Background:Doppler echocardiographic studies in patients with β-Thalassemia Major (β-TM) had shown different patterns of left ventricle (LV) systolic and diastolic dysfunctions.Aim:This cross-sectional study was designed to study the LV systolic and diastolic function in patients with β-TM using Pulsed Doppler (PD) Echocardiogram and assess the QTc interval and QT dispersion (QTd) on 12 leads ECG.Method:All patients were evaluated clinically as well as by echocardiography and 12 leads ECG. The study included patients with β-TM (n = 38, age 15.7 ± 8.9 years), compared with an age-matched healthy control group (n = 38, age 15.9 ± 8.9 years).Results:In 38 patients with β-TM Compared with healthy control group, The QTc interval and the QTd dispersion on ECG were increased with no significant difference mode echo showed that β-TM patients have thicker LV septal wall index (0.659 ± 0.23 vs. 0.446 ± 0.219 cm/M2, P < 0.001), posterior wall index (0.659 ± 0.235 vs. 0.437 ± 0.214 cm/M2, P < 0.01), and larger LVEDD index is (3.99 ± 0.48 vs. 2.170 ± 0.57 cm/M2. P < 0.05). Pulsed Doppler showed high LV trans-mitral E wave velocity index (70.818 ± 10.139 vs. 57.532 ± 10.139, P < 0.05) and E/A ratio (1.54 vs.1.23, P < 0.01). The duration of deceleration time index (DT) and isovolumic relaxation time index (IVRT) were significantly shorter in patients with β-TM (150.234 ± 20.0.23 vs. 167.123 ± 167.123 ± 19.143 msec/M2, P < 0.01) and (60.647 ± 6.77 vs. 75.474 ± 5.83 msec/M2, P < 0.001), respectively. The tricuspid valve velocity in patients with β-TM was significantly higher than controls (2.993 ± 0.569 vs. 1.93 ± 0.471 m/sec, respectively, P < 0.01), with calculated pulmonary artery pressure of 2.4 times the control (36.0 vs. 14.8 mmHg). However, the LVEF% or fractional shortening were not significantly different.Conclusion:In this study, β-thalassemia major patients compared with controls have differences of QT dispersion and corrected QT interval that is of no statistical significance. A significantly thicker LV wall and LV diastolic filling indices are suggestive of restrictive diastolic pattern. These data indicate that LV diastolic abnormalities compromised initially in patients with β-thalassemia major.

Automatic thresholding of the gray level of an image is very useful in automated analysis of morphological Images, and it represents the first step in many applications in image understanding.Recently it was shown that by choosing the threshold as the value that maximizes the entropy of the one dimensional histogram of an image, one might be able to separate, effectively, the desired objects from the background. This approach, however, does not take into consideration the spatial correlation between the pixels in an image. Thus, the performance might degrade rapidly as the spatial interaction between pixels becomes more dominant than the gray level values. In this case, it becomes difficult to isolate the object from the background and human interference might be required.This was observed during studies that involved images of the stomach.The objective of this report is to extend the entropy -based thresholding algorithm to the two -dimensional histogram. Here, the gray level of each pixel as well as the average value of its immediate neighborhood is studied. Thus, the threshold is a vector and has two entries; the gray level of the pixel and the average gray level of its neighborhood. The vector that maximizes the two -dimensional entropy is used as the two -dimensional threshold. This method was then compared to the conventional one -dimensional entropy -based method.Several images were synthesized and others were obtained from the hospital files that represent images of the stomach of patients. it was found that the proposed approach performs better specially when the signal to noise ratio (SNR) is decreased. Both, as expected, yielded good results when the SNR was high (more than 12 db.).

Background Doppler echocardiographic studies of left ventricle (LV) systolic and diastolic function in patients with β-Thalassemia Major (β-TM) had shown different patterns of systolic and diastolic dysfunction. Aim This cross-sectional study was designed to study the LV systolic and diastolic function in patients with β-TM using Pulsed Doppler (PD) and Tissue Doppler (TD) echocardiography. Methods All patients were evaluated clinically and by echocardiography, The study included patients with β-TM (n = 38, age 15.7 ± 8.9 years) compared with an age-matched control group (n = 38, age 15.9 ± 8.9 years). The pulse Doppler indices were normalized for age and heart rate. Results Compared with control patients, M-Mode showed that patients with β-TM have thicker LV septal wall index (0.659 ± 0.23 vs. 0.446 ± 0.219 cm, P ≤ 0.001), posterior wall index (0.659 ± 0.235 vs. 0.437 ± 0.214 cm, P ≤ 0.01), and larger LVEDD index is (3.99 ± 0.48 vs. 2.170 ± 0.57 mm. P = 0.035). Pulsed Doppler showed high LV trans-mitral E wave velocity (70.818 ± 10.139 vs. 57.532 ± 10.139, p = 0.027) and E/A ratio (1.54 vs. 1.23, P ≤ 0.01). The duration of Deceleration time (DT) and isovolumic relaxation time (IVRT) were significantly shorter in patients with β-TM (150.234 ± 20.0.23 vs. 167.123 ± 19.143 msec, P ≤ 0.01) and (60.647 ± 6.77 vs. 75.474 ± 5.83 msec, P ≤ 0.001), respectively. The ratio of transmitral E wave velocity to the tissue Doppler E wave at the basal septal mitral annulus E/Em– was significantly higher in β-TM group (14.024 ± 2.29 vs. 12.132 ± 1.82, P ≤ 0.01). The Tissue Doppler systolic velocity (Sm) and the early diastolic velocity (Em) were significantly lower in β-TM group compared to control (4.31 ± 1.2 cm/s vs. 6.95 ± 2.1, P ≤ 0.01 and 4.31 ± 2.7 cm/s vs. 5.82 ± 2.5, P ≤ 0.01) respectively. The tricuspid valve velocity was significantly higher than controls (2.993 ± 0.569 vs. 1.93 ± 0.471 m/sec, respectively, P ≤ 0.01). However, the LVEF% and fractional shortening were normal with no significant difference in both groups. Conclusion In this study, patients with β-thalassemia major compared with controls, have significantly thicker LV wall, and larger LV cavity and LV diastolic filling indices suggestive of restrictive pattern with a higher tricuspid valve velocity. These data showed that left ventricle diastolic indices are compromised initially in patients with β-thalassemia major.

The problem of the phase unwrapping and the estimation of time-varying frequency is considered. The phase is first modeled as a polynomial in time. Using Lagrange interpolation polynomial approximation, for the modulo operation, where the modulus is a prime, a unique estimate for the phase is obtained. This estimate, however, is sensitive to noise. Using the method of bootstrapping, one is able to obtain good estimate even at SNR values as low as 10 dB. The method is applied to several examples, and compared to the minimum mean square polynomial fit for the phase. It is shown that the proposed approach has superior performance.

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