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1.
Adv Atmos Sci ; 40(6): 963-974, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36643611

RESUMEN

Changes in ocean heat content (OHC), salinity, and stratification provide critical indicators for changes in Earth's energy and water cycles. These cycles have been profoundly altered due to the emission of greenhouse gasses and other anthropogenic substances by human activities, driving pervasive changes in Earth's climate system. In 2022, the world's oceans, as given by OHC, were again the hottest in the historical record and exceeded the previous 2021 record maximum. According to IAP/CAS data, the 0-2000 m OHC in 2022 exceeded that of 2021 by 10.9 ± 8.3 ZJ (1 Zetta Joules = 1021 Joules); and according to NCEI/NOAA data, by 9.1 ± 8.7 ZJ. Among seven regions, four basins (the North Pacific, North Atlantic, the Mediterranean Sea, and southern oceans) recorded their highest OHC since the 1950s. The salinity-contrast index, a quantification of the "salty gets saltier-fresh gets fresher" pattern, also reached its highest level on record in 2022, implying continued amplification of the global hydrological cycle. Regional OHC and salinity changes in 2022 were dominated by a strong La Niña event. Global upper-ocean stratification continued its increasing trend and was among the top seven in 2022.

2.
Adv Atmos Sci ; 39(3): 373-385, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35035014

RESUMEN

The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content (OHC). Here, we provide the first analysis of recent OHC changes through 2021 from two international groups. The world ocean, in 2021, was the hottest ever recorded by humans, and the 2021 annual OHC value is even higher than last year's record value by 14 ± 11 ZJ (1 zetta J = 1021 J) using the IAP/CAS dataset and by 16 ± 10 ZJ using NCEI/NOAA dataset. The long-term ocean warming is larger in the Atlantic and Southern Oceans than in other regions and is mainly attributed, via climate model simulations, to an increase in anthropogenic greenhouse gas concentrations. The year-to-year variation of OHC is primarily tied to the El Niño-Southern Oscillation (ENSO). In the seven maritime domains of the Indian, Tropical Atlantic, North Atlantic, Northwest Pacific, North Pacific, Southern oceans, and the Mediterranean Sea, robust warming is observed but with distinct inter-annual to decadal variability. Four out of seven domains showed record-high heat content in 2021. The anomalous global and regional ocean warming established in this study should be incorporated into climate risk assessments, adaptation, and mitigation.

3.
Macromol Rapid Commun ; 42(5): e2000600, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33314517

RESUMEN

In order to obtain low-k material with good comprehensive properties, a trifluoromethyl-containing organosiloxane with thermocrosslinkable vinyl and benzocyclobutene groups is designed and synthesized through the Piers-Rubinsztajn reaction. After treating at high temperature, the organosiloxane changed to form a cross-linked polysiloxane (called as c-FSi-BCB). c-FSi-BCB exhibits good dielectric properties with dielectric constant (Dk ) of 2.60 and dielectric loss (Df ) of 1.49 × 10-3 at a high frequency of 5 GHz. Importantly, c-FSi-BCB maintains such good dielectric properties and exhibits low water uptake of below 0.076%, even after immersing it in boiling water for 96 h. c-FSi-BCB also displays good thermostability with a 5% weight loss temperature (T5d ) of 453 °C. These data indicate that this fluorinated organosiloxane is suitable as the matrix resin for the fabrication of devices used in 5G communication.


Asunto(s)
Calor , Agua , Siloxanos , Temperatura
4.
Artículo en Inglés | MEDLINE | ID: mdl-32674375

