The document discusses the biological effects of radiation and principles of radiation protection. It describes how radiation can cause structural changes in DNA through processes like hydrogen bond breaking, molecular breakage, and cross-linking. The harmful effects are categorized as deterministic, which increase in severity with dose, and stochastic, where probability but not severity increases with dose. Examples of acute radiation syndrome are provided. Radiation risk includes somatic, genetic and fetal risk. Radiation protection aims to prevent deterministic effects and limit stochastic effects through justification of practices, optimization of protection and setting dose limits. Methods to minimize exposure include reducing time spent in radiation fields, increasing distance from sources, and using shielding materials.
Effects of radiation
Signs and symptoms of radiation
Infected period of radiation
Dosage
Calculation of dosage
Units and SI units used
Diseases caused by radiation
Radioresistant
Effects of radiation
Signs and symptoms of radiation
Infected period of radiation
Dosage
Calculation of dosage
Units and SI units used
Diseases caused by radiation
Radioresistant
Biological effects of radiation provides the knowledge about how the radiation effects human beings and animals and how can we saves ourself from radiation.
This power-point presentation is very important for radiology resident radiologist and radiographers and technician. this includes principles, technique , biological effects of radiation and how to protect, whats should normal radiation dose with latest update. This slide also includes ALARA PRINCIPLE thanks.
Biological effects of radiation provides the knowledge about how the radiation effects human beings and animals and how can we saves ourself from radiation.
This power-point presentation is very important for radiology resident radiologist and radiographers and technician. this includes principles, technique , biological effects of radiation and how to protect, whats should normal radiation dose with latest update. This slide also includes ALARA PRINCIPLE thanks.
Acute radiation syndrome (ARS) or acute radiation sickness is an acute illness caused by irradiation of the entire body (or most of the body) by a high dose penetrating radiation in a very short period of time (usually a matter of minutes). The major cause of this syndrome is depletion of immature parenchymal stem cells in specific tissues.
Classically, acute radiation syndrome is subdivided into three sub-syndromes:
the hematopoietic syndrome,
the gastrointestinal syndrome,
the cerebrovascular syndrome
others include :
pulmonary syndrome, cutaneous radiation injury
radiation-induced multi organ dysfunction (failure) syndrome.
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
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
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
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
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.
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
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.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
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.
2. BIOLOGICAL EFFECTS OF RADIATION
• Radiation can cause cause biological damages
on either by direct & indirect action
• If radiation falls on human body, it produces
moving electrons.
• These electrons causes ionization , excitation
resulting in chemical and molecular changes.
• Radiation can also produce free radicals,
which are unpaired electrons that are
chemically reactive.
3. • Ex: radiation can interact with water molecule
and produce hydroxyl (OH) and hydrogen(H)
radicals.
• These free radicals interact with DNA,RNA or
PROTEIN molecule and cause damage tissue.
• Chromosomal breaks and aberrations are
examples of biological damage caused by
radiation.
• Scoring of human lymphocytes is used as
biological dosimeter
4.
5. • Radiation induce structural changes in a DNA
molecule
• 1) hydrogen bond break
• 2)molecular breakage
• 3)inter and intramolecular cross linking
6. • Hydrogen bond break disturbs the base pairs
such as adenine-thymine resulting in genetic
changes.
• Molecular breakage may involve single strand
break and double strand breaks.
• Single strand breaks are mostly repairable.
• Double strand breaks are irreparable and
cause loss of base or change of base called
mutation, leading to carcinogenesis
7. • High dose of radiation can cause
• 1) cell death (deterministic effect)
• 2) cellular transformation (stochastic effect)
• Lymphoid tissue and rapidly proliferating tissues
(spermatids & bone marrow stem cells) are
relatively radiosensitive
• Nerve cells are least radiosensitive
8. • An acute dose delivered in a short time is
more harmful than a chronic dose delivered
over a period of time
• The radiation effects which manifest soon
after radiation are called early effects
• Those effects that manifest after a short
period of time are called late effects.
