Femoroacetabular impingement is uncommonly associated with a large rim fragment of bone along the superolateral acetabulum. We report an unusual case of femoroacetabular impingement(FAI) with chronic acetabular rim fr...Femoroacetabular impingement is uncommonly associated with a large rim fragment of bone along the superolateral acetabulum. We report an unusual case of femoroacetabular impingement(FAI) with chronic acetabular rim fracture. Radiographic, 3D computed tomography, 3D magnetic resonance imaging and arthroscopy correlation is presented with discussion of relative advantages and disadvantages of various modalities in the context of FAI.展开更多
An infant male presented with the rare anatomy consisting of situs solitus,concordant atrioventricular connections to L-looped ventricles,double outlet right ventricle(DORV),and hypoplastic aortic arch.6 months after ...An infant male presented with the rare anatomy consisting of situs solitus,concordant atrioventricular connections to L-looped ventricles,double outlet right ventricle(DORV),and hypoplastic aortic arch.6 months after neonatal aortic arch repair,the morphologic right ventricle function deteriorated,and surgical evaluation was undertaken to determine if either biventricular repair with a systemic morphologic left ventricle or right ventricular exclusion was possible.After initial echocardiography,magnetic resonance imaging(MRI)was used to create detailed axial and 4-dimensional(4D)images and 3-dimensional(3D)printed models.The detailed anatomy of this rare,complex case and its use in pre-surgical planning is presented.展开更多
This study is to compare three-dimensional(3D)isotropic T2-weighted magnetic resonance imaging(MRI)with compressed sensing-sampling perfection with application optimized contrast(CS-SPACE)and the conventional image(3D...This study is to compare three-dimensional(3D)isotropic T2-weighted magnetic resonance imaging(MRI)with compressed sensing-sampling perfection with application optimized contrast(CS-SPACE)and the conventional image(3D-SPACE)sequence in terms of image quality,estimated signal-to-noise ratio(SNR),relative contrast-to-noise ratio(CNR),and the lesions’conspicuous of the female pelvis.Thirty-six females(age:51,28-73)with cervical carcinoma(n=20),rectal carcinoma(n=7),or uterine fibroid(n=9)were included.Patients underwent magnetic resonance(MR)imaging at a 3T scanner with the sequences of 3D-SPACE,CS-SPACE,and twodimensional(2D)T2-weighted turbo-spin echo(TSE).Quantitative analyses of estimated SNR and relative CNR between tumors and other tissues,image quality,and tissue conspicuity were performed.Two radiologists assessed the difference in diagnostic findings for carcinoma.Quantitative values and qualitative scores were analyzed,respectively.The estimated SNR and the relative CNR of tumor-to-muscle obturator internus,tumor-to-myometrium,and myometrium-to-muscle obturator internus was comparable between 3D-SPACE and CS-SPACE.The overall image quality and the conspicuity of the lesion scores of the CS-SPACE were higher than that of the 3D-SPACE(P<0.01).The CS-SPACE sequence offers shorter scan time,fewer artifacts,and comparable SNR and CNR to conventional 3D-SPACE,and has the potential to improve the performance of T2-weighted images.展开更多
BACKGROUND Chronic cocaine use is associated with stroke, coronary artery disease and myocardial infarction, resulting in severe impairments or sudden mortality. In the absence of clear cardiovascular symptoms, indivi...BACKGROUND Chronic cocaine use is associated with stroke, coronary artery disease and myocardial infarction, resulting in severe impairments or sudden mortality. In the absence of clear cardiovascular symptoms, individuals with cocaine use disorder (iCUD) seeking addiction treatment receive mostly psychotherapy and psychiatric pharmacotherapy, with no attention to vascular disease (i.e., atherosclerosis). Little is known about the pre-clinical signs of cardiovascular risk in iCUD and early signs of vascular disease are undetected in this underserved population. AIM To assess inflammation, plaque burden and plaque composition in iCUD aiming to detect markers of atherosclerosis and vascular disease. METHODS The bilateral carotid arteries were imaged with positron emission tomography/magnetic resonance imaging (PET/MRI) in iCUD asymptomatic for cardiovascular disease, healthy controls, and individuals with cardiovascular risk. PET with 18F-fluorodeoxyglucose (18F-FDG) evaluated vascular inflammation and 3-D dark-blood MRI assessed plaque burden including wall area and thickness. Drug use and severity of addiction were assessed with standardized instruments. RESULTS The majority of iCUD and controls had