Objective: To correlate the clinical RDC/TMD findings with Magnetic resonance imaging (MRI) as a diagnostic aid in the internal derangement of TMJ. Methods: The present study consists of a total sample size of 14 subjects clinically diagnosed with the internal derangement of TMJ. According to the set criteria by Research Diagnostic Criteria for Temporomandibular disorders (RDC/TMD), the subjects were subjected to MRI after a thorough evaluation. The diagnostic findings were compared with MRI. The data obtained were statistically analyzed using the specificity, sensitivity, and kappa coefficient. Results: Twenty-five percent of sensitivity and fifty-seven percent of specificity were observed for RDC/TMD diagnosis regarding MRI in the total sample. Kappa value was found to be in the moderate range. Conclusion: The clinical findings based on RDC/TMD alone were not sufficient for the diagnosis of TMJ, and MRI’s internal derangement still a “golden standard” among the other modalities.

Background Syphilitic vasculitis (SV) is rare and difficult to be diagnosed. High-resolution vessel wall magnetic resonance imaging (HR-VWI) might be valuable in the diagnosis by differentiating SV from other vessel wall pathologies. Methods We report a rare case with severe isolated middle cerebral artery (MCA) stenosis and cerebral infarction, which was evaluated by serial HR-VWI. Results A 46-year-old woman presented with an acute infarct in the left basal ganglia and severe isolated stenosis in left middle cerebral artery (MCA). Cerebrospinal fluid (CSF) analysis was performed and the findings were consistent with neurosyphilis diagnosis. The MCA stenosis was also suspected to be the result of SV. HR-VWI revealed the evidence of concentric thickening and circular uniform enhancement of the arterial wall. After two cycles of anti-syphilis treatment, subsequent HR-VWI showed that the MCA stenosis was reduced significantly except slight enhancement of the arterial wall, which confirmed that the SV caused the isolated MCA stenosis. Conclusions HR-VWI could be an important diagnostic tool for isolated middle cerebral artery stenosis caused by SV, which could serve as a biomarker for assessing the response to anti-syphilis treatment in the future.

Background: Evaluate the predictive value of myocardial stress measured by magnetic resonance imaging (MRI) on the severity of coronary artery stenosis and acute myocardial infarction (AMI). In the early stage of acute myocardial infarction, many imaging findings are negative, and MRI myocardial stress detection is controversial in the diagnosis of this aspect. Therefore, it is necessary to determine whether MRI myocardial stress can diagnose acute myocardial infarction. Methods: A total of 120 patients were divided into an AMI group and non-AMI group. The AMI group was further divided into a mild group, moderate group, and severe group. The myocardial stress was measured by MRI, compared in each group, the correlation between myocardial stress and coronary artery stenosis rate was analyzed, and coronary artery disease (CAD) compared between patients with AMI, and the relationship between myocardial stress and AMI was observed. Results: Among the 120 patients, there were 77 cases in the AMI group, including 21 cases in the mild group, 40 cases in the moderate group, and 16 cases in the severe group. There were a total of 43 cases in the non-AMI group. Myocardial stress in the AMI group was significantly higher than that in the non-AMI group (P<0.05). The myocardial stress increased gradually in the mild, moderate, and severe AMI groups (P<0.001). Myocardial stress was positively correlated with coronary artery stenosis rate (P<0.001) and CAD (P<0.05). Logistic regression analysis showed that myocardial stress was an independent risk factor for AMI (P<0.05). The sensitivity and specificity of myocardial stress >5.15 mm in the diagnosis of AMI were 83.5%, 68.6% (AUC =0.834), respectively. Acute myocardial infarction is often caused by risk factors such as hyperlipidemia, hypertension and hyperglycemia, as well as vascular stenosis caused by arterial wall malformation, vascular wall inflammation or vasospasm. Conclusions: The MRI measurement of myocardial stress is simple, reliable, and practical to evaluate the degree of coronary artery lesions. Myocardial stress is closely related to AMI and can assist in the diagnosis of AMI.

