Patient’s Comfort and Technical Quality Exams at 1.5 and 3.0 T Magnetic Resonance Imaging

Increased interest of clinicians for using 3.0 T magnetic resonance imaging (MRI), as imaging modality of choice for their patients, has been evident in the past few years. The aim of this study was to compare the technical quality of the obtained tomography using 3.0 T and 1.5 T MRI, and to compare the subjective feeling of discomfort of patients and subjective acoustic noise experience during imaging using MRI at 3.0 T and 1.5 T. Brain MRI (1.5 and 3.0 T) was performed in 58 patients, according to a standardized protocol. All studies have been randomly described by independent two radiologists. The reference standard for the existence of technical artifact is established on the basis of both radiologists’ consensus. We also compared the subjective feelings of the discomfort and acoustic noise during the both MRI (1.5 T and 3.0 T) exams. Artifacts were significantly more common during 3.0 T MRI in comparison with the 1.5 T MRI (χ2 = 5.286, P < 0.05), as well as in male patients (χ2 = 8.841, P < 0.05), and sub-jective assessments of discomfort and acoustic noise were higher in patients who underwent imaging using 3.0 T MRI, (χ2 = 125.959, df = 1, P < 0.001) and in females (χ2 = 195.449, df = 1, P < 0.001). Additional research is needed to prove that appropriate information for patients about the discomfort during 3.0 T MRI and their psychological preparation is very important element for optimal use of 3.0 T MRI in daily clinical practice.

Optimal b value of diffusion-weighted imaging on a 3.0T magnetic resonance scanner in Crohn's disease

AIM: To determine the optimal b value of diffusion-weighted imaging for detecting active inflammation in Crohn&#x02019;s disease.

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.

飞利浦Ingenia 3.0 T磁共振成像仪射频系统故障三例

磁共振成像无电离辐射且软组织成像效果较好,已成为常规体检和疾病诊断非常重要的医学影像诊疗技术之一。磁共振设备结构复杂,维修及维护成本较高,长期高负荷的运转会导致磁共振设备故障率增加。本文总结了本院飞利浦Ingenia 3.0 T磁共振设备射频系统故障三例,包括de-tuned印刷电路板故障、射频放大器故障及体线圈故障。文中对三例飞利浦磁共振设备射频系统故障的表现进行了描述,对故障产生的原因进行了分析并介绍了故障排除过程,包括观察外观、提取后台日志参数、测量疑似受损部件指标、更换受损部件以及系统测试。通过深入分析射频系统故障案例,分享维修经验,以期提高设备使用率。

3.0T磁共振成像联合多层螺旋电子计算机断层扫描对肛瘘临床分型的诊断价值

目的探讨3.0 T磁共振成像(MRI)联合多层螺旋电子计算机断层扫描(MSCT)对肛瘘临床分型的诊断价值。方法回顾性分析2020年1月至2022年5月在石家庄市中医院经手术证实的126例肛瘘病人临床资料,术前均行3.0 T MRI和MSCT检查。根据Parks分类法对比3.0 T MRI和MSCT对肛瘘病人检查的准确率,分析两项联合对肛瘘临床分型的诊断价值。结果3.0 T MRI联合MSCT诊断肛瘘外口的准确率(99.03%)高于MSCT单独诊断(90.29%),联合诊断主瘘管的准确率(100.00%)高于3.0 T MRI、MSCT各自单独诊断(93.65%、91.27%)(P<0.01),联合诊断肛瘘内口、瘘管分支、脓肿与各自单独诊断比较均差异无统计学意义(P>0.05);3.0 T MRI联合MSCT诊断括约肌间型、经括约肌型、括约肌上型、括约肌外型与手术结果的符合率分别为98.48%、100.00%、100.00%、100.00%。结论3.0 T MRI联合MSCT对肛瘘临床分型有良好的诊断价值。

