Search or add a thesis

Advanced Search (Beta)
Home > Motion Corrected Rapid Imaging in Cardiac Mri

Motion Corrected Rapid Imaging in Cardiac Mri

Thesis Info

Access Option

External Link

Author

Abdul Haseeb Ishtiaq Ahmed

Program

PhD

Institute

Air University

City

Islamabad

Province

Islamabad.

Country

Pakistan

Thesis Completing Year

2019

Thesis Completion Status

Completed

Subject

Computer Science

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/10459/1/Abdul%20Haseeb_Dig%20Comm_2019_Air_PRR.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727792490

Asian Research Index Whatsapp Chanel
Asian Research Index Whatsapp Chanel

Join our Whatsapp Channel to get regular updates.

Similar


Motion correction is a challenging problem in free breathing under sampled cardiac cine MRI and cardiac perfusion MRI. Respiratory motion during cine MRI acquisition can cause strong blurring artifacts in the reconstructed image. These artifacts become more prominent when use with the fast imaging reconstruction techniques like compressed sensing (CS). CS has been developed as an MRI reconstruction technique, to provide good quality sparse images from the under sampled measurements. To exploit the CS, it is needed to use CS with the motion corrected samples in cardiac cine MRI. In perfusion MRI, the under-sampling artifacts and the rapid contrast changes can cause adverse effect in the quality of reconstructed perfusion MRI. In addition to the recovery limitations, many registration techniques underperform in the presence of strong intensity changes in the cardiac perfusion MRI. In this dissertation, new reconstruction algorithms have been proposed to obtain the motion corrected cardiac cine MRI and cardiac perfusion MRI. In the first part of the dissertation, we propose two novel motion correction based CS reconstruction technique to obtain good quality images. In first technique, reconstructed cine images with the highly under sampled k-space data are achieved using motion correction based CS framework. First, image registration based similarity measure is used to bin the data in different respiratory states. Then the motion correction based CS framework is used to obtain the good quality motion free cine images. The proposed method is simple to implement in clinical settings as compared to existing motion corrected methods. The performance of the developed technique is examined using simulated data and clinical data. Results show that this method performs better reconstruction of cardiac cine images as compared to the CS reconstruction method. In the second technique, first, k-space data has been assigned to different respiratory state with the help of frequency domain phase correlation method. Then, multiple sparsity constraints have been used to provide good quality reconstructed cardiac cine images with the highly undersampled k-space measurements. The proposed method exploits the multiple sparsity constraints, in combination with demon based registration technique and a novel reconstruction technique to provide the final motion free images. The performance of the method is examined using simulated data and clinical data with different acceleration rates. In the second part of the dissertation, two novel motion correction techniques are proposed to reconstruct the motion corrected images from under sampled cardiac perfusion MRI. First technique utilizes the robust principal component analysis along with the periodic decomposition to separate the respiratory motion component that can be registered, from the unchanged contrast intensity variations. It is tested on synthetic data, simulated data and the clinically acquired data. The performance of the method is qualitatively assessed and validated by comparing manually acquired time-intensity curves of the myocardial sectors to automatically obtained curves before and after registration. In second technique, a new algorithm for robust principal component analysis is developed to separate contrast agent from the perfusion images in the presence of the acquisition noise. Then the periodic decomposition in combination with the image registration is used to remove the respiratory motion artifacts from the perfusion images. It is tested on simulated data and the clinically acquired data. The performance of the technique is stage wise compared with the existing motion correction methods.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

سلام

سلام

اَللّٰھُمَّ صَلِّ وَسَلِّمْ وَبَارِکْ عَلیٰ سَیِّدِنَا مُحَمَّد وَعلیٰ آلِہٖ وَ صَحبِہٖ
اَجمَعِین

