超声数据3D打印制作二尖瓣模型的可行性

目的探讨以3D-经食管超声心动图(TEE)为数据源,采用3D打印技术制作二尖瓣(MV)模型的可行性。方法获取30例患者的MV 3D-TEE图像,其中MV正常、MV狭窄、MV脱垂各10例,使用铸模硅胶灌注成型法制作MV 3D模型。测量并对比3D模型及3D-TEE图像上二尖瓣前后径、前外后内侧径、瓣环周长、瓣环面积及瓣膜开放幅度,计算二者间MV上述测值的绝对差值。结果 30例3D-TEE图像均成功后处理并打印制作出MV 3D模型。3D模型与3D-TEE图像间各参数测值差异均无统计学意义(P均>0.05),且各参数测值的绝对差值均较小。结论采用3D-TEE和3D打印技术制作MV模型可行,且具有高保真度。     

Left ventricular endocardial pacing: a transarterial approach

INTRODUCTION: We tested the feasibility of a new technique of direct left ventricular endocardial lead placement across the aortic valve in a chronic (six month) pig model. The potential for aortic valve damage, systemic embolization, and pacing lead maturation and function within the left ventricle are unknown. METHODS: Ten minipigs were successfully implanted with a transaortic left ventricular lead (Medtronic CapSureFix, Minneapolis, MN, USA) placed in the left ventricular apex via the carotid artery. Each pig received either a polyurethane (n = 5) or silicone (n = 5) lead. Post implant each pig received clopidogrel and aspirin for seven days. After six months all surviving pigs underwent thorough necropsy. RESULTS: Each pig had adequate sensing (12.1 +/- 4 mV) and pacing thresholds (0.79 +/- 0.2 @ 0.5 V) at implant. Postoperatively two pigs died of a respiratory illness. One pig died postoperatively due to sepsis. At the six-month follow-up, all surviving pigs (n = 7) were in a healthy state. Of the pigs without dislodgement (n = 5) there was adequate sensing, but a rise in pacing thresholds. Echocardiography revealed a normal ejection fraction and only trace to mild aortic insufficiency in all pigs. Of the seven surviving pigs there were no thromboembolic events noted. One silicone lead was noted to have thrombosis along the lead screw and shaft. CONCLUSION: Direct transaortic placement of a left ventricular lead is feasible. After six months, there was no significant aortic regurgitation and no evidence of thromboembolism despite no anticoagulation. Lead function was acceptable and only one silicone lead (and no polyurethane lead) was noted to have significant thrombosis.     

Automatic real-time endocardial edge detection in two-dimensional echocardiography

Previous approaches to automatic border recognition in two-dimensional echocardiography have utilized off-line computer image analysis. In this paper, we describe a hardware technique for real-time endocardial edge detection during the echocardiographic examination. This technique is based on a new method of line-by-line compensation for ultrasound attenuation. The detected edges and composite edge images can be displayed alone or superimposed upon the usual echocardiographic display. To test the accuracy of our real-time technique, we obtained echocardiograms of excised hearts and compared real-time edges with edges manually traced by an experienced observer. Left ventricular cavity areas and endocardial perimeters derived from real-time edges correlated well with those derived from observer-defined edges.     

Left ventricular endocardial calcification in a patient with myeloproliferative disease

The case of a 57-year-old male with a history significant for myeloproliferative disease, chronic renal failure, hypertension, and prostate cancer is described. His complete blood count was remarkable for neutrophilia and, notably, eosinophilia. Subsequent to two syncopal episodes, a transthoracic echocardiogram was performed as part of the workup, which showed an unusual calcified mass in the left ventricular apical region but separate from the apical myocardium, with normal left ventricular systolic function. A transesophageal echocardiogram and computed tomography of the chest confirmed the presence of extensive calcification in the left ventricle of unusual location and shape. This patient probably had Loeffler endocarditis related to myeloproliferative disorder, complicated by calcification of the endocardial sclerotic lesions.     

Improved quantification of left ventricular volumes and mass based on endocardial and epicardial surface detection from cardiac MR images using level set models.

