Magnetic resonance imaging in breast cancer:A literature review and future perspectives

Early detection and diagnosis of breast cancer are essential for successful treatment. Currently mammography and ultrasound are the basic imaging techniques for the detection and localization of breast tumors. The low sensitivity and specificity of these imaging tools resulted in a demand for new imaging modalities and breast magnetic resonance imaging(MRI) has become increasingly important in the detection and delineation of breast cancer in daily practice. However, the clinical benefits of the use of pre-operative MRI in women with newly diagnosed breast cancer is still a matter of debate. The main additional diagnostic value of MRI relies on specific situations such as detecting multifocal, multicentric or contralateral disease unrecognized on conventional assessment(particularly in patients diagnosed with invasive lobular carcinoma), assessing the response to neoadjuvant chemotherapy, detection of cancer in dense breast tissue, recognition of an occult primary breast cancer in patients presenting with cancer metastasis in axillary lymph nodes, among others. Nevertheless, the development of new MRI technolo-gies such as diffusion-weighted imaging, proton spectroscopy and higher field strength 7.0 T imaging offer a new perspective in providing additional information in breast abnormalities. We conducted an expert literature review on the value of breast MRI in diagnosing and staging breast cancer, as well as the future potentials of new MRI technologies.

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.

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.

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.

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.

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.

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.

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.

AD小鼠脑胶质淋巴系统CSF流入量与年龄的关系:基于9.4 T DCE-MRI的可视化研究

目的基于9.4 T动态对比增强(dynamic contrast-enhanced,DCE)-MRI探索不同月龄的阿尔茨海默病(Alzheimer's disease,AD)模型小鼠脑胶质淋巴系统的脑脊液(cerebrospinal fluid,CSF)流入变化,以阐明随年龄增长脑胶质淋巴系统清除的变化规律及水通道蛋白4(aquaporin4,AQP4)在脑胶质淋巴系统清除中的作用。材料与方法取2、4、6和8月龄的APP/PS1 AD小鼠和野生型(wild-type,WT)小鼠,每组1只,共8组,向小脑延髓池中注射钆喷酸葡胺(Gadopentetate dimeglumine,Gd-DTPA)后第30 min完成第一次DCE-MRI扫描,以后每15 min采集一次,共完成8次扫描。随后在DCE-MRI扫描之前,使用AQP4抑制剂N-(1,3,4-噻二唑基)烟酰胺[N-(1,3,4-Thiadiazolyl)nicotinamide,TGN-020]对2月龄WT小鼠进行处理。采用免疫荧光法检测AQP4和β-淀粉样蛋白随月龄增长的表达变化。结果在APP/PS1小鼠模型的疾病早期,观察到随月龄增加,淀粉样蛋白逐渐累积,CSF流入信号强度均值从增加到降低,其中4至6月龄小鼠淀粉样蛋白的累积速率缓慢,对应于相应月龄CSF流入信号强度均值最高(4月龄为2711.67±1270.25;6月龄为2632.25±729.65)。同时,AQP4表现出随月龄增加极化程度降低的变化过程。随后,经AQP4抑制剂TGN-020处理后,观察到脑胶质淋巴系统的CSF流入信号强度均值降低(由3578.08±1199.95下降为1655.42±377.96;P=0.06)。结论在AD疾病的早期阶段(8月龄前),6月龄的脑胶质淋巴系统利用更明显,此阶段可能作为AD治疗的窗口期。AQP4在脑胶质淋巴系统中起着重要作用,可能作为研究和治疗AD的靶点。

