A study on the relationship between biomarkers and left ventricular myocardial native T 1 value in patients with lone atrial fibrillation / 中华放射学杂志

Objective:To investigate the relationship between serum procollagen Ⅲ amino terminal peptide (PIIINP), collagen I carboxyl terminal cross-linking peptide (CTXI), high-sensitivity C-reactive protein (hs-CRP) and cardiac magnetic resonance (CMR) T 1 mapping value in patients with lone atrial fibrillation (AF). Methods:Fifty-five patients with lone AF in Beijing Anzhen Hospital from July 2017 to June 2018 were prospectively enrolled. Another 20 healthy volunteers were examined at the same time to provide normal reference range. All patients completed PIIINP, CTXI, hs-CRP and CMR examination within one week. CMR examination including cine, pre-contrast T 1 mapping, and late gadolinium enhancement sequences. We used t test, Mann-Whitney U test or chi square test to compare the difference of the above indexes between AF patients and the control group. Spearman correlation analysis was used to determine the associations between left ventricular native T 1 value and blood biomarker in AF patients. Results:All the patients were paroxysmal AF with an average age of (48±10) years, of which 46 (83.6%) were male. The PIIINP, CTXI, hs-CRP, left ventricular native T 1 value of AF patients were 5.83 (3.52, 12.40) ng/ml, 4.63 (3.31, 6.82) μg/ml, 3.41 (1.72, 6.61) mg/L and (1 261±23) ms, respectively, which all significant higher than those in healthy subjects (all P<0.05). The native T 1 value of left ventricular myocardium was positively correlated with PIIINP ( r=0.492, P<0.05) and hs-CRP ( r=0.516, P<0.05), but not with CTXI ( r=0.021, P>0.05). Conclusions:The PIIINP, CTXI and hs-CRP increased in patients with lone AF, PIIINP and hs-CRP were correlated with elevated native T 1 value of left ventricular myocardium.

Evaluation of pulmonary artery blood flow and right heart function using phase-contrast magnetic resonance imaging in elderly patients with chronic obstructive pulmonary disease / 中华老年医学杂志

Objective To investigate the value of phase-contrast magnetic resonance imaging (PC-MRI)in evaluating pulmonary artery blood flow and right ventricular(RV)function in elderly patients with chronic obstructive pulmonary disease (COPD).Methods Twenty-four elderly patients with COPD admitted to Beijing Anzhen Hospital between February 2016 and June 2017 were enrolled in this retrospective study.Based on pulmonary artery pressure evaluated by right heart catheterization,COPD patients were divided into a pulmonary hypertension group (PH group,n =12)and a non-PH group(n=12).Pulmonary artery blood flow velocity and volume,pulmonary arterial compliance and right heart function parameters including ejection fraction,end diastolic volume,endsystolic volume and cardiac output,and 6-min walking distance evaluated by PC-MRI were compared between the two groups.Results There were significant differences in peak flow velocity[(88.1 ±16.0)cm/s vs.(59.8± 13.8) cm/s,P =0.005],flow volume [(80.7± 22.0) ml/s vs.(53.2± 26.7)ml/s,P=0.012],main pulmonary artery compliance[(42.3± 14.6)vs.(22.7± 10.8),P =0.001],right ventricular ejection fraction [(48.4 ± 13.4) ％ vs.(37.6 ± 11.1) ％,P =0.000],end-diastolic volume[(64.6±22.5)ml vs.(72.5±22.8)ml,P =0.030]and end-systolic volume[(50.6±33.1)ml vs.(41.7±33.1)ml,P =0.040]between the non-PH and PH groups,while there was no significant difference in cardiac output between the non-PH and PH groups[(34.2±10.8)ml vs.(34.4±8.3)ml,P =0.080].Pearson's correlation analysis showed that 6-minute walking distance had good correlations with right ventricular ejection fraction(r =0.49),forced expiratory volume in 1 s(FEV1)(r=0.60)and main pulmonary artery diameter(r=0.61).Conclusions PC-MRI is a noninvasive imaging method for quantitative analysis of pulmonary artery dynamics and right heart function for the elderly with COPD,and it can provide information for evaluating therapeutic effects and prognosis.

