PET (positron emission tomography) scan uses radioactive tracers and detects biochemical activity within the body. It provides quantitative data on physiological processes. The document discusses the basic physics behind PET including positron decay, annihilation, and detection of gamma rays. It describes the detectors and image acquisition system used in PET scans. The document outlines several clinical applications of PET scans including oncology, neurology, and cardiology. It provides examples of PET scan images and findings that demonstrate lesions detected.
This document discusses the basics of PET imaging including positron emission, fluorine-18 production and decay, FDG synthesis, tumor physiology and uptake, detection methods, and scanning techniques. It also covers applications of PET imaging in cardiac imaging like assessing myocardial viability and perfusion, as well as atherosclerotic plaque characterization and inflammation.
PET scanning uses radioactive tracers and positron emission tomography to produce functional images of the body. PET/CT combines PET and CT imaging, allowing for both functional and anatomical data to be collected simultaneously and coregistered into a single image. This provides higher diagnostic accuracy than either PET or CT alone. The most common PET radiotracer is FDG, a glucose analog that is taken up by metabolically active cells and can be used to detect cancer and other diseases. PET/CT has numerous advantages but also some disadvantages related to increased radiation dose and potential motion artifacts.
PET-CT and PET-MR provide functional imaging through PET as well as anatomical imaging through CT or MRI. PET involves radiolabeling molecules like FDG with positron emitters, injecting them into patients, and using coincident detection of annihilation photons to construct 3D images. PET-CT provides accurate localization of functional abnormalities and distinction of normal from pathological tracer uptake. Whole-body PET-MRI is an emerging technique that combines the molecular imaging of PET with the excellent soft tissue contrast of MRI.
This document discusses PET and thyroid scans. PET uses radioactive tracers to provide metabolic and functional imaging, and has better resolution than SPECT but is more expensive. Thyroid scans use radioactive iodine or technetium tracers to evaluate the thyroid gland for abnormalities, nodules, or cancer. Both scans involve injecting or ingesting radioactive tracers and using gamma cameras to detect their accumulation and distribution in the body to assess health and function.
It includes history, components, principle, it's benefits and risk in very concise way and point to point information. Points are in bullet and bold form, so you can easy grab it.
Hybrid imaging refers to the fusion of images from two or more imaging modalities to provide complementary anatomical and functional information. PET/CT was the first widely used hybrid imaging technique, combining the functional imaging of PET with the anatomical details of CT. This allows clinicians to more accurately localize tracer uptake and stage diseases like cancer. More recently, PET/MRI has also emerged as a hybrid technique, offering soft tissue contrast superior to CT while avoiding additional radiation exposure. Both hardware-based scanners that acquire data simultaneously and software-based techniques that co-register images are used to generate hybrid images.
PET imaging provides functional information about metabolic processes in the body. It is used in cardiology to non-invasively evaluate myocardial blood flow, metabolism, and viability. Tracers such as rubidium-82, ammonia-13, fluorodeoxyglucose, and oxygen-15 are injected and imaged to assess perfusion and glucose uptake, identifying ischemic, hibernating, and infarcted tissue. PET MPI has high sensitivity and specificity for CAD detection compared to other tests.
PET CT combines functional imaging using positron emission tomography (PET) with anatomical imaging using computed tomography (CT). PET detects gamma rays emitted by radiotracers administered to the patient to construct 3D images showing metabolic or biochemical processes. CT provides detailed anatomical images for context. The document discusses the principles and components of PET CT scanning, including radiotracer production and synthesis, scanner design using detector rings, coincidence detection, data acquisition and reconstruction to produce diagnostic images.
This document discusses the basics of PET imaging including positron emission, fluorine-18 production and decay, FDG synthesis, tumor physiology and uptake, detection methods, and scanning techniques. It also covers applications of PET imaging in cardiac imaging like assessing myocardial viability and perfusion, as well as atherosclerotic plaque characterization and inflammation.
PET scanning uses radioactive tracers and positron emission tomography to produce functional images of the body. PET/CT combines PET and CT imaging, allowing for both functional and anatomical data to be collected simultaneously and coregistered into a single image. This provides higher diagnostic accuracy than either PET or CT alone. The most common PET radiotracer is FDG, a glucose analog that is taken up by metabolically active cells and can be used to detect cancer and other diseases. PET/CT has numerous advantages but also some disadvantages related to increased radiation dose and potential motion artifacts.
