The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
1. Magnetic resonance angiography (MRA) is a non-invasive imaging technique that uses magnetic resonance imaging to visualize blood vessels and evaluate vascular anatomy and blood flow without using ionizing radiation or iodinated contrast material.
2. There are different MRA techniques including time-of-flight MRA, phase contrast MRA, and contrast-enhanced MRA. Time-of-flight MRA relies on differences in flowing and stationary blood signal while phase contrast MRA assesses velocity and direction of flow. Contrast-enhanced MRA uses gadolinium contrast to improve vessel depiction.
3. MRA has various clinical applications for evaluating carotid and intracranial arterial stenosis, aneurysms,
This document provides an overview of diffusion weighted imaging (DWI) and its clinical applications. It defines diffusion and how DWI is acquired using Stejskal-Tanner pulsed gradient spin echo sequences. Key terms like b-value and apparent diffusion coefficient are explained. Clinical uses of DWI include detecting acute strokes and differentiating lesions. Body DWI using DWIBS is also discussed. Diffusion tensor imaging is introduced as a technique for visualizing white matter tract orientation using tractography maps.
Ultrasound artifacts can take various forms including structures that are not actually present, objects that are missing from the image, and structures that are misregistered. Common artifacts include reverberation artifacts seen at skin-transducer interfaces from multiple echoes, ring-down artifacts appearing as lines behind gas collections, and mirror image artifacts duplicating structures. Other artifacts relate to beam characteristics like beam width artifacts where off-axis echoes are misplaced, and side lobes artifacts where side lobe echoes are incorrectly registered. Attenuation errors can cause shadowing or increased through-transmission, while velocity errors result in speed displacement artifacts from variations in sound speed in different tissues.
This document describes the procedures for sialography and dacrocystography. Sialography involves cannulating the ducts of the parotid and submandibular salivary glands and injecting contrast medium to visualize the glands and ducts under fluoroscopy. Dacrocystography involves cannulating the lacrimal puncta and injecting contrast into the nasolacrimal duct system to identify any obstructions. Both procedures provide anatomical imaging of the relevant duct systems to evaluate conditions like stones, strictures, masses or trauma. The document outlines the anatomy, indications, contraindications, technique and expected imaging findings for each procedure.
This document discusses various MRI sequences. It describes spin echo sequences, inversion recovery sequences, gradient echo sequences, and echo planar imaging. Free induction decay is discussed as a short-lived signal appearing after a 90 degree RF pulse that does not contribute to image formation. Parameters, modifications, and uses of different sequences are outlined.
This document defines and classifies different types of artifacts that may appear on CT images. It discusses 11 categories of artifacts: physics-based artifacts (e.g. beam hardening), patient-based artifacts (e.g. metallic artifacts), and scan-based artifacts (e.g. ring artifacts). For each type of artifact, the document describes the cause, appearance on images, and potential solutions to reduce or correct the artifact. The artifacts discussed include beam hardening, metallic streaks, photon starvation, partial volume effects, ring artifacts, cone beam artifacts, tube arcing, step artifacts, motion artifacts, out-of-field artifacts, and aliasing artifacts. The document provides a comprehensive overview of common CT imaging
MRI artifacts can occur due to hardware issues, software problems, physiological phenomena or physical limitations of the MRI device. Common artifacts include chemical shift artifacts seen at fat-water interfaces, aliasing artifacts due to an undersized field of view, black boundary artifacts at tissue borders, and motion artifacts from patient movement. Understanding the sources and appearances of artifacts is important for technicians to maintain image quality and avoid confusing artifacts with pathology.
1. Magnetic resonance angiography (MRA) is a non-invasive imaging technique that uses magnetic resonance imaging to visualize blood vessels and evaluate vascular anatomy and blood flow without using ionizing radiation or iodinated contrast material.
2. There are different MRA techniques including time-of-flight MRA, phase contrast MRA, and contrast-enhanced MRA. Time-of-flight MRA relies on differences in flowing and stationary blood signal while phase contrast MRA assesses velocity and direction of flow. Contrast-enhanced MRA uses gadolinium contrast to improve vessel depiction.
3. MRA has various clinical applications for evaluating carotid and intracranial arterial stenosis, aneurysms,
This document provides an overview of diffusion weighted imaging (DWI) and its clinical applications. It defines diffusion and how DWI is acquired using Stejskal-Tanner pulsed gradient spin echo sequences. Key terms like b-value and apparent diffusion coefficient are explained. Clinical uses of DWI include detecting acute strokes and differentiating lesions. Body DWI using DWIBS is also discussed. Diffusion tensor imaging is introduced as a technique for visualizing white matter tract orientation using tractography maps.
Ultrasound artifacts can take various forms including structures that are not actually present, objects that are missing from the image, and structures that are misregistered. Common artifacts include reverberation artifacts seen at skin-transducer interfaces from multiple echoes, ring-down artifacts appearing as lines behind gas collections, and mirror image artifacts duplicating structures. Other artifacts relate to beam characteristics like beam width artifacts where off-axis echoes are misplaced, and side lobes artifacts where side lobe echoes are incorrectly registered. Attenuation errors can cause shadowing or increased through-transmission, while velocity errors result in speed displacement artifacts from variations in sound speed in different tissues.
This document describes the procedures for sialography and dacrocystography. Sialography involves cannulating the ducts of the parotid and submandibular salivary glands and injecting contrast medium to visualize the glands and ducts under fluoroscopy. Dacrocystography involves cannulating the lacrimal puncta and injecting contrast into the nasolacrimal duct system to identify any obstructions. Both procedures provide anatomical imaging of the relevant duct systems to evaluate conditions like stones, strictures, masses or trauma. The document outlines the anatomy, indications, contraindications, technique and expected imaging findings for each procedure.
This document discusses various MRI sequences. It describes spin echo sequences, inversion recovery sequences, gradient echo sequences, and echo planar imaging. Free induction decay is discussed as a short-lived signal appearing after a 90 degree RF pulse that does not contribute to image formation. Parameters, modifications, and uses of different sequences are outlined.
This document defines and classifies different types of artifacts that may appear on CT images. It discusses 11 categories of artifacts: physics-based artifacts (e.g. beam hardening), patient-based artifacts (e.g. metallic artifacts), and scan-based artifacts (e.g. ring artifacts). For each type of artifact, the document describes the cause, appearance on images, and potential solutions to reduce or correct the artifact. The artifacts discussed include beam hardening, metallic streaks, photon starvation, partial volume effects, ring artifacts, cone beam artifacts, tube arcing, step artifacts, motion artifacts, out-of-field artifacts, and aliasing artifacts. The document provides a comprehensive overview of common CT imaging
MRI artifacts can occur due to hardware issues, software problems, physiological phenomena or physical limitations of the MRI device. Common artifacts include chemical shift artifacts seen at fat-water interfaces, aliasing artifacts due to an undersized field of view, black boundary artifacts at tissue borders, and motion artifacts from patient movement. Understanding the sources and appearances of artifacts is important for technicians to maintain image quality and avoid confusing artifacts with pathology.
Sialography is an x-ray examination of the salivary glands that involves injecting contrast media into the ducts to evaluate any abnormalities. It can detect issues like stones, lesions, or masses that may be obstructing the ducts and causing pain or inflammation. There are three major pairs of salivary glands - parotid, submandibular, and sublingual - which produce saliva. Sialography can be used to evaluate masses, stones, pain, functional disorders, and suspected obstructions or strictures of the salivary glands. The procedure involves injecting contrast media under fluoroscopy and taking x-ray images to view the flow of saliva and identify any ob
This document discusses grids used for scatter control in radiography. It begins with an introduction on grids, describing how they were invented and their purpose of removing scatter radiation. It then covers topics like grid construction, terminology, styles, evaluation methods and common positioning errors that can cause cutoff. Different grid patterns, focal ranges and selection criteria are outlined. While grids improve image contrast by reducing scatter, their use also increases patient dose and technical factors. The document provides an overview of grids and their role in controlling scatter in medical imaging.