Value of cardiac MR in evaluating myocardial infarction with chronic mitral insufficiency / 中华放射学杂志

Objective To evaluate the value of cardiac MR imaging in chronic ischemie mitral regurgitation (IMR) in patients with myocardial infarction. Methods All patients clinically diagnosed with coronary heart disease and myocardial infarction in our hospital from January 2016 to September 2018 were retrospectively selected, myocardial infarction time more than 3 months and confirmed to have necrotic myocardium by cardiac magnetic resonance examination. All patients underwent echocardiography at the same time. Based on the results of echocardiography, patients were divided into the myocardial infarction group without IMR (40 cases), the mild IMR group (39 cases) and the moderate to severe IMR group (51 cases). Cardiac MR and delayed enhancement (LGE) scan images were analyzed. Cardiac function indexes were measured and left ventricular LGE positive segments were recorded. The indexes of myocardial global longitudinal strain (GLS), global peripheral strain (GCS) and global radial strain (GRS) of left ventricle of IMR patients were measured by feature tracking(FT). Cardiovascular history, coronary artery stenosis and location of myocardial infarction were compared by chi?square test between the without IMR, mild IMR and moderate to severe IMR groups.Univariate analysis of variance was used to compare the measurement data of left ventricular myocardial infarction volume, left heart function and left ventricular myocardial globle strain, and LSD test was used for pair?wise comparison. Results There was no difference in age, sex and cardiovascular history among the three groups. Comparison of myocardial infarction patients in the three groups: (1) There was no statistically significant difference in the myocardial infarction volume between the three groups (P=0.052), while the myocardial infarction volume tended to increase as the grade of mitral regurgitation increased. The number of patients with myocardial infarction in the inferior wall and the inferolateral wall in the moderate to severe IMR group were significantly higher than those of the other two groups (P<0.05), and there was no significant difference in the volume of myocardial infarction between the without IMR group and mild IMR group, and no difference in the number of patients with inferior wall and inferolateral wall. (2) Cardiac function measured by CMR: ejection fraction (EF) was significantly reduced in the moderate to severe IMR group compared with the without IMR group and the mild IMR group (P<0.05), the end diastolic volume (EDV) increased significantly and the end systolic volume (ESV) increased significantly (P<0.05). Mass of myocardium increased significantly (P<0.05); Stroke volume (SV) and cardiac output (CO) there was no significant difference among the three groups. (3) Comparison of the moderate to severe IMR group to the without IMR group and the mild IMR group respectively: left ventricular GLS and GRS decreased (P<0.05), the difference of the GCS was no statistically significant. There was no statistical difference in the three strain values between the without IMR group and the mild IMR group. Conclusion The globe myocardial strain of the left ventricle in myocardial infarction patients with chronic moderate to severe IMR was significantly impaired, the myocardial infarction in the inferior wall and the inferolateral wall in the level of the papillary muscle may be correlated with chronic moderate to severe IMR, and the myocardial infarction volume of the left ventricle may also be related.

Value of cardiac MR in evaluating myocardial infarction with chronic mitral insufficiency / 中华放射学杂志

