Multipath Artifact Corrections in Ultrasonic Transmission Tomography

1982 ◽  
Vol 4 (3) ◽  
pp. 234-266 ◽  
Author(s):  
C. R. Crawford ◽  
A. C. Kak
Keyword(s):  
Refractive Index ◽  
Attenuation Coefficient ◽  
Arrival Time ◽  
Imaging Techniques ◽  
Biological Tissues ◽  
Median Filtering ◽  
Transmission Tomography ◽  
Cross Sectional ◽  
Tissue Equivalent

This paper deals with computed imaging techniques for ultrasonic transmission tomography. Cross-sectional images of the refractive index in soft biological tissues can be obtained by measuring the arrival-time of signals that propagate between two transducers. An alternative method to obtain images is to measure the attenuation in the path between the pair of transducers. In practice, images of the refractive index exhibit a better quality than images of the attenuation coefficient. In this report we have shown through computer simulation that some of the degradations in images of the attenuation coefficient are due to the existence of multiple rays that link the transmitting and the receiving transducers. This condition is known as multipath. We have demonstrated two methods to reduce the influence of multipath on reconstructions of the attenuation coefficient. The first method employs homomorphic signal processing to estimate the attenuation coefficient for one of the linking rays. The second method applies median filtering in the projection space to remove the artifacts caused by multipath. The correction techniques were tested on data obtained by scanning tissue equivalent phantoms. Results obtained indicate that the correction methods significantly improve the quality of images of the attenuation coefficient.

Differentiation between normal and tumor mammary glands with depth-resolved attenuation coefficient from optical coherence tomography

2021 ◽  
Author(s):  
Marino de Jesus Maciel ◽  
Hugo M Pereira ◽  
Sara Pimenta ◽  
Alice Miranda ◽  
Eduardo Jorge Nunes-Pereira ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Attenuation Coefficient ◽  
Light Attenuation ◽  
Biological Tissues ◽  
Mammary Glands ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Subjective Analysis ◽  
Coefficient Estimation ◽  
Cross Sectional Imaging

Abstract Optical coherence tomography (OCT) is a well-established imaging technology for high-resolution, cross-sectional imaging of biological tissues. Imaging processing and light attenuation coefficient estimation allows to further improve the OCT diagnostic capability. In this paper we use a commercial OCT system, Telesto II-1325LR from Thorlabs, and demonstrate its ability to differentiate normal and tumor mammary mouse glands with the OCT attenuation coefficient. Using several OCT images of normal and tumor mammary mouse glands (n=26), a statistical analysis was performed. The attenuation coefficient was calculated in depth, considering a slope of 0.5 mm. The normal glands present a median attenuation coefficient of 0.403 mm-1, comparatively to 0.561 mm-1 obtained for tumor mammary glands. This translates in an attenuation coefficient approximately 39 % higher for tumor mammary glands when compared to normal mammary glands. The OCT attenuation coefficient estimation eliminates the subjective analysis provided by direct visualization of the OCT images.

scholarly journals Multiscale label-free volumetric holographic histopathology of thick-tissue slides with subcellular resolution

2020 ◽  
Author(s):  
Herve Hugonnet ◽  
Yeon Wook Kim ◽  
Moosung Lee ◽  
Seungwoo Shin ◽  
Ralph H. Hruban ◽  
...  
Keyword(s):  
Refractive Index ◽  
Present Method ◽  
Imaging Techniques ◽  
Numerical Algorithms ◽  
Biological Tissues ◽  
Phase Imaging ◽  
Label Free ◽  
Volumetric Imaging ◽  
Optical Modes ◽  
Volumetric Reconstruction

ABSTRACTHistopathology relies upon the staining and sectioning of biological tissues, which can be laborious and may cause artefacts and distort tissues. Here, we demonstrate label-free volumetric imaging of thick-tissue slides, exploiting refractive index distributions as intrinsic imaging contrast. The present method systematically exploits label-free quantitative phase imaging techniques, volumetric reconstruction of intrinsic refractive index distributions in tissues, and numerical algorithms for the seamless stitching of multiple 3D tomograms and for reducing scattering-induced image distortion. We demonstrate demonstrated label-free volumetric imaging of thick tissues with the field of view of 2 mm × 1.75 mm × 0.2 mm with a spatial resolution of 170 nm × 170 nm × 1200 nm. The number of optical modes, calculated as the reconstructed volume divided by the size of the point spread function, was approximately 20 Giga voxels. We have also demonstrated that different tumour types, and a variety of precursor lesions and pathologies can be visualized with the present method.Abstract Figure

scholarly journals Bone damage after chemotherapy for lymphoma: a real-world experience

