MBI study performed with injection of 320 MBq Tc-99 m sestamibi and a dual-head DC-MBI system. In this 45-year-old woman, a 0.5-cm invasive ductal carcinoma appears as a mild intensity, focal area of non-mass uptake (arrow). Image count density of 1,800 counts/cm2 in the 10-min-per-view acquisition was considered high. The cancer was detected at (A) 10-min-per-view, but not at (B) 5 min-per-view or (C) 5 min-per-view with WBR. At 10 min-per-view, one reader assigned a test positive assessment of 4 (suspicious), and the other reader gave a test negative assessment of 3 (probably benign). For both 5 min-per-view and 5-min-per-view WBR acquisitions, both readers assigned test negative assessments of 2 (benign). These images correspond with patient no. 4 in Table 3.