Objective@#To evaluate the value of cardiac MR imaging in chronic ischemie mitral regurgitation (IMR) in patients with myocardial infarction.@*Methods@#All patients clinically diagnosed with coronary heart disease and myocardial infarction in our hospital from January 2016 to September 2018 were retrospectively selected, myocardial infarction time more than 3 months and confirmed to have necrotic myocardium by cardiac magnetic resonance examination. All patients underwent echocardiography at the same time. Based on the results of echocardiography, patients were divided into the myocardial infarction group without IMR (40 cases), the mild IMR group (39 cases) and the moderate to severe IMR group (51 cases). Cardiac MR and delayed enhancement (LGE) scan images were analyzed. Cardiac function indexes were measured and left ventricular LGE positive segments were recorded. The indexes of myocardial global longitudinal strain (GLS), global peripheral strain (GCS) and global radial strain (GRS) of left ventricle of IMR patients were measured by feature tracking(FT). Cardiovascular history, coronary artery stenosis and location of myocardial infarction were compared by chi-square test between the without IMR, mild IMR and moderate to severe IMR groups.Univariate analysis of variance was used to compare the measurement data of left ventricular myocardial infarction volume, left heart function and left ventricular myocardial globle strain, and LSD test was used for pair-wise comparison.@*Results@#There was no difference in age, sex and cardiovascular history among the three groups. Comparison of myocardial infarction patients in the three groups: (1) There was no statistically significant difference in the myocardial infarction volume between the three groups (P=0.052), while the myocardial infarction volume tended to increase as the grade of mitral regurgitation increased. The number of patients with myocardial infarction in the inferior wall and the inferolateral wall in the moderate to severe IMR group were significantly higher than those of the other two groups (P<0.05), and there was no significant difference in the volume of myocardial infarction between the without IMR group and mild IMR group, and no difference in the number of patients with inferior wall and inferolateral wall. (2) Cardiac function measured by CMR: ejection fraction (EF) was significantly reduced in the moderate to severe IMR group compared with the without IMR group and the mild IMR group (P<0.05), the end diastolic volume (EDV) increased significantly and the end systolic volume (ESV) increased significantly (P<0.05). Mass of myocardium increased significantly (P<0.05); Stroke volume (SV) and cardiac output (CO) there was no significant difference among the three groups. (3) Comparison of the moderate to severe IMR group to the without IMR group and the mild IMR group respectively: left ventricular GLS and GRS decreased (P<0.05), the difference of the GCS was no statistically significant. There was no statistical difference in the three strain values between the without IMR group and the mild IMR group.@*Conclusion@#The globe myocardial strain of the left ventricle in myocardial infarction patients with chronic moderate to severe IMR was significantly impaired, the myocardial infarction in the inferior wall and the inferolateral wall in the level of the papillary muscle may be correlated with chronic moderate to severe IMR, and the myocardial infarction volume of the left ventricle may also be related.

Preliminary application of optimized temporal parallel acquisition technique real-time cine sequence in cardiac MRI in arrhythmia patients / 中国医学影像技术

Objective To observe the value of optimized temporal parallel acquisition technique (TPAT) sequence in evaluating cardiac structure and function in arrhythmia patients.Methods Totally 33 arrhythmia patients (arrhythmia group) and 48 normal rhythm subjects (normal group) underwent cardiac MRI with conventional cine (balanced steadystate free-precession [bSSFP]) sequence and optimized TPAT sequence.Myocardial thickness,cardiac function,myocardial strain parameters of left ventricle and image quality of 2 sequences were compared in the two groups,respectively.Results In arrhythmia group,there was statistical difference of myocardial thickness in 12 myocardial segments between the 2 sequences (all P ＜ 0.05),as well as peak and average values of myocardial radial and circumferential strain (all P＜0.05).In normal group,there was no statistical difference of myocardial thickness and stain parameters between the 2 sequences (all P＞0.05).Additionally,no statistical difference of cardiac function was found between the 2 sequences in two groups (all P＞0.05).In arrhythmia group,the image quality of optimized TPAT sequence was better than that of bSSFP sequence (P＜0.05).Conclusion For arrhythmia patients,optimized TPAT cine sequence could improve image quality of cardiac MRI.

