Magnetic resonance imaging with three-dimensional fast imaging employing steady-state acquisition with phase-cycled and short T1 inversion recovery pulse sequence for evaluating brachial plexus injury

There is a large amount of fat in the postganglionic segment of the brachial plexus nerve.The use of short T1 inversion recovery pulse sequence may improve signal strength of the brachial plexus postganglionic segment.The present study revealed that the combination of three-dimensional fast imaging employing steady-state acquisition with phase-cycled and short T1 inversion recovery pulse sequence clearly displayed the anatomical morphology and structure of the brachial plexus nerve,together with maximum intensity projection,volume rendering and other three-dimensional reconstruction techniques.Our results suggested that this method is also suitable for providing accurate assessment and diagnosis of the site,severity and scope of brachial plexus injury.

Dedicated Magnetic Resonance Imaging Sequences:Contribution in the Diagnosis of Focal Epilepsy in the Lebanese Population

There have been many advances in the diagnosis and management of focal epilepsies particularly with neuroimaging techniques and magnetic resonance imaging(MRI).Special MRI sequences can be employed to localize and resect the epileptogenic lesions responsible for focal epilepsy.This study aims to show the benefit of dedicated epilepsy MRI sequences in the diagnosis of focal epilepsies.A general electric 1.5 Tesla MRI machine was used with standard and special sequences.Also,a Nihon Kohden electroencephalography(EEG)machine was used.This is a prospective observational study that included 51 patients with focal epilepsies who had an initial negative brain imaging.They underwent epilepsy MRI sequences along with a prolonged video EEG monitoring to localize the lesion,and then results were analyzed statistically using SPSS 22 program.The majority of patients were males(62.75%)with a mean age of 30 years.The grand majority of patients(74.5%,p value of 0.001)had their lesion localized by the epilepsy MRI.The most commonly found pathology was mesial temporal sclerosis.A significant number of patients(23.5%)were sent for an epilepsy surgery(p value 0.002).This study shows the significant impact of dedicated epilepsy MRI sequences on the diagnosis and management of focal epilepsy in the Lebanese population.

Feasibility of 3.0 T diffusion-weighted nuclear magnetic resonance imaging in the evaluation of functional recovery of rats with complete spinal cord injury

Diffusion tensor imaging is a sensitive way to reflect axonal necrosis and degeneration, glial cell regeneration and demyelination following spinal cord injury, and to display microstructure changes in the spinal cord in vivo. Diffusion tensor imaging technology is a sensitive method to diagnose spinal cord injury; fiber tractography visualizes the white matter fibers, and directly displays the structural integrity and resultant damage of the fiber bundle. At present, diffusion tensor imaging is restricted to brain examinations, and is rarely applied in the evaluation of spinal cord injury. This study aimed to explore the fractional anisotropy and apparent diffusion coefficient of diffusion tensor magnetic resonance imaging and the feasibility of diffusion tensor tractography in the evaluation of complete spinal cord injury in rats. The results showed that the average combined scores were obviously decreased after spinal cord transection in rats, and then began to increase over time. The fractional anisotropy scores after spinal cord transection in rats were significantly lower than those in normal rats （P 〈 0.05）; the apparent diffusion coefficient was significantly increased compared with the normal group （P 〈 0.05）. Following spinal cord transection, fractional anisotropy scores were negatively correlated with apparent diffusion coefficient values （r = -0.856, P 〈 0.01）, and positively correlated with the average combined scores （r = 0.943, P 〈 0.01）, while apparent diffusion coefficient values had a negative correlation with the average combined scores （r = -0.949, P 〈 0.01）. Experimental findings suggest that, as a non-invasive examination, diffusion tensor magnetic resonance imaging can provide qualita- tive and quantitative information about spinal cord injury. The fractional anisotropy score and apparent diffusion coefficient have a good correlation with the average combined scores, which reflect functional recovery after spinal cord injury.

