Microscope-Integrated Quantitative Analysis of Intraoperative Indocyanine Green Fluorescence Angiography for Blood Flow Assessment

Abstract

Quantification of ICG-based fluorescence angiography appears to be useful for intraoperative monitoring of arterial patency and regional cerebral blood flow.

Semi-quantitative assessment of flow dynamics during indocyanine green video-angiography in the treatment of intracranial dural arteriovenous fistulas: how I do it

“…In the case of high flow AV shunts such as iDAVFs, especially when the angio-architecture is complex, interpretation of conventional IG-VA may be confusing because the human eye is not able to recognise the slight time difference of fluorescence peak between arteries, arterialised veins and non-arterialised veins [2,3]. The reliability of conventional IG-VA may be increased by colour maps and semi-quantitative analysis of IG transit curves with Flow 800 software that detects the arterialisation of each iDAVF draining vein, like in the illustrated case ( Fig.…”

“…2b-d, Video 1, Supplemental Digital Content 1). However, the semi-quantitative assessment of blood flow is restricted to the superficial vessels observed in the microscopic field [2]. When multiple sites of AV shunt are not included in one microscopic field of view, each fistulous site should be mapped separately.…”

“…Implementation of conventional IG-VA with the Flow800 software has been reported previously [1,2]. However, the parameters considered, namely transit time (time between the fluorescence peaks reached respectively in the reference artery and parenchyma) and rise time (time for fluorescence to increase from 10 to 90 % within the tissue), only demonstrate the consequences of treatment and do not provide information about the location of the fistula [1,5,7].…”

Indocyanine green video-angiography in neurosurgery: A glance beyond vascular applications

“…In fact, conventional ICG-VA gives information about vessel patency but not quantitative, time-dependent and spatially precise analysis of intravascular blood flow [14].Faber et al [24]and Kamp et al [66] thanks to the FLOW 800 imaging software (Carl Zeiss Surgical, Oberkochen, Germany) managed to create overview maps where ICG fluorescence was translated into colours from red (early appearance) to blue (late appearance). They developed color-coded maps of time to half-maximal peak that appeared to be of value for giving an overview of blood flow perturbations and distribution by extracting data already contained in conventional ICG-VA [25].…”

Application of motion history image (MHI) on dynamic fluorescent imaging for monitoring cerebral ischemia induced by occlusion of middle cerebral artery (MCA) in mouse brain

“…In order to overcome these limitations, in the present study we propose and validate the use of MHI algorithm to the dynamic fluorescent imaging (DF) data to visualize the hypoperfusion (decreased blood flow) during an acute cerebral ischemic event. The potential of fluorescent imaging techniques were widely applied in several biomedical applications [11,12] and for the study of cortical hemodynamic changes during induced occlusion of middle cerebral artery (MCA) in a mouse brain [1].…”