A preliminary study on the relationship between idiopathic arrhythmia and cardiac magnetic resonance imaging defined cardiac features in patients with straight back syndrome / 中华心血管病杂志

Objective@#To retrospectively analyze the potential correlation between cardiac magnetic resonance (CMR) imaging and clinical features and idiopathic arrhythmia in patients with straight back syndrome (SBS).@*Methods@#Patients receiving CMR imaging examination from April 2015 to March 2016 at our department (n=1 432) were screened, 76 patients met the diagnosis criteria of flat chest (anteroposterior diameter/transthoracic diameter (APD/TTD) ratio<0.37 at the T8 vertebra). After excluding 33 patients with structural heart disease, 43 SBS patients were divided into two groups: SBS without obvious morphological change in the heart (group A, n=19) and SBS with morphological change of the heart (group B, n=24). CMR images were analyzed, focusing the heart morphological changes induced by SBS. The clinical data were collected to comprehensively analyze the medical history, electrocardiogram and electrophysiological examination in order to observe the relationship between SBS induced heart morphological change and the arrhythmia type and origin.@*Results@#There were 21 male patients in this cohort, mean age was (28.5±11.5) years (13-58 years). APD/TTD ratio was similar between the two groups (0.30±0.03 vs. 0.29±0.04, P>0.05). LVEF tended to be lower in group B than in group A ((47.48±12.77)%vs. (59.31±9.04)%, P>0.05) . In group B, there were 15 patients with left ventricular enlargement, 2 with left ventricular wall thickening, 5 with uncoordinated ventricular wall motion, 5 with tricuspid regurgitation, 3 with mitral regurgitation, 2 with myocardial fibrosis, 5 with increased trabecular and 16 with decreased left ventricular function. Direct compression sign of right ventricle (disappeared precordial fat tissue space, secondary right atria enlargement and tricuspid regurgitation) and left atria (with or without secondary left ventricular enlargement and mitral regurgitation) were evidenced in patients of group B. CMR revealed that the arrhythmia origin corresponded the compression site of the heart in 8 cases (42.1%) in group A and 13 cases (54.2%) in group B, not corresponded to the compression site in 6 patients (31.6%) in group A and in 7 patients (29.2%) in group B, not attributable in 5 patients (26.3%) in group A and 4 patients (16.7%) in group B. The percent of arrhythmia origin corresponded the compression site of the heart tended to be higher in group B as compared to group A (P>0.05).@*Conclusion@#SBS can induce changes of cardiac morphology and cardiac function. SBS induced cardiac compression is linked with the development of arrhythmias and might be one of the reasons of arrhythmias in these patients.

A preliminary study of left ventricular function assessement in patients with atrial fibrillation by MR feature tracking technique / 中华放射学杂志

Objective To explore the clinical application value of left atrial function with feature tracking cardiac magnetic resonance imaging (FT-CMR) by evaluating preliminarily left atrial strain and strain rate in patients with atrial fibrillation. Methods Thirty patients with paroxysmal atrial fibrillation, thirty patients with persistent atrial fibrillation and twenty-two healthy subjects were enrolled. All the subjects underwent cardiac magnetic resonance imaging with the real steady-state free precession(SSFP) sequence. FT-CMR parameters included left atrial strain and strain rate parameters, left atrial volume and function parameters were detected by using offline cardiovascular analysis software, respectively. Left atrial strain and strain rate parameters included left atrial total strain(Εs), passive strain(Εe), active strain(Εa), peak positive strain rate(SRs), peak early negative strain rate(SRe)and peak late negative strain rate(SRa). Volume and function parameters included maximum of left atrial volume(LAVmax), minimum of left atrial volume(LAVmin), total left atrial emptying fraction(LATEF), passive left atrial emptying fraction(LAPEF)and active left atrial emptying fraction(LAAEF). The differences in the general data among the paroxysmal atrial fibrillation group, the persistent atrial fibrillation group and the control group were compared by usingχ2 test or ANOVA analysis. The differences in all parameters between the atrial fibrillation group and the control group, the paroxysmal atrial fibrillation group and the persistent atrial fibrillation group were compared by using independent t test. Left atrial strain and strain rate parameters on an intra-observer and inter-observer were determined by intraclass correlation coefficient(ICC)analyses. Results Compared to control group, LAVmax and LAVmin in atrial fibrillation group were significantly increased(t=9.737,7.889,P<0.001);The LATEF and LAPEF had no significant difference, the LAAEF in two groups had statistically significant difference(t=-4.762,P<0.001).The absolute value of Es, Ee, Ea, SRs, SRe, SRa in atrial fibrillation group were significantly reduced than in control group(t=-7.732,-6.610,-6.493,-7.546, 6.864, 5.917,P<0.001). Compared with paroxysmal atrial fibrillation group, LAVmax and LAVmin in persistent atrial fibrillation group were increased obviously, LATEF and LAPEF were significantly decreased, and the differences were statistically significant(t=-4.575,-5.524, 4.002, 4.028,P<0.001).The LAAEF in two groups had no statistically significant difference. Compared with strain and strain rate in two groups, absolute value of Es, Ee, Ea, SRs, SRe, SRa in persistent atrial fibrillation group significantly decreased than in paroxysmal atrial fibrillation(t=4.310, 3.128, 4.465, 5.496,-3.290,-3.863,P<0.001). The intra-group and inter-group had well correlation coefficients between the observers in the left atrial strain and strain rate parameters of the subjects(ICC=0.85—0.94,0.81—0.90). Conclusions FT-CMR technique can be used to assess the left atrial strain and strain rate in patients with atrial fibrillation;Left atrial reservoir, conduit and booster-pump functions in patients with atrial fibrillation were impaired. Patients with persistent atrial fibrillation had worse left atrial function throughout the entire cardiac cycle compared with those with paroxysmal atrial fibrillation.

