A upregulates the expression of COMT, we hypothesized that ZNF804A may influence brain activity by interacting with COMT. Here, we genotyped ZNF804A rs1344706 and COMT rs4680 in 218 healthy Chinese participants. Amplitudes of low-frequency fluctuations (ALFFs) were applied to analyze the main and interaction effects of ZNF804A rs1344706 and COMT rs4680. The ALFFs of the bilateral dorsolateral prefrontal cortex showed a significant ZNF804A rs1344706 × COMT rs4680 interaction, manifesting as a U-shaped modulation, presumably by dopamine signaling. Significant main effects were also found. These findings suggest that ZNF804A affects the resting-state functional activation by interacting with COMT, and may improve our understanding of the neurobiological effects of ZNF804A and its association with schizophrenia.

Application of 3.0T Dynamic Contrast-enhanced MRI in the Grading of Gliomas / 中国医科大学学报

Objective To explore the clinical significance of 3.0T dynamic?contrast enhanced MRI scan in the grading of intracranial glioma. Methods The magnetic resonance examination were performed in 40 cases of patients of brain tumors confirmed by surgery pathology(29 pa?tients with glioma),including conventional MRI and dynamic contrast?enhanced MRI. Using Kinetic Modeling?version 3.0 software on the GE 3.0T magnetic resonance workstation calculation of intracranial tumor parenchyma area corresponding quantitative parameters Ktrans and Ve values. The quantitative parameters between any two classification were compared ,and the difference was statistically analyzed. The characteristics of the different level of intracranial glioma's dynamic enhanced scan parameters were preliminary analyzed. The receiver?operating characteristic curve (ROC)analysis of Ktrans value and Ve value was performed,and the diagnosed threshold,sensitivity and specificity were acquired. Results While applying dynamic?contrast enhanced MRI scan acquired Ktrans and Ve values ,both values of high grade gliomas include gradeⅢandⅣwere significantly higher than that of low grade gliomas include gradeⅠandⅡ(P0.05). To identify low grade gliomas with high grade glioma ,Ktrans and Ve diagnosis threshold was 0.204/min and 0.099 respectively. To distinguish between gradeⅡandⅢglioma,Ktrans and Ve diagnosis threshold was 0.247/min and 0.176 respectively. Conclusion Combining quantitative parameters Ktrans and Ve value that come from 3.0T dynamic con?trast enhanced MRI scan with regular enhancement MRI can distinguish low grade gliomas with high grade gliomas glioma ,as well as distinguish gradeⅡwithⅢglioma;However,it is still difficult to identify low grade gliomaⅠwithⅡ,as well as high grade gliomaⅢwithⅣ. The Ktrans and Ve value plays an important role in discriminate different grade intracranial tumors in a preoperative noninvasive way.

Diffusion tensor MR imaging in the assessment of cognitive functions in children with periventricular leukomalacia / 中华放射学杂志

Objective To investigate the values of diffusion tensor MR imaging(DTI)and fiber tractography(FT)in the assessment of cognitive functions in children with periventricular leukomalacia (PVL),to facilitate to understand the mechanism of PVL children's cognitive functions.Methods Forty six children with PVL and 16 age-matched volunters were recruited.Developmental quotient(DQ)of all cases was recorded.According to the DQ scores,patients were divided into 3 groups:mild in 11 patients,moderate in 19,and severe in 16.DTI was performed in all cases and fractional anisotropy(FA)values were be calculated.Non-paired t test was used to compare the FA values of major white matter fibers between patients group and controls group.One-way ANOVA was used to compare the FA values among 4 groups.Results Compared with controls,all 46 patients with PVL showed a significant mean FA reduction in left corticospinal tract(CST)(0.476 ±0.064 vs.0.531 ±0.064),bilateral anterior limb of internal capsula (ICAL)(left 0.357 ±0.050 vs.0.405 ±0.081,right 0.370 ±0.040 vs.0.405 ±0.036),posterior limb of internal capsule(ICPL)(left 0.483 ±0.044 vs.0.546 ±0.091,right 0.485 ±0.046 vs.0.547 ±0.083),arcuate fasciculus(AF)(left 0.367 ± 0.069 vs.0.433 ± 0.097,right 0.363 ± 0.064 vs.0.421 ±0.091),posterior thalamic radiation(PTR)(left 0.390 ± 0.059 vs.0.459 ± 0.067,right 0.382 ± 0.047 vs.0.446 ± 0.064),anterior CG(ACG)(left 0.362 ± 0.056 vs.0.423 ± 0.057,right 0.345 ± 0.056 vs.0.417 ± 0.080),superior longitudinal fasciculus(SLF)(left 0.323 ± 0.050 vs.0.426 ±0.102,right 0.341 ± 0.056 vs.0.416 ± 0.092)and splenium of the corpus callosum(SCC)(0.535 ±0.090 vs.0.606 ±0.060)(t =2.037-3.745,P ＜0.05).The severity of cognitive impairment companied with decrease of the FA values of all fibers.The FA values of bilateral CST,ICAL,ICPL,left AF,bilateral PTR,ACG,SLF and SCC were significantly different among different groups(F =3.021-7.146,P ＜ 0.05).Conclusions The damage widespread of white matter bundles is found in children with PVL DTI and FT can provide details in the assessment of cognitive impairment in children with PVL.

