Mediscan Systems

Chennai, India

Mediscan Systems

Chennai, India

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Tuz K.,Albany Medical College | Bachmann-Gagescu R.,University of Zürich | O'Day D.R.,University of Washington | Hua K.,Albany Medical College | And 25 more authors.
American Journal of Human Genetics | Year: 2014

Joubert syndrome (JBTS) is a recessive ciliopathy in which a subset of affected individuals also have the skeletal dysplasia Jeune asphyxiating thoracic dystrophy (JATD). Here, we have identified biallelic truncating CSPP1 (centrosome and spindle pole associated protein 1) mutations in 19 JBTS-affected individuals, four of whom also have features of JATD. CSPP1 mutations explain ∼5% of JBTS in our cohort, and despite truncating mutations in all affected individuals, the range of phenotypic severity is broad. Morpholino knockdown of cspp1 in zebrafish caused phenotypes reported in other zebrafish models of JBTS (curved body shape, pronephric cysts, and cerebellar abnormalities) and reduced ciliary localization of Arl13b, further supporting loss of CSPP1 function as a cause of JBTS. Fibroblasts from affected individuals with CSPP1 mutations showed reduced numbers of primary cilia and/or short primary cilia, as well as reduced axonemal localization of ciliary proteins ARL13B and adenylyl cyclase III. In summary, CSPP1 mutations are a major cause of the Joubert-Jeune phenotype in humans; however, the mechanism by which these mutations lead to both JBTS and JATD remains unknown. © 2014 The American Society of Human Genetics.


Hemalatha R.,Knowledge Institute of Technology | Santhiyakumari N.,Knowledge Institute of Technology | Suresh S.,Mediscan Systems
International Conference on Signal Processing and Communication Engineering Systems - Proceedings of SPACES 2015, in Association with IEEE | Year: 2015

In the decade of technological advancement, the image processing techniques has made it possible to save lives of several beings. The diagnosis of cardiovascular involved in complex procedures whereas the analysis of blood vessels carried out. The image segmentation technique is used to eliminate such complexities in Ultrasound carotid image diagnosis. In this paper the implementation of segmented intima-media interface of the common carotid artery image has been proposed in real time Virtex Field Programmable Gate Array. The intima-media interface has been extracted using threshold segmentation technique. The pre-processing step is used to remove speckles present in the ultrasound carotid image and the morphological techniques can be used in segmentation algorithm with the aid of Aphelion Dev software. The resulting image has been implemented in Virtex which provides minimum hardware resources and low power consumption and is desirable for real time medical applications and analysis. © 2015 IEEE.


Madian N.,KS Rangasamy College of Technology | Jayanthi K.B.,KS Rangasamy College of Technology | Suresh S.,Mediscan Systems
2015 IEEE Global Conference on Signal and Information Processing, GlobalSIP 2015 | Year: 2015

Cytogenetics deals with the study of human chromosomes. This helps in detecting birth defects. Segmentation of overlapped chromosomes in metaphase images is very important in chromosome analysis. This becomes a complex task when more than one overlap occurs in the chromosomes mainly due to the non rigid nature of the chromosomes. This paper proposes an algorithm for identification of overlap zone which is the important step in segmentation of overlapping chromosomes without human intervention. Outer contour of the chromosomes is obtained including the overlapping zones. Then the curvature function is used to identify the concave and convex points. These concave points are used in finding the overlap zones. More than one overlap is identified correctly. G-band metaphase chromosome images are taken for analysis. The algorithm is robust. It is tested on more than 350 images with various number and degree of overlaps. The overall accuracy of the algorithm is 96%. © 2015 IEEE.


Karthikeyan G.,Womens Center | Jagadeesh S.,Mediscan Systems | Seshadri S.,Mediscan Systems | Haberle J.,University Childrens Hospital
Indian Pediatrics | Year: 2013

Citrullinemia type 1 was diagnosed by tandem mass spectrometry in a full term male neonate who presented with an acute catastrophic collapse on the 3rd day of life. Both parents were identified to be carriers for the exon 15 p Gly390Arg mutation in the argininosuccinate synthetase gene located at chromosome 9q34.1. Chorionic villus sampling and prenatal genetic testing in the subsequent pregnancy revealed an affected fetus resulting in termination of pregnancy. © 2013 Indian Academy of Pediatrics.