目的 定量评价基于延迟交变章动调整激发(delay alternating with nutation for tailored excitation,DANTE)预脉冲3D CUBE磁共振序列对动脉管壁成像与病理结果的一致性.材料与方法 采用高脂饲料喂养加腹主动脉内膜拉伤手术制作12只新西兰大白兔的动脉粥样硬化模型,同期普通饲料喂养8只作为对照组.运用3.0 T 磁共振扫描仪对腹主动脉行冠状位黑血DANTE预备的CUBE容积扫描,包括T1WI和T2WI序列,而后行病理HE染色及高清数字化扫描.对磁共振图像进行横轴位重建,测量磁共振和病理图像管腔面积(lumen area,LA)、血管总面积(total area,TA),计算管壁面积(wall area,WA),WA=TA-LA,以及计算标准化管壁指数(normalized wall index,NWI),NWI=WA/TA.T1WI和T2WI的NWI分别用NWIT1和NWIT2表示.根据病理图片勾画血管壁外膜内边缘和外膜外边缘,相应的NWI分别用NWIP1和NWIP2表示.比较影像和病理定量指标在实验组与对照组之间的差异,并采用组内相关系数(intraclass correlation coefficient,ICC)、Bland-Altman plots评估磁共振序列之间、磁共振与病理之间的NWI一致性.结果 最终19只兔(实验组1只磁共振成像检查前死亡)纳入统计.与对照组相比,实验组的LA明显较小(T1WI,P=0.033;T2WI,P＜0.0001)、NWI明显较大(T1WI,P＜0.0001;T2WI,P＜0.0001).整体一致性分析发现,NWIT1和NWIT2之间的一致性较好(ICC=0.7552),NWIT1或NWIT2与NWIP1的一致性次之(ICC=0.438;ICC=0.444),NWIT1或NWIT2与NWIP2的一致性最差(ICC=0.285;ICC=0.292).实验组的一致性分析与上述结果类似.对照组中,NWIT1和NWIT2之间的一致性也较好(ICC=0.6304),但NWIT1或NWIT2与NWIP1的一致性较差(ICC=-0.1917;ICC=-0.05949),NWIT1或NWIT2与NWIP2的一致性也较差(ICC=-0.1989;ICC=-0.1441).结论 3D DANTE CUBE的T1WI和T2WI可以量化区分兔腹主动脉粥样硬化病变管壁与正常管壁,且这两个常用加权序列之间的一致性较好.根据与病理的一致性分析,DANTE CUBE序列测量的NWI相对接近病理图像中血管外膜内边缘测量的结果,但总体而言一致性欠佳,在管壁菲薄的正常血管比较中尤甚.

Background: Circular RNAs (circRNAs) are involved in atherosclerosis (AS) development. However, the function and mechanism of circRNA hsa_circ_0003204 (circ_0003204) in carotid artery AS remain unclear. Methods: Oxidized low-density lipoprotein (ox-LDL)-treated human carotid artery endothelial cells (HCtAECs) and THP-1 cells were used as cell models of carotid artery AS. Relative levels of circ_0003204, microRNA-188-3p (miR-188-3p), and transient receptor potential canonical channel 6 (TRPC6) were detected by quantitative reverse transcription–polymerase chain reaction or Western blotting. The targeting relationship between circ_0003204 or TRPC6 and miR-188-3p was assessed via dual-luciferase reporter analysis and RNA immunoprecipitation. Cell proliferation was assessed via 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay and 5-ethynyl-2′-deoxyuridine (EdU) assay. Cell apoptosis was analyzed via assessing cell caspase-3 activity, apoptosis, and apoptosis-related protein. Inflammatory response was analyzed via analysis of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α). Oxidative stress was assessed via determination of reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD). Results: Circ_0003204 and TRPC6 levels were elevated, and miR-188-3p expression declined in ox-LDL-treated HCtAECs and THP-1 cells. Circ_0003204 could regulate TRPC6 expression via mediating miR-188-3p. Circ_0003204 silencing weakened ox-LDL-induced viability inhibition and apoptosis in HCtAECs, and inflammatory response and oxidative stress in THP-1 cells via regulating miR-188-3p. MiR-188-3p overexpression attenuated ox-LDL-induced injury in HCtAECs and THP-1 cells by targeting TRPC6. Conclusion: Circ_0003204 knockdown mitigated ox-LDL-induced injury in HCtAECs and THP-1 cells via regulating the miR-188-3p/TRPC6 axis, indicating that circ_0003204 might play an important role in carotid artery AS.