9. • The harmful effects of radiation are
• 1) deterministic effects
• 2) stochastic effects
10. DETERMINISTIC EFFECTS
• In this effect “ severity increases with
increasing absorbed dose”
• These effects appear at high doses > 0.5 Gy
and generally result from cell death
• These effects are characterized by threshold
dose, below which the effect does not occur
• These include skin erythema, epilation, organ
atrophy, fibrosis, cataract induction, blood
changes and reduction in sperm count.
11.
12. Stochastic effect
• In this effect,” the probability of occurrence
increases with increasing absorbed dose rather
than its severity”
• Classified in to somatic and genetic effects
• Severity of stochastic effect is independent of
radiation dose
• It has no threshold dose, may occur even at low
doses
• Radiation induced cancer and hereditary effects
come under this category
13.
14. ACUTE RADIATION SYNDROME
• Whole body radiation exposures involving
high level radiations delivered in shorter
interval can cause acute radiation syndromes
• It includes
• 1) haemotopoietic syndrome
• 2) gastrointestinal syndrome
• 3) cerebrovascular syndrome
15. LAW OF RADIOLOGY/ LAW OF
TRIGONIE AND TRIBONDEAU
Tells about radiosensitive and radioresistant tissues
Radiosensitive tissues: tissues which have
maximum number of undifferentiated cells/cells
in active mitosis
ex bone marrow ( acute haematological syndrome)
GI mucosal cells (acute GIT syndrome)
Acute CNS/CVS is the last syndrome which occurs
because CNS cells are radioresistant
16. • clinical stages of acute radiation syndrome
• Stage1/prodromal stage-nausea,vomiting,diarrhoea.
few minutes to hours
• Stage2/latent stage: few hours to days
• Stage3/manifest illness stage: few days to weeks
• Stage4/recovery/death stage: few weeks to years
17. • ACUTE HAEMATOLOGICAL SYNDROME
• Threshold dose: 1-2 Gy
• Results in pancytopenia
• Recurrent infections and recurrent
haemorrhages are the cause of death in these
pts
18. • ACUTE GIT SYNDROME
• Threshold dose: 6-10 Gy
• Radiation enteritis (mucosal layer is shed off)
usually presents as diarrhoea
• Other symptoms: malaise, severe diarrhoea,
electrolyte imbalance
19. • ACUTE CNS/CVS SYNDROME
• Threshold dose: 20 GY
• Death usually occurs due to circulatory
collapse or raised ICT
20. • Doses > 100 Gy may cause death in 24-48 hrs-
cerebrovascular syndrome.
• Dose 5-12 Gy may cause death in days -
gastrointestinal syndrome.
• Dose 2.5-5 Gy may cause death in weeks to
months -haematopoietic syndrome.
• The dose that causes 50% death over a specified
time (60 days) is called lethal dose and is
expressed in LD50/60, which is about 4 Gy for
humans
21. ALARA PRINCIPLE
• It is the principle which deals with radiation
safety
• It is followed when ever there is requirement
of radiation exposure to the pt i.e, as low as
reasonably achievable
• And not very low because image quality would
be compromised which results in misdiagnosis
22. • In reproductive age group, All x-ray based
investigations should be done in the first 10
days of the menstrual cycle
• Ideal time for HSG: 6th to 10th day
Injection of contrast is avoided in the first 5-6
days to prevent the risk of infections
23. • CLASSIFICATION OF RADIATION EXPOSURE IN VARIOUS
MODALITIES
• 1.Green zone/safe zone/spot radiographs
• Pt exposed to radiation once(chest x ray) or twice(x ray
wrist)
• 2.yellow zone/warning zone/diagnostic procedures
• pt exposed to radiation multiple times(IVU,MCUG)
• 3.red zone/danger modalities
• Radiation exposure very high (CT
HEAD/THORAX/ABDOMEN), PET scan, bone scan
24. ICRP/ICRU GUIDE LINES
• ICRP: international commission on radiology
protection
• ICRU: internation commission on radiation units
• Public exposure: effective dose 1msv/year
• annual equivalent dose to lens of eye 15 msv
• Annual euivalent dose to skin 50 msv
• For pregnant and radiation workers- should not
to exceed 1msv
25. • Occupation exposure
• Effective dose over all 20msv/yr..(< 100 msv in
5 yrs)
• Annual equivalent dose to lens of eye 150 msv
• Annual equivalent dose to skin 500 msv
