To investigate the relationship between spontaneous echo contrast (SEC) and left atrial appendage (LAA) blood flow velocity using transesophageal echocardiography (TEE) during percutaneous balloon mitral valvotomy (PB...To investigate the relationship between spontaneous echo contrast (SEC) and left atrial appendage (LAA) blood flow velocity using transesophageal echocardiography (TEE) during percutaneous balloon mitral valvotomy (PBMV) in patients with atrial fibrillation and sinus rhythm Methods Thirty five patients (21 in sinus rhythm and 14 in atrial fibrillation ) with rheumatic mitral stenosis underwent PBMV with intraoperative transesophageal echocardiography monitoring We measured LAA blood flow velocities and observed the left atrium for various grades of SEC (from 0=none to 4=severe), before and after each balloon inflation Results Left atrial appendage maximal emptying velocity (LAA MEV) was reduced from 35±14?cm/s to 6±2?cm/s at peak balloon inflation and increased to 40±16?cm/s after balloon deflation Comparison of the values before balloon inflation and after balloon deflation showed that LAA velocities were significantly lower (P<0 001) During balloon inflation, both maximal emptying velocity (MEV) and maximal filling velocity (MFV) were significantly decreased, compared to those before inflation and after balloon deflation (P<0 01) And both MEV and MFV were significantly higher after balloon deflation relative to those before balloon inflation Patients with atrial fibrillation had significantly lower MEV and MFV before and during balloon inflation and after balloon deflation than patients with sinus rhythm At peak balloon inflation, new or increased SEC grades were observed during 54 of 61 (88%) inflations and unchanged during 7 (12%) inflations SEC grades were reduced after 55 balloon deflations (90%), completely disappeared after 18 deflations (30%) and remained unchanged after 6 deflations (10%) At peak balloon inflation,left atrium spontaneous echo contrast (LASEC) grade 4 was observed during 14 of 27 (93%) inflations in the atrial fibrillation patients, significantly higher than in patients with sinus rhythm (8 of 34, 24%; P <0 05) LASEC completely disappeared after 16 of 34 deflations (47%) in the patients with sinus rhythm, significantly higher than in the atrial fibrillation patients (2 of 27 deflations; P <0 01) The mean time to achieve maximal SEC grade (2 5±1 2?s) correlated with the mean time to trough LAA velocities (2 3±1 1?s ) after balloon inflation Both the time to lowest LAA velocity and the time to highest LASEC were significantly longer in the patients with sinus rhythm than in the atrial fibrillation patients (2 6±1 1?s vs 1 7±1 0?s, P<0 05 and 2 8±1 4?s vs 1 9±1 3?s, P<0 05, respectively) Upon deflation, the mean time to lowest SEC grade (2 9±1 8?s) correlated with the mean time to achieve maximal LAA velocities (2 7±1 6?s) Both intervals are significantly shorter in the patients with sinus rhythm than in the atrial fibrillation patients (2 0±1 6?s vs 3 5±1 5?s, P<0 01 and 2 2±1 7?s vs 3 6± 1 6?s, P<0 05) Conclusion Reducing the blood flow velocity in the human left atrium by balloon occlusion of the mitral valve may enhance SEC, whereas restoring blood flow after balloon deflation would cause enhanced echogenic blood to disappear or decrease in both groups of patients Patients with atrial fibrillation demonstrate more severe blood stagnation of the left atrial body and appendage during transient balloon inflation at mitral valve orifice and slower recovery from the stagnation, decreasing to a lesser extent after balloon deflation, when compared to patients with sinus rhythm展开更多