Purpose: To evaluate the apparent diffusion coefficient (ADC) test-retest repeatability of the normal pancreas based on diffusion-weighted imaging (DWI). Methods: Twenty-six healthy volunteers (mean 47.6 years; 13 men) were included and scanned twice with reposition for a DWI sequence at 3.0-T. Two readers measured the ADCs of pancreatic head, body and tail for two DWIs, independently. The mean ADCs of the pancreatic head, body and tail were calculated as the global pancreatic ADC. Test-retest repeatability and agreement of ADC measurement were evaluated by the Bland-Altman analysis, intra-class correlation coefficient (ICC) and coefficient of variation (CV). Results: The global pancreatic ADC showed the best test-retest repeatability (mean difference ± limits of agreement were 0.05 ± 0.25×10-3 mm2/s; ICC, 0.79; CV, 6%). Test-retest repeatabilities for ADC of pancreatic head, body or tail were scattered, with mean difference ± limits of agreement between two tests were 0.03 ± 0.47, 0.05 ± 0.42 and 0.06 ± 0.31 (×10-3 mm2/s) (ICCs, 0.81, 0.52 and 0.68; CVs, 9%, 8% and 8%), respectively. Both intra-observer repeatability and inter-observer reproducibility were acceptable for global pancreatic ADC between measurements of the two DWIs. Conclusions: The best test-retest repeatability of ADC in the normal pancreas was only for the whole pancreas with a CV of 6%. Cautions should be taken in interpreting longitudinal clinical changes in ADC values of the normal pancreas for the measurements do have an inherent variability by locations.

目的 利用新西兰大白兔腹主动脉动脉粥样硬化模型探讨基于DANTE预脉冲CUBE序列对管壁成像定量测量的可重复性.方法 采用高脂饲料喂养加腹主动脉内膜拉伤手术制作8只新西兰大白兔的动脉粥样硬化模型,同期普通饲料喂养2只作为对照组.运用3.0T MRI仪对兔的腹主动脉进行扫描,扫描序列包括常规2D横轴位FSE T2WI、FSE T1WI以定性观察管壁情况,3D冠状位黑血DANTE预备的CUBE T2WI和T1WI序列,以进行后续的定量评估.重复测量和计算腹主动脉的管腔面积(LA)、血管总面积(TA)及管壁面积(WA),统计变异系数(CV)和组内相关系数(ICC)以评估观察者间和观察者内的一致性.结果 最终8只兔完成MRI检查,横轴位2D序列中以脂肪抑制T2WI显示管壁轮廓较佳,冠状位3D DANTE CUBE的T1WI和T2WI序列均可清晰显示实验组腹主动脉管壁不同程度增厚.病理检查示,3只实验组的管壁为AHAⅡ型斑块,另3只为AHAⅠ型斑块.DANTE CUBE成像的观察者内的一致性较高:T1WI和T2WI序列的LA、TA和WA的CV均小于15％;ICC均大于0.4.观察者间一致性也较高:除了DANTE CUBE T2WI序列的LA的CV稍大于15％(15.86％)以外,其余CV均小于15％;ICC均大于0.4.结论 与2D磁共振管壁成像相比,DANTE黑血预备的3D CUBE序列扫描范围较大、时间效率较高,且空间分辨率可达到对动脉粥样硬化血管进行定量评估的要求.