3.0 T磁共振成像及CT在老年低位腰椎间盘突出诊断价值中的对比分析

目的:对比分析3.0 T磁共振成像及CT在老年低位腰椎间盘突出中的诊断价值。方法:选取2021年5月至2023年3月于我院就诊的63例疑似低位腰椎间盘突出患者,以临床最终诊断为金标准,所有患者均行3.0 T磁共振成像及CT检查,观察对比两种检查方式的诊断结果、诊断效能及低位腰椎间盘突出相关影像结果,并对两种检查方式的骨性结果参数进行比较。结果:3.0T磁共振成像的椎间盘变性、脊髓变性、硬膜囊受压检出率高于CT检查(P<0.05),CT的钙化、积气检出率高于3.0 T磁共振成像(P<0.05);3.0 T磁共振成像关节突关节角、腰骶角均高于CT,腰椎曲度、L5S_(1)椎间盘高度低于CT(P<0.05);3.0 T磁共振成像的诊断灵敏度、准确值均高于CT检查,漏诊率低于CT;3.0 T磁共振成像诊断不同类型低位腰椎间盘突出与术后结果的一致性Kappa值高于CT。结论:3.0 T磁共振成像在诊断椎间盘变性、脊髓变性、硬膜囊受压、神经走向中具有明显优势,在诊断钙化、积气中CT检出率更高,因此临床可根据具体情况结合两种检查方式的优点对腰椎间盘突出症进行诊断。

Magnetic Resonance Imaging and Histopathological Analysis of Experimental Muscle Injuries in a Rabbit

Objective To investigate the correlation of magnetic resonance imaging （MRI） with histopathologica changes, and to evaluate T2 mapping in assessing muscle trauma in a rabbit model of muscle injury. Methods We divided 35 rabbits into seven groups that each represented a different time point after intramuscular hemorrhage and muscle injury. Hemorrhage was created by injecting autologous blood into the left legs, and muscle injury was created by scalpel incision of the biceps femoris of the right legs. At different time points, the rabbits underwent Tl-weighted imaging and T2-weighted imaging （TzWl and T2Wl） and T2 mapping. T2 relaxation times were measured, and the corresponding samples were evaluated for pathological changes. Results After 2 h, the intramuscular hemorrhage model demonstrated an increased signal intensity on both TlWl and T2Wl. Histological examination showed erythrocytes within the muscle bundle. On days 1 and 3, the MRI signals were decreased, and there were no significant changes after day 7. From 2 h to 3 days, the muscle-injury model showed a high signal on both TzWl and T2Wl. Corresponding pathological changes included rupture and edema of muscle fibers, and inflammation. The abnormal signals were reduced on day 7. After day 14, the T2Wl intensity remained high. TlWl showed no abnormal changes, but some models showed a high signal, representing fresh bleeding and fatty tissue. T2 relaxation times were significantly different between the central and marginal regions, and between the marginal and normal regions. Conclusion MRI clearly demonstrates intramuscular hemorrhage and muscle injury, which correlate well with histopathological changes. Tz mapping is useful in assessing the extent of injury.

T2* magnetic resonance imaging of the liver in thalassemic patients in Iran

AIM: To investigate the accuracy of T2*-weighted magnetic resonance imaging (MRI T2*) in the evaluation of iron overload in beta-thalassemia major patients. METHODS: In this cross-sectional study, 210 patients with beta-thalassemia major having regular blood transfusions were consecutively enrolled. Serum ferritin levels were measured, and all patients underwent MRI T2* of the liver. Liver biopsy was performed in 53 patients at an interval of no longer than 3 mo after the MRIT2* in each patient. The amount of iron was assessed in both MRI T2* and liver biopsy specimens of each patient. RESULTS: Patients’ ages ranged from 8 to 54 years with a mean of 24.59 ± 8.5 years. Mean serum ferritin level was 1906 ± 1644 ng/mL. Liver biopsy showed a moderate negative correlation with liver MRI T2* (r = -0.573, P = 0.000) and a low positive correlation with ferritin level (r = 0.350, P = 0.001). Serum ferritin levels showed a moderate negative correlation with liver MRI T2* values (r = -0.586, P = 0.000). CONCLUSION: Our study suggests that MRI T2* is a non-invasive, safe and reliable method for detecting iron load in patients with iron overload.

