磁共振氢质波谱成像评估高强度聚焦超声治疗原发性肝癌疗效的可行性及其价值

目的 通过比较原发性肝癌高强度聚焦超声(HIFU)治疗前后胆碱峰、脂质峰下积分面积及胆碱/脂质峰下积分面积比值的变化,探讨磁共振氢质波谱成像(1H-MRS)在HIFU治疗原发性肝癌疗效评估中的价值及可行性.方法 24例原发性肝癌患者于HIFU治疗前及治疗后2周内行常规磁共振平扫及动态增强扫描.以呼吸触发的横轴位T2WI...     

急性期脑梗死磁共振波谱成像初步研究

目的分析评估急性脑梗死代谢物氢质子磁共振波谱成像（1HMRS）的临床应用价值。方法 对32例急性期脑梗死患者进行常规核磁共振（MRI）及1HMRS扫描,梗死区N-乙酰天门冬氨酸（NAA）,肌酸（Cr）,胆碱化合物（Cho）与对侧相应正常脑区代谢产物比值（rNAA、rCr、rCho）及同侧乳酸/胆碱值（Lac/Cho）,比较不同部位各代谢产物相对浓度。结果 rCr（F=6.102,P=0.085）各区域间无显著差异;rCho（F=2.229,P=0.094）各区域间无显著差异;rNAA中央部与外侧缘间有显著差异（F=2711.140,P〈0.05）;Lac/Cho区域各组间均有显著差异（F=29127.575,P=0.000）。结论 1HMRS检查对急性期脑梗死的诊断价值明显高于常规MRI,可同时检测脑梗死的进展情况。作为一种无创伤活体显示组织代谢的影像学方法1HMRS具有广阔的应用前景。     

磁共振波谱成像观察多发性硬化与视神经脊髓炎患者丘脑代谢产物

目的利用1H-MRS探讨多发性硬化（MS）及视神经脊髓炎（NMO）患者丘脑代谢产物的变化。方法对32例MS患者（MS组）、28例NMO患者（NMO组）和35名健康志愿者（正常对照组）行丘脑1H-MRS扫描,计算并比较各组丘脑代谢产物比值[N-乙酰天门冬氨酸（NAA/Cr）、胆碱/肌酸（Cho/Cr）、肌醇/肌酸（mI/Cr）]。结果三组间NAA/Cr差异有统计学意义（P〈0.05）。与正常对照组比较,MS组丘脑NAA/Cr明显减低（t=-3.45,P〈0.05）,而Cho/Cr及mI/Cr差异无统计学意义（t=0.086、0.661,P均〉0.05）。与正常对照组比较,NMO组丘脑NAA/Cr、Cho/Cr及mI/Cr差异均无统计学意义（t=-0.792、1.408、1.735,P均〉0.05）。结论 1H-MRS显示MS患者丘脑NAA/Cr减低,提示此区域存在轴索损伤,而NMO患者丘脑受损不明显,反映出MS与NMO存在不同的病理变化,有助于二者的鉴别诊断。     

COVID-19-related cognitive dysfunction may be associated with transient disruption in the DLPFC glutamatergic pathway

Cognitive impairment has recently attracted researchers as one of the possible neuropsychiatric manifestations of COVID-19, although how the infection perpetuates impairment of cognitive functions is still obscure. We presented a 29-year-old male patient with COVID-19 who developed new-onset transient attention deficit and memory problems following a SARS-CoV-2 infection. Structural neuroimaging was normal. MR-spectroscopy (MRS) of the bilateral DLPFC revealed significant for decreased levels of N-acetylaspartate (NAA), glutamate, and glutamate/glutamine ratio. After a follow-up without any medical treatment but with suggestions of memory exercises for three months a control MRS screening of DLPFC showed improved levels of NAA, glutamate, and glutamate/glutamine ratio. This report may suggest that cognitive deficits in SARS-CoV-2 infection can result from glutamatergic dysfunction with decreased NAA and glutamate levels in bilateral DLPFC.     

Functional near-infrared spectroscopy during the verbal fluency task of English-Speaking adults with mood disorders: A preliminary study

Functional near-infrared spectroscopy (fNIRS) provides a direct and objective assessment of cerebral cortex function. It may be used to determine neurophysiological differences between psychiatric disorders with overlapping symptoms, such as major depressive disorder (MDD) and bipolar disorder (BD). Therefore, this preliminary study aimed to compare fNIRS signals during the verbal fluency task (VFT) of English-speaking healthy controls (HC), patients with MDD and patients with BD. Fifteen HCs, 15 patients with MDD and 15 patients with BD were recruited. Groups were matched for age, gender, ethnicity and education. Relative oxy-haemoglobin and deoxy-haemoglobin changes in the frontotemporal cortex was monitored with a 52-channel fNIRS system. Integral values of the frontal and temporal regions were derived as a measure cortical haemodynamic response magnitude. Both patient groups had lower frontal and temporal region integral values than HCs, and patients with MDD had lower frontal region integral value than patients with BD. Moreover, patients could be differentiated from HCs using the frontal and temporal integral values, and patient groups could be differentiated using the frontal region integral values. VFT performance, clinical history and symptom severity were not associated with integral values. These results suggest that prefrontal cortex haemodynamic dysfunction occurs in mood disorders, and it is more extensive in MDD than BD. The fNIRS-VFT paradigm may be a potential tool for differentiating MDD from BD in clinical settings, and these findings need to be verified in a larger sample of English-speaking patients with mood disorders.     

