Download or read book Visual grading evaluation of reconstruction methods and dose optimisation in abdominal Computed Tomography written by Bharti Kataria and published by Linköping University Electronic Press. This book was released on 2019-10-15 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its introduction in the 1970’s CT has emerged as a modality of choice because of its high sensitivity in producing accurate diagnostic images. A third of all Computed Tomography (CT) examinations are abdominal CTs which deliver one of the highest doses among common examinations. An increase in the number of CT examinations has raised concerns about the negative effects of ionising radiation as the dose is cumulative over the life span of the individual. Image quality in CT is closely related to the radiation dose, so that a certain dose with an associated small, but not negligible, risk is a prerequisite for high image quality. Typically, dose reduction in CT results in higher noise and a decrease in low contrast resolution which can be detrimental to the image quality produced. New technology presents a wide range of dose reduction strategies, the latest being iterative reconstruction (IR).The aim of this thesis was to evaluate two different classes of iterative reconstruction algorithms: statistical (SAFIRE) and model-based (ADMIRE) as well as to explore the diagnostic value of a low-dose abdominal CT for optimisation purposes. This thesis included a total of 140 human subjects in four image quality evaluation studies, three of which were prospective studies (Papers I, II and IV) and one retrospective study (Paper III). Visual grading experiments to determine the potential dose reductions, were performed with pairwise comparison of image quality in the same patient at different tube loads (dose) and reconstructed with Filtered back projection (FBP) and SAFIRE strength 1 in a low-dose abdominal CT (Paper I) and FBP and ADMIRE strengths 3 and 5 in a standard dose abdominal CT (Paper II). Paper IV evaluated the impact of slice thicknesses in CT images reconstructed with ADMIRE strengths 3 and 5 when comparing multiplanar reconstruction (MPR) formatted images in a standard dose abdominal CT. Paper III, on the other hand, was an absolute assessment of image quality and pathology between the three phases of a CT Urography (CTU) protocol to explore the diagnostic value of low-dose abdominal CT. The anonymised images were displayed in random order and image quality was assessed by a group of radiologists using image quality criteria from the “European guidelines of quality criteria for CT”. The responses from the reviewer assessment were analysed statistically with ordinal logistic regression i.e. Visual Grading Regression (VGR). Results in Paper I show that a small dose reduction (5-9 %) was possible using SAFIRE strength 1and indicated the need for further research to evaluate the dose reduction potential of higher strengths of the algorithm. In Paper II a 30% dose reduction was possible without change in ADMIRE algorithm strength as no improvement in image quality was observed between tube loads 98- and 140 mAs. When comparing tube loads 42 and 98 mAs, further dose reduction was possible with ADMIRE strength 3 (22-47%). However, for images reconstructed with ADMIRE strength 5, a dose reduction of 34-74% was possible for some, but not all image criteria. Image quality in low-contrast objects such as the liver parenchyma, was affected and a decline in diagnostic confidence was observed. Paper IV showed potential dose reductions are possible with increasing slice thickness from 1 mm to 2 mm (24-35%) and 1 mm to 3mm (25-41%). ADMIRE strength 3 continued to provide diagnostically acceptable images with possible dose reductions for all image criteria assessed. Despite objective evaluations showing a decrease in noise and an increase in contrast to noise ratio, ADMIRE strength 5 had diverse effects on the five image criteria, depending on slice thickness and further dose reductions were limited to certain image criteria. The findings do not support a general recommendation to replace ADMIRE3 with ADMIRE5 in clinical abdominal CT protocols. Paper III studied another aspect of optimisation and results show that visualisation of renal anatomy was as expected in favour of the post-contrast phases when compared to the native phase. Assessment of pathology showed no significant differences between the three phases. Significantly higher diagnostic certainty for renal anatomy was observed for the post-contrast phases when compared to the native phase. Significantly high certainty scores were also seen for the nephrographic phase for incidental findings. The conclusion is that a low-dose series seems to be sufficient as a first-line modality in certain patient groups. This thesis clinically evaluated the effect of IR in abdominal CT imaging and estimated potential dose reductions. The important conclusion from papers I, II and IV is that IR improves image quality in abdominal CT allowing for some