carotid FDG-PET signal greater than 1.6 but lower than 3, indicating the presence of mild to moderate inflammation. However, the MRI measure of wall structure was thicker in iCUD as compared to the controls and cardiovascular risk group, indicating greater carotid plaque burden. iCUD had larger wall area as compared to the healthy controls but not as compared to the cardiovascular risk group, indicating structural wall similarities between the non-control study groups. In iCUD, wall area correlated with greater cocaine withdrawal and craving. CONCLUSION These preliminary results show markers of carotid artery disease burden in cardiovascular disease-asymptomatic iCUD. Broader trials are warranted to develop protocols for early detection of cardiovascular risk and preventive intervention in iCUD.展开更多
BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is imp...BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is important.AIM To investigate the diagnostic value of magnetic resonance multi-delay threedimensional arterial spin labeling(3DASL)and diffusion kurtosis imaging(DKI)in evaluating the perfusion and infarct area size in patients with acute cerebral ischemia.METHODS Eighty-four patients who experienced acute cerebral ischemia from March 2019 to February 2021 were included.All patients in the acute stage underwent magnetic resonance-based examination,and the data were processed by the system’s own software.The apparent diffusion coefficient(ADC),average diffusion coefficient(MD),axial diffusion(AD),radial diffusion(RD),average kurtosis(MK),radial kurtosis(fairly RK),axial kurtosis(AK),and perfusion parameters post-labeling delays(PLD)in the focal area and its corresponding area were compared.The correlation between the lesion area of cerebral infarction under MK and MD and T2-weighted imaging(T2WI)was analyzed.RESULTS The DKI parameters of focal and control areas in the study subjects were compared.The ADC,MD,AD,and RD values in the lesion area were significantly lower than those in the control area.The MK,RK,and AK values in the lesion area were significantly higher than those in the control area.The MK/MD value in the infarct lesions was used to determine the matching situation.MK/MD<5 mm was considered matching and MK/MD≥5 mm was considered mismatching.PLD1.5s and PLD2.5s perfusion parameters in the central,peripheral,and control areas of the infarct lesions in MK/MD-matched and-unmatched patients were not significantly different.PLD1.5s and PLD2.5s perfusion parameter values in the central area of the infarct lesions in MK/MD-matched and-unmatched patients were significantly lower than those in peripheral and control areas.The MK and MD maps showed a lesion area of 20.08±5.74 cm^(2) and 22.09±5.58 cm^(2),respectively.T2WI showed a lesion area of 19.76±5.02 cm^(2).There were no significant differences in the cerebral infarction lesion areas measured using the three methods.MK,MD,and T2WI showed a good correlation.CONCLUSION DKI parameters showed significant difference between the focal and control areas in patients with acute ischemic cerebral infarction.3DASL can effectively determine the changes in perfusion levels in the lesion area.There was a high correlation between the area of the infarct lesions diagnosed by DKI and T2WI.展开更多
目的探讨Radial 3D VIBE在儿童自由呼吸下腹部平扫获得T1加权图像的临床应用。方法选取我院2015年1月~2015年8月行腹部磁共振检查患者100例,T1加权图像均采用常规梯度回波序列和Radial 3D VIBE序列分别扫描。结果对两种扫描序列定性分析...目的探讨Radial 3D VIBE在儿童自由呼吸下腹部平扫获得T1加权图像的临床应用。方法选取我院2015年1月~2015年8月行腹部磁共振检查患者100例,T1加权图像均采用常规梯度回波序列和Radial 3D VIBE序列分别扫描。结果对两种扫描序列定性分析,结果表明Radial 3D VIBE序列得的信噪比和对比噪声比均显著高于常规序列,图像质量明显提高,能够清晰显示病变部位。与常规序列相比,Radial 3D VIBE序列出现呼吸运动伪影显著低于常规序列,P<0.05。结论 Radial 3D VIBE序列可提高磁共振成像分辨率,有效减少呼吸运动伪影,提高图像质量。展开更多
Background: Increased relative wall thickness in hypertensive left ventricular hypertrophy (LVH) has been shown by echocardiography to allow preserved shortening at the endocardium despite depressed LV midwall circumf...Background: Increased relative wall thickness in hypertensive left ventricular hypertrophy (LVH) has been shown by echocardiography to allow preserved shortening at the endocardium despite depressed LV midwall circumferential shortening (MWCS). Depressed MWCS is an adverse prognostic indicator, but whether this finding reflects reduced global or regional LV myocardial function, as assessed by three-dimensional (3D) myocardial strain, is unknown. Methods and Results: Cardiac Magnetic Resonance (CMR) tissue tagging permits direct evaluation of regional 3D intramyocardial strain, independent of LV geometry. We evaluated 21 hypertensive patients with electrocardiographic LVH in the LIFE study and 8 normal controls using 3D MR tagging and echocardiography. Patients