RESUMEN

Clarifying the impact mechanisms of landscape patterns on ecosystem services is highly important for effective ecosystem protection, policymaking, and landscape planning. However, previous literature lacks knowledge about the impact mechanisms of landscape patterns on ecosystem services from a spatial perspective. Thus, this study measured landscape patterns and the ecosystem services value (ESV) using a series of landscape pattern metrics and an improved benefit transfer method based on land-use data from 2015. It explores the impact mechanisms of the landscape pattern metrics on the ESV using the ordinary least-squares method and spatial regression models in the middle reaches of the Yangtze River Urban Agglomerations (MRYRUA), China. We found that forestland was the main landscape type in the MRYRUA, followed by cultivated land, and the fragmentation degree of cultivated land was significantly higher than that of forestland. The findings demonstrate that landscape pattern metrics had a significant impact on ecosystem services, but could vary greatly. Moreover, ecosystem services in the MRYRUA exhibited significant spatial spillover effects and cross-regional collaborative governance was an effective means of landscape planning. This paper acts as a scientific reference and effective guidance for landscape planning and regional ecosystem conservation in MRYRUA and other similarly fast-growing urban agglomerations.


Asunto(s)
Ecosistema , Ríos , China , Conservación de los Recursos Naturales , Bosques
5.
Chem Sci ; 9(5): 1311-1316, 2018 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-29675177

RESUMEN

Although chelation-assisted C-H olefination has been intensely investigated, Pd(ii)-catalyzed C-H olefination reactions are largely restricted to acrylates and styrenes. Here we report a quinoline-derived ligand that enables the Pd(ii)-catalyzed olefination of the C(sp2)-H bond with simple aliphatic alkenes using a weakly coordinating monodentate amide auxiliary. Oxygen is used as the terminal oxidant with catalytic copper as the co-oxidant. A variety of functional groups in the aliphatic alkenes are tolerated. Upon hydrogenation, the ortho-alkylated product can be accessed. The utility of this reaction is also demonstrated by the late-stage diversification of drug molecules.

6.
Org Lett ; 20(1): 284-287, 2018 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-29256621

RESUMEN

Here we report an aerobic Pd(0) catalyzed C2-H functionalization of indoles and pyrroles with tethered N-methoxylamide as the directing group. A Pd(0)-initiated mechanism overcomes the directing or poisoning effect from a wide range of heterocycles including pyridine, pyrimidine, and thiazole. The imidazo[1,5-a]indole products are transformed to bioactive analogs after one-step manipulations, demonstrating the potential utility of this reaction in drug discovery.

7.
Fa Yi Xue Za Zhi ; 30(6): 434-6, 2014 Dec.
Artículo en Chino | MEDLINE | ID: mdl-25816574

RESUMEN

OBJECTIVE: To study the correlation of daily living activities with location and severity of trau- matic brain injury (TBI) and to provide a theoretical basis for improving the accuracy of expert opinion. METHODS: Five hundred and one cases of patients with TBI were selected. Detailed records included following: pre-injury situation, location and severity of injury, treatment and education. Daily living activi- ties scale (Barthel index) was applied to test the subjects' daily living activities. The relevance among location and severity of TBI and Barthel index was statistically analyzed. RESULTS: In mild TBI group, there was no significant difference in Barthel index among each location (P>0.05). In moderate TBI group, there were significant differences in Barthel index between subarachnoid hemorrhage and cerebral lobe injury, also between parietal, occipital lobes injury and frontal lobe injury, parietal, occipital lobes injury and temporal lobe (P<0.05), respectively, whereas no significant difference in Barthel index between frontal lobe injury and temporal lobe injury (P>0.05). In severe TBI, there were significant differences in Barthel index between every two different locations (P<0.05). CONCLUSION: There is some correlation between the location of TBI and Barthel index, which provides an important reference value for analyzing and determining daily living activities after TBI.


Asunto(s)
Actividades Cotidianas , Lesiones Encefálicas/rehabilitación , Evaluación de Resultado en la Atención de Salud , Adulto , Femenino , Humanos , Masculino , Índices de Gravedad del Trauma
8.
Chin Med J (Engl) ; 126(10): 1953-6, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23673117

