Flexible reduced field of view magnetic resonance imaging based on single-shot spatiotemporally encoded technique

In many ultrafast imaging applications, the reduced field-of-view（r FOV） technique is often used to enhance the spatial resolution and field inhomogeneity immunity of the images. The stationary-phase characteristic of the spatiotemporallyencoded（SPEN） method offers an inherent applicability to r FOV imaging. In this study, a flexible r FOV imaging method is presented and the superiority of the SPEN approach in r FOV imaging is demonstrated. The proposed method is validated with phantom and in vivo rat experiments, including cardiac imaging and contrast-enhanced perfusion imaging. For comparison, the echo planar imaging（EPI） experiments with orthogonal RF excitation are also performed. The results show that the signal-to-noise ratios of the images acquired by the proposed method can be higher than those obtained with the r FOV EPI. Moreover, the proposed method shows better performance in the cardiac imaging and perfusion imaging of rat kidney, and it can scan one or more regions of interest（ROIs） with high spatial resolution in a single shot. It might be a favorable solution to ultrafast imaging applications in cases with severe susceptibility heterogeneities, such as cardiac imaging and perfusion imaging. Furthermore, it might be promising in applications with separate ROIs, such as mammary and limb imaging.

Performance study of aluminum shielded room for ultra-low-field magnetic resonance imaging based on SQUID： Simulations and experiments

The aluminum shielded room has been an important part of ultra-low-field magnetic resonance imaging （ULF MRI） based on the superconducting quantum interference device （SQUID）. The shielded room is effective to attenuate the external radio-frequency field and keep the extremely sensitive detector, SQUID, working properly. A high-performance shielded room can increase the signal-to-noise ratio （SNR） and improve image quality. In this study, a circular coil with a diameter of 50 cm and a square coil with a side length of 2.0 m was used to simulate the magnetic fields from the nearby electric apparatuses and the distant environmental noise sources. The shielding effectivenesses （SE） of the shielded room with different thicknesses of aluminum sheets were calculated and simulated. A room using 6-mm-thick aluminum plates with a dimension of 1.5 m x 1.5 m x 2.0 m was then constructed. The SE was experimentally measured by using three-axis SQUID magnetometers, with tranisent magnetic field induced in the aluminum plates by the strong pre-polarization pulses. The results of the measured SE agreed with that from the simulation. In addition, the introduction of a 0.5-mm gap caused the obvious reduction of SE indicating the importance of door design. The nuclear magnetic resonance （NMR） signals of water at 5.9 kHz were measured in free space and in a shielded room, and the SNR was improved from 3 to 15. The simulation and experimental results will help us design an aluminum shielded room which satisfies the requirements for future ULF human brain imaging. Finally, the cancellation technique of the transient eddy current was tried, the simulation of the cancellation technique will lead us to finding an appropriate way to suppress the eddy current fields.

Ultra-high-field magnetic resonance:Why and when?

This paper briefly summarizes the development of magnetic resonance imaging and spectroscopy in medicine.Aspects of magnetic resonancephysics and-technology relevant at ultra-high magnetic fields as well as current limitations are highlighted.Based on the first promising studies,potential clinical applications at 7 Tesla are suggested.Other aims are to stimulate awareness of the potential of ultra-high field magnetic resonance and to stimulate active participation in much needed basic or clinical research at 7 Tesla or higher.