CT artifacts can be caused by a variety of factors related to the physics of CT imaging, the patient, and hardware issues. Physics-based artifacts include beam hardening, which causes cupping and streak artifacts, as well as partial volume averaging and noise. Patient motion can also cause artifacts. Hardware issues like ring artifacts may occur from problems with the x-ray tube. Proper use of filters and reconstruction techniques can help reduce artifacts like beam hardening, while keeping the patient still can minimize motion artifacts. Artifacts need to be understood as they can obscure anatomy or be mistaken for pathology.
The document discusses contrast media reactions, categorizing them as mild, moderate or severe. It describes types of reactions including anaphylactoid, non-anaphylactoid, chemotoxic, vasovagal and combined reactions. Factors that influence reactions are discussed such as physical properties of contrast media, iodine concentration, total volume, injection speed and patient risk factors. Prevention strategies and safer selection of low-osmolar nonionic contrast is emphasized.
This document summarizes various types of artifacts that can occur in MRI images and their causes and remedies. It discusses artifacts related to patient motion like respiratory and cardiac motion as well as metal implants. It also covers susceptibility artifacts at tissue interfaces, chemical shift artifacts at fat-water boundaries, and partial volume artifacts due to large voxel sizes. Specific artifacts discussed include black lines, zebra stripes, and Moire fringes. For each artifact, the document describes techniques that can be used to reduce or eliminate the artifact, such as breath holding, gating, and improved pulse sequences.
This document discusses the anatomy, imaging, and clinical evaluation of the salivary glands. It describes the major and minor salivary glands and lists common salivary gland complaints such as sialolithiasis, infection, Sjogren's syndrome, and tumors. Imaging modalities for evaluating salivary glands are discussed, including intraoral radiography, sialography, ultrasound, CT, MRI, scintigraphy, and sialendoscopy. The document provides examples of how various salivary gland pathologies appear on different imaging tests.
Diagnostic imaging in head and neck pathologyHayat Youssef
This document provides an overview of various diagnostic imaging modalities used in head and neck pathology including their history, principles, applications, advantages, and limitations. It discusses x-ray imaging techniques like conventional radiography and tomography. It also covers computed tomography, cone beam computed tomography, magnetic resonance imaging, ultrasound imaging, and nuclear imaging techniques like scintigraphy, positron emission tomography, and single photon emission tomography. Each imaging modality is described in terms of its basic principles, clinical applications in head and neck cases, benefits, and shortcomings. The document serves as a comprehensive reference for radiologists on diagnostic tools available for evaluating head and neck conditions.
Presentation1.pptx, radiological imaging of salivary glands diseases.Abdellah Nazeer
This document discusses various imaging modalities used to assess salivary gland diseases including plain film radiography, sialography, CT scan, MRI, diagnostic ultrasound, and nuclear scintigraphy. It provides details on the techniques and findings of each modality. The imaging plays an important role in evaluating symptoms, differentiating lesions, and determining extent of disease. Common diseases discussed include sialadenitis, sialolithiasis, mumps, HIV-related lesions, ranula, lipoma, hemangioma, and Sjogren's syndrome.
This document provides an overview of ultrasound physics, transducers, and transducer jelly. It discusses the characteristics of sound waves including their generation through mechanical vibration and their transmission through solids, liquids, and gases. The history of ultrasound and piezoelectricity is summarized. Key ultrasound concepts like wavelength, frequency, propagation velocity, amplitude, and absorption are defined. The components and function of ultrasound transducers including the piezoelectric crystal and backing block are described. Finally, the properties and ingredients of transducer jelly used to couple the transducer to the skin are outlined.
Computerized tomography (CT) was pioneered by Godfrey Hounsfield and Allan Cormack in the 1970s. CT uses X-rays and computer processing to create cross-sectional images of the body. The first CT scanners used a translate-rotate design, while later generations used multiple detectors and spiral scanning for faster, more detailed imaging. Image reconstruction uses back projection to convert attenuation measurements into pixel values and display slices. CT provides excellent anatomical detail and is widely used for diagnosing conditions of the brain, blood vessels, lungs and other organs.
This document discusses various embolization agents used to occlude blood vessels. It begins by defining embolization as introducing substances into circulation to block vessels to arrest or prevent bleeding. The goals are adjuvant, curative, or palliative depending on the condition. Originally, autologous blood clot was used but it recanalizes quickly. Modern agents include gel foam, particles like PVA and embospheres, and coils which can be pushable, injectable, or detachable. The appropriate agent depends on the region and degree of occlusion needed. Liquid agents are also used. Coils are commonly used for aneurysms while particles are used for fibroids and tumors.
Basic physics of multidetector computed tomography ( CT Scan) - how ct scan works, different generations of ct, how image is generated and displayed and image artifacts related to CT Scan.
This document discusses imaging techniques used to evaluate the major salivary glands. It begins with an overview of the anatomy and histology of the parotid, submandibular, and sublingual salivary glands. It then describes various imaging modalities including plain film radiography, sialography, ultrasonography, scintigraphy, MRI, and CT. Sialography provides the clearest visualization of the branching ductal system and is useful for evaluating obstructions. The document outlines the procedure for sialography and provides examples of normal findings and pathological findings like calculi, ductal inflammation, and tumors.
Perfusion MRI (DSC and DCE perfusion techniques) for radiology residentsRiham Dessouky
This document provides an overview of perfusion weighted MR imaging techniques. It discusses three main types: dynamic susceptibility contrast (DSC) MR perfusion, dynamic contrast enhanced (DCE) MR perfusion, and arterial spin labeling (ASL) MR perfusion. DSC relies on signal loss from gadolinium contrast to measure parameters like relative cerebral blood volume (rCBV) and flow (rCBF). DCE uses T1 shortening effects of contrast to calculate permeability and perfusion. Both techniques are used to evaluate brain tumors and strokes by analyzing signal intensity curves. DCE is also used in breast MRI to classify enhancement curves and measure permeability with the Ktrans parameter.
MDCT Principles and Applications- Avinesh ShresthaAvinesh Shrestha
Multidetector CT (MDCT) is one of the most commonly used imaging modality in the field of Radiology. Development and advancement in MDCT has made it's application as a major component in diagnosis and treatment planning of multitude of disease across the planet. This presentation briefly describes its basic principle and it's wide variety of application in medical imaging.
This document summarizes MRI contrast agents. It discusses how contrast agents can directly or indirectly change tissue properties by altering proton density, T1, or T2 relaxation times. Contrast agents are classified as parenteral relaxivity agents that are positive or negative, or parenteral susceptibility agents that are paramagnetic, superparamagnetic, or ferromagnetic. Gadolinium is the most common paramagnetic contrast agent and shortens T1, increasing brightness on T1-weighted images. Iron oxide particles are negative contrast agents that cause T2 shortening and decreased signal. The document reviews safety considerations for contrast agents and potential adverse reactions.
MRI machines use magnetic fields, radio waves, and computers to detect properties of living tissue. The first MRI image of the human body was obtained in 1977 and detected cancer tissue. MRI requires a magnet to align nuclear spins, radio waves to excite the spins, magnetic field gradients for spatial encoding, and a computer system to form images. Stronger magnetic fields allow for higher resolution images. Electromagnets, resistive magnets, superconducting magnets, and permanent magnets can be used to generate magnetic fields, with superconducting magnets allowing the highest field strengths. Radiofrequency coils transmit the excitation signal and receive the emitted signal used to form images.
