The diagnostic accuracy of power Doppler ultrasonography for differentiating secondary from primary Raynaud’s phenomenon in undifferentiated connective tissue disease

Raynaud phenomenon and microvasculopathy in systemic sclerosis: multi-modality imaging for diagnosis and evaluation

PURPOSE OF REVIEW

To describe the clinical significance of and the diagnostic approach to Raynaud phenomenon (RP) in the peripheral extremities and the heart.

RECENT FINDINGS

Nailfold capillaroscopy has recently been standardized in an expert consensus paper. Abnormal capillaroscopy in combination with specific autoantibody profiles and clinical signs are highly predictive of progression of RP to systemic sclerosis (SSc). Magnetic resonance imaging (MRI) can also perform tissue characterization of both the extremities and the heart. Microvascular wall abnormalities detected using nailfold capillaroscopy in patients with SSc may lead to deposition of erythrocyte-derived iron, due to microhemorrhages, which may predispose to fibrosis. MRI can assess the presence of iron using T2∗ measurements.

SUMMARY

RP is a hallmark of the microvasculopathy in SSc and can affect both the peripheral extremities and the heart. Nailfold capillaroscopy is the current gold standard for the evaluation of the peripheral microvasculature. Other imaging modalities include thermography, laser Doppler-derived methods, 99m Tc-pertechnetate hand perfusion scintigraphy, power Doppler ultrasonography, dynamic optical coherence tomography, MRI, and photoacoustic imaging, but these are currently not widely used. Cardiac RP can be investigated with positron emission tomography or cardiovascular magnetic resonance, with the latter offering the additional possibility of tissue characterization and iron content quantification secondary to microhemorrhages.

The Promising Role of a Superb Microvascular Imaging Technique in the Evaluation of Raynaud's Syndrome in Systemic Sclerosis: Theory and Practical Challenges

In recent years, a novel Doppler ultrasonography (US) modality—superb microvascular imaging (SMI)—has been presented as a reliable method to evaluate small vessel blood flow with minimised motion artefacts. In this review, we present the challenges of incorporating SMI in daily practice with detailed and comparable US images of a fingertip. The main focus of this paper is the discussion of all tested US techniques, artefacts, and practical challenges for evaluating Raynaud’s syndrome in systemic sclerosis. Despite a few reports on SMI use in assessing nailfold capillaries, there is still a need for more evidence of its value and possibilities for its standardisation.

Position article and guidelines 2018 recommendations of the Brazilian Society of Rheumatology for the indication, interpretation and performance of nailfold capillaroscopy

Nailfold capillaroscopy (NFC) is a reproducible, simple, low-cost, and safe imaging technique used for morphological analysis of nail bed capillaries. It is considered to be extremely useful for the investigation of Raynaud's phenomenon and for the early diagnosis of systemic sclerosis (SSc). The capillaroscopic pattern typically associated with SSc, scleroderma ("SD") pattern, is characterized by dilated capillaries, microhemorrhages, avascular areas and/or capillary loss, and distortion of the capillary architecture. The aim of these recommendations is to provide orientation regarding the relevance of NFC, and to establish a consensus on the indications, nomenclature, the interpretation of NFC findings and the technical equipments that should be used. These recommendations were formulated based on a systematic literature review of studies included in the database MEDLINE (PubMed) without any time restriction.

Undifferentiated CTD: a wide spectrum of autoimmune diseases

The existence of systemic autoimmune diseases not fulfilling classification criteria for defined connective tissue diseases (CTDs) is a common clinical experience. These conditions have been variably defined as incomplete lupus erythematosus, early undifferentiated connective tissue diseases and undifferentiated connective tissue diseases (UCTDs). However, the definition of UCTD includes a wide spectrum of diseases ranging from 'organ-dominant' conditions (e.g., idhiopatic non-specific interstitial pneumonia) to simplified conditions (stable UCTD), to early CTDs or mild forms of CTDs. In the present article, the literature data on undifferentiated diseases and their clinical spectrum as well as the importance of the definition of new classificative criteria are discussed.

[Minimal work-up for Raynaud syndrome: a consensus report. Microcirculation Working Group of the French Vascular Medicine Society]

About ten to fifteen percent of the French population suffer from Raynaud's phenomenon. Most of the time, it is considered as primary Raynaud's phenomenon, without underlying disease. The aim of this expert consensus from the "microcirculation group" for the French Society of Vascular Medicine and the French Society for Microcirculation, was to define clinical guidelines in patients consulting for Raynaud's phenomenon. The recommended minimal screening includes clinical examination, nailfold capillaroscopy and antinuclear antibodies. In particular, the aim of this screening is to identify patients with a significant risk for scleroderma, who would need a careful follow up.

Capillaroscopy

Capillaroscopy is the most reliable way to distinguish between primary and secondary Raynaud's phenomenon (RP) through identification of an early pattern of systemic sclerosis (SSc). The presence of giant capillaries and microhaemorrhages on nailfold videocapillaroscopy (NVC) is sufficient to identify the scleroderma pattern (early), and an increase in these features and the addition of loss of capillaries (active pattern) is followed by neo-angiogenesis, fibrosis and 'desertification' (late pattern). The sensitivity of the American College of Rheumatology's classification criteria for SSc increases from 67% to 99% with the addition of these specific NVC abnormalities. Based on the appearance of the scleroderma pattern on NVC, almost 15% of patients shift from primary to secondary RP over a mean follow-up period of 29.4+/-10 months. Follow-up by NVC (every 6 months) is suggested for RP patients. A scoring system for NVC changes is available, and scores change significantly during follow-up of SSc patients. Several other NVC patterns have also been identified, such as in dermatomyosistis, systemic lupus eythaematosus, mixed connective tissue disease and antiphospholipid syndrome.