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
S. Mancuso ◽  
Dalila Scaturro ◽  
M. Santoro ◽  
G. Di Gaetano ◽  
F. Vitagliani ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Imaging Techniques ◽  
Young Patients ◽  
Complete Response ◽  
Response To Therapy ◽  
Screening Tools ◽  
Patient Treatment ◽  
Cross Sectional ◽  
Biological Variables

Abstract Background Despite recent improvements in survival due to advances in treatment, the quality of life of patients with lymphoma may be compromised by the long-term complications of chemotherapy and steroid therapy. Among these, a potentially relevant problem is bone loss and the development of fragility fractures. Aim To provide further evidence of clinical or subclinical skeletal complications in correlation with biological variables and markers of bone disease in patients with complete response to therapy. Method A cross-sectional observational study was conducted on subjects diagnosed with lymphoma with subsequent antineoplastic treatment, disease status after therapy defined as complete response disease for at least a year now. We performed: blood chemistry tests, imaging techniques and screening tools for the assessment of functional status and quality of life (SARC-F and mini-Osteoporosis Quality of Life). Results Approximately 50% of patients had osteoporosis, with a prevalence of vertebral fractures of 65.5%. In most patients, we found hypovitaminosis D and high levels of parathyroid hormone (PTH). Furthermore, a statistically significant association was observed between high PTH levels and previous lymphoma treatment. Finally, the Mini-Osteoporosis Quality of life (mini-OQLQ) questionnaire demonstrated a loss of quality of life as a consequence of the change in bone status. Conclusions Patient treatment design for personalized chemotherapy would be desirable to reduce late effects on bone. Also, early prevention programs need to be applied before starting treatment. The most benefited subpopulations could be not only elderly but also young patients.

scholarly journals Toward Better Medical Diagnosis: Tissue Optical Clearing

2020 ◽  
Vol 2 (1) ◽  
pp. 13-21
Author(s):  
Omnia Hamdy ◽  
Rania M. Abdelazeem
Keyword(s):  
Refractive Index ◽  
Medical Diagnosis ◽  
Imaging Techniques ◽  
High Refractive Index ◽  
Biological Tissues ◽  
Optical Clearing ◽  
Research Areas ◽  
Body Tissues ◽  
Deep Imaging ◽  
Tissue Optical Clearing

Reaching efficient, safe and painless medical diagnosis procedure is a very valued goal for many research areas. Despite the great advantages of using optical imaging techniques in medical diagnosis including high safety and relative simplicity, it still suffers from relatively low resolution and penetration depth in the multiple scattering mediums such as biological tissues. Therefore, researchers began to devise ways to reduce the scattering properties of the tissue, hence increasing the imaging contrast. Optical clearing concept is introduced to do this job. This technique can reduce tissues scattering properties by using high refractive index chemicals, thus making the tissue transparent by equalizing the refractive index through that medium. In this paper, theory and techniques of optical clearing method are illustrated utilizing its benefits for deep imaging of different body tissues and organs.

Numerical Ray Tracing in Media Involving Continuous and Discrete Refractive Boundaries

1980 ◽  
Vol 2 (4) ◽  
pp. 291-301 ◽  
Author(s):  
A.M. Smith ◽  
M. Goldberg ◽  
E.S.K. Liu
Keyword(s):  
Refractive Index ◽  
Medical Imaging ◽  
Boundary Conditions ◽  
Ray Tracing ◽  
Imaging Techniques ◽  
Biological Tissues ◽  
Inhomogeneous Media ◽  
Simulation Program ◽  
Digital Methods

Attempts to improve the performance of ultrasonic medical imaging techniques have led to an interest in digital methods for tracing rays through inhomogeneous media. Biological tissues involve both continuously varying and discrete refractive index boundaries. A ray tracing technique applicable for both cases is described. The performance of a simulation program is illustrated and discussed for a variety of boundary conditions.