Optimization of hepatobiliary phase delay time of Gd-EOB-DTPA-enhanced magnetic resonance imaging for identification of hepatocellular carcinoma in patients with cirrhosis of different degrees of severity

AIM To optimize the hepatobiliary phase delay time(HBPDT) of Gd-EOB-DTPA-enhanced magnetic resonance imaging(GED-MRI) for more efficient identification of hepatocellular carcinoma(HCC) occurring in different degrees of cirrhosis assessed by Child-Pugh(CP) score.METHODS The liver parenchyma signal intensity(LPSI), the liver parenchyma(LP)/HCC signal ratios, and the visibility of HCC at HBP-DT of 5, 10, 15, 20, and 25 min(i.e., DT-5, DT-10, DT-15, DT-20, and DT-25) after injection of GdEOB-DTPA were collected and analyzed in 73 patients with cirrhosis of different degrees of severity(including 42 patients suffering from HCC) and 18 healthy adult controls.RESULTS The LPSI increased with HBP-DT more significantly in the healthy group than in the cirrhosis group(F = 17.361, P < 0.001). The LP/HCC signal ratios had a significant difference(F = 12.453, P < 0.001) among various HBP-DT points, as well as between CP-A and CP-B/C subgroups(F = 9.761, P < 0.001). The constituent ratios of HCC foci identified as obvious hypointensity(+++), moderate hypointensity(++), and mild hypointensity or isointensity(+/-) kept stable from DT-10 to DT-25: 90.6%, 9.4%, and 0.0% in the CP-A subgroup; 50.0%, 50.0%, and 0.0% in the CP-B subgroup; and 0.0%, 0.0%, and 100.0% in the CP-C subgroup, respectively.CONCLUSION The severity of liver cirrhosis has significant negative influence on the HCC visualization by GED-MRI. DT-10 is more efficient and practical than other HBP-DT points to identify most of HCC foci emerging in CP-A cirrhosis, as well as in CP-B cirrhosis; but an HBP-DT of 15 min or longer seems more appropriate than DT-10 for visualization of HCC in patients with CP-C cirrhosis.

Apert syndrome diagnosed by prenatal ultrasound combined with magnetic resonance imaging and whole exome sequencing:A case report

BACKGROUND Most cases of Apert syndrome(AS)are found after birth.Cases of AS diagnosed by ultrasound combined with magnetic resonance imaging(MRI)and whole exome sequencing(WES)during pregnancy are rare.CASE SUMMARY We present the case of a 34-year old female patient(gravida 2,para 1)whose fetus was diagnosed with AS during pregnancy.Fetal ultrasound performed at 30,2/7 wk of pregnancy showed abnormalities.MRI and three-dimensional ultrasound performed at 31,1/7 wk of pregnancy showed the possibility of AS.Chromosome examination and core family WES were conducted at 31,5/7 wk of pregnancy.The results showed that FGFR2 in the fetus had a c.755C>G missense mutation in its nucleotide,and AS was confirmed.CONCLUSION This case highlights the importance of imaging examinations.Prenatal ultrasound combined with MRI can identify fetal morphological abnormalities accurately,which can be confirmed by WES.

A Prediction Model for Detecting Dysthyroid Optic Neuropathy Based on Clinical Factors and Imaging Markers of the Optic Nerve and Cerebrospinal Fluid in the Optic Nerve Sheath

Objective This study aimed to develop and test a model for predicting dysthyroid optic neuropathy(DON)based on clinical factors and imaging markers of the optic nerve and cerebrospinal fluid(CSF)in the optic nerve sheath.Methods This retrospective study included patients with thyroid-associated ophthalmopathy(TAO)without DON and patients with TAO accompanied by DON at our hospital.The imaging markers of the optic nerve and CSF in the optic nerve sheath were measured on the water-fat images of each patient and,together with clinical factors,were screened by Least absolute shrinkage and selection operator.Subsequently,we constructed a prediction model using multivariate logistic regression.The accuracy of the model was verified using receiver operating characteristic curve analysis.Results In total,80 orbits from 44 DON patients and 90 orbits from 45 TAO patients were included in our study.Two variables(optic nerve subarachnoid space and the volume of the CSF in the optic nerve sheath)were found to be independent predictive factors and were included in the prediction model.In the development cohort,the mean area under the curve(AUC)was 0.994,with a sensitivity of 0.944,specificity of 0.967,and accuracy of 0.901.Moreover,in the validation cohort,the AUC was 0.960,the sensitivity was 0.889,the specificity was 0.893,and the accuracy was 0.890.Conclusions A combined model was developed using imaging data of the optic nerve and CSF in the optic nerve sheath,serving as a noninvasive potential tool to predict DON.

Generalized Nonconvex Low-Rank Algorithm for Magnetic Resonance Imaging (MRI) Reconstruction

In recent years,utilizing the low-rank prior information to construct a signal from a small amount of measures has attracted much attention.In this paper,a generalized nonconvex low-rank(GNLR) algorithm for magnetic resonance imaging(MRI)reconstruction is proposed,which reconstructs the image from highly under-sampled k-space data.In the algorithm,the nonconvex surrogate function replacing the conventional nuclear norm is utilized to enhance the low-rank property inherent in the reconstructed image.An alternative direction multiplier method(ADMM) is applied to solving the resulting non-convex model.Extensive experimental results have demonstrated that the proposed method can consistently recover MRIs efficiently,and outperforms the current state-of-the-art approaches in terms of higher peak signal-to-noise ratio(PSNR) and lower high-frequency error norm(HFEN) values.