AIM: To characterize the effects of iodinated contrast material(ICM) on magnetic resonance imaging(MRI) comparing different sequences and magnetic fields, with emphasis to similarities/differences with well-known sign...AIM: To characterize the effects of iodinated contrast material(ICM) on magnetic resonance imaging(MRI) comparing different sequences and magnetic fields, with emphasis to similarities/differences with well-known signal characteristics of hemorrhage in the brain. METHODS: Aliquots of iopamidol and iodixanol mixed with normal saline were scanned at 1.5T and 3T. Signal intensity(SI) was measured using similar spin-echo(SE)-T1, SE-T2, gradient-echo(GRE) and fluid-attenuationinversion-recovery(FLAIR) sequences at both magnets. Contrast to noise ratio(CNR)(SI contrast-SI saline/SD noise) for each aliquot were calculated and Kruskall-wallis test and graphic analysis was used to compare different pulse sequences and ICMs. RESULTS: Both ICM showed increased SI on SE-T1 and decreased SI on SE-T2, GRE and FLAIR at both 1.5T and 3T, as the concentration was increased. By CNR measurements, SE-T2 had the greatest conspicuity at 3T with undiluted iopamidol(92.6 ± 0.3, P < 0.00) followed by iodixanol(77.5 ± 0.9, P < 0.00) as compared with other sequences(CNR range: 15-40). While SE-T2 had greatest conspicuity at 1.5T with iopamidol(49.3 ± 1, P < 0.01), SE-T1 showed similar or slightly better conspicuity(20.8 ± 4) than SE-T2 with iodixanol(23 ± 1.7). In all cases, hypo-intensity on GRE was less conspicuous than on SE-T2.CONCLUSION: Iodixanol and iopamidol shorten T1 and T2 relaxation times at both 1.5T and 3T. Hypo-intensity due to shortened T2 relaxation time is significantly more conspicuous than signal changes on T1-WI, FLAIR or GRE. Variations in signal conspicuity according to pulse sequence and to type of ICM are exaggerated at 3T. We postulate T2 hypointensity with less GRE conspicuity differentiates ICM from hemorrhage; given the wellknown GRE hypointensity of hemorrhage. Described signal changes may be relevant in the setting of recent intra-arterial or intravenous ICM administration in translational research and/or human stroke therapy.展开更多
Purpose: To optimize contrast to noise ratio (CNR) in magnetic resonance imaging (MRI) of prostate cancer using at 3T. Methods: CNR was expressed as a difference in MR signals of two samples. Amulti-echo spin-echo (ME...Purpose: To optimize contrast to noise ratio (CNR) in magnetic resonance imaging (MRI) of prostate cancer using at 3T. Methods: CNR was expressed as a difference in MR signals of two samples. Amulti-echo spin-echo (MESE) pulse sequence was used. The theoretical value of the maximum CNR was obtained using the derivative of CNR with echo time (TE) as a variable. The T<sub>1</sub> relaxation time was ignored as repetition time (TR) was assumed to be very long (TR >> T<sub>1</sub>). The theoretical calculations were confirmed with in vitro and in vivo experiments. For in vitro experiments we used samples with different T<sub>2</sub> values using various concentrations of super paramagnetic iron oxide (SPIO) and for in vivo experiments we used an animal model of prostate cancer. Results: CNR was maximized by selecting the optimum TE for a multi-echo spin-echo (MESE) pulse sequence based on theoretical predictions. MR images of prostate cancer at 3T were obtained and showed maximum CNR at the predicted TE. Conclusions: It was possible to maximize CNR of prostate tumour by selecting the optimal TE based on simple theoretical calculations. The proposed method can be applied to other pulse sequences and tissues. It can be applied to any MRI system at any magnetic field. However the method requires knowledge of T<sub>2</sub> relaxation times.展开更多