dose reductions. However, the clinical utility of the highest strength of the algorithm is limited to certain criteria. The results can be used to optimise the clinical abdominal CT protocol. The conclusion from paper III may increase clinical awareness of the value of the low-dose abdominal protocol when choosing an imaging method for certain patient groups who are more sensitive to radiation. Datortomografi (DT) används i allt större omfattning vid bilddiagnostik och ger en viss stråldos till patienten. DT är en viktig, snabb och patientvänlig undersökningsteknik. En fördel med denna teknik är att bildmaterialet kan rekonstrueras i olika format för att åskådliggöra anatomin på bästasätt beroende på vilken frågeställning som ska besvaras. Joniserande strålning från dessa undersökningar anses öka risken för negativa effekter även om risken för den enskilde patient är mycket liten. Antalet datortomografiundersökningar ökar från år till år vilket kan leda till ökade stråldoser tillbefolkningen. Optimering av undersökningsteknik och val av undersökning för att minska negativa effekter av röntgenstrålning är därför nödvändig. Det övergripande målet med avhandlingen var att utvärdera bildkvalitetvid en DT-undersökning av buken (då dessa medför en av de högstastråldoserna bland de vanliga röntgenundersökningarna), att kvantifieramöjlig stråldosminskning med hjälp av iterativa rekonstruktionsalgoritmer och att utvärdera diagnostiska värdet av lågdosundersökningsteknik vid DT-buk. Av de fyra delstudierna var delarbeten I, II och IV prospektiva och delarbete III retrospektivt. För de prospektiva studierna, samlades bildmaterial in vid en kliniskberättigad undersökning av lågdos-DT av buken (delarbetet I), eller standarddos-DT av buken (delarbetet II och IV). Bilder rekonstruerades meden standard bildrekonstruktionsalgoritm, filtrerad återprojektion (FBP), och med styrka 1 av den iterativa algoritmen SAFIRE (delarbetet I). I delarbeten II och IV, gjordes bildrekonstruktioner med FBP och med styrka 3 och 5 av den iterativa algoritmen ADMIRE. Avidentifierade bildmaterialför varje patient visades parvis i slumpmässig ordning för ett antal granskare och bildkvaliteten bedömdes med hjälp av europeiska bildkriterier. I den retrospektiva studien, delarbete III, hämtades bildmaterialet från utförda DT-urografiundersökningar från bildarkivet. För varje undersökning visades bilder från varje fas i DT-urografiundersökningen separat i slumpmässig ordning. För samtliga delarbeten, hämtades bildkriteriernafrån ”European Guidelines of Quality Criteria for CT” och modifierades för att passa till varje studie. Granskarnas bedömning analyserades med ordinal logistisk regression så kallad visual grading regression (VGR). Resultat från delarbetet I visade att det fanns en signifikant inverkan av dos (p <0,001) och rekonstruktionsalgoritm (p <0,01) på samtliga bildkriterier, med en beräknad möjlig dosminskning på 5–9%. Delarbetet II visade att rekonstruktionsalgoritmen ADMIRE förbättrar bildkvaliteten i jämförelse med FBP. ADMIRE styrka 3 tillåter en dosminskning mellan 22–47% för samtliga bildkriterier medan ADMIRE styrka 5 tillåter en dosminskning mellan 34–74% för nästan alla bedömda bildkriterier utom återgivning av leverns parenkym. Ett mycket oväntat resultat var att bildkvalitén för 70% dosnivå bedömdes som högre eller likvärdig med 100% dosnivå, vilket innebar att stråldosen kan sänkas med 30% utan förändring i algoritm eller styrka. Resultaten av delarbete III visade att avbildning av njuranatomi var som förväntat för varje fas med fördel för kontrastuppladdningsfaserna jämfört med den nativa fasen. Detta var inte ett oväntat resultat eftersom DT-urografiprotokollet är utformat för att visualisera njuranatomi på bästa möjliga sätt. Vid bedömning av patologiska fynd, erhölls dock små och ickesignifikanta skillnader mellan faserna. Däremot noterades signifikant högre bedömningssäkerhet för patologi i njurarna för de kontrast förstärkta faserna jämfört med nativfasen, och endast för bifynd signifikant högre poäng för parenkymfasen. Delarbete IV visade att styrka 5 jämfört med styrka 3 av den iterativa rekonstruktionsalgoritmen, har olika effekter på bedömningen av bildkvalitetskriterierna. Ökning av MPR-snittjocklek från 1 mm till 2 mm eller 3mm, ger en förbättring i bildkvalité, vilket möjliggör en viss dosreduktion. Den kliniska användbarheten av ADMIRE styrka 5 är begränsad, medan ADMIRE styrka 3 levererar bättre bildkvalitet för samtliga undersökta bildkriterier vid datortomografiundersökning av buken. Den viktigaste slutsatsen av delarbeten I, II och IV är att iterativa rekonstruktionsalgoritmer förbättrar bildkvalitet jämfört med FBP för samma stråldos och en dosminskning är möjlig. Detta kan användas för att optimera det kliniska DT-bukundersöknings protokoll. Slutsatsen för delarbetet III var att en lågdos-DT-bukundersökning är ett av många dosreduceringsalternativ, som möjligen kan användas för att minska strålningsbördan hos vissa patientgrupper som är mer känsliga för röntgenstrålning.