Selvan S.,Anna University | Kavitha M.,Anna University | Shenbagadevi S.,Anna University | Suresh S.,Mediscan Systems
Journal of Computer Science | Year: 2010

Problem statement: Elastography is developed as a quantitative approach to imaging linear elastic properties of tissues to detect suspicious tumors. We propose an automatic feature extraction method in ultrasound elastography and echography for characterization of breast lesions. Approach: The proposed algorithm was tested on 40 pairs of biopsy proven ultrasound elastography and echography images of which 11 are cystic, 16 benign and 13 malignant lesions. Ultrasound elastography and echography images of breast tissue are acquired using Siemens (Acuston Antares) ultrasound scanner with a 7.3 MHz linear array transducer. The images were preprocessed and subjected to automatic threshold, resulting in binary images. The contours of a breast tumor from both echographic and elastographic images were segmented using level set method. Initially, six texture features of segmented lesions are computed from the two image types followed by computing three strain and two shape features using parameters from segmented lesions of both elastographic and echographic images. Results: These features were computed to assess their effectiveness at distinguishing benign, malignant and cystic lesions. It was found that the texture features extracted from benign and cystic lesions of an elastogram are more distinct than that of an ultrasound image .The strain and shape features of malignant lesions are distinct from that of benign lesions, but these features do not show much variation between benign and cystic lesions. Conclusion: As strain, shape and texture features are distinct for benign, malignant and cystic lesions, classification of breast lesions using these features is under implementation. © 2010 Science Publications.


Kavitha M.,Indian Institute of Technology Madras | Ramasubba Reddy M.,Indian Institute of Technology Madras | Suresh S.,Mediscan Systems
Journal of Medical Imaging and Health Informatics | Year: 2014

Ultrasound Elastography Imaging (UEI) is one of the in vivo stiffness measurement methods for human tissues. Since stiffness is highly correlated with pathology of tissue, measurement of stiffness could be helpful in diagnosis of cancer in breast, thyroid, prostate and liver. UEI involves, applying a small external compression on tissue of interest and then measuring the deformation using ultrasound imaging. Contrast transfer efficiency (CTE) is defined as the ability of any imaging technique to represent the actual modulus ratio in to a reasonable image contrast. In this work, a study was carried out to investigate the contrast transfer efficiency of ultrasound Elastography Imaging (UEI) in characterizing different classes of inclusions using simulated tissue mimicking phantoms. Using finite element method, phantom was simulated with embedded inclusions of varying stiffness to represent different stages of cancer. Results show that mean CTE is comparatively better for low modulus contrast lesions than high modulus contrast lesions. Results are validated with clinical images and have good agreement with literature also. Copyright © 2014 American Scientific Publishers All rights reserved.


Manickam K.,Indian Institute of Technology Madras | Machireddy R.R.,Indian Institute of Technology Madras | Seshadri S.,Mediscan Systems
Ultrasonics | Year: 2014

A pilot study was carried out to investigate the performance of ultrasound stiffness imaging methods namely Ultrasound Elastography Imaging (UEI) and Acoustic Radiation Force Impulse (ARFI) Imaging. Specifically their potential for characterizing different classes of solid mass lesions was analyzed using agar based tissue mimicking phantoms. Composite tissue mimicking phantom was prepared with embedded inclusions of varying stiffness from 50 kPa to 450 kPa to represent different stages of cancer. Acoustic properties such as sound speed, attenuation coefficient and acoustic impedance were characterized by pulse echo ultrasound test at 5 MHz frequency and they are ranged from (1564 ± 88 to 1671 ± 124 m/s), (0.6915 ± 0.123 to 0.8268 ± 0.755 db cm-1 MHz-1) and (1.61×106 ± 0.127 to 1.76 × 106 ± 0.045 kg m-2 s-1) respectively. The elastic property Young's Modulus of the prepared samples was measured by conducting quasi static uni axial compression test under a strain rate of 0.5 mm/min upto 10 % strain, and the values are from 50 kPa to 450 kPa for a variation of agar concentration from 1.7% to 6.6% by weight. The composite phantoms were imaged by Siemens Acuson S2000 (Siemens, Erlangen, Germany) machine using linear array transducer 9L4 at 8 MHz frequency; strain and displacement images were collected by UEI and ARFI. Shear wave velocity 4.43 ± 0.35 m/s was also measured for high modulus contrast (18 dB) inclusion and X.XX m/s was found for all other inclusions. The images were pre processed and parameters such as Contrast Transfer Efficiency and lateral image profile were computed and reported. The results indicate that both ARFI and UEI represent the abnormalities better than conventional US B mode imaging whereas UEI enhances the underlying modulus contrast into improved strain contrast. The results are corroborated with literature and also with clinical patient images. © 2013 Elsevier B.V. All rights reserved.


