M8L1 & L2- mobile radiograhy and bone densitometry

what is the battery in mobile radiographs made out of

lead or nickel cadmium

what ist he kvp and mas in high frequncy mobile units

133 kvp and 200 mas

what is unique abotu the high frequency mobile units

microprocessor circuit increase frequency of the AC to create. nerayl constant potential

bone densitometry

mesuring of bone mineral content and dennsity of the skeletal system

DXA stand for

dual energy xray absorptionmetry

what is DXA

scanning parts using 2 different photon energies to distinguish bone and soft tissue. soft tissue is subtracted from bone and is used to calculate the density of the bone

what are the 2 ways to achieve dual beam energies

k-edge filtered and energy switching system

what is k-edge diltered

primary beam passes through the filters causing the second beam to have a different energy

what is energy switchign system

kVp switching from 100 and 140. Primary beam will have 2 different energies. the peaks are at 40 and 80 kEv

what are common sites to scan for a DXA

femur, hip, spine, and forearm

what are disadvantages of DXA

beam hardeninng and scintillating detector pileup in k-edge filteration system. cross over in k-edge filteration systems

what is beam hardening

thicker body parts absorb lower enrgy photons and high energy photons are left

what does it mean by scintillating detector pileup in k-edge filteration systems

the detector can only process one photon at a time thus others can be missed when the first isnt processed. generally seen in digital detectors

what does it mean by crossover in k-edge filteration systems?

high energy photons are absorbed by the body and thus is read as low energy

is the dose of DXA high or low

low

when doing a DXA system with a array beam multiple detector/fan beam, where is the x-ray tube

below the table

what allows true obejct location to be calculated

Multiview image reconstruction

how is the fan beam system positioned

parallel to long axis of patient and scans inn tranverse pattern across the body