目的:通过与数字减影血管造影(DSA)对比,探讨三维磁共振颅内血管壁成像(3D IVWI)诊断颅内动脉粥样硬化性狭窄的临床价值.方法:收集42例颅内动脉粥样硬化患者,在3D IVWI和DSA上分别测量管腔狭窄程度及斑块长度;并评价3D IVWI和DSA测量结果的一致性和相关性.结果:42例患者共检出102个颅内动脉粥样硬化斑块.Bland-Altman分析图显示2种检查手段测量管腔狭窄程度和斑块长度具有较好的一致性,组内相关系数(ICC)均大于0.77(分别为0.84和0.85).在测量管腔狭窄程度(r=0.69,P＜0.001)和斑块长度(r=0.84,P＜0.001)上,3D IVWI与DSA存在相关性.3D IVWI测量的斑块长度较DSA长(P＜0.001).结论:与DSA相比,3D IVWI对颅内动脉粥样硬化性狭窄诊断准确,重复性好,能检测到更多的斑块,在颅内动脉粥样硬化斑块检测、诊断及治疗中有较高的价值.

Background The progression of atherosclerotic plaque is a dynamic process; however, the natural evolution process of plaque enhancement on MRI remains unclear. Purpose To evaluate changes in enhancement characteristics of middle cerebral arterial (MCA) atherosclerotic plaques over time using MRI and to explore the relationship between the changes in plaque enhancement and stroke recurrence. Study Type Prospective. Population Fifty-four patients with MCA atherosclerotic plaque underwent initial and follow-up examinations with a median interval of 519 days (range 84-1820 days), including 37 males and 16 patients with recurrent stroke. Field Strength/Sequence Time-of-flight magnetic resonance angiography, diffusion-weighted imaging, T-2-weighted imaging, pre- and postcontrast T-1-weighted imaging at 3 T. Assessment Clinical characteristics and differences in the changes in plaque enhancement among acute, subacute and chronic stroke groups and the changes in the degree of stenosis and plaque enhancement between the patients with and without recurrent stroke were compared. Risk factors for patients with recurrent stroke were assessed. Intra- and interobserver agreement in initial and the changes in plaque enhancement and stenosis, and the correlation between changes in plaque enhancement and recurrent stroke, were evaluated. Statistical Tests Independent-samplest-test, Mann-WhitneyU-test, chi-squared test, Spearman correlation, logistic regression and Cohen's kappa test. Results There were significant differences in the changes in stenosis and plaque enhancement (P < 0.05) between the patients with and without recurrent stroke. A significant correlation was observed between the changes in plaque enhancement and stroke recurrence (r= 0.415,P < 0.05). Multivariate regression analysis showed that a change in plaque enhancement was an independent factor for stroke recurrence after adjusting for confounding factors (odds ratio [OR] = 5.797,P < 0.05). There was excellent intra- and interobserver agreement in evaluating plaque enhancement and stenosis. Data Conclusion Stable or increased enhancement of MCA plaque was related to recurrent stroke events at follow-up. Change in plaque enhancement on MRI may be an important indicator for predicting recurrent stroke. Level of Evidence 2 Technical Efficacy Stage 2