PET-CT and PET-MR provide functional imaging through PET as well as anatomical imaging through CT or MRI. PET involves radiolabeling molecules like FDG with positron emitters, injecting them into patients, and using coincident detection of annihilation photons to construct 3D images. PET-CT provides accurate localization of functional abnormalities and distinction of normal from pathological tracer uptake. Whole-body PET-MRI is an emerging technique that combines the molecular imaging of PET with the excellent soft tissue contrast of MRI.
This document discusses PET and thyroid scans. PET uses radioactive tracers to provide metabolic and functional imaging, and has better resolution than SPECT but is more expensive. Thyroid scans use radioactive iodine or technetium tracers to evaluate the thyroid gland for abnormalities, nodules, or cancer. Both scans involve injecting or ingesting radioactive tracers and using gamma cameras to detect their accumulation and distribution in the body to assess health and function.
It includes history, components, principle, it's benefits and risk in very concise way and point to point information. Points are in bullet and bold form, so you can easy grab it.
Hybrid imaging refers to the fusion of images from two or more imaging modalities to provide complementary anatomical and functional information. PET/CT was the first widely used hybrid imaging technique, combining the functional imaging of PET with the anatomical details of CT. This allows clinicians to more accurately localize tracer uptake and stage diseases like cancer. More recently, PET/MRI has also emerged as a hybrid technique, offering soft tissue contrast superior to CT while avoiding additional radiation exposure. Both hardware-based scanners that acquire data simultaneously and software-based techniques that co-register images are used to generate hybrid images.
PET imaging provides functional information about metabolic processes in the body. It is used in cardiology to non-invasively evaluate myocardial blood flow, metabolism, and viability. Tracers such as rubidium-82, ammonia-13, fluorodeoxyglucose, and oxygen-15 are injected and imaged to assess perfusion and glucose uptake, identifying ischemic, hibernating, and infarcted tissue. PET MPI has high sensitivity and specificity for CAD detection compared to other tests.
PET CT combines functional imaging using positron emission tomography (PET) with anatomical imaging using computed tomography (CT). PET detects gamma rays emitted by radiotracers administered to the patient to construct 3D images showing metabolic or biochemical processes. CT provides detailed anatomical images for context. The document discusses the principles and components of PET CT scanning, including radiotracer production and synthesis, scanner design using detector rings, coincidence detection, data acquisition and reconstruction to produce diagnostic images.
This document discusses fusion imaging, which combines images from different modalities to create a hybrid image. It describes fusion imaging techniques like PET-CT and SPECT-CT that merge functional imaging data with anatomical images. The primary advantage of fusion imaging is that it allows correlation of findings from two concurrent imaging modalities, providing both anatomical and functional/metabolic information in a single exam. Specifically, PET-CT fusion improves diagnostic accuracy and lesion localization by overcoming the limitations of each individual modality. In conclusion, combined PET-CT exams are more effective than PET alone for localizing lesions and differentiating normal variants from tumors.
Positron emission tomography and its application in veterinary fieldIrawati Sarode
Positron emission tomography (PET) is a nuclear imaging technique that produces 3D images of functional processes in the body by detecting radiation emitted from radiotracers administered to the patient. PET provides valuable information about metabolic activity at the cellular level and is useful for cancer diagnosis, staging, and monitoring treatment response. PET has various applications in veterinary medicine, including oncology, neurology, cardiology, and musculoskeletal imaging to study diseases in large and small animals.
This document discusses brain PET imaging for tumors, including normal brain uptake patterns, radiotracers like FDG and amino acids, factors affecting glioma uptake, and clinical indications for PET/CT and PET/MR imaging in gliomas. It provides details on the various radiotracers, their uses, and examples of images. Key points are that PET is useful for differentiating tumor recurrence from radiation necrosis, tumor grading, delineating edges for surgery/radiation, and provides prognostic information. Amino acids are best for recurrence differentiation while FDG is more advantageous for grading.
Physics of Nuclear Medicine, SPECT and PET.pptHassan Chattha
This document provides an overview of nuclear medicine imaging techniques including SPECT and PET. It discusses the basics of gamma cameras and how they form images using collimators. SPECT imaging is described including data acquisition in projections, reconstruction using filtered back projection, and corrections for attenuation and scatter. PET imaging concepts such as coincidence detection, time-of-flight, and the need for corrections for randoms, scatter, and attenuation are covered. The document compares the relative sensitivities, resolutions, and data corrections between SPECT and PET.