目的:评估基于深度学习重建的半傅立叶采集单次激发快速自旋回波(HASTEDL)序列在肝脏检查中的应用价值。方法:使用3.0T MR对36例患者(男28例,女8例)行上腹部MRI扫描,扫描序列包括单次屏气HASTEDL和多次屏气刀锋伪影校正(BLADE)序列。由...目的:评估基于深度学习重建的半傅立叶采集单次激发快速自旋回波(HASTEDL)序列在肝脏检查中的应用价值。方法:使用3.0T MR对36例患者(男28例,女8例)行上腹部MRI扫描,扫描序列包括单次屏气HASTEDL和多次屏气刀锋伪影校正(BLADE)序列。由两位医师分别对肝脏成像质量(锐利度和伪影)进行五分制主观评分。分别在肝门水平肝脏的肝右叶和肝左叶、病灶显示最大层面及其相应层面同一相位方向的右侧背景区放置感兴趣区,测量两组图像上肝脏的信号强度(SI)及其标准差(SD,作为背景噪声),计算图像的信噪比(SNR)和对比噪声比(CNR)。测量病灶最大径(Dmax),观察和记录图像错层率及病灶检出率。对两组图像上肝右叶和肝左叶内肝实质的SNR、CNR,病灶的SNR、CNR、D值,以及图像错层率、图像质量评分结果分别使用Wilcoxon检验或卡方检验进行组间比较。结果:两位医师对两组图像(HASTEDL和BLADE序列)的主观评分和客观测量数据的一致性均为良好(Kappa和ICC值均大于0.75)。两组之间图像锐利度主观评分的差异无统计学意义(4.62±0.55 vs. 4.27±0.65,P=0.289),HASTE-DL组图像伪影的主观评分显著高于BLADE组(4.78±0.48 vs. 4.14±0.98,P<0.001)。HASTEDL组肝左叶和肝右叶内肝组织的SNR、病灶的SNR和CNR均显著高于BLADE组(P<0.001)。两组之间病灶Dmax的差异无统计学意义(P=0.978)。BLADE组的图像错层率明显高于HASTEDL组(P=0.014)。两组中病灶检出率均为100%。结论:基于深度学习重建的单次屏气HASTE序列能有效提高肝脏T2WI图像质量而不会遗漏病灶,并可显著缩短扫描时间,优化肝脏扫描效率,有较好的临床应用前景。展开更多
Contrast echocardiography with left ventricular opacification （LVO） improves the definition of endocardium in two-dimensional echocardiography （2DE）. This study was aimed to determine whether LVO offered added dia...Contrast echocardiography with left ventricular opacification （LVO） improves the definition of endocardium in two-dimensional echocardiography （2DE）. This study was aimed to determine whether LVO offered added diagnostic value in noncompaetion of left ventricular myocardium （NCVM）. A total of 85 patients （40± 20 years, 54 males） with suspected NCVM were subjected to transthoracic 2DE and LVO, and 40 healthy volunteers were examined with 2DE and assigned as control subjects. The location of NCVM, the thickness ratio of noncompacted to compacted myocardium （NCR）, and the cavity size and ejection fraction of LV were quantified. Results revealed that NCVM was mainly located in the LV medium （53.2%）, apical （46.2%） segments, and lateral wall （39.8%）. The NCR obtained through LVO was greater than that detected through 2DE （4.2 ±1.3 vs. 3.3 ±1.2, P 〈 0.001）, and higher inter-correlations and less intra- and inter-observer variabilities were determined in the former than in the latter. The NCVM detection rates were also increased from 63.5% via 2DE to 83.5% via LVO and 89.4% via 2DE combined with LVO （2DE ＋ LVO） （P = 0.0004）. The LV cavity size was greater and the LV ejection fraction （LVEF） was lower in the NCVM patients than in the control group （P 〈 0.01）. In the NCVM group, the LV cavity size was higher and the LVEF was lower in LVO than in 2DE （P 〈 0.01）. In conclusion, contrast echocardiography contributes significant sensitivity and reproducibility to routine transthoraeic echoeardiography in NCVM diagnosis. Therefore, this technique should be clinically performed to diagnose suspected NCVM.展开更多
基金We appreciated Xuan Jiang for the statistical analysis. This work was supported by National Nature Science Foundation of China （No.81370295）, Science and Technology Program of Guangdong Province, China （No. 2017A02 0215054）, Science and Technology Planning of Guangzhou City, China （No.2014B070705005）. The authors declared no potential conflicts of interest with respect to the research, authorship or publication of this article.