Assessment of Cortical Visual Impairment in Infants with Periventricular Leukomalacia: a Pilot Event-Related fMRI Study

OBJECTIVE: We wanted to investigate the usefulness of event-related (ER) functional MRI (fMRI) for the assessment of cortical visual impairment in infants with periventricular leukomalacia (PVL). MATERIALS AND METHODS: FMRI data were collected from 24 infants who suffered from PVL and from 12 age-matched normal controls. Slow ER fMRI was performed using a 3.0T MR scanner while visual stimuli were being presented. Data analysis was performed using Statistical Parametric Mapping software (SPM2), the SPM toolbox MarsBar was used to analyze the region of interest data, and the time to peak (TTP) of hemodynamic response functions (HRFs) was estimated for the surviving voxels. The number of activated voxels and the TTP values of HRFs were compared. Pearson correlation analysis was performed to compare visual impairment evaluated by using Teller Acuity Cards (TAC) with the number of activated voxels in the occipital lobes in all patients. RESULTS: In all 12 control infants, the blood oxygenation level-dependent (BOLD) signal was negative and the maximum response was located in the anterior and superior part of the calcarine fissure, and this might correspond to the anterior region of the primary visual cortex (PVC). In contrast, for the 24 cases of PVL, there were no activated pixels in the PVC in four subjects, small and weak activations in six subjects, deviated activations in seven subjects and both small and deviated activations in three subjects. The number of active voxels in the occipital lobe was significantly correlated with the TAC-evaluated visual impairment (p < 0.001). The mean TTP of the HRFs was significantly delayed in the cases of PVL as compared with that of the normal controls. CONCLUSION: Determining the characteristics of both the BOLD response and the ER fMRI activation may play an important role in the cortical visual assessment of infants with PVL.

An event-related functional MRI study on working memory impairment in children with primary nocturnal enuresis / 中华放射学杂志

Objective To assess the working memory and explore the activation of brain areas for children with primary nocturnal enuresis (PNE) with fMRI scan. Methods Twenty three right-handed children with PNE and 20 age-matched right-handed healthy children as the controls were recruited.Intelligence tests were performed by means of Wechsler Young Children Scales of Intelligence (C-WISC) in children with PNE and normal controls. The full intelligence quotient (FIQ), verbal IQ (VIQ),performances IQ (PIQ) and the memory/caution (M/C) factor of PNE children and the controls were measured. After Intelligence tests, an enent-related fMRI scan was performed using the categorial N-Back working memory task. Percent of correct responses (PCR) and mean reaction time to correct response (mRT) were recorded and analyzed by the student t test. The fMRI data were analyzed using Statistical Parametric Mapping 2 (SPM2), the differences in activation were compared between two groups. Results The data of 15 PNE children and 15 healthy children were evaluated. The FIQ, VIQ and PIQ in PNE group were in a normal range and no statistical significance with the control group ( P ＞ 0. 05). M/C factor in the PNE group(90.4 ±10.2)was significantly lower than that in the control group (99. 6 ± 11.9) (t =2. 260,P ＜ 0. 05). In the N-Back test, PNE children had significantly less PCR [(72.7±6.3 ) % vs. ( 86. 3 ±6. 7) %, t = 5. 727,P ＜ 0. 01] and longer mRT [ (625. 8 ± 72.5) ms vs. (534. 8 ± 63. 3 ) ms, t = 3. 684,P ＜ 0.01] than the healthy controls. The activation regions of PNE patients and healthy children were mainly in the dorsal right frontal lobe, right parietal lobe, left temporal lobe gyrus fusiformis and bilateral cerebellum posterior lobe. The activation level in left posterior cerebellar lobe in PNE children was significant lower than that in healthy controls (P＜0.01). Conclusion The children with PNE have deficits in working memory which might be associated with the dysfunction of the left cerebellum.

