Intensity of reaction to tuberculoprotein is not related to severity of disease in patients with single organ vasculitis of the retina

Not available.

Maternal and Fetal Outcome After Cardiac Operations During Pregnancy: A Meta-Analysis

BACKGROUND

In the past, cardiac surgical procedures during pregnancy have been associated with a high risk of adverse maternal and fetal outcomes. Therefore, this meta-analysis of more recent studies was done to assess the fetomaternal risk after cardiac operations during pregnancy using cardiopulmonary bypass.

METHODS

The MEDLINE, Embase, and Cochrane library were searched to find studies from January 1, 1990, to July 31, 2016, without language restriction. We selected studies that included at least 4 women to report fetomaternal outcomes after a cardiac operation using cardiopulmonary bypass during pregnancy. Two authors independently extracted data from the selected studies. The studies were assessed for methodological qualities using the Newcastle-Ottawa Scale. The primary outcomes included maternal death and any pregnancy loss. The secondary outcomes were maternal complications and neonatal complications. Primary analysis calculated absolute risks and 95% confidence intervals (CIs) for pregnancy outcomes using the DerSimonian-Laird random effects model. Heterogeneity was assessed by I² statistic and visual plot.

RESULTS

Ten studies, including 154 women, were eligible for inclusion in this study. The patients underwent cardiac operations during pregnancy involving cardiopulmonary bypass. As calculated per 100 pregnancies, the pooled unadjusted estimate of maternal mortality was 11.2 (95% CI, 6.8 to 17.8), pregnancy loss was 33.1 (95% CI, 25.1 to 41.2), maternal complications were 8.8 (95% CI, 2.8 to 24.2), and neonatal complications were 10.8 (95% CI, 4.2 to 25.2). The risks of preterm labor and cesarean delivery were 28 per 100 pregnancies (95% CI, 15.6 to 45) and 33.8 per 100 pregnancies (95% CI, 19.1 to 52.4), respectively.

CONCLUSIONS

The fetomaternal mortality and morbidity after a cardiac operation during pregnancy are higher than that reported in the earlier literature (PROSPERO No. CRD42016047093).

Factors Associated with Physical Inactivity among Adult Urban Population of Puducherry, India: A Population Based Cross-sectional Study

INTRODUCTION

Physical inactivity is the fourth leading cause of death worldwide. Increase in physical activity decreases the incidence of cardiovascular diseases, Type 2 diabetes, stroke, and improves psychological wellbeing.

AIM

To study the level of physical inactivity among the adult population in an urban area of Puducherry in India and its associated risk factors.

MATERIALS AND METHODS

This cross-sectional study was conducted among 569 adult participants from an urban area of Pondicherry. The level of physical inactivity was measured by using WHO standard Global Physical Activity Questionnaire (GPAQ).

RESULTS

Overall prevalence of physical inactivity in our study was 49.7% (CI: 45.6-53.8). Among the physically active people, contribution of physical activity by work was 77.4%, leisure time activities were 11.6% and transport time was 11%. Both men and women were equally inactive {Physically inactive among women was 50% (CI:44.1-55.9)} and {Physically inactive among men was 49.5% (CI:43.8-55.2)}. Prevalence of physical inactivity was increasing with increasing age. Non tobacco users were two times more active than tobacco users {Adjusted Odds Ratio: 2.183 (1.175- 4.057)}. Employed were more active as compared to retired {Adjusted Odds Ratio: 0.412 (0.171-0.991)}, students {Adjusted Odds Ratio: 0.456 (0.196-1.060)}, house wives {Adjusted Odds Ratio: 0.757 (0.509-1.127)} and unemployed {Adjusted Odds Ratio: 0.538 (0.271-1.068)}. Non alcoholics were only 0.34 times as active as alcoholics.

CONCLUSION

Level of physical activity was found to be insufficient among adult urban population of Puducherry. Working adult population found to be active, that too due to their work pattern. There is a need to promote leisure time and travelling time physical activity.