文摘ObjectiveTo 在左 atrial 血栓( LAT )或左 atrial 上评估红房间分发宽度( RDW )的预兆的价值在有纤维性颤动( AF ) .MethodsWe 考察了的非瓣膜的 atrial 的病人的自发的回响对比( LASEC )作为非瓣膜的 AF 被诊断并且经历了 transesophageal echocardiography ( T )在里面的 692 个病人从2014年4月的广东心血管的研究所到2015年12月。基线临床的特征，血常规的实验室测试，心动电流描记器大小是 analyzed.ResultsEighty -- 四个病人在 T 下面与 LAT/LASEC 被检查。吝啬的 RDW 水平与 non-LAT/LASEC 病人相比在 LAT/LASEC 病人是显著地更高的(13.59%
文摘To investigate the relationship between spontaneous echo contrast (SEC) and left atrial appendage (LAA) blood flow velocity using transesophageal echocardiography (TEE) during percutaneous balloon mitral valvotomy (PBMV) in patients with atrial fibrillation and sinus rhythm Methods Thirty five patients (21 in sinus rhythm and 14 in atrial fibrillation ) with rheumatic mitral stenosis underwent PBMV with intraoperative transesophageal echocardiography monitoring We measured LAA blood flow velocities and observed the left atrium for various grades of SEC (from 0=none to 4=severe), before and after each balloon inflation Results Left atrial appendage maximal emptying velocity (LAA MEV) was reduced from 35±14?cm/s to 6±2?cm/s at peak balloon inflation and increased to 40±16?cm/s after balloon deflation Comparison of the values before balloon inflation and after balloon deflation showed that LAA velocities were significantly lower (P<0 001) During balloon inflation, both maximal emptying velocity (MEV) and maximal filling velocity (MFV) were significantly decreased, compared to those before inflation and after balloon deflation (P<0 01) And both MEV and MFV were significantly higher after balloon deflation relative to those before balloon inflation Patients with atrial fibrillation had significantly lower MEV and MFV before and during balloon inflation and after balloon deflation than patients with sinus rhythm At peak balloon inflation, new or increased SEC grades were observed during 54 of 61 (88%) inflations and unchanged during 7 (12%) inflations SEC grades were reduced after 55 balloon deflations (90%), completely disappeared after 18 deflations (30%) and remained unchanged after 6 deflations (10%) At peak balloon inflation,left atrium spontaneous echo contrast (LASEC) grade 4 was observed during 14 of 27 (93%) inflations in the atrial fibrillation patients, significantly higher than in patients with sinus rhythm (8 of 34, 24%; P <0 05) LASEC completely disappeared after 16 of 34 deflations (47%) in the patients with sinus rhythm, significantly higher than in the atrial fibrillation patients (2 of 27 deflations; P <0 01) The mean time to achieve maximal SEC grade (2 5±1 2?s) correlated with the mean time to trough LAA velocities (2 3±1 1?s ) after balloon inflation Both the time to lowest LAA velocity and the time to highest LASEC were significantly longer in the patients with sinus rhythm than in the atrial fibrillation patients (2 6±1 1?s vs 1 7±1 0?s, P<0 05 and 2 8±1 4?s vs 1 9±1 3?s, P<0 05, respectively) Upon deflation, the mean time to lowest SEC grade (2 9±1 8?s) correlated with the mean time to achieve maximal LAA velocities (2 7±1 6?s) Both intervals are significantly shorter in the patients with sinus rhythm than in the atrial fibrillation patients (2 0±1 6?s vs 3 5±1 5?s, P<0 01 and 2 2±1 7?s vs 3 6± 1 6?s, P<0 05) Conclusion Reducing the blood flow velocity in the human left atrium by balloon occlusion of the mitral valve may enhance SEC, whereas restoring blood flow after balloon deflation would cause enhanced echogenic blood to disappear or decrease in both groups of patients Patients with atrial fibrillation demonstrate more severe blood stagnation of the left atrial body and appendage during transient balloon inflation at mitral valve orifice and slower recovery from the stagnation, decreasing to a lesser extent after balloon deflation, when compared to patients with sinus rhythm