Quantitative analysis of left ventricle myocardial fibrosis in patients with atrial fibrillation by cardiac MRI / 中国医学影像技术

Objective To evaluate the diffuse myocardial fibrosis of the left ventricle (LV) in patients with atrial fibrillation (AF) by cardiac MR (CMR) T1 mapping methods.Methods Totally 60 subjects (30 paroxysmal AF patients and 30 persistent AF patients) and 59 normal control underwent MR cardiac cine,late gadolinium enhancement,and LV T1 mapping.For T1 mapping,modified Look-Locker inversion recovery sequence was used.Compared with control,pre-contrast ventricular T1 times were quantified and extracellular volume (ECV) was calculated.Results All subjects completed the CMR exam,no myocardial delay enhanced lesion was found.Pre-contrast ventricular T1 time in healthy controls was lower than that in patients with persistent and paroxysmal AF,and the pre-comrast ventricular T1 time in persistent AF patients was higher than that of paroxysmal AF patients (all P＜0.05).The mean LV myocardial ECV had no statistical difference between healthy controls and paroxysmal AF patients (P＞ 0.05),while lower than persistent AF patients (P ＜ 0.05).The mean LV myocardial ECV in patients with persistent AF was larger than that in patients with paroxysmal AF (P＜0.05).LV functional indexes were positive correlated with pre-contrast ventricular T1 time and ECV in patients with AF (all P＜0.05).Conclusion There is LV myocardial fibrosis in patients with AF,and the degree in patients with persistent AF is more severe than that in patients with paroxysmal AF.

Research progresses of cardiac MRI in evaluation on pathological changes of myocardial infarction / 中国医学影像技术

The myocardial infarction is an important clinical feature of ischemic heart disease,and its various stages of histopathological changes are closely related to the prognosis of patients.In recent years,with the continuous development and improvement of MRI software and hardware techniques,the cardiac MR (CMR) can assess the pathological changes of the myocardial infarction by its multi-parameter and multi-sequence imaging techniques qualitatively and quantitatively.And the CMR can provide the clinical reference information for the patients in short-term diagnosis and long-term prognostic risk assessment accurately and comprehensively.The progresses of CMR in assessing the pathology of myocardial infarction were reviewed in this article.

