We describe a novel optical system for bidirectional color Doppler imaging of flow in biological tissues with micrometer-scale resolution and demonstrate its use for in vivo imaging of blood flow in an animal model. Our technique, color Doppler optical coherence tomography (CDOCT), performs spatially localized optical Doppler velocimetry by use of scanning low-coherence interferometry. CDOCT is an extension of optical coherence tomography (OCT), employing coherent signal-acquisition electronics and joint time-frequency analysis algorithms to perform flow imaging simultaneous with conventional OCT imaging. Cross-sectional maps of blood flow velocity with <50-μm spatial resolution and <0.6-mm/s velocity precision were obtained through intact skin in living hamster subdermal tissue. This technology has several potential medical applications.

In vivo bidirectional color Doppler flow imaging of picoliter blood volumes using optical coherence tomography

Medical retina, focus on retinal imaging, Eds. Frank G. Holz and Richard Spaide, 2010, pp. 227, cloth, EUR 171.15, ISBN-13: 978-3-540-85539-2 Springer-Verlag

Introduction: Retinal imaging in diabetic retinopathy has experienced significant advances since the days of the Early Treatment for Diabetic Retinopathy Studies. Differentiating intraretinal microvascular abnormalities (IRMA) from neovascular complexes remain a challenging part of disease staging but may become easier in this age of multimodal imaging.Areas covered: This review presents an overview of the available imaging modalities, their current applications and limitations as well as future developments in the pipeline. The implication of new imaging technology on the traditional definition of IRMAs and how this may translate into potential treatment outcomes for the patient will be discussed. This review is based on a literature search of all English language articles published on PubMed.Expert commentary: The characterisation of IRMA has evolved with the development of OCT to identify morphological differences. Wide field imaging may also identify IRMA outside of standard field of view of c...

Shahee Ahmed

Papers

Multimodal retinal imaging in the diagnosis of intraretinal microvascular abnormality