Design of small-scale gradient coils in magnetic resonance imaging by using the topology optimization method

A topology optimization method based on the solid isotropic material with penalization interpolation scheme is utilized for designing gradient coils for use in magnetic resonance microscopy.Unlike the popular stream function method,the proposed method has design variables that are the distribution of conductive material.A voltage-driven transverse gradient coil is proposed to be used as micro-scale magnetic resonance imaging(MRI)gradient coils,thus avoiding introducing a coil-winding pattern and simplifying the coil configuration.The proposed method avoids post-processing errors that occur when the continuous current density is approximated by discrete wires in the stream function approach.The feasibility and accuracy of the method are verified through designing the z-gradient and y-gradient coils on a cylindrical surface.Numerical design results show that the proposed method can provide a new coil layout in a compact design space.

Improved neurological diagnoses and treatment strategies via automated human brain tissue segmentation from clinical magnetic resonance imaging

Objective Segmentation of medical images is a crucial process in various image analysis applications.Automated segmentation methods excel in accuracy when compared to manual segmentation in the context of medical image analysis.One of the essential phases in the quantitative analysis of the brain is automated brain tissue segmentation using clinically obtained magnetic resonance imaging(MRI)data.It allows for precise quantitative examination of the brain,which aids in diagnosis,identification,and classification of disorders.Consequently,the efficacy of the segmentation approach is crucial to disease diagnosis and treatment planning.Methods This study presented a hybrid optimization method for segmenting brain tissue in clinical MRI scans us-ing a fractional Henry horse herd gas optimization-based Shepard convolutional neural network(FrHHGO-based ShCNN).To segment the clinical brain MRI images into white matter(WM),grey matter(GM),and cerebrospinal fluid(CSF)tissues,the proposed framework was evaluated on the Lifespan Human Connectome Projects(HCP)database.The hybrid optimization algorithm,FrHHGO,integrates the fractional Henry gas optimization(FHGO)and horse herd optimization(HHO)algorithms.Training required 30 min,whereas testing and segmentation of brain tissues from an unseen image required an average of 12 s.Results Compared to the results obtained with no refinements,the Skull stripping refinement showed significant improvement.As the method included a preprocessing stage,it was flexible enough to enhance image quality,allowing for better results even with low-resolution input.Maximum precision of 93.2%,recall of 91.5%,Dice score of 91.1%,and F1-score of 90.5% were achieved using the proposed FrHHGO-based ShCNN,which was superior to all other approaches.

高分辨率磁共振成像对臂丛神经损伤的预测价值

目的探析高分辨率磁共振(MRI)成像对臂丛神经损伤(brachial plexus injury,BPI)的预测价值。方法对59例临床拟诊BPI的病例行高分辨MRI检查。根据年龄,将年龄≥65岁者纳入老年组,18~64岁者纳入青中年组。观察两组臂丛神经显像效果,计算臂丛神经成像评分、臂丛神经信噪比(signal-to-noise ratio,SNR)、对比度噪声比(contrast-to-noise ratio,CNR)和背景抑制评分,分析高分辨率MRI成像对不同年龄段BPI的预测价值。结果59例临床拟诊BPI病例中,MRI诊断为BPI 20例,其余正常。20例经MRI确诊BPI中,老年组7例和青中年组13例。老年组节前损伤2例(28.57%),节后损伤5例(71.43%);青中年组节前损伤5例(38.46%),节后损伤8例(61.54%)。两组病人臂丛神经成像评分由低到高依次为三维双回波稳态(3D-DESS)序列增强扫描、三维短时反转恢复快速自旋回波(3D SPACE)序列平扫、DESS序列平扫和SPACE序列增强扫描,且在干3、支5 DESS序列平扫、股6 DESS序列增强扫描及支5 SPACE序列增强扫描上,老年组臂丛神经成像评分明显低于青中年组(P<0.05)。两组SNR、CNR由低到高依次为DESS增强、SPACE平扫、DESS平扫和SPACE增强(P<0.05),两组背景组织抑制评分比较,SPACE增强最高,其次为DESS平扫,DESS增强和SPACE平扫最低(P<0.05)。老年组DESS序列增强扫描的SNR、CNR以及SPACE序列平扫、增强扫描的SNR、CNR均明显低于青中年组(P<0.05)。结论与青中年BPI病人相比,老年BPI病人臂丛神经成像评分、SNR与CNR更低,MRI 3D SPACE序列可清晰显示臂丛神经内部信号改变,同时降低神经周围背景组织信号干扰,对于显示神经损伤优势明显,值得临床优先选择。