PURPOSE: The reproducibility of left ventricular (LV) volume and mass measurements based on subjective slice-by-slice tracing of LV borders is affected by image quality, and volume estimates are biased by geometric modeling. The authors developed a technique for volumetric surface detection (VoSD) and quantification of LV volumes and mass without tracing and geometric approximations. The authors hypothesized that this technique is accurate and more reproducible than the conventional methodology. METHODS: Images were obtained in 24 patients in 6 to 10 slices from LV base to apex (GE 1.5 T, FIESTA). Volumetric data were reconstructed, and endocardial and epicardial surfaces were detected using the level set approach. LV volumes were obtained from voxel counts and used to compute ejection fraction (EF) and mass. Conventional measurements (MASS Analysis) were used as a reference to test the accuracy of VoSD technique (linear regression, Bland-Altman). For both techniques, measurements were repeated to compute inter- and intra-observer variability. RESULTS: VoSD values resulted in high correlation with the reference values (EDV: r = 0.98; ESV: r = 0.99; EF: r = 0.91; mass: r = 0.98), with no significant biases (8 ml, 5 ml, 0.2% and -9 g) and narrow limits of agreement (SD: 13 ml, 10 ml, 6% and 9 g). Inter-observer variability of the VoSD technique was lower (range 3 to 5%) than that of the reference technique (5 to 11%; p < 0.05). Intra-observer variability was also lower (1 to 3% vs. 7 to 10%; p < 0.05). CONCLUSION: VoSD technique allows accurate measurements of LV volumes, EF, and mass, which are more reproducible than the conventional methodology.     

Single-beat real-time three-dimensional echocardiographic automated contour detection for quantification of left ventricular volumes and systolic function

To assess the feasibility and accuracy in measuring left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) with Siemens single-beat real-time 3D transthoracic echocardiography. The LV volumes and EF were measured in 3D datasets acquired by six imaging modes (time-1-harmonic (T1H), time-1-fundamental, time-2-harmonic, time-2-fundamental, space-1-harmonic (S1H), and space-1-fundamental) in 41 patients using the automated contouring algorithm and compared with manually corrected 3DE QLAB measurements. The main determinates of the temporal and spatial resolutions of 3D datasets acquired were the fundamental and harmonic modes. Consequently, the S1H mode had the lowest volume rate and highest spatial resolution. Compared with the 3DE QLAB analysis, the S1H mode resulted in the best LV volumes and EF estimates in all patients (0 ± 10 % for EF, ?7 ± 44 ml for EDV, ?7 ± 39 ml for ESV) and in the 10 patients with correct LV contour tracking according to a visual assessment from the multiplanar reconstruction views in all six modes (0 ± 9 % for EF, ?3 ± 23 ml for EDV, ?2 ± 14 ml for ESV). The T1H mode was the best alternative. Overall 28 patients (68 %) could be analysed automatically and satisfyingly with the S1H and T1H modes: 0 ± 8 % (EF), 0 ± 27 ml (EDV) and ?1 ± 16 ml (ESV). The accuracy of the Siemens automated RT-3D algorithm in measuring LV volumes and EF is significantly influenced by the different imaging modes. The S1H mode may be the preferred 3D acquisition mode, supplemented by the T1H mode in enlarged LVs that do not fit in the S1H acquisition sector.     

Left ventricular function in end-stage renal disease: echocardiographic classification

We used echocardiography (ECHO) to detect pericardial effusions and assess left ventricular (LV) function in 39 patients with end-stage renal disease (ESRD). Pericardial effusions were present in 24 patients (62%). Thirty-one patients (79%) had concentric hypertrophy and 20 patients (51%) had decreased LV compliance. The majority of patients with concentric hypertrophy and decreased LV compliance had normal LV internal dimensions and contractility. Six patients (15%) had ECHO results compatible with congestive cardiomyopathy. An echocardiographic distinction between congestive heart failure, decreased LV compliance, and salt and water overload in ESRD has allowed an appropriate therapeutic decision as to whether to administer cardiac glycosides or increase ultrafiltration as a treatment for pulmonary congestion. ECHO is a safe, convenient, and noninvasive method of assessing serial LV function, and it can be used to document progressive deterioration of LV function in ESRD.     

Estimation of left ventricular compliance using on-line echocardiographic automated border detection and pressure data

The end-diastolic pressure-volume relationship can be used to describe left ventricular (LV) compliance. The objective of this study was to utilize measurements of LV cavity area by echocardiographic automated border detection and pressure data to estimate the end-diastolic pressure-volume curve in an isolated heart preparation where true volume could be measured by an intraventricular balloon. Six dog hearts were excised for placement of an intraventricular balloon and a micromanometer catheter and perfused in anex vivo circuit. Mid-ventricular short-axis images were used to measure cross-sectional area by automated border detection while LV volumes were increased from 5 ml to maximal volume (30–40 ml) in each preparation. Simultaneous area and pressure data were recorded on a computer workstation through a customized interface with the ultrasound system. Three runs of varying LV volumes at 1 ml increments were performed on each of 6 hearts for a total of 1,080 simultaneous measurements. Pressure-volume and pressure-area curves were analyzed by linear regression analyses, the slope of which was used to estimate compliance. End-diastolic pressure-area and pressure-volume relationships were significantly correlated with mean r=0.97 ± 0.02 (p<0.001) from individual hearts. The slopes which served to estimate compliance of the individual pressure-area and pressure-volume curves were similar and differed by only 7±4%. A similar correlation was observed by second order regression analyses with r=0.97±0.01 (p<0.001) for pressure-area and r=0.98±0.01 (p<0.001) for pressure-volume relationships. The end-diastolic pressure-area curves may potentially be used to estimate LV compliance, although the clinical application of this method remains to be validated.     