had higher MR LV mass than normals (116 ± 40 versus 63 ± 6 g/m2, P = 0.002). Neither echocardiographic fractional shortening (32 ± 6 versus 33% ± 3%), LVEF (63% versus 64%) or mean end-systolic stress (175 ± 27 versus 146 ± 28 g/cm2) were significantly different, yet global MWCS was decreased by both echocardiography (13.4 ± 2.8 versus 18.2% ± 1.5%, P P P = 0.002) in LVH and greater in lateral and anterior regions versus septal and posterior regions ( P P P 0.60, P = 0.001 for both). Conclusions: In patients with hypertensive LVH, despite normal LV function via echocardiography or CMR, CMR intramyocardial tagging show depressed global MWCS while 3D MR strain revealed marked underlying regional heterogeneity of LV dysfunction.展开更多
Many studies have shown that bio-scaffolds have important value for promoting axonal regeneration of injured spinal cord.Indeed,cell transplantation and bio-scaffold implantation are considered to be effective methods...Many studies have shown that bio-scaffolds have important value for promoting axonal regeneration of injured spinal cord.Indeed,cell transplantation and bio-scaffold implantation are considered to be effective methods for neural regeneration.This study was designed to fabricate a type of three-dimensional collagen/silk fibroin scaffold (3D-CF) with cavities that simulate the anatomy of normal spinal cord.This scaffold allows cell growth in vitro and in vivo.To observe the effects of combined transplantation of neural stem cells (NSCs) and 3D-CF on the repair of spinal cord injury.Forty Sprague-Dawley rats were divided into four groups: sham (only laminectomy was performed),spinal cord injury (transection injury of T10 spinal cord without any transplantation),3D-CF (3D scaffold was transplanted into the local injured cavity),and 3D-CF + NSCs (3D scaffold co-cultured with NSCs was transplanted into the local injured cavity.Neuroelectrophysiology,imaging,hematoxylin-eosin staining,argentaffin staining,immunofluorescence staining,and western blot assay were performed.Apart from the sham group,neurological scores were significantly higher in the 3D-CF + NSCs group compared with other groups.Moreover,latency of the 3D-CF + NSCs group was significantly reduced,while the amplitude was significantly increased in motor evoked potential tests.The results of magnetic resonance imaging and diffusion tensor imaging showed that both spinal cord continuity and the filling of injury cavity were the best in the 3D-CF + NSCs group.Moreover,regenerative axons were abundant and glial scarring was reduced in the 3D-CF + NSCs group compared with other groups.These results confirm that implantation of 3D-CF combined with NSCs can promote the repair of injured spinal cord.This study was approved by the Institutional Animal Care and Use Committee of People’s Armed Police Force Medical Center in 2017 (approval No.2017-0007.2).展开更多
Modern post-mortem investigations use an increasing number of digital imaging methods,which can be collected under the term“post-mortem imaging”.Most methods of forensic imaging are from the radiology field and are ...Modern post-mortem investigations use an increasing number of digital imaging methods,which can be collected under the term“post-mortem imaging”.Most methods of forensic imaging are from the radiology field and are therefore techniques that show the interior of the body with technologies such as X-ray or magnetic resonance imaging.To digitally image the surface of the body,other techniques are regularly applied,e.g.three-dimensional(3D)surface scanning(3DSS)or photogrammetry.Today’s most frequently used techniques include post-mortem computed tomography(PMCT),post-mortem magnetic resonance imaging(PMMR),post-mortem computed tomographic angiography(PMCTA)and 3DSS or photogrammetry.Each of these methods has specific advantages and limitations.Therefore,the indications for using each method are different.While PMCT gives a rapid overview of the interior of the body and depicts the skeletal system and radiopaque foreign bodies,PMMR allows investigation of soft tissues and parenchymal organs.PMCTA is the method of choice for viewing the vascular system and detecting sources of bleeding.However,none of those radiological methods allow a detailed digital view of the body’s surface,which makes 3DSS the best choice for such a purpose.If 3D surface scanners are not available,photogrammetry is an alternative.This review article gives an overview of different imaging techniques and explains their applications,advantages and limitations.We hope it will improve understanding of the methods.展开更多
