Assessment of hand superficial oxygenation during ischemia/reperfusion in healthy subjects versus systemic sclerosis patients by 2D near infrared spectroscopic imaging

Multispectral optoacoustic tomography of systemic sclerosis

“…Our results show reduced values of haemoglobin in subcutaneous finger tissue of patients with SSc compared to healthy volunteers. This observation is consistent with first experimental findings in SSc and generally in accordance with the current concept of microvascular dysfunction and subsequent development of DU . Second, we observed significantly reduced values of haemoglobin in patients with a progressive disease burden compared to SSc patients with a stable disease activity or healthy volunteers.…”

“…In this context, MSOT is a more objective and quantitative approach to measure involvement of peripheral extremities and focus on functional biomarkers, which reflect disease activity and might also mirror organ affection. In this context, optical techniques like near‐infrared spectroscopy have been evaluated for non‐invasive and quantitative imaging of microvascular dysfunction in SSc via assessment of oxygen saturation and blood flow in intradermal vessels showing promising results in line with our findings . However, in comparison to optoacoustic imaging optical approaches have a limited tissue penetration of 3 to 5 mm .…”

“…In this context, optical techniques like near‐infrared spectroscopy have been evaluated for non‐invasive and quantitative imaging of microvascular dysfunction in SSc via assessment of oxygen saturation and blood flow in intradermal vessels showing promising results in line with our findings . However, in comparison to optoacoustic imaging optical approaches have a limited tissue penetration of 3 to 5 mm . The hybrid US/MSOT approach, with its similar probe layout is not differently handled compared to common US and examination time does not exceed a standard US examination.…”

“…Since the degree of microvascular dysfunction is not only a predictor for the occurrence of digital ulcers (DUs) but also for systemic disease burden and mortality , imaging tissue oxygenation could provide a valuable non‐invasive biomarker. Recently, first studies evaluated optical techniques like near‐infrared spectroscopy for SSc imaging showing promising results in the assessment of microvascular dysfunction . However, these methods are limited to skin vessel imaging due to the restricted penetration depth of the light.…”

Vascular Leaking, a Pivotal and Early Pathogenetic Event in Systemic Sclerosis: Should the Door Be Closed?

“…Nailfold videocapillaroscopy (NVC) is one of the major components in the 2013 classification of SSc ( 74 ), demonstrating progressive loss of the peripheral vascular network, dilatation of capillaries, deficient vascular repair and inadequate angiogenesis ( 75 ). While NVC is efficient for measuring morphological microvascular changes (microangiopathy), other methods, such as Laser Doppler, thermography or Near Infrared Spectrometry ( 76 ), are essential for the assessment of functional blood flow abnormalities. Results published so far do not clearly define the mechanistic changes of glycocalyx, ECM, BM, vesiculo-vacuolar organelles, cellular junctions, cytoskeletal proteins, and/or vascular pericytes abnormalities.…”