目的:利用3.0T磁共振3D DANTE-CUBE序列对动脉进行重复扫描及可重复性分析,评价该序列在动物动脉管壁成像中的稳定性和可靠性.方法:研究对象为8只新西兰大白兔,其中实验组(5只)行高脂饲料喂养加腹主动脉内膜拉伤术造模.运用3D DANTE CUBE的T1WI和T2WI序列对腹主动脉扫描,2周后重复扫描一次.“观察者1”测量两次扫描图像,以计算重复扫描的一致性;针对第二次扫描,“观察者1”前后测量2次、“观察者2”测量1次,以计算组内和组间的一致性.定量参数为管腔面积(AL)、血管总面积(AT)和管壁面积(Aw).最后对目标血管行病理检查.结果:最终6只兔(实验组3只)纳入统计,DANTE-CUBE的T1WI和T2WI序列均可清晰显示管壁病变和斑块成分,实验组的管壁面积显著大干对照组(P＜0.001).重复扫描的一致性T1WI的AL、T2WI的AL和Aw的一致性都非常好(IC C＞0.75,CV＜15％).观察者内的一致性:T1WI的所有参数的一致性都非常好(ICC＞0.75,CV＜15％);T2WI的AL和Aw的一致性非常好(ICC＞0.75,CV＜15％).观察者间的一致性分析:T1WI和T2WI的所有参数的一致性都非常好(ICC＞0.75,CV＜15％).结论:本研究3D DANTE-CUBE管壁成像序列可以精准且稳定地评价动物的动脉粥样硬化管壁,为进一步的临床应用奠定了技术基础.

The purpose of this study is to investigate the relationship between morphology, hemodynamics, and aneurysm wall enhancement (AWE) on vessel wall MRI and their potential role in rupture of intracranial aneurysms. Fifty-seven patients (22 males and 35 females; mean age of 58.4) harboring 65 unruptured intracranial aneurysms were retrospectively recruited. Vessel wall MRI images were reviewed and differentiated as no (NAWE), partial (PAWE), and circumferential (CAWE) wall enhancement. Computational geometry and computational fluid dynamics were used to calculate morphological and hemodynamic parameters. The PHASES score was calculated for each case to estimate its rupture risk. Univariate and multivariate logistic regression analysis was performed to investigate the relationship between morphological-hemodynamic pattern and AWE as well as their association with rupture risk. AWE was present in 26 (40.0%) lesions, including 14 (21.5%) PAWE and 12 (18.5%) CAWE. Aneurysm size (odds ratio = 7.46, 95% confidence interval = 1.56-35.77,p = 0.012), size ratio (odds ratio = 12.90, 95% confidence interval = 2.28-72.97,p = 0.004), and normalized wall shear stress (odds ratio = 0.11, 95% confidence interval = 0.02-0.69,p = 0.018) were independently associated with the presence of AWE. With increasing PHASES score, size-related parameters and the frequency of irregular shape increased significantly, and a hemodynamic pattern of lower and oscillating wall shear stress was observed. Simultaneously, the proportion of NAWE aneurysms decreased, and PAWE and CAWE aneurysms increased significantly (p < 0.001). Unruptured intracranial aneurysms with a higher rupture risk presented with a significantly larger size, lower wall shear stress, and more intense AWE, which might support the interaction between morphology, hemodynamics, and inflammation and their potential role in aneurysm rupture prediction.

目的 探索高分辨DCE-MRI技术对动脉粥样硬化兔的腹主动脉管壁评估的可重复性.方法 模型组(n=16)兔行高脂饲料喂养加腹主动脉球囊拉伤术造模,对照组(n=4)仅基础饲料喂养.MR检查方案包括3D延迟交替进动的定制激发技术(DANTE)CUBE序列和3D DCE-MRI序列,间隔1周后对模型组腹主动脉有病变者再次扫描,以计算重复扫描的一致性.2名医师分别测量1次,以计算组间一致性;1名医师前后测量2次,以计算组内一致性.需评估的DCE-MRI参数包括半定量的最大强化斜率(Max Slope)、钆对比剂浓度时间曲线下的初始面积(IAUGC)和强化率(CER),以及定量的体积转运常数(Ktrans)、血管外细胞外容积分数(Ve)和反向转运常数(Kep).最后,处死动物后对腹主动脉行病理HE染色.结果 最终模型组13只兔的腹主动脉形成3D DANTE-CUBE序列可见的动脉粥样硬化病变,其DCE-MRI数据纳入统计分析.观察者内的重复测量发现,Ve的一致性很好[组内相关系数(ICC):0.812;变异系数(CV):24.03％],CER的一致性较好(ICC:0.483;CV:18.7％).观察者间的重复测量发现,仅CER的一致性较好(ICC:0.439;CV:19.55％).重复扫描的分析虽然显示2次扫描的差异无显著性(P>0.05),但各参数的一致性不同程度欠佳.结论 DCE-MRI技术对动物较小斑块测量的可重复性整体上未达到良好水平,将来在后处理软件等方面有待改进和探索.