This document discusses various magnetic resonance imaging parameters and how they affect image contrast and quality. It describes intrinsic parameters like repetition time and echo time that modify tissue signal, and extrinsic parameters like field of view and slice thickness that influence data collection. For each parameter, it explains how changes affect T1 and T2 weighting, signal-to-noise ratio, spatial resolution, scan time, and other characteristics. Examples of images with different parameter values are also shown to demonstrate the effects.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
This document discusses salivary gland diseases. It begins by describing the normal anatomy and function of the major and minor salivary glands. It then discusses various diseases affecting the salivary glands including inflammatory conditions like sialadenitis, infections, salivary stones, cysts, tumors, and dysfunction. Specific conditions covered in more detail include mumps, sialolithiasis, Sjogren's syndrome, mucocele, necrotizing sialometaplasia, pleomorphic adenoma, Warthin's tumor, mucoepidermoid carcinoma, and adenoid cystic carcinoma. The document provides information on clinical features, diagnosis, and treatment for each condition.
Sialography is an x-ray examination of the salivary glands that involves injecting contrast media into the ducts to evaluate any abnormalities. It can detect issues like stones, lesions, or masses that may be obstructing the ducts and causing pain or inflammation. There are three major pairs of salivary glands - parotid, submandibular, and sublingual - which produce saliva. Sialography can be used to evaluate masses, stones, pain, functional disorders, and suspected obstructions or strictures of the salivary glands. The procedure involves injecting contrast media under fluoroscopy and taking x-ray images to view the flow of saliva and identify any ob
This document discusses grids used for scatter control in radiography. It begins with an introduction on grids, describing how they were invented and their purpose of removing scatter radiation. It then covers topics like grid construction, terminology, styles, evaluation methods and common positioning errors that can cause cutoff. Different grid patterns, focal ranges and selection criteria are outlined. While grids improve image contrast by reducing scatter, their use also increases patient dose and technical factors. The document provides an overview of grids and their role in controlling scatter in medical imaging.
CT artifacts can be caused by a variety of factors related to the physics of CT imaging, the patient, and hardware issues. Physics-based artifacts include beam hardening, which causes cupping and streak artifacts, as well as partial volume averaging and noise. Patient motion can also cause artifacts. Hardware issues like ring artifacts may occur from problems with the x-ray tube. Proper use of filters and reconstruction techniques can help reduce artifacts like beam hardening, while keeping the patient still can minimize motion artifacts. Artifacts need to be understood as they can obscure anatomy or be mistaken for pathology.
The document discusses contrast media reactions, categorizing them as mild, moderate or severe. It describes types of reactions including anaphylactoid, non-anaphylactoid, chemotoxic, vasovagal and combined reactions. Factors that influence reactions are discussed such as physical properties of contrast media, iodine concentration, total volume, injection speed and patient risk factors. Prevention strategies and safer selection of low-osmolar nonionic contrast is emphasized.
This document summarizes various types of artifacts that can occur in MRI images and their causes and remedies. It discusses artifacts related to patient motion like respiratory and cardiac motion as well as metal implants. It also covers susceptibility artifacts at tissue interfaces, chemical shift artifacts at fat-water boundaries, and partial volume artifacts due to large voxel sizes. Specific artifacts discussed include black lines, zebra stripes, and Moire fringes. For each artifact, the document describes techniques that can be used to reduce or eliminate the artifact, such as breath holding, gating, and improved pulse sequences.
This document discusses the anatomy, imaging, and clinical evaluation of the salivary glands. It describes the major and minor salivary glands and lists common salivary gland complaints such as sialolithiasis, infection, Sjogren's syndrome, and tumors. Imaging modalities for evaluating salivary glands are discussed, including intraoral radiography, sialography, ultrasound, CT, MRI, scintigraphy, and sialendoscopy. The document provides examples of how various salivary gland pathologies appear on different imaging tests.
Diagnostic imaging in head and neck pathologyHayat Youssef
This document provides an overview of various diagnostic imaging modalities used in head and neck pathology including their history, principles, applications, advantages, and limitations. It discusses x-ray imaging techniques like conventional radiography and tomography. It also covers computed tomography, cone beam computed tomography, magnetic resonance imaging, ultrasound imaging, and nuclear imaging techniques like scintigraphy, positron emission tomography, and single photon emission tomography. Each imaging modality is described in terms of its basic principles, clinical applications in head and neck cases, benefits, and shortcomings. The document serves as a comprehensive reference for radiologists on diagnostic tools available for evaluating head and neck conditions.
Presentation1.pptx, radiological imaging of salivary glands diseases.Abdellah Nazeer
This document discusses various imaging modalities used to assess salivary gland diseases including plain film radiography, sialography, CT scan, MRI, diagnostic ultrasound, and nuclear scintigraphy. It provides details on the techniques and findings of each modality. The imaging plays an important role in evaluating symptoms, differentiating lesions, and determining extent of disease. Common diseases discussed include sialadenitis, sialolithiasis, mumps, HIV-related lesions, ranula, lipoma, hemangioma, and Sjogren's syndrome.
This document provides an overview of ultrasound physics, transducers, and transducer jelly. It discusses the characteristics of sound waves including their generation through mechanical vibration and their transmission through solids, liquids, and gases. The history of ultrasound and piezoelectricity is summarized. Key ultrasound concepts like wavelength, frequency, propagation velocity, amplitude, and absorption are defined. The components and function of ultrasound transducers including the piezoelectric crystal and backing block are described. Finally, the properties and ingredients of transducer jelly used to couple the transducer to the skin are outlined.
Computerized tomography (CT) was pioneered by Godfrey Hounsfield and Allan Cormack in the 1970s. CT uses X-rays and computer processing to create cross-sectional images of the body. The first CT scanners used a translate-rotate design, while later generations used multiple detectors and spiral scanning for faster, more detailed imaging. Image reconstruction uses back projection to convert attenuation measurements into pixel values and display slices. CT provides excellent anatomical detail and is widely used for diagnosing conditions of the brain, blood vessels, lungs and other organs.
This document discusses various embolization agents used to occlude blood vessels. It begins by defining embolization as introducing substances into circulation to block vessels to arrest or prevent bleeding. The goals are adjuvant, curative, or palliative depending on the condition. Originally, autologous blood clot was used but it recanalizes quickly. Modern agents include gel foam, particles like PVA and embospheres, and coils which can be pushable, injectable, or detachable. The appropriate agent depends on the region and degree of occlusion needed. Liquid agents are also used. Coils are commonly used for aneurysms while particles are used for fibroids and tumors.
Basic physics of multidetector computed tomography ( CT Scan) - how ct scan works, different generations of ct, how image is generated and displayed and image artifacts related to CT Scan.
This document discusses imaging techniques used to evaluate the major salivary glands. It begins with an overview of the anatomy and histology of the parotid, submandibular, and sublingual salivary glands. It then describes various imaging modalities including plain film radiography, sialography, ultrasonography, scintigraphy, MRI, and CT. Sialography provides the clearest visualization of the branching ductal system and is useful for evaluating obstructions. The document outlines the procedure for sialography and provides examples of normal findings and pathological findings like calculi, ductal inflammation, and tumors.