Evaluation of diffuse myocardial fibrosis of cardiomyopathy by using T1 mapping：initial study / 中华放射学杂志

Objective To investigate the value of contrast enhancement T1 mapping in detection of diffuse myocardial fibrosis in cardiomyopathy, and the relationship between myocardial fibrosis and cardiac function. Methods From September 2013 to September 2014, 76 cases of cardiomyopathy patients (including myocarditis) and 33 cases of healthy controls were enrolled in our study. All the subjects underwent cardiac MR (CMR) examination. Scan sequences included cine MR, pre-contrast and post-contrast T1 mapping and late gadolinium enhancement (LGE) imaging. The pre-/post-contrast left ventricle average T1 value and cardiac function of patients and controls were measured and compared by using independent-samples t test. According to the LGE imaging, all the subjects were subsequently divided into LGE positive group, LGE negative group and control group. The myocardial average T1 value and cardiac function among the three sub-groups were compared by using one-way ANOVA, and the relationship among them were analyzed by using Pearson correlation. Results Among the 76 cases of non-ischemia cardiomyopathy patients, 51 cases (67.1%) had LGE. Compared with controls, cardiomyopathy patients presented with higher pre-contrast T1 value [(1 306.4 ± 84.6)ms vs. (1 266.6 ± 57.3)ms, t=2.10, P0.05). There were correlation between pre-/post-contrast left ventricle T1 value and ejection fraction (EF) in cardiomyopathy patients (r=-0.252,-0.217, P0.05). Conclusions The average pre-/post-contrast T1 value in left ventricle myocardium are helpful for detection of diffuse fibrosis in cardiomyopathy patients. The LGE positive is a sign that can greatly change the T1 value of the myocardial tissue, meanwhile, myocardial fibrosis is negative correlated with ejection fraction in cardiomyopathy patients.

Myocardial Fibrosis in Hypertrophic Cardiomyopathy：Assessed by Delayed-enhanced CT / 中国医学影像学杂志

PurposeTo determine the feasibility and accuracy of dual source CT (DSCT) in assessing myocardial delayed-enhancement and left ventricular wall thickness of hypertrophic cardiomyopathy (HCM) in comparison with cardiac magnetic resonance (CMR).Materials and MethodsEighty patients with HCM confirmed by clinical diagnosis were enrolled in the study. DSCT images and CMR images were acquired at the arterial and lag phases. According to 17-segment model provided by American Heart Association, the left ventricular wall thickness and location of delayed-enhancement were verified, and the correlation of these two methods were analyzed in terms of the diagnosis of myocardial delayed enhancement (MDE).Results1360 myocardial segments for 80 patients were assessed. The left ventricular wall thickness determined by DSCT was significantly correlated with MR results (r=0.88,P<0.01). DSCT and MDE showed substantial agreement on per-patient (n=74,Kappa=0.751,P<0.05) and per-segment (n=1238, Kappa=0.746,P<0.01) levels. For dense myocardial delayed enhancement, CT findings were significantly correlated with those of CMR (r=0.89, P<0.01), but CT scan slightly underestimated the lesion scope of fibrosis. Bland-Altman analysis showed that CT and MRI were different in measuring the lesion volume of myocardial delayed enhancement (mean standard deviation was 2.71%).ConclusionThe cardiac CT examination provides comprehensive information in coronary artery and myocardial assessment, and MDE-DSCT is also effective in the diagnosis of myocardial fibrosis in HCM since it can be used in assessing myocardial fibrosis.

A feasibility study in 3.0 T MR imaging using an improved intravascular coil / 中华放射学杂志

