The document discusses radiation hazards in orthopedic trauma care, including definitions of different types of radiation, how x-rays are produced, measurements of radiation exposure, effects of radiation like cancer and genetic mutations, and methods for radiation protection. Radiation can cause both stochastic effects like cancer that depend on probability as well as deterministic effects above a threshold that increase in severity with dose. Protecting patients and medical staff requires understanding radiation measurements, injuries, and factors that determine biological impacts.
This video explains Lumbar Disc Replacement in Detail. When degenerative disc disease begins to affect the spine this is called degenerative disc disease. This video highlights the history, epidemiology, and treatment options both conservative and surgical. If you or someone you know needs to be seen in regards to Lumbar Disc Replacement feel free to look us up online www.beverlyspine.com or www.santamonicaspine.com OR call toll free 1-8SPINECAL-1
This video explains Lumbar Disc Replacement in Detail. When degenerative disc disease begins to affect the spine this is called degenerative disc disease. This video highlights the history, epidemiology, and treatment options both conservative and surgical. If you or someone you know needs to be seen in regards to Lumbar Disc Replacement feel free to look us up online www.beverlyspine.com or www.santamonicaspine.com OR call toll free 1-8SPINECAL-1
Acetabular Fracture Radiology: Xrays, CT scan & 3D printingVaibhav Bagaria
The talk details how to assess various types of acetabular fracture. Combination of X-rays, CT Scan and 3D reconstruction and 3D printing also known as 3DGraphy. Basic 8 patterns and importance of various radiological parameter are explained.
The exact anatomy of the bones and joints is of great importance to the clinician when examining the limbs and to the surgeon when operating on the bones and joints.
To understand deformities of the extremities, it is important to first understand and establish the parameters and limits of normal alignment.
Each long bone has a mechanical and an anatomic axis
both frontal and sagittal planes axis lines are applicable to any longitudinal projection of a bone.
The corresponding radiographic projections are the anteroposterior (AP) and lateral (LAT) views, respectively.
Pain from acute vertebral fracture appears to be due in part to instability (non-union or slow union at the fracture site), while more than 1/3 of patients become chronically painful.
Traditional treatment for patients with painful VCFs includes bed rest, narcotic analgesics and bracing, resulting in increased pain because of acceleration bone loss and muscle weakness.
Orthopedics is a Reconstructive Surgery. Mangled extremity is an injury to at least three out of four systems (soft tissue, bone, nerves, and vessels). A Decision have to be made Amputation + Prosthesis Vs. Limb salvage procedure which includes Irrigation & Debridement, External fixation, Antibiotic bead spacers, Soft tissue coverage and finally Restoring Skeletal Stability by Salvage of Bone Defect
Acetabular Fracture Radiology: Xrays, CT scan & 3D printingVaibhav Bagaria
The talk details how to assess various types of acetabular fracture. Combination of X-rays, CT Scan and 3D reconstruction and 3D printing also known as 3DGraphy. Basic 8 patterns and importance of various radiological parameter are explained.
The exact anatomy of the bones and joints is of great importance to the clinician when examining the limbs and to the surgeon when operating on the bones and joints.
To understand deformities of the extremities, it is important to first understand and establish the parameters and limits of normal alignment.
Each long bone has a mechanical and an anatomic axis
both frontal and sagittal planes axis lines are applicable to any longitudinal projection of a bone.
The corresponding radiographic projections are the anteroposterior (AP) and lateral (LAT) views, respectively.
Pain from acute vertebral fracture appears to be due in part to instability (non-union or slow union at the fracture site), while more than 1/3 of patients become chronically painful.
Traditional treatment for patients with painful VCFs includes bed rest, narcotic analgesics and bracing, resulting in increased pain because of acceleration bone loss and muscle weakness.
Orthopedics is a Reconstructive Surgery. Mangled extremity is an injury to at least three out of four systems (soft tissue, bone, nerves, and vessels). A Decision have to be made Amputation + Prosthesis Vs. Limb salvage procedure which includes Irrigation & Debridement, External fixation, Antibiotic bead spacers, Soft tissue coverage and finally Restoring Skeletal Stability by Salvage of Bone Defect
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.
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
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.
Title: Sense of Taste
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 structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
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Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
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
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
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.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
4. RADIATION
Radiation, as defined as the emission and
propagation of energy through space or a
substance in the form of waves or
particles.
1. IONIZING RADIATION
2. NON-IONIZING RADIATION
5.
6. Ionizing Radiation
Ionizing radiation can be defined as radiation that is
capable of producing ions by removing or adding an
electron to an atom.
