MCQ ON GAMMA IMAGING

589.True regarding isomeric transition

a.⁹⁹Mo decays by the emission of beta particle with 

simultaneous emission of gamma rays

b.⁹⁹T_c^mm decay to the ⁹⁹T_c with emission of Gamma ray of 

energy of 140 keV

c. ⁹⁹T_c has short half-life

d.Decay of rubidium-81 to krypton -81 is an example of 

isomeric transition

e.isomers have different energy states and half-life

ANS OF PREVIOUS BLOG

569.True regarding beam hardening artefact

a.there is hardening of x ray beam as it crosses the patients

 due to filtering of low energy photons

b.attenuation coefficient and the CT number of a given 

tissues increase along the beam path

c.CT numbers are lower in the periphery of the patients 

(inverse cupping)

d.may produce dark streaks in the image

e.may be reduced by beam hardening artefact and bow-tie

 filter

569.ade-----Due to  beam hardening artefact ,attenuation coefficient and the CT number of a given tissues decrease  along the beam path and so CT numbers are lower in the centre  of the patients (cupping).(Chapter 7, page no.115,second edition (2008),Farr’s Physics for Medical Imaging).