26. RADIATION RISK
• When exposed to radiation, the expected risk
includes
• 1) somatic risk
• 2) genetic risk
• 3) fetal risk
27. Somatic risk
• The radiation effects, produced in an
individual during his life time are called
somatic effect
• Cancer induction is the largest risk
• Bone marrow, gastrointestinal mucosa, breast
tissue and lymphatic tissue are most
susceptible to radiation induced malignancy
• Cancer risks are generally higher for children
than for adults
28. Genetic risk
• The radiation effects produced in the
successive generation of the exposed
individual are called genetic effects
• These effects are the result of radiation
exposure to the gonads
• There is no epidemiological evidence of
genetic effect in humans
• The current ICRP risk estimate for hereditary
effects is 0.1% per Sv
29. Fetal risk/pregnancy
• The effects of radiation on embryo and fetus are
• 1) lethal effects
• 2)malformations
• 3)growth disturbances
• The developmental period in utero has three
stages namely 1)preimplantation
• 2)orgnogenesis
• 3)fetal period
30. • Preimplantation is the most sensitive stage,
which causes lethal effects.
• The fetal risk depends on the gestation period of
the pregnant women
• Mothers exposed to diagnostic x-rays in the third
trimester, resulted in excess childhood leukemia
• Diagnostic x-rays can increase the risk of
chidhood cancer by 40%
• To avoid radiation induced congenital anomalies,
an abortion may be advised only when dose
exceed 100 mGy
31. RADIATION PROTECTION
• The aim of radiation protection is to prevent
deterministic effects and limit the probability
of stochastic effects
• These could be achieved by
• 1) setting limits well below threshold dose
• 2)limiting exposures as low as reasonably
achievable (ALARA)
32. • The whole radiation protection summarized as
• 1) justification of practice: no radiation exposures
shall be adopted unless it produces a net positive
benefit
• 2)optimization: every effort shall be taken to
reduce the dose as low as reasonably achievable
• 3)dose limits:the effective doses to the
individuals shall not exceed the limits
recommended by the commission
33. • Pregnant radiation workers are monitored by
a dosimeter worn on the abdomen under the
lead apron
• A measured dose of 2 mSv to the surface of
the abdomen is normally considered
equivalent to 1 mSv to the fetus
• The dose limits for members of the public are
generally 10 times lower than those for
occupation exposure
34. • The three principal methods by which
radiation exposures to persons can be minized
are
• 1) time
• 2) distance
• 3) shielding
35. Time
• The total dose received is directly proportional
to the total time spent in handling the
radiation source
• Techniques to minimize time in a radiation
field should be recognized or practiced.
• Nuclear medicine procedure produces lower
exposure rate for extended period of time
36. Distance
• Radiation intensity (exposure rate) from a
point source decreases with distance due to
divergence of a beam
• Exposure rate from a point source of radiation
is inversely proportional to the square of the
distance.( inverse square law)
• If the exposure rate is X1 at distance d1, then
the exposure rate at another distance d2 is
given by X2 = X1(d1/d2)2
37. • In diagnostic radiology at 1m from a patient,
the scattered radiation is about 0.1-0.15% of
the intensity of primary beam
• Personnel should be atleast 2m from the x ray
tube and behind shielded barrier or out of
room
• Imaging rooms should be designed to
maximize the distance between the source
and control console
38. shielding
• The material that attenuates the radiation
exponentially is called shield
• The shield will reduce the exposure to patients,
staff and public
• Larger the shielding thickness, lesser the
radiation exposure
• The thickness of the shielding material that
reduces the intensity to half is called half value
thickness(HVT) and is given by relation
HVT= 0.693/mu
39. • Optimal shielding is required to bring down
the radiation level below he permissable limit.