Quantitative multiparametric magnetic resonance imaging can aid non-alcoholic steatohepatitis diagnosis in a Japanese cohort

BACKGROUND Non-invasive assessment of non-alcoholic steatohepatitis(NASH)is increasing in desirability due to the invasive nature and costs associated with the current form of assessment;liver biopsy.Quantitative multiparametric magnetic resonance imaging(mpMRI)to measure liver fat(proton density fat fraction)and fibroinflammatory disease[iron-corrected T1(cT1)],as well as elastography techniques[vibration-controlled transient elastography(VCTE)liver stiffness measure],magnetic resonance elastography(MRE)and 2D Shear-Wave elastography(SWE)to measure stiffness and fat(controlled attenuated parameter,CAP)are emerging alternatives which could be utilised as safe surrogates to liver biopsy.AIM To evaluate the agreement of non-invasive imaging modalities with liver biopsy,and their subsequent diagnostic accuracy for identifying NASH patients.METHODS From January 2019 to February 2020,Japanese patients suspected of NASH were recruited onto a prospective,observational study and were screened using noninvasive imaging techniques;mpMRI with LiverMultiScan®,VCTE,MRE and 2DSWE.Patients were subsequently biopsied,and samples were scored by three independent pathologists.The diagnostic performances of the non-invasive imaging modalities were assessed using area under receiver operating characteristic curve(AUC)with the median of the histology scores as the gold standard diagnoses.Concordance between all three independent pathologists was further explored using Krippendorff’s alpha(a)from weighted kappa statistics.RESULTS N=145 patients with mean age of 60(SD:13 years.),39%females,and 40%with body mass index≥30 kg/m2 were included in the analysis.For identifying patients with NASH,MR liver fat and cT1 were the strongest performing individual measures(AUC:0.80 and 0.75 respectively),and the mpMRI metrics combined(cT1 and MR liver fat)were the overall best non-invasive test(AUC:0.83).For identifying fibrosis≥1,MRE performed best(AUC:0.97),compared to VCTE-liver stiffness measure(AUC:0.94)and 2D-SWE(AUC:0.94).For assessment of steatosis≥1,MR liver fat was the best performing non-invasive test(AUC:0.92),compared to controlled attenuated parameter(AUC:0.75).Assessment of the agreement between pathologists showed that concordance was best for steatosis(a=0.58),moderate for ballooning(a=0.40)and fibrosis(a=0.40),and worst for lobular inflammation(a=0.11).CONCLUSION Quantitative mpMRI is an effective alternative to liver biopsy for diagnosing NASH and non-alcoholic fatty liver,and thus may offer clinical utility in patient management.

A multiple-tissue-specific magnetic resonance imaging model for diagnosing Parkinson’s disease: a brain radiomics study

Brain radiomics can reflect the characteristics of brain pathophysiology.However,the value of T1-weighted images,quantitative susceptibility mapping,and R2*mapping in the diagnosis of Parkinson’s disease(PD)was underestimated in previous studies.In this prospective study to establish a model for PD diagnosis based on brain imaging information,we collected high-resolution T1-weighted images,R2*mapping,and quantitative susceptibility imaging data from 171 patients with PD and 179 healthy controls recruited from August 2014 to August 2019.According to the inclusion time,123 PD patients and 121 healthy controls were assigned to train the diagnostic model,while the remaining 106 subjects were assigned to the external validation dataset.We extracted 1408 radiomics features,and then used data-driven feature selection to identify informative features that were significant for discriminating patients with PD from normal controls on the training dataset.The informative features so identified were then used to construct a diagnostic model for PD.The constructed model contained 36 informative radiomics features,mainly representing abnormal subcortical iron distribution(especially in the substantia nigra),structural disorganization(e.g.,in the inferior temporal,paracentral,precuneus,insula,and precentral gyri),and texture misalignment in the subcortical nuclei(e.g.,caudate,globus pallidus,and thalamus).The predictive accuracy of the established model was 81.1±8.0%in the training dataset.On the external validation dataset,the established model showed predictive accuracy of 78.5±2.1%.In the tests of identifying early and drug-naïve PD patients from healthy controls,the accuracies of the model constructed on the same 36 informative features were 80.3±7.1%and 79.1±6.5%,respectively,while the accuracies were 80.4±6.3%and 82.9±5.8%for diagnosing middle-to-late PD and those receiving drug management,respectively.The accuracies for predicting tremor-dominant and non-tremor-dominant PD were 79.8±6.9%and 79.1±6.5%,respectively.In conclusion,the multiple-tissue-specific brain radiomics model constructed from magnetic resonance imaging has the ability to discriminate PD and exhibits the advantages for improving PD diagnosis.