Download or read book Dose Optimization in Digital Radiography and Computed Tomography written by Euclid Seeram and published by Springer Nature. This book was released on 2023-02-21 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses radiation protection of patients having digital radiography and computed tomography (CT) examinations. The literature on radiation doses to patients from these two modalities have reported that the doses to patients are high. As a result, the radiology community has focused on methods and procedures to keep these doses as low as reasonably achievable (ALARA) without compromising the diagnostic image quality. This book outlines the motivation for dose optimization in radiology, identifies and describes the ICRP principle of optimization, outlines the factors affecting the dose in digital radiography and in CT, and identifies and describes strategies used in digital radiography and in CT for dose optimization. This book is intended for all those working in digital radiography and CT environments including radiological technologists, and radiographers, radiologists, biomedical engineering technologists, and student medical physicists. It is best used as a supplement to radiologic science textbooks, and in particular, radiation protection textbooks. Furthermore, this book lays the foundations for students and practitioners engaged in research on dose reduction and dose optimization in radiology. · Provides practical and useful methods for optimization of doses from digital radiography and CT · Describes the International Commission on Radiological Protection (ICRP) principle of optimization · Outlines the factors affecting the dose in digital radiography and in computed tomography

Download or read book Gastrointestinal Imaging written by Angela D. Levy and published by Rotations in Radiology. This book was released on 2015 with total page 761 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents a comprehensive review of gastrointestinal pathologies commonly encountered by practising radiologists and residents in training. The chapters are organised by organ system and include the pharynx and esophagus, stomach, small bowel, appendix, colon, anorectum, liver, gallbladder, bile ducts, pancreas, spleen, peritoneum, mesentery, and abdominal wall, and one on multisystem disorders. The book offers a guided approach to imaging diagnosis with examples of all imaging modalities complimented by the basics of technique and interpretation and the nuances necessary to reach the best diagnosis.

Download or read book MDCT A Practical Approach written by S. Saini and published by Springer Science & Business Media. This book was released on 2007-03-14 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes current examination techniques and advanced clinical applications of state-of-the-art multidetector computed tomography (MDCT) scanners. There are contributions from several distinguished radiologists and clinicians. Each chapter is written from a practical perspective, so that radiologists, residents, medical physicists, and radiology technologists can obtain relevant information about MDCT applications.

Download or read book Computed Tomography for Technologists Exam Review written by Lois Romans and published by Lippincott Williams & Wilkins. This book was released on 2018-07-23 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher's Note: Products purchased from 3rd Party sellers are not guaranteed by the Publisher for quality, authenticity, or access to any online entitlements included with the product. Computed Tomography for Technologists: Exam Review, Second Edition, is intended to be used as a companion to Computed Tomography for Technologists: A Comprehensive Text, Second Edition, and as a review of computed tomography on its own. This is an excellent resource for students preparing to take the advanced level certification exam offered by The American Registry of Radiologic Technologists (ARRT).

