Non-invasive imaging of microcirculation: a technology review

Abstract

Microcirculation plays a crucial role in physiological processes of tissue oxygenation and nutritional exchange. Measurement of microcirculation can be applied on many organs in various pathologies. In this paper we aim to review the technique of non-invasive methods for imaging of the microcirculation. Methods covered are: videomicroscopy techniques, laser Doppler perfusion imaging, and laser speckle contrast imaging. Videomicroscopy techniques, such as orthogonal polarization spectral imaging and sidestream dark-field imaging, provide a plentitude of information and offer direct visualization of the microcirculation but have the major drawback that they may give pressure artifacts. Both laser Doppler perfusion imaging and laser speckle contrast imaging allow non-contact measurements but have the disadvantage of their sensitivity to motion artifacts and that they are confined to relative measurement comparisons. Ideal would be a non-contact videomicroscopy method with fully automatic analysis software.

Effects of volume resuscitation on the microcirculation in animal models of lipopolysaccharide sepsis: a systematic review

“…Microcirculatory assessment by sidestream dark-field imaging presented in this review exhibited heterogeneous effects in different tissues in one study [68], but no improvement in another [51]. Comparisons of different microcirculatory imaging techniques have been reported in literature [41, 74–76]. Investigators who conducted a comparative study on cochlear blood flow concluded that intravital microscopic measurements were more sensitive than laser Doppler measurements [77].…”

“…We considered some of these, including videomicroscopic techniques, whilst offering direct visualization of the microcirculation, the tissue contact element is largely uncontrolled and may cause pressure-induced artefacts. On the other hand, laser techniques are susceptible to motion artefacts, so that combining techniques might enhance the accuracy of microcirculatory assessments [76]. Only one study presented in this review used a combination of techniques to assess the microcirculation (i.e., laser Doppler flowmetry and sidestream dark-field imaging) and reported persistent acidosis, microcirculatory and mitochondrial dysfunction despite resuscitation with hydroxyethyl starch (HES) fluid [15].…”

Multiorgan, Multimodality Imaging in Cardiometabolic Disease

“…Capillary video microscopy is an optical imaging technique that uses green-spectrum light to illuminate superficial micro vessels in the nail beds. Detectors capture backscattered light and images are reconstructed producing images of capillaries 52 . Contrast-enhanced ultrasound can be used to quantify microvascular recruitment in deeper tissues, like skeletal muscle.…”

Icrocirculatory changes in bulbar conjunctiva in various diseases

“…К методам исследования микроциркуляции бульбар-ной конъюнктивы глаза относятся: биомикроскопия, фо-тографирование и кинематография микрососудов конъ-юнктивы, телевизионная биомикроскопия микрососудов глаза [2], флюоресцентная ангиография переднего отрез-ка глаза [7], лазерная спекл-контрастная визуализация [8], ортогональная поляризация спектральных изображе-ний [9], боковая темнопольная визуализация [10], ком-пьютерная телевизионная микроскопия [11], лазерная допплеровская флоуметрия [12], измерение диаметра конъюнктивальных сосудов с помощью Retinal Vessel Analyzer (RVA, Imedos, Германия) [13].…”

“…Методы чувствительны к артефактам движения и не учи-тывают гетерогенность кровотока, основного параметра микроциркуляции. Для выражения результатов использу-ются относительные единицы [10,17]. Лазерная доппле-ровская флоуметрия является неинвазивным методом определения микроциркуляции, в том числе и кожной [18].…”