Burden Among Caregivers of Children Living with Human Immunodeficiency Virus in North India

Background:

Due to wider access to and free antiretroviral therapy (ART) program, the number of children dying due to acquired immune deficiency syndrome (AIDS)-related causes has declined and the nature and duration of human immunodeficiency virus (HIV)/AIDS caregiving has also dramatically altered. The care of children living with HIV/AIDS (CLHA) places a significant additional burden on the caregivers.

Aims:

This study was conducted to assess the perceived burden among caregivers of children living with HIV in North India.

Materials and Methods:

A hospital-based cross-sectional study among 156 CLHA-caregiver dyads in North India was conducted from June 2010 to May 2011. Data were collected by using a pretested structured interview schedule. The caregiver burden was measured with a 36-item scale adapted from Burden Assessment Schedule of Schizophrenia Research Foundation (BASS). Child characteristics, caregiver characteristics, caregiving burden, the knowledge of caregivers, and issues related to health care, nutrition, education, and psychological aspects were studied.

Results:

Caregivers had a mean age of 35.9 ± 10.2 years. Women accounted for over three-fourth (76.9%) of the caregivers. Nearly two-third of them (65.4%) reported as living with HIV. The mean caregiver burden score was 68.7 ± 2.9. A majority of the caregivers reported either low or moderate burden. Standardized percentage score was high in the domains of physical and mental health, external support, patients’ behavior, and caregivers’ strategy and seemed to be comparatively less in the other domains such as support of the patient and taking responsibility.

Conclusions:

Caring of children is a universal practice but there is a need of special care for children living with HIV. The majority of caregivers who were usually the mothers perceived the burden and need to be assisted in caring for the child. Stigma and discrimination with HIV infection further increased the burden as caregivers did not disclose the HIV status to any near and dear one.

Patient and health system delays among adult smear-positive tuberculosis patients diagnosed at medical colleges of Puducherry in south India

Early diagnosis and prompt initiation of treatment are essential for an effective tuberculosis (TB) control program. This study was done to assess the extent of various delays among TB patients diagnosed at medical colleges of Puducherry. A cross-sectional study involving retrospective medical record review and prospective patient interviews was conducted in and around the union territory of Puducherry during the period 2009-10. Various delays and adjusted odds ratios (ORs) were calculated. Level of significance was determined at 95% confidence interval (CI) (P value <0.05) and all tests were two-sided. Among 216 new sputum smear-positive TB patients, 11.1% and 10.6% were smokers and alcohol users, respectively. The median patient delay, health system delay, and total delay was 37 days, 28 days, and 65 days respectively. Being a resident of Puducherry (OR = 0.39, 95% CI = 0.18-0.87) and family size of ≤5 (OR = 0.45, 95% CI = 0.21-0.97) were found as the determinants of patient delays and total delays, respectively.

Consent for audio-video recording of informed consent process in rural South India

Introduction and Objectives:

In recent times, audio-video (A-V) recording of consent process for all the study subjects entering a clinical trial has been made mandatory. A-V recording of informed consent process is a big challenge due to confidentiality and the sociocultural environment in India. It is important to find out the acceptability for A-V recording of the consent process and reasons for refusal, if any to address this new challenge.

Materials and Methods:

A descriptive survey was done among 150 residents of a rural community of South India. Acceptability for A-V recording of consent process was assessed among those who had given the informed written consent for participation in the study. An attempt to find the factors determining the refusal was also made.

Results:

More than one-third (34%) of the study subjects refused to give consent for A-V recording of consent process. Not interested in recording or don’t like to be recorded (39%) were the most common reasons to refuse for A-V recording of consent process. The refusal was higher among female and younger age-group adult subjects. Socioeconomic status was not found to be significantly associated with refusal to consent for A-V recording.

Conclusion:

Refusal for A-V recording of consent process is high in the South Indian rural population. Before any major clinical trial, particularly a field trial, an assessment of consent for A-V recording would be helpful in recruitment of study subjects.