RESUMEN

BACKGROUND: The degree of pathological microvascular proliferation is an important element in evaluation of the astrocytoma grade. This study was aimed to quantitatively assess the microvascular permeability of brain astrocytoma with the volume transfer constant (K(trans)) and volume of extravascular extracellular space per unit volume of tissue (Ve) from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and to evaluate the effectiveness of the K(trans) and Ve in the grading of astrocytoma. METHODS: The highest values of the K(trans) and Ve of 67 patients with astrocytoma (27 with grade II, 12 with grade III, and 28 with grade IV) were obtained. The comparisons of the differences of the K(trans) and Ve between the different grades were conducted using the Mann-Whitney rank-sum tests. Spearman's rank correlation coefficients were determined between K(trans) values, Ve values and astrocytoma grades. Receiver operating characteristic (ROC) curve analyses were performed to determine the cut-off values for the K(trans) and Ve to distinguish between the different grades of astrocytoma. RESULTS: There were significant differences (P < 0.001) between the different grades in the K(trans) values and Ve values, except for grades III and IV. The K(trans) values and Ve values were both correlated with astrocytoma grades (both P < 0.001). The ROC curve analyses showed that the cut-off values for the K(trans) and Ve provided the best combination of sensitivity and specificity in distinguishing between grade II and grade III or IV astrocytomas. CONCLUSIONS: DCE-MRI can play an important role in assessing the microvascular permeability and the grading of brain astrocytoma.


Asunto(s)
Astrocitoma/patología , Astrocitoma/fisiopatología , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/fisiopatología , Permeabilidad Capilar/fisiología , Adolescente , Adulto , Anciano , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Adulto Joven
9.
J Clin Neurosci ; 20(8): 1110-3, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23673143

RESUMEN

This study was designed to quantitatively assess the microvascular permeability of oligodendroglioma using the volume transfer constant (K(trans)) and the volume of the extravascular extracellular space per unit volume of tissue (V(e)) with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). We aimed to evaluate the effectiveness of K(trans) and V(e) in distinguishing between low-grade and anaplastic oligodendroglioma. The maximal values of K(trans) and V(e) for 65 patients with oligodendroglioma (27 grade II, 38 grade III) were obtained. Differences in K(trans) and V(e) between the two groups were analysed using the Mann-Whitney rank-sum test. Receiver operating characteristic (ROC) curve analyses were performed to determine the cut-off values for the K(trans) and Ve that could differentiate between low-grade and anaplastic oligodendrogliomas. Values for K(trans) and Ve in low-grade oligodendrogliomas were significantly lower than those in anaplastic oligodendrogliomas (p < 0.001 and p < 0.001, respectively). ROC curve analysis showed that cut-off values of the K(trans) (0.037 min(-1)) and Ve (0.079) could be used to distinguish between low-grade and anaplastic oligodendrogliomas in a statistically significant manner. Our results suggest that DCE-MRI can distinguish the differences in microvascular permeability between low-grade and anaplastic oligodendrogliomas.


Asunto(s)
Neoplasias Encefálicas/irrigación sanguínea , Permeabilidad Capilar/fisiología , Imagen de Difusión por Resonancia Magnética/métodos , Gadolinio/farmacocinética , Oligodendroglioma/irrigación sanguínea , Adolescente , Adulto , Anciano , Imagen de Difusión por Resonancia Magnética/instrumentación , Femenino , Humanos , Aumento de la Imagen , Masculino , Persona de Mediana Edad , Oligodendroglioma/clasificación , Índice de Severidad de la Enfermedad , Método Simple Ciego , Adulto Joven
11.
Eur J Radiol ; 75(2): 134-8, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19443158

RESUMEN

BACKGROUND AND PURPOSE: Although diffusion characteristics of white matter (WM) and its aging effects have been well described in the literature, diffusion characteristics of grey matter (GM), especially the cortical GM, have not been fully evaluated. In the present study, we used the fluid-inversion prepared diffusion imaging (FLIPD) technique to determine if there are age-related water diffusivity changes in GM. MATERIALS AND METHODS: 120 healthy volunteers were recruited for our study. They were divided into three age groups: group one (20-39 years old), group two (40-59 years old) and group three (60 years or older). All patients were evaluated with MRI using FLIPD at 3.0T. Apparent diffusion coefficient (ADC) values of the frontal GM, cingulate cortex and thalami were determined bilaterally by region-of-interest analysis. RESULTS: Group three had significantly higher ADC values in both thalami and the left frontal GM compared to group two or group one. No ADC value difference was found among the three groups in the right frontal GM and bilateral cingulate cortex. There was a significant positive correlation between individual ADC values and age in both thalami and left frontal GM. For the cingulate cortex and the right frontal GM, ADC values did not correlate significantly with advancing age. CONCLUSION: Statistically significant age-related diffusion changes were observed in both thalami and the left frontal cortex. The data reported here may serve as a reference for future studies.