Perfusion MRI (DSC and DCE perfusion techniques) for radiology residentsRiham Dessouky
This document provides an overview of perfusion weighted MR imaging techniques. It discusses three main types: dynamic susceptibility contrast (DSC) MR perfusion, dynamic contrast enhanced (DCE) MR perfusion, and arterial spin labeling (ASL) MR perfusion. DSC relies on signal loss from gadolinium contrast to measure parameters like relative cerebral blood volume (rCBV) and flow (rCBF). DCE uses T1 shortening effects of contrast to calculate permeability and perfusion. Both techniques are used to evaluate brain tumors and strokes by analyzing signal intensity curves. DCE is also used in breast MRI to classify enhancement curves and measure permeability with the Ktrans parameter.
MDCT Principles and Applications- Avinesh ShresthaAvinesh Shrestha
Multidetector CT (MDCT) is one of the most commonly used imaging modality in the field of Radiology. Development and advancement in MDCT has made it's application as a major component in diagnosis and treatment planning of multitude of disease across the planet. This presentation briefly describes its basic principle and it's wide variety of application in medical imaging.
This document summarizes MRI contrast agents. It discusses how contrast agents can directly or indirectly change tissue properties by altering proton density, T1, or T2 relaxation times. Contrast agents are classified as parenteral relaxivity agents that are positive or negative, or parenteral susceptibility agents that are paramagnetic, superparamagnetic, or ferromagnetic. Gadolinium is the most common paramagnetic contrast agent and shortens T1, increasing brightness on T1-weighted images. Iron oxide particles are negative contrast agents that cause T2 shortening and decreased signal. The document reviews safety considerations for contrast agents and potential adverse reactions.
MRI machines use magnetic fields, radio waves, and computers to detect properties of living tissue. The first MRI image of the human body was obtained in 1977 and detected cancer tissue. MRI requires a magnet to align nuclear spins, radio waves to excite the spins, magnetic field gradients for spatial encoding, and a computer system to form images. Stronger magnetic fields allow for higher resolution images. Electromagnets, resistive magnets, superconducting magnets, and permanent magnets can be used to generate magnetic fields, with superconducting magnets allowing the highest field strengths. Radiofrequency coils transmit the excitation signal and receive the emitted signal used to form images.
This document discusses various magnetic resonance imaging parameters and how they affect image contrast and quality. It describes intrinsic parameters like repetition time and echo time that modify tissue signal, and extrinsic parameters like field of view and slice thickness that influence data collection. For each parameter, it explains how changes affect T1 and T2 weighting, signal-to-noise ratio, spatial resolution, scan time, and other characteristics. Examples of images with different parameter values are also shown to demonstrate the effects.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
This document discusses salivary gland diseases. It begins by describing the normal anatomy and function of the major and minor salivary glands. It then discusses various diseases affecting the salivary glands including inflammatory conditions like sialadenitis, infections, salivary stones, cysts, tumors, and dysfunction. Specific conditions covered in more detail include mumps, sialolithiasis, Sjogren's syndrome, mucocele, necrotizing sialometaplasia, pleomorphic adenoma, Warthin's tumor, mucoepidermoid carcinoma, and adenoid cystic carcinoma. The document provides information on clinical features, diagnosis, and treatment for each condition.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
This document provides an overview of salivary glands and saliva. It discusses the development, growth, classification and structure of major and minor salivary glands. It describes the secretion of saliva through parasympathetic and sympathetic stimulation. The document also outlines the composition and functions of saliva, as well as diseases associated with alterations in salivary secretion such as hypo-secretion and hyper-secretion. Finally, it discusses the applied diagnostic imaging and uses of saliva as a diagnostic aid.
Temporomandibular joint imaging 2 /certified fixed orthodontic courses by Ind...Indian dental academy
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This document summarizes the classification of osseous defects caused by periodontal disease. It describes different types of horizontal bone loss including osseous craters and bulbous bony contours. It also discusses vertical/angular bone loss and classifications proposed by Glickman and Goldman/Cohen. Furcation involvement is classified using scales proposed by Glickman and Tarnow/Fletcher. Understanding the nature of these bone alterations is important for effective diagnosis and treatment planning.
This document discusses radiological investigations of the gastrointestinal tract. It lists the basic investigations as plain X-ray abdomen, ultrasound, contrast fluoroscopic studies like barium swallow and barium meal, CT scan, MRI, and gamma camera imaging. It focuses on contrast fluoroscopic studies, describing barium swallow, barium meal, small bowel contrast studies of barium follow through and enteroclysis, and barium enema to identify pathologies in the gastrointestinal tract.
Sialography is an imaging technique used to visualize the salivary glands by injecting radiopaque contrast material into the ducts. It can be used to detect blockages like calculi, assess the extent of ductal and glandular damage, and locate masses. Iodine-based contrast agents provide better contrast while oil-based options are less radiopaque. The procedure involves locating the duct opening, inserting a cannula, injecting contrast medium, and having the patient rinse their mouth to expel the material. Pathologies have distinguishing appearances like sialadenitis resembling an apple tree in blossom.
this ppt depicts pattern of bone destruction. its a very good slide show showing the process of bone formation, bone destruction and their patterns in periodontal diseases.
The document discusses various diagnostic procedures used in gastrointestinal (GIT) diseases. It describes structural tests like imaging techniques (X-rays, ultrasound, CT, MRI, endoscopy), functional tests (motility tests, pH monitoring, malabsorption tests), tests for infections like Helicobacter pylori, blood tests, and stool tests. Key diagnostic procedures mentioned include upper and lower endoscopy, capsule endoscopy, ERCP, EUS, biopsy, and hydrogen breath testing.
Radiographic anatomy of gastrointestinal tractairwave12
This document provides an overview of how to interpret abdominal x-rays. It discusses the common views taken, important anatomical structures to evaluate, and what various findings may indicate. Key details include identifying the densities seen on x-rays, inspecting films with transmitted light, and assessing structures like the liver, kidneys, bowel loops and psoas muscles. Contrast agents like barium are also outlined for better defining certain structures.
This document discusses various radiographic techniques used to image the temporomandibular joint (TMJ), including:
1. Plain radiography, panoramic radiography, and tomography which image bone structure but not soft tissues.
2. Arthrography and MRI allow visualization of soft tissues like the meniscus within the TMJ.
3. Computed tomography can detect disorders like internal derangement by identifying abnormal increases in soft tissue density anterior to the condyle caused by an anteriorly displaced meniscus.
This document discusses various contrast agents used in medical imaging. It begins by defining contrast agents and describing their classification. It then focuses on water soluble iodinated contrast agents, describing their physiology and classifications including conventional high osmolar agents, low osmolar agents, and iso-osmolar agents. The document also discusses ultrasound contrast agents, their generations and mechanisms of action. It concludes by covering MR contrast agents such as gadolinium chelates and their uses and properties.
The document discusses contrast agents used in medical imaging, including desirable properties like safety and effectiveness, types such as positive iodine-based and negative air/gas agents, administration methods, and examples of examinations. Adverse effects are outlined for different contrast media based on properties like osmolality and ionicity. The ideal contrast agent is described as having high solubility, stability, biocompatibility, and selective excretion with minimal adverse impacts.
This document discusses contrast agents used in medical imaging. It begins by outlining the aims of discussing contrast agents, including why they are used and desirable features. The main types of contrast agents are then described - positive contrast agents like iodine and barium sulfate which increase attenuation, and negative contrast agents like air which decrease attenuation. Methods of administration and examples of examinations using contrast are provided. Risks associated with contrast agents like reactions and nephrotoxicity are also summarized.