Left ventricular involvement in arrhythmogenic right ventricular cardiomyopathy - a scintigraphic and echocardiographic study

BACKGROUND: Left ventricular involvement in arrhythmogenic right ventricular cardiomyopathy (ARVC) is a common finding in autopsy studies. In clinical studies using myocardial scintigraphy, MRI and echocardiography, contradictory results have been reported. In this study, we therefore investigated a group of 15 patients with ARVC using thallium-201 (Tl) single-photon emission tomography (SPECT) and echocardiography including assessment of mitral annular motion with M-mode and pulsed tissue Doppler. METHODS: Exercise and rest Tl-201 SPECT were performed in 15 patients with ARVC. The time from diagnosis of the disease varied from less than 1-16 years. All patients fulfilled the established diagnostic criteria for ARVC. An echocardiographic examination, including assessment of left and right ventricular motion and measurements of the mitral annulus motion with M-mode and pulsed tissue Doppler was performed in the patients and in 25 normal subjects. RESULTS: Tl-201 uptake defects in the left ventricular myocardium were present in all except one patient (93%). The uptake defects were predominantly located to the anteroseptal and basal posterior segments. Wall motion abnormalities were seen in the same segments, and in addition to this, in the septal area. In line with this, the total amplitude and the peak systolic velocity of mitral annular motion at the septal point were significantly decreased in the patients compared with the control group. CONCLUSIONS: Our data show that left ventricular involvement is common in ARVC. Tl-201 SPECT and echocardiographic abnormalities were seen not only in patients with long-lasting symptoms but also in asymptomatic patients and in those with short duration of symptoms.     

Left ventricular function (based on two-dimensional echocardiographic data) during bicycle ergometry and transesophageal electrical stimulation of the atria in patients with hypertrophic cardiomyopathy

The central hemodynamics was studied and compared in 20 patients with hypertrophic cardiomyopathy (HCMP) at rest, during bicycle ergometry (BEM) and transesophageal pacing of the atria (TEPA). According to the BEM readings, HCMP patients did not show any material differences from normals' reaction to exercise on the part of the volumetric and hemodynamic parameters as well as left ventricle contractile function. At the same time as revealed by TEPA, HCMP patients did manifest differences from normals' response in the hemodynamics and myocardial contractility. Alterations that occur in HCMP patients undergoing TEPA in response to an isolated increase of frequency of the cardiac rhythm are likely to reflect latent disorders of systolic function of the asymmetric hypertrophied left ventricle which is not capable of making adequate volumetric and functional restructure.     

Left ventricular wall motion analysis using real-time three-dimensional ultrasound

This study tested the ability of real-time 3-D (RT 3-D) echocardiography to detect and delineate regions of abnormal contraction (akinesia or dyskinesia) in a canine model of regional myocardial injury and to develop methods to simplify injury assessments. Closed chest RT 3-D scans were obtained and regional left ventricular (LV) contractile function was assessed in nine animals at baseline and after myocardial cryoinjury with a 1-cm cryoprobe. Evaluation of contractile function was based on radial shortening of LV chamber cross-sections at multiple levels. Radial length changes were analyzed using color-coded circumferential maps of the LV. Seven sets of motion maps demonstrated new areas of poorly contracting myocardium in the cryoinjured region relative to baseline. Two sets of data were excluded due to insufficient LV visualization. Motion maps derived from RT 3-D echo have the ability to detect and localize regions of abnormal LV wall motion.     