Asunto(s)
Envejecimiento/patología , Imagen de Difusión por Resonancia Magnética , Lóbulo Frontal/patología , Tálamo/patología , Adulto , Anciano , Femenino , Giro del Cíngulo/patología , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
12.
AJR Am J Roentgenol ; 191(2): 582-8, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18647936

RESUMEN

OBJECTIVE: The purpose of our study was to describe the characteristic MRI appearance of cerebral infection with Schistosoma japonicum. CONCLUSION: Cerebral infection with S. japonicum can cause a characteristic MRI pattern of a large mass comprising multiple intensely enhancing nodules, sometimes with areas of linear enhancement. The typical appearance may be useful for diagnosis in endemic regions and may potentially be useful in cases imported into countries in which the disease is not endemic.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Neuroesquistosomiasis/diagnóstico , Adolescente , Adulto , Anciano , Animales , Niño , Medios de Contraste , Diagnóstico Diferencial , Femenino , Gadolinio DTPA , Humanos , Masculino , Persona de Mediana Edad , Neuroesquistosomiasis/parasitología , Schistosoma japonicum
13.
J Comput Assist Tomogr ; 30(6): 975-9, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17082705

RESUMEN

OBJECTIVE: To analyze extracerebral cavernous malformation located in the cavernous sinus and correlate their magnetic resonance imaging (MRI) features to pathological findings. MATERIALS AND METHODS: Nineteen patients (5 men and 14 women; mean age, 50.6 years; range, 32-71 years) with surgically verified cavernous malformations in the cavernous sinus were reviewed. MRI including T1-weighted, T2-weighted, and postcontrasted T1-weighted imaging was carried out in all instances with a 1.5-T superconductive system (Signa; General Electric Medical Systems, Milwaukee, WI). RESULTS: All these lesions measured from 2.5 cm to 6 cm (average, 4.3 cm) with 13 lesions located to the right side and 6 to the left side. Magnetic resonance images showed that 18 cases were hypointense to white matter on T1-weighted images with only one case showed mixed hypointensity and hyperintensity. On T2-weighted images, 17 cases showed marked homogeneous hyperintensity, 1 case showed marked hyperintensity with some signal void structures and 1 with mixed intensity. Marked homogeneous enhancement after contrast material administration was found in 7 cases, and the remaining 12 showed marked heterogeneous enhancement. Pathologically, these lesions can be classified as type A, type B, and type C. Type A was sponge-like with intact pseudocapsule; type B was mulberry-like with the pseudocapsule incomplete or absent; and type C was composed of both mulberry-like composition and sponge-like composition. Lesions with homogeneous contrast enhancement on MRI correlated with type A pathological findings, whereas those with heterogeneous enhancement correlated with type B and type C pathological findings. Asymmetrical dumbbell-shaped masses of 13 cases involving the sellar and round masses of 6 cases with 2 protruding into the sellar were found. All of the cavernous malformations displaced the adjacent temporal lobe without adjacent brain edema. The internal carotid arteries were displaced or encased in all cases. CONCLUSIONS: If a well-demarcated, homogeneous high signal intensity lesion on T2-weighted images with a dumbbell configuration involving both parasellar and sellar regions with marked heterogeneous or homogeneous enhancement is found, the diagnosis of cavernous sinus cavernous malformation should be entertained.