Positron Emission Tomography (PET) is a nuclear imaging technique that detects pairs of gamma rays emitted by a positron-emitting radiotracer to produce three-dimensional images of functional processes in the body. PET scans are often combined with computed tomography (CT) to provide both functional and anatomic information. PET/CT has advantages over PET alone in improving diagnostic accuracy, decreasing scan time, and better localizing areas of abnormal activity. Limitations include increased radiation exposure compared to PET and potential motion artifacts from combining the two modalities. Emerging hybrid imaging technologies include PET/MRI which provides improved soft tissue contrast compared to CT but also faces challenges from the magnetic fields interfering with standard PET detector technology.
Positron emission tomography (PET) is an imaging technique that uses radiolabeled tracers to produce images showing their distribution in the body. During a PET scan, a tracer containing a radioactive isotope is injected and decays, emitting positrons. The positrons interact with electrons, producing pairs of gamma rays detected by the PET scanner to reconstruct images. PET scans are used to study brain function, detect and characterize cancers, and examine heart disease. Advantages include showing tissue function, but disadvantages include expense and limited availability.
What is pet scan, it's principle, components of pet, pet working , cases of pet , pet clinical applications PET/CT, Disadvantages and accuracy.#PETSCAN
This pdf is about the Positron Emission Tomography (PET) technique.
For more details visit on YouTube; @SELF-EXPLANATORY;
PET; https://youtu.be/rlwGbFGS6wg
Thanks...!
Radioisotope techniques involve the spontaneous disintegration of atomic nuclei through processes like alpha, beta, and gamma decay. Radioactivity is measured in units like curie and becquerel. There are different types of radioactive decay including alpha, beta, gamma, positron, electron capture, and isomeric transition. Radiopharmaceuticals are chemical substances containing radioactive atoms used as tracers in nuclear medicine for diagnosis and therapy. The most commonly used radiopharmaceutical is technetium-99m, which is used in over 80% of nuclear medicine procedures. Other radiopharmaceuticals employ radioisotopes of iodine, indium, fluorine and other elements.
Calcitonin is a hormone that is produced in humans by the parafollicular cells (commonly known as C-cells) of the Thyroid Gland. Calcitonin is involved in helping to regulate levels of calcium and phosphate in the blood, opposing the action of Parathyroid Hormone. This means that it acts to reduce calcium levels in the blood. However, the importance of this role in humans is unclear, as patients who have very low or very high levels of calcitonin show no adverse effects.
PET scans use small amounts of radioactive tracers injected into the body to produce images showing how organs and tissues are functioning. A PET scan works by detecting gamma rays emitted by the tracers, allowing visualization of processes like blood flow, metabolic activity, and biochemical processes. PET scans are used to diagnose and manage conditions like cancer, heart disease, and neurological disorders.
Positron emission tomography (PET) is a nuclear medicine imaging technique that produces 3D images of functional processes in the body. It works by detecting pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (radiotracer) introduced into the body on a biologically active molecule. A PET scan can provide metabolic information about normal and abnormal tissues that can help detect and diagnose disease. Common clinical uses include evaluating cancer, heart disease, brain disorders, and more. Limitations include cost and the need for on-site facilities to produce short-lived radiotracers.
This document discusses fusion imaging, which combines images from different modalities to create a hybrid image. It describes fusion imaging techniques like PET-CT and SPECT-CT that merge functional imaging data with anatomical images. The primary advantage of fusion imaging is that it allows correlation of findings from two concurrent imaging modalities, providing both anatomical and functional/metabolic information in a single exam. Specifically, PET-CT fusion improves diagnostic accuracy and lesion localization by overcoming the limitations of each individual modality. In conclusion, combined PET-CT exams are more effective than PET alone for localizing lesions and differentiating normal variants from tumors.
Positron emission tomography and its application in veterinary fieldIrawati Sarode
Positron emission tomography (PET) is a nuclear imaging technique that produces 3D images of functional processes in the body by detecting radiation emitted from radiotracers administered to the patient. PET provides valuable information about metabolic activity at the cellular level and is useful for cancer diagnosis, staging, and monitoring treatment response. PET has various applications in veterinary medicine, including oncology, neurology, cardiology, and musculoskeletal imaging to study diseases in large and small animals.
This document discusses brain PET imaging for tumors, including normal brain uptake patterns, radiotracers like FDG and amino acids, factors affecting glioma uptake, and clinical indications for PET/CT and PET/MR imaging in gliomas. It provides details on the various radiotracers, their uses, and examples of images. Key points are that PET is useful for differentiating tumor recurrence from radiation necrosis, tumor grading, delineating edges for surgery/radiation, and provides prognostic information. Amino acids are best for recurrence differentiation while FDG is more advantageous for grading.