The on-board methanol steam reforming(MSR) has long been considered as an effective approach to insitu produce hydrogen for fuel cell vehicles(FCVs). However, the conventional MSR catalyst pellets suffer from easy bre...The on-board methanol steam reforming(MSR) has long been considered as an effective approach to insitu produce hydrogen for fuel cell vehicles(FCVs). However, the conventional MSR catalyst pellets suffer from easy breakage during the vehicle movement, leading to increased pressure drop and reduced system stability. Herein, we introduce an integrated method to prepare the highly controlled structured catalysts based on coupled processes: direct prototyping the structured substrate using digital light processing(DLP) 3D printing technology, in-situ dynamic crystallization of active components assisted by magnetic resonance imaging(MRI) and calcination. The synthesized catalyst owns a gradient layer of active component, and exhibits better MSR performance, higher mechanical strength, reduced pressure drop, higher Cu dispersion and better adhesion of active compounds when compared with the conventional powder and pellet catalysts. The demonstrated successful application proves the feasibility of developed method,which has great potential to be used for preparing precisely other monolithic catalysts with customized structures.展开更多
Objectives: The overall aim is to propose a general framework to build any kind of interactive digital atlas. It can be used either as pedagogical support to study human anatomy or as a tool to aid health professional...Objectives: The overall aim is to propose a general framework to build any kind of interactive digital atlas. It can be used either as pedagogical support to study human anatomy or as a tool to aid health professionals improving the quality of the human resources formation. Methods: To illustrate the use of the proposed methodology was build an atlas of intracranial human anatomy. We used 3D surface rendering techniques to create a brain atlas that would allow us to correlate bi-dimensional MRI images with 3D brain structures. Results: The system was coded in Java and distributed under GNU/GLP license, making it available to use and/or to expand and serve as an educational tool allow medical students to use it to evaluate the special relationships among structures. Conclusions: The characteristics of the obtained Atlas are essential in the Brazilian public health context, where professionals in several different geographical locations (submitted to distinct informatics infrastructure) need to be trained.展开更多
In situ monitoring of bone regeneration enables timely diagnosis and intervention by acquiring vital biological parameters.However,an existing gap exists in the availability of effective methodologies for continuous a...In situ monitoring of bone regeneration enables timely diagnosis and intervention by acquiring vital biological parameters.However,an existing gap exists in the availability of effective methodologies for continuous and dynamic monitoring of the bone tissue regeneration process,encompassing the concurrent visualization of bone formation and implant degradation.Here,we present an integrated scaffold designed to facilitate real-time monitoring of both bone formation and implant degradation during the repair of bone defects.Laponite(Lap),CyP-loaded mesoporous silica(CyP@MSNs)and ultrasmall superparamagnetic iron oxide nanoparticles(USPIO@SiO2)were incorporated into a bioink containing bone marrow mesenchymal stem cells(BMSCs)to fabricate functional scaffolds denoted as C@M/GLU using 3D bioprinting technology.In both in vivo and in vitro experiments,the composite scaffold has demonstrated a significant enhancement of bone regeneration through the controlled release of silicon(Si)and magnesium(Mg)ions.Employing near-infrared fluorescence(NIR-FL)imaging,the composite scaffold facilitates the monitoring of alkaline phosphate(ALP)expression,providing an accurate reflection of the scaffold’s initial osteogenic activity.Meanwhile,the degradation of scaffolds was monitored by tracking the changes in the magnetic resonance(MR)signals at various time points.These findings indicate that the designed scaffold holds potential as an in situ bone implant for combined visualization of osteogenesis and implant degradation throughout the bone repair process.展开更多
文摘Femoroacetabular impingement is uncommonly associated with a large rim fragment of bone along the superolateral acetabulum. We report an unusual case of femoroacetabular impingement(FAI) with chronic acetabular rim fracture. Radiographic, 3D computed tomography, 3D magnetic resonance imaging and arthroscopy correlation is presented with discussion of relative advantages and disadvantages of various modalities in the context of FAI.