三维多回波聚合梯度回波序列在腰骶丛成像中的初步应用

目的 探讨3D多回波聚合梯度回波序列(3D GEMEC)在腰骶丛神经成像中的应用价值。方法 回顾性分析2022年8~9月六安市人民医院以腰腿疼为主诉的32例住院患者的影像学资料,男15例,女17例,年龄28~78(60.1±15.8)岁。在不同1.5T平台上分别完成腰骶丛3D GEMEC序列和三维T2加权快速梯度回波(3D T2 FFE)序列,比较两种序列腰骶丛神经的信噪比、对比噪声比和主观显示效果。结果 3D GEMEC序列腰骶丛神经的信噪比、对比噪声比以及主观显示效果与3D T2 FFE序列的差异均无统计学意义(P=0.250、0.146、0.083)。结论 3D GEMEC序列可以清晰地显示腰骶丛神经的解剖结构并抑制背景信号,在腰骶丛神经病变的诊断方面具有一定的临床应用前景。

心脏磁共振影像组学对肥厚型心肌病的价值研究

目的初步探索基于心脏磁共振(cardiovascular magnetic resonance,CMR)影像组学揭示肥厚型心肌病(hypertrophic cardiomyopathy,HCM)患者心肌病变影像组学特征的临床应用价值。材料与方法回顾性分析宁夏医科大学总医院2018年1月1日至2022年12月31日确诊为HCM的患者142例及健康对照组72例的CMR影像及临床资料。选择CMR未增强亮血电影序列左心室长轴位两腔心、四腔心二尖瓣口水平切面,以舒张末期壁厚(end-diastolic wall thickness,EDWT)为基础,将HCM患者心肌分为肥厚区域(无HCM家族史,EDWT≥15 mm;有HCM家族史,EDWT≥13 mm)与非肥厚区域(无HCM家族史,EDWT<15 mm;有HCM家族史,EDWT<13 mm),和健康对照组在室间隔、心尖、左心室侧壁、左心室前壁及左心室下壁等相同解剖部位室壁分别进行感兴趣区(region of interest,ROI)勾画及影像组学特征提取,分组后行影像组学特征组间比较。采用Mann-Whitney U检验、递归特征消除法(recursive feature elimination,RFE)及最小绝对收缩与选择算法(least absolute shrinkage and selection operator,LASSO)进行影像组学特征筛选并使用支持向量机(supportvector machine,SVM)算法建立影像组学模型,最后计算准确度、敏感度、特异度、阳性预测值(positive predictive value,PPV)、阴性预测值(negative predictive value,NPV)受试者操作特征曲线下面积(area under the curve,AUC),分别评价各模型效能;并统计分析HCM患者及健康对照组临床资料。结果(1)HCM组的左心室收缩末期容积(left ventricular end systolic volume,LVESV)、LVESV指数(LVESV index,LVESVI)、左心室舒张末期室壁质量(left ventricular end diastolic wall mass,LVED wall mass)、左心室舒张末期室壁+乳头肌质量(left ventricular end diastolic wall+papillary mass,LVED wall+papillary mass)、左心室收缩末期室壁质量(left ventricular end systolic wall mass,LVES wall mass)、左心室收缩末期室壁+乳头肌质量(left ventricular end systolic wall+papillary mass,LVES wall+papillary mass)、舒张末期左室壁最大厚度(left ventricular maximum wall thickness,LVMWT)均高于健康对照组(P<0.05)。(2)HCM患者肥厚区域、非肥厚区域与健康对照组左心室相同解剖部位室壁影像组学鉴别模型鉴别效果良好;HCM非肥厚区域组(左心室前壁)与HCM肥厚区域组(左心室前壁)影像组学鉴别模型为本研究的最优模型,其AUC值、准确度、敏感度、特异度、PPV及NPV在训练集中为0.98、93%、94%、92%、89%、96%;在测试集中为0.97、94%、92%、96%、92%、96%。结论影像组学可通过深入全面的定量分析HCM患者不同病变状态心肌组织,为评估HCM患者心肌组织学改变提供客观敏感的新方法,有助于更准确地评估HCM患者病情、提高CMR检查效率及减少检查费用,有望为探寻方便快捷检测心肌组织学状态的人工智能技术开发及临床应用提供新思路。