This document discusses contrast media used in radiology. It introduces positive and negative contrast media, which increase or decrease density during imaging. Positive contrast agents contain iodine, bromine or barium, while negative agents include air, carbon dioxide and oxygen. Contrast media is classified as ionic or non-ionic, with ionic further divided into high- and low-osmolar types based on iodine concentration. Non-ionic agents have lower osmolality and are less likely to cause negative reactions in patients. The document outlines advantages like improved visualization but also disadvantages like possible aspiration if inhaled.
This document discusses different types of contrast agents used in medical imaging. It describes:
1. Positive contrast agents like iodine and barium that appear white on images as they attenuate x-rays more than soft tissue. Negative contrast agents like air and CO2 appear dark as they attenuate x-rays less.
2. Iodinated contrast agents are most commonly used. They are classified as high-osmolar ionic monomers, low-osmolar ionic dimers and non-ionic monomers/dimers based on their molecular structure and osmolarity.
3. Important factors for contrast agents include water solubility, stability, biocompatibility, and renal excretion.
Contrast agents allow for better visualization of internal body structures on CT scans. They are classified as ionic or nonionic, and as monomers or dimers. Contrast is administered orally, rectally, or intravenously depending on the area of interest. The distribution and timing of contrast enhancement is dependent on vascular anatomy and flow. Optimizing the contrast dose, injection rate, and timing of scans based on the clinical question is important for diagnostic accuracy.
Contrast agents are substances used in radiography to improve visualization of internal structures. They can be radiopaque (positive contrast) or non-radiopaque (negative contrast). Iodinated contrast media are commonly classified based on their ionicity, osmolality, and viscosity. Low osmolar contrast media including non-ionic dimers and monomers are preferred due to their favorable safety profile. Ultrasound contrast agents contain microscopic gas-filled bubbles that strongly reflect ultrasound waves, increasing echogenicity and tissue contrast.
Iodinated contrast media are widely used in radiology to enhance images. They ideally have properties like water solubility, stability, and safety. Contrast agents have evolved from early sodium iodide to include low and iso-osmolar agents. They are excreted renally and can interact with other drugs. Guidelines recommend using the lowest necessary dose and selecting low-osmolar media for high-risk patients. While generally safe, adverse reactions still occur occasionally and require prompt treatment.
Basic principles of Radiological anatomy.pptx pptx.pptxSundip Charmode
This document provides an overview of basic principles of radiology. It discusses various imaging techniques including X-rays, computed tomography, ultrasound, and magnetic resonance imaging. It describes how each technique works, its advantages and disadvantages, and examples of its clinical applications. The document also covers specialized radiographic procedures like angiography, mammography, and contrast studies of organ systems.
Contrast media are agents used to improve visualization of internal structures in medical imaging. They work by increasing the contrast between tissues. Contrast media can be classified as positive or negative based on whether they appear bright or dark on images. The main types of contrast media used are barium sulfate for x-rays and iodinated compounds for CT and angiography. Ultrasound contrast agents contain microbubbles that enhance backscatter and improve tissue contrast on ultrasound images. They allow better evaluation of organ perfusion and detection of abnormalities. Contrast media are important tools that improve diagnostic accuracy in medical imaging.
Here are the key steps in administering intravenous contrast media safely:
- Obtain informed consent
- Check for allergies and reactions to previous contrast administrations
- Consider risk factors like renal impairment, diabetes, or cardiac conditions
- Use low-osmolar contrast for high-risk patients
- Monitor vital signs during and after injection
- Have resuscitation equipment and medications available in case of reaction
Contrast media and medical imaging part 1Gopal Panda
Medical imaging uses contrast agents to improve visualization of internal organs and tissues. Contrast agents work by absorbing or altering electromagnetic waves or ultrasound, enhancing the contrast between tissues in images. India has a large and varied radiology market to serve its large population, but relatively few radiologists per capita. The major modalities used are X-ray, ultrasound, CT, and MRI. Contrast agents improve visibility of structures for these modalities. The most common types are iodine-based agents for X-ray and gadolinium for MRI; ultrasound uses microbubbles. Iodine-based agents are classified based on iodine concentration and osmolarity.
Contrast media are agents used to improve visualization of internal structures that otherwise cannot be seen clearly. There are two main types - positive contrast agents that are radiopaque, and negative contrast agents that are not. Iodinated contrast media are most commonly used today. They can be ionic monomers, ionic dimers, non-ionic monomers or non-ionic dimers. The ideal contrast medium has high solubility, stability, low toxicity and viscosity, and is excreted selectively like by the kidneys. Ultrasound contrast agents contain microbubbles that enhance echogenicity and improve tissue contrast. They act by resonating within the ultrasound beam. Newer agents use more stable low solubility gases and encapsulation to increase
Contrast radiography uses X-rays and a special dye called a contrast medium to study organs. This test allows radiologists to evaluate structures not clearly seen on regular X-rays. The contrast medium highlights specific body areas like blood vessels, the stomach, and colon, helping them be seen more clearly on X-ray images. Contrast materials temporarily change how X-rays interact with the body, making certain tissues appear different to help physicians diagnose conditions.
A brief of contrast media used in various modalities of radiodiagnosis including barium, USG, CT, and MRI with their advantages and disadvantages and ADR.
1. The document describes the scheme of evaluation for a course on radiographic techniques for special procedures. It provides details on three questions that will be asked, worth a total of 10 marks each, on topics like contrast media, contrast reactions, and barium swallow and enema procedures.
2. The questions cover iodinated contrast media classifications, types of contrast reactions and their mechanisms, and techniques for barium swallow and single and double contrast barium enema exams.
3. Scoring is broken down by specific criteria for each question, such as explaining contrast media chemistry or outlining the indications and contraindications for barium swallow.
This document describes several examples of biosensors. It discusses how antibodies are commonly used as recognition elements in biosensors, such as pregnancy tests. It also describes how glucose biosensors use the enzyme glucose oxidase to detect glucose levels in blood, enabling diabetes management. Finally, it summarizes an engineered nanopore biosensor that can detect specific DNA sequences by monitoring changes in electrical current as DNA binds within the nanopore.
This document discusses contrast media used in radiology. It describes radiolucent and radiopaque materials, different types of contrast agents including barium, iodinated, and gas-based agents. It discusses water-soluble, ionic, and nonionic contrast agents. It also outlines both common mild adverse effects and more severe life-threatening reactions that can potentially occur with the administration of contrast media.
Radiographic contrast media were developed starting in the late 19th century to increase differences in tissue attenuation and improve organ visualization on radiographs. The first effective contrast agents used barium and iodine compounds. Modern contrast media are tri-iodinated benzene derivatives that are either ionic or non-ionic, and monomeric or dimeric in structure. They carry risks of both idiosyncratic and non-idiosyncratic adverse reactions that depend on their osmolality, viscosity, and other properties. Appropriate use and precautions seek to minimize risks while maximizing diagnostic value.
Similar to Contrast rad sem / dental implant courses (20)
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This document discusses dental occlusion concepts and philosophies for complete dentures. It introduces key terms like physiologic occlusion and defines different occlusion schemes like balanced articulation and monoplane articulation. The document discusses advantages and disadvantages of using anatomic versus non-anatomic teeth for complete dentures. It also outlines requirements for maintaining denture stability, such as balanced occlusal contacts and control of horizontal forces. The goal of occlusion for complete dentures is to re-establish the homeostasis of the masticatory system disrupted by edentulism.
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This document discusses dental casting investment materials. It describes the three main types of investments - gypsum bonded, phosphate bonded, and ethyl silicate bonded investments. For gypsum bonded investments specifically, it details their classification, composition including the roles of gypsum, silica, and modifiers, setting time, normal and hygroscopic setting expansion, and thermal expansion. It provides information on how the properties of gypsum bonded investments are affected by their composition. The document serves as a comprehensive overview of dental casting investment materials.