MRI findings of brain damage due to neonatal hypoglycemia / 中华放射学杂志

Objective To report the MRI findings of brain damage obsenrved in neonatal patients who suffered from isolated hypoglycemia and to explore the value of diffusion-weighted imaging(DWI) inearly detection of neonatal hypoglycemic brain iniun,. Methods Twelve neonates with isolated hypoglycemia(10 of the 12 were diagnosed to suffer from hypoglycemic encephalopathy)were enrolled in this study.They were first scanned at age from 3 days to 10 days with Tl WI,T,WI and DWI(b is 0 s/mm2,1000 s/mm2),and 4 of them were then scanned from 7 days to 10 days following the initial scan.All acquired MR images were retrospectively analysed.Results First series of DWl images showed distinct hyperintense signal in 11 cases in several areas including bi lateral occipital cortex(2 cases),right occipital cortex(1 case),left occipital cortex and subcortical white matter(1 case),biIateral occipital cortex and flubcortical white matter(2 cases),bilateral parieto-occipital cortex(2 cases),bilateral parieto-occipital cortex and subcortical white matter(2 cases),the splenium of corpus catlosum(4 cases),bilateral corona radiata(2 cases),left eaudate nucleus and globus pallidus(1 case),bilateral thalamus(1 case),bilaterally posterior limb of internal capsule(1 ease).In the initial T1 WI and T2,WI images,there were subtle hypointensity in the damaged cortical areas(3 cases),hyperintensity in the bilaterally affected occipital cortex(1 case)on T1 weighted images,and hyperintensity in the affected cortex and subcortieal white matter with poor differentiation on T2 weighted images.The followed-up MRI of 4 cases showed regional encephalomalaeia in the affected occipital lobes(4 cases),slightly hyperintensity on T2 weighted images in the damaged occipital cortex(2 cases),extensive demyelination(1 case).disappearance of hyperintensity of the splenium of corpus callosum(1 case),and persistent hyperintensity in the splenium of corpus callosum (1 case)on T2 weighted images.Conclusion The findings suggest that posterior parieto-occipital regions are most frequently injured in neonatal period due to severe hypoglycemia.DWI is a useful technique in the early detection and evaluation of hypoglycemic brain injury of neonates.

Combination of fMRI and DTI in the Assessment of Cortical Visual Impairment in the Children with Periventricular Leukomalacia / 中国医学影像学杂志

Purpose:To investigate fMRI and DTI in the assessment of cortical visual impairment in children with periventricular leukom-alacia ( PVL).Materials and Methods: Twenty-four children with PVL were enrolled.Meanwhile,24 age-matched normal controls were recruited for comparison.fMRI scan was performed using a 3.0T MR scanner.Data analysis was performed by statistical parametric mapping software (SPM2).Activated voxels were identified in both groups,t test was used for statistical analysis.DTI was performed by MedlNRIA software and DTI color maps were created from fractional anisotropy (FA) values and the three vector elements,FA values on diffusion tensor color maps were compared between the patients and the controls.AH the FA values of these WM fibers were analyzed by paired t test.The correlation was calculated between FA values and activated voxels of visual cortex for PVL children using SPSS10.0.Results: In all 24 normal children,the maximum response of blood oxygen level-dependent (BOLD) signal was located in the primary visual cortex ( PVC).However,some of the 24 cases of PVL had deviated activation.The active voxels of patients in visual cortex were less than that of controls.All 24 cases of PVL showed a significant mean FA reduction in ICPL and PTR in comparison to the ipsilateral regions of healthy controls.The significantly positive correlation was shown between FA values and activated voxels of visual cortex for PVL children.Conclusion:fMRI and DTI play an important role in the assessment of cortical visual impairment in children with PVL.