Objective:To explore the value of 3.0 T high resolution MRI (HR-MRI) in the follow-up of drug treatment in acute and non-acute ischemic stroke caused by middle cerebral artery (MCA) plaque.Methods:The perspective study enrolled patients with ischemic stroke caused by MCA stenosis from October 2012 to October 2015 in the department of Neurology and Neurosurgery of Changhai Hospital Affiliated to Naval Medical University. All the patients underwent HR-MRI and then were divided into acute and non-acute stroke groups according to the intervels of the last symptom onset to the time of HR-MRI examination. All patients were informed consent to receive antiplatelet drug and intensive lipid therapy and followed up with HR-MRI. The HR-MRI sequence including T 2WI, T 1WI and contrast-enhanced T 1WI of vessel wall, and T 2WI and DWI of brain were routinely performed. T-test of paired samples was used to evaluate the changes of stenosis rate of vascular lumen, plaque enhancement degree, plaque volume and plaque burden on HR-MRI, and the NIHSS score of nervous system and blood biochemical indicators of the patients before and after treatment. Chi square test was used to compare the difference in ischemic event recurrcence between the acute and the non-acute stroke group. Results:A total of 31 acute stroke patients and 20 non-acute stroke patients were enrolled in the study. The mean follow-up time of acute stroke group was (671.71±522.86) days. Compare with the baseline, the stenosis rate of vascular lumen ( P=0.039), plaque enhancement degree ( P<0.001), plaque volume ( P=0.024) and plaque burden ( P=0.031) were all improved after the drug treatment, the NIHSS score of nervous system was also significantly improved, and the levels of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) in 12 patients were significantly decreased. The mean follow-up time of patients with non-acute stroke was (695.35±555.90) days. The stenosis rate of vascular lumen, plaque enhancement degree, plaque volume and plaque burden were slightly improved, but without statistical significance ( P>0.05). There were no significant changes in NIHSS score of nervous system, TC, triglyceride (TG) and LDL-C ( P>0.05), however the high density lipoprotein cholesterol (HDL-C) was significantly increased than that in the baseline ( P=0.02). During the follow-up period, no new cerebral infarction was found in the DWI images of the two groups. Six patients had transient ischemic attack (TIA) recurrence in the acute stroke group and 5 patients in the non-acute stroke group, there was no significant difference between both groups(χ 2=0.229, P= 0.632). Conclusion:HR-MRI can be used as an important evaluation method for the follow-up of MCA atherosclerotic plaque therapy. After antiplatelet therapy and intensive lipid-lowering therapy, the plaque volume and burden of MCA offending plaque, and plaque enhancement decreased in acute stroke patients but there was no significant change in non-acute patients.