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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
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Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
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Macroeconomics- Movie Location
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Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
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In an education system, it is understood that assessment is only for the students, but on the other hand, the Assessment of teachers is also an important aspect of the education system that ensures teachers are providing high-quality instruction to students. The assessment process can be used to provide feedback and support for professional development, to inform decisions about teacher retention or promotion, or to evaluate teacher effectiveness for accountability purposes.
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Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
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Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
2. • Contrast is the difference in image density
appearing on a radiograph
,representing various degrees of beam
attenuation.
(Langland &
Langlias)
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3. • Contrast radiography is exaggerating
the differences in density of tissues or
organs or Intraluminal filling defects,
usually by the introduction of contrast
agents.
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5. • Contrast agents, also known as contrast media, often
are used during medical imaging examinations to
highlight specific parts of the body and make them
easier to see.
• Contrast agents are administered in different ways:
Some are given Orally, others are injected or delivered
through an Intravenous Line or an Enema.
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6. • After the examination, some contrast agents are
harmlessly absorbed by the body.
• Others are excreted through the urine or bowel
movements.
• Contrast agents are not dyes; they do not permanently
discolour internal organs.
• Instead, they temporarily change the way x-rays or other
imaging tools interact with our body.
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7. CONTRAST MEDIACONTRAST MEDIA::
•Substances that increase contrast between
specific structure and background thus
improve conspicuity of structure and enable
improved evaluation ..
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8. BRIEF HISTORY
• In 1863, Walter Bradford Cannon, a UnitedIn 1863, Walter Bradford Cannon, a United
States physician, found that aStates physician, found that a BismuthBismuth
compound could be used to create images ofcompound could be used to create images of
the digestive tract.the digestive tract.
He developed a method of examining theHe developed a method of examining the
gastrointestinal system usinggastrointestinal system using BariumBarium
compound.compound.
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9. Ideal requirements of Contrast Media:
Safe to use and handle.
Non-toxic.
Should be removed from the body easily.
Should be stable in the body and in storage.
Should not have any side effects.
Should not penetrate the Blood Brain Barrier.
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10. Their transfer to the breast milk and placentral
passage should be limited.
Viscosity should be within acceptable limits to allow
easy and rapid injection.
Should have no adverse reactions.
Should not be very expensive.
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11. Why contrast media are necessary
• Different tissues within the body attenuate
the beam of X-rays to different degrees.
• The degree of attenuation of an X-ray
beam by an element is complex, but one of
the major variables is the number of
electrons in the path of the beam with
which it can interact.
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12. • In a complex mixture of elements, which
is what we are concerned with in the
organs of a patient, the degree of
attenuation is particularly influenced by
the average of the atomic numbers of all
the atoms involved.
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13. • Where there is a considerable difference
between the densities of two organs,
such as between the solid muscle
of the heart and the air in the
lungs, then the outlines of the structures
can be visualised on a radiograph
because of the Natural contrast that
exists.
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14. • Similarly, if there is a difference between the
average atomic numbers of two tissues, such as
between soft tissues, which are composed of
elements of Low Atomic Number and Bone,
which is partly composed of the element
Calcium, with a rather higher atomic number,
then the outlines of the different structures can
be seen by Natural contrast.
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15. • However, if the two organs have similar
densities and similar average atomic numbers,
then it is not possible to distinguish them on a
radiograph, because no natural contrast
exists.
• This situation commonly occurs in diagnostic
radiography, so that, for example, it is not
possible to identify Blood Vessels within an
organ.
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16. • Two of the factors important in organ contrast that can
be artificially altered are the density of an organ, and,
more usefully, the average atomic number of a
structure.
• The density of a hollow organ can be reduced by filling
it with gas or air, providing negative contrast.
Ex: gas is introduced into the stomach or colon during
a double-contrast Barium examination.
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17. • The average atomic number of hollow structure such as
a Blood Vessel can be increased by filling the cavity with
a liquid of much higher average atomic number (such as
iodine containing contrast medium) than that of Blood.
• This is the principle by which contrast media consist of
solutions or suspensions of non-toxic substances that
contain a significant proportion of elements of high
atomic number, usually iodine.
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19. D.H. Charr (1988) classified contrast media
into various types:
1.Depending on the nature of material
a. Iodine based
b. Non-Iodine based Eg. Barium Sulphate
2. Depending on the solvent
a. Conventional Ionic water soluble
b. Oil Soluble
Classification
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20. 3. Depending on the ionic nature:
a. Mono acidic monomer
Ex. Diatrizoate, Iothalurate
b. Non-ionic monomer
Ex. Iopamidol, Iohexol, Ioversol
c. Mono acidic dimer
Ex. Hexabrix
d. Non-Ionoic dimer
Ex. Iodixanol, Iotrol.
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21. Whaites E. (1996) classified contrast media as :
1. Barium Sulphate suspension for investigation of
GIT
2. Iodine based aqueous solution used for all other
investigations and divided them into:
a. Ionoic monomers,
Ex. Iothalamate, Metrizoate, Diatrizoate
b. Ionic dimers,
Ex. Ioxaglate
c. Non-ionic monomers
Ex. Iopamidol, Iohexol
3. Iodine based oil solutions.
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22. Negative contrast media
Air: Procedures which used air as C.M include -
Arthrography
Ventriculography
Bronchography etc.
• Advantage over gases (Co2 & O2 ) –
slowly absorbed from the injection site giving more time
for imaging.
Complications : Air embolism
• Also used in double contrast studies of the GIT(such as
barium enema).
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23. Mode of action
• Gas displaces, rather than mixing with the Blood & they
act as a negative C.M.
• It rapidly dissolves in the blood and is excreted as it
passes through the lungs.
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24. Advantages of CO2 over iodinated
contrast media :
• Absence of both nephrotoxicity & allergic reactions.
• Can be used in pt with previous reaction to ICM & in
asthmatics & Pts with impaired renal function
• Unlimited volume of CO2 can be delivered in multiple low
volume injections.
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25. Adverse Reactions
According to Ansell(1970):
Minor reactions:
• Nausea, mild vomitting,feeling of heat, limited
urticaria, pain, sneezing, mild pallor, sweating.
Intermediate reactions:
• Giddiness, severe vomitting, extensive
urticaria, Edema of face/glottis, Bronchospasm,
dyspnoea, chest/head/abdominal pain,
thrombophlebitis, thrombosis.
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26. Major reactions:
• Loss of consciousness.
• Cardiac arrest / Arryhythmias,
• Pulmonary edema,
• Pulmonary embolus.
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29. Grade 2 and grade3
reactions
• Skin reactions-if severe pruritis-
Diphenhydramine(50mg).
• Severe diffuse Erythema or Angioedema-
antihistamines.
• If still no response-Adrenaline,0.1-0.3ml
S.C.(1in1000)
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30. Respiratory reactions-
• Laryngeal edema-O2, adrenaline,intubation
• Bronchospasm-
Mild- O2 10lit/min
Salbutamol(inhaler)
Moderate-
Adrenaline: 0.1-0.3ml s.c.
and repeated after 10-15 min
Severe- adrenaline I.v
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32. Hypotension with Bradycardia-
• Mild-
O2 10lit/min
Isotonic I.v.fluids
• Severe -
Atropine0.6mg-1mg
I.v.slowly(repeat 3-5 times; Max dose-3mg)
Hypotention with Tachycardia-
Severe -adrenaline 1-3 ml(1-10000),i.v.upto
10ml or dopamine.