Multi-objective optimization of gradient coil for benchtop magnetic resonance imaging system with high-resolution

Significant high magnetic gradient field strength is essential to obtaining high-resolution images in a benchtop mag- netic resonance imaging （BT-MRI） system with permanent magnet. Extending minimum wire spacing and maximum wire width of gradient coils is one of the key solutions to minimize the maximum current density so as to reduce the local heating and generate higher magnetic field gradient strength. However, maximum current density is hard to optimize together with field linearity, stored magnetic energy, and power dissipation by the traditional target field method. In this paper, a new multi-objective method is proposed to optimize the maximum current density, field linearity, stored magnetic energy, and power dissipation in MRI gradient coils. The simulation and experimental results show that the minimum wire spacings are improved by 159% and 62% for the transverse and longitudinal gradient coil respectively. The maximum wire width increases from 0.5 mm to 1.5 mm. Maximum gradient field strengths of 157 mT/m and 405 mT/m for transverse and lon- gitudinal coil are achieved, respectively. The experimental results in BT-MRI instrument demonstrate that the MRI images with in-plane resolution of 50 ~tm can be obtained by using the designed coils.

3.0 Tesla magnetic resonance imaging: A new standard in liver imaging?

An ever-increasing number of 3.0 Tesla(T) magnets are installed worldwide. Moving from the standard of 1.5 T to higher field strength implies a number of potential advantage and drawbacks, requiring careful optimization of imaging protocols or implementation of novel hardware components. Clinical practice and literature review suggest that state-of-the-art 3.0 T is equivalent to 1.5 T in the assessment of focal liver lesions and diffuse liver disease. Therefore, further technical improvements are needed in order to fully exploit the potential of higher field strength.

Intraoperative magnetic resonance imaging in neurosurgery and anesthetic considerations

Currently, magnetic resonance imaging(MRI) is the only imaging modality available which is capable of acquiring intra-operative images frequently with acceptable spatial and contrast resolution. However, the incorporation of MRI technology into the operating room requires special anesthetic considerations. It may include various aspects such as transport, remote location anesthesia, strong electromagnetic field, use of approved items, equipment counts, possible emergencies, and surgery in awake patients. The patient safety may be compromised by health-related, equipment-related, and procedure-related risks. Direct patient observation may be compromised by acoustic noise, darkened environment, obstructed line of sight, and distractions along with difficult access to the patient for airway management. Most often, the patient's head will be 180° away from the anesthesiologist during the procedure. Several monitors exist that are designed for conditional use in a MR environment. The general design criterion in these monitors is to eliminate conductors that carry electrical signals for monitoring physiologic parameters of the patient. General anesthesia requires an extended anesthetic circuit for ventilation maintenance and drug administration because the patient is located farther from the anesthesia machine than in traditional operating room settings. Dead space creates a time delay before the volatile anesthetic and drugs are administered and when expected effects can be observed. Therefore, the attending anaesthesiologists must understand the above aspects for safe conduct of neurosurgical procedures by minimizing MRI associated accidents while assuring optimal patient vigilance.

Effects of gradient high-field static magnetic fields on diabetic mice

Although 9.4 T magnetic resonance imaging(MRI) has been tested in healthy volunteers,its safety in diabetic patients is unclear.Furthermore,the effects of high static magnetic fields(SMFs),especially gradient vs.uniform fields,have not been investigated in diabetics.Here,we investigated the consequences of exposure to 1.0-9.4 T high SMFs of different gradients(>10 T/m vs.0-10 T/m)on type 1 diabetic(T1D) and type 2 diabetic(T2D) mice.We found that 14 h of prolonged treatment of gradient(as high as 55.5 T/m) high SMFs(1.0-8.6 T) had negative effects on T1D and T2D mice,including spleen,hepatic,and renal tissue impairment and elevated glycosylated serum protein,blood glucose,inflammation,and anxiety,while 9.4 T quasi-uniform SMFs at 0-10 T/m did not induce the same effects.In regular T1D mice(blood glucose>16.7 mmol/L),the>10 T/m gradient high SMFs increased malondialdehyde(P<0.01) and decreased superoxide dismutase(P<0.05).However,in the severe T1D mice(blood glucose≥30.0 mmol/L),the>10 T/m gradient high SMFs significantly increased tissue damage and reduced survival rate.In vitro cellular studies showed that gradient high SMFs increased cellular reactive oxygen species and apoptosis and reduced MS-1 cell number and proliferation.Therefore,this study showed that prolonged exposure to high-field(1.0-8.6 T)>10 T/m gradient SMFs(35-1 380 times higher than that of current clinical MRI)can have negative effects on diabetic mice,especially mice with severe T1D,whereas 9.4 T high SMFs at 0-10T/m did not produce the same effects,providing important information for the future development and clinical application of SMFs,especially high-field MRI.

