Short-axis Cuts Research Articles

Evaluation of the active contour and topographic watershed segmentation “assessment of the systolic ejection fraction in the left ventricular for medical assistance in 5D short axis cine MRI”

A comparative study has been depicted between the contour and topographic watershed segmentation approach for short-axis 5D cardiac sequences with MRI for medical decision. The fifth dimension has been defined as the excitation of pixels based on the gray scale around the myocardium without consideration of the morphological structure of the heart in 3D and fourth dimension (time). Three patients were performed the first is healthy, the second has a genetic disease, and the third had a heart failure syndrome for a dimension ROI = 150mm, average age is 54 years old, and mean of weight = 86 kg. A contouring and watershed segmentation algorithm for a sample of 63 Cine Fiesta MRI sequences for short-axis cuts with Matlab and its in-box toolbox complements was implemented.For a healthy patient 13.4% tolerance rate for the estimation of the stroke fraction, 6.4% for a patient with genetic disease, 8.7% error rate for a patient with heart failure symptom. The results show that the regurgitation fraction by the contour approach for a patient case with symptom of the presence of a genetic disease is 0.0335% for an aortic valve, 0.248% for a mitral valve, an error rate 0.16% for estimating this parameter for the aortic orifice with the watershed segmentation approach. In return, for a patient with suspected heart failure (stenosis or regurgitation) the regurgitation fraction is estimated by 0% for aortic valve, 1.49 e + 03% for a mitral valve, an error rate 11.76% compared to the watershed segmentation approach. The results are validated clinically. The Optimization of the topographic watershed approach with mutual information was simulated for the extraction of measurements (ejection fraction, regurgitation rate) within the left ventricle for three patient types (healthy, genetic pathology and heart failure). The results are considered interesting compared to the clinical assessment.

Understanding left ventricular hypertrabeculation/noncompaction: pathomorphologic findings and prognostic impact of neuromuscular comorbidities

ABSTRACTIntroduction: When >3 trabeculations associated with interventricular recesses are found, this is termed ‘left ventricular hypertrabeculation/noncompaction’ (LVHT). Cardiac-imaging methods detect LVHT in all ages, isolated or associated with extracardiac, especially neuromuscular disorders (NMDs). Many issues about LVHT are unclear. The review gives an update about pathomorphologic findings in patients >14 years and the role of NMDs in LVHT.Areas covered: A PubMed-search for the terms “noncompaction“ or “non-compaction“ or “hypertrabeculation“ AND “autopsy“ or ‘biopsy’ or ‘ultrastructure’ or ‘electron microscopy’ AND ‘neuromuscular’ or ‘myopathy’ or ‘neuropathy’ was carried out from 1985 to July 2018.Expert commentary: Macroanatomic (n = 65), histopathologic (n = 59) and ultrastructural (n = 7) reports were found. A comparison with echocardiography was described in 45 cases. Measurements of non-compacted and compacted layer were only given from hearts investigated in short-axis cuts after formaldehyde-fixation. Endocardial, subendocardial and interstitial fibrosis were frequent findings. When LVHT-patients were systematically investigated, a NMD was found in 80%, most frequently mitochondrial disorders, Barth syndrome, zaspopathy, and myotonic dystrophy type 1. LVHT does not seem to be a special type of cardiac involvement of NMDs. NMDs affect prognosis in LVHT as well as LVHT affects prognosis in patients with Duchenne muscular dystrophy.

Influence of fiber connectivity in simulations of cardiac biomechanics.

Personalized computational simulations of the heart could open up new improved approaches to diagnosis and surgery assistance systems. While it is fully recognized that myocardial fiber orientation is central for the construction of realistic computational models of cardiac electromechanics, the role of its overall architecture and connectivity remains unclear. Morphological studies show that the distribution of cardiac muscular fibers at the basal ring connects epicardium and endocardium. However, computational models simplify their distribution and disregard the basal loop. This work explores the influence in computational simulations of fiber distribution at different short-axis cuts. We have used a highly parallelized computational solver to test different fiber models of ventricular muscular connectivity. We have considered two rule-based mathematical models and an own-designed method preserving basal connectivity as observed in experimental data. Simulated cardiac functional scores (rotation, torsion and longitudinal shortening) were compared to experimental healthy ranges using generalized models (rotation) and Mahalanobis distances (shortening, torsion). The probability of rotation was significantly lower for ruled-based models [95% CI (0.13, 0.20)] in comparison with experimental data [95% CI (0.23, 0.31)]. The Mahalanobis distance for experimental data was in the edge of the region enclosing 99% of the healthy population. Cardiac electromechanical simulations of the heart with fibers extracted from experimental data produce functional scores closer to healthy ranges than rule-based models disregarding architecture connectivity.

