X-ray beam restrictors regulate the size and shape of the x-ray beam. There are three main types: aperture diaphragms, cones/cylinders, and collimators. Aperture diaphragms are the simplest type, using a lead diaphragm with a hole to shape the beam but producing a large penumbra. Cones and cylinders modify the aperture diaphragm design to restrict the beam size. Collimators provide adjustable rectangular fields using shutters and illuminated light beams to define the x-ray field size. Beam restrictors aim to decrease off-focus radiation, reduce the irradiated patient volume, and provide patient protection by limiting the x-ray field size
Collimators: Control the size and shape of the X-ray beam by limiting devicessudheendrapv
Collimators: Control the size and shape of the X-ray beam by limiting its aperture.
Aperture diaphragms: Restrict the size of the X-ray beam by blocking unwanted radiation.
Beam filters: Remove low-energy X-rays from the beam, reducing patient dose and improving image quality.
Gonad shields: Protect reproductive organs from unnecessary radiation exposure during X-ray procedures.
Grids: Improve image quality by reducing scatter radiation.
Positioning devices: Assist in accurately positioning patients, minimizing retakes and radiation exposure.
Lead aprons and barriers: Shield healthcare providers and patients from harmful radiation.
Compression devices: Compress body parts to reduce scatter radiation and enhance image quality.
Beam alignment devices: Ensure that the X-ray beam is properly aligned with the patient's anatomy.
Automatic exposure control (AEC) devices: Automatically adjust X-ray exposure according to patient size and anatomy for optimal image quality and dose optimization.
Collimators: Control the size and shape of the X-ray beam by limiting devicessudheendrapv
Collimators: Control the size and shape of the X-ray beam by limiting its aperture.
Aperture diaphragms: Restrict the size of the X-ray beam by blocking unwanted radiation.
Beam filters: Remove low-energy X-rays from the beam, reducing patient dose and improving image quality.
Gonad shields: Protect reproductive organs from unnecessary radiation exposure during X-ray procedures.
Grids: Improve image quality by reducing scatter radiation.
Positioning devices: Assist in accurately positioning patients, minimizing retakes and radiation exposure.
Lead aprons and barriers: Shield healthcare providers and patients from harmful radiation.
Compression devices: Compress body parts to reduce scatter radiation and enhance image quality.
Beam alignment devices: Ensure that the X-ray beam is properly aligned with the patient's anatomy.
Automatic exposure control (AEC) devices: Automatically adjust X-ray exposure according to patient size and anatomy for optimal image quality and dose optimization.
Radionuclide's such as radium-226, cesium-137, and cobalt-60 have been used as sources of gamma rays for teletherapy. These gamma rays are emitted from the radionuclide's as they undergo radioactive disintegration. Of all the radionuclide's, Co-60 has proved to be the most suitable for external beam radiotherapy.
IT REVIEWS Introduction and definition INTRODUCTION
BEAM-RESTRICTING DEVICES
ADVANTAGES AND DISADVANTAGES
TECHNIQUE
FILTERS
AND PHYSICS BEHIND IT AND LIGHT AND MIRROR ARRANGMENT CLEARLY EXPLAINED WELL.IT ALSO INCLUES THE FLITERS CLASSIFICATION AND COLLIMATORS CLASSIFICATION.