3.0 T proton magnetic resonance spectroscopy of the liver: Quantification of choline

AIM: To investigate the normal hepatic magnetic resonance spectroscopy findings choline/lipid2 (Cho/Lip2) associated with age and body mass index (BMI).METHODS: A total of 58 single-voxel proton spectra of the liver were acquired at 3.0 T using the eightchannel phased array abdominal coil as the receiver coil. Consecutive stacks of breath-hold spectra were acquired using the point resolved spectroscopy technique at a short echo time of 30 ms and a repetition time of 1500 ms. The spectra were processed with the SAGE software package. Areas and heights for metabolite resonance were obtained. Student's t test for unpaired data was used for comparisons of shimming, Cho/Lip2, and lipid content. RESULTS: There were significant negative correlations between the Cho/Lip2 peak height ratios and BMI (r=-0.615) and age (r=-0.398) (all P<0.01). Compared with the high-BMI group, the low-BMI group was younger (39.1±13.0 years vs 47.6±8.5 years, t=-2.954,P=0.005); had better water suppression (93.4%±1.4% vs 85.6%±11.6%, t=2.741, P=0.014); had higher Cho/Lip2 peak heights ratio (0.2±0.14 vs 0.05±0.04,t=6.033,P<0.000); and had lower lipid content (0.03±0.08 vs 0.29±0.31, t=-3.309, P=0.004). Compared with the older group, the younger group had better shimming effects (17.1±3.6 Hz vs 22.0±6.8 Hz, t=-2.919, P=0.008); higher Cho/Lip2 peak heights ratios (0.03±0.05vs 0.09±0.12,t=2.4, P=0.020); and lower lipid content (0.05±0.11 vs 0.23±0.32,t=-2.337,P=0.031). Compared with the lowcholine peak group, the high-choline peak group had lower lipid content (0.005±0.002 vs 0.13±0.23, t=-3.796,P<0.000); lower BMI (19.6±2.4vs 23.9±3.0, t=-4.410, P<0.000); and younger age (34.7±10.0 years vs 43.2±12.5 years, t=-2.088, P=0.041). CONCLUSION: Lipid accumulation could result from the increased fat in the body depending on age and BMI. Lipid can mask the resonance signal of choline.

Metamaterial-enhanced magnetic resonance imaging:a review

Magnetic resonance imaging(MRI),as a noninvasive and powerful method in modern diagnostics,has been advancing in leaps and bounds.Conventional methods to improve MRI based on increasing the static magnetic field strength are restricted by safety concerns,cost issues,and the impact on patient experience;as such,innovative approaches are required.It has been suggested that metamaterials featuring subwavelength unit cells can be used to take full control of electromagnetic waves and redistribute electromagnetic fields,achieve abundant counterintuitive phenomena,and construct versatile devices.Recently,metamaterials with exotic effective electromagnetic parameters,peculiar dispersion relations,or tailored field distribution of resonant modes have shown promising capabilities in MRI.Herein,we outline the principle of the MRI process,review recent advances in enhancing MRI by employing the unique physical mechanisms of metamaterials,and demystify ways in which metamaterial designs could improve MRI,such as by enhancing the imaging quality,reducing the scanning time,alleviating field inhomogeneities,and increasing patient safety.We conclude by providing our vision for the future of improving MRI with metamaterials.

