Saved Bookmarks
| 1. |
Regarding mammography units: a. Spatial resolution is 8–10 line pairs mm-1 b. The anode is on the chest wall side c. The focal spot size for the magnified view is 0.3 mm d. The axial ray is directed to the centre of the X-ray fielde. The focus-to-film distance (FFD) is fixed in mammography |
|
Answer» a. False. Spatial resolution is 15 line pairs mm-1 or above. b. False. The cathode is on the chest wall side. c. False. For the magnified view, the smaller focal spot size is used, which is 0.1–0.15 mm. The larger one (0.4 mm) is for the standard view. d. False. The tube is angled so that the axial ray is at the chest wall edge; this helps to produce films with a more uniform density. e. True. Unlike general X-ray equipment, the distance between the tube head and the film cannot usually be varied. This is because the set is designed for a single examination and the focus-to-film distance used is considered the optimum. The normal FFD is 65 or 66 cm. |
|