Figure 2: Digitally generated “sperm heat maps” of the (a) right and (b) left testicles showing the frequency of finding sperm by geographical location in each testis. The X-Y plane shows the relative location of found sperm in each testis FNA site. The vertical or Z-plane shows the relatively frequency of finding sperm at each FNA site. The higher the peak, the higher the frequency of found sperm at that site. Note that in each testicle, there is a dearth of found sperm in centrally located FNA sites compared with peripheral FNA sites. FNA: fine-needle aspiration.