MEDRADSC 3G03 Lecture Notes - Lecture 17: Field Of View, Biopsy, Dynamic Range

• School: McMaster University
• Department: Medical Radiation Sciences
• Course: MEDRADSC 3G03
• Professor: Dwight Mountford

Document Summary

Mammography- x-ray tube: cathode - standard helical-shaped tungsten filament in a focusing cup, dual filaments, geometric blurring and maintains spatial resolution. Mammography- filters: mammography filters are made of the same elements as the anode material, mo = 0. 03mm mo, can"t do mo filter with rh anode, rh = 0. 025mm rh. Low absorbing back cover aec: no chance of back scatter- should absorb as much remnant beam as possible. Intensifying screens patient dose: when the x-rays hit it, it lights up, made up of high ato(cid:373)i(cid:272) (cid:374)u(cid:373)(cid:271)ers, the light does(cid:374)"t ha(cid:448)e a (cid:272)ha(cid:374)(cid:272)e to spread sharper image (pic- look up in textbook, proper loading of film. Limitations of film-screen detectors: need to achieve high radiographic contrast. Large area detector using fiber optic taper ccd cameras: cr, flat panel detectors using tfts, direct vs indirect plate: direct (photons digital data) (photons light digital data) Advantages of digital mammography (pic: overcome limitations of film-screen systems.