文摘An infant male presented with the rare anatomy consisting of situs solitus,concordant atrioventricular connections to L-looped ventricles,double outlet right ventricle(DORV),and hypoplastic aortic arch.6 months after neonatal aortic arch repair,the morphologic right ventricle function deteriorated,and surgical evaluation was undertaken to determine if either biventricular repair with a systemic morphologic left ventricle or right ventricular exclusion was possible.After initial echocardiography,magnetic resonance imaging(MRI)was used to create detailed axial and 4-dimensional(4D)images and 3-dimensional(3D)printed models.The detailed anatomy of this rare,complex case and its use in pre-surgical planning is presented.
文摘This study is to compare three-dimensional(3D)isotropic T2-weighted magnetic resonance imaging(MRI)with compressed sensing-sampling perfection with application optimized contrast(CS-SPACE)and the conventional image(3D-SPACE)sequence in terms of image quality,estimated signal-to-noise ratio(SNR),relative contrast-to-noise ratio(CNR),and the lesions’conspicuous of the female pelvis.Thirty-six females(age:51,28-73)with cervical carcinoma(n=20),rectal carcinoma(n=7),or uterine fibroid(n=9)were included.Patients underwent magnetic resonance(MR)imaging at a 3T scanner with the sequences of 3D-SPACE,CS-SPACE,and twodimensional(2D)T2-weighted turbo-spin echo(TSE).Quantitative analyses of estimated SNR and relative CNR between tumors and other tissues,image quality,and tissue conspicuity were performed.Two radiologists assessed the difference in diagnostic findings for carcinoma.Quantitative values and qualitative scores were analyzed,respectively.The estimated SNR and the relative CNR of tumor-to-muscle obturator internus,tumor-to-myometrium,and myometrium-to-muscle obturator internus was comparable between 3D-SPACE and CS-SPACE.The overall image quality and the conspicuity of the lesion scores of the CS-SPACE were higher than that of the 3D-SPACE(P<0.01).The CS-SPACE sequence offers shorter scan time,fewer artifacts,and comparable SNR and CNR to conventional 3D-SPACE,and has the potential to improve the performance of T2-weighted images.
基金Supported by NIDA,No.K23DA045928-01(to Bachi K) and No.R01DA041528(to Goldstein RZ)NIH/NHLBI,No.R01HL071021+1 种基金Translational and Molecular Imaging Institute internal funding(to Fayad ZAF)American Heart Association Grant in Aid,No.17GRNT33420119(to Mani VM)
文摘BACKGROUND Chronic cocaine use is associated with stroke, coronary artery disease and myocardial infarction, resulting in severe impairments or sudden mortality. In the absence of clear cardiovascular symptoms, individuals with cocaine use disorder (iCUD) seeking addiction treatment receive mostly psychotherapy and psychiatric pharmacotherapy, with no attention to vascular disease (i.e., atherosclerosis). Little is known about the pre-clinical signs of cardiovascular risk in iCUD and early signs of vascular disease are undetected in this underserved population. AIM To assess inflammation, plaque burden and plaque composition in iCUD aiming to detect markers of atherosclerosis and vascular disease. METHODS The bilateral carotid arteries were imaged with positron emission tomography/magnetic resonance imaging (PET/MRI) in iCUD asymptomatic for cardiovascular disease, healthy controls, and individuals with cardiovascular risk. PET with 18F-fluorodeoxyglucose (18F-FDG) evaluated vascular inflammation and 3-D dark-blood MRI assessed plaque burden including wall area and thickness. Drug use and severity of addiction were assessed with standardized instruments. RESULTS The majority of iCUD and controls had carotid FDG-PET signal greater than 1.6 but lower than 3, indicating the presence of mild to moderate inflammation. However, the MRI measure of wall structure was thicker in iCUD as compared to the controls and cardiovascular risk group, indicating greater carotid plaque burden. iCUD had larger wall area as compared to the healthy controls but not as compared to the cardiovascular risk group, indicating structural wall similarities between the non-control study groups. In iCUD, wall area correlated with greater cocaine withdrawal and craving. CONCLUSION These preliminary results show markers of carotid artery disease burden in cardiovascular disease-asymptomatic iCUD. Broader trials are warranted to develop protocols for early detection of cardiovascular risk and preventive intervention in iCUD.