Perceived Overprotection and Its Association With Quality of Life in Dementia

GeroPsych ◽  
2019 ◽  
Vol 32 (3) ◽  
pp. 125-134
Author(s):  
Mechthild Niemann-Mirmehdi ◽  
Andreas Häusler ◽  
Paul Gellert ◽  
Johanna Nordheim
Keyword(s):  
Quality Of Life ◽  
Patient Autonomy ◽  
Positive Association ◽  
Well Being ◽  
Negative Association ◽  
Significant Positive Association ◽  
Cross Sectional ◽  
People With Dementia ◽  
Mental Well Being

Abstract. To date, few studies have focused on perceived overprotection from the perspective of people with dementia (PwD). In the present examination, the association of perceived overprotection in PwD is examined as an autonomy-restricting factor and thus negative for their mental well-being. Cross-sectional data from the prospective DYADEM study of 82 patient/partner dyads (mean age = 74.26) were used to investigate the association between overprotection, perceived stress, depression, and quality of life (QoL). The analyses show that an overprotective contact style with PwD has a significant positive association with stress and depression, and has a negative association with QoL. The results emphasize the importance of avoiding an overprotective care style and supporting patient autonomy.

HUBUNGAN KUALITAS KEHIDUPAN KERJA TERHADAP KINERJA PERAWAT PELAKSANA

2019 ◽  
Vol 9 (4) ◽  
pp. 413-420
Author(s):  
Amella Gusty ◽  
Dachriyanus Dachriyanus ◽  
Leni Merdawati
Keyword(s):  
District Hospital ◽  
Simple Random Sampling ◽  
Work Life ◽  
Quality Of Work Life ◽  
P Value ◽  
Work Context ◽  
Cross Sectional ◽  
Quality Of Work ◽  
The Relationship

Kinerja perawat merupakan hasil yang dicapai dalam melaksanakan asuhan keperawatan di rumah sakit. Terciptanya asuhan keperawatan yang optimal sangat diperlukan dukungan dari pihak rumah sakit salah satunya adalah menciptakan kualitas kehidupan kerja baik bagi perawat. Penelitian ini bertujuan untuk mengetahui hubungan antara kualitas kehidupan kerja terhadap kinerja perawat pelaksana di RSUD Teluk Kuantan. Jenis penelitian kuantitatif dengan pendekatan cross sectional. Jumlah sampel 120 responden yang diperoleh melalui proportionate simple random sampling. Hasil penelitian menunjukkan kualitas kehidupan kerja perawat RSUD Teluk Kuantan berada pada kategori sedang, kinerja perawat berada pada kategori kurang baik. Berdasarkan analisis kedua variabel teridentifikasi bahwa tidak ada hubungan antara kualitas kehidupan kerja dengan kinerja perawat pelaksana dengan  p value 0,817. Dimensi work context merupakan komponen yang memiliki hubungan dengan kinerja perawat pelaksana dengan p value 0,008, dimensi work life  tidak berhubungan secara signifikan dengan kinerja perawat. Kesimpulan penelitian diketahui tidak ada hubungan antara kualitas kehidupan kerja dengan kinerja perawat pelaksana. Ada hubungan dimensi work context dengan kinerja perawat pelaksana. Tidak ada hubungan dimensi work life dengan kinerja perawat.   Kata kunci: kualitas kehidupan kerja, kinerja, perawat pelaksana   THE RELATIONSHIP BETWEEN THE QUALITY OF WORK LIFE AND THE PERFORMANCE OF IMPLEMENTERS NURSES   ABSTRACT Nurse performance is the result achieved in implementing nursing care in a hospital. The creation of optimal nursing care is very much needed support from the hospital, one of which is to create a good quality of work life for nurses. This study aims to determine the relationship between the quality of work life and the performance of nurses at the Kuantan District Hospital. This type of quantitative research with cross sectional approach. The number of samples of 120 respondents obtained through proportionate simple random sampling. The results showed that the quality of work life of nurses at the Kuantan District Hospital was in the medium category, the nurses' performance was in the unfavorable category. Based on the analysis of the two variables, it was identified that there was no relationship between the quality of work life with the performance of implementing nurses with a p value of 0.817. The work context dimension is a component that has a relationship with the performance of nurses implementing with p value 0.008, the dimension of work life does not significantly correlate with nurse performance. The conclusion of the research is that there is no relationship between the quality of work life and the performance of the implementing nurses. There is a relationship between the dimensions of the work context and the performance of the nurses. There is no relationship between the dimensions of work life and nurse performance.   Keywords: quality of work life, performance, implementers nurse

