Magnification survey and spot view mammography with a new microfocus X-ray unit: detail resolution and radiation exposure.
The aim of our study was to evaluate a mammography unit capable of magnification of up to fourfold at an equivalent or lower dose than with current systems. A prototype mammography tube with an electron-beam-focusing technology resulting in a focal spot size of 40-120 micro m was combined with a highly intensifying screen-film system. To evaluate contrast-detail resolution, phantom radiographs were performed with the prototype magnification mammography system using a magnification factor of 1.7 for survey views and a magnification factor of 4.0 for spot views. They were compared with unmagnified survey views and magnification spot views (magnification factor 1.9) of a state-of-the-art mammography system. The radiation exposure was measured and mean glandular doses were calculated. The contrast-detail resolution with both prototype (m = 1.7) and conventional (m = 1.1) survey views was equivalent while the entrance dose and the mean glandular dose were approximately 50 % lower with the prototype. For spot views, the contrast-detail resolution was substantially higher for the prototype than for conventional magnification while the dose was equivalent. Dose reduction and improved detail resolution are possible with this new technology.
Funke
M
M
Department of Radiology, Georg-August-Universität, Robert-Koch-Strasse 40, D-37 075 Göttingen, Germany.
Breiter
N
N
Hermann
K
K
Oestmann
J
J
Grabbe
E
E
D000180:Acrylic Resins; D001940:Breast / Q000528:radiation effects; D001943:Breast Neoplasms / Q000000981:diagnostic imaging; D002114:Calcinosis / Q000000981:diagnostic imaging; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008327:Mammography / Q000295:instrumentation* / Q000379:methods; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D011858:Radiographic Magnification; D013679:Technology, Radiologic / Q000295:instrumentation; D014963:X-Ray Intensifying Screens
D000180:Acrylic Resins