Value of diffusion-weighted imaging in distinguishing pancreatic carcinoma from mass-forming chronic pancreatitis: a meta-analysis

Background Several previous studies have shown that diffusion-weighted imaging （DWl） can provide additional information for focal pancreatic lesions by demonstrating more restricted diffusion in solid malignant tumors than in chronic pancreatitis, which can be indicated by a decreased apparent diffusion coefficient （ADC）. However, these studies have a modest sample size and convey inconclusive results. The aim of this study was to determine, in a meta-analysis, the diagnostic performance of quantitative diffusion-weighted magnetic resonance imaging in distinguishing pancreatic carcinoma from mass-forming chronic pancreatitis. Methods We determined the sensitivities and specificities across studies. A summary receiver operator characteristic （sROC） curve was constructed to calculate the area under the curve （AUC）. Results The pooled sensitivity of DWI was 0.86 （95% Cl： 0.80-0.91） and the pooled specificity was 0.82 （95% CI： 0.72- 0.89）. The AUC of the sROC was 0.91 （95% CI： 0.88-0.93）. Conclusions DWl may be a potentially technically feasible tool for differentiating pancreatic carcinoma from mass- forming chronic pancreatitis. However, large-scale randomized control trials are necessary to assess its clinical value.     

Evaluating transcatheter arterial chemoembolization for primary hepatic cancer by magnetic resonance diffusion-weighted imaging

Hepatic cancer is associated with very high mortality and morbidity, and the world＇s highest morbidity and mortality rates for this malignant tumor are found in China. Each year, the number of people who die of hepatic cancer in China amounts for 53% of the world total. Although resection is the first-choice treatment for hepatic cancer, only 20%-30% of patients have the opportunity to undergo resection. Transcatheter arterial chemoembolization （TACE） is a typical intervention therapy. Its advantages include minimal trauma, precise efficacy,     

Cardiovascular magnetic resonance imaging findings in children with myocarditis

Background Myocarditis is a common,potentially life-threatening disease that presents a wide rang of symptoms in children,as an important underlying etiology of other myocardial diseases such as dilated and arrhythmogenic right ventricular cardiomyopathy.The incidence of nonfatal myocarditis is probably greater than that of the one actually diagnosed,which is the result of the challenges of establishing the diagnosis in standard clinical settings.Currently,no single clinical or imaging finding confirms the diagnosis of myocarditis with absolute certainty.Historically,clinical exam,electrocardiogram （ECG）,serology and echocardiography had an unsatisfactory diagnostic accuracy in myocarditis.Endomyocardial biopsy remains as a widely accepted standard,but may not be suitable for every patient,especially for those with less severe disease.Our aim was to find the changes in cardiovascular magnetic resonance （CMR） imaging of children with myocarditis diagnosed by clinical criteria.Methods We studied 25 children （18 male,7 female; aged from 5-17 years） with diagnosed myocarditis by clinical criteria.CMR included function analyses,T2-weighted imaging,T1-weighted imaging before and after i.v.gadolinium injection （early gadolinium enhancement （EGE） and late gadolinium enhancement （LGE））.Results The T2 ratio was elevated in 21 children （84％,11 in anterolateral （44％）,5 in inferolateral （20％）,and 5 in septum （20％））,EGE was present in 9 children （36％,3 in anterolateral （12％）,4 in inferolateral （20％）,and 2 in septum （8％））,and LGE was present in 5 children （20％,2 in anterolateral （8％）,1 in inferolateral （4％）,1 in septum （4％）,and 1 in midwall of left ventricular （LV） wall）.In 9 children （36％）,two （or more） out of three sequences （T2,EGE,LGE） were abnormal.Conclusions The CMR findings in children with clinically diagnosed myocarditis vary within the groups,including regional or global myocardial signal increase in T2-w     

MRI在肿瘤血管生成研究中的初步应用

肿瘤血管生成是肿瘤发生发展过程中的重要事件,MRI是研究肿瘤血管生成的影像学手段之一,其中动脉自旋标记法、血氧水平依赖效应的功能成像法无需造影剂增强,在评估肿瘤血管上具有一定价值,但因技术条件限制应用有限。增强MRI可以半定量或定量地反映肿瘤灌注及血管通透度等特性,研究结果受对比剂的类型和技术方法等的影响。MRI分子影像技术在肿瘤血管生成研究中具有重要意义,目前主要用于干细胞标记和血管靶显像方面．细胞内示踪剂和靶向对比剂的研究是该技术能够发展成熟的关键。     