磁共振常规序列联合DWI序列用于肛瘘术前诊断准确性分析

目的 探讨磁共振(MRI)常规序列联合弥散加权成像(DWI)序列用于肛瘘术前诊断准确性分析。方法 选取本院2020年5月到2022年8月肛瘘患者78例,所有患者均接受MRI常规及DWI序列扫描,对比MRI-DWI、常规序列扫描对外口、内口、主瘘管、分支瘘管、脓腔检出率及肛瘘Parks分型准确率,通过受试者工作曲线(ROC)评估表观扩散系数(ADC值)对病灶活动度的评估价值。结果 手术病理证实的78例肛瘘患者中,分别检出外口192个、内口88个、主瘘管78个、分支瘘管156个、脓腔60个,MRI-DWI对外口、内口、主瘘管、分支瘘管、脓腔的检出率分别为86.98%、89.77%、 87.18%、80.13%、81.67%高于单纯MRI常规序到78.13%、73.86%、71.79%、67.31%、63.33%(P<0.05);78例肛瘘患者parks分型包括Ⅰ型30、Ⅱ型25例、Ⅲ型14例、Ⅳ型9例;MRI-DWI对肛瘘parks分型Ⅰ型、Ⅱ型、Ⅲ型、Ⅳ型的诊断与病理结果的一致性Kappa值分别为0.833、0.769、0.788、0.820,均>0.75,二者一致性均较好,MRI-DWI对肛瘘prks分型Ⅰ型、Ⅱ型、Ⅲ型、Ⅳ型诊断准确率分别为92.31%、87.74%、93.59%、96.15%均高于单纯MRI常规序列诊断准确率7.654%、74.36%、79.49%、88.46%,总体准确率为85.90%高于MRI常规序列58.97%(P<0.05);78例患者肛瘘病灶活动度包括活动期29例,缓解期49例,缓解期患者ADC值高于活动期患者(P<0.05);ROC曲线分析显示ADC值评价肛瘘病变活动性曲线下面积0.908,灵敏度82.80%,特异度85.70%。结论 MRI-DWI诊断肛瘘有较高应用价值,Parks分型准确,对疾病活动度的评估价值较高,可准确检测出肛瘘内口、外口、主瘘管、分支瘘管和脓腔等。

头颈联合3D-TOF-MRA人工智能辅助压缩感知序列的优化

目的通过比较施加不同加速因子(acceleration factors,AF)的并行采集(parallel imaging,PI)、压缩感知(compressed sensing,CS)、人工智能-压缩感知(artificial intelligence compressed sensing,ACS)技术的头颈联合三维时间飞跃法磁共振血管成像(three-dimensional time-of-fight magnetic resonance angiography,3D-TOF-MRA)的图像质量,选取优化序列。材料与方法前瞻性招募24例健康志愿者,以PI的AF为3(PI 3)、CS的AF分别为4和6(CS 4、CS 6)以及ACS的AF分别为4、6、8、10(ACS 4、ACS 6、ACS 8、ACS 10)进行头颈联合3D-TOF-MRA扫描。扫描时间:PI 3=8 min 40 s;CS 4=6 min 38 s;CS 6=4 min 9 s;ACS 4=5 min 24 s;ACS 6=4 min 30 s;ACS 8=4 min 13 s;ACS 10=3 min 24 s。分别在双侧大脑中动脉(middle cerebral artery,MCA)M1段、双侧颈内动脉(internal carotid artery,ICA)C4段、颈动脉分叉处下5个层面的双侧颈总动脉(common carotid artery,CCA)以及MCA及ICA同一层面的颞叶白质,CCA同一层面的胸锁乳突肌作为背景区域勾画感兴趣区(regions of interest,ROI),记录信号强度(signal intensity,SI)及标准差(standard deviation,SD),从而计算信噪比(signal-to-noise ratio,SNR)与对比噪声比(contrast-to-noise ratio,CNR)。采用四分法和五分法分别对整体图像质量以及颅内动脉、颈部大动脉进行评分。以组内相关系数(intra-class correlation coefficient,ICC)比较两名放射医师之间及同一名放射医师内客观评价结果的一致性,Kappa检验比较两名放射医师之间及同一名放射医师内主观评价结果的一致性,若一致性良好,则选取其中一位医师的客观评分及主观评分进行后续统计分析。采用单因素方差分析或Kruskal-Wallis检验对客观评分以及主观评分进行总体差异比较,若差异具有统计学意义则进行两两比较。结果与PI技术比较显示,ACS 4~ACS 8的SNR_(L-MCA),ACS 8、ACS 10的CNR_(L-MCA),ACS 4、ACS 6、ACS 10的CNR_(R-MCA),ACS 4~ACS 10的SNR_(R-MCA)、SNR_(L-CCA)、CNR_(L-CCA),ACS 6~ACS 10的SNR_(R-CCA)、CNR_(R-CCA)均高于PI 3,差异具有统计学意义(P<0.05)。与CS技术比较显示,ACS 4~ACS 10的SNR_(R-MCA)、CNR_(L-MCA)及CNR_(R-MCA),ACS 4~ACS 8的SNR_(L-MCA)、SNR_(L-CCA)、SNR_(R-CCA)、CNR_(L-CCA)、CNR_(R-CCA)与CS 4差异具有统计学意义(P<0.05),ACS 4~ACS 10的SNR_(L-MCA)、SNR_(R-MCA)、CNR_(L-MCA)、CNR_(R-MCA)、SNR_(L-ICA)、SNR_(R-ICA)、CNR_(L-ICA)、SNR_(L-CCA)、SNR_(R-CCA)、CNR_(L-CCA)、CNR_(R-CCA)与CS 6差异具有统计学意义(P<0.05),均优于CS 4、CS 6。ACS技术之间两两比较,ACS 8的SNR_(L-MCA)高于ACS 10(P<0.05),ACS 8、ACS 10的SNR_(R-CCA)、CNR_(R-CCA)均高于ACS 4(P<0.05),其余差异均无统计学意义(P>0.05)。除颈部大动脉图像外,主观评分统计结果均为ACS 4~ACS 10与CS 6差异具有统计学意义(P<0.05),优于CS 6。结论与PI及CS技术相比,ACS技术拥有更短的扫描时间,更好的图像质量。ACS 8为最优序列,扫描时间比PI 3缩短51%。