Objective The study was to investigate the feasibility of using an intravascular Loopless Monopole Antenna (ILMA) for 3.0 T MR imaging of water bath and deep-seated arterial walls of experimental animal.Methods A novel intravascular loopless monopole antenna (ILMA) was developed,including a non-shield loach guide-wire and a matching circuit.The non-shield loach guide-wire is used as a receive antenna,with the diameter of 0.019 in( 1 in =2.54 cm) and length of 23.11 in.During the MR scanning,the ILMA was used as a receive-only probe,while body coil was used to transmit the RF pulses.Utilizing the coil in water bath and in-vivo animal experiment,we measured signal-to-noise ratio (SNR) and contrast-to-noise ratio(CNR) of artery wall using the same scanning parameter compared with phased-array coil.Results In the study,the developed novel ILMA conduced to improved SNR of imaging and much higher space resolution( 313 μm).First,the feasibility of acquiring the wall images was demonstrated on phantoms.The SNRs map generated by the matlab software showed that in comparison with the phased-array coil,ILMA generated higher SNR of the phantom wall when using the same sequences,parameters,and slices (86.8 ±0.8 vs.9.9 ±0.1,P ＜0.01 ).When imaging the aorta wall with the ILMA and phased-array coil,the SNRs of the arterial wall with the ILMA is 60.4 ±20.9,61.3 ±22.5,59.8 ±20.4,32.3 ±22.6 (T1WI),51.2 ±21.6,49.8 ± 15.5,50.4 ± 17.2,22.4 ± 18.3 (T2WI),the CNRs of the aorta wall with theILMA is 19.8±8.1,18.9±9.2,19.6±11.8,20.7 ± 13.3(T1WI),17.7±6.4,18.6±6.9,17.2 ± 6.4,17.2 ± 6.4 ( T2 WI),compared with phased-array coil,t values SNR:6.36,3.84,3.51,6.92(T1 WI),3.47,4.89,6.35,4.21 (T2WI),CNR:3.56,3.97,-0.71,4.74 (T1WI),3.99,3.01,4.27,5.03(T2 WI,P ＜ 0.05 ),respectively.Conclusion The study demonstrates the capability of using an MR ILMA to generate 3.0 T MR in-vivo experiments,the developed novel ILMA conduces to increased SNR compared with the conventional phased-array coil.

Detection of thrombosis and plaque rupture in atherosclerotic rabbit model by using 3.0 T MR imaging / 中华放射学杂志

ObjectiveTo explore the imaging of the thrombosis after pharmacological triggering of plaque rupture in atherosclerotic rabbit model by using 3.0 T high-resolution magnetic resonance imaging.MethodsTwenty male New Zealand white rabbits were divided into an experimental group (n = 16) and a control group (n = 4).The aortic wall injuries were induced by an intravascular balloon in experimental group rabbits after high cholesterol diet.The pharmacological triggering with Russell's viper venom and histamine was performed after 3 months of establishment of model.All of the animals underwent pre-trigger and post-trigger MR examinations including 3D time of fight (3D TOF),T1 WI,T2WI and post contrast T1 WI.Euthanasia was performed in all rabbits and gross anatomy and histological specimen of aorta were obtained.Comparing the location and length of the thrombus between MRI images and histopathology was used Pearson test.Comparing the calculated indexes of abdominal aorta between rabbits with and without thrombosis was used AVONA test and LSD-t test.Results After triggering,8 in 14 survived rabbits developed thrombosis in experimental group,meanwhile,no thrombus was found in control group.The accuracy of multi-sequences MRI for detecting of thrombus was 87.1％ (27/31).MRI data correlated with the histopathology regarding thrombus length ( r = 0.85,P ＜ 0.01 ) and thrombus location ( r = 0.94,P＜0.01 ).Compared with rabbits without thrombosis,the rabbits with thrombosis had narrower lumen of abdominal aorta in the pre-triggered MR images [ ( 5.71 ± 2.38 )mm2 vs.( 8.93 ± 5.36) mm2,P ＜ 0.01 ].ConclusionMRI is useful tool to determine the thrombosis and plaque rupture in atherosclerotic rabbit model.