乳腺癌保乳手术MRI影像学证据的多中心前瞻性研究

Background This multicenter prospective study aimed to assess the utility of dynamic enhanced magnetic resonance imaging （MRI） prior to breast-conserving surgery for breast cancer.Methods The research subjects were drawn from patients with primary early resectable breast cancer treated in the breast disease centers of six three-level hospitals in Beijing from 1 January 2010 to 31 December 2012.The participants were allocated to a breast-conserving surgery group （breast-conserving group） or a total mastectomy group （total mastectomy group）.Enhanced MRI was used to measure breast volume,longest diameter of tumor and tumor volume.The correlations between these measurements and those derived from histopathologic findings were assessed.The relationships between the success rate of breast-conserving surgery and MRI-and pathology-based measurement results were statistically analyzed in the breast-conserving group.Results The study included 461 cases in the total mastectomy group and 195 in the breast-conserving group.Allocation to these groups was based on clinical indications and patient preferences.The cut-off for concurrence between MRI-and pathology-based measurements of the longest diameter of tumor was set at 0.3 cm.In the total mastectomy group,the confidence interval for 95％ concurrence of these measurements was 35.41％-44.63％.Correlation coefficients for MRI and histopathology-based measurements of breast volume,tumor volume and tumor volume/breast volume ratio were r=0.861,0.569,and 0.600,respectively （all P ＜0.001）.In the breast-conserving group,with 0.30 cm taken as the cut-off for concurrence,the 95％ confidence interval for MRI and pathology-based measurements of the longest diameter of tumor was 29.98％-44.01％.The subjective and objective success rates for breast-conserving surgery were 100％ and 88.54％,respectively.Conclusions There were significant correlations between dynamic enhanced MRI-and histopathology-based measurements of the longest diameter of breast lesions,breas     

Associations among cerebral microbleeds, cerebral large-artery diseases and endothelial function

Background Endothelial dysfunction is not only an early stage of atherosclerosis,but also involved in the pathogenesis of cerebral small-vessel diseases.Patients with cerebral microbleeds （CMBs） may have arteriolosclerosis as well as systemic atherosclerosis.However,little is known about the associations among CMBs,atherosclerosis of cerebral large arteries,and endothelial function.Our study aimed to investigate the relationships among them.Methods This was a cross-sectional study.Ninety patients hospitalized in Peking University First Hospital with acute ischemic stroke were enrolled consecutively between November 1,2007 and January 31,2008.All subjects underwent transcranial Doppler and carotid color duplex ultrasonography to record the intima-media thickness （IMT） of common carotid artery,carotid plaque,and cerebral artery stenosis.Brain magnetic resonance imaging （MRI） routine sequences and gradient recall-echo T2＊-weighted imaging were performed to count CMBs with clinical data blindness.Endothelial function was evaluated using flow-mediated dilation （FMD） and nitroglycerin-mediated dilation （NMD） of the brachial artery.FMD and NMD were examined by an experienced vascular sonographer using a high-resolution ultrasound.Results Thirty cases （33.3%） had CMBs with counts ranging from 1 to 30.Both FMD （（9.9＆#177;4.8）% vs.（15.2＆#177;7.4）%,P=0.001） and NMD （（13.7＆#177;6.1）% vs.（19.0＆#177;7.4）%,P=0.001） were significantly decreased in CMB-positive patients than in CMB-negative patients.No significant relationships were demonstrated between CMBs and intracranial and/or extracranial artery stenosis.The frequencies of CMBs in patients with IMT≥1.0 mm,carotid plaque,and extracranial artery stenosis were 37.5%,39.4%,and 47.6% respectively,with no significant difference,but much higher than in patients with IMT 〈1.0 mm （5%,P 〈0.05）.In Logistic regression analysis,impaired FMD （OR=5.783,95% CI 1.652-6.718,P=0.007） and high pulse pressure （OR=6.228,95     