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33. Seizures or convulsions :
• Mild –turn the patient to one side to
prevent aspiration.
Clean the airway.
O2 10 ml/min.
• Severe-diazepam 5mg i.v. slowly
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35. IODINE, the preferred element in the radiological
contrast media because-
• High atomic number=53,produces high contrast
density
• Low toxicity
• Relatively safe.
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36. Classification of ICM
There are 4 chemical varieties of iodinated RCM in clinical
use
1. Ionic monomer:
Ex: Diatrizoate, Iothalamate
2. Nonionoic monomer:
Ex: Iohexol, Iopromide
3. Ionoic dimer:
Ex: Ioxaglate
4. Nonionoic dimer
Ex: Iodixanol
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37. • Total iodine content in the body is 50mg.
• Very large amounts of iodine are necessary because of
the low sensitivity in conventional photographic film-
screen radiography.
• Alternative non-photographic X-ray detection recording
systems like CT are much more sensitive to minor
differences in iodine concentration contrast.
DOSAGE OF IODINE
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38. •The average daily physiological turn over of iodine is
0.0001g.
• The total iodine content in the body (mainly in the
thyroid) is 0.01g.
• The requirement for a 2-, 3-, or 4-vessel angiogram (with
conventional film-screen recording) may be 70 g iodine
into the arterial supply trees of very sensitive organs, for
example the brain or heart.
• This is 700000 times the daily body turnover of iodine .
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39. •This huge quantity of iodine can be accepted by
the body with very rare evidence of severe toxicity.
• As the iodine content of the contrast medium
molecule is about 50% by weight, approximately
140g of contrast agent may be required in a
multivessel angiographic study.
• Probably the largest quantity of any drug used
intravascularly in the whole of clinical medicine.
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40. DIFFERENCES B/W OIL BASED
CM AND WATER SOLUBLE CM
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41. CONTRAST STUDIES:
• These investigations use contrast media,
radiopaque substances that have been developed
to alter artificially the density of different parts of
the patient, so altering subject contrast — the
difference in the X-ray beam transmitted through
different parts of the patient's tissues.
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42. Thus, by altering the patient, certain organs, structures and
tissues, invisible using conventional means, can be
seen.
Contrast studies, and the tissues imaged, include:
• Sialography — salivary glands
• Arthrography — joints
• Angiography — blood vessels
• Lymphography — lymph nodes and vessels.
• Urography — kidneys
• Barium swallow, meal and enema — GI tract.
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43. Main contrast studies used in the head and neck:
These include:
• Sialography
• Arthrography
• Angiography — this involves the introduction of aqueous
iodine-based contrast media into selected blood vessels.
(In the head and neck region, this involves usually the carotids
(common, internal or external) or the vertebral arteries.
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44. • Sialography can be defined as the radiographic
demonstration of the major salivary glands by
introducing a radiopaque contrast medium into their
ductal system.
• It is also very effective for the diagnosis of obstruction
whether caused by stones or strictures.
• It is widely used and is probably still the most common
specialized salivary gland investigation.
Sialography
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45. An ideal sialographic contrast media should have the
following characteristics:
i.Physiological properties similar to that of saliva,
ii. Miscibility with saliva.
iii. Absence of local or systemic toxicity.
iv. Pharmacological inertness
v. Satisfactory opacification.
vi. Low surface tension and low viscosity to allow filling
of fine components of the ductal system.
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46. vii. Easy elimination, but should be durable for sufficient time
so as to permit time for satisfactory radiographs
viii. Residual contrast media should be absorbed by the
salivary gland and detoxified by the liver or excreted by the
kidney
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47. • The procedure is divided into three
phases.
1.The Preoperative phase
2.The Filling phase
3.The Emptying phase
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48. Prophylactic measures to minimize
complications
• Use of low osmolality contrast agents
• Skin pre-testing.
• Prophylactic steroids
• Prophylactic Antihistamines
• Reassurance to reduce levels of anxiety
• Ask specifically about previous history of
iodine allergy.
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49. Preoperative phase :
This involves taking preoperative (scout) radiographs, if
not already taken, before the introduction of the contrast
medium, for the following reasons:
• To note the position and/or presence of any
radiopaque obstruction
• To assess the position of shadows cast by
normal anatomical structures that may overlie
the gland, such as the hyoid bone
• To assess the exposure factors.
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50. Filling phase:
• The relevant duct orifice needs to be found clinically,
probed and dilated, and then cannulated.
• The contrast medium can then be introduced.
• Three main techniques are available for introducing the
contrast medium, as described later.
• When this is complete, the filling phase radiographs are
taken.
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52. Emptying phase:
• The cannula is removed and the patient allowed to rinse
out.
• The use of lemon juice at this stage to aid excretion of
the contrast medium is often advocated.
• After five minutes, the emptying phase radiographs are
taken, usually lateral oblique . These films can be used
as a crude assessment of function.
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53. Contrast media used:
The types of contrast media suitable for sialography are all
iodine-based, and include:
Ionic aqueous solutions:
• Diatrizoate (Urografin®)
• Metrizoate (Triosil®)
Non-ionic aqueous solutions :
Iohexol (Omnipaque®)
• Iodized oil, e.g. Lipiodol® (iodized poppy
seed oil)
• Water-insoluble organic iodine compounds,
E.g. Pantopaque®.
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54. Main indications
The main clinical indications for sialography
include:
• To determine the presence and/or position of calculi or
other blockages.
• To assess the extent of ductal and glandular destruction
secondary to an obstruction .
• To determine the extent of glandular break-down and as
a crude assessment of function in cases of dry mouth.
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55. Contraindications:
The main contraindications include.
• Allergy to compounds containing Iodine although
Gadolinium may be used as an alternative.
• Periods of Acute infection/inflammation.
• when there is discharge of pus from the duct opening
• When clinical examination or routine radiographs have
shown a calculus close to the duct opening, as injection
of the contrast medium may push the calculus back
down the main duct where it may be inaccessible.
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56. SIALOGRAPHIC TECHNIQUES:
• The control of infection measures .
• Wearing of eye protection glasses and a mask by
operators is recommended.
• The three main techniques available for introducing the
contrast medium into the ductal system, having
cannulated the relevant duct orifice, include:
• Simple injection .
• Hydrostatic
• Continuous infusion pressure-monitored.
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57. Simple injection technique
• Oil-based or aqueous contrast medium is introduced
using gentle hand pressure until the patient experiences
tightness or discomfort in the gland, (about 1.0 ml for the
parotid gland, 0.8 ml for the submandibular gland).
Advantages:
• Simple Inexpensive.
Disadvantages:
• The arbitrary pressure which is applied may cause
damage to the gland .
• Relying on patient's responses may lead to
underfilling or overfilling of the gland.
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58. Hydrostatic technique:
• Aqueous contrast media is allowed to flow freely
into the gland under the force of gravity until the patient
experiences fulness or discomfort.
Advantages:
• The controlled introduction of contrast medium is less
likely to cause damage or give an artefactual picture.
• Simple
• Inexpensive.
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59. Disadvantages:
• Reliant on the patient's responses - Patients have to lie
down during the procedure, so they need to be
positioned in advance for the filling-phase radiographs.
Continuous infusion pressure-monitored technique:
Using aqueous contrast medium, a constant flow
rate is adopted and the ductal pressure monitored
throughout the procedure.
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60. • Each of these techniques has its advantages, and with
experience, each produces satisfactory results.
• The technique employed is therefore dependent on the
Operator and the Facilities available.
• In addition, Sialography may also be performed using
advanced imaging modalities,
Ex: CT Sialography and MR Sialography .