The Clinical Imaging Performances of Solitary Plasmacytoma of Spine / 中国医学影像学杂志

Purpose:Analysing the imaging performance of solitary plasmacytoma of spine,to raise the awareness and the diagnosis accuracy.Materials and Methods: Five cases of spinal solitary plasmacytoma confirmed by clinical pathology were retrospectively analysed,to sum up the imaging performance characteristics.Results: All lesions were single vertebra involved,3 cases in thoracic and 2 cases in lumbar,3 cases occurred vertebral compression fracture.X-ray and CT showed osteolytic destruction,expansive growth and soft tissue mass,MRI showed diversity of signals,and remarkable enhancement after contrast injection.Conclusions: X-ray presents lower diagnostic sensitivity,but contributes to exclude multiple myeloma.CT and MRI can depict the morphological features and extent of tumor regions definitely,CT shows better than MRI on the thickening trabecula and residual bone in the tumor,MRI can provide a lot of information for plasmacytoma,including the diagnosis,identification and staging,which is considered as the best imaging diagnostic methods of plasmacytoma.

Progress in the study of the chemical synapse in glioma-associated epileptogenesis / 北京大学学报(医学版)

Seizures may be the first or sometimes the only manifestation of patients with glioma in clinics. The aim of operation is to eliminate epilepsy far beyond mere resection of tumor mass. The underlyling mechanisms of glioma-associated epileptogenesis are poorly understood. Recently the theory of amino-acid like neurotransmitters in chemical synapse is gradually accepted. However, the molecular mechanisms remain to be further investigated on how glutamate release is regulated and how synaptic homeostasis in peripheral neurons is kept or disturbed. So detailed studies are needed to clarify specific molecular target and provide proper evidence for optimal antiepileptic drugs in glioma-associated epileptoge-nesis.

Quantitative study of MR T1 and T2 relaxation times and 1HMRS in gray matter of normal adult brain / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate magnetic resonance (MR) Imaging and (1)H magnetic resonance spectroscopy ((1)HMRS) in the study of normal biochemical process of the brain, as well as differentiation of normal senile brain from cerebral diseases related to senility.</p><p><b>METHODS</b>One hundred and eighty healthy adult volunteers were selected for MR examination and 60 other healthy subjects for (1)HMRS examination. Ages of subjects ranged from 18 to 80 years. They were divided into six age groups. A 0.35 T superconductive MR system was used to perform MR examination. Point resolved spectroscopy sequence was required for (1)HMRS. The metabolites in the spectra included: N-acetylaspartate (NAA), choline compounds (CHO), creatine compounds (CR), myo-inositol (MI), glutamate and glutamine (Glu-n).</p><p><b>RESULTS</b>In 180 cases of MR, the shortest T(2) relaxation time occurred in the deep gray matter within the same age group while the length of T(1) relaxation time was ordered from low to high compared to age groups. T(2) relaxation time decreased as age increased. The peaks, ordered from high to low, were as follows in 60 cases of (1)HMRS: NAA, CR, CHO, MI, Glu-n. The ratios of NAA/CR and Glu-n/CR were higher in the senile age group, while that of MI/CR was lower. The ratio of CHO/CR was increased as age decreased. The ratio of NAA/CR and MI/CR gradually decreased in relation to movement from the anterior to the posterior part of the brain; the ratio of CHO/CR was highest in the occipital cortex. Correlation of T(1) relaxation time and partial metabolite ratios to age were present in gray matter.</p><p><b>CONCLUSIONS</b>Quantitative studies of MR T(1) and T(2) relaxation times and (1)HMRS are essential to evaluation of normal myelinization processes, neuronal integrity and age-related biochemical changes in the brain.</p>