Magnetic resonance imaging of disc space infection revisited: temporal changes

Background Magnetic resonance imaging （MRI） has advantages in showing pathologic changes of disc space infection,which is important in clinical treatment.The purpose of this study was to describe the MRI findings of disc space infections in relation to chronicity.Methods MRI of 60 patients from January 1,2002 to April 30,2012 in Ottawa Hospital were retrospectively evaluated by two radiologists blindly.All patients had histological confirmation,with 55 having microbiological confirmation as well.These patients were divided into acute （n=18）,subacute （n=21） and chronic （n=21） based on histological findings.The following potential signs of MRI finding were assessed：marrow edema,endplate erosions,disk fluid and height change,paraspinal mass,epidural collection,facet fluid and enhancement in the marrow,disc,paraspinal mass,and epidural involvement.Statistical analysis consisted of t-or F-tests and chi-square test.Results In the 60 patients,83 infected discs （single disc in 45 patients,2-4 discs in 15 patients） were found,including 22 discs in the acute group,30 discs in the subacute group,and 31 discs in the chronic group.There was a significant difference in the extent of marrow edema between the acute,subacute and chronic groups （P ＜0.05）,with a gradually increasing extent from acute to chronic.The extent of endplate erosions increased with chronicity,but was not statistically significant.There were significant differences in the disc fluid,epidural collection,and disc enhancement among the acute,subacute and chronic groups,as well as the facet fluid between acute and chronic groups （P ＜0.05）.There were no significant differences in the present probability of disc height loss,paraspinal mass,and marrow enhancement among the three groups （P ＞0.05）.Conclusions From acute to chronic infections,the extent of marrow edema and endplate erosions appeared to gradually increase.Epidural collections and facet fluid are most frequently found in the acute group,while disc fluid and disc     

Three-dimensional-fast imaging employing steady-state acquisition and T2-weighted fast spin-echo magnetic resonance sequences on visualization of cranial nerves Ⅲ-Ⅻ

Because of the small diameter and complex anatomic course of the cranial nerves except for the optic nerve, trigeminal nerve, facial nerve, and cochlear and vestibular nerve, other cranial nerves are difficult to be visualized in magnetic resonance imaging （MRI） scanning with conventional thickness （5-10 mm）. With the rapid development of MRI technology high spatial resolution, three-dimensional and two-dimensional magnetic resonance imaging technologies have been used in recent years in the observation of normal and abnormal cranial nerves, including three-dimensional constructive interference in steady state （3D CISS） sequence, three- dimensional magnetization-prepared rapid gradient-echo （3D MP-RAGE） sequence, three-dimensional fast inflow with steady-state precession （3D FISP） seohuence, and some fast spin-echo （FSE） sequences. - Threedimensional fast imaging employing steady-state acquisition （3D-FIESTA） is a fast three-dimensional steady-state imaging sequence with high spatial resolution and contrast between the organizational structures. And this sequence was reportedly used in the study on the diseases in the cerebellopontine angle; inner ear and posterior fossa tumors.7＇8 However, the reports about the value of 3D-FIESTA sequence for the visualization of normal cranial nerves are still rare.     

Hyperperfusion of Multiple Sclerosis Plaques Characterized by 3D FSE Arterial Spin Labelling

MULTIPLE sclerosis （MS） is a common inflammatory demyelinating disorder of central nervous system, and the disease burder could be well evaluated by conven-tional magnetic resonance imaging （MRI）,1 including T2-weighted, fluid-attenuatd inversion recovery, and postcontrast Tl-weighted sequences. 2 We investigated the perfusion state of MS plaques using brain perfusion imaging in a 12-year-old boy with MS.     