Ionizing radiation can be classified into two groups:
(1) particulate radiation
(2) electromagnetic radiation.
7. In this type, the energy is "packaged" in small
units known as photons or quanta.
Visible light, radio waves, and x-rays are
different types of EM radiation.
EM radiation has no mass, is unaffected by
either electrical or magnetic fields, and has a
constant speed in a given medium.
EM radiation is characterized by wavelength (λ),
frequency (v), and energy per photon (E)
EM RADIATION
8. The other general type of radiation consists of small
particles of matter moving through space at a very high
velocity.
Particle radiation differs from electromagnetic
radiation in that the particles consist of matter and
have mass.
Particle radiation is generally not used as an imaging
radiation because of its low tissue penetration.
ex. Electron, alfa particles.
Particulate Radiation
12. The x-ray tube.
The tube head consists
of a pair of electrodes.
- A negatively
charged cathode with
include a heater
filaments.
- A positively
charged a node with a
tungsten target.
13. Steps in x-ray production.
Filament is heated and gives off cloud of
electrons.
A large electrical charge is placed in the
cathode/anode space causing the electrons to
race toward the anode.
When they crush into the anode it causes x-ray
to be given off.
14. X-ray machine
components.
The tube head where the x-rays are
generated.
The control panel which regulate the
strength and amount of the x-rays
produced and trigger the exposure.
The power supply which provide the
energy to creates the x-rays.
15.
16.
17.
18. Control panel
Higher kv attract the electrons toward the
anode by greater force.
They smash the anode harder and produce x-ray
with higher energy and greater tissue penetrating
power.
Increasing mA increase the number of
electrons cloud around the filament. Result in
higher number of x-ray produced per second.
19.
20. X-ray film composition.
Polyester base that provide support has bluish
tint.
Film emulsion is a thin layer of chemicals
coating the base composed of.
- Light sensitive silver halide (mainly Bromide
AgBr) crystals.
- gelatins that keep the silver bromide grains
evenly dispersed.
23. RADIATION MEASUREMENTS
International Commission on Radiation Units and Measurement (ICRU) has
established special units for the measurement of radiation.
Such units are used to define four quantities of radiation:
(1) exposure/air.
(2) dose/tissue.
(3) dose equivalent.
(4)Radioactivity
At present, two systems are used to define radiation measurements:
(1) The older system is referred to as the traditional system, or standard system.
(2) the newer system is the metric equivalent known as the SI system.
24. EXPOSURE/AIR
EXPOSURE;The term exposure refers to the measurement of
ionization in air produced by x-rays.
Standard unit-Roentgen (R)
SI unit -Coulombs per kilogram (C/kg)
One roentgen is equal to the amount of radiation that produces
approximately two billion, or 2.08 × 10 9 , ion pairs in one cubic
centimeter (cc) of air.
25. DOSE/TISSUE
Dose can be defined as the amount of energy absorbed by a
tissue.
Standard unit-Radiation absorbed dose (rad)
SI unit -Gray (Gy)
26. DOSE EQUIVALENT
Different types of radiation have different effects on tissues.The
dose equivalent measurement is used to compare the biologic
effects of different types of radiation.
Standard unit-Roentgen equivalent (in) man (rem)
SI unit -Sievert (Sv)
27. RADIOACTIVITY
It is the process by which a nucleus of an unstable atom loses
energy by emitting ionizing radiation.
Standard unit-Curie(Ci)
SI unit -Becquerel(Bq)
1Curie is =3.7x1010 (37 Billion Bq)disintegrations per second.
1 Becquerel is = one disintegration per second.
DPS-The number of subatomic particles (e.g. alpha particles) or
photons (gamma rays) released from the nucleus of a given
28. The amount of radiation encountered in
daily life ranges in the dimension of
1Gy=1SV=1Joule/kg
100millirems=1mGy=1mSv.
29.
30. In the radiology dept........
Chest x-ray 0.1mSv
Ct head 1.5 mSv
Ct whole
body
9 - 13 mSv
The dose required to produce radiation
sickness is between 500 - 1000 msv,equivalent
to that amount citizens of Hiroshima were
exposed in 1945.
31. Regarding thyroid cancer,85% of
papillary carcinomas are radiation
induced
Carcinogenic dose being100 msv
Threshold value per year should not
exceed ,
1. 300 mSv for thyroid,
2. 150 msv for eye, and
3. 500 msv for hand
32. DURING IM NAILING HAND
RECIEVES 41.7MICROSV
DURING PLIF HAND RECIEVES
117 MICROSV
34. RADIATION INJURY
Radiation injury- tissue damage or changes caused by
exposure to ionizing radiation-namely, gamma and x-
rays such high-energy particles as neutrons, electrons,
and positrons.