Experimental Investigation of Correlation Between MSCT Perfusion and Blood Lipid in Steroid-induced Avascular Necrosis of Femoral Head / 实用放射学杂志

Objective To explore the correlation between change of blood lipid and MSCT perfusion imaging in steroid-induced femoral head necrosis in adult rabbits.Methods 20 rabbits 1~1.5 years old in age were divided into two group:16 rabbits in experimental group,8 mg/kg Methylprednisolone was injected twice a week;4 rabbits were used as control group.At 2,4,6,8 week after injection,4 rabbits in experimental group and 1 rabbit in contral group were killed respectively.Before killing the rabbits,the blood lipid was examined and MSCT perfusion imaging was done and the correlation between them was analysed.The index of TRIG,CHOL,Perfusion,PEI,TTP,MTT.All femoral heads were undergone pathological investigation.Results Two weeks after injection,blood lipid began increasing,then blood flow of femoral head decreasing obviously with prolongation of injection;PEI and MTT decrease only 4 weeks after injection.There were a negaitive correlation between blood lipid and blood flow of femoral head.Conclusion There were obviously correlation between the level of increasing blood lipid and blood flow decreasing in steroid-induced avascular necrosis of femoral head in rabbit.

Quantitative Study of MRI and~1H MRS in Normal Adult Brain / 实用放射学杂志

Objective:To evaluate magnetic resonance imaging(MRI) and 1 H magnetic resonance spectroscopy( 1HMRS)in the study of normal biochemical process of the brain as well as differentiation of normal senile brain from cerebral diseases related to senility.Methods:180 cases of healthy adults were selected to perform MR examination,in which,none of the subjects had the history of neurological and psychotic diseases according to MRI and clinical results.Meanwhile,60 healthy subjects were selected to perform 1 HMRS examination.The ages ranged from 18 to 80 years.They were divided into six age groups purposely.Point resolved spectroscopy sequence was required for 1 HMRS.The metabolites in the spectra included:N-acetylaspartate(NAA),choline compounds(CHO),creatine compounds(CR),myo-inosito(MI),glutamate and glutamine(Glu-n).Results:(1)In 180 cases of MRI,T 2 relation time was lowest in the deep gray matter in the same age group;T 1relation time was in low-high order,while T 2 relation time was decreased with the increase of age in the different age group.(2)The amplitudes in high-to-low order were as follows in 60 cases of 1 HMRS:NAA、CR、CHO、MI、Glu-n.No prominent difference of shape and peak arrangement was seen at the different ipsilateral site in the same age groups;while slight difference at the same site in the different age groups was present.The ratio of NAA/Cr and Glu-n CR was higher in senile age group;while that of MI/Cr was lower.The ratio of CHO/CR was in low-to high order with the difference of age.The ratio of NAA/CR and MI/CR was gradually lower from anterior to posterior part of the brain;the ratio of CHO/CR was highest in occipital cortex however,no definite changing rule was observed in the ration of Glu-n/CR.Correlation of T 1 relation time and partial metabolite ratio with age was present in gray matter.Conclusion:Quantitative study of MRI and 1 HMRS is essential for determination of normal myelinization and neuronal integrity and age-related biochemical changes in the brain.

Usefulness of diffusion-weighted and perfusion-weighted MR in mouse C6 gliomas:correlation with histopathology / 中华放射学杂志

Objective Diffusion/perfusion-weighted MRI (DWI、PWI) was performed to evaluate growth and vascularity of implanted C6 rat gliomas. Methods 36 female Wistar rats were implanted of C6 glioma cells intracerebrally. Between 1 and 4 weeks after implantation, eight to ten different rats were imaged with T_1WI, T_2Weighted imaging, DWI, PWI, and postcontrast T_1WI at each weekly time point. After MRI, each rat brain was examined histologically using HE and immunohistochemical staining for CD34. Results On DWIs, statistical differences of apparent diffusion coefficient (ADC) values for both the solid tumor component and peritumoral region were present comparing 3-4 weeks with 1-2 weeks after implantation (P