Homomorphic wavelet thresholding technique for denoising medical ultrasound images

A novel homomorphic wavelet thresholding technique for reducing speckle noise in medical ultrasound images is presented. First, we show that the speckle wavelet coefficients in the logarithmically transformed ultrasound images are best described by the Nakagami family of distributions. By exploiting this speckle model and the Laplacian signal prior, a closed form, data-driven, and spatially adaptive threshold is derived in the Bayesian framework. The spatial adaptivity allows the additional information of the image (such as identification of homogeneous or heterogeneous regions) to be incorporated into the algorithm. Further, the threshold has been extended to the redundant wavelet representation, which yields better results than the decimated wavelet transform. Experimental results demonstrate the improved performance of the proposed method over other well-known speckle reduction filters. The application of the proposed method to a realistic US test image shows that the new technique, named HomoGenThresh, outperforms the best wavelet-based denoising method reported in [1] by more than 1.6 dB, Lee filter by 3.6 dB, Kaun filter by 3.1 dB and band-adaptive soft thresholding [2] by 2.1 dB at an input signal-to-noise ratio (SNR) of 13.6 dB.

Joint thresholding and quantizer selection for compression of medical ultrasound images in the wavelet domain

This paper introduces a simple and efficient technique for compression of medical ultrasound (US) images in the wavelet domain. The statistics of subband wavelet coefficients are modelled using the generalized Gaussian distribution (GGD). By exploiting these statistics, a uniform scalar quantizer is designed which adapts very well to the changing statistics of the signal across various subbands and scales. To increase the quantization performance, a threshold is chosen adaptively to zero-out the insignificant wavelet coefficients in the detail subbands before quantization. A distinctive feature of the proposed technique is that it unifies the two approaches to image adaptive coding: rate-distortion (R-D) optimized quantizer selection and R-D optimal thresholding, in order to increase the compression performance of the coder. The operational R-D criterion used for joint optimization is derived in the minimum description length (MDL) framework. The experimental results show that the joint R-D optimization leads to significant improvement in the compression performance of the proposed coder, named JTQ-WV, over the best state-of-the-art image coder, SPIHT. For example, the coding of US images at 0.25 bpp by JTQ-WV yields a PSNR gain of 1.0 dB over the benchmark SPIHT.

Wavelet based compression of medical ultrasound images using vector quantization

In this paper, an efficient technique for compression of medical ultrasound (US) images is proposed. The technique is based on wavelet transform of the original image combined with vector quantization (VQ) of high-energy subbands using the LBG algorithm. First, we analyse the statistical behaviour of wavelet coefficients in US images across various subbands and scales. The analysis show that most of the image energy is concentrated in one of the detail subband, either in the vertical detail subband (most of the time) or in the horizontal subband. The other two subbands at each decomposition level contribute negligibly to the total image energy. Then, by exploiting this statistical analysis, a low-complexity image coder is designed, which applies VQ only to the highest energy subband while discarding the other detail subbands at each level of decomposition. The coder is tested on a series of abdominal and uterus greyscale US images. The experimental results indicate that the proposed method clearly outperforms the JPEG2000 (Joint Photographers Expert Group) encoder both qualitatively and quantitatively. For example, without using any entropy coder, the proposed method yields a peak signal to noise ratio gain of 0.2 dB to 1.2 dB over JPEG2000 on medical US images.

Robust non-homomorphic approach for speckle reduction in medical ultrasound images