文摘BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is important.AIM To investigate the diagnostic value of magnetic resonance multi-delay threedimensional arterial spin labeling(3DASL)and diffusion kurtosis imaging(DKI)in evaluating the perfusion and infarct area size in patients with acute cerebral ischemia.METHODS Eighty-four patients who experienced acute cerebral ischemia from March 2019 to February 2021 were included.All patients in the acute stage underwent magnetic resonance-based examination,and the data were processed by the system’s own software.The apparent diffusion coefficient(ADC),average diffusion coefficient(MD),axial diffusion(AD),radial diffusion(RD),average kurtosis(MK),radial kurtosis(fairly RK),axial kurtosis(AK),and perfusion parameters post-labeling delays(PLD)in the focal area and its corresponding area were compared.The correlation between the lesion area of cerebral infarction under MK and MD and T2-weighted imaging(T2WI)was analyzed.RESULTS The DKI parameters of focal and control areas in the study subjects were compared.The ADC,MD,AD,and RD values in the lesion area were significantly lower than those in the control area.The MK,RK,and AK values in the lesion area were significantly higher than those in the control area.The MK/MD value in the infarct lesions was used to determine the matching situation.MK/MD<5 mm was considered matching and MK/MD≥5 mm was considered mismatching.PLD1.5s and PLD2.5s perfusion parameters in the central,peripheral,and control areas of the infarct lesions in MK/MD-matched and-unmatched patients were not significantly different.PLD1.5s and PLD2.5s perfusion parameter values in the central area of the infarct lesions in MK/MD-matched and-unmatched patients were significantly lower than those in peripheral and control areas.The MK and MD maps showed a lesion area of 20.08±5.74 cm^(2) and 22.09±5.58 cm^(2),respectively.T2WI showed a lesion area of 19.76±5.02 cm^(2).There were no significant differences in the cerebral infarction lesion areas measured using the three methods.MK,MD,and T2WI showed a good correlation.CONCLUSION DKI parameters showed significant difference between the focal and control areas in patients with acute ischemic cerebral infarction.3DASL can effectively determine the changes in perfusion levels in the lesion area.There was a high correlation between the area of the infarct lesions diagnosed by DKI and T2WI.
文摘目的探讨Radial 3D VIBE在儿童自由呼吸下腹部平扫获得T1加权图像的临床应用。方法选取我院2015年1月~2015年8月行腹部磁共振检查患者100例,T1加权图像均采用常规梯度回波序列和Radial 3D VIBE序列分别扫描。结果对两种扫描序列定性分析,结果表明Radial 3D VIBE序列得的信噪比和对比噪声比均显著高于常规序列,图像质量明显提高,能够清晰显示病变部位。与常规序列相比,Radial 3D VIBE序列出现呼吸运动伪影显著低于常规序列,P<0.05。结论 Radial 3D VIBE序列可提高磁共振成像分辨率,有效减少呼吸运动伪影,提高图像质量。
文摘Background: Increased relative wall thickness in hypertensive left ventricular hypertrophy (LVH) has been shown by echocardiography to allow preserved shortening at the endocardium despite depressed LV midwall circumferential shortening (MWCS). Depressed MWCS is an adverse prognostic indicator, but whether this finding reflects reduced global or regional LV myocardial function, as assessed by three-dimensional (3D) myocardial strain, is unknown. Methods and Results: Cardiac Magnetic Resonance (CMR) tissue tagging permits direct evaluation of regional 3D intramyocardial strain, independent of LV geometry. We evaluated 21 hypertensive patients with electrocardiographic LVH in the LIFE study and 8 normal controls using 3D MR tagging and echocardiography. Patients had higher MR LV mass than normals (116 ± 40 versus 63 ± 6 g/m2, P = 0.002). Neither echocardiographic fractional shortening (32 ± 6 versus 33% ± 3%), LVEF (63% versus 64%) or mean end-systolic stress (175 ± 27 versus 146 ± 28 g/cm2) were significantly different, yet global MWCS was decreased by both echocardiography (13.4 ± 2.8 versus 18.2% ± 1.5%, P P P = 0.002) in LVH and greater in lateral and anterior regions versus septal and posterior regions ( P P P 0.60, P = 0.001 for both). Conclusions: In patients with hypertensive LVH, despite normal LV function via echocardiography or CMR, CMR intramyocardial tagging show depressed global MWCS while 3D MR strain revealed marked underlying regional heterogeneity of LV dysfunction.