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61. Sialographic interpretation:
Essential requirements include:
• A systematic approach
• A detailed knowledge of the radiographic appearances of normal
salivary glands.
• A detailed knowledge of the pathological conditions affecting the
salivary glands.
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62. Systematic approach:
A suggested systematic approach for viewing sialographs
General overview of entire film
1 Note the shadows cast by overlying normal anatomical
structures, particularly:
• The spine
• The hyoid bone
• The mandible
2 Assess the exposure factors
The salivary gland
3 Assess the degree of filling of the duct structure
4 Assess the main duct, noting particularly: The diameter of the duct ,the
course and direction of the duct .The presence and position of any defects or
strictures.
5 Assess the duct structure within the gland, noting particularly: The
branching and gradual tapering of the minor ducts towards the periphery of the
gland The overall pattern and shape of the ducts The degree of overall glandular
filling The presence and positioning of any filling defects
6 Assess the degree of emptying
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63. Algorithm for diagnostic imaging of salivary
glands:
Plain film radiography,
Conventional sialography,
Computed Tomography (CT),
Magnetic Resonance Imaging (MRI),
Scintigraphy
Ultrasonography
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64. Normal sialographic appearances of the parotid gland:
• The main duct is of even diameter (1-2 mm wide) and
should be filled completely and uniformly.
• The duct structure within the gland branches regularly
and tapers gradually towards the periphery of the gland,
the so-called tree in winter appearance
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66. Pathological appearances:
Based on the suggested systematic approach to
sialographic assessment, the main pathological changes
can be divided into:
Ductal changes associated with:
• Calculi
• Sialodochitis (Salivary ductal inflammation)
Glandular changes associated with:
• Sialadenitis (Glandular Inflammation/
Infection)
• Sjogren's syndrome
• Intrinsic tumours.
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67. • Sialographic appearances of sialodochitis
include:
Segmented Sacculation or dilatation and stricture of
the main duct, the so called sausage link appearance.
Associated calculi or ductal stenosis.
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69. • Sialographic appearances of sialadenitis
include:
Dots or blobs of contrast medium within the gland, an
appearance known as sialectasis caused by the
inflammation of the glandular tissue producing saccular
dilatation of the acini .
• The main duct is usually normal
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70. Sialographic appearances in Sjogren's syndrome:
• Widespread dots or blobs of contrast medium within the
gland, an appearance known as punctate sialedasis or
snowstorm .
• This is caused by a weakening of the epithelium lining
the intercalated ducts, allowing the escape of the
contrast medium out of the ducts.
• Considerable retention of the contrast medium during the
emptying phase
• The main duct is usually normal
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71. The different stages of sialectasia in SS, as present on Lateral parotid sialograms
(A) Punctate sialectasia,
less than 1 mm in size;
(B) Globular Sialectasia, uniform of
shape and 1 to 2 mm in size;
(C) Cavitary sialectasia, irregular of
shape and more than 2 mm in size;
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74. Diagrams showing an intercalated Ductule and Acinus.
A In a normal gland.
B In Sjogren's syndrome, the epithelium lining the
intercalated ductule becomes weakened allowing escape of
the contrast medium out of the duct so producing the dots
or blobs.
C In sialadenitis, the acinus becomes dilated allowing the
collection of contrast into a dot or blob.
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75. Ba swallow test
One of the most commonly used contrast agents is Barium
sulfate.
Barium blocks the passage of x-rays, so barium-filled
organs stand out better on x-ray exams.
For an examination of the esophagus or stomach, patients
are asked to drink a mixture of barium sulfate and water,
sometimes with vanilla or fruit flavoring added.
This mixture usually is Thick and White.
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79. A 42-year-old woman with a chief complaint of an
asymptomatic swelling of the right nasolabial region present
for 10 years.
On the occlusal radiographic examination a distortion of the
anterior lateral wall of nasal cavity was observed.
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80. Aspiration of 3 ml of cystic fluid was performed with
a needle of 0.5 mm and a brown liquid was obtained.
Three millilitres of radiographic contrast medium (50%
sodium diatrizoat) was injected .
Occlusal and cephalometric radiographs were taken and a
3 cm radiopaque spherical image was observed in these
images
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83. Contrast media in Arthrography:
• Arthrography is a technique in which an indirect
image of the disk is obtained by injecting a
radiopaque contrast agent into one or both
spaces under Fluoroscopic guidance.
• In the Head and neck region this technique is
employed in TMJ is known as “TMJ
Arthrography”.
• Pass in 1939 accomplished the first use of
arthrography in evaulating the TMJ
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84. Indications:
• When information about disk position, function,
morphology, and the integrity of discal attachments
is required for treatment planning.
Contraindications:
• Allergy to contrast agent.
Disadvantages :
Invasiveness of the Technique.
Postoperative discomfort.
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85. • Injection of contrast
medium into the
lower joint space.
• Information about
joint dynamics.
• Recommended for
patients with primary
functional
disturbance such as
clicking and
intermittent locking.
Single contrast technique Double contrast techniques
• Injection of Contrast
medium and Air into both
upper and lower joint
spaces.
• Information about the joint
morphological features.
• Recommended to know
the morphological
Alterations of the joint.
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86. • Water-soluble contrast agents are preferred in
Arthrography because they provide enough
contrast to define Interior structures
• They also have advantage of being dissipated
quickly.
• Upper and lower joint compartments could be
passively filled with 1-2ml and 0.9ml respectively.
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87. Contrast media in
angiography
• Angiography includes Arteriography and Phlebography.
• For Arteriography, ideally require a medium that gives
good contrast, possess low viscosity (for rapidity of
injection) and is Nontoxic.
Most commonly used CM are:
• Sodium and Methylglucamine diatrizoate
• Metrizoate & Iohexol.
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88. • Gadodiamide and Super Paramagnetic iron oxide(SPIO)
can also be used.
• The normal external carotid carotid artery can be
opacified by 3-10ml of contrast medium.
• Low osmolarity and non-ionic contrast media are used
in phlebography or venography where it can be injected
by either direct puncture of the vein or indirectly by
injecting the medium into the arterial system and
imaging the venous return.
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90. Contrast Media in Computed Tomography(CT):
• CT images are analysed in terms of Normal versus
disturbed Anatomy.
• In CT the rationale for using contrast media is to obtain
a differential change in the attenuation values of normal
and pathological tissues, so that recognition of the
abnormality is facilitated.
• Lesions not obvious on simple scan can be revealed
and many others are enhanced by contrast medium
which depends on the pharmacokinetics of the contrsat
media
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91. • Most widely used material is 30mg of Iodine for an
average built and scanned after 5-15 min later.
• CT of the salivary glands was introduced as a new
technique in 1978.
• On CT scan, Normal Parotid Gland appears more radio
dense than adjacent fat but less dense than surrounding
muscles because of its high fat content and high
concentration of saliva.
• Submandibular gland contains less fat so its density is
similar to the adjacent muscles.
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92. Contrast agents for Magnetic Resonance
Imaging(MRI):
• MR contrast agents provide an alternative solution to
overcome some of the limitations of plain MR Imaging.
• Contrast agents alter the Tissue relaxation times and
can therefore be used to manipulate their Single
intensity.
• They are used to enhance soft tissue structures,
characterize the tissues non-invasively, portray
physiological process in vivo and reduce imaging time
easily.
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94. Contrast agents used in MRI are:
• Gadolinium based contrast agents:
a. Gadolinium-DPTA
b. Gadomer-17 SH L 643A
• Superparamagnetic iron oxide SH U 555C
• Ultrasmall Superparamagnetic iron oxide (USPIO).
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