A decomposition method of nuclear magnetic resonance T2 spectrum for identifying fluid properties

Based on analysis of NMR T2 spectral characteristics,a new method for identifying fluid properties by decomposing T2 spectrum through signal analysis has been proposed.Because T2 spectrum satisfies lognormal distribution on transverse relaxation time axis,the T2 spectrum can be decomposed into 2 to 5 independent component spectra by fitting the T2 spectrum with Gauss functions.By analyzing the free relaxation response characteristics of crude oil and formation water,the dynamic response characteristics of the core mutual drive between oil and water,the petrophysical significance of each component spectrum is clarified.T2 spectrum can be decomposed into clay bound water component spectrum,capillary bound fluid component spectrum,micropores fluid component spectrum and macropores fluid component spectrum.According to the nature of crude oil in the target area,the distribution range of T2 component spectral peaks of oil-bearing reservoir is 165-500 ms on T2 time axis.This range can be used to accurately identify fluid properties.This method has high adaptability in identifying complex oil and water layers in low porosity and permeability reservoirs.

Cutting edge clinical applications in cardiovascular magnetic resonance

Today, the use of cardiovascular magnetic resonance(CMR) is widespread in clinical practice. The increased need to evaluate of subtle myocardial changes, coronary artery anatomy, and hemodynamic assessment has prompted the development of novel CMR techniques including T1 and T2 mapping, non-contrast angiography and four dimensional(4D) flow. T1 mapping is suitable for diagnosing pathologies affecting extracellular volume such as myocarditis, diffuse myocardial fibrosis and amyloidosis, and is a promising diagnostic tool for patients with iron overload and Fabry disease. T2 mapping is useful in depicting acute myocardial edema and estimating the amount of salvageable myocardium following an ischemic event. Novel angiography techniques, such as the selfnavigated whole-heart or the quiescent-interval singleshot sequence, enable the visualization of the great vessels and coronary artery anatomy without the use of contrast material. The 4D flow technique overcomes the limitations of standard phase-contrast imaging and allows for the assessment of cardiovascular hemodynamics in the great arteries and flow patterns in the cardiac chambers. In conclusion, the future of CMR is heading toward a more reliable quantitative assessment of the myocardium, an improved non-contrast visualization of the coronary artery anatomy, and a more accurate evaluation of the cardiac hemodynamics.

Three-dimensional time-of-flight magnetic resonance angiography combined with high resolution T2-weighted imaging in preoperative evaluation of microvascular decompression