Impact of cognition-related single nucleotide polymorphisms on brain imaging phenotype in Parkinson’s disease

Multiple single nucleotide polymorphisms may contribute to cognitive decline in Parkinson’s disease. However, the mechanism by which these single nucleotide polymorphisms modify brain imaging phenotype remains unclear. The aim of this study was to investigate the potential effects of multiple single nucleotide polymorphisms on brain imaging phenotype in Parkinson’s disease. Forty-eight Parkinson’s disease patients and 39 matched healthy controls underwent genotyping and 7 T magnetic resonance imaging. A cognitive-weighted polygenic risk score model was designed, in which the effect sizes were determined individually for 36 single nucleotide polymorphisms. The correlations between polygenic risk score, neuroimaging features, and clinical data were analyzed. Furthermore, individual single nucleotide polymorphism analysis was performed to explore the main effects of genotypes and their interactive effects with Parkinson’s disease diagnosis. We found that, in Parkinson’s disease, the polygenic risk score was correlated with the neural activity of the hippocampus, parahippocampus, and fusiform gyrus, and with hippocampal-prefrontal and fusiform-temporal connectivity, as well as with gray matter alterations in the orbitofrontal cortex. In addition, we found that single nucleotide polymorphisms in α-synuclein(SNCA) were associated with white matter microstructural changes in the superior corona radiata, corpus callosum, and external capsule. A single nucleotide polymorphism in catechol-O-methyltransferase was associated with the neural activities of the lingual, fusiform, and occipital gyri, which are involved in visual cognitive dysfunction. Furthermore, DRD3 was associated with frontal and temporal lobe function and structure. In conclusion, imaging genetics is useful for providing a better understanding of the genetic pathways involved in the pathophysiologic processes underlying Parkinson’s disease. This study provides evidence of an association between genetic factors, cognitive functions, and multi-modality neuroimaging biomarkers in Parkinson’s disease.

Role of Electromagnetic Stimulation in the Treatment of Osteonecrosis of the Femoral Head in Early Stages

Osteonecrosis of the femoral head is a disorder that leads to collapse and osteoarthritis in young patients. This study examines the effectiveness of pulsed electromagnetic fields [PEMF] in the treatment of osteonecrosis of the head in precollapse bone stages. A retrospective evaluation was done of 51 patients including 70 hips with symptomatic osteonecrosis of the hip treated with pulsed electromagnetic fields. Criteria for inclusion in the study group were evidence of osteonecrosis and absence of collapse of the femoral head. The average follow-up was 26 months (range, 18 - 90). Etiologies included idiopathic (40 cases), steroid use (26) and alcohol (4). To demonstrate the existence of osteonecrosis and its evolution, magnetic resonance imaging [MRI] and plain radiography techniques were used. Results: Procedures were radiological success in 80% of cases, and no progression to collapse in 88.57% of hips. Eight of the 70 hips had radiographic progression to collapse. This study suggests that selected PEMF reduce the incidence of progression of osteonecrosis of femoral head in early stage.

Theranostic applications:Non-ionizing cellular and molecular imaging through innovative nanosystems for early diagnosis and therapy

Modern medicine is expanding the possibilities of receiving "personalized" diagnosis and therapies,providing minimal invasiveness,technological solutions based on non-ionizing radiation,early detection of pathologies with the main objectives of being operator independent and with low cost to society.Our research activities aim to strongly contribute to these trends by improving the capabilities of current diagnostic imaging systems,which are of key importance in possibly providing both optimal diagnosis and therapies to patients.In medical diagnostics,cellular imaging aims to develop new methods and technologies for the detection of specific metabolic processes in living organisms,in order to accurately identify and discriminate normal from pathological tissues.In fact,most diseases have a "molecular basis" that detected through these new diagnostic methodologies can provide enormous benefits to medicine.Nowadays,this possibility is mainly related to the use of Positron Emission Tomography,with an exposure to ionizing radiation for patients and operators and with extremely high medical diagnosticscosts.The future possible development of non-ionizing cellular imaging based on techniques such as Nuclear Magnetic Resonance or Ultrasound,would represent an important step towards modern and personalized therapies.During the last decade,the field of nanotechnology has made important progress and a wide range of organic and inorganic nanomaterials are now available with an incredible number of further combinations with other compounds for cellular targeting.The availability of these new advanced nanosystems allows new scenarios in diagnostic methodologies which are potentially capable of providing morphological and functional information together with metabolic and cellular indications.