Download or read book Cumulated Index Medicus written by and published by . This book was released on 1978 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Artificial Intelligence in Medical Imaging written by Erik R. Ranschaert and published by Springer. This book was released on 2019-01-29 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a thorough overview of the ongoing evolution in the application of artificial intelligence (AI) within healthcare and radiology, enabling readers to gain a deeper insight into the technological background of AI and the impacts of new and emerging technologies on medical imaging. After an introduction on game changers in radiology, such as deep learning technology, the technological evolution of AI in computing science and medical image computing is described, with explanation of basic principles and the types and subtypes of AI. Subsequent sections address the use of imaging biomarkers, the development and validation of AI applications, and various aspects and issues relating to the growing role of big data in radiology. Diverse real-life clinical applications of AI are then outlined for different body parts, demonstrating their ability to add value to daily radiology practices. The concluding section focuses on the impact of AI on radiology and the implications for radiologists, for example with respect to training. Written by radiologists and IT professionals, the book will be of high value for radiologists, medical/clinical physicists, IT specialists, and imaging informatics professionals.

Download or read book MDCT Protocols written by Andrea Laghi and published by Springer Science & Business Media. This book was released on 2012-04-23 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multidetector-row computed tomography (MDCT) has become a fundamental imaging technique for the study of many anatomical districts in different clinical situations, as it provides a fast, reliable, and accurate simultaneous evaluation of different organs, including parenchyma, hollow viscera, vessels, and bony structures. It has also equipped the radiologist with the ability to explore areas that in the last decade were largely ignored by CT, especially the coronary arteries and the colon, and to limit invasive diagnostic tests (e.g., catheter angiography) to those cases in which interventional procedures are required. The examination quality and the consequent diagnostic accuracy of MDCT are the results of an optimized study technique, which nonetheless needs to be adapted to the particular clinical situation of the patient, while bearing in mind the radiation exposure. Another fundamental parameter in the optimization of MDCT is the protocol for the intravenous injection of iodinated contrast material; in these studies, multiple variables, some modifiable by the operator and others patient-dependent, must be considered based on the aims of maximizing arterial and venous enhancements whilst minimizing the dose of iodine injected, saving money, and increasing patient safety. Through the presentation of cases addressing different anatomical regions and various clinical indications, including emergency and neuro-imaging, this volume seeks to provide the general radiologist and trainee specialist with a guide to the main study protocols to be implemented in order to optimize examination quality and, consequently, facilitate the diagnostic process.

Download or read book Adaptive Radiation Therapy written by X. Allen Li and published by CRC Press. This book was released on 2011-01-27 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern medical imaging and radiation therapy technologies are so complex and computer driven that it is difficult for physicians and technologists to know exactly what is happening at the point-of-care. Medical physicists responsible for filling this gap in knowledge must stay abreast of the latest advances at the intersection of medical imaging an

Download or read book Multislice CT written by M.F. Reiser and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: The introduction of multidetector spiral CT into clinical practice is without any doubt one of the most important technical developments in the field of computed tomography in general, and spiral CT in particular, in recent years. Indeed, multislice CT technology, based on the spiral CT technique invented by W. Kalender almost 20 years ago, has opened immense and totally new perspectives for better utilisation of contrast medium during the examination, for optimal multiplanar reconstruction and for increased patient throughput. The potential applications, more specifically in the area of CT angiography of the brain and the heart and vessels, are most interesting and definitely contribute to better patient care as well as to more effi cient utilisation of equipment. These exciting new clinical applications explain the keen desire of radiologists and other clinicians to hear and learn more about the first results obtained with this new equipment in daily clinical practice. This book will satisfy their needs. Professor Maximilian F. Reiser was among the first to install multidetector CT in his department in Munich and to gain experience with this new radiological tool. He was also able to organise a very successful and well attended international meeting on this hot topic as early as z 2000 in Starnberg, Germany.

Download or read book Medical Image Processing Reconstruction and Restoration written by Jiri Jan and published by CRC Press. This book was released on 2005-11-02 with total page 755 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is essential that differently oriented specialists and students involved in image processing have a firm grasp of the necessary concepts and principles. A single-source reference that can provide this foundation, as well as a thorough explanation of the techniques involved, particularly those found in medical image processing, would be an

Download or read book Radiation Dose from Adult and Pediatric Multidetector Computed Tomography written by D. Tack and published by Springer Science & Business Media. This book was released on 2007-12-31 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book considers in depth all the factors that influence the radiation dose and the risk associated with MDCT in children and adults. Only a small proportion of referring clinicians, radiologists, and technologists are aware of both the radiation risks and their underlying mechanisms. The book proposes detailed guidelines for optimization of the radiation dose when using MDCT. It is written by experts of international standing.