In diagnostic radiography, not all x-rays pass through
the patient and reach the x-ray film; some are
absorbed by the patient’s tissues.
38. IONIZATION
Ionization is produced through the photoelectric effect or Compton
scatter and results in the formation of a positive atom and a dislodged
negative electron.
The ejected high-speed electron is set into motion and interacts with
other atoms within the absorbing tissues. The kinetic energy of such
electrons results in further ionization, excitation, or breaking of
molecular bonds, all of which cause chemical changes within the cell
that result in biologic damage
39. FREE RADICALS FORMATION
X-ray causes cell damage primarily through the formation of
free radicals. Free radical formation occurs when an x-ray
photon ionizes water, the primary component of living cells.
Ionization of water results in the production of hydrogen and
hydroxyl free radicals
A free radical is an uncharged (neutral) atom or molecule that
exists with a single, unpaired electron in its outermost shell.
41. Direct or Target Action
Theory
The direct theory of radiation injury suggests that cell
damage results when ionizing radiation directly hits
critical areas, or targets, within the cell.
For example, if x-ray photons directly strike the DNA
of a cell, critical damage occurs, causing injury to the
irradiated organism.
42. Indirect Action or Poison
Chemical Theory
x-ray photons are absorbed by the water within a cell, free
radicals are formed. These free radicals combine to form toxins.
(e.g., H 2 O 2 ), which cause cellular dysfunction and biologic
damage.
The chances of free radical formation and indirect injury are
great because cells contain 70% to 80% water.
45. Sequence of Radiation Injury
Chemical reactions (e.g., ionization, free radical formation) that follow the
absorption of radiation occur rapidly at the molecular level.
However, varying amounts of time are required for these changes
to alter cells and cellular functions.
As a result, the observable effects of radiation are not visible immediately
after exposure. Instead, following exposure, a latent period occurs.
A latent period can be defined as the time that elapses between exposure to
ionizing radiation and the appearance of observable clinical signs.
46. After the latent period, a period of injury occurs. A variety of cellular injuries
may result, including cell death, changes in cell function, breaking or clumping
of chromosomes, formation of giant cells, cessation of mitotic activity, and
abnormal mitotic activity.
The last event in the sequence of radiation injury is the recovery period. Not
all cellular radiation injuries are permanent. With each radiation exposure,
cellular damage is followed by repair. Depending on a number of factors, cells
can repair the damage caused by radiation.
If effects of radiation exposure are additive, the unrepaired damage accumulates
in the tissues. The cumulative effects of repeated radiation exposure can
lead to health problems (e.g., cancer, cataract formation, birth defects).
51. LATENT PERIOD
THE TIME LAPSE BETWEEN
EXPOSURE OF THE RADIATION
AND THE APPEARENCE OF THE
EFFECTS
51
52. MAXIMUM PERMISSIBLE DOSE
Greatest dose of radiation which is not expected to cause detectable
bodily injury to people at any time during their lifetime.
The amount of ionizing radiation a person may be exposed
to supposedly without being harmed
For radiology workers and surgeons this limit for the whole body is
50 mSv.
53. median lethal dose
The amount of ionizing radiation that
will kill 50 percent of a population in a
specified time
Abbreviation: LD50
55. Stochastic effects
Stochastic effects are those that may develop.Their development
is random and depends on the laws of chance or probability.
Examples of somatic stochastic effects include leukaemia and
certain tumours.
These damaging effects may be induced when the body is
exposed to any dose of radiation.
It is therefore assumed that there is no threshold dose, and that
every exposure to ionizing radiation carries with the possibility
of inducing a stochastic effect.
However, the severity of the damage is not related to the size of
the inducing dose.
56. Nonstochastic effects (deterministic effects)
Nonstochastic effects (deterministic effects) are somatic effects
that have a threshold and that increase in severity with
increasing absorbed dose.
Examples of nonstochastic effects include erythema, loss of hair,
cataract formation, and decreased fertility.
Compared with stochastic effects,deterministic effects require
larger radiation doses to cause serious impairment of health.
57.
58. Short-Term Effects
Following the latent period, effects that are seen within
minutes, days, or weeks are termed short-term effects.
Short-term effects are associated with large amounts of
radiation absorbed in a short time (e.g., exposure to a
nuclear accident or the atomic bomb).