Effect of MR Field Strength on the Texture Features of Cerebral T2-FLAIR Images: A Pilot Study

Objective To investigate effect of MR field strength on texture features of cerebral T2 fluid attenuated inversion recovery(T2-FLAIR)images.Methods We acquired cerebral 3 D T2-FLAIR images of thirty patients who were diagnosed with ischemic white matter lesion(WML)with MR-1.5 T and MR-3.0 T scanners.Histogram texture features which included mean signal intensity(Mean),Skewness and Kurtosis,and gray level co-occurrence matrix(GLCM)texture features which included angular second moment(ASM),Contrast,Correlation,Inverse difference moment(IDM)and Entropy,of regions of interest located in the area of WML and normal white matter(NWM)were measured by ImageJ software.The texture parameters acquired with MR-1.5 T scanning were compared with MR-3.0 T scanning.Results The Mean of both WML and NWM obtained with MR-1.5 T scanning was significantly lower than that acquired with MR-3.0 T(P<0.001),while Skewness and Kurtosis between MR-1.5 T and MR-3.0 T scanning showed no significant difference(P>0.05).ASM,Correlation and IDM of both WML and NWM acquired with MR-1.5 T revealed significantly lower values than those with MR-3.0 T(P<0.001),while Contrast and Entropy acquired with MR-1.5 T showed significantly higher values than those with MR-3.0 T(P<0.001).Conclusion MR field strength showed no significant effect on histogram textures,while had significant effect on GLCM texture features of cerebral T2-FLAIR images,which indicated that it should be cautious to explain the texture results acquired based on the different MR field strength.

7T超高场磁共振颅内血管壁成像在缺血性脑卒中病因分型中的研究进展

缺血性脑卒中的病因分型对临床治疗决策和预后判断有重要价值。近年来,随着高分辨率磁共振血管壁成像(high-resolution vessel wall magnetic resonance imaging,HR-VW-MRI)在脑卒中临床研究和实践中的应用增加,7 T MRI以其更高信噪比和更优图像质量,可发现脑血管早期、细微的病理变化,为深入了解各种脑血管疾病的病理机制提供了新思路。然而,超高场强也存在B1场不均、扫描时间长等技术挑战。本文就7 T HR-VW-MRI在缺血性卒中病因分型及临床应用中的进展进行综述,深入分析7 T HR-VW-MRI在提升临床诊断精确性与指导临床治疗中的潜在价值,为临床实践与科研探索提供参考。

基于不同维度低场核磁共振技术的大豆含油率检测与判别

大豆含油率的高低直接影响榨油与育种结果。为探究大豆含油率的最佳检测方法与构建含油率高低判别模型,该研究基于不同维度低场核磁共振(low field nuclear magnetic resonance,LF-NMR)技术,以国标法为对照,利用LF-NMR波谱和LF-NMR含油含水率软件检测大豆含油率;核磁共振成像(magnetic resonance imaging,MRI)结合深度学习,建立大豆含油率高低判别模型。引入低场二维核磁共振(low field two-dimensional nuclear magnetic resonance,LF-2D-NMR)技术,定性分析一维波谱中信号重叠无法区分组分的问题。试验结果表明,LF-NMR含油含水率软件能快速准确检测大豆含油率,T1-T2二维核磁图谱成功解决了自由水和油信号重叠问题。利用U-net++深度学习模型对MRI成像的矢状面、冠状面、横截面以及三面混合数据集进行训练,其中横截面评价指标与其他数据集相比更优,语义分割部分中平均交并比(mean intersection over union,mIoU)约0.9058,全局准确率0.9980,训练后的模型能够将MRI图像识别并分割,快速判别大豆含油率高低。试验证明,LF-NMR及MRI能够快速无损掌握大豆含油率信息,为大豆的高油育种提供了新思路和技术支持。

