Cutaneous microcirculation in preterm neonates: comparison between sidestream dark field (SDF) and incident dark field (IDF) imaging

Abstract

Incident dark field imaging (IDF) is a new generation handheld microscope for bedside visualization and quantification of microcirculatory alterations. IDF is the technical successor of sidestream dark field imaging (SDF), currently the most used device for microcirculatory measurements. In (pre)term neonates the reduced thickness of the skin allows non-invasive transcutaneous measurements. The goal of this study was to compare the existing device (SDF) and its technical successor (IDF) in preterm neonates. We hypothesized that IDF imaging produces higher quality images resulting in a higher vessel density. After written informed consent was given by the parents, skin microcirculation was consecutively measured on the inner upper arm with de SDF and IDF device. Images were exported and analyzed offline using existing software (AVA 3.0). Vessel density and perfusion were calculated using the total vessel density (TVD) proportion of perfused vessels (PPV) and perfused vessel density. The microcirculation images quality score was used to evaluate the quality of the video images. In a heterogeneous group of twenty preterm neonates (median GA 27.6 weeks, range 24–33.4) IDF imaging visualized 19.9 % more vessels resulting in a significantly higher vessel density (TVD 16.9 vs. 14.1/mm, p value < 0.001). The perfusion of vessels could be determined more accurately in the IDF images, resulting in a significant lower PPV (88.7 vs. 93.9 %, p value 0.002). The IDF video images scored optimal in a higher percentage compared to the SDF video images. IDF imaging of the cutaneous microcirculation in preterm neonates resulted in a higher vessel density and lower perfusion compared to the existing SDF device.

Microcirculatory assessment of patients under VA-ECMO

“…The use of a new generation hand-held microscopy device may have advantages, but also may have disadvantages. The advantage of the Cytocam IDF camera used in this study is that images are able to observe more capillaries (30 %) than the previous-generation sidestream dark field (SDF) cameras due to improved optics [22, 24]. In combination with a larger field of view (1.55 × 1.16 mm = about three times larger than the field of view of previous devices) of the new generation camera, it could be argued that this camera provides more accurate information concerning microcirculation alterations then previous-generation SDF camera.…”

“…The CytoCam device has a computer-controlled, high-resolution image sensor. Additionally, a CytoCam-IDF (incident dark field) device has a specifically designed microscopic lens that produces high-resolution images, showing approximately 30 % more capillaries than previous-generation devices [22–24]. The newly introduced lightweight (140 g versus previous devices weighing approximately 450 g) Cytocam-IDF device (with improved optics, a computer-controlled image sensor and illumination, and a more precise focusing mechanism) used in the present study allows for a faster and more stable and precise measurement to be made.…”

From cardiac output to blood flow auto-regulation in shock

“…Recently, a third generation handheld microscope, based on incident dark field (IDF) imaging, has been introduced (CytoCam, Braedius Medical, Huizen, the Netherlands). This technique is able to provide higher quality images than side stream dark field (SDF) imaging, visualizing approximately 20−30% more capillaries than the SDF device [63]. New software for microcirculation analysis is also available and is able to automatically detect density parameters, including flow evaluation (Total Vessel Density, Perfusion Vessel Density, Proportion of Perfused Vessels).…”

The vulnerable microcirculation in the critically ill pediatric patient

“…Recently, the CytoCam, which is based on incident dark field imaging, was introduced [67]. The CytoCam uses a different illumination technique and is smaller and lighter and has a higher optical resolution [68]. In preterm neonates, transcutaneous measurements using an incident dark field have been demonstrated to be superior to a sidestream dark field in terms of the detected number of vessels, and the perfusion of the vessels could also be more accurately detected [68].…”