Manickam K.,Indian Institute of Technology Madras | Machireddy R.R.,Indian Institute of Technology Madras | Seshadri S.,Mediscan Systems
Journal of the Mechanical Behavior of Biomedical Materials | Year: 2014

Pathological changes of the body have been observed to change the mechanical properties of soft tissue types which can be imaged by ultrasound elastography. Though initial clinical results using ultrasound elastography in detection of tumors are promising, quantification of signal to noise ratio, resolution and strain image patterns are the best achieved under a controlled study using phantoms with similar biomechanical properties of normal and abnormal tissues. The purpose of this work is to characterize the biomechanical properties of agar based tissue mimicking phantoms by varying the agar concentration from 1.7 to 6.6% by weight and identify the optimum property to be used in classification of cancerous tissues. We performed quasi-static uniaxial compression test under a strain rate of 0.5. mm/min up to 15% strain and measured Young's modulus of phantom samples which are from 50. kPa to 450. kPa. Phantoms show nonlinear stress-strain characteristics at finite strain which were characterized using hyperelastic parameters by fitting Neo-Hookean, Mooney Rivlin, Ogden and Veronda Westmann models. We also investigated viscoelastic parameters of the samples by conducting oscillatory shear rheometry at various precompression levels (2-5%). Loss modulus values are always less than storage modulus which represents the behavior of soft tissues. The increase in agar concentration increases the shear modulus of the samples as well as decreases the linear viscoelastic region. The results suggest that dynamic shear modul are more promising than linear and nonlinear elastic modul in differentiation of various classes of abnormal tissues. © 2014 Elsevier Ltd.


Kumar K.,Indian Institute of Technology Madras | Andrews M.E.,Indian Institute of Technology Madras | Jayashankar V.,Indian Institute of Technology Madras | Mishra A.K.,Indian Institute of Technology Madras | Suresh S.,Mediscan Systems
IEEE Transactions on Instrumentation and Measurement | Year: 2010

Many ailments and/or malfunctions of the body have been observed to change the viscous behavior and elastic properties of biological soft tissues. The technique of elastography has evolved to image such properties. The clinical evidence gathered during studies involving elastography to identify cancerous lesions is very promising. However, the quantification of the resolution and specificity of elastography is best achieved under a controlled study using tissue-mimicking phantoms. One challenge is to reproduce viscoelastic behavior in phantoms as observed in biological tissues. In this paper, polyacrylamide gel based tissue-mimicking phantoms have been developed to experimentally study the role of viscoelastic properties in a controlled manner. To measure the Young's modulus, the phantoms were subjected to linear loading, and the stressstrain relationship is deduced therefrom. It is seen that the phantoms show hysteresis behavior. The viscoelastic properties of these phantoms were measured by subjecting the samples to cyclic loading. Normal forces during this process of loading were also measured as a measure of sample elasticity. To emulate the normal and pathological lesions, samples were prepared with varying concentration of monomer and studied. Three models, namely, Maxwell, KelvinVoigt (KV), and KelvinVoigt fractional derivative (KVFD), were chosen to fit the experimental data. Of these, the KVFD model was found to be best fitting for the experimental data obtained. Results indicate that stiffer samples exhibit large variations in the storage modulus when the precompression levels are altered. © 2006 IEEE.


Joseph J.,Indian Institute of Technology Madras | Thomas E.A.,Indian Institute of Technology Madras | Sivaprakasam M.,Indian Institute of Technology Madras | Suresh S.,MediScan Systems
Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS | Year: 2013

Evaluation of arterial compliance is significant in cardiovascular diagnosis for early detection of coronary heart disease. We present ARTSENS, an image-free system for non-invasive evaluation of arterial compliance in-vivo. The system utilizes a single element ultrasound probe with intelligent measurement algorithms to ensure accurate evaluation of local arterial compliance without an image. The ability of the system to detect artery anatomy and measure compliance was verified by in-vivo measurements conducted on 106 subjects. The accuracy of compliance estimates were evaluated by comparison with a state of art imaging system. The measurements made using ARTSENS showed strong correlation with those made using the imaging system. The ability of ARTSENS to detect age-related trends in arterial compliance was also investigated. © 2013 IEEE.

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