BACKGROUND Neurovascular compression(NVC) is the main cause of primary trigeminal neuralgia(TN) and hemifacial spasm(HFS). Microvascular decompression(MVD) is an effective surgical method for the treatment of TN and HFS caused by NVC. The judgement of NVC is a critical step in the preoperative evaluation of MVD, which is related to the effect of MVD treatment. Magnetic resonance imaging(MRI) technology has been used to detect NVC prior to MVD for several years. Among many MRI sequences, three-dimensional time-of-flight magnetic resonance angiography(3D TOF MRA) is the most widely used. However, 3D TOF MRA has some shortcomings in detecting NVC. Therefore, 3D TOF MRA combined with high resolution T2-weighted imaging(HR T2WI) is considered to be a more effective method to detect NVC.AIM To determine the value of 3D TOF MRA combined with HR T2WI in the judgment of NVC, and thus to assess its value in the preoperative evaluation of MVD.METHODS Related studies published from inception to September 2022 based on PubMed, Embase, Web of Science, and the Cochrane Library were retrieved. Studies that investigated 3D TOF MRA combined with HR T2WI to judge NVC in patients with TN or HFS were included according to the inclusion criteria. Studies without complete data or not relevant to the research topics were excluded. The Quality Assessment of Diagnostic Accuracy Studies checklist was used to assess the quality of included studies. The publication bias of the included literature was examined by Deeks’ test. An exact binomial rendition of the bivariate mixed-effects regression model was used to synthesize data. Data analysis was performed using the MIDAS module of statistical software Stata 16.0. Two independent investigators extracted patient and study characteristics, and discrepancies were resolved by consensus. Individual and pooled sensitivities and specificities were calculated. The I_(2) statistic and Q test were used to test heterogeneity. The study was registered on the website of PROSERO(registration No. CRD42022357158).RESULTS Our search identified 595 articles, of which 12(including 855 patients) fulfilled the inclusion criteria. Bivariate analysis showed that the pooled sensitivity and specificity of 3D TOF MRA combined with HR T2WI for detecting NVC were 0.96 [95% confidence interval(CI): 0.92-0.98] and 0.92(95%CI: 0.74-0.98), respectively. The pooled positive likelihood ratio was 12.4(95%CI: 3.2-47.8), pooled negative likelihood ratio was 0.04(95%CI: 0.02-0.09), and pooled diagnostic odds ratio was 283(95%CI: 50-1620). The area under the receiver operating characteristic curve was 0.98(95%CI: 0.97-0.99). The studies showed no substantial heterogeneity(I2 = 0, Q = 0.001 P = 0.50).CONCLUSION Our results suggest that 3D TOF MRA combined with HR T2WI has excellent sensitivity and specificity for judging NVC in patients with TN or HFS. This method can be used as an effective tool for preoperative evaluation of MVD.

3.0 T盆腔MRI联合增强CT成像在结直肠肿瘤鉴别诊断中的应用价值

目的 探讨3.0 T盆腔磁共振(MRI)联合增强CT成像在结直肠肿瘤诊断中的应用价值,以期为临床制定干预措施提供依据。方法 回顾性分析焦作市人民医院2022年4月至2023年8月收治的138例结直肠肿瘤患者的资料,患者入院后均接受3.0 T盆腔MRI及增强CT成像检查,以病理检查结果为“金标准”,比较3.0 T盆腔MRI、增强CT成像对结直肠肿瘤单独、联合诊断结果、诊断效能,分析其对结直肠肿瘤临床分期诊断结果与病理检查结果一致性。结果 经病理检查结果显示,138例结直肠肿瘤患者中,阳性72例,经3.0 T盆腔MRI检查结果显示,阳性60例,经增强CT成像结果显示,阳性58例,经联合诊断结果显示,阳性71例;3.0 T盆腔MRI、增强CT成像联合检查对结直肠肿瘤诊断灵敏度为94.44%、准确度为94.93%,高于单独3.0 T盆腔MRI(灵敏度80.56%、准确度88.41%)及增强CT成像(灵敏度76.39%、准确度85.51%),漏诊率为5.56%,低于单独3.0 T盆腔MRI漏诊率(19.44%)及增强CT成像漏诊率(23.61%)(P<0.05);3.0 T盆腔MRI、增强CT成像及联合诊断结直肠肿瘤临床分期与病理结果一致性Kappa值分别为0.818、0.772、0.923(P<0.05)。结论 3.0 T盆腔MRI联合增强CT成像可用于结直肠肿瘤诊断中,为临床早期鉴别诊断、评估临床分期提供方案,以制定后续治疗措施,改善预后。