Download or read book Computed Tomography written by Euclid Seeram and published by Saunders. This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiologic technologists play an important role in the care and management of patients undergoing advanced imaging procedures. This new edition provides the up-to-date information and thorough coverage you need to understand the physical principles of computed tomography (CT) and safely produce high-quality images. You'll gain valuable knowledge about the practice of CT scanning, effective communication with other medical personnel, and sectional anatomic images as they relate to CT. Features a chapter devoted to quality control testing of CT scanners (both spiral CT and conventional scan-and-stop), helping you achieve and maintain high quality control standards. Provides the latest information on: advances in volume CT scanning; CT fluoroscopy; multi-slice spiral/helical CT; and multi-slice applications such as 3-D imaging, CT angiography, and virtual reality imaging (endoscopy)--all with excellent coverage of state-of-the-art principles, instrumentation, clinical applications and quality control. Two new chapters cover recent developments and important principles of multislice CT and PET/CT, giving you in-depth coverage of these quickly emerging aspects of CT.

Download or read book Diseases of the Chest Breast Heart and Vessels 2019 2022 written by Juerg Hodler and published by Springer. This book was released on 2019-02-19 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book focuses on diagnostic and interventional imaging of the chest, breast, heart, and vessels. It consists of a remarkable collection of contributions authored by internationally respected experts, featuring the most recent diagnostic developments and technological advances with a highly didactical approach. The chapters are disease-oriented and cover all the relevant imaging modalities, including standard radiography, CT, nuclear medicine with PET, ultrasound and magnetic resonance imaging, as well as imaging-guided interventions. As such, it presents a comprehensive review of current knowledge on imaging of the heart and chest, as well as thoracic interventions and a selection of "hot topics". The book is intended for radiologists, however, it is also of interest to clinicians in oncology, cardiology, and pulmonology.

Download or read book Multislice CT written by Konstantin Nikolaou and published by Springer. This book was released on 2019-08-06 with total page 1116 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fourth edition of this well-received book offers a comprehensive update on recent developments and trends in the clinical and scientific applications of multislice computed tomography. Following an initial section on the most significant current technical aspects and issues, detailed information is provided on a comprehensive range of diagnostic applications. Imaging of the head and neck, the cardiovascular system, the abdomen, and the lungs is covered in depth, describing the application of multislice CT in a variety of tumors and other pathologies. Emerging fields such as pediatric imaging and CT-guided interventions are fully addressed, and emergency CT is also covered. Radiation exposure, dual-energy imaging, contrast enhancement, image postprocessing, CT perfusion imaging, and CT angiography all receive close attention. The new edition has been comprehensively revised and complemented by contributions from highly experienced and well-known authors who offer diverse perspectives, highlighting the possibilities offered by the most modern multidetector CT systems. This book will be particularly useful for general users of CT systems who wish to upgrade and enhance not only their machines but also their knowledge.

Download or read book Medical Imaging Informatics written by Alex A.T. Bui and published by Springer Science & Business Media. This book was released on 2009-12-01 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Medical Imaging Informatics provides an overview of this growing discipline, which stems from an intersection of biomedical informatics, medical imaging, computer science and medicine. Supporting two complementary views, this volume explores the fundamental technologies and algorithms that comprise this field, as well as the application of medical imaging informatics to subsequently improve healthcare research. Clearly written in a four part structure, this introduction follows natural healthcare processes, illustrating the roles of data collection and standardization, context extraction and modeling, and medical decision making tools and applications. Medical Imaging Informatics identifies core concepts within the field, explores research challenges that drive development, and includes current state-of-the-art methods and strategies.

Download or read book CT Scanning written by Karupppasamy Subburaj and published by BoD – Books on Demand. This book was released on 2011-10-03 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its introduction in 1972, X-ray computed tomography (CT) has evolved into an essential diagnostic imaging tool for a continually increasing variety of clinical applications. The goal of this book was not simply to summarize currently available CT imaging techniques but also to provide clinical perspectives, advances in hybrid technologies, new applications other than medicine and an outlook on future developments. Major experts in this growing field contributed to this book, which is geared to radiologists, orthopedic surgeons, engineers, and clinical and basic researchers. We believe that CT scanning is an effective and essential tools in treatment planning, basic understanding of physiology, and and tackling the ever-increasing challenge of diagnosis in our society.