Robust real-time 3D respiratory motion detection using time-of-flight cameras

Purpose  Respiratory motion of the patient during data acquisition causes artifacts in the field of emission or computed tomography. Respiratory gating allows to track and correct these artifacts. Materials and methods  In this paper, we present a system that uses the fairly new and off-the-shelf time-of-flight (ToF) technology to compute a dense estimate of the three-dimensional respiratory motion of a patient. The work is characterized by three key contributions. The first is the employment of ToF sensors. Using ToF sensors, it is feasible to acquire a dense 3D surface model of the chest and abdomen of the patient with more than 15 frames per second. The second contribution is an algorithm to derive a surface representation which enables the estimation of the 3D respiratory motion of the patient, which is sufficient to compute 1D breathing signals for scalable specific regions of interest like chest and abdomen. The proposed data-driven algorithm models the chest and abdomen three-dimensionally by fitting distinct planes to different regions of the torso of the patient. The third contribution is the possibility to derive a sub-millimeter accurate 1D respiratory motion signal by observing the displacement of each plane. Results  Our ToF modeling approach enables marker less, real-time, 3D tracking of patient respiratory motion with an accuracy of 0.1 mm. Conclusion  Thus, our approach provides 1D breathing signals for scalable anatomical regions of interest with sufficient accuracy for artifact reduction in SPECT or X-ray angiography.     

Impact of on-line endocardial border detection on determination of left ventricular volume and ejection fraction by transthoracic 3-dimensional echocardiography.

This study was performed to determine whether use of on-line automated border detection (ABD) could reduce data analysis time for 3-dimensional echocardiography (3DE) while maintaining accuracy of 3DE in measures of left ventricular (LV) volumes and ejection fraction (EF). The study proceeded in 2 phases. In the validation phase, 20 subjects were examined with the use of 3DE and of monoplane 2-dimensional (2D) ABD. Results were compared with the reference standard of magnetic resonance imaging (MRI). In the test phase, 20 subjects underwent two 3DE studies (once with images optimized for visual border definition and once with images optimized for ABD border tracking) and a conventionally used 2D ABD study. For 3DE, volumes and EF were determined with the use of manually traced borders and ABD. Analysis times were recorded with a digital stopwatch. In the validation phase, 3DE and MRI results correlated very well (r = 0.99) without systematic differences. Comparison of 2D ABD with MRI showed good correlation for LV volumes (r >/= 0.90) and EF (r = 0.85) despite significant underestimation. For the test phase, Acoustic Quantification-optimized 3-dimensional datasets underestimated end-diastolic volume and EF relative to visually optimized 3-dimensional datasets regardless of whether borders were hand-traced or ABD was used. However, correlations ranged from r = 0.96 to r = 0.98 for LV volumes and 0.88 to 0.91 for LV EF and were superior to those for 2D ABD. Data analysis times decreased moderately with the use of ABD, but scan times increased; total study times were unchanged. Use of on-line ABD with 3DE reduces data analysis time and is more accurate than conventional monoplane 2D ABD but results in underestimation of LV volumes and EF. Additional automated postprocessing techniques may be required to obtain accurate measures, consistently using 3DE in conjunction with on-line ABD.     

Left ventricular apical diastolic collapse: an unusual echocardiographic marker of postoperative cardiac tamponade.

A 37-year-old woman was evaluated for signs and symptoms of cardiac tamponade 11 days after mitral valve replacement and tricuspid valve repair. The transthoracic echocardiogram showed a large, compartmentalized pericardial effusion that resulted in left ventricular apical diastolic collapse. Also noted were right ventricular posterior wall diastolic collapse and hemodynamic findings consistent with cardiac tamponade. This case highlights the atypical echocardiographic findings in patients with pericardial effusions after cardiac surgery.     

Improved two-dimensional echocardiographic technique for left ventricular aneurysm detection

In order to determine the sensitivity and reproducibility of a new two-dimensional echocardiographic technique for detecting left ventricular aneurysms, 16 patients suspected of having aneurysms were evaluated prospectively. Left ventricular angiography demonstrated aneurysms in 15 of the 16 patients. All 15 were detected by two-dimensional echocardiography but three were identified only in a view rotated 45 degrees clockwise from the apical four-chamber view. The analysis of 16 wall segments for each patient showed excellent agreement between two observers. Therefore, two-dimensional echocardiography, utilizing four apical views 45 degrees apart, is reliable and reproducible for the detection of left ventricular aneurysms.     

基于SPSS的生物统计数据的2D3D作图

目的结合生物统计学的软件SPSS 11.0,进行数据处理和图形结果输出,并对SPSS 11.0图表输出方式加以改进,结合MATLAB进行模拟演示,以得到更加形象并具有动态趋势的统计图。方法结合NCPP和CPP对小鼠脾脏激活作用的比较的数据,对其进行独立样本t检验,然后利用MATLAB编程进行演示。结论实现SPSS 11.0软件与MATLAB编程的相互结合,得到很形象的图形结果。