Acute radiation syndrome (ARS) is a short-term effect
and includes nausea,vomiting, diarrhea, hair loss, and
hemorrhage.
59. Long-term effects
Effects that appear after years, decades, or generations
are termed long-term effects.
Long-term effects are associated with small amounts of
radiation absorbed repeatedly over a long period. Repeated
low levels of radiation exposure are linked to the induction of
cancer, birth abnormalities, and genetic defects.
60. Somatic and Genetic Effects
All the cells in the body can be classified as either somatic
or genetic.
Somatic cells are all the cells in the body except the
reproductive cells.
The reproductive cells (e.g., ova, sperm) are termed
genetic cells.
Depending on the type of cell injured by radiation, the
biologic effects of radiation can be classified as somatic or
genetic.
61. somatic effects
Somatic effects are seen in the person who has been irradiated.
Radiation injuries that produce changes in somatic cells produce
poor health in the irradiated individual.
Major somatic effects of radiation exposure include the
induction of cancer, leukemia, and cataracts.
These changes, however, are not transmitted to future
generations
62. Genetic effects
Genetic effects are not seen in the irradiated person but are
passed on to future generations. Radiation injuries that produce
changes in genetic cells do not affect the health of the exposed
individual.
Instead, the radiation-induced mutations affect the health of the
offspring .
Genetic damage cannot be repaired.
63. Doubling dose: dose of radiation expected to double the
number of genetic mutations in a generation.(or) Amount of
radiation that doubles the incidence of stochastic effects.
Human data from Hiroshima/Nagasaki
suggest somewhat average doubling dose is
1.6 Sv
64. Effects on the fetus
The developing fetus is particularly sensitive to the effects of
radiation, especially during the period of organogenesis (2–9
weeks after conception).
Exposures in the range of 2 to 3 Gy during the first few days
after conception are thought to cause undetectable death of the
embryo.
The period of maximal sensitivity of the brain is 8 to 15 weeks
after conception.
65. The major problems are:
1.Congenital abnormalities or death associated with large
doses of radiation
2.Mental retardation associated with low doses of radiation.
As a result, the maximum permissible dose to the abdomen of a
woman who is pregnant is regulated by law.
68. 1. Nature of tissue irradiated
2. Area irradiated:
3. Rate of dose
4. Fractionization:
5. Latent period:
6. Age of the patient:
7. Recovery power of the tissue
8. Type of cell:
9. Type of irradiation:
10. Stage of development of the tissue:
11. Tissue threshold:
12. Species and individuals:
13. Oxygenation:
Factors determine biological effects of
radiation
69. 1. NATURE OF TISSUE IRRADIATED.
i. Radioresponsive.
ii. Radioresistant.
2. AREA IRRADIATED:
For the same dose, if a smaller area is irradiated, the effect of radiation is
less.
3. RATE OF DOSE:
Smaller the dose, distributed over a large period of time results in a
smaller or lesser effect of the radiation.
70. CONT….
4. FRACTIONIZATION:
Division of the dose, with sufficient gaps, helps in
tissue recovery resulting in lesser effect of the
radiation.
5. LATENT PERIOD:
This is the period between the time of irradiation
and the appearance of the effect.
6. AGE OF THE PATIENT:
Younger the patient greater the chances of
recovery.
71. CONT….
7. RECOVERY POWER OF THE TISSUE:
Undifferentiated cells have a greater power of recovery.
8. TYPE OF CELL:
The effect of radiation is seen in the same generation if a somatic cell is effected,
and in case of the genetic cell the effect of radiation will be seen in the next generation.
9. TYPE OF IRRADIATION:
There are different types of irradiations—low energy, high energy or linear energy
transfer.
72. CONT…
11. TISSUE THRESHOLD:
Greater the tissue threshold,lesser the damage seen. This depends on the
amount of radiation absorbed. Somatic changes do not occur until a minimum
of tissue threshold is exceeded. Genetic changes occur with any given dose.
12. SPECIES AND INDIVIDUALS:
Different species respond differently. The median lethal dose varies in
different species. Similarly in individuals of the same species the response may
be variable. This variation of the Maximum Permissible Dose is approximately
50 percent
73. OXYGENATION:
Greater oxygenation of the tissue,chances of recovery are greater, e.g.
hyperbaric oxygen is used to treat osteoradio necrosis.
The presence of oxygen in a cell acts as a radiosensitizer making the effects of
the radiation more damaging. Tumor cells typically have a lower oxygen
content than normal tissue.
This condition is known as tumor hypoxia and therefore the oxygen effect acts
to decrease the sensitivity of tumor tissue. Generally it is believed that neutron
irradiation overcomes the effect of tumor hypoxia, although there are
counterarguments.
