High‐resolution Doppler ultrasound in systemic sclerosis: Analysis of digital arteries and nailfold microvasculature using 18‐5 MHz and 33‐9 MHz probes

Abstract

Introduction Newly developed Doppler techniques enable the sampling of slow vascular flows and the extrapolation of spectral parameters in distal arterioles. The aim of this study was to investigate the role of spectral analysis performed by means of ultra‐high frequency ultrasound (US) in the evaluation of the peripheral vascular bed of systemic sclerosis (SSc) patients. Methods Both hands of 33 patients affected by diffuse cutaneous SSc and 34 volunteers were evaluated with a US machine equipped with 33‐9 MHz and 18‐5 MHz transducers. Proximal resistive index and the peak systolic velocity (pRI and pPSV, respectively), were calculated at the level of the second interdigital artery. The distal resistive index (dRI) was calculated at the level of a nailfold arteriole of the third finger. All SSc patients had been previously divided into 4 subgroups according to their nailfold videocapillaroscopic (NVC) patterns following accepted criteria. Results SSc patients showed a significantly slower systolic velocity at the level of the second interdigital artery (pPSV [SD] = 8.38 [3] cm/s vs pPSV [SD] = 11.14 [4.5] cm/s; P = .005) and a higher dRI (dRI [SD] = 0.65 (0.14) vs dRI [SD] = 0.57 [0.11); P = .0115). No differences were found between the pRI values measured in the SSc patients and those of the controls (pRI [SD] = 0.76 [0.11] vs pRI [SD] = 0.73 [0.12]; P = .359]. The subgroup analysis did not show any significant difference when pPSV, pRI and dRI were compared among NVC morphological patterns. Conclusion High‐resolution Doppler analysis of digital distal arterioles may disclose subtle abnormalities in the downstream microvasculature of SSc patients that could be missed when the examination is performed at a more proximal level and/or using lower Doppler frequencies.

Botulinum toxin injection for refractory Raynaud phenomenon and digital ulcers in systemic sclerosis

“…As for tissue perfusion, it was measured by methods such as change in blood flow with laser Doppler imaging and pulse oximetry. Picasso et al 10 suggested that a newly developed ultrasound technique using ultra‐high frequency has the potential to disclose subtle abnormalities in distal digital arterioles. The study by Bello et al 4 was one of the best‐conducted studies in which blood flow change was set as the primary outcome.…”

Correlation between Microvascular Damage and Internal Organ Involvement in Scleroderma: Focus on Lung Damage and Endothelial Dysfunction

“…In fact, in addition to its use to assess skin thickness [55], evidence is emerging on this new purpose of ultrasound in SSc. Specifically, in patients with SSc, evaluation of the resistive index (RI) and peak systolic velocity (PSV) of interdigital arteries and nail arterioles using high-resolution ultrasound appears to be of some use in assessing subtle abnormalities in the downstream microvasculature [92]. However, pRI (Proximal Resistive Index) of the interdigital arteries does not seem to contribute to the detection of an ongoing pathological process in the small nail arterioles [92,93].…”

“…Specifically, in patients with SSc, evaluation of the resistive index (RI) and peak systolic velocity (PSV) of interdigital arteries and nail arterioles using high-resolution ultrasound appears to be of some use in assessing subtle abnormalities in the downstream microvasculature [92]. However, pRI (Proximal Resistive Index) of the interdigital arteries does not seem to contribute to the detection of an ongoing pathological process in the small nail arterioles [92,93]. In addition, Power Doppler UltraSound (PDUS) may play a role in predicting digital ulcers by detecting ulnar artery occlusion and pathological blood flow in the finger pulp [21].…”

Ultrasound quantitative assessment of ventral finger microvasculopathy in systemic sclerosis with Raynaud’s phenomena: a comparative study

“… 22 The peak systolic velocity and distal resistive index obtained from digital arteries and nail fold area using spectral Doppler imaging differentiated the patients with SSc from healthy controls. 23 …”