We modified and adapted a novel noncontact speckle contrast diffuse correlation tomography (scDCT) system, developed in our laboratory, for noninvasive 3D imaging of blood flow distributions in small animals and large human tissue volumes. The new system has the flexibility of selecting small and large regions of interest (ROIs) with different imaging depths for the use in both the small mouse head and large human mastectomy skin flaps. The capability of the upgraded scDCT system was demonstrated by continuous imaging of cerebral blood flow (CBF) changes in a small mouse head during sequential common carotid artery ligations and blood flow distributions in human mastectomy skin flaps during surgery. As expected, arterial occlusions resulted in substantial CBF decreases in deep brain tissues of the mouse. Spatial heterogeneity existed, and lower blood flow values were observed around the incision area of mastectomy skin flaps. The noncontact scDCT system with flexible ROIs and imaging depths has the potential to be used in many preclinical and clinical settings for noninvasive assessment of tissue hemodynamics and viability.