• Brick, concrete are used as shielding material
for construction of x-ray room barriers
• Lead is used as protective material in lead
apron, thyroid shield and gonad shield
40. • The calculation of barrier shielding require the
understanding of five factors
1)Workload
2)Use factor
3)Occupancy factor
4)Distance
5)Radiation exposure level
41. • GOOD WORK PRACTICES IN DIAGNOSTIC
RADIOLOGY
• 1)X-RAY EXAMINATION
• X-ray examination should be prescribed only
after critical evaluation of patients condition
in order to avoid unnecessary exposures
• No fluoroscopic examinations should be
conducted , if the required information can be
obtained by radiography
42. • 2) QUALITY ASSURANCE
• Every new x-ray unit shall be subjected to to
quality assurance tests before patient use
• Only qualified x-ray tecnologists will be
allowed to handle x-ray equipment
43. • 3) EQUIPMENT OPERATION
• Personnel monitoring devices shall be used by
all radiation workers while on duty
• Before making an exposure, the doors of the
x-ray room must be closed
• While performing portable examinations, the
operator should stand atleast 2m away from
the pt
44. 4)PROTECTIVE SHIELD
- All radiation workers must wear lead apron of
0.5 mm thickness, which reduces radiation
exposure by a factor of 10
-use of leaded glasses, lead gloves must be
encoraged in fluoroscopy type of work
-thyroid shield, gonad shield,eye shields
should be used to protect the patient during
radiography
45. • 5)FIELD AREA
• Minimal field size to cover the pt volume
shoulf be used
• Field size reduction reduces the scatter
thereby reducing the dose to adjacent organs
• The scatter incident on the detector also
decreases, resulting in improved image
contrast
46. • 6)SOURCE TO OBJECT DISTANCE
• Higher the source to object distance(SOD) and
source to image distance(SID),lesser the
patient dose
• Increase of SOD/SID, reduces beam
divergence , in turn reduces the volume of
patients irradiation
47. • In radiography and fluoroscopy with
stationary X-ray equipment, the SOD should
be not less than 45cm
• Chest radiography should be performed with a
SID of atleast 120cm
• in flouroscopy, the minimum distance
between source and the patient must be not
less than 30cm
48. • 7)OCCUPANCY IN THE ROOM
• Only persons whose presence is necessary
should be in the imaging room during
exposure
• All such persons must be protected with lead
aprons/shields
• The x-ray room should be kept closed during
radiation exposure
49. • 8) ASSISTANCE TO PATIENTS
• Holding of children or infirm patients for X-ray
examination shall be done only by adult
relative of the patient
• Hospital personnel should not hold patients
during imaging procedure
50. • 9)PREGNANT WOMEN
• radiological examination of the lower abdomen and pelvis
of a pregnant women must be conducted only when
considered absolutely essential
• 10)LOG BOOK
• Each X-ray equipment must have a separate log book,
which provides information about the equipment
manufacturer, model, serial number, date of purchase
• 11)RECORDS
• Records of all radiological examination must be maintained
51. SUMMARY
• BIOLOGICAL EFFECTS OF RADIATION
• Radiation induce structural changes in DNA molecule 1)
hydrogen bond break, 2) molecular breakage, 3) inter
and intramolecular cross linking
• The harmful effects of radiation 1)deterministic effects
& 2)stochastic effects
• Acute radiation syndrome includes 1)haematopoietic
syndrome, 2)gastrointestinal syndrome,
3)cerebrovascular syndrome
52. • Radiation risk- 1)somatic risk 2)genetic risk 3)fetal risk
• RADIATION PROTECTION
• Whole radiation protection summarized as
1)justification of practice 2)optimization 3)dose limits
• The three principal methods by which radiation
exposure can be minimized 1)time 2)distance
3)shielding