Low-energy imaging with high-energy bremsstrahlung beams

Journal Article · Fri Sep 01 04:00:00 EDT 1989 · Medical Physics; (USA)

DOI:https://doi.org/10.1118/1.596332· OSTI ID:5130487

Galbraith, D M ^[1]

---

1. Ontario Cancer Institute, Toronto (Canada)

A method is described for portal imaging with low-energy (approximately less than 150 keV) photons from a radiotherapy accelerator operating in a diagnostic mode. The low-energy photons are produced in the bremsstrahlung process, but are normally filtered out by thick high atomic number (Z) target materials. This absorption can be reduced by choosing a low Z target with the minimum thickness required to stop the electrons in the target. If, in addition, the operating energy is kept low (approximately 5 MeV) and the flattening filter is removed, low-energy photon images can be produced from the broad spectrum of photon energies by using standard diagnostic radiology high-Z fluorescent screen/film systems that strongly absorb at low but not high photon energies. Motion artifacts can then be avoided since only a small dose is required for such a procedure.

• OSTI ID: 5130487
• Journal Information: Medical Physics; (USA), Journal Name: Medical Physics; (USA) Vol. 16:5; ISSN 0094-2405; ISSN MPHYA
• Country of Publication: United States
• Language: English

Related Subjects

550602* -- Medicine-- External Radiation in Diagnostics-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
BIOMEDICAL RADIOGRAPHY
BREMSSTRAHLUNG
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FLUORESCENCE
LUMINESCENCE
MASSLESS PARTICLES
MEDICINE
NUCLEAR MEDICINE
PHOTONS
RADIATIONS
RADIOLOGY