Bland Altman analyses comparing minimum luminal area (MLA; upper panel) and diameter (MLD; lower panel) obtained using FD-OCT and IVUS. FD-OCT, frequency domain optical coherence tomography; IVUS, intravascular ultrasound. Bland Altman analyses comparing minimum luminal area (MLA; upper panel) and diameter (MLD; lower panel) obtained using FD-OCT and IVUS. FD-OCT, frequency domain optical coherence tomography; IVUS, intravascular ultrasound. Ingibjorg Gudmundsdottir et al. Open Heart 2015;2:e000225 ©2015 by British Cardiovascular Society