DWI及动态增强MRI在淋巴结病变鉴别诊断中的价值

目的探讨磁共振扩散加权成像（D硼以及动态增强MPI（DCE-Mm）在颈部淋巴结病变鉴剐诊断中的价值。方法使用GE1．5T磁共振扫描仪及颈部相控阵线圈,46例单侧或双侧颈部淋巴结肿大患者（26例恶性病变,20例良性病变）。全部病例使用体线圈行SE-EPI DWI序列扫描,采用全方位扩散梯度及6个b值扫描。DWI扫描时间40-52S。分析46例病例中淋巴结的D研与表现扩散系数（ADC）值的特点,并行动态增强MRI和常规MRI增强检查,分析比较良、恶性淋巴结病变的MRI征象,计算病灶峰值增强率Emax,峰值时间Tmax．最大强化速率Slopemax,并根据病变最高强化区ROI的测量值,绘制病灶的时间一信号强度曲线（SI-Time曲线）。结果在DⅥ序列扫描中,良性和恶性淋巴结均呈高信号,恶性淋巴结组的平均ADE值为（0．834±0．192）x10^-3mm^2／s,良性淋巴结组为（1．687±0．252）×100mm^2／s,恶性淋巴结组平均ADC值明显小于良性淋巴结组（P〈0．05）,两者间差异有统计学意义。良性淋巴结病变时间一信号强度曲线多表现为I型,而恶性淋巴结多为Ⅲ型,Ⅱ型曲线均可见于良性和恶性淋巴结病变。结论D册可作为颈部良、恶性淋巴结病变鏊别诊断的一种快速可行的新方法,具有一定的临床价值。通过动态增强进一步揭示病变的血流动力学特征。有助于对淋巴结病变作出准确的定性诊断,更能有效地鉴别诊断良、恶性淋巴结病变。     

Is ecstasy-induced protracted symptom of motion perception associated with altered regional homogeneity of brain？

The synthetic hallucinogen 3,4-methylenedioxymet hamphetamine （MDMA） is the main psychoactive constituent of the popular recreational drug ＂ecstasy.＂ Whether its neurotoxic effects are fully reversible is unknown. Here we report a patient with protracted syndrome induced by ecstasy.     

Primary pulmonary artery chondrosarcoma: the use of different imaging modalities

Fewer than 300 patients with primary pulmonary artery sarcoma have been reported since 1923,when it was first described by Mandelstamm.1 The diagnosis of pulmonary artery sarcoma is difficult,and misdiagnosis as chronic pulmonary embolism often occurs.Herein,we reported a case of primary pulmonary artery chondrosarcoma.So far as we know,this patient served as the first case ever reported to receive computed tomography pulmonary angiography （CTPA）,gadolinium enhanced magnetic resonance imaging （MRI）,and positron emission tomography/computed tomography （PET/CT） before surgery.By these means,the utility of different imaging modalities for pulmonary artery sarcoma was well demonstrated.Keywords：primary pulmonary artery chondrosarcoma; computed tomography pulmonary angiography;magnetic resonance imaging; positron emission tomography     

Application of immunosuppressant facilitates the therapy of optic neuritis combined with Sj（o）gren＇s syndrome

Background Optic neuritis （ON） is often the first symptom of multiple sclerosis （MS） and neuromyelitis optica （NMO） while there has been very little research reported on ON combined with Sj（o）gren＇s syndrome （SS）.The aim of this study is to provide different treatments and services for and NMO patients combined with SS.Methods Twenty-seven patients with ON combined SS were divided into two groups：corticosteroid group （C group,methylprednisolone sodium succinate,14 patients） and corticosteroid＋ immunosuppressant group （C＋I group,leflunomide,13 patients）.ON relapse times in 1 year after treatment,number of patients who relapsed to NMO/MS in 1 years,visual acuity and retina nerve fiber layer （RNFL） thickness were measured.Mann Whitney-Wilcoxon test was used to compare continuous variables and Chi-square test or Fisher＇s exact test was to compare proportions.Results ON combined with SS patients had higher incidence rates in middle-aged women who have binocular damage and heavier visual function damage or when there is an easy relapse,and the patients are often hormone dependent.The patients are more likely anti-aquaporin-4 IgG seropositive （70.4％）.They are liable to form a centrocecal scotoma and tubular vision.The times of relapse decreased in patients who used immunosuppressant,and a significant difference was found between immunosuppressant and non-immunosuppressant groups in visual acuity recovery during 6-month followup period （P ＜0.05）; however,the RNFL thickness at the four quadrants was not significantly different.Conclusions The effect of immunosuppressant plus corticosteroid on the early onset of ON combined with SS was to provide ON remedy and to prevent recurrence in clinics.This study provides a significant reference for the prevention and treatment of ON on the basis of immunosuppressant and corticosteroid.     