Linear-fitting-based similarity coefficient map for tissue dissimilarity analysis in T2^＊-w magnetic resonance imaging

Similarity coefficient mapping（SCM） aims to improve the morphological evaluation of T＊2weighted magnetic resonance imaging（T＊2-w MRI）. However, how to interpret the generated SCM map is still pending. Moreover, is it probable to extract tissue dissimilarity messages based on the theory behind SCM？ The primary purpose of this paper is to address these two questions. First, the theory of SCM was interpreted from the perspective of linear fitting. Then, a term was embedded for tissue dissimilarity information. Finally, our method was validated with sixteen human brain image series from multiecho T＊2-w MRI. Generated maps were investigated from signal-to-noise ratio（SNR） and perceived visual quality, and then interpreted from intra- and inter-tissue intensity. Experimental results show that both perceptibility of anatomical structures and tissue contrast are improved. More importantly, tissue similarity or dissimilarity can be quantified and cross-validated from pixel intensity analysis. This method benefits image enhancement, tissue classification, malformation detection and morphological evaluation.

Feasibility of imaging superficial palmar arch using microultrasound,7T and 3T magnetic resonance imaging

AIM To demonstrate feasibility of vessel wall imaging of the superficial palmar arch using high frequency microultrasound, 7T and 3T magnetic resonance imaging(MRI).METHODS Four subjects(ages 22-50 years) were scanned on a micro-ultrasound system with a 45-MHz transducer(Vevo 2100, Visual Sonics). Subjects' hands were then imaged on a 3T clinical MR scanner(Siemens Biograph MMR) using an 8-channel special purpose phased array carotid coil. Lastly, subjects' hands were imaged on a 7T clinical MR scanner(Siemens Magnetom 7T Whole Body Scanner) using a custom built 8-channel transmit receive carotid coil. All three imaging modalities were subjectively analyzed for image quality and visualization of the vessel wall. RESULTS Results of this very preliminary study indicated that vessel wall imaging of the superficial palmar arch was feasible with a whole body 7T and 3T MRI in comparison with micro-ultrasound. Subjective analysis of image quality(1-5 scale, 1: poorest, 5: best) from B mode, ultrasound, 3T SPACE MRI and 7T SPACE MRI indicated that the image quality obtained at 7T was superior to both 3T MRI and micro-ultrasound. The 3D SPACE sequence at both 7T and 3T MRI with isotropic voxels allowed for multi-planarreformatting of images and allowed for less operator dependent results as compared to high frequency microultrasound imaging. Although quantitative analysis revealed that there was no significant difference between the three methods, the 7T Tesla trended to have better visibility of the vessel and its wall. CONCLUSION Imaging of smaller arteries at the 7T is feasible for evaluating atherosclerosis burden and may be of clinical relevance in multiple diseases.

The Diagnostic Value of Brain Magnetic Resonance Imaging in Detecting CNS Diseases Among Advanced AIDS Patients

Objective To investigate the diagnostic value of brain magnetic resonance imaging in detecting central nervous system diseases among AIDS patients of different levels of T cells. Methods Total of 164 AIDS patients who did not receive antiviral treatment were divided into 2 groups according to their baseline CD4+ T cell counts. Group A had CD4+ T cell below or equal to 50 cells/μl(n = 81) and group B had CD4+ T cells over 50 cells/μl(n = 83). All patients underwent brain MRI scan. Imaging analysis and the prevalence of the central nervous system disorders were compared between two groups. Results Among them 48 cases were found of abnormal brain MRI, group A was higher than group B(35.8% vs. 22.9%) although without statistical significance(P = 0.065). Altogether 48 cases were diagnosed as AIDS related central nervous system disorders based on clinical symptoms, signs and laboratory findings. The prevalence of CNS disorders was higher in group A than in group B(41.9% vs. 16.8%) with statistical significance(P < 0.01). Conclusions The patients with CD4+ T cell count less than or equal to 50 cells/μl had high prevalence of CNS diseases. Brain MRI plays an important role in the diagnosis and differentiation of CNS diseases in advanced AIDS patients. This study suggests patients with low CD4+ T cell count(≤ 50/μl) should routinely undergo MRI examination.