体素内不相干运动-弥散加权成像评价不同栓塞材料经动脉化疗栓塞治疗肝细胞癌效果及预后

目的 探讨MR体素内不相干运动(IVIM)-弥散加权成像(DWI)评价经导管动脉化疗栓塞术(TACE)治疗肝细胞癌(HCC)效果及预后。方法 选取2019年6月30日至2022年12月30日山东第一医科大学第二附属医院和新疆医科大学第一附属医院采用TACE治疗的84例不能手术切除HCC患者临床资料。TACE术中根据患者病情使用不同栓塞材料,术前及术后1、6、12个月行IVIM-DWI检查。根据IVIM-DWI序列设定的固定b值,分析不同栓塞材料下单指数模型表观弥散系数(ADC)值和双指数模型纯弥散系数(D值)、伪弥散系数(D*值)和灌注分数(f值)。根据改良实体瘤疗效评价标准(mRECIST)及不同栓塞治疗材料将患者分为稳定组和进展组,对比分析ADC值、D值、D*及f值变化。采用多因素Cox回归分析年龄、肝功能Child-Pugh分级、甲胎蛋白(AFP)含量、肿瘤大小等4个临床参数和治疗前后ADC值、D值、D*值、f值共8个功能学定量指标参数,确定具有预后预测价值的IVIM参数。通过受试者工作特征曲线(ROC)分析IVIM参数对预测值的诊断价值和Cut-off值。结果 治疗后载药微球组ADC值显著高于碘化油组,载药微球组、碘化油组D*值显著低于PVA颗粒组,载药微球组f值显著低于碘化油组(均P<0.01)。稳定组中载药微球组疗效明显优于碘化油组和PVA颗粒组,进展组中碘化油组比载药微球组和PVA颗粒组更易出现疾病进展。稳定组治疗前f值显著高于进展组(P=0.005),治疗后ADC值显著高于进展组(P=0.029)。ROC分析显示,载药微球组、碘化油组、PVA颗粒组分别中位随访30、19、26个月,总平均生存时间为25个月,总生存时间差异有统计学意义(P<0.01)。多因素Cox回归分析显示,治疗前D值(AUC 0.878)、D*值(AUC 0.554)及治疗后D值(AUC 0.791)、D*值(AUC 0.552)、f值(AUC 0.467)是TACE近期疗效的独立影响因素(均P<0.05),治疗前后D值诊断效能更高,治疗前D值<0.505×10-3mm2/s、治疗后D值<0.785×10-3mm2/s时预测为疗效差。结论 治疗前后D值是预测不同栓塞材料TACE治疗HCC疗效的最佳参数。

不同节段直肠癌T分期的多模态1.5T MRI评估与病理对照研究

目的探讨分析多模态1.5T磁共振成像(MRI)对不同节段直肠癌T分期的评估价值。方法选取我院2018年6月至2023年3月收治的经肠镜下活检确诊的160例直肠癌患者作为研究对象,所有患者术前均进行多模态1.5T MRI检查,并接受全直肠系膜切除术(TME)治疗及术后病理分析,以病理结果为金指标,分析1.5T MRI对直肠癌T分期的评估价值;依据肠镜测量的肿瘤距肛门距离将全部患者分为低位直肠癌、中位直肠癌、高位直肠癌,分析多模态1.5T MRI检查对不同节段直肠癌T分期的评估价值及效能分析。结果1.5T MRI分期的评估准确率为89.38%;MRI T_(1)分期的准确率、敏感性、特异性、阳性预测值及阴性预测值分别为98.75%、94.74%、100.00%、100.00%、98.39%;T2分期的各项评估结果分别为91.25%、86.49%、92.68%、78.05%、95.80%;T3分期的各项评估结果分别为90.63%、75.61%、95.80%、86.11%、91.94%;T4分期的各项评估结果分别为100.00%、100.00%、97.48%、93.62%、100.00%;1.5T MRI低位及中位直肠癌T_(1)分期的准确率、特异性及阳性预测值最高,T4分期的敏感性及阴性预测值最高;高位直肠癌T_(1)分期的的评估准确率、敏感性、特异性及阴性预测值,T4分期的敏感性及阴性预测值最高;且三个阶段其他T分期的各项效能分析均较高。结论1.5T MRI评估效果显著,且对于直肠癌患者T分期的各项效能指标评估分析参考价值都较高,有更为准确的评估结果,值得临床上使用推广。