基金Supported by The 2008 Neuroradiology Education and Research Fund of the American Society of Neuroradiology partially via the Boston Scientific Fellowship in Cerebrovascular Disease Research Award to Humberto Morales MD,Principal Investigator
文摘AIM: To characterize the effects of iodinated contrast material(ICM) on magnetic resonance imaging(MRI) comparing different sequences and magnetic fields, with emphasis to similarities/differences with well-known signal characteristics of hemorrhage in the brain. METHODS: Aliquots of iopamidol and iodixanol mixed with normal saline were scanned at 1.5T and 3T. Signal intensity(SI) was measured using similar spin-echo(SE)-T1, SE-T2, gradient-echo(GRE) and fluid-attenuationinversion-recovery(FLAIR) sequences at both magnets. Contrast to noise ratio(CNR)(SI contrast-SI saline/SD noise) for each aliquot were calculated and Kruskall-wallis test and graphic analysis was used to compare different pulse sequences and ICMs. RESULTS: Both ICM showed increased SI on SE-T1 and decreased SI on SE-T2, GRE and FLAIR at both 1.5T and 3T, as the concentration was increased. By CNR measurements, SE-T2 had the greatest conspicuity at 3T with undiluted iopamidol(92.6 ± 0.3, P < 0.00) followed by iodixanol(77.5 ± 0.9, P < 0.00) as compared with other sequences(CNR range: 15-40). While SE-T2 had greatest conspicuity at 1.5T with iopamidol(49.3 ± 1, P < 0.01), SE-T1 showed similar or slightly better conspicuity(20.8 ± 4) than SE-T2 with iodixanol(23 ± 1.7). In all cases, hypo-intensity on GRE was less conspicuous than on SE-T2.CONCLUSION: Iodixanol and iopamidol shorten T1 and T2 relaxation times at both 1.5T and 3T. Hypo-intensity due to shortened T2 relaxation time is significantly more conspicuous than signal changes on T1-WI, FLAIR or GRE. Variations in signal conspicuity according to pulse sequence and to type of ICM are exaggerated at 3T. We postulate T2 hypointensity with less GRE conspicuity differentiates ICM from hemorrhage; given the wellknown GRE hypointensity of hemorrhage. Described signal changes may be relevant in the setting of recent intra-arterial or intravenous ICM administration in translational research and/or human stroke therapy.
文摘Purpose: To optimize contrast to noise ratio (CNR) in magnetic resonance imaging (MRI) of prostate cancer using at 3T. Methods: CNR was expressed as a difference in MR signals of two samples. Amulti-echo spin-echo (MESE) pulse sequence was used. The theoretical value of the maximum CNR was obtained using the derivative of CNR with echo time (TE) as a variable. The T<sub>1</sub> relaxation time was ignored as repetition time (TR) was assumed to be very long (TR >> T<sub>1</sub>). The theoretical calculations were confirmed with in vitro and in vivo experiments. For in vitro experiments we used samples with different T<sub>2</sub> values using various concentrations of super paramagnetic iron oxide (SPIO) and for in vivo experiments we used an animal model of prostate cancer. Results: CNR was maximized by selecting the optimum TE for a multi-echo spin-echo (MESE) pulse sequence based on theoretical predictions. MR images of prostate cancer at 3T were obtained and showed maximum CNR at the predicted TE. Conclusions: It was possible to maximize CNR of prostate tumour by selecting the optimal TE based on simple theoretical calculations. The proposed method can be applied to other pulse sequences and tissues. It can be applied to any MRI system at any magnetic field. However the method requires knowledge of T<sub>2</sub> relaxation times.
