Radioactive isotope/substance emits the following radiations EXCEPT
Correct Answer: X-rays
Description: Ans. d (X-rays) (Ref. Harrison 18th/ ch. 223, 85)RADIOACTIVE EMMISION# ISOTOPES of atoms with uneven numbers of protons and/or neutrons are typically unstable; such isotopes discharge particles or energy to matter, a process that we define as radiation.# Isotope has same atomic number and different atomic mass numberQ# The main radiation types are -- Alpha particles- Beta particles- Gamma rays- Neutrons.ALPHA (a) RADIATION (He++/ Helium nuclei)# consists of heavy, positively charged particles containing two protons and two neutrons.# Alpha particles are usually emitted from isotopes with an atomic number of >82, such as: Q- uranium or- plutonium.# Least penetrating power Q (Fine obstacles such as cloth or human skin can usually stop them from penetrating into the body).# Due to their large size, alpha particles have limited penetrating power.# Highest ionization potentialQ# If they somehow are internalized, then alpha particles can cause significant cellular damage within their immediate proximity.Beta (b) radiation# consists of electrons, which are small, light, negatively charged particles (about 1/2000 the mass of a neutron orproton).# They can travel only a short finite distance in tissue, depending on their energy.# Exposure to beta particles is common in many radiation accidents.# 13II, released in nuclear plant accidents, is the best known member of this group.# Plastic layers and clothing can stop most beta particles, and their penetration is measured to be a few millimeters.# A large quantum of energy to the basal stratum of the skin can cause a bum that is similar to a thermal bum and istreated as such.# Pure b-emitters include:- Phosphorous-32- Strontium-89 (used in Rx of painful bone metastases in dose 8Gy single fraction).- Yttrium-90- Samarium-153 (b + g)- Rhenium (b + g)Neutrons Particles# are heavy and uncharged, often emitted during nuclear detonation.# They possess a wide energy range; their ability to penetrate tissues is variable.Points of differencex-raysy-raysOriginExtranuclearIntranuclearProduced by- x-ray tube - Linear accelerator0Radioactive isotopes like Co-60, Tc99mPenetrating powerIntermediateHighestIonization potentialIntermediateLeastDiagnostic use- Radiography- Mammography- Contrast radiography (IVU, Ba studies, DSA, etc)- Xeroradiography (Outdated)- Fluoroscopy- CT scan - DEXANuclear scan (Scintigraphy/Gamma-imaging) Therapeutic useTeletherapy (Ortho < Super < Megavoltage x-ray therapy). * Megavoltage X-ray therapy causes no skin damage.Tele as well as brachytherapy
Category:
Radiology
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