7T磁共振成像在脑小血管病中的应用进展

脑小血管病在老年人群具有很高的发病率,可显著增加脑卒中和痴呆的发生风险。迄今为止,该疾病尚无有效的临床和体液生物标志物,诊断鉴别高度依赖于MRI。然而,由于临床影像的空间分辨率所限,脑小血管损害难以直接评价,因此研究者们主要使用一些反映脑实质损害的影像标志物来评估小血管损伤。近年来,随着超高场(7T)MRI技术的不断成熟,其在脑小血管病领域的研究亦日趋广泛。7T-MRI能够直接评估脑小血管结构、功能,并显著提高微小脑实质病灶的检测敏感性,为脑小血管病机制研究和精准诊断提供了重要工具。本文将回顾近年来基于7T-MRI的脑小血管病研究,并讨论潜在的问题和未来研究方向,为相关研究工作者提供借鉴。

5.0T MRI临床应用价值与研究进展

5.0T MR成像平台通过创新性设计解决了传统超高场强设备存在的图像信号不均匀、全身成像难等技术问题,使图像质量得以显著提高。目前5.0T MRI已在神经系统、心血管系统、骨骼肌肉系统及腹部成像中展现出巨大潜力,并已衍生出多种相关创新性技术。本文就5.0T MRI的临床应用价值及其研究进展进行述评。

多模态高场MRI乳腺扫描对乳腺良恶性病变的诊断价值

目的 分析多模态高场磁共振成像(MRI)乳腺扫描诊断乳腺良恶性病变的临床价值。方法 收集2022年1月至2023年12月于河南科技大学第二附属医院进行乳腺MRI检查的79例乳腺患者的临床资料,所有患者入院后均接受高场MRI轴位T1加权成像(T1WI)、压脂T2加权成像(fs-T2WI)、扩散加权成像(DWI)、表观弥散系数(ADC)、动态对比增强(DCE),并将扫描的图像传至配套的后处理软件工作站建立病灶感兴趣区的动态增强曲线(DCE-TIC)及最大强度投影(MIP)图像、分析多模态高场MRI乳腺扫描在诊断乳腺良恶性病变方面的临床价值。结果 以组织病理学检查结果作为金标准,79例患者中发现81个病灶,其中良性病变44个,恶性病变37个,有2例患者存在2个病变并存的情况,1例是左乳纤维腺瘤,右乳微小粘液癌,1例是左乳发现2个病变,血管平滑肌瘤和叶状肿瘤并存。磁共振平扫、动态对比增强扫描和多模态高场MRI乳腺扫描诊断恶性病变的灵敏度分别为72.97%、86.49%、94.59%,特异度分别为54.55%、59.09%、81.82%,准确度分别为62.96%、71.60%、87.65%,约登指数分别为0.28、0.46、0.76。其中多模态高场MRI乳腺扫描诊断乳腺恶性病变效能最高,灵敏度、特异度、准确度及约等指数分别为94.59%、81.82%、87.65%,0.76,高于单一做乳腺磁共振平扫或单做动态对比增强成像。结论 多单一做乳腺平扫或DCE检查都有一定的不足,多模态高场MRI乳腺扫描诊断乳腺良恶性病变的诊断效能较好,对乳腺恶性病变诊断的准确性较高,对乳腺良恶性病变的诊断具有较高的临床价值。

