Nuclear Cardiology: Nuclear Cardiology:

260 Nuclear Cardiology, The BasicsFig. 17-5. Bar phantom. All lines are straight, indicating appropriate linearity.The bar phantom can also be used as a quick check on resolution. In the phantomshown, the lines in three of four quadrants are well separated and visible. Evensmallest bars can be made out as a linear pattern, although they are notclearly separated. For daily QC it is important to document and record gradualchanges in camera performance.Fig. 17-6. Bar phantom showing wavy poor linearity. Nevertheless, resolutionis apparently not affected. The gamma camera needs to be tuned-up by thevendor’s maintenance service.