Asunto(s)
Seno Cavernoso/anomalías , Seno Cavernoso/patología , Hemangioma/patología , Imagen por Resonancia Magnética , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
14.
Chin Med J (Engl) ; 119(6): 467-73, 2006 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-16584644

RESUMEN

BACKGROUND: Contrast-enhanced fluid-attenuated inversion-recovery (FLAIR) magnetic resonance imaging (MRI) has been reported to have higher sensitivity for detecting leptomeningeal disease compared with contrast-enhanced T1-weighted MRI (CE T1WI). However, currently there are no studies showing the potential value of clinical applications of contrast-enhanced FLAIR (CE FLAIR) sequence in diagnosing intracranial tumors in a larger group of patients. The purpose of this study was to evaluate the diagnostic value of CE FLAIR in comparison with CE T1WI for intracranial tumors and to provide more information for clinical diagnosis and therapy. METHODS: One hundred and four consecutive cases of intracranial tumors referred for CE brain MRI were analyzed with regard to FLAIR and T1WI pre- and post-administration of Gd-DTPA. The CE FLAIR and CE T1WI were evaluated independently by two radiologists for the number of examinations with one or more enhanced lesions, the number and location of enhanced lesions per examination, signal-to-noise ratio (SNR) and contrast-enhancement ratio (CER) of lesions, as well as the size and extent of the enhanced lesions. RESULTS: In 98 of 104 cases, enhanced lesions were seen both on the FLAIR and T1W images. More lesions were seen on CE T1WI (n = 120) than those on CE FLAIR sequence (n = 117), but no differences of statistical significance were found between the two sequences (P > 0.05). Four lesions were revealed only on the CE FLAIR images whereas 7 lesions were only found on CE T1WI. Enhanced lesions located in the cerebral hemisphere or the forth ventricle were revealed much more on CE T1WI than on CE FLAIR images. However, CE FLAIR images may be useful in showing superficial abnormalities and those located in the sulcus or lateral ventricle. The CER and contrast-to-noise ratio (CNR) on CE T1WI was significantly higher (t = 7.10, P = 0.00; t = 9.67, P = 0.00, respectively), but grey matter/white matter contrast was lower (t = 2.46, P = 0.02) than those on CE FLAIR images. The SNR did not show any statistically significant difference between the two sequences (t = 1.1, P = 0.27). The size and extent of lesions on the CE FLAIR images were significantly larger than those on CE T1WI (t = 4.13, P = 0.00). CONCLUSIONS: CE FLAIR and CE T1WI may complement each other in showing intracranial tumors and the CE FLAIR sequence should be selected as a routine MRI sequence.


Asunto(s)
Neoplasias Encefálicas/diagnóstico , Medios de Contraste , Aumento de la Imagen , Imagen por Resonancia Magnética/métodos , Adolescente , Adulto , Anciano , Neoplasias Encefálicas/patología , Niño , Preescolar , Femenino , Gadolinio DTPA , Humanos , Masculino , Persona de Mediana Edad
15.
Zhonghua Yi Xue Za Zhi ; 85(39): 2775-9, 2005 Oct 19.
Artículo en Chino | MEDLINE | ID: mdl-16324320

RESUMEN

OBJECTIVE: To study the efficacy of diffusion tensor tracking (DTT) in study of the normal and abnormal cerebral white matter fiber. METHODS: Ten normal adult volunteers, 5 males and 5 females, aged 40.9 (24-65), and 28 patients with cranial tumors, 9 males and 19 females, aged 43.0 (11-77), underwent MR diffusion tensor. The data thus obtained were transferred to a personal computer and processed with dTV. RESULTS: The main cerebral white matter fiber pathways were successfully observed. Association fibers, including arcuate fibers, cingulum, superior and inferior longitudinal fasciculus, and inferior fronto-occipital fasciculus, commissural fibers (corpus callosum), and projection fibers (corticospinal tract) were revealed. The arcuate fibers, cingulum, superior and inferior longitudinal fasciculus, corticospinal tract, external capsule, optic radiation, and corpus callosum were all involved by intracranial tumors. The abnormality of cerebral white matter could be classified into 4 groups: disruption + infiltration (7 cases), disruption + displacement (10 cases), infiltration + displacement (3 cases), and displacement (8 cases). CONCLUSION: DTT is useful for showing the main normal and abnormal cerebral white mater fiber tracts, thus opening a new field foe research of cerebral white matter fiber in vitro.