Purpose The development of straightforward classification methods is needed to identify unstable aneurysms and rupture risk for clinical use. In this study, we aim to investigate the relative importance of geometrical, hemodynamic and clinical risk factors represented by the PHASES score for predicting aneurysm wall enhancement using several machine-learning (ML) models. Methods Nine different ML models were applied to 65 aneurysm cases with 24 predictor variables. ML models were optimized with the training set using tenfold cross-validation with five repeats with the area under the curve (AUC) as cost parameter. Models were validated using the test set. Accuracy being significantly higher (p < 0.05) than the non-information rate (NIR) was used as measure of performance. The relative importance of the predictor variables was determined from a subset of five ML models in which this information was available. Results Best-performing ML model was based on gradient boosting (AUC = 0.98). Second best-performing model was based on generalized linear modeling (AUC = 0.80). The size ratio was determined as the dominant predictor for wall enhancement followed by the PHASES score and mean wall shear stress value at the aneurysm wall. Four ML models exhibited a statistically significant higher accuracy (0.79) than the NIR (0.58): random forests, generalized linear modeling, gradient boosting and linear discriminant analysis. Conclusions ML models are capable of predicting the relative importance of geometrical, hemodynamic and clinical parameters for aneurysm wall enhancement. Size ratio, PHASES score and mean wall shear stress value at the aneurysm wall are of highest importance when predicting wall enhancement in cerebral aneurysms.

Background The assessment of apparent diffusion coefficient (ADC) repeatability is important to body diffusion weighted imaging (DWI). However, data onto evaluating the repeatability of ADC values for normal pancreas are limited. The aim of this study was to evaluate the ADC test-retest repeatability of the normal pancreas.Methods Twenty-six healthy volunteers (mean 47.6 years; 13 men) were included and scanned twice with reposition using a DWI sequence at 3.0-T. ADCs of the pancreatic head, body and tail for two DWIs were measured by two readers. The mean ADCs of the pancreatic head, body and tail were calculated as the global pancreatic ADC. Test-retest repeatability and agreement of ADC measurement were evaluated by the Bland-Altman analysis, intra-class correlation coefficient (ICC) and coefficient of variation (CV).Results The global pancreatic ADC showed the best test-retest repeatability (mean difference ± limits of agreement were 0.05 ± 0.25×10 -3 mm 2 /s; ICC, 0.79; CV, 6%). Test-retest repeatabilities for ADC of pancreatic head, body or tail were scattered, with mean difference ± limits of agreement between two tests were 0.03 ± 0.47, 0.05 ± 0.42 and 0.06 ± 0.31 (×10 -3 mm 2 /s), respectively (ICCs, 0.81, 0.52 and 0.68; CVs, 9%, 8% and 8%). Both intra-observer repeatability and inter-observer reproducibility were acceptable for whole pancreas between ADC measurements of the two DWIs.Conclusions ADC values of the pancreas are technically challenging and repeatability is variable. Cautions should be taken when interpreting longitudinal clinical changes in ADC values of the normal pancreas because the measurements do have an inherent variability by locations.

目的:评估IVIM-DWI相关定量参数(ADCslow、ADCfast、f)和DWI单指数模型的定量参数(ADCstandard)在鉴别附件肿块良恶性中的诊断价值.方法:将59例行多b值(15个b值,范围0～3500 s/mm2)DWI检查并经临床(1例)和病理证实(58例)的附件肿块患者纳入研究,其中附件恶性肿瘤32例,良性病变27例.由两位医师分别测量病灶的各项定量参数值(ADCstandard、ADCslow、ADCfast和f).采用组内相关系数(ICC)评估两位观察者之间各项参数测量值的一致性.采用两独立样本非参数Mann Whitney U检验或t检验对良恶性组之间各项定量参数值的差异进行分析.采用受试者工作特征(ROC)曲线分析各项定量参数诊断附件恶性病变的诊断效能.结果:两位医师测量的各项DWI定量参数值的差异均无统计学意义(P＞0.05),各项参数在两位医师间的一致性均较好(ICC为0.846～0.959).四项定量参数中ADCstandard、ADCslow及f值在良恶性组之间的差异有统计学意义(P＜0.05).ROC曲线分析显示,ADCstandard、ADCslow及f的曲线下面积分别为0.890、0.893和0.630.结论:多b值DWI检查中ADCstandard及ADCslow对附件良恶性病变的鉴别诊断价值较高,而ADCfast和f的鉴别诊断价值相对较小.