CMRI morphological and functional changes of the heart in myocarditis and dilated cardiomyopathy in acute pediatric heart failure

Methods Twenty patients presented with acute heart failure. Echo and cardiac markers (including Troponin, CK, CK-MB) were performed for every patient. Patient’s age ranged from 2 mo-14years. All patients underwent CMRI study. All CMRI studies were scanned using the routine protocol to fulfill the Lake Louise criteria. The performed sequences include: 1.cine stead state free precession in axial and short axis to calculate cardiac function and volumes, 2.T2 TSE in short axis cuts for cardiac edema, the cut off value of >2.3 obtained from the ratio between myocardial muscle to skeletal muscle signals was used, 3. Short axis T1 TSE before and 5 minutes after contrast injection was used as marker of capillary leakage, and delayed myocardial enhancement (LGE) in short axis and four chamber images to show the LGE pattern. Children under 6 years were sedated with chloral hydrate.

Pathomorphologic findings in left ventricular hypertrabeculation/noncompaction of adults in relation to neuromuscular disorders

BackgroundAim of this study was to assess pathomorphologic findings (PATHO) in patients with echocardiographically (ECHO) diagnosed left ventricular hypertrabeculation/noncompaction. MethodsECHO-criteria for LVHT were: >3 trabeculations, moving synchronously with the compacted myocardium, and forming the noncompacted part of a two-layered myocardium. At autopsy, the hearts were investigated according to the pathologists' preferences. ResultsTwelve patients (2 females, age 27–81years) were included. Seven suffered from neuromuscular disorders, 5 patients were not investigated neurologically. The specimens were acquired after explantation during heart transplantation (n=1), death due to heart failure (n=6), sudden death (n=2), pneumonia (n=2) and stroke (n=1). Eight hearts were investigated without fixation and 4 after formaldehyde fixation. The hearts were opened along the long-axis, in 3 hearts additional short-axis cuts were carried out.At PATHO the trabecular meshwork was better visible in the formaldehyde-fixed hearts than in the fresh hearts. Differentiation from papillary muscles was easier on the long-axis cuts, whereas the two-layered structure was better visible on short-axis cuts. The trabecular pattern was similar in patients with neuromuscular disorders and those who did not undergo neurologic investigation. Subendocardial fibrosis was found in each case. Due to the complex three-dimensional geometry, it was impossible to count the number of trabeculations. ConclusionFormaldehyde-fixation should be performed when comparing ECHO with PATHO findings in LVHT. Long-axis as well as short-axis cuts should be carried out in order to assess the course of trabeculations and the extent of the two-layered structure. Subendocardial fibrosis in LVHT deserves further research.

Echocardiographic volumetry of the right ventricle

Please see page 15 for the article by Kovalova et al. (doi: 10.1016/j.euje.2004.04.009 ) to which this editorial pertains. Analyzing right ventricular (RV) volumes, mass and function has remained a challenge in clinical practice,1 while the relevance for obtaining accurate, reproducible data has augmented with increased numbers of patients with Grown Up Congenital Heart (GUCH) disease and acute and chronic pulmonary abnormalities.2 In comparison to the left ventricle, the right ventricle has a complex shape with different anatomical portions which contribute to the stroke volume (SV) to a variable extent. Invasively, angiography, thermodilution and conductance catheter techniques can provide absolute volumes and stroke volume, but they are inappropriate for repeated follow-up. The non-invasive modalities that are available today are echocardiography,3 nuclear (SPECT and PET), magnetic resonance and multi-slice CT (MSCT). While the general advantages and disadvantages of these modalities are very well known to the readers of the Journal, it might be worthwhile to recall the ones that are specific for the right ventricle. 2D echocardiography has difficulties to image all the different portions of the right ventricle in perpendicular views, making it difficult to adopt a simple geometric model like for the left ventricle; 3D echocardiography4,5 makes it possible to visualize the entire right ventricle and to reslice it in short axis cuts but resolution and wall delineation of these reconstructed images has only recently become acceptable; nuclear techniques6–8 suffer from …

Volume quantification of intracardiac mass lesions by transesophageal three-dimensional echocardiography

As compared with two-dimensional (2-D) transesophageal echocardiography (TEE), 3-D echocardiography now permits more realistic visualization of cardiac anatomy and of intracardiac lesions. The aim of this study was to apply newer 3-D echocardiographic techniques to quantify volumes of intracardiac masses undergoing surgical resection seen during an intraoperative TEE. The calculated volumes were compared with actual in vitro measurements of surgically resected masses. A total of 14 patients (9 men; 5 women; age range between 21 and 77 years) with intracardiac mass lesions (4 tumors: 3 left atrial myxomas and 1 mitral valve fibroelastoma, and 10 vegetations: 5 aortic valve, 3 mitral valve, 1 tricuspid and 1 pulmonary valve) were studied. Using commercially available 3-D reconstruction software (TomTec v. 4.1), the volumes of intracardiac masses were estimated using both the average rotation (rotation around the long axis, AR) and disk summation (parallel short axis cuts, DS) methods. Volumes of these lesions were also measured in vitro by water submersion. They ranged from 0.20 mL to 24 mL (mean ± SD = 8.07 ± 9.21 mL). Both 3-D TEE AR and 3-D TEE DS calculated volumes correlated excellently with in vitro measured volumes (r = 1.00 and r = 0.98, respectively, p = < 0.0001). The correlation between 3-D TEE AR and 3-D TEE DS calculated volumes was also excellent (r = 0.98, p = < 0.0001). In conclusion, the volume assessments by 3-D TEE of intracardiac mass lesions correlated well with in vitro measured volumes of surgical specimens. This technique may prove to be valuable in further defining intracardiac pathology and is a further advancement toward the application of clinically useful 3-D echocardiography. (E-mail: nanda@uab.edu)