Comparison of cerebral activation between motor execution and motor imagery of self-feeding activity

Motor imagery is defined as an act wherein an individual contemplates a mental action of motor execution without apparent action. Mental practice executed by repetitive motor imagery can improve motor performance without simultaneous sensory input or overt output. We aimed to investigate cerebral hemodynamics during motor imagery and motor execution of a self-feeding activity using chopsticks. This study included 21 healthy right-handed volunteers. The self-feeding activity task comprised either motor imagery or motor execution of eating sliced cucumber pickles with chopsticks to examine eight regions of interest: pre-supplementary motor area, supplementary motor area, bilateral prefrontal cortex, premotor area, and sensorimotor cortex. The mean oxyhemoglobin levels were detected using near-infrared spectroscopy to reflect cerebral activation. The mean oxyhemoglobin levels during motor execution were significantly higher in the left sensorimotor cortex than in the supplementary motor area and the left premotor area. Moreover, significantly higher oxyhemoglobin levels were detected in the supplementary motor area and the left premotor area during motor imagery, compared to motor execution. Supplementary motor area and premotor area had important roles in the motor imagery of self-feeding activity. Moreover, the activation levels of the supplementary motor area and the premotor area during motor execution and motor imagery are likely affected by intentional cognitive processes. Levels of cerebral activation differed in some areas during motor execution and motor imagery of a self-feeding activity. This study was approved by the Ethical Review Committee of Nagasaki University(approval No. 18110801) on December 10, 2018.     

tDCS-induced modulation of GABA concentration and dopamine release in the human brain: A combination study of magnetic resonance spectroscopy and positron emission tomography

BackgroundTranscranial direct current stimulation (tDCS) to the dorsolateral prefrontal cortex (DLPFC) hypothetically modulates cognitive functions by facilitating or inhibiting neuronal activities chiefly in the cerebral cortex. The effect of tDCS in the deeper brain region, the basal ganglia-cortical circuit, remains unknown.ObjectiveTo investigate the interaction between γ-aminobutyric acid (GABA) concentrations and dopamine release following tDCS.MethodThis study used a randomized, placebo-controlled, double-blind, crossover design. Seventeen healthy male subjects underwent active and sham tDCS (13 min twice at an interval of 20 min) with the anode placed at the left DLPFC and the cathode at the right DLPFC, followed by examinations with [¹¹C]-raclopride positron emission topography (PET) and GABA-magnetic resonance spectroscopy (MRS). MRS voxels were set in the left DLPFC and bilateral striata. Paired t-tests and regression analyses were performed for PET and MRS parameters.ResultsMRS data analyses showed elevations in GABA in the left striatum along with moderate reductions in the right striatum and the left DLPFC after active tDCS. PET data analyses showed that reductions in [¹¹C]-raclopride binding potentials (increase in dopamine release) in the right striatum were inversely correlated with those in the left striatum after active tDCS. GABA reductions in the left DLPFC positively correlated with elevations in GABA in the left striatum and with increases in right striatal dopamine release and negatively correlated with increases in left striatal dopamine release.ConclusionThe present results suggest that tDCS to the DLPFC modulates dopamine-GABA functions in the basal ganglia-cortical circuit.     

磁共振H1-MRS和DTI联合应用诊断胶质瘤的价值

目的:探讨联合应用磁共振波谱成像(H1-MRS)和弥散张量成像(DTI)对于判别胶质瘤良、恶性和侵袭性的价值,为临床全面评估胶质瘤生物学特性并制定合理治疗方案提供影像学支持.方法:13例低级别胶质瘤和12例高级别胶质瘤患者均行常规MRI、MRS和DTI检查,测量相关参数,分别对2组患者组内及组间参数进行比较,并通过纤维...     

应用近红外光谱技术对胶质瘤大鼠射频热疗的实时在位监测研究

目的:观察近红外光谱(near-infrared spectroscopy,NIRS)光学参数在胶质瘤射频热疗术中的变化规律,探讨利用NIRS对胶质瘤射频热疗进行实时监测的可行性.方法:将C6胶质瘤细胞注入大鼠脑右侧尾状核建立胶质瘤大鼠模型;在不同时间、温度下对荷瘤大鼠进行靶向毁损,观察并记录肿瘤组织射频加热时靶点的N...     

液相色谱-质谱联用法测定人血浆中富马酸单甲酯药物浓度及应用

目的： 建立液相色谱-质谱联用（HPLC-MS/MS）法测定人血浆中富马酸单甲酯的方法,并应用于检测中国健康受试者血浆中富马酸单甲酯的浓度。方法： 血浆样品用醋酸铵稀释后经过96孔固相萃取板前处理,以含0.5%甲酸的水溶液和甲醇作为流动相,采用梯度洗脱方式在ACE Excel 3 C₁₈-AR（2.1 mm×50 mm）色谱柱上进行分离,每个样品分析时间为4 min。在电喷雾负电离模式下,多反应监测检测离子对m/z 129.0→m/z 85.0（富马酸单甲酯）和m/z 134.0→m/z 90.0（内标,富马酸单甲酯-d₅）。结果： 富马酸单甲酯线性范围为4~1 200 ng·mL^-1（r²>0.99）,定量下限为4 ng·mL^-1,日内和日间精密度RSD ≤ 9.7%,准确度相对偏差均在±4.2%以内,平均回收率RSD ≤ 6.6%,基质效应在98.3%~100.9%之间。稳定性实验中,各种储存条件不影响对药品浓度的准确测定。结论： 本方法运行时间短,灵敏度高,重复性好,适用于富马酸单甲酯血浆浓度定量检测。