Objective To investigate the characteristics of histogram analysis and differences of apparent diffusion coefficient ( ADC) for normal pancreas with different diffusion gradients of diffusion weighted imaging (DWI) at 3. 0T. Methods Three unidirectional diffusion gradients (X, Y or Z direction) and three orthogonal diffusion gradient DWI data of 21 volunteers with normal pancreas were retrospectively analyzed. The histogram parameters of mean ADC, percentile, skewness, peak and the like were measured based on home-made DWI post-processing software, and the differences on histogram parameters obtained from 4 different diffusion gradients were compared by using Kruskal Wallis test. Results There was no significant difference on the mean ADC, skewness, percentile and the like for normal pancreas among 3 unidirectional diffusion gradients and tri-orthogonal diffusion gradient DWIs, but there was significant difference on the mean kurtosis value ( X:3. 16 ± 1. 44, Y:4. 72 ± 2. 26, Z:4. 47 ± 2. 1, tri-orthogonal:3. 69 ± 1. 82; χ2 = -9. 84, P=0. 02). Further analyses results showed that the ADC kurtosis of normal pancreas obtained from X-directional diffusion gradient DWI was significantly smaller than that of the direction of Y or Z, and the difference was statistically significant (P<0.05). Conclusions The ADC kurtosis of normal pancreas is related to the direction of diffusion gradient in DWI, and the ADC kurtosis of normal pancreas obtained by X-direction diffusion gradient is the smallest.

目的 优化巴马小型猪颈动脉管壁HR-MRI技术并进行重复性验证,为小型猪颈动脉管壁病变的定性和定量研究奠定技术基础.方法 运用3.0T MRI仪对3只健康巴马小型猪的颈动脉管壁行高分辨2D FSE T2WI、T1WI及T1WI增强扫描及参数优化,重复测量和计算双侧颈动脉的管腔面积(LA)、血管总面积(TA)及管壁面积(WA),变异系数(CV)和组内相关系数(ICC)评估观察者间和观察者内的一致性.结果 双侧颈动脉的LA、TA和WA均有较高的观察者间一致性:CV均小于15％;ICC均大于0.4,其中所有序列的LA和TA的ICC均大于0.90,T1WI和T1WI增强序列的LA、TA和WA的ICC均大于0.75;观察者间测量的差异无显著性(P＞0.05).观察者内的一致性也较高:CV均小于15％;ICC均大于0.4,其中LA和TA的ICC均大于0.95;观察者内测量的差异无显著性(P＞0.05).结论 本研究的HR-MRI优化方案提高了图像质量,可用于巴马小型猪的颈动脉管壁形态学的定量研究.

目的 评估高分辨率磁共振管壁成像技术在双侧及单侧烟雾病管壁特征中评估及鉴别诊断的价值.方法 46例确诊的烟雾病患者(双侧31例,单侧15例)均进行高分辨率磁共振管壁成像扫描.描述性分析烟雾病患者的临床特征,并将临床及管壁特征与之相匹配的颅内大脑中动脉粥样硬化狭窄的患者的特征进行对照.结果 颅内动脉粥样硬化患者更易合并高血脂及糖尿病,且血管外径、管壁厚度及重塑指数均高于烟雾病患者(P值均<0.001).双侧及单侧烟雾病的血管外径及重塑指数无统计学差异,但单侧烟雾病的管壁厚度(0.30±0.01)mm小于双侧烟雾病(0.51±0.12)mm(P<0.001).烟雾病更易累及颈内动脉末端分叉部,增强后颅内动脉粥样硬化强化多较明显,且多为偏心性强化.结论 烟雾病具有不同于动动脉粥样硬化的管壁特征.单侧烟雾病的大部分管壁特征与双侧烟雾病相似,但管壁厚度较双侧小.