Physics of Nuclear Medicine, SPECT and PET.pptHassan Chattha
This document provides an overview of nuclear medicine imaging techniques including SPECT and PET. It discusses the basics of gamma cameras and how they form images using collimators. SPECT imaging is described including data acquisition in projections, reconstruction using filtered back projection, and corrections for attenuation and scatter. PET imaging concepts such as coincidence detection, time-of-flight, and the need for corrections for randoms, scatter, and attenuation are covered. The document compares the relative sensitivities, resolutions, and data corrections between SPECT and PET.
Positron Emission Tomography (PET) is a nuclear imaging technique that detects pairs of gamma rays emitted by a positron-emitting radiotracer to produce three-dimensional images of functional processes in the body. PET scans are often combined with computed tomography (CT) to provide both functional and anatomic information. PET/CT has advantages over PET alone in improving diagnostic accuracy, decreasing scan time, and better localizing areas of abnormal activity. Limitations include increased radiation exposure compared to PET and potential motion artifacts from combining the two modalities. Emerging hybrid imaging technologies include PET/MRI which provides improved soft tissue contrast compared to CT but also faces challenges from the magnetic fields interfering with standard PET detector technology.
Positron emission tomography (PET) is an imaging technique that uses radiolabeled tracers to produce images showing their distribution in the body. During a PET scan, a tracer containing a radioactive isotope is injected and decays, emitting positrons. The positrons interact with electrons, producing pairs of gamma rays detected by the PET scanner to reconstruct images. PET scans are used to study brain function, detect and characterize cancers, and examine heart disease. Advantages include showing tissue function, but disadvantages include expense and limited availability.
What is pet scan, it's principle, components of pet, pet working , cases of pet , pet clinical applications PET/CT, Disadvantages and accuracy.#PETSCAN
This pdf is about the Positron Emission Tomography (PET) technique.
For more details visit on YouTube; @SELF-EXPLANATORY;
PET; https://youtu.be/rlwGbFGS6wg
Thanks...!
Radioisotope techniques involve the spontaneous disintegration of atomic nuclei through processes like alpha, beta, and gamma decay. Radioactivity is measured in units like curie and becquerel. There are different types of radioactive decay including alpha, beta, gamma, positron, electron capture, and isomeric transition. Radiopharmaceuticals are chemical substances containing radioactive atoms used as tracers in nuclear medicine for diagnosis and therapy. The most commonly used radiopharmaceutical is technetium-99m, which is used in over 80% of nuclear medicine procedures. Other radiopharmaceuticals employ radioisotopes of iodine, indium, fluorine and other elements.
Calcitonin is a hormone that is produced in humans by the parafollicular cells (commonly known as C-cells) of the Thyroid Gland. Calcitonin is involved in helping to regulate levels of calcium and phosphate in the blood, opposing the action of Parathyroid Hormone. This means that it acts to reduce calcium levels in the blood. However, the importance of this role in humans is unclear, as patients who have very low or very high levels of calcitonin show no adverse effects.
PET scans use small amounts of radioactive tracers injected into the body to produce images showing how organs and tissues are functioning. A PET scan works by detecting gamma rays emitted by the tracers, allowing visualization of processes like blood flow, metabolic activity, and biochemical processes. PET scans are used to diagnose and manage conditions like cancer, heart disease, and neurological disorders.
Positron emission tomography (PET) is a nuclear medicine imaging technique that produces 3D images of functional processes in the body. It works by detecting pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (radiotracer) introduced into the body on a biologically active molecule. A PET scan can provide metabolic information about normal and abnormal tissues that can help detect and diagnose disease. Common clinical uses include evaluating cancer, heart disease, brain disorders, and more. Limitations include cost and the need for on-site facilities to produce short-lived radiotracers.
Similar to positronemissiontomographypetscananditsapplications_210225164330.pptx (20)
- Cystic bone lesions include solitary bone cysts, aneurysmal bone cysts, intraosseous ganglion cysts, and epidermoid cysts. Unicameral bone cysts typically occur in the humerus or femur of children and adolescents and may heal spontaneously at skeletal maturity. Aneurysmal bone cysts contain blood-filled cavities and commonly involve the proximal humerus, distal femur, and proximal tibia. Intraosseous ganglion cysts have similarities to soft tissue ganglions and contain mucoid fluid. Epidermoid bone cysts are rare and contain keratinous material. Surgical curettage is often used to treat symptomatic cystic bone
The document provides an orientation for observers at Children's Hospital and Health System. It outlines the purpose of the observer program, which is to allow interested individuals to explore healthcare careers by shadowing hospital staff. It then details the organization's mission to provide high-quality pediatric care, education, research, and community advocacy. The document reviews rules of conduct, safety procedures during emergencies, infection control protocols, security information, and concludes by thanking the observer for completing the orientation.