文摘目的通过常规技术和Blade技术检查眼眶疾病患者图像信噪比,探讨Blade技术对伪影发生、影像质量的改善情况。方法选取2012-07至2013-06行眼眶磁共振扫描的患者,并且行常规眼眶Tse T2WI序列扫描时显现不同程度的不自主运动伪影,最终纳入136例。采用德国西门子公司Trio Tim 3.0T超导磁共振成像系统,以在相同位置对所有患者先后进行常规磁共振扫描和Blade技术扫描,并以常规磁共振扫描图像的图像质量分级,将136例分为轻度、中度和重度伪影组,获取不同组两种扫描图像的信噪比,从而评价Blade技术对图像质量的改善情况。结果轻度伪影组眼球区(t=4.159,P<0.05)和骨膜外区(t=-4.306,P<0.05)Blade技术信噪比明显高于常规技术;中度伪影组各眼眶分区内Blade技术信噪比与常规技术比较无统计学差异;重度伪影组眼球区(t=-4.917,P<0.05)、视神经鞘区(Z=-4.687,P<0.05)和骨膜外区(Z=-3.431,P<0.05)Blade技术信噪比明显高于常规技术。结论 Blade技术可提高眼眶扫描中图像的信噪比,且在同一伪影程度组中不同眼眶分区的信噪比差异有区别。
基金supported by the National Natural Science Foundation of China,No.11672332(to XYC)the National Key Research and Development Plan of China,No.2016YFC1101500(to SZ)
文摘Many studies have shown that bio-scaffolds have important value for promoting axonal regeneration of injured spinal cord.Indeed,cell transplantation and bio-scaffold implantation are considered to be effective methods for neural regeneration.This study was designed to fabricate a type of three-dimensional collagen/silk fibroin scaffold (3D-CF) with cavities that simulate the anatomy of normal spinal cord.This scaffold allows cell growth in vitro and in vivo.To observe the effects of combined transplantation of neural stem cells (NSCs) and 3D-CF on the repair of spinal cord injury.Forty Sprague-Dawley rats were divided into four groups: sham (only laminectomy was performed),spinal cord injury (transection injury of T10 spinal cord without any transplantation),3D-CF (3D scaffold was transplanted into the local injured cavity),and 3D-CF + NSCs (3D scaffold co-cultured with NSCs was transplanted into the local injured cavity.Neuroelectrophysiology,imaging,hematoxylin-eosin staining,argentaffin staining,immunofluorescence staining,and western blot assay were performed.Apart from the sham group,neurological scores were significantly higher in the 3D-CF + NSCs group compared with other groups.Moreover,latency of the 3D-CF + NSCs group was significantly reduced,while the amplitude was significantly increased in motor evoked potential tests.The results of magnetic resonance imaging and diffusion tensor imaging showed that both spinal cord continuity and the filling of injury cavity were the best in the 3D-CF + NSCs group.Moreover,regenerative axons were abundant and glial scarring was reduced in the 3D-CF + NSCs group compared with other groups.These results confirm that implantation of 3D-CF combined with NSCs can promote the repair of injured spinal cord.This study was approved by the Institutional Animal Care and Use Committee of People’s Armed Police Force Medical Center in 2017 (approval No.2017-0007.2).
文摘Modern post-mortem investigations use an increasing number of digital imaging methods,which can be collected under the term“post-mortem imaging”.Most methods of forensic imaging are from the radiology field and are therefore techniques that show the interior of the body with technologies such as X-ray or magnetic resonance imaging.To digitally image the surface of the body,other techniques are regularly applied,e.g.three-dimensional(3D)surface scanning(3DSS)or photogrammetry.Today’s most frequently used techniques include post-mortem computed tomography(PMCT),post-mortem magnetic resonance imaging(PMMR),post-mortem computed tomographic angiography(PMCTA)and 3DSS or photogrammetry.Each of these methods has specific advantages and limitations.Therefore,the indications for using each method are different.While PMCT gives a rapid overview of the interior of the body and depicts the skeletal system and radiopaque foreign bodies,PMMR allows investigation of soft tissues and parenchymal organs.PMCTA is the method of choice for viewing the vascular system and detecting sources of bleeding.However,none of those radiological methods allow a detailed digital view of the body’s surface,which makes 3DSS the best choice for such a purpose.If 3D surface scanners are not available,photogrammetry is an alternative.This review article gives an overview of different imaging techniques and explains their applications,advantages and limitations.We hope it will improve understanding of the methods.