99Tcm-methoxy-isobutyl-isonitrile SPECT to Evaluate a Perfusion Index from Regional myocardial uptake after exercise and at rest. Results of a four hour portocol in patients with coronary heart disease and in controls

In 70 patients with angiographically confirmed coronary heart disease and in 10 controls, a 4 h exercise (E) (injection of 150 MBq 99Tcm-MIBI) rest (R) (800 MBq) protocol was employed. Of these, 10 patients with 21 myocardial defects after E received a third injection 24 h after. SPECT was used to image myocardial distribution, and visual findings separated three patterns of perfusion defects after E v. R (reversible [REV], partial reversible (PREV), irreversible (IRR)). Relative regional uptake was obtained from a target-like (33 ROIs) evaluation of short-axis cuts, establishing a perfusion index (PI) by relating the defect uptake to individual maximum uptake (100%) after exercise (PIE), at rest (PIR) and the respective differences Delta PI (PIR-PIE, i.e. filling in by the second 99Tcm-MIBI injection). Visually, the sensitivity was 86% in patients or 69% in involved vessels (stenoses of greater than 33%). Vascular supply areas revealed minimal PIE values of 74.7 +/- 10.6% (control), 62.4 +/- 9.2% (REV), 46.1 +/- 7.7% (PREV) and 33.5 +/- 9.9% (IRR) (p less than 0.01). Delta PI was +13.2% or +10.1% in REV or PREV (n.s.) and +2.1% in IRR (p less than 0.01) or -0.2% in controls. PIE values did not correlate to the degree of stenosis. In areas with old myocardial infarction, the same sequence of significant decrease of PIE with reversibility occurred, independent of the patency of the supplying vessel. 33 of 35 IRR defects (94.3%) revealed PIE of less than 45%, thus predicting IRR already after the E examination. PIR values from the 4 h protocol correlated to PIR values 24 h thereafter with r = 0.94 (n = 21). 99Tcm-MIBI may be employed in a short one day E-R protocol in clinical routine. Evaluation of PI seems to be a promising tool to quantify visual defects aimed at describing the perfusional state of the terminal vascular supply area.

Three-Dimensional ROI-Based Quantification of Stress/Rest 201TI Myocardial SPECT: Presentation of Method

A semiautomated method for three-dimensional quantification of stress/rest 201Tl myocardial SPECT of the left ventricle (LV) is introduced. A total of 33 ringsegment-shaped regions of interest (ROIs) are distributed over 6 oblique (short axis cuts) double-slices (thickness 1.3 cm) from LV apex to base, commencing with 1 ROI for the apex up to 8 ROIs for the base (1-4-4-8-8-8). Within the last two double slices an additional adjacent ROI is automatically placed in the upper right quadrant to observe lung TI-uptake. Correspondence of slices for exercise and rest is achieved by adjusting the long axis outlines rebuilt from summed profiles of 15 oblique slices of each examination. Calculated numeric arrays of the extracted parameters (vitality, washout and redistribution) are displayed in a target-like two-dimensional polar fashion.

Left ventricular outflow tract obstruction in complete transposition of the great arteries with intact ventricular septum. A cross sectional echocardiography study.

The roles of posterior bulging of the interventricular septum (septal bulge) and of systolic septal mitral apposition in patients with simple transposition of the great arteries are not known. Cross sectional echocardiograms of 40 such patients were reviewed (after exclusion of those with fixed left ventricular outflow tract obstruction) and haemodynamic findings were compared with long and short axis measurements within the left ventricle. There was no significant correlation between the degree of septal bulge and systolic gradient across the left ventricular outflow tract, but septal bulge correlated weakly with systolic right ventricular pressure and inversely with pulmonary arteriolar resistance index. Systolic left ventricular outflow gradient was inversely related to the minimum systolic distance between the anterior mitral leaflet and interventricular septum. No patients without complete systolic apposition of the anterior mitral leaflet and interventricular septum had a left ventricular outflow gradient greater than 20 mm Hg. Conversely, even when cross sectional echocardiography showed apparently total obstruction of the left ventricular outflow tract at some time in systole there was often no significant gradient detected during haemodynamic study. In the short axis cuts closeness of the papillary muscles to the interventricular septum or to each other was unrelated to systolic gradient. This study shows that (a) cross sectional echocardiography can identify fixed obstruction of the left ventricular outflow tract in simple transposition of the great arteries; (b) the degree of septal bulge, unless complicated by fibrous thickening of the anterior mitral leaflet and interventricular septum, is unrelated to the gradient across the left ventricular outflow tract; (c) the absence of systolic septal/mitral apposition excludes a significant gradient at that site across the left ventricular outflow tract; and (d) papillary muscle geometry is unrelated to dynamic gradients across the left ventricular outflow in this condition.