心脏磁共振短轴电影成像影像组学鉴别肥厚型心肌病与健康对照

目的·分析肥厚型心肌病(hypertrophic cardiomyopathy,HCM)患者与健康对照人群的心脏磁共振(cardiac magnetic resonance,CMR)短轴电影(cine)成像影像组学特征差异,并对2类人群进行分类。方法·纳入2018年1月—2021年12月就诊于上海交通大学医学院附属仁济医院心内科的HCM患者100例,以2∶1比例随机选取同时期健康对照(healthy control,HC)50例,在放射科医师规范操作下完成CMR检查。通过CVI 42后处理软件完成对入组人员左心室心功能及形态学的测量与评估,主要包括左心室射血分数(left ventricular ejection fraction,LVEF)、舒张末期左心室容积(left ventricular end-diastolic volume,LVEDV)和舒张末期左心室心肌质量(left ventricular end-diastolic mass,LVEDM)。并从CMR短轴电影成像中获取舒张末期心肌区域3D影像组学特征。分析影像组学特征在2类人群中的分布,并构建机器学习模型对2类人群进行分类。结果·共提取3D影像组学特征107个。在排除高度一致的特征后采用最小绝对值收敛和选择算子(least absolute shrinkage and selection operator,LASSO)模型进行5折交叉验证后,仍有11个系数非0的特征;利用K-best方法选择排序靠前的8个用于后续建模分析,其中4个特征在2组人群中差异具有统计学意义(均P<0.05)。随后构建支持向量机(support vector machine,SVM)和随机森林(random forest,RF)模型用于判别2类人群。结果显示:单一特征模型(一阶:熵)最大曲线下面积(area under the curve,AUC)为0.833(95%CI 0.695~0.968);多特征模型(SVM算法)最高准确率为83.3%,其对应的AUC为0.882(95%CI 0.705~0.980)。结论·HCM患者与HC人群在左心室功能和左心室形态上均有显著差异,同时3D心肌影像组学特征也有显著差异。尽管单一特征模型可以鉴别2类人群,但联合多特征构建的模型有更好的分类效果。

