脑脓肿磁共振弥散加权成像动态变化

目的:研究脑脓肿弥散加权成像(DWI)的动态变化过程。材料和方法:对14例脑脓肿患者进行常规MRI检查和DWI检查并随访,观察脑脓肿在脑炎期、包膜期和吸收期常规MRI和DWI的变化。结果:脑炎期表现为稍长T2信号,DWI呈等信号;包膜期出现T2WI低信号环,环形增强,脓腔DWI呈高信号;吸收期T2WI脓腔高信号逐渐缩小,最后成为一低信号的结节,呈浅淡增强,DWI信号逐渐减低。结论:脑脓肿的DWI随着脓肿各期的演变而变化,DWI能为脓肿的分期提供有价值的信息。

磁共振弥散加权成像在急性脑梗死诊断中的应用价值研究

目的 研究磁共振弥散加权成像(DWI)诊断急性脑梗死的价值。方法 对86例临床诊断为脑梗死的病例进行DWI和常规MRI扫描,分析在脑梗死不同时期DWI的表现。结果 在起病的超急性期及急性期(>6小时,<48小时)DWI显示率为100％,病灶大小为(24.8±21.6)mm,T2/FLAIR上病灶大小为(7.9±6.8)mm,两者比较的t=12.7,P<0.05,在亚急性期(2～14天)DWI与T2W加Flair比较,DWI不如T2W加Flair,对于慢性期脑梗死(超过14天),DWI不易辨认。结论DWI对急性期脑梗死的诊断准确率高,明显优于常规MRI。

磁共振成像检查患者焦虑情绪的因素分析和护理干预探讨

目的探究分析磁共振成像检查患者焦虑情绪的因素和护理干预效果.方法：选择 2016 年 1 月至 2018 年 1 月来我院进行磁共振成像检查的患者 118 例,采取数字随机分配法将其分为实验组和对照组,每组 59 例,分析两组患者产生焦虑情绪的原因,并且采取相应的护理干预措施,实验组接受心理护理,对照组接受常规护理,对比两组护理结果.结果：护理前,两组患者焦虑评分无明显差异,t=0.05,P=0.96,差异不具备统计学意义.护理后,实验组患者焦虑评分明显低于对照组,t=16.11,P=0.00,差异具有统计学意义.结论：在磁共振成像检查当中,分析患者产生焦虑情绪的原因,并且积极采取科学合理的护理干预措施,能够有效减轻患者的焦虑情绪,保证磁共振成像质量,临床意义重大.

定量磁共振成像在关节软骨中的应用研究进展

在临床上,关节软骨损伤是一种常见病,其发生发展可由外伤、骨性关节炎(osteoarthritis, OA)以及剥脱性骨软骨炎等原因造成,而且这种损坏发生后很难修复。关节软骨损伤主要表现为关节疼痛及功能障碍,关节软骨的损伤以及退变都不同程度地发生在老年人及长期剧烈运动的人群中。关节镜检查被认为是诊断关节软骨病变的金标准。但由于其有创检查的性质,对检查者的技术水平要求很高,且无法深入了解软骨的内部情况。定量磁共振成像(quantitative magnetic resonance imaging, qMRI)既可显示软骨形态学变化,又可以定量评估软骨的生化成分,由于该技术具有无创、良好的软组织分辨力、多参数、多平面成像的优势,它能以非侵入性的定量测量来敏感地监测软骨的微细变化,提供可靠和可重复的成像生物标志物。

Correlations of transcranial sonography of substantia nigra characteristics with MRI iron deposition on substantia nigra in patients with Parkinson disease

Objective To explore the correlations of transcranial sonography of substantia nigra(SN-TCS)characteristics with MRI iron deposition on substantia nigra in patients with Parkinson disease(PD).Methods Data of SN-TCS and craniocerebral MRI in 120 PD patients were retrospectively analyzed.The patients were divided into iron deposition positive group(positive group,n=46)and iron deposition negative group(negative group,n=74)according to quantitative susceptibility mapping(QSM)value.Then parameters of SN-TCS and MRI were compared between groups(both P<0.05),and correlation analysis were also performed.Results The proportion of high echo positive,strong echo area and QSM value of substantia nigra,as well as of hyper-substantia nigra area/midbrain area(S/M)in positive group were all higher than those in negative group(all P<0.001).No significant difference of midbrain area was found between groups(P>0.05).Strong echo area of substantia nigra and S/M based on SN-TCS were both low-medium positively correlated with substantia nigra QSM value showed on MRI(r=0.497,0.529,both P<0.001).Conclusion SN-TCS characteristics of PD patients were correlated with MRI iron deposition on substantia nigra,among which strong echo area and S/M were valuable for evaluating iron deposition on substantia nigra.