Most existing wavelet-based image denoising techniques are developed for additive white Gaussian noise. In applications to speckle reduction in medical ultrasound (US) images, the traditional approach is first to perform the logarithmic transform (homomorphic processing) to convert the multiplicative speckle noise model to an additive one, and then the wavelet filtering is performed on the log-transformed image, followed by an exponential operation. However, this non-linear operation leads to biased estimation of the signal and increases the computational complexity of the filtering method. To overcome these drawbacks, an efficient, non-homomorphic technique for speckle reduction in medical US images is proposed. The method relies on the true characterisation of the marginal statistics of the signal and speckle wavelet coefficients. The speckle component was modelled using the generalised Nakagami distribution, which is versatile enough to model the speckle statistics under various scattering conditions of interest in medical US images. By combining this speckle model with the generalised Gaussian signal first, the Bayesian shrinkage functions were derived using the maximum a posteriori (MAP) criterion. The resulting Bayesian processor used the local image statistics to achieve soft-adaptation from homogeneous to highly heterogeneous areas. Finally, the results showed that the proposed method, named GNDShrink, yielded a signal-to-noise ratio (SNR) gain of 0.42dB over the best state-of-the-art despeckling method reported in the literature, 1.73dB over the Lee filter and 1.31dB over the Kaun filter at an input SNR of 12.0dB, when tested on a US image. Further, the visual comparison of despeckled US images indicated that the new method suppressed the speckle noise well, while preserving the texture and organ surfaces.

Performance improvement of the SPIHT coder based on statistics of medical ultrasound images in the wavelet domain

This paper proposes some modifications to the state-of-the-art Set Partitioning In Hierarchical Trees (SPIHT) image coder based on statistical analysis of the wavelet coefficients across various subbands and scales, in a medical ultrasound (US) image. The original SPIHT algorithm codes all the subbands with same precision irrespective of their significance, whereas the modified algorithm processes significant subbands with more precision and ignores the least significant subbands. The statistical analysis shows that most of the image energy in ultrasound images lies in the coefficients of vertical detail subbands while diagonal subbands contribute negligibly towards total image energy. Based on these statistical observations, this work presents a new modified SPIHT algorithm, which codes the vertical subbands with more precision while neglecting the diagonal subbands. This modification speeds up the coding/decoding process as well as improving the quality of the reconstructed medical image at low bit rates. The experimental results show that the proposed method outperforms the original SPIHT on average by 1.4 dB at the matching bit rates when tested on a series of medical ultrasound images. Further, the proposed algorithm needs 33% less memory as compared to the original SPIHT algorithm.

Space-frequency quantiser design for ultrasound image compression based on minimum description length criterion

The paper addresses the problem of how the spatial quantisation mode and subband adaptive uniform scalar quantiser can be jointly optimised in the minimum description length (MDL) framework for compression of ultrasound images. It has been shown that the statistics of wavelet coefficients in the medical ultrasound (US) image can be better approximated by the generalised Student t-distribution. By combining these statistics with the operational rate-distortion (RD) criterion, a space-frequency quantiser (SFQ) called the MDL-SFQ was designed, which used an efficient zero-tree quantisation technique for zeroing out the tree-structured sets of wavelet coefficients and an adaptive scalar quantiser to quantise the non-zero coefficients. The algorithm used the statistical 'variance of quantisation error' to achieve the different bit-rates ranging from near-lossless to lossy compression. Experimental results showed that the proposed coder outperformed the set partitioning in hierarchical trees (SPIHT) image coder both quantitatively and qualitatively. It yielded an improved compression performance of 1.01 dB over the best zero-tree based coder SPIHIT at 0.25 bits per pixel when averaged over five ultrasound images.

Wavelet-based statistical approach for speckle reduction in medical ultrasound images

A novel speckle-reduction method is introduced, based on soft thresholding of the wavelet coefficients of a logarithmically transformed medical ultrasound image. The method is based on the generalised Gaussian distributed (GGD) modelling of sub-band coefficients. The method used was a variant of the recently published BayesShrink method by Chang and Vetterli, derived in the Bayesian framework for denoising natural images. It was scale adaptive, because the parameters required for estimating the threshold depend on scale and sub-band data. The threshold was computed by Ksigma2/sigma(x), where sigma and sigma(x) were the standard deviation of the noise and the sub-band data of the noise-free image, respectively, and K was a scale parameter. Experimental results showed that the proposed method outperformed the median filter and the homomorphic Wiener filter by 29% in terms of the coefficient of correlation and 4% in terms of the edge preservation parameter. The numerical values of these quantitative parameters indicated the good feature preservation performance of the algorithm, as desired for better diagnosis in medical image processing.