74. BIOLOGICAL EFFECTS
EFFECT ON CELLS
1.DNA
2.CYTOPLASM
3.NUCLEUS
4.CHROMOSOMES
5.PROTEINS
6.CELL DIVISION
7.CELL DEATH
RADIATION EFFECT ON CRITICAL ORGANS
1.SKIN
2.BONE MARROW
3.THYROID
4.GONADAL
5.EYE
EFFECT ON ORAL TISSUES
1.ORAL MUCOSA-MUCOSITIS
2.TASTE BUDS
3.SALVARY GLANDS-XEROSTOMIA
4.TEETH- RADIATION CARIES
5.BONES-OSTEORADIO NECROSIS
EFFECT ON WHOLE BODY
1.ACUTE RADIATION SYNDROME
2.HEMATOPOITIC SYNDROME3.
3.GASTROINTESTINAL SYNDROME
4.CARDIOVASCULAR SYNDROME
5.CENTRAL NERVOUS
75.
76.
77.
78.
79.
80. Single strand break can repair
Double strand break is responsible for
.mutation
.cell death
.carcinogenisis
Point mutations: Effect of radiation on individual genes is
referred to as point mutation.
81. Single strand break can repair
Double strand break is responsible for
.mutation
.cell death
.carcinogenisis
Point mutations: Effect of radiation on
individual genes is referred to as point
mutation.
82. CYTOPLASM
Increased permeability of plasma
membrane to sodium and potassium ions.
Swelling and disorganization of
mitochondria.
Focal cytoplasmic necrosis.
84. Denaturation
primary structure of the protein is usually not
significantly altered
secondary and tertiary structures are effected
by breakage of hydrogen or disulfide bonds
Inactivation of enzymes sometimes occurs.
PROTEINS
87. Chromosome Aberrations
If radiation exposure occurs after DNA synthesis (I,e G2 or late
s)only one arm of the effected chromosome is broken
If radiation occurs before DNA synthesis (G1 or early S) both arms
are effected
90. EFFECTS ON CELL REPLICATION
Mild dose-mild mitotic delay
Moderate dose-longer mitotic delay
Severe dose-profound delay with
incomplete recovery
91. CELL DEATH
Reproductive death in a cell population is loss of the capacity
for mitotic division. The three mechanisms of reproductive
death are
DNA damage,
Bystander effect
Apoptosis.
92. Bystander effect
It is the phenomenon in which unirradiated(normal)
cells exhibit irradiated effects as a result of signals
received from nearby irradiated cells.
This bystander effect has been demonstrated for both
α particles and x rays and causes chromosome
aberrations, cell killing, gene mutations, and
carcinogenesis.
93. APOPTOSIS
Leaves falling from tree
Also known as’ programmed cell death’
Apoptosis is particularly common in hemopoietic
and lymphoid tissues.
94. BIOLOGICAL EFFECTS
EFFECT ON CELLS
1.DNA
2.CYTOPLASM
3.NUCLEUS
4.CHROMOSOMES
5.PROTEINS
6.CELL DIVISION
7.CELL DEATH
RADIATION EFFECT ON CRITICAL ORGA
1.SKIN
2.BONE MARROW
3.THYROID
4.GONADAL
5.EYE
EFFECT ON ORAL TISSUES
1.ORAL MUCOSA-MUCOSITIS
2.TASTE BUDS
3.SALVARY GLANDS-XEROSTOMIA
4.TEETH- RADIATION CARIES
5.BONES-OSTEORADIO NECROSIS
EFFECT ON WHOLE BODY
1.ACUTE RADIATION SYNDROME
2.HEMATOPOITIC SYNDROME3.
3.GASTROINTESTINAL SYNDROME
95. RADIATION EFFECT ON
CRITICAL ORGANS
In radiography the critical organs receiving scattered radiation include:
SKIN
BONE MARROW
THYROID
GONADAL
EYE
96. Skin:
I. EARLY OR ACUTE
SIGNS:.
• Intolerance to surgical scrub.
• Blunting and leveling of finger
ridges.
• Brittleness and ridging of finger
nails.
.
97. ii. LATE OR CHRONIC
SIGNS:
• Loosening of hair and epilation.
• Dryness and atrophy of skin, due to
destruction of the sweat glands.
• Progressive pigmentation, telangiectasia
and keratosis.
• Indolent type of ulcerations.
• Possibility of malignant changes in tissue
98. All these changes in the skin are due to radiation
trauma to:
1-The blood vessels.