سلام ربّ کے رسولؐ پر ہو
سلام زہرا بتولؓ پر ہو

سلام عمِّ رسولؐ پر ہو
سلام اُن کے اصول پر ہو

سلام صدیقِؓ بے ریا پر
سلام فاروقِؓ با صفا پر

سلام عثمانِؓ با حیا پر
سلام حیدرؓ شہہِ ولا پر

سلام اُمّت کی ماؤں پر ہو
سلام خضرا کی چھاؤں پر ہو

سلام شعب ِ مقاطعہ پر
سلام اہلِ مباہلہ پر

سلام ہجرت کے راہرووں پر
سلام حق کے مسافروں پر

سلام انصارؓ کی وفا پر
سلام اصحابؓ کی ادا پر

سلام اُس درسِ اوّلیں پر
سلام صُفّہ کے ہر مکیں پر

سلام بدری صحابیوں پر
سلام گردوں کے لشکروں پر

سلام عباسِؓ خیر پر ہو
سلام حمزہؓ سے شیر پر ہو

سلام عشرہ مبشّرہ پر
سلام مولا کی اِس رِضا پر

سلام طرزِ حسنؓ سخی پر
سلام صلح کی برتری پر

سلام نانا کے چین پر ہو
سلام مولا حسینؓ پر ہو

سلام کربل کے شیرِ نر پر
سلام عباسِؓ نامور پر

سلام زہراؓ کی لاڈلی پر
سلام زینبؓ کی رہبری پر

سلام اکبر سی آس پر ہو
سلام اصغر کی پیاس پر ہو

سلام شبّرؓ کے ترجماں پر
سلام قاسمؓ سے نوجواں پر

سلام زینبؓ کے لاڈلوں پر
سلام ممتا کی شفقتوں پر

سلام پیاسی سکینہ تم پر
سلام بی بی...

Inovasi Pendidikan Islam pada Masa yang Akan Datang: Penggabungan Madrasah dan Sekolah Pilihan

Pendidikan Islam menjadi pilihan masa depan, dan menjadi rujukan dalam mengembangkan potensi peserta didik dan embrio peradaban dunia, kemajuan peradaban Islam lahir dari pendidikan Islam yang berkualitas. Oleh karena itu, pendidikan agama Islam harus dikelola secara profesional, berbasis saintek dan berkualitas. Sistem pendidikan Islam mendesak untuk direformulasi sesuai dengan dinamika zaman, kebutuhan pasar, dan berbasis kearifan lokal, sehingga melahirkan ulama dan cendekiawan saintis yang unggul. Metodologi yang digunakan dalam penelitian ini adalah penelitian kualitatif, penelitian ini mengambil lokasi di Kota Pekanbaru, dengan sampel SMUN 10 dan MAN 3. Hasil penelitian ini adalah integrasi sistem pendidikan, baik sistem pendidikan sekolah unggulan maupun sistem pendidikan Madrasah, relevan dilakukan sebagai upaya mencari model pendidikan Islam yang ideal dan riil di era globalisasi.  

An Assessment of Inland Destructive Fishing Practices in District Charsadda, Pakistan

Inland fishing is common in Pakistan and is a vital component of human diet, source of food security, livelihoods and recreation. Despite being so much important, the freshwater fisheries have not yet been given proper attention in Pakistan. The fish stock in the rivers is continuously on the decline and destructive fishing practices on the increase, leading to serious decline of fishes in the inland rivers of the study area. The monetary losses for the neighboring communities and society resulting from such damage are more than the direct individual benefits made by the users of these destructive methods. Fishermen and people residing near water bodies are the main actors in fishery related issues and their knowledge and perceptions about destructive fishing practices and conservation of fishery resources are valuable. Therefore, this study was conducted in district Charsadda Khyber Pakhtunkhwa province of Pakistan to pinpoint the major socioeconomic drivers of destructive fishing practices, and its impact on fishermen livelihoods and fish consumption. Data was collected through a household survey from 286 households from nine fishermen concentrated villages of district Charsadda, using two stage cluster sampling method. The households were divided into three groups (Type I, Type II and Type III) in order to distinguish between households based on different characteristics. The fisher‘s socio-economic characteristics were analyzed through simple statistics such as frequencies, percentages, averages and standard deviations. Stepwise multiple linear regression models were used to identify the drivers of destructive fishing practices, multiple regression for factors affecting fish consumption and Livelihood Asset Pentagon for impact of destructive fishing practices on fishermen livelihoods.The stepwise multiple linear regression model revealed that out of a total of seven variables five were negatively and two positively correlated to DFPs. The results of livelihood asset pentagon revealed that fishermen livelihood assets deteriorated in the last fifteen years due to reduction in the size and amount of fishes in the rivers. The findings of this study led to specific recommendations for combating the problems of DFPs and policy measures to reduce pressure on fishery resources in the area, such as awareness and environmental education, creation of alternative livelihoods opportunities and involvement of community in the conservation of natural resources.