文摘目的探讨ST段抬高型心肌梗死(STEMI)患者,直接经皮冠状动脉介入治疗(pPCI)术后48 h内心肌血流灌注延迟时间(MFPDT)的临床价值。方法选取并分析71例已行pPCI治疗STEMI患者的临床资料,术后48 h行左心室超声造影检查,分析MFPDT与节段心肌功能(RMF)、左心室射血分数(LVEF)的相关性;依据RMF分为轻度组和严重组,比较两组间MFPDT及LVEF差异及术后平均8.5个月房室大小、LVEF、室壁瘤发生率。正态分布计量资料行t检验,计数资料行χ^(2)检验。采用多因素Logistic回归模型分析室壁瘤形成的影响因素,P<0.05为差异有统计学意义。结果术后48 hMFPDT与RMF呈正相关(r=0.5420,P<0.0001),术后48 h MFPDT与LVEF呈弱相关,与末次随访时LVEF不相关(r分别为-0.2869、-0.1950,P分别为0.0153、0.1034)。心肌受损轻度组31例,室壁瘤4例,严重组40例,室壁瘤18例,两组术后48 h MFPDT及术后室壁瘤发生率比较差异有统计学意义(χ^(2)=19.0280、8.4100,P=0.0003、0.0037),LVEF差异无统计学意义(P>0.05),术后末次随访时两组间房室大小差异无统计学意义(P>0.05)。多因素Logistic回归分析发现,MFPDT是STEMI患者短期预后的主要影响因素(OR=3.0460,P<0.0001,95%CI:1.750~5.301)。结论STEMI患者pPCI术后48 h内MFPDT可初步预测患者心肌损伤严重程度。
文摘目的:评估基于深度学习重建的半傅立叶采集单次激发快速自旋回波(HASTEDL)序列在肝脏检查中的应用价值。方法:使用3.0T MR对36例患者(男28例,女8例)行上腹部MRI扫描,扫描序列包括单次屏气HASTEDL和多次屏气刀锋伪影校正(BLADE)序列。由两位医师分别对肝脏成像质量(锐利度和伪影)进行五分制主观评分。分别在肝门水平肝脏的肝右叶和肝左叶、病灶显示最大层面及其相应层面同一相位方向的右侧背景区放置感兴趣区,测量两组图像上肝脏的信号强度(SI)及其标准差(SD,作为背景噪声),计算图像的信噪比(SNR)和对比噪声比(CNR)。测量病灶最大径(Dmax),观察和记录图像错层率及病灶检出率。对两组图像上肝右叶和肝左叶内肝实质的SNR、CNR,病灶的SNR、CNR、D值,以及图像错层率、图像质量评分结果分别使用Wilcoxon检验或卡方检验进行组间比较。结果:两位医师对两组图像(HASTEDL和BLADE序列)的主观评分和客观测量数据的一致性均为良好(Kappa和ICC值均大于0.75)。两组之间图像锐利度主观评分的差异无统计学意义(4.62±0.55 vs. 4.27±0.65,P=0.289),HASTE-DL组图像伪影的主观评分显著高于BLADE组(4.78±0.48 vs. 4.14±0.98,P<0.001)。HASTEDL组肝左叶和肝右叶内肝组织的SNR、病灶的SNR和CNR均显著高于BLADE组(P<0.001)。两组之间病灶Dmax的差异无统计学意义(P=0.978)。BLADE组的图像错层率明显高于HASTEDL组(P=0.014)。两组中病灶检出率均为100%。结论:基于深度学习重建的单次屏气HASTE序列能有效提高肝脏T2WI图像质量而不会遗漏病灶,并可显著缩短扫描时间,优化肝脏扫描效率,有较好的临床应用前景。
基金We are grateful for the support of the staff of the echocardiography laboratories in the Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. This project was funded by the National Natural Science Foundation of China （Nos. 81401429 and 81271582）. Dr. Li Yuan was a Visiting Fellow at Oxford Echo Core Laboratory, University of Oxford, John Radcliffe Hospital and was financially supported by Oxford University Hospitals Charitable Research Fund.
文摘Contrast echocardiography with left ventricular opacification （LVO） improves the definition of endocardium in two-dimensional echocardiography （2DE）. This study was aimed to determine whether LVO offered added diagnostic value in noncompaetion of left ventricular myocardium （NCVM）. A total of 85 patients （40± 20 years, 54 males） with suspected NCVM were subjected to transthoracic 2DE and LVO, and 40 healthy volunteers were examined with 2DE and assigned as control subjects. The location of NCVM, the thickness ratio of noncompacted to compacted myocardium （NCR）, and the cavity size and ejection fraction of LV were quantified. Results revealed that NCVM was mainly located in the LV medium （53.2%）, apical （46.2%） segments, and lateral wall （39.8%）. The NCR obtained through LVO was greater than that detected through 2DE （4.2 ±1.3 vs. 3.3 ±1.2, P 〈 0.001）, and higher inter-correlations and less intra- and inter-observer variabilities were determined in the former than in the latter. The NCVM detection rates were also increased from 63.5% via 2DE to 83.5% via LVO and 89.4% via 2DE combined with LVO （2DE ＋ LVO） （P = 0.0004）. The LV cavity size was greater and the LV ejection fraction （LVEF） was lower in the NCVM patients than in the control group （P 〈 0.01）. In the NCVM group, the LV cavity size was higher and the LVEF was lower in LVO than in 2DE （P 〈 0.01）. In conclusion, contrast echocardiography contributes significant sensitivity and reproducibility to routine transthoraeic echoeardiography in NCVM diagnosis. Therefore, this technique should be clinically performed to diagnose suspected NCVM.