2- Connective tissue.
3- Epithelium.
Early erythema may appear from a single dose of
about 450 rads.
With lower doses no erythema occurs.
99. BONE MARROW
A maximum dose of 200 R is required for any damage to the
marrow or blood forming organs.
The primary somatic risk from radiography is leukemia
induction,especially in young individuals.
This is because at birth all bones contain only red bone marrow.
younger individuals are at a greater risk of developing
leukemia.
100. THYROID A dose of 10 R will produce thyroid cancer.
Eye Cataract of the lens is produced after 500 R of
exposure.
101. EFFECT ON WHOLE BODY
1.ACUTE RADIATION SYNDROME
2.HEMATOPOITIC SYNDROME3.
3.GASTROINTESTINAL SYNDROME
4.CARDIOVASCULAR SYNDROME
5.CENTRAL NERVOUS
BIOLOGICAL EFFECTS
EFFECT ON CELLS
1.DNA
2.CYTOPLASM
3.NUCLEUS
4.CHROMOSOMES
5.PROTEINS
6.CELL DIVISION
7.CELL DEATH
RADIATION EFFECT ON
CRITICAL ORGANS
1.SKIN
2.BONE MARROW
3.THYROID
4.GONADAL
5.EYE
EFFECT ON ORAL TISSUE
1.ORAL MUCOSA-MUCOSITIS
2.TASTE BUDS
3.SALVARY GLANDS-XEROSTOM
4.TEETH- RADIATION CARIES
5.BONES-OSTEORADIO NECROSI
103. Mucositis
Describes inflammation of oral mucosa resulting from
chemotherapeutic agents or ionizing radiation,Typically
manifests as erythema or ulcerations.
May be exacerbated by local factors.
Blood in the mouth
Sores in mouth,gums and tongue
104.
105. TASTE BUDS
These are sensitive to radiation and patient
realizes a loss of taste in the second or third
week of radiation therapy.
. It may take 2 or 3 months or more before your taste
sensations return.
It is common to have an increased sensitivity to sour and
bitter taste,or to have a “metallic” taste in your mouth
Changes in taste may cause you to lose your appetite.
106.
107. MANAGEMENT
Research has shown that taking zinc
sulfate during treatment may be
helpful in expediting the return of
taste after irradiation.
108. SALIVARY GLANDS
Parotid gland is more radio sensitive than the
other glands
Decrease salivary secretion(XEROSTOMIA)
fibrosis
loss of fine vasculature
and simultaneous parenchymal degeneration.
109. There is marked decrease in the salivary flow.
• The saliva loses its lubricating properties.
• The mouth becomes dry and tender due to xerostomia.
• The pH of saliva is decreased which may initiate
decalcification of enamel.
• A compensatory hypertrophy of the salivary gland may
take place and the xerostomia may subside after six to twelve
months after therapy.
110. Acute Radiation Syndrome (ARS) is an acute
illness caused by irradiation of the entire
body (or most of the body) by a high dose of
penetrating radiation in a very short period of
time (usually a matter of minutes)
ACUTE RADIATION SYNDROME
111.
112. stages of ARS
PRODROMAL STAGE (N-V-D STAGE): The classic symptoms for this stage are nausea,
vomiting, as well as anorexia and possibly diarrhea (depending on dose), which occur
from minutes to days following exposure. The symptoms may last (episodically) for
minutes up to several days.
LATENT STAGE: In this stage, the patient looks and feels generally healthy for a few
hours or even up to a few weeks.
MANIFEST ILLNESS STAGE: In this stage the symptoms depend on the specific
syndrome and last from hours up to several months.
RECOVERY OR DEATH: Most patients who do not recover will die within several
months of exposure. The recovery process lasts from several weeks up to two years
114. Bone marrow (hemopoietic)
syndrome:
(2 to7 Gy) Here severe damage may be caused to the circulatory system.
The bone marrow being radiosensitive, results in fall in the number of
granulocytes, platelets and erythrocytes.
Clinically this is manifested as lymphopenia, granulocytopenia and
hemorrhage due to thrombocytopenia and anemia due to depletion of the
erythrocytes.
115. Gastrointestinal syndrome
(7 to 15 Gy): This causes extensive damage to the
gastrointestinal tract, leading to anorexia, nausea,
vomiting,severe diarrhea and malaise.
116. Cardiovascular and central nervous
system
syndrome
(more than 50 Gy): This produces death within
one or two days. Individuals show
incordination,disorientation and convulsions
suggestive of extensive damage to the nervous
system.