Preliminary clinical application of total free-breathing cardiac MR examination

Objective To observe the clinical application value of total free-breathing cardiac MR(CMR)examination preliminarily.Methods Two patients who underwent CMR scanning under free-breathing state,including cine,motion correction T1 and T2 mapping,blood flow imaging,and late gadolinium enhancement scanning were retrospectively enrolled,and the qualities of the above images were evaluated and compared with that of conventional CMR images under breath-holding state.Results No significant difference of imaging quality was found between total free-breathing and conventional breath-holding CMR.The differences of left ventricular ejection fraction,cardiac output,left ventricular end-diastolic volume index and left ventricular mass measured based on CMR images under different breath conditions were limited.Conclusion Total free-breathing CMR was feasible in clinical practice,which could provide"one-stop"evaluation of cardiac structure,function and myocardial histological characteristics,hence having promising clinical prospects.

Differentiating consistency of meningioma based on grey-level histogram analysis of T2WI

Objective To observe the value of grey-level histogram analysis based on T2WI for differentiating consistency of meningioma.Methods Data of 109 patients with meningioma were retrospectively analyzed.The patients were divided into hard group(n=71)and soft group(n=38)according to the consistency of tumors.Tumor ROI was outlined on axial T2WI showing the largest tumor section,gray levels were extracted and histogram analysis was performed.The value of each histogram parameter were compared between groups.Then receiver operating characteristic curve was drawn,and the area under the curve(AUC)was calculated to evaluate the efficiency for differentiating soft and hard meningioma.Results P 1,P 10,P 50,P 90,P 99 and the mean grey levels on T2WI in soft group were all higher than those in hard group(all P<0.05),while the variance,the kurtosis and the skewness were not significantly different between groups(all P>0.05).The differentiating efficiency of P 1,P 10,P 50,P 90,P 99 and the mean grey levels on T2WI were all fine,with AUC of 0.774 to 0.833,and no significant difference was found(all P>0.05).Conclusion Parameters of grey-level histogram analysis such as P 1,P 10,P 50,P 90,P 99 and the mean values based on T2WI were all valuable for differentiating soft and hard meningioma.

Intravoxel incoherent motion and dynamic contrast-enhanced MRI for assessing abnormalities of brucellosis spondylitis without conventional MRI changes

Objective To observe the value of intravoxel incoherent motion(IVIM)and dynamic contrast-enhanced MRI(DCE-MRI)for assessing abnormalities of brucellosis spondylitis(BS)without conventional MRI changes.Methods Data of 36 brucellosis patients with definite spinal lesions displayed on conventional MRI(BS 1 group),14 cases without brucellosis infection nor abnormal spinal signals on MRI(control group)and 36 brucellosis patients without definite spinal lesions on conventional MRI(BS 2 group)were retrospectively analyzed.The values of IVIM parameters,including perfusion fraction(f),pure water diffusion coefficient(D)and pseudo-diffusion coefficient(D*),also of DCE-MRI parameters,including time-intensity curve(TIC)type,volume transport constant(K trans),the rate constant(K ep)and volume fraction of extravascular extracellular space per unit tissue volume(V e)were compared among groups.Univariate and multivariate logistic regression were used to screen independent factors for discriminating BS 1 and BS 2.Receiver operating characteristic curves were drawn,and the areas under the curve(AUC)were calculated to evaluate the efficiency of the above parameters for discriminating BS 1 and BS 2.Results Among IVIM parameters,compared with control group,D*values decreased but D values increased in BS 1 group,while D*values increased in BS 2 group(all adjusted P<0.05).Compared with BS 2 group,BS 1 group had higher values of f and D and lower D*(all adjusted P<0.05).In BS 1 group,the TIC types were predominantly typeⅠ(23/36,63.89%),which were wholly or predominantly typeⅢin BS 2 group and control group,and of the former was significantly different with latter 2(both adjusted P<0.05).Compared with control group,K trans increased progressively in both BS 1 and BS 2 groups(both adjusted P<0.05).BS 1 group had lower K ep and higher V e than BS 2 and control groups(all adjusted P<0.05).Among univariate logistic regression models,the model including only f had lower capability for discriminating BS 1 and BS 2(AUC=0.759)than those including D,K trans and V e(AUC=0.951,0.833,0.894,all P<0.05).No significant different was found among multivariate logistic regression model including f and D,model including K trans and V e nor model including all above parameters(all P>0.05).Conclusion Both IVIM and DCE-MRI could be used to evaluate BS abnormality without conventional MRI changes.