Multimodality imaging assessments of response to metformin therapy for breast cancer in nude mice

Background Metformin is the most widely used anti-diabetic drug in the world.An increasing body of evidence shows metformin also blocks cell cycle progression and selectively induces apoptosis via caspase activation in some breast tumor cells.Diffusion-weighted imaging （DWl） and bioluminescence imaging （BLI） have great potential in the evaluation of the early response to cancer therapies.We used DWl and BLI in evaluating the response of breast cancer to metformin.Methods The luciferase-engineered human breast cancer cell line MDA-MB-231 was inoculated into the mammary fat pad of nude mice.Twelve female nude mice bearing tumors were divided into two groups.The mice in the treatment group received metformin （2 mg/ml in drinking water daily） after tumor inoculation,and the mice in the control group were offered drinking water without any drug added.We performed 7T magnetic resonance imaging and optical imaging every week.Imaging included T1-and T2-weighted imaging,DWl,and BLI.After imaging.The tumors were collected and subjected to histological analysis.Results The mean photons/second of tumors in the treatment group was （3.00±0.43）×106 at day one,（1.01±0.14）×107 at 2 weeks,（5.79±1.42）×107 at 4 weeks,and （2.33±0.70）×107 at 8 weeks.The mean photons/second of tumors in the control group was （3.29±0.59）×106 at day one,（3.59±0.63）×107 at 2 weeks,（3.87±0.56）×108 at 4 weeks,and （4.12±1.72）x108 at 8 weeks.Compared to the control group,the treatment group showed an obvious decrease in the mean bioluminescence （photons/s） of the tumors and fewer metastases.Histological examination confirmed the presence of fewer metastases.DWI showed the apparent diffusion coefficient （ADC） value of the tumors; the mean ADC value was （0.9287±0.04346）x10-3 mm2/s in the treated tumors and （0.7553±0.01804）x103 mm2/s in the untreated tumors.The ADC value of tumors in the treatment group was significantly higher than the control tumors （P=0.0013）.Conclusions The growth and metastasis of MDA-MB-231 breast cancer may be inhibited by metformin.DWI and BLI have great potentials in the evaluation of the early response to metformin treatment.BLI has a high degree of sensitivity and is able to detect micrometastasis,thus can be used for identifying tumor metastasis in vivo.     

Magnetic resonance study of the structure and function of the hippocampus and amygdala in patients with depression

Background The hippocampus and amygdala exhibit structural and functional alterations in patients with depression. The objective of this study was to investigate the structural and functional relationships between these core regions. Methods Based on the severity of their condition, 60 patients and 20 healthy controls were equally divided into four groups （mild group, moderate group, major group and health controls group）, scanned by T1-MR, functional magnetic resonance imaging （fMRI）, and susceptibility weighted imaging （SWI）. Structural image, BOLD image, and SWI image were collected for processing and analysis. The characteristics of the depression and controls were checked by analysis of variance test, and the difference between groups was checked by Dunnett＇s test. Results The volume of hippocampus and amygdala varied with the severity of the condition. The signal obtained under the stimulation of negative events was linearly decreased in the mild, moderate and major groups revealed by fMRI. The length and diameter of the lateral ventricle vein was reduced in the mild group, whereas the number of branches increased. In the moderate and major groups, the reduction in the length, diameter and increase in the number of branches of the lateral ventricle vein were greater. Conclusion The alterations of the volume, fMRI, and cerebral veins in these core regions may account for the causal relationship between structure and function.     

泌尿系结石DR成像的临床实用性研究

泌尿系统影像学经历了漫长的岁月,静脉尿路造影(IVP)一直沿用至今,当前研究的方向一是泌尿系统功能影像学研究,二是更精细的形态学研究[1]。作者利用DR摄影对结石的形态、成分、硬度进行分析,指导体外冲击波碎石(ESWL),以减少并发症,提高成功率。特报道如下。1资料与方法1.1资料我院1995年引进WDESWL—91碎石机,截止2005年1月已成功治愈泌尿系统结石患者3100例,搜集资料完整结石标本500例晾干装瓶,按颜色排列(褐354例、黄7例、灰白139例)。1.2方法用北京万东新东方1000A直接数字化成像系统,像素在900万以上,分别对褐色结石、灰白色结石和黄色结石进行摄影,每10例为一排,单个结石为0.3cm～0.7cm,结石粉末不参与摄影。医用工作站电脑放大5倍变换窗宽窗位充分显示结石内部细微结构。DIASYS—尿液沉渣分析仪分析尿液酸碱度和结晶成分。2结果2.1褐色结石DR像可见环状分层、放射斑纹和致密影中混有小颗粒减低区,边缘锐利似刀切,尿液为酸性,找到草酸钙结晶,质地坚硬粗糙。2.2灰白色结石DR像层纹明显,呈条、点混杂影,且不均匀,颗粒状点影较多,边缘略毛糙,质地较硬,尿液碱性,找到磷酸钙...     