118. As Low As Reasonably
Achieved
¨ Implies a balancing of benefit( risk
reduction ) vs cost (financial and
cost)
¨ 1.planning regarding protection in
advance of construction
¨ 2.utilizing all appropriate protective
measures
ALARA
119.
120. X ray intensity decreases
rapidly with distance from
source ;
conversely , intensity increases
rapidly with closer distance to
source
Inverse square law
121. 1. Distance between x-ray tube and
patient
2. Distance of patient to image
receptor
3. Collimation
4. Fluoroscopic and radiographic
acquisition mode
Factors affecting dose of
exposure
122. 5. Fluoroscopy time
6. Wedge filter
7. Magnification
8. Thickness and composition of
patient
9. X ray beam quality
10. Pulse rate and pulse width for
pulsed fluro
11. And scaterr grid
12. Angulation
123. n The best configuration during surgery is with
intensifier up and the xray tube down
n This reduces the exposure to team and lens by
3 or more times
n The surgeon should not stand on the xray tube
side , since they will receive scattered radiation
up to 4-8 mSv
X ray tube position
124. n Standing on the intensifier side
reduces the exposure received by
one tenth
n If the surgeon stands on the xray
tube side,thyroid exposure is 3-
4times higher
n The dose rates to torso from the xray
tube side are 0.53 mSv/min, where as
standing on the intensifier side it is
just 0.02 mSv/min
128. Grid is placed in front of the image detector
A grid reduces the effect of scatter
( degrading image contrast), but it also
attenuates the primary x-ray beam( both
scatter and primary hit grid strip )
Typically require a 2 times increase in
patient dose rate to compensate for
attenuation
Surface dose rates - grid
129. Small patients produce less scatter
For smaller patient and small
body parts adequate imaging may
obtained without grid
Consider removing grid for
patients < 20 kg
130.
131. Confines the xray beam to an area of
the user choice .
Beam limitation to the smallest
possible dimensions by a variable
beam limiting device
Collimation
132. Thicker tissue masses absorb more
radiation, thus much more radiation
must be needed for larger patients
Risk to skin is greater in larger patients
Needs 2 times more exposure for every 5
cm increase in thickness
Effect of patient size on
dose
133. Factor which increases the scattered
radiation to surgeons
The more we want to magnify the image the
higher the relative entrance has to be, which
increases the scattered radiation
Placing the pt. as close to the image
intensifier ,reduces the scattered radiation
Intensifier diameter
134. Which part of the body most
exposed?
In surgeons, its first the hands,
followed closely by eyes ,though
more distant but more sensitive.
The third being thyroid
Specific body exposure
135. Google's with 0.15 mm lead equivalent attenuate
radiographic beams by 70%
Thyroid collar decreases scattered radiation by 2.5 fold
0.5lead apron used during fluoroscopy attenuate 95% of
scattered radiation, vs 80% for the light weight apron
Hand and glove protection ranges from 60% - 64% with
52-58 kV.
136. Folding the lead apron decreases its
efficiency by 20%
Bismuth is more effective in
absorbing scatter radiation than lead
Lead aprons should not be used for
more than 5 years
137. Eye Protection
Eye glasses made of plastic, standard glass, photochromic
lenses, and lead-glass lenses reduced the amount of
radiation exposure to the user’s eyes by 0% to 97%,
depending on the x-ray tube potential.
A lead-acrylic face mask reduced the brain dose by 81%.
138. Face Protection
If the operator’s eyes are exposed to radiation, the brain, nose,
cheeks, and mouth also are exposed. Face masks may be used to
protect the entire face of personnel who are exposed to radiation,
most likely in the form of scatter radiation from patients
Face masks are normally made of acrylic that is impregnated with
lead, and the head piece can be adjusted to fit the user.
Manufacturers also offer antistatic spray and antifog cleaner to keep
the masks clear and comfortable.
139. Thyroid Protection
Because of the thyroid’s location fairly close to the skin and
likely within the trajectory of scatter radiation, it is susceptible
to radiation damage that can trigger negative effects
throughout the body.
If this influential organ is not already protected with a neck
shield attached a lead apron, then a thyroid collar should be
worn.
140. Hand Protection
Radio protective gloves could block 15% to 30% of scatter
radiation, but if gloved hands are in the beam’s path, a
fluoroscopy machine will automatically increase the kilovolts
(kV), raising the amount of radiation exposure to medical
personnel and the patient; in these cases, gloves could provide
a false sense of protection and negate their benefit.