This document provides information about several English tenses:
1. It explains the simple present tense, used to describe facts, habitual actions, and future schedules. Examples are given of affirmative, negative, and interrogative sentences.
2. The simple past tense is described as used for completed past actions and repeated past actions. Example sentences show its formation.
3. Details are given on the present continuous, past continuous, present perfect, and past perfect tenses. For each, examples demonstrate how to form affirmative, negative, and interrogative sentences in that tense.
Orthopaedic surgery patients are at very high risk for developing dangerous blood clots called deep vein thromboses (DVTs). Without preventative measures, the risk of DVTs in these patients ranges from 40-60%. However, using prophylaxis like blood thinners, compression stockings, or pneumatic compression devices can reduce the risk to 1.3-10%. Guidelines recommend low molecular weight heparins, low-dose unfractionated heparins, or newer oral anticoagulants to prevent DVTs in orthopaedic patients undergoing hip or knee replacement or hip fracture surgery. Mechanical methods alone are not sufficient prophylaxis due to non-compliance issues.
The hip joint is a ball and socket joint formed between the femur and acetabulum. It allows for flexion, extension, abduction, adduction, and rotation. The joint is stabilized by ligaments like the iliofemoral and labrum. Seventeen muscles control hip movement and are divided into four groups - gluteals, lateral rotators, adductors, and iliopsoas. The gluteals externally rotate and extend the hip while the iliopsoas flex and internally rotate.
The document provides an overview of equinus deformity and its surgical correction in patients with cerebral palsy. It discusses the anatomy and causes of equinus deformity. Several surgical techniques for correcting the deformity are described in detail, including open lengthening of the Achilles tendon using the White modification or Z-plasty techniques, as well as percutaneous and gastrocnemius-soleus lengthening procedures. Postoperative management involves casting and bracing to maintain correction while allowing for muscle growth. Surgical correction aims to improve ambulation and care but must be tailored to each patient's needs and deformity severity.
This document discusses surgical techniques for correcting foot deformities in cerebral palsy patients, including:
1) Lengthening the posterior tibial tendon through open Z-plasty or musculotendinous recession to treat equinovarus deformity.
2) Split tendon transfers like the Kling-Kaufer-Hensinger posterior tibial transfer or Hoffer anterior tibial transfer to balance muscle forces.
3) Osteotomy of the calcaneus using Dwyer's technique for fixed varus deformities, combined with soft tissue procedures.
This document provides strategies and guidelines for answering structure questions on the TOEFL exam. It discusses 9 key skills for these types of questions: subjects and verbs, objects of prepositions, present and past participles, coordinate connectors, adverb clause connectors, noun clause connectors, noun clause connector/subjects, and adjective clause connectors. For each skill, it provides examples of sentences with missing words and explains the underlying grammar rules to apply when considering which answer choice correctly completes the sentence. The overall document aims to help test-takers understand and apply English grammar concepts to correctly answer structure questions on the TOEFL exam.
Gradable adjectives can be compared using comparative and superlative forms to show degrees of a quality. The comparative form typically adds "-er" and uses "than" to compare two items or people, showing superiority or inferiority. The superlative uses "-est" and "the" to denote the highest degree of a quality compared to three or more items. Examples are given for common adjectives like fast, clean, and big.
This document discusses medical ethics and its principles. It begins by defining ethics and medical ethics, noting that medical ethics deals with moral issues in medical practice. It then outlines four basic principles of medical ethics: respect for patient autonomy, non-maleficence, beneficence, and justice. The document also discusses public health ethics, research ethics, and some top ethical issues in healthcare such as balancing care quality and access. It emphasizes that quality care is built upon ethical standards and principles.
SI dislocations and fractures can be incomplete or complete, with complete injuries rupturing the posterior ligaments and causing vertical and rotational instability. Crescent fractures involve an iliac wing fracture entering the SI joint. Injuries usually result from lateral compression and may be associated with open wounds or bowel involvement. Accurate reduction and stable fixation of the SI joint determines prognosis. Iliac wing fractures have a high risk of associated injuries like bowel entrapment.