3.0 T MRI动态增强与64层螺旋CT多期扫描诊断肝硬化背景下小肝癌的价值比较

目的比较3.0 T磁共振(MRI)动态增强与64层螺旋CT(64-MDCT)多期扫描对肝硬化背景下小肝癌的诊断价值。方法选择肝硬化合并小肝癌患者55例(66个癌性小结节),分别进行3.0 T MRI动态增强与64-MDCT多期扫描,由两位专家对检查结果进行判定,比较两种检查方法的诊断价值。结果两位观察者通过3.0 T MRI动态增强得到的ROC曲线下面积(AUC)分别为0.893±0.013、0.859±0.027,通过64-MDCT得到的AUC分别为0.657±0.034、0.679±0.026;两位观察者对两种检查方法的诊断价值比较,P均<0.01。两位观察者采用3.0T MRI动态增强诊断肝硬化背景下小肝癌的敏感度、特异度、阴性预测值均高于64-MDCT,P均<0.01。结论 3.0T MRI动态增强对肝硬化背景下小肝癌的诊断价值高于64-MDCT。

肝硬化结节及小肝癌患者3.0T MRI检查结果分析

目的评价3.0 T MRI检查在肝硬化再生性结节(RN)、异型增生性结节(DN)和小肝癌(SHCC)诊断和鉴别诊断中价值。方法回顾性分析经病理检查确诊的69例RN、DN及SHCC患者的3.0 T MRI平扫及容积采集技术(LAVA)三期动态增强扫描特点。结果 RN主要表现为T2WI低信号,动态增强方式呈"缓慢上升型";DN主要表现为T2WI高、低信号,信号较均匀结节的动态方式以"速升缓降型"为主,可有"结中结"(特征表现);SHCC主要表现为T1WI低信号、T2WI高信号,动态增强方式为"速升速降型"。结论肝硬化结节及小肝癌在3.0 T MRI上各有较为典型的表现,临床可据此进行诊断与鉴别诊断;对其他强化类型的肝脏病灶应结合肿瘤血管的扭曲增粗及包膜等表现排除SHCC。

3.0 T HR-MRI评估椎-基底动脉粥样硬化斑块在TIA病情发展中的价值

目的分析3.0 T高分辨率磁共振成像(3.0 T HR-MRI)评估椎-基底动脉粥样硬化斑块稳定性在短暂性脑缺血发作(TIA)的应用价值。方法选取2015年2月至2018年2月期间于本院诊治的TIA患者80例,所有患者均行3.0 T HR-MRI检查出椎-基底动脉粥样硬化斑块,记录椎-基底动脉粥样硬化斑块分布和厚度,并根据斑块稳定性将患者分为斑块稳定组(n=38)和斑块不稳定组(n=42),比较两组患者TIA发作次数以及发作持续时间,门诊随访1年,比较两组患者脑梗死或TIA再发时间、TIA再发次数及脑梗死例数。结果椎-基底动脉粥样硬化斑块最容易在背侧壁形成,斑块厚度以0.5~1.5mm为主;斑块不稳定组患者TIA发作次数显著多于斑块稳定组患者(P<0.05),TIA发作持续时间显著长于斑块稳定组患者(P<0.05);随访1年发现,斑块不稳定组患者脑梗死或TIA再次发作时间显著短于斑块稳定组患者(P<0.05),TIA发作次数、脑梗死例数高于斑块稳定组患者(P<0.05)。结论3.0 T HR-MRI能够评估椎-基底动脉粥样硬化斑块分布、厚度等情况,并对斑块进行定性分析,进一步预测TIA病情发展,为脑血管病二级预防提供更多依据。