1.5 T MRI与64排多层螺旋CT在脊柱骨折临床诊断中的作用

目的探讨1.5 T磁共振成像(magnetic resonance imaging,MRI)与64排多层螺旋计算机体层成像(computed tomography,CT)对脊柱骨折的诊断价值。方法方便选取2021年1月—2022年12月泰兴市第二人民医院收治的82例疑似脊柱骨折患者作为研究对象,均予1.5 T MRI与64排多层螺旋CT检查,以手术结果为金标准,评估两种技术对脊柱骨折的诊断效能,并分析其对脊柱骨折分型的诊断价值。结果1.5 T MRI对脊柱骨折诊断的准确度、灵敏度与64排螺旋CT比较,差异无统计学意义(P均>0.05)。两种方法与金标准一致性均较好(kappa值≥0.75)。1.5 T MRI对脊柱骨折A、B、C型分型诊断整体符合率为97.56%,高于64排多层螺旋CT的86.59%,差异有统计学意义(χ^(2)=7.111,P<0.05)。结论1.5 T MRI与64排螺旋CT对脊柱骨折诊断效能相当,但1.5 T MRI的分型诊断效能更高。

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。

Manganese-doped mesoporous polydopamine nanoagent for T1-T2 magnetic resonance imaging and tumor therapy

Theranostic nanodrugs combining magnetic resonance imaging(MRI)and cancer therapy have attracted extensive interest in cancer diagnosis and treatment.Herein,a manganese(Mn)-doped mesoporous polydopamine(Mn-MPDA)nanodrug incorporating the nitric oxide(NO)prodrug BNN6 and immune agonist R848 was developed.The nanodrug responded to the H^(+)and glutathione being enriched in tumor microenvironment to release R848 and Mn^(2+).The abundant Mn^(2+)produced through a Fenton-like reaction enabled a highly sensitive T1-T2 dual-mode MRI for monitoring the tumor accumulation process of the nanodrug,based on which an MRI-guided laser irradiation was achieved to trigger the NO gas therapy.Meanwhile,R848 induced the re-polarization of tumor-promoting M2-like macrophage to a tumoricidal M1 phenotype.Consequently,a potent synergistic antitumor effect was realized in mice bearing subcutaneous 4T1 breast cancer,which manifested the great promise of this multifunctional nanoplatform in cancer treatment.

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。

Pancreatic imaging:Current status of clinical practices and small animal studies

Different causative factors acting on the pancreas can result in diseases such as pancreatitis, diabetes and pancreatic tumors. The high incidence and mortality of pancreatic diseases have placed diagnostic imaging in a crucial position in daily clinical practice. In this minireview article different pancreatic imaging techniques are discussed, from the standard clinical imaging modalities and state of the art clinical magnetic resonance imaging techniques to current situations in pre-clinical pancreatic imaging studies. In particular, the challenges of pre-clinical rodent pancreatic imaging are addressed, with both the image acquisition techniques and the post-processing methods for rodent pancreatic imaging elaborated.

Post-operative imaging in liver transplantation: State-of-the-art and future perspectives

Orthotopic liver transplantation(OLT)represents a major treatment for end-stage chronic liver disease,as well as selected cases of hepatocellular carcinoma and acute liver failure.The ever-increasing development of imaging modalities significantly contributed,over the last decades,to the management of recipients both in the pre-operative and post-operative period,thus impacting on graft and patients survival.When properly used,imaging modalities such as ultrasound,multidetector computed tomography,magnetic resonance imaging(MRI)and procedures of direct cholangiography are capable to provide rapid and reliable recognition and treatment of vascular and biliary complications occurring after OLT.Less defined is the role for imaging in assessing primary graft dysfunction(including rejection)or chronic allograft disease after OLT,e.g.,hepatitis C virus(HCV)recurrence.This paper:(1)describes specific characteristic of the above imaging modalities and the rationale for their use in clinical practice;(2)illustrates main imaging findings related to post-OLTcomplications in adult patients;and(3)reviews future perspectives emerging in the surveillance of recipients with HCV recurrence,with special emphasis on MRI.