The document summarizes the treatment options for osteoarthritis of the knee. It discusses conservative treatments like physiotherapy, analgesics, and lifestyle changes for early stage osteoarthritis. For intermediate stages, options like joint debridement, autologous chondrocyte grafting, and realignment osteotomies are covered. Late stage treatments discussed include arthroplasty procedures like knee replacement as well as arthrodesis. Surgical techniques for various realignment osteotomies and knee replacement are explained in detail.
This document summarizes common nerve injuries in the upper and lower extremities. In the upper limb, it describes injuries to the axillary, radial, median, and ulnar nerves, including their sensory and motor functions, common causes of injury, and clinical manifestations. For the lower limb, it discusses femoral, sciatic, and common peroneal nerve injuries, noting signs and symptoms such as sensory loss, muscle weakness or deformities like drop foot. The document provides an overview of peripheral nerve injuries and their presentations to help clinicians properly diagnose different conditions.
This document provides an overview of osteoarthritis of the knee. It defines osteoarthritis as a non-inflammatory degenerative joint condition. It describes the pathology and changes that occur in the articular cartilage, bone, synovial membrane, capsule, ligaments and muscles. Risk factors, clinical presentation, diagnostic tests including x-rays and MRI, and grading scales are outlined. Both non-surgical and surgical treatment options are discussed including exercises, braces, medications, injections, osteotomies and knee replacements.
Locked plating involves a screw and plate construct where the screw engages coupling holes in the plate, securing a fixed angle. It provides increased rigidity over non-locking plates through a locked interface between the screw head and plate. This monobloc effect allows all screws to bear weight simultaneously, reducing failure risks compared to sequential loading in non-locking plates. Correct usage of locked plating requires understanding its mechanics, indications, and techniques to achieve anatomic reduction and stability.
This document provides an overview of ankle fracture patterns, classifications, radiographic evaluation, treatment approaches, and postoperative management. Key points include that ankle fractures can be classified anatomically or using the Lauge-Hansen system, radiographs include stress views to assess ligament injuries, treatment depends on fracture displacement and stability, and goals are anatomic reduction and fixation to restore the ankle mortise. Complications include wound issues, infection, and post-traumatic arthritis.
This document provides an overview of classifications and management approaches for fractures and dislocations of the thoracic and lumbar spine. It discusses several classification systems, including the Denis system which divides the spine into three columns, and the TLICS system which scores injuries based on morphology, posterior ligament integrity and neurologic status to determine surgical vs non-surgical management. For most thoracolumbar injuries without neurologic deficit, non-surgical treatment is appropriate. Surgical intervention may improve mobilization and function for unstable fractures or injuries involving neurologic compression. The goals of management are maximizing neurologic recovery while stabilizing the spine to facilitate early rehabilitation.
1. The extensor mechanism of the fingers consists of the central slip and lateral bands which insert at various joints to extend the fingers.
2. Injuries can occur in different zones from the DIP to the forearm. Zone I injuries occur at the DIP joint while zone II injuries involve the lateral bands.
3. Boutonniere deformities result from zone III injuries where the central slip is disrupted. Management depends on the chronicity and severity of the deformity.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
1. Positron emission tomography PET
Scan and its Applications
Presenter: - Yashawant Yadav
BSc. MIT 3RD year
NAMS, Bir Hospital
1
2/25/2021
2. Outlines
• Introduction of PET Scan
• Basic physic behind PET
• Detectors and image acquisition system
• Advancement
• Application of PET
• References
3. Introduction
• Positron Emission Tomography (PET) is a method for measuring biochemical and
physiological processes in vivo in a quantitative way by using
radiopharmaceuticals labelled with positron emitting radionuclides such as 11C,
13N, 15O and 18F.
• PET employs mainly short-lived positron emitting radiopharmaceuticals.
• The most widely used radionuclides are: 11C (t1/2 = 20 min), 13N (t1/2 = 10 min),
15O (t1/2 = 2 min) and 18F (t1/2 = 110 min).
• These radionuclides are produced in a (baby) cyclotron and are then used to label
compounds of biological interest.
4. • In cancerous cells metabolic changes occur much before the cells undergo changes
like dysplasia, metaplasia or anaplasia.
• This is finally followed by structural changes at a later stage.
• PET scan detects the disease at the metabolic level while anatomical imaging
techniques like CT or MRI detect the disease at the structural level.
Why PET ????
5. • Positron
• Gamma ray
• Proton
• Light photons
• Decay Emission Production Detection
What we detect in PET scan ??
6. • Number of proton(z)= atomic number
• Total number of nucleons(A)= mass number
proton+ neutron
Basic atomic physic
12. • The method is based on identifying the increased glycolytic activity in malignant
cells,
• Increase in membrane glucose transporters as well as to an increase in some of
the principal enzymes, such as hexokinase.(at site of tumor )
• Glucose transporter proteins known as GLUT -1 transporters and subsequently
phosphorylated by hexokinase.