超低场磁共振膝关节正交接收线圈设计

射频接收线圈是磁共振成像(MRI)系统中的关键部件,用于检测变化的磁场,其性能直接影响图像的质量。超低场MRI射频接收线圈工作在较低频率,其阻抗特性不同于传统临床MRI射频接收线圈。理论上正交接收线圈比单通道线圈的信噪比(SNR)可以提高41%。而与阵列线圈相比,正交接收线圈可以用更低的成本与设计复杂度达到很好的成像效果。因此该文研究了一种用于超低场MRI(50.4 mT)系统的膝关节正交接收线圈,它由鞍形线圈和亥姆霍兹线圈组成。首先,确定了线圈的支撑结构及尺寸,并通过计算单匝接收线圈的效率及磁场的不均匀性来确定鞍形以及亥姆霍兹线圈的最优尺寸。然后,实测了线圈交流电阻,来评估线圈不同匝数的SNR,发现匝数增多会使得交流电阻显著增加,从而使SNR随着线圈匝数增加先增加后减少。最后,得到了两线圈的最佳匝数,并制作了正交接收线圈,从CuSO_(4)·5H_(2)O体膜以及体内膝关节成像来评估正交接收线圈的性能。在体膜和体内膝关节成像中,正交接收线圈与单通道线圈相比,图像SNR分别最大程度地提升了约33.5%和30.9%。

DCE-MRI定量参数联合小视野弥散加权成像对甲状腺良恶性结节鉴别的价值

目的探讨动态对比增强磁共振成像(dynamic contrast-enhanced magnetic resonance imaging,DCE-MRI)定量参数联合小视野弥散加权成像在甲状腺良恶性结节鉴别中的应用价值。材料与方法收集2022年1月至2023年10月于滨州医学院附属医院诊治并经手术病理证实为甲状腺结节的患者38例(52个结节),将其分为良性结节组和恶性结节组。术前患者均行3.0 T MRI扫描,包括常规MRI、小视野弥散加权成像(b值取0、800 s/mm^(2))和DCE-MRI检查,并测量其表观弥散系数(apparent diffusion coefficient,ADC)值和DCE-MRI定量参数,包括对比剂容积转运常数(volume transport constant,K^(trans))、速率常数(rate constant,K_(ep))、血管外细胞外间隙容积分数(extravascular extracellular volume fraction,V_(e))。对甲状腺良恶性结节组的ADC、K_(ep)、V_(e)、K^(trans)采用独立样本t检验分析,以P<0.05为差异有统计学意义,后将差异有统计学意义的变量进行逐步logistic回归模型分析,得到甲状腺良恶性结节的独立预测因素,并绘制受试者工作特征(receiver operating characteristic,ROC)曲线分析ADC、K^(trans)独立诊断模型及ADC与K^(trans)联合诊断模型的诊断效能。结果良性结节组平均ADC值、K^(trans)值、K_(ep)值分别为(1.659±0.370)×10^(-3)mm^(2)/s、(0.427±0.214)min^(-1)、(0.966±0.225)min^(-1),恶性结节组平均ADC值、K^(trans)值、K_(ep)值分别为(1.182±0.195)×10^(-3)mm^(2)/s、(0.178±0.073)min^(-1)、(0.600±0.248)min^(-1)。良性结节组的ADC、K^(trans)、K_(ep)值均高于恶性结节组,差异均有统计学意义(P<0.001)。经过独立样本t检验及逐步logistic回归分析显示,ADC值和K^(trans)差异具有统计学意义(P<0.05),是鉴别甲状腺结节良恶性的独立预测因子。单独ADC值曲线下面积(area under the curve,AUC)为0.915、单独K^(trans)值AUC为0.827。ADC值与K^(trans)联合诊断模型AUC为0.973,较二者单独应用明显增高,联合诊断模型诊断效能最高。经DeLong检验,联合诊断模型与单独K^(trans)诊断差异存在统计学意义(P<0.05)。ADC值与K^(trans)联合诊断模型在鉴别甲状腺良恶性结节中敏感度为97.3%,较ADC、K^(trans)更高,特异度为84.6%,较ADC值更高。结论ADC值和K^(trans)是鉴别甲状腺良恶性结节的重要参数,两者联合诊断可提高临床诊断准确性,为术前诊断提供重要依据。