Low-dose adaptive sequence scan of dual-source CT coronary angiography in patients with high heart rate: an initial study / 中华放射学杂志

Objective To investigate the application of low-dose adaptive sequence scan of dual-source CT coronary angiography in patients with high heart rate and evaluate the image quality.Methods Seventy-two patients who underwent coronary CT angiography with heart rate> 70 bpm were divided into 2 groups.Group A was adaptive sequence scan, and Group B was retrospective ECG-gating helical scan.Examinations were performed on a dual-source CT scanner (Somatom Definition) .All images were transferred to a workstation for further processing and analysis.The image quality was evaluated using same criteria.The image quality of coronary artery segments was compared in two groups using rank sum test, and the radiation dose was compared using t test Results A total of 501 coronary artery segments were evaluated in group A and 400 segments in group B.The mean ranks in image quality of coronary artery segments in group A was 475.42, whereas 420.41 in group B.There was a statistical difference in image quality between the two groups (Z= - 3.509,P=0.000).The effective dose was on average (6.2±0.9) mSv in group A, whereas on average (14.7±1.9) mSv in group B, there was a statistical difference between the two groups(t= - 27.011, P=0.000).Conclusions Adaptive sequence scan in dual-source CT coronary angiography is feasible in patients with high heart rates.This scan mode can substantially reduce radiation dose and maintain the diagnostic image quality.

A study of neurological complications after coronary artery bypass grafting / 中华内科杂志

Objective To prospectively investigate the neurological complications(NC)after offpump coronary artery bypass grafting(OPCABG),including the kinds of NC and their mobility,risk factors.prevetion and treatment.Methods A total of 55 consecutive patients with undergoing OPCABG were evaluated from March to June 2006 at the Department of Cardiosurgery in Beijing Anzhen Hospital.Risk factors of NC were collected before operation.Nervous system physical examination,The NIH Stroke Scale(NIHSS)score evaluation,cognitive tests,imaging examination(MRI,MRA and f-MRI),anxious and depression scale were performed before and after OPCABG.NC and their kinds were identified after surgery.According to the presence or absence of NC after the operation,the patients were divided into two groups,and univariate analysis was used between the two groups.P＜0.05 was considered of statistically significant difference.Results (1)2 cases of ischemic stroke developed after surgery(2/55),but there no case of mortality.The risk factors were not statistically different between the two groups(P＞0.05):(2)For all the patients,cognitive evaluation was normal and unchanged before and after surgery(P＞0.05),including Mini-Mental State Examination(MMSE),Clinical dementia rating(CDR)and Global Deterioration Scale (GDS);(3)Except the 2 cases of stroke,the others were normal and had no change on MRI,MRA,and f-MRI(P＞0.05)before and after surgery;(4)7 patients with slight anxiety and one with sight depression before operation recovered completely after surerty without treatment.Both the Self-rating Anxiety Scale (SAS)and Self-rating Depression Scale(SDS)were normal and unchanged before and after surgery (P＞0.05).Conclusions 2 cases of ischemic stroke were found among 55 patients undergoing OPCABG (2/55)and there was no mortality.There was no obvious change of cognitive function,imaging finding,anxiety and depression before and after the operation(P＞0.05).OPCABG is relatively safe for nervous system,but more exploratory work andclinical data are needed.

Relationship between the cerebral blood flow filling condition and prognosis of patients with acute severe cerebral infarction / 临床神经病学杂志

Objective To investigate the relationship between the cerebral blood flow filling condition and prognosis of patients with acute severe cerebral infarction.Methods The clinical data and MR features of 10 cases of acute severe cerebral infarction were retrospectively analyzed.Results The regional cerebral blood flow(rCBF) and regional cerebral blood volume(rCBV) of 9 cases(90%) in the infarcted side decreased significantly.The reduced percents of the infarcted side reached 64.1% and 49.7% respectively.There were significant differences between two opposite sides(P=0.001,P=0.01).The MRA results showed great vessels(arteria carotis interna or arteria cerebri media) in the infarcted side were all obliterated in the all patients,and simultaneous great vessels in opposite side were narrow or occlusion in 7 cases(70%).2 cases died;and 8 cases were serious disability.Conclusions The cerebral blood flow filling of the acute severe cerebral infarction patients decrease significantly.The prognosis of the patients is quite bad.