Macroradiography is a radiographic technique used to magnify images relative to the object being imaged. It works by increasing the object-to-film distance, which magnifies the image size. Key factors that affect image quality include geometric unsharpness, which increases with magnification, and limitations of the x-ray tube's fine focal spot, which restricts output. Macroradiography is useful for examining small bony structures and pulmonary patterns at higher magnification.
this power-point slide presentation includes lots of information like how MRI coil works. what is shimming, magnet, fringe, and design of mri coil and also magnet. this will help a lot for radiologist and technician radiographers.. thanks.
Quality Assurance Programme in Computed TomographyRamzee Small
Introduction to Computed Tomography
Basic description of the components of a CT System
Introduction to Quality Assurance
Quality Assurance and Quality Control Tests in Computed Tomography base on frequency
Objective of QA/QC Test
this power-point slide presentation includes lots of information like how MRI coil works. what is shimming, magnet, fringe, and design of mri coil and also magnet. this will help a lot for radiologist and technician radiographers.. thanks.
Quality Assurance Programme in Computed TomographyRamzee Small
Introduction to Computed Tomography
Basic description of the components of a CT System
Introduction to Quality Assurance
Quality Assurance and Quality Control Tests in Computed Tomography base on frequency
Objective of QA/QC Test
Rad 206 p11 Fundamentals of Imaging - Control of Scatter Radiationsehlawi
Fundamentals of Imaging
This course will provide you with the principles involved in the formation and recording of the radiologic image in both conventional and digital imaging systems as well as the principles of image quality assessment.
Control of Scatter Radiation
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
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These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
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2. Table of Content
● What is macroradiography ?
● Principles of macroradiography
● Magnification factor
● Factors affecting image quality
○ Geometric unsharpness
○ X-ray tube rating
○ Photographic unsharpness
○ Scattered radiation
● Aim & applications of macroradiography
● References
● Questions
3. What is Macroradiography ?
● Macroradiography is a radiographic
imaging technique used to increase
the size of the image relative to the
object.
● In 1982 an Italian doctor named
Alessandro Vallebone proposed this
technique.
4. Principles of Macroradiography.
● A technique of producing an image by
direct magnification using an x-ray
tube with very fine focal spot.
● Focal spot-object distance will be
adequatly changed in accordance with
the change in accordance with the
change in magnification.
5. [Cotd…]
● Magnified image can be produced by increasing the object to film
distance from the point source.
● The required magnification is obtained by moving the object away from
the film.
6. [Cotd…]
● However, the geometric unsharpness increases with the increase of
magnification.
7. Magnification Factor
● The ratio of image size to object size is known as magnification factor. Its
value is normally assessed by measuring the focus - film distance (FFD)
and the object - film distance (OFD). the focus - object distance (FOD) is
then obtained by subtraction:
FOD = FFD - OFD
● Thus ,
Magnification factor = FFD/FFD-OFD=FFD/FOD
8. [Cotd…]
● For a routine examination of the hand (dorsipalmar projection), the
relevant dimensions are typically: FFD = I 00 cm, OFD = I cm. This gives
a magnification factor of 100/99 = 1.01. Thus, a 10 cm long finger gives an
image which is 10.1 cm in length.
● For a lateral projection of the lumbar spine, the relevant dimensions arc
typically: FFD = I 00 cm, OFD = 25 cm (spine-table-top distance + table-
top-film distance). This gives a magnification factor of 100/75 = 1.3. A true
measurement of 10 cm in the spine is reproduced as 13 cm in the image
9. [Cotd…]
● For macroradiography, it is usual to arrange the FFD and OFD to give a
magnification factor of at least 1.5. Typically, a magnification factor of2.0
is achieved by positioning the structure under examination half-way
between the X-ray tube focus and the film, i.e. FFD = FOD x 2 (sec Fig.
26.2). In practice, the FOD is often maintained at its normal value but the
FFD is increased, i.e. the X-ray tube and patient are positioned normally
hut the film is moved further from the patient.
10.
11. Factors affecting Image Quality
● The quality of the magnified image is also an important consideration,
which may be affected by modifications to the FFD, FOD and OFD.
● Geometrical factors involves,
○ Geometric Unsharpness
○ X-Ray tube rating
○ Photographic Unsharpness
○ Scattered radiation
12. Geometric Unsharpness
● Geometric unsharpness refers to the loss of sharpness of feature on
radiograph that correspond to the boundaries from thickness that result
of geometric factor of the radiographic equipment and setup.
● To reduce this the the point source focal spot used.
13. ● In the 1st image, radiation
originates at a very small
source, so very little geometric
unsharpness is produced in the
image.
● In the 2nd image, the source is
large & different path the rays
of radiation can take from their
point of origin in source that
cause the edges of the notch to
be less defined.
Source
Film
Film density
plot
14. Formulae of Geometric Unsharpness
● When the detector is not placed next to
sample, such as when the geometric
magnification is used then,
Ug = f . b/a
f = Source focal spot
a = Subject - Source distance
b = Subject - detector distance
Source focal spot
Subject
Detector
Penumbra
{Ug}
15. X_Ray Tube rating
● To limit geometric unsharpness and still achieve substantial
magnification requires the use of an ultrafine focus. Such a small focus
sets serious constraints on the output of the X-ray tube.
● This may well be manifested as a reduction in maximum tube current e.g.
from over 1000 mA on broad focus to less than 400 mA when fine focus
is selected, and consequently, exposure times become longer than
desirable. Unless great care is taken, motional unsharpness is the result.
Motional unsharpness problems can be alleviated by:
○ Taking positive measures to immobilize the patient;
○ Using fast film-screen systems, if necessary
16. [Contd…]
● Extremities is often highly successful because the required X-ray exposure
is small and effective immobilization is possible: thus, high-resolution
screens can be used.
● Macroradiography may prove impossible, e.g. for many abdominal
structures the large exposures necessary and the problems of involuntary
movement may exclude macroradiography as a viable technique.
● minimizing the FFD may ease rating problems but the radiographer must
be alert to the increased radiation dose to the patient associated with a
short focus-skin distance.
17. Photographic Unsharpness
● The resolution of the film or film-screen system is not normally a critical
limiting factor in carrying out macroradiography.
● Photographic unsharpness ( Up) remains constant because it is not the
recorded image that is magnified.
18. Scattered Radiation
● The large object-film distance used in macroradiography reduces the
amount of forward-scattered radiation reaching the film from the patient.
● It is not necessary to use a secondary-radiation grid, even for regions such
as the skull or spine where a grid would be essential.
● Collimation of the X-ray beam and provision of backscatter protection for
the film help to maintain optimum contrast on the macroradiograph.
19. Aim of Macroradiography.
● Aimed to improve the study of the bony structures and the
pulmonary designs.
● Allows the small detail obvious in the image.
Application of Macroradiography
● Carpal bones of the wrist (especially the scaphoid bone)
● Bones of hand, e.g., early detection of metabolic bone disease.
● Temporal bone.
● The lacrimal system during Dacryocystography.
● Nodular pattern in chest radiographs.
● Cerebral Angiography.
21. Questions ?
1. Whats are the 2 requirements of successful macroradiography ?
2. How is macroradiography is achieved ?
3. What is the main disadvantage of macroradiography ?
4. What is the formulae of geometric unsharpness ?
5. Who proposed macroradiography ?