钆对比剂剂量对增强T2 FLAIR序列与增强T1WI序列脑转移瘤强化效果的影响及对比研究

目的 对比不同剂量钆对比剂注射后增强液体衰减反转恢复(contrast enhanced T2 fluid attenuated inversion recovery,CE-T2 FLAIR)序列与对比增强T1WI(contrast enhanced T1WI, CE-T1WI)上脑转移瘤的强化效果,探讨半剂量对比剂条件下CE-T2 FLAIR序列在脑转移瘤MRI检查的诊断价值。材料与方法 前瞻性纳入颅外原发恶性肿瘤经病理学明确诊断、脑转移瘤经病理或临床随访证实的患者30例,于3.0 T MRI设备行头颅MRI增强扫描,在常规平扫序列的基础上,行半剂量(0.05 mmol/kg)CE-T2 FLAIR和CE-T1WI扫描,随后分次补充钆对比剂达常规剂量(0.1 mmol/kg)后至双倍剂量(0.2 mmol/kg),在注射对比剂后均进行CE-T2 FLAIR和CE-T1WI扫描。由两位观察者对三次扫描的CE-T2 FLAIR和CE-T1WI图像进行客观测量。计算不同剂量条件下CE-T2 FLAIR和CE-T1WI图像的对比信噪比(contrast to noise ratio, CNR)、相对对比度(relative contrast, RC)及百分比增加(percentage increase, PI)。采用方差分析对客观测量结果进行组间比较,差异有统计学意义(P<0.05)时进行后续多重比较;采用t检验比较两组之间的差异。结果 两位观察者客观评分一致性良好。三组对比剂剂量下CE-T2 FLAIR图像间CNR值与RC值差异无统计学意义(P>0.05);与平扫T2 FLAIR相比,病灶PI增高,增强效果良好。三组对比剂剂量下CE-T1WI图像间CNR值与RC值差异有统计学意义(P<0.05),两两比较结果表明双倍剂量CE-T1WI图像上CNR值及RC值均明显大于半剂量组(P<0.05)。半剂量及常规剂量CE-T2 FLAIR图像CNR值及RC值上均较该组CE-T1WI明显增大,差异有统计学意义(P<0.05)。半剂量CE-T2 FLAIR图像CNR值及RC值均明显大于常规剂量CE-T1WI(P<0.05)。与双倍剂量CE-T1WI相比,半剂量CE-T2 FLAIR图像CNR值增大(P<0.05),RC值差异无统计学意义(P>0.05)。结论 半剂量对比剂下CE-T2FLAIR图像上脑转移瘤的强化效果与常规CE-T1WI相仿,病灶显示良好,为半剂量对比剂的CE-T2 FLAIR序列应用于脑转移瘤MRI检查提供依据。

骨质疏松椎体骨折磁共振STIR信号改变与CT骨折线类型的关系

目的探讨骨质疏松椎体骨折磁共振(MRI)-短反转时间反转恢复序列(STIR)信号改变与电子计算机断层扫描(CT)骨折线类型的关系。方法回顾性分析收治的108例骨质疏松椎体骨折患者临床资料以及MRI、CT影像学征象。比较不同MRI-STIR信号改变患者的CT骨折线类型及CT值。结果经MRI检查,入组患者骨折椎体数共121节,STIR序列呈现黑色线信号45节,无同源高信号36节,同源高信号40节;CT显示,骨折线嵌插型51节,开裂型33节,微骨折型37节。MRI-STIR序列呈现黑色线信号的患者椎体CT骨折线为嵌插型阳性率高于无同源高信号和同源高信号,差异有统计学意义(P<0.05);MRI-STIR序列呈现同源高信号的患者椎体CT骨折线为微骨折型阳性率高于黑色线信号和无同源高信号,差异有统计学意义(P<0.05)。MRI-STIR序列呈现黑色线信号的患者椎体CT值低于无同源高信号和同源高信号,差异有统计学意义(P<0.05)。结论MRI-STIR信号改变与CT骨折线类型存在一定相关性。STIR序列呈现黑色线信号的患者出现椎体嵌插型骨折风险更高,且预后较差。

