fig3
From: Contemporary approach to heavily calcified lesions: tools of the trade, challenges, and pitfalls

Figure 3. Detection of coronary calcium by IntraVascular ultraSound (IVUS). (A) shows superficial calcium protruding into the vessel lumen (white arrow). A calcium arc > 180° often results in a tight stenosis that can hardly be dilated without appropriate debulking (B). The red arrow in the (C) indicates a deep calcification.