Asunto(s)
Mapeo Encefálico/métodos , Neoplasias Encefálicas/patología , Encéfalo/patología , Imagen de Difusión por Resonancia Magnética , Fibras Nerviosas Mielínicas/patología , Adolescente , Adulto , Anciano , Niño , Cuerpo Calloso/patología , Imagen de Difusión por Resonancia Magnética/métodos , Femenino , Humanos , Aumento de la Imagen , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Tractos Piramidales/patología
16.
Zhonghua Yi Xue Za Zhi ; 85(35): 2513-7, 2005 Sep 14.
Artículo en Chino | MEDLINE | ID: mdl-16321282

RESUMEN

OBJECTIVE: To analyze the findings of MR diffusion weighted imaging (DWI) and diffusion tensor Imaging (DTI) in patients with multiple sclerosis (MS), and to explore their role in reflecting the pathological changes of MR lesions. METHODS: DWI and DTI were performed on 41 MS cases and 25 sub-acute brain infarct cases which used as control group. The appearances of ADC maps, EADC maps and FA maps in patients of both groups were analyzed. Quantitative analysis of the values of ADC, EADC and FA in the center and periphery of the lesions of acute MS, chronic MS and sub-acute brain infarct was carried out separately. RESULT: In DWI, the small chronic lesions were iso-intensity, and the large acute MS lesions and the sub-acute-infarct lesions had a high signal intensity to various degrees. In the EADC map, only in 13 cases with acute MS around the peripheral zone of the lesions there was a high signal intensity, and all other cases, including the cases with chronic MS and brain infarct had no high signal lesions. The ADC values of chronic and infarct lesions were similar (P > 0.05), both of them had the highest ADC value which were higher than the signal intensity in the center (both P < 0.05) and the periphery (both P < 0.05) of the MS lesions. The FA values in the infarct lesions were the lowest, much more lower than that in the chronic MS lesions (P < 0.05). The FA value in the center of acute MS lesions was lower than that in the peripheral zone (P < 0.05), and higher than the FA value both in the chronic MS and infarct lesions (P < 0.05). The lowest ADC value outside the peripheral zone of acute MS lesions and the highest EADC value were found. CONCLUSION: The significance of DWI high signal in the diagnosis and differential diagnosis of MS is not reliable, so the patient's history and the findings found in the routine MRI must be conjugated when an imaging diagnosis is made. The EADC map is more accurate than ADC map for showing the diffusion restriction of water molecular in the MS lesions. The degree of increase of the ADC value and the degree of decease of the FA value are proportional to the degree of severity of the pathological changes of the MS lesions.


Asunto(s)
Infarto Encefálico/patología , Encéfalo/patología , Imagen de Difusión por Resonancia Magnética/métodos , Esclerosis Múltiple/patología , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/diagnóstico , Adulto Joven
17.
Zhonghua Yi Xue Za Zhi ; 84(14): 1181-5, 2004 Jul 17.
Artículo en Chino | MEDLINE | ID: mdl-15387980

RESUMEN

OBJECTIVE: To explore the value of magnetization transfer imaging (MTI) in judging microscopic lesions in normal-appearing white matter of multiple sclerosis (MS). METHODS: Forty-one patients with brain MS, 17 males and 24 females, aged 13 approximately 65, and 21 healthy people, 8 males and 13 females, aged 18 approximately 57, used as controls underwent magnetic resonance imaging (MRI) using 3D-spoiled grass (3D-SPGR) series, to scan the whole brain with saturated pulses on and off respectively. The signal values were measured directly in the pictures of these 2 series. The formula MTR = (M(0)-MS)/M(0) x 100% was used, where M0 represents the signal value of region of interest with the saturated pulses off, and Ms represents signal value of region of interest with the saturated pulses on, to calculate the MTR value. With reference to T(2)WI imaging, the MTR values of 17 regions of interest (ROI) in the normal-appearing brain white matter, including the white matter of pons, bilateral cerebellar peduncles, knees of internal capsules, splenium and genu of corpus callosum, and the white matter by the anterior horn and posterior horn of lateral ventricle, body of lateral ventricle, and deep in the frontal and parietal lobes, were measured. The average MTR value of the 17 ROI was used to represent the MTR value of the whole normal-appearing brain and used to make comparison with that of the healthy samples statistically. RESULTS: Compared with those of the healthy samples, the average MTR values of each ROI of the MS patients were lower at different degrees. The difference in the MTR values of the white matter of splenium of corpus callosum, and by lateral ventricle and deep in parietal lobe were especially bigger. The MTR value of the whole brain white matter in the healthy persons ranged from 22.76% to 25.42%, with an average value of 23.97%, both significantly higher than those of the MS patients (19.45% to 24.15%, and 22.44% respectively, both P < 0.05). CONCLUSION: MTI can be used to detect the microchange of normal appearing white matter in MS. MTR is a sensitive indicator to reflect the damage of structure of tissues.