Radiopharmaceuticals uptake in PET
13. Decay possibilities for neutron deficient Radionuclides
There is 2 possibilities: -
1. Positron decay
2. Electron capture
For positron decay energy should be at least 1022KeV or more and number of
proton should be lesser (lower atomic number atoms )
For electron capture energy needed lower than 1022KeV and number of protons
should be higher (higher atomic number atoms )
15. Why photons apart at 1800 ??
• With positron decay two conservation laws have to be obeyed:
i) conservation of energy and
ii) conservation of momentum. (m*v)
Conservation of energy is followed by conversion of mass in to gamma ray photons
and momentum is conserved by produced gamma photons moving in opposite
direction to each other and cancel momentum of each other.
The three-quanta annihilation only happens if the formed positronium is in its triplet
state, which is rare, with a half-life of 7 µs.
In the singlet state the positronium decays with a lifetime of 4-8 ns.
16. • Proton range (before annihilation)
• Non collinearity (after annihilation)
Phenomenon
The positron range error is dependent on the energy of the emitted positrons. Non colinearity is
independent of radionuclide, and the error is determined by the separation of the detectors. The deviation
from non colinearity is highly exaggerated in the figure; the average angular deviation from 180° is about
0.25°.
17. Contd..
• The anti-parallel photons are recorded, and the
virtual line connecting the two points is called the
line of response (LoR)
• In a conventional PET system, positron annihilation
is assumed to be localized somewhere along the
LoR without information regarding the exact
interaction point.
18.
19. Contd…
• Coincidence measurements and
ideally measurement of the time
difference, called Time Of Flight
(TOF) measurement.
• It has Depth function
• A major trend in PET
instrumentation is the development
of time-of-flight positron emission
tomography (ToF-PET).
20. Contd…
• ToF-PET leads to better localization of the annihilation event and thus results in
overall improvement in the signal-to-noise ratio (SNR) of the reconstructed image.
• The technique by which the image is reconstructed without using ToF information
is called conventional PET and that incorporating ToF information is abbreviated
as ToF-PET
21.
22. Confounding's needed to be estimated
Patient related confounding’s are attenuation , scattering and random coincidence,
patients motion could be the main confounding Factor
23. Detector of PET system
The scintillator characteristics:-
a) stopping power,
b) light output (yield and wave length) and
c) decay time
• Cesium fluoride (CsF) and barium fluoride (BaF2) detectors were used in the first-
generation TOF-PET.
• CsF needs careful packaging as it is highly hygroscopic. In addition, limited
sensitivity (stopping power), low light output.
24. Contd..
• During the 1970s and early 1980s, bismuth germinate (BGO) was used as the
standard scintillator for PET detectors because of its high detection efficiency and
acceptable light output in commercial PET systems.
1.Newer scintillators such as lutetium orthosilicate (Lu2SiO2) (LSO)
(traditional LSO:Ce scintillato0rs) (In recent years, LSO co-doped with Ca)
(LYSO:Ce) (lutetium yttrium oxyorthosilicate)
2.GSO (gadolinium oxyorthosilicate), LaBr3:Ce (cerium-doped lanthanum
bromide), Ce:GAGG (cerium-doped gadolinium aluminum gallium garnet)
(Gd3Al2Ga3O12:Ce or GAGG:Ce).
25. Contd…
• Detectors based on CZT (cadmium zinc telluride) do not use scintillators because
they directly convert ionizing radiation to charge production, providing higher
energy and spatial resolutions than scintillator-based PET detectors.
• CdTe (cadmium telluride) is another stable crystalline compound
• In terms of detector design, recent PET scanners do not have septa and therefore
images are acquired only in three-dimensional (3D) mode.
26. • There are generally four types of sensor technologies employed:
• photomultiplier tubes (PMTs),
• Avalanche photodiodes (APDs),
• silicon photomultipliers (SiPMs), and
• cadmium zinc telluride (CZT) detectors.
• Spatial resolution of the conventional human PET system was usually 4.5–6 mm
due to the limitation of the sensing technology
Contd..
27.
28. • New-generation PET detectors have silicon photomultipliers (SiPM) instead of
photomultipliers tube (PMT).
• The main benefits of SiPM comprise compact and rugged, high gain , good
intrinsic timing resolution, and higher value of photon detection efficiency than
PMTs.