141. Hand Protection
One study noted that certain types of radiation-
attenuating flexible gloves are prone to produce forward-
scatter and backscatter x-rays, thus reducing their
protective effectiveness. Therefore, they concluded that in
lieu of shielding, time and distance were the best options
personnel had to protect their hands during
interventional radiology and cardiology procedures.
142. Leg Protection
Although technologists’ hands may seem closer to the
radiation source during interventional procedures, their legs
and feet may receive an equal or higher amount of radiation.
One study showed that the mean radiation dose to operators’
legs was between 0.19 and 2.16 mSv per interventional
procedure, while the hands received between 0.04 and 1.25
mSv. This leg exposure dropped to approximately 0.02 mSv
when protection was used.
143.
144.
145. n Must be worn by persons operating
fluro equipment and medical
personnel required to be present
within 6 ft of the primary beam
during fluro procedures.
n Must be worn such that it is not
shielded by lead aprons or other
shields
n E.g. film badges,tld badges.etc.
Personal dorsimeters
146.
147. n Certain C-arms have a virtual patient anatomy feature
which helps to select appropriate dose, corresponding
to selected body area
n Selectable dose rate ,according to patient size
n Integrated lasers, help to correctly position the beam to
mark on the body
Technical contribution
148. n Pulse acquisition , use of pulsed
images and avoidance of
screening will dramatically reduce
radiation exposure
n Correct operating factors:
Low KVP/highmA- high patient
dose rates
High kVp/low mA- low dose rates
with reduced contrast
150. Collimation without radiation:
view last hold image and adjust
collimation with graphical overlay on
image
patient positioning without radiation:
position patient via graphical display
showing central beam location and
edges of field on LIH
NEW DEVELOPMENTS IN DOSE
REDUCTION
152. Radiation Protection
The ICRP set out 3 fundamental principles for an overall system
of radiation protection:
JUSTIFICATION,
DOSE LIMITATION, AND
OPTIMIZATION OF PROTECTION.
.
153. Justification refers to the necessity to do more good than harm when
deciding whether radiation use is necessary.
The ICRP established dose limitations for occupational radiation to
manage workers’ exposure via proper facility design and operation
planning.
Within the optimization of protection principle are 3 more tenets of
radiation protection: TIME, DISTANCE, AND SHIELDING
154. Protective Pads
A drape over or under a patient also can be helpful to reduce scatter
radiation. One such drape is the RADPAD, a lead-free, disposable
bismuth antimony shielding pad. This pad may be disposed of in the
regular trash because it does not contain lead or vinyl.
Although the RADPAD now is made with bismuth, it is still safe for
regular disposal and the drapes come in a variety of procedure-
specific designs.
155.
156. Ceiling Suspended or Mounted
Shielding Screens
Leaded shields can either be acrylic or glass panels that can be suspended from the
ceiling or portable on wheels. These shields absorb up to 90% of the scatter
radiation with the equivalent of 0.50 mm of lead within their plastic or glass.
Because of their effective absorbency, especially in protecting the eyes, shields
should be used in all fluoroscopy suites, even though they may seem like a
hindrance at times.
Thornton et al found that a ceiling-suspended shield eliminated all detectable
radiation at the eye level of a phantom operator during digital subtraction
angiography, besting the protection provided by lead glasses and scatter radiation-
shielding drapes used either alone or together.
157.
158. Fetal Dose Limits
The National Council on Radiation Protection and
Measurements (NCRP) recommends an occupational radiation
fetal dose limit of 5.0 mSv during an entire pregnancy (with a
daily limit of 0.025 mSv), and less than 0.5 mSv per month. The
ICRP recommends less than 1.0 mSv total fetal exposure
during an entire pregnancy. In general, these limits are
achievable with the proper precautions in place.
159. n Radiation hazard can be reduced
through a variety of ways including
n Proper positioning of x-ray tube
underneath the patient
n When in lateral view ,staying away
from the x-ray tube , keeping the
xray tube at a maximal distance to
the patient.
Summary
160. n Not overusing magnification
n Considering scattering radiation
during procedures
n Wearing protective clothing
n Maintaining distance from the
source
n Keeping hands away from and
out of the beam
161. REFERENCES:
1.Grainger & alisons DIAGNOSTIC RADIOLOGY
Volume 1, chapter 10, radiation protection and patient doses in
diagnostic radiology
2 The fundamentals of x-ray and radium physics
Chapter 23. protection in radiology- health physics
3.Indian journal of radiology and imaging .
4. internet .
162. Next seminar by
DR K.SURYAVARDHAN
PAEDIATRIC FRACTURES
AROUND ELBOW on 7-09-15