COLLIMATIORS ARE NOTHING BUT BEAM ALINERS
An X-Ray machine consists of two main components – X-Ray generator and an image detection system. An X-Ray tube essentially is a high-vacuum diode consisting of a Cathode and Anode. X-ray tube operates by generating a stream of electrons by heating up a cathode (tungsten) filament.An X-Ray machine consists of two main components – X-Ray generator and an image detection system. An X-Ray tube essentially is a high-vacuum diode consisting of a Cathode and Anode. X-ray tube operates by generating a stream of electrons by heating up a cathode (tungsten) filament.The positively charged anode is the target of electrons released from the cathode. Most of the electrons that strike the anode deposit their kinetic energy, generated by the applied tube voltage and current, as heat. Only a small fraction go on to produce X-rays. As a result, a significant amount of heat is generated at the anode in the production of diagnostic images. Stationary anodes were used in the past. However, the small focal spot on a stationary anode limits the number of X-rays that can be produced without damaging the anode. Therefore, most X-ray machines today use a rotating anode. This allows for the spread of heat over a larger area, which allows for greater tube currents and exposure durations. The rotating anode is a disk mounted on a bearing supported rotor assembly. The rotor consists of a center iron cylinder with surrounding copper bars. The stator device is made of electromagnets that surround the rotor. When an alternating current passes through the electromagnets of the stator, it produces a rotating magnetic field. This field produces an electrical current in the rotor's copper bars, which, in turn, creates an opposing magnetic field to the one induced by the stator—the results in the rotation of the rotor device. Rotation speeds of up to 10,000 revolutions per minute can be produced.The cathode, anode, rotor apparatus, and the other associated structures are collectively called the X-ray tube insert. They are all contained in a glass or metal enclosure and sealed under a high vacuum. This enclosure is known as the envelope. X-ray photons emitted from the focal spot scatter in all directions. The use of a tube port helps form a useful beam.
The X-ray tube housing provides shielding and cooling of the X-ray tube insert. Typically, between the insert and the housing is a layer of oil that provides heat conduction and electrical insulation. A lead shield is also applied to the inside of the housing to attenuate X-rays that are not directed to the tube port. However, not all X-rays are blocked, and the fraction that penetrates the housing is known as leakage radiation. Each tube housing has a maximum tube potential that should not be exceeded during operation at the risk of an unacceptable amount of leakage radiation. As the X-rays come out of the tube port, the size and shape of the X-ray field can be adjusted by collimators. The collimator housing attaches to the tube p
COMPARATIVE STUDY OF PARABOLIC TROUGH CONCENTRATORS IAEME Publication
In the present work two parabolic trough concentrator system of different rim angle and
different reflector aperture area is designed, fabricated, and evaluated, and operated for generate hot
water .There one system is 45° rim angle and next is of 90° rim angles, here reflector aperture area of
45° rim angle has operatically 20% more than 90° rim angle system, but remaining all other features
are same for both the 90° and 45° system. On operation of the system we gets nearly same efficiency
for both the system thus we observe that for all same equal features except of reflector aperture area,
the efficiency got 20+% more for 90° rim angle compare to 45° rim angle.
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.
Follow us on: Pinterest
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
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.
- 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
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
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.
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.
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.
HOT NEW PRODUCT! BIG SALES FAST SHIPPING NOW FROM CHINA!! EU KU DB BK substit...GL Anaacs
Contact us if you are interested:
Email / Skype : kefaya1771@gmail.com
Threema: PXHY5PDH
New BATCH Ku !!! MUCH IN DEMAND FAST SALE EVERY BATCH HAPPY GOOD EFFECT BIG BATCH !
Contact me on Threema or skype to start big business!!
Hot-sale products:
NEW HOT EUTYLONE WHITE CRYSTAL!!
5cl-adba precursor (semi finished )
5cl-adba raw materials
ADBB precursor (semi finished )
ADBB raw materials
APVP powder
5fadb/4f-adb
Jwh018 / Jwh210
Eutylone crystal
Protonitazene (hydrochloride) CAS: 119276-01-6
Flubrotizolam CAS: 57801-95-3
Metonitazene CAS: 14680-51-4
Payment terms: Western Union,MoneyGram,Bitcoin or USDT.
Deliver Time: Usually 7-15days
Shipping method: FedEx, TNT, DHL,UPS etc.Our deliveries are 100% safe, fast, reliable and discreet.
Samples will be sent for your evaluation!If you are interested in, please contact me, let's talk details.