Research progresses of artificial intelligence in MRI of lumbar degenerative diseases

The incidence of lumbar degenerative diseases is increasing year by year,and MRI is often used in clinical diagnosis.In recent years,artificial intelligence(AI)has rapidly developed in medical field and can be used for image segmentation and auxiliary diagnosis of lumbar degenerative diseases.The research progresses of AI in MRI of lumbar degenerative diseases were reviewed in this article.

Isotropic volumetric MRI for displaying cranial perineural spread of cranial nerve in nasopharyngeal carcinoma

Objective To observe the value of isotropic volumetric MRI for displaying perineural spread(PNS)of cranial nerve(CN)in nasopharyngeal carcinoma.Methods Eighty-seven patients with pathologically proven nasopharyngeal carcinoma were prospectively enrolled.MR scanning,including three-dimensional liver acquisition with volume acceleration-flexible(3D LAVA_Flex)image,T2WI with fat suppression(T2WI-FS),T1WI,contrast enhancement(CE)T1WI-FS of nasopharynx and neck region were performed.The displaying rates of CN PNS were evaluated and compared between 3D LAVA_Flex and T2WI-FS,T1WI,CE-T1WI-FS at patient level,CN group level and neural level,respectively.Results The displaying rate of CN PNS in all 87 nasopharyngeal carcinoma patients by 3D LAVA_Flex sequence was 49.43%(43/87),higher than that of conventional MRI(30/87,34.48%,P=0.001).Among 59 patients with advanced nasopharyngeal carcinoma diagnosed with conventional sequences,the displaying rate of CN PNS was 71.19%(42/59)by 3D LAVA-Flex sequence,higher than that of conventional MRI(30/59,50.85%,P=0.001).At both patient level and posterior CN level,significant differences of the displaying rate of CN PNS were found between 3D LAVA-Flex sequence and T2WI-FS,T1WI,CE-T1WI-FS,while at CN level,the displaying rates of mandibular nerve PNS,CNⅨ—ⅪPNS in jugular foramen(P<0.05)and CNⅨ—ⅫPNS in carotid space of 3D LAVA_Flex sequence were all significantly higher than that of T2WI-FS,T1WI and CE-T1WI-FS(all P<0.05),of PNS of CNⅢ—Ⅴin cavernous sinus were higher than that of T2WI-FS(P<0.05),while of PNS of hypoglossal nerve were significantly higher than that of T2WI-FS and T1WI(both P<0.05).Conclusion 3D LAVA_Flex sequence could be used to effectively display CN PNS of nasopharyngeal carcinoma.

Research progresses of resting-state functional MRI in mild cognitive impairment and Alzheimer's disease

Alzheimer's disease(AD)is a prevalent neurodegenerative disease characterized by cognitive decline in the early stage.Mild cognitive impairment(MCI)is considered as an intermediate stage between normal aging and AD.In recent years,studies related to resting-state functional MRI(rs-fMRI)indicated that the occurrence and development process of MCI and AD might be closely linked to spontaneous brain activity and alterations in functional connectivity among brain regions,and rs-fMRI could provide important reference for specific diagnosis and early treatment of MCI and AD.The research progresses of rs-fMRI for MCI and AD were reviewed in this article.

Long TR three-dimensional inversion recovery sequence with real reconstruction(3D real IR)for quantifying inner ear endolymphatic hydrops

Objective To observe the value of long TR three-dimensional inversion recovery sequence with real reconstruction(3D real IR)for quantifying inner ear endolymphatic hydrops(EH).Methods Totally 46 Ménière's disease(MD)patients and 21 healthy volunteers were prospectively enrolled.MR scanning for inner ear based on 3D real IR and 3D fluid attenuated inversion recovery(3D FLAIR)sequence 4—6 h after administration of contrast agents were performed.The imaging qualities were scored and compared between groups.The endolymphatic space area and the membranous labyrinth area of cochlea and vestibule,as well as endolymph/membranous labyrinth area percentage were calculated,the present or not of EH and the grade of EH were evaluated.EH inner ears of MD patients were enrolled in EH group,while inner ears of healthy volunteers were taken as controls(control group).The endolymphatic space area,membranous labyrinth area and endolymph/membranous labyrinth area percentage of cochlea and vestibule were compared between groups.The receiver operating characteristic(ROC)curve was drawn to calculate the diagnostic efficacy of the above indexes.Results Cochlear and/or vestibular EH were detected in 56 ears,including cochlear EH in 52 ears and vestibular EH in 45 ears among 46 MD patients(EH group),but not in 42 ears in control group.The subjective quality scores of 3D real IR images were higher than those of 3D-FLAIR(both P<0.05).Quantitative analysis based on 3D real IR images revealed that,compared with control group,significantly larger endolymph areas and endolymph/membranous labyrinth area percentages in both cochlea and vestibule were found in EH group(all P<0.001).The area under the curve(AUC)of cochlear or vestibular endolymph/membranous labyrinth area percentage for identifying inner ear EH was 0.999 and 0.985,respectively.Taken 13.64%and 24.13%as the critical value of cochlear or vestibular endolymph,the specificity was 100%and 92.86%,respectively,and the sensitivity was 96.43%and 96.43%,respectively.Conclusion MR long TR 3D real IR was helpful to quantifying inner ear EH.