• In addition, the SiPM detector is insensitive to the electromagnetic interference
and this is the most important feature of the PET/magnetic resonance (MR)
system.
Contd…
33. Clinical application
• The clinical impact and use of PET remained restricted until availability of
Medical/Baby cyclotrons,
• In the late 1990s 18F- fluorodeoxyglucose (FDG) as the radiopharmaceutical
began to be used widely in evaluation of oncology patients.
• The clinical use of PET received a major boost in 1998, when PET scanning was
approved by health care agencies in USA.
• The basis of PET imaging is the detection of altered metabolism in biological
tissues.
34. Contd…
• Tumor Proliferation
Carbon-11 thymidine and F-18 Fluorothymidine (FLT) an analog of thymidine are
markers of cellular proliferation. Analog to FDG (to predict tumor grade in lung
cancers, evaluate brain tumors)
11C methionine and amino acid, has shown great promise in evaluating brain
tumors and other cancers too.
11C-choline and 11C-acetate have been used in prostate cancer to evaluate the
primary and metastatic disease
35. Contd…
• Myocardial Perfusion Imaging
• Rubidium-82 is a potassium analog agent to assess myocardial perfusion in the
same way as Thallium 201 or Technetium -99 labelled compounds.
• Nitrogen-13 labelled ammonia is another PET tracer used for myocardial
perfusion studies.
• Skeletal Imaging
• F-18 Sodium fluoride has shown great promise as a bone scan agent, comparable
to or even superior to Technetium -99 labelled MDP.
•Brain Imaging
Listed above in table
36. Contd…
The goals of oncologic imaging remain lesion detection, lesion characterization,
staging of malignant lesions and assessment of the therapeutic response.
• Brain
• Head and Neck
• Lungs
• Esophageal Cancer
• Colorectal Carcinoma
• Lymphoma
• Carcinoma Breast
• Cervical and Ovarian Carcinoma
• Renal, Prostate and Bladder Cancers
• Testicular Cancers
• Melanoma
• Musculoskeletal Tumors
• Dementias
• Epilepsy
• Movement Disorders
• Stroke and Cerebrovascular Disease (CVD)
• Myocardial Viability
• Coronary Artery Evaluation
• Coronary Perfusion Reserve
37.
38. • Anterior projection images from a PET
scan of a patient undergoing staging of
lymphoma. (a) The initial study was
performed after the patient had eaten a
candy bar 30 minutes prior to FDG
injection. Note the extensive myocardial
and muscle uptake due to high insulin
levels. Diminished activity is seen in the
brain and in tumor sites in the neck and
chest (arrows).
• (b) A repeat study after the patient
complied with routine fasting preparation
shows more normal biodistribution of
tracer and better visualization of tumor
deposits
FINDINGS
39. • A patient being evaluated for metastatic colon cancer. (a) An anterior
projection PET image shows known hepatic metastases, as well as an
indeterminate focus in the left face (arrow). (b) Trans axial PET through the
face shows a distinct hypermetabolic focus (arrow). The
corresponding (c) CT and (d) fusion images show this focus to be a
periodontal abscess in the maxillary alveolar ridge
40. • A patient being restaged for colon cancer. (a) PET image shows focal
uptake consistent with recurrence (dashed circle) but does not allow
localization. (b) CT and (c) fusion images show intraabdominal
recurrence (arrow), as well as lesions involving the psoas and iliacus
muscles (arrowheads). Lesser activity elsewhere is physiologic bowel
uptake.
43. • In any PET/CT study there are three discrete image sets that require display. These
are the stand-alone PET data, the CT and the fused PET/CT images.
Contd….
45. • PET–CT imaging is primarily used in oncology, it has also been used to identify brown fat.
• Murine model of disease (pre clinical PET imaging)
• Primary tumor , nodal and distant metastases. ‘(TNM)
• Staging
46.
47.
48. What about bone Mets in MRI PET SCAN ???
• Zero echo time (ZTE) MR imaging provides enhanced bone contrast in MR
imaging and may obviate concomitant CT and its attendant ionizing radiation.
• (MR-based pseudo-CT image conversion.)
• ZTE differs from UTE in the timing of read-out gradients relative to the
excitation radiofrequency (RF) pulse and its acquisition of a single echo time data
set.
• Signal is acquired immediately after application of the RF pulse (echo time = 8
msec). Furthermore, ZTE uses radial k-space filling strategies,
55. • How positron emitter / neutron deficient nucleoid are made?
• What is momentum and how is it conservation?
• What is proton decay and electron capture ?
• Types of detector with example??
Questions