MRI评估直肠癌不同T分期的价值分析

目的 分析MRI术前评估直肠癌不同T分期的价值。方法 以行直肠癌扩大根治术的患者为研究对象,患者术前均行MRI检查评估直肠癌的T分期,并行病理学检查确定其病理分期。通过诊断试验与受试者工作特征(ROC)曲线来分析MRI术前评估直肠癌不同分期的价值。结果 MRI术前评估直肠癌患者T分期的总体正确率为58.51%。其评估直肠癌T_(3)分期的价值可达中等,高于其评估T_(1)、T_(2)和T_(4)期的价值,而其评估T_(1)、T_(2)和T_(4)的价值均较低。MRI评估T_(3)分期的灵敏度较高,特异度和正确率尚可,假阴性率较低,阴性预测价值较高,但其假阳性率较高,阳性预测价值较低。结论 应用MRI评估直肠癌T分期时,应考虑到MRI术前评估直肠癌不同T分期的价值,以便做出更准确的分期诊断。

Impact of Field Strength and Respiratory Motion Control on Diffusion-Weighted MR Imaging of the Liver

Purpose: To evaluate the impact of field strength and respiratory motion control on diffusion-weighted MR imaging (DWI) of the liver at 1.5 and 3 T. Material and Methods: Three DWI sequences using seven b-values from 20 - 400 s/mm2 were designed with identical parameters but with different handling of respiratory motion [respiratory triggered (RT), free breathing (FB), breath hold (BH)] on 3 T and 1.5 T. Thirteen volunteers were examined at a 3 T and six of them also at a 1.5 T magnet. DW images were analyzed quantitatively and qualitatively. Regions of interest were placed in cranial, middle and caudal parts of the right liver lobe (RLL) and ADC and SNR were calculated. Results: ADC in RLL tended to be lower at 3 T MRI. Least inter-subject ADC variability was found with RT in the middle RLL at 3 T. Highest ADCs were found caudally in the RLL. Significant differences in ADC between middle and caudal RLL were calculated in FB and RT at 3 T and FB and BH at 1.5 T, respectively. No significant difference in SNR was found between 3 T and 1.5 T. There were significantly more artifacts in the left liver lobe (LLL) compared to the RLL in all sequences and in the LLL at 3 T compared to 1.5 T. Conclusion: Our study suggests that longitudinal hepatic ADC measurements should be performed using equivalent field strength, b-values, and acquisition technique, given influence of these factors on ADC measurements.

术前多模态MRI成像与MSCT评价胃癌T分期价值比较

目的研究术前多模态MRI成像与MSCT图像评价胃癌T分期价值。方法2017年1月至2019年12月于医院接受MRI成像与MSCT检查的胃癌患者术80例,根据检测方式分为对照组和实验组各40例;对照组采用MSCT检测;实验组采用MRI检测;分别对胃癌的术前T分期进评估,将检查结果与以手术组织学检测结果为“金标准”进行比较,比较两种方法的诊断效能。结果对照组对胃癌T_(1)期和T_(2)期诊断符合率分别为75.00%、88.98%与实验组诊断符合率77.78%、88.89%差异无统计学意义(P>0.05);实验组对胃癌T_(3)期和T_(4)期诊断符合率分别为81.81%、90.91%显著高于对照组45.45%、50.00%(P<0.05);两种方式对T_(1)期和T_(2)胃癌的诊断效能差异无统计学意义,MRI对胃癌T_(3)期和T_(4)期诊断效能显著高于MSCT。结论MRI成像与MSCT图像对于评价T_(1)期和T_(2)期胃癌无明显优势,但对于T_(3)期和T_(4)期MRI成像具有较大的优势。