外伤性脑梗塞的MRI成像与临床意义

目的 探讨 MRI在外伤性脑梗塞诊断中的价值及特征。方法 对 1 3例头颅外伤后 ,临床主要表现为不同程度偏瘫患者行 MRI检查。结果 1 3例头颅 MRI显示与相应血管供血区的梗塞灶 ,T1WI呈低信号 ,T2 WI呈高信号。结论 外伤性脑梗塞常见于儿童 ,好发于基底节 -内囊区 ,MRI检查对外伤性脑梗塞诊断准确 ,对临床治疗及估计预后有指导意义。

嗅神经母细胞瘤的MRI诊断价值

目的 :探讨 MRI在嗅神经母细胞瘤的诊断和分期中的价值。方法 :回顾性分析 4例经手术病理证实的嗅神经母细胞瘤的 MRI表现。扫描序列为 SE序列 ,且均行 Gd- DTPA增强扫描。结果 :按 Kadish分期标准 :本组 4例均为 C期 ,侵犯范围为鼻腔 4例 ,同侧筛窦及眼眶均受侵犯 2例 ,蝶窦、上颌窦和前颅窝均受侵 1例 ,眼眶及前颅窝均受侵者 1例。 MRI、T1 加权像呈低、中等信号 ,T2 加权像呈中等、高信号 ,病灶强化均匀或不均匀。结论 :MR扫描可界定嗅神经母细胞瘤的侵犯范围 ,冠状面扫描有助于显示眶内、颅内病变 ,必不可少。 MR扫描有利于肿瘤的 Kadish分期 ,从而指导临床制定合理的治疗方案。

腰椎间盘退行性病变致下腰痛的MRI和椎间盘造影的影像学比较

目的通过腰椎间盘造影和MRI影像学比较研究,评价腰椎间盘造影对慢性下腰痛患者的诊断价值。方法对32例患者66个椎间盘进行腰间盘造影及MRI检查。利用MRI与椎间盘造影的所见之异同将各期病变进行比较,了解椎间盘退行性变患者的髓核、纤维环以及引起诱发性疼痛的情况。结果(1)MRI检查表现为椎间盘突出、膨出、或形态正常、高度及信号降低(尤其在T2WI图像上)者,与椎间盘髓核造影检查时表现为髓核及纤维环退变为2、3期病变有明显的相关性。(2)椎间盘造影显示2～3期与0期表现,两组间引起诱发性疼痛差异存在显著性意义,χ2=23.55,P<0.05。(3)MRI显示椎间盘膨出、突出两组间引起诱发性疼痛无统计学意义,P>0.05。结论椎间盘造影能够显示椎间盘纤维环放射性撕裂、内环或外环破裂以及髓核碎裂等病理改变,可作为除MRI外的一个较好的补充检查方法,同时椎间盘造影时所引起的诱发性疼痛和临床下腰痛有较高相关性,因而对判断引起疼痛的椎间盘定位具有较高的诊断价值。

MRI检查时紧张综合征的心理护理

目的探讨MRI检查时紧张综合征的心理护理。方法对252例进行MRI检查时出现紧张综合征的患者进行心理分析,并针对不同类型的心理障碍给予相应的心理护理。结果252例检查时紧张综合征的患者中有16例因疾病原因及严重心理障碍取消检查,其余236例患者按照心理障碍分为3种类型,并给予相应的心理护理后能够顺利配合完成检查。结论在进行MRI检查时,给予类似患者针对性的心理护理,是确保MRI检查顺利完成的重要环节。

经验胸部MRI在肺癌放疗中的应用价值分析

探究胸部核磁共振成像(MRI)应用于肺癌放疗中的临床价值。选取就治肺癌患者33例,对其进行同期MRI检查和CT检查,将数据分为CT检查的对照组及MRI检查的试验组,检查进行时间分别为放疗前后。检查结束对两组数据进行比对分析。对照组误差率远高于试验组,差异均有统计学意义(P<0.05)。胸部MRI在肺癌放疗前后均能对肺癌相关病症指标及临床预后情况做出较为准确的判断,误差率远小于CT检查,具有良好应用价值和临床推广意义。