IDEAL-IQ序列在乳腺肿块良恶性鉴别诊断中的应用价值探究

目的 探讨非对称回波最小二乘估算法迭代水脂分离序列(iterative decomposition of water and fat with echo asymmetrical and least-squares estimation quantitation sequence, IDEAL-IQ)来源的R2^(*)值在乳腺良恶性肿瘤鉴别诊断中的价值,并与传统多回波T2^(*)梯度回波(gradient recalled echo, GRE)序列来源的R2^(*)值进行比较。材料与方法 回顾性分析2021年9月至2023年10月在中国医科大学附属第一医院连续收治的42名患者的50个良性肿瘤病灶,在本院影像归档和通信系统(picture archiving and communication systems, PACS)中使用倾向性评分匹配方法匹配肿瘤所在最大层面的最长径,按1∶3的比例纳入150名患者的150个恶性肿瘤病灶。将恶性肿瘤根据预后因子[雌激素受体(estrogen receptor, ER)、孕激素受体(progesterone receptor, PR)以及人表皮生长因子受体2(human epidermal growth factor receptor 2, HER-2)]的阳性/阴性表达情况进行分组。所有患者均接受包含IDEAL-IQ和多回波T2*GRE序列的多参数MRI,测量以下定量参数:IDEAL-IQ序列R2^(*)值(R2^(*)IDEAL)、多回波T2*GRE序列R2^(*)值(R2^(*)GRE)、表观扩散系数(apparent diffusion coefficient, ADC)及肿瘤长径。根据原始资料类型的不同,分别利用单因素分析(独立样本t检验、Mann-Whitney U检验等方法)对比分析各参数的差异。采用Spearman相关性分析R2^(*)IDEAL与R2^(*)GRE及二者与ADC的相关性。采用配对样本t检验比较R2^(*)IDEAL与R2^(*)GRE的差异。采用logistic回归分析建立联合诊断模型,并使用受试者工作特征(receiver operating characteristic, ROC)曲线及曲线下面积(area under the curve,AUC)分析单独及联合参数鉴别乳腺肿瘤良恶性的效能。结果 相关性分析显示乳腺肿瘤患者的R2^(*)IDEAL与R2^(*)GRE呈中度相关(r=0.763,P<0.001),二者与ADC值均呈负性弱相关[r=-0.300(R2^(*)IDEAL),-0.306(R2^(*)GRE),P<0.001]。良性组与恶性组中,R2^(*)IDEAL与R2^(*)GRE均呈中度相关(r=0.745、0.680,P<0.001),二者与ADC均无相关性。两种序列所得的R2^(*)值差异有统计学意义(P<0.001)。R2^(*)IDEAL在良恶性组间差异有统计学意义(P<0.001),管腔HER-2阴性型R2^(*)值最高。对于单一参数,ADC值鉴别良恶性的AUC最高(0.857);对于联合参数,R2^(*)IDEAL+ADC鉴别良性组与管腔阴性组的AUC最高(0.927);差异均有统计学意义(P<0.05)。结论 IDEAL-IQ序列生成的R2^(*)值可用于区分良恶性乳腺肿块,可能成为除ADC外辅助乳腺肿瘤良恶性鉴别的又一无需对比剂参数。

双金属有机骨架在肿瘤诊疗中的研究进展

双金属有机骨架(BMOFs)是以2种不同的金属离子作为节点与有机配体通过配位键连接起来的一类新型杂化材料。BMOFs具有比表面积大、负载量高、组成及孔径可调等优点,可以用作合成具有可控的尺寸、组成和结构的功能纳米材料的模板或前驱体。与单金属MOFs相比,BMOFs在生物医学领域具有更好的离子协同效应、催化选择性和结构稳定性。本综述总结了BMOFs用于肿瘤单一治疗和联合治疗以及在磁共振成像等方面应用的最新研究进展。最后讨论了BMOFs在肿瘤诊疗中存在的挑战和未来发展趋势。

FRACTURE序列在中轴型脊柱关节炎骶髂关节结构性病变中的诊断价值

目的:评估限制回波间隔的快速梯度回波类CT成像(FRACTURE)序列在检测中轴型脊柱关节炎(SpA)骶髂关节结构病变中的诊断价值。方法:回顾性分析83例确诊中轴型SpA患者在2021年12月-2022年8月进行骶髂关节MRI和CT检查的影像资料。评估图像包括FRACTURE、T_(1)WI序列和CT平扫图像。对骶髂关节的影像图像进行结构性病变评分:关节间隙变化(0~5分)、骨质侵蚀(0~3分)和骨质硬化(0~2分)。根据修改后的纽约标准评分系统对骶髂关节炎进行综合评分。结果:总共有166个骶髂关节图像(83名受试者)可供分析。以CT图像作为参考标准,FRACTURE序列在关节间隙改变、骨质侵蚀、骨质硬化和骶髂关节炎综合评分与CT结果表现出较高的一致性,AUC分别为0.908、0.943、0.918和0.944。与T_(1)WI相比,FRACTURE在关节间隙变化(91.8%vs.70.5%)、骨质侵蚀(93.3%vs.56.4%)、骨质硬化(94%vs.77.6%)和骶髂关节炎综合评分(98.9%vs.75.3%)方面具有更高的诊断准确性。结论:FRACTURE成像可以评估中轴型SpA患者骶髂关节的结构性病变,并显示出良好的诊断性能。