Glittre ADL test in eutrophic, overweight and obese elderly

2020 ◽  
Vol 21 (1) ◽  
pp. 49
Author(s):  
Augusto Baumhardt Guidoti ◽  
Ângelo Pereira Cattani ◽  
Cintia Laura De Araujo ◽  
Fernanda Beatriz Costa Delacoste ◽  
Guilherme Scotta Hentschke ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Functional Capacity ◽  
Elderly Women ◽  
Handgrip Strength ◽  
Exercise Intolerance ◽  
World Health ◽  
Chronic Obstructive ◽  
Cross Sectional ◽  
World Health Organization Quality

The Glittre ADL-test (TGlittre) has been designed and validated to measure functional capacity during daily living activities in patients with chronic obstructive pulmonary disease (COPD) but is now used in several other situations. The aim of this study was to evaluate the applicability of TGlittre in a sample of overweight and obese eutrophic elderly. This was an experimental and cross-sectional study, which included 21 elderly women, allocated by BMI, in eutrophic (n = 8), overweight (n = 6) and obese (n = 7) groups. They were assessed for functional capacity (TGlittre and 6MWT), quality of life (QOL) with the questionnaire World Health Organization Quality of Life for Older People (WHOQOL-OLD) and handgrip strength (HGS). TGlittre correlated with age (p = 0.0040) and with 6MWT (p = 0.0086), but no statistical difference was found in TGlittre's performance time and the distance covered in 6MWT between groups. TGlittre did not correlate with HGS (p = 0.1493) and WHOQOL-Old (p = 0.0905). The data obtained in the present study corroborate that TGlittre is used as a functional measurement variable in the elderly population.Keywords: aged, obesity, exercise intolerance.­­­

Hearing Outcome of Stapes Surgery in NIENT, Bangladesh

2020 ◽  
Vol 26 (1) ◽  
pp. 31-36
Author(s):  
Md Zakaria Sarkar ◽  
AHM Ferdows Nur ◽  
Utpal Kumar Dutta ◽  
Muhammad Rafiqul Islam ◽  
Debabrota Roy ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Cross Sectional Study ◽  
Surgical Trauma ◽  
Group 14 ◽  
Progressive Hearing Loss ◽  
Cross Sectional ◽  
Hearing Gain ◽  
Hearing Outcome

Objective: The aim of this study was to evaluate hearing outcome after stapedotomy in patients with Otosclerosis. Methods: This cross sectional study was carried out from July 2017 to January 2019 in National Institute of ENT, Unit V. About 22 patients with Otosclerosis were included in this study. Diagnosis of Otosclerosis was based on the history, medical status with Otoscopy, Tuning fork tests and Audiometric tests. We compiled data on the pre and post operative air-bone gap (ABG) at 0.5, 1, 2 KHZ. The ABG was Calculated using AC and BC thresholds on the same audiogram. Post operative hearing gain was then Calculated from the ABG before the operation minus the ABG of the last follow up examination Results: In this study most of the cases were age group 14-30 years (72.7%), female (54.5%). Most common symptoms was progressive hearing loss, tinnitus (77.8%).The average preoperative hearing loss in this study was (AC) was 48.31±7.68. The average post opt. hearing (AC) at follow up was 28.95±10.30 with an average hearing gain of 15.40±8.53 dB which was significant. The average pre-operative ABG was 28.99 dB ± 8.10. The average post opt. ABG was analyzed at 1 follow up showed ABG 13.18±8.09 dB which was found to be significant. Conclusion: Stapedotomy is an effective surgical procedure for the treatment of otosclerosis which leads to improvement in patient’s quality of life. A favorable hearing outcome can be obtained by the combination of experienced hands with minimal surgical trauma and appropriate surgical technique. Bangladesh J Otorhinolaryngol; April 2020; 26(1): 31-36

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