超声技术在乳腺肿瘤良恶性鉴别中的应用价值分析

我院对2010年3月—2013年3月179例乳腺肿块患者进行彩色多普勒超声检查,结合超声新技术弹性成像评分,判断其良恶性,为临床治疗和手术方式的选择提供依据[1],并将超声诊断结果与手术病理对照,现报告如下。 1资料与方法 1.1一般资料 179例患者中167例为女性,12例为男性,年龄19～76岁,平均年龄47.5岁。全部进行超声检查后手术切除,并行病理检查。     

Evaluation of Ventricular-vascular Coupling in Patients with Type 2 Diabetes Mellitus Using 2-Dimensional Speckle Tracking Imaging

The elastic and functional coupling of heart and vessels makes the stroke work （SW） of the heart optimal. Speckle tracking imaging （STI） can evaluate the myocardial strain and function. We studied ventricular-vascular coupling in 80 diabetic patients with different systolic function using STI. The patients were divided into two groups according to ejection fraction （EF）： the diabetes mel- litus with normal EF （DMN） group and the diabetes mellitus with abnormal EF （DMA） group. Forty-two volunteers served as control group. The relative wall thickness （RWT）, left ventricular mass index （LVMI）, stroke volume （SV）, SW, rate-pressure product （RPP）, systemic vascular resis- tance index （SVRI）, left ventricular end-systolic elastance （Ees）, effective arterial elasticity （Ea） and ventricular-vascular coupling index （VVI） were measured and calculated by conventional echocardi- ography. The longitudinal strain （LS） at basement （LSBA）, papillary muscle （LSvM） and cardiac apex （LSAv） was assessed with STI. It was found： （A） compared with control group, in DMN and DMA groups, LSBA, LSvM and LSAp decreased, and they were lower in DMA group. （B） VVI, RPP and SVRI increased, and they were higher in DMN group; Ees decreased, and it was lower in DMA group. （C） LSBA, LSpM, and LSAv had negative correlation with VVI. LSAp, RWT, LVMI and SW were independent predictors for VVI. The area under the receiver operating characteristic （ROC） curves was used for identification of DMA and DMN with LSBA, LSpM, and LSAp, and the area under the ROC of LSAp was the largest. This study supports that myocardial LS could reflect the ventricu- lar-vascular coupling. Different segments had an order to “respond to” the state of the coupling, and the cardiac apex might be the earliest.     

Diffusion-weighted magnetic resonance imaging with short T1 inversion recovery-echo planar imaging combined with dual-head coincidence single photon emission computed tomography for diagnosing solitary pulmonary nodule

Positron emission tomography （PET） using 18F-fluorodeoxyglucose （FDG） has not been widely used in China for expensive cost （$1200）. Dual-head coincidence single photon emission computed tomography （DHC-SPECT） can depict many of the lesions depicted with a PET scanner in the lungs, which is used in place of PET-CT for discriminating malignant from benign pulmonary nodules in many studies. However, DHC-SPECT has inevitable false-negative results because the sensitivity for small lesions less than 2.0 cm is limited, and has high false-positive rate for active inflammatory nodules. Furthermore,DHC-SPECT also has a considerably higher cost （$300 in China） than other imaging examination.     

Loeffler endocarditis: magnetic resonance imaging features of pre- and post-operation

Loeffier endocarditis is clinically presented as restrictive cardiomyopathy, which is the least common of the three major categories of cardiomyopathic disorders.1 The endomyocardial fibrosis was considered as its main pathophysiologic changes.24 Generally speaking, the characteristics include thickening of the apex and inflow tracts of one or both ventricles, and the papillary muscle and chordae tendineae also can be involved in some cases.