KLK3 and posterior cortical atrophy: However, CT and MRI/TRUS are not capable of the early-stage detection of PCa, whereas PSA is prostate-specific, not cancer-specific; hence, the use of PSA also has its limitations, such as organ-specific, small quantities present in blood serum of healthy men, altered level due to infection or another benign prostatic hyperplasia (BPH), and prostatitis or diet alteration which results in false positives [9].