Asunto(s)
Encéfalo/patología , Imagen por Resonancia Magnética/métodos , Esclerosis Múltiple/diagnóstico , Adolescente , Adulto , Anciano , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/patología , Esclerosis Múltiple/fisiopatología
18.
Zhonghua Yi Xue Za Zhi ; 83(18): 1586-91, 2003 Sep 25.
Artículo en Chino | MEDLINE | ID: mdl-14642115

RESUMEN

OBJECTIVE: To evaluate the prognostic value of hippocampal MRI scan, MRI volumetry and 1H MRS in patients with temporal lobe epilepsy (TLE). METHODS: 50 intractable TLE patients operated in Huashan hospital were studied. Before surgery, traditional MRI scans were used to exclude tumor and vascular malformation of the brain. All patients were examined by tilted coronal images which were perpendicular to the long axis of the hippocampus, using T1-weighted, T2-weighted and FLAIR sequence. MRI volumetric measurement of both hippocampal formation were performed. 38 patients also took 1H MRS scan. Unilateral anterior temporal lobectomy was performed in all patients and pathology showed different degrees of hippocampal sclerosis. The prognosis was categorized into three grades with grade I being assigned to the group of good outcome, and grade II and III being assigned to the bad outcome group. Correlative analysis between the results of several examinations and the prognosis were performed respectively. RESULTS: MRI-positive cases with hippocampal scans were about 84% of the 50 cases. Hippocampal atrophy, increase of signal intensity or the loss of internal morphological structure were detected. 98% of the MRI-positive patients had good outcome, and 38% of the MRI-negative patients had good outcome. The prognosis between MRI-positive group and MRI-negative group had significant difference (chi(2) = 23.00, P = 0.000). Among the right-side operated cases, the average hippocampal volume on the operated side of the bad outcome group was larger than that of the good outcome group. While among the left-side operated cases, the hippocampal volume on the non-operated side of the bad outcome group was smaller than that of the good outcome group. Significant differences were found in statistics respectively. In both groups, prognosis was found to be statistically related to the DHF value (difference of bilateral hippocampal volume). The DHF value of the good outcome group was larger than that of the bad outcome group. 38 patients took 1H MRS examination. The average NAA/(Cr + Cho) ratio on the operated side of the patients in the bad outcome group was greater than that of the good outcome group. The average NAA/(Cr + Cho) ratio on the contralateral side of the patients in the bad outcome group was lower than that of the good outcome group. But no significant differences were found in statistics respectively. 90% cases of MRS unilateral abnormalities had good outcome, while 77% cases of MRS bilateral abnormalities had good outcome. But no statistically significant difference was found among different groups (chi(2) = 0.493, P = 0.781). CONCLUSION: Hippocampal MRI scan, MRI volumetry and 1H MRS may be used as prognostic tools in TLE patients before surgery. The combination of several noninvasive methods before surgery can help choose suitable patients for surgery, and, as a result, improve surgical outcome.


Asunto(s)
Epilepsia del Lóbulo Temporal/diagnóstico , Adolescente , Adulto , Niño , Epilepsia del Lóbulo Temporal/patología , Epilepsia del Lóbulo Temporal/cirugía , Femenino , Hipocampo/patología , Humanos , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos
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