基金supported by the Youth Innovation Promotion Association of Chinese Academy of Sciencesthe Key Technical Personnel of Chinese Academy of Sciences+1 种基金the STS Program of Chinese Academy of Sciences (No. KFJJ-STS-SCYD-302)the National Natural Science Foundation of China (22108288)。
文摘The on-board methanol steam reforming(MSR) has long been considered as an effective approach to insitu produce hydrogen for fuel cell vehicles(FCVs). However, the conventional MSR catalyst pellets suffer from easy breakage during the vehicle movement, leading to increased pressure drop and reduced system stability. Herein, we introduce an integrated method to prepare the highly controlled structured catalysts based on coupled processes: direct prototyping the structured substrate using digital light processing(DLP) 3D printing technology, in-situ dynamic crystallization of active components assisted by magnetic resonance imaging(MRI) and calcination. The synthesized catalyst owns a gradient layer of active component, and exhibits better MSR performance, higher mechanical strength, reduced pressure drop, higher Cu dispersion and better adhesion of active compounds when compared with the conventional powder and pellet catalysts. The demonstrated successful application proves the feasibility of developed method,which has great potential to be used for preparing precisely other monolithic catalysts with customized structures.
文摘Objectives: The overall aim is to propose a general framework to build any kind of interactive digital atlas. It can be used either as pedagogical support to study human anatomy or as a tool to aid health professionals improving the quality of the human resources formation. Methods: To illustrate the use of the proposed methodology was build an atlas of intracranial human anatomy. We used 3D surface rendering techniques to create a brain atlas that would allow us to correlate bi-dimensional MRI images with 3D brain structures. Results: The system was coded in Java and distributed under GNU/GLP license, making it available to use and/or to expand and serve as an educational tool allow medical students to use it to evaluate the special relationships among structures. Conclusions: The characteristics of the obtained Atlas are essential in the Brazilian public health context, where professionals in several different geographical locations (submitted to distinct informatics infrastructure) need to be trained.
基金support from various resources,including the National Natural Science Foundation of China (grant numbers 32071350,32271412,32171404)the Shanghai Rising-Star Program (grant numbers 22QA1400100)+1 种基金the Fundamental Research Funds for the Central Universities (grant numbers 2232019A3-06,2232021D-10)the Science and Technology Commission of Shanghai Municipality (grant numbers 21ZR1403100,19440741600,20DZ2254900).
文摘In situ monitoring of bone regeneration enables timely diagnosis and intervention by acquiring vital biological parameters.However,an existing gap exists in the availability of effective methodologies for continuous and dynamic monitoring of the bone tissue regeneration process,encompassing the concurrent visualization of bone formation and implant degradation.Here,we present an integrated scaffold designed to facilitate real-time monitoring of both bone formation and implant degradation during the repair of bone defects.Laponite(Lap),CyP-loaded mesoporous silica(CyP@MSNs)and ultrasmall superparamagnetic iron oxide nanoparticles(USPIO@SiO2)were incorporated into a bioink containing bone marrow mesenchymal stem cells(BMSCs)to fabricate functional scaffolds denoted as C@M/GLU using 3D bioprinting technology.In both in vivo and in vitro experiments,the composite scaffold has demonstrated a significant enhancement of bone regeneration through the controlled release of silicon(Si)and magnesium(Mg)ions.Employing near-infrared fluorescence(NIR-FL)imaging,the composite scaffold facilitates the monitoring of alkaline phosphate(ALP)expression,providing an accurate reflection of the scaffold’s initial osteogenic activity.Meanwhile,the degradation of scaffolds was monitored by tracking the changes in the magnetic resonance(MR)signals at various time points.These findings indicate that the designed scaffold holds potential as an in situ bone implant for combined visualization of osteogenesis and implant degradation throughout the bone repair process.