We specializes in exporting high quality Research chemical, medical intermediate, Pharmaceutical chemicals and so on. Products are exported to USA, Canada, France, Korea, Japan,Russia, Southeast Asia and other countries.
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
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
2. X-RAY BEAM RESTRICTORS
• An x-ray beam restrictor is a device that is attached to
the opening in the x-ray tube housing to regulate the size
and shape of an x-ray beam.
• Basically,there are three types of beam restrictor
devices;
1.Aperature diaphragm
2.Cones and cylinders
3.Collimators
3. Aperature diaphragm
• Simplest type of X-ray beam restrictor attached to the x-
ray tube head.
• It is basicalllly lead or lead lined metal diaphagm with a
hole in the center,the size and shape of the hole determine
the size and shape of the x-ray beam.
• Principal advantage- simplicity, but produces large
penumbra.
• Lead closed to focal spot.
• Fixed image receptor size ,Constant SID.
• The width of the penbra can be reduced by positioning
the appratur diaphragm as far away from the x-ray
target as possible .
• Usually possible by attaching the diaphragm to the end
of a cone
4.
5. Cones and cylinder
❖Are the modification of aperture
diaphragm.
❖In both an extend metal structure
restricts the useful beam to the required
size.
❖Most commonly used type is cylinder.
❖Difficulty with using cone is
alignment.(cone cutting).
❖The flated shape of the cone would
seem to be ideal geometric
configuration for an x-ray
beamrestrictor but flared of cone is
greater the flared of x-ray beam.
7. Collimators
◆Collimators adjust the size and shape of the x-ray field
emerging from the tube port.
◆Collimators assembly typically attached to the tube
housing at the tube port with swivel joint.
◆It has two advantage's over other types:
◆Has two sets of shutters i.e longittudinal and trnsverse.
◆Sets may actually have two pairs of shutters operating
together.
◆The shutters functions as to adjustable Aprature
diaphragm
✓ provide adjustable rectangular field.
✓ Light beam indicate x-ray field.
10. ◆X-ray fields is illuminated by light beam from the bulb in
the collimator,which is deflected by a mirror mounted in
the path of the X ray beam at an angle of 45°.
◆The target of the X ray tube and bulb should be exactly
the same distance from the center of the mirror.
◆Have back up system for identifying field size in case the
bulb should burn out. Indicated by a calibrated scale on
the front of the collimator.
◆ Today,positive beam limiting (automatic collimator) are
used,which are same as other collimators except that
their shutters are motor driven.
11. ◆When casstes is loaded in to the Bucky sensor in the tray
sense the cassette size and alignment. Which relay
information to the collimator toanupulates the x ray field
size.
12. ◆Senses the film size , orientation
&SID.
◆ Limits x-ray field to size of the
film.But it doesn't insure tube
&bucket are aligned.
◆PBL must be accurate to with in 2%
of the SID
◆Light field and x-ray field aligned so
that the sum of the
misalignment,along either the
length or width of the field,with in
2%of the SID.
13. Testing X-ray Beam and Light beam
◆The alignment of the x-ray beam and light beam
should be checked periodically.
◆Equipment;
◆Make an exposurey to mark the position of the X-ray
field on the film(40 in.,3.3mAS, 40kVp).
◆ Then, enlarge the field size to 12×12in. and expose the
film again as same exposure.
● 4L shaped wires
● X-RAY film with cassette
● Small lead letter R
15. Functions Of Restrictors
◆Collimators and others x-ray beam restrictors two basic
functions.
○ Decrease off focus radiation.
○ Smaller the x-ray field ,smaller the volume of the
patient that is irradiated.
○ Patient protection is principal reason for using
collimator.
✓ Patient protection
✓ Decrease scatter radiation
16. Transmitted photon
Field size (cm²)
Figure; Transmitted radiation for various sizes of x-ray field
Transmittedphoton(Arbitrary
Units)
