Objective: The objective of our study was to use Doppler sonography to detect the flow characteristics and parameters of the hand arteries that are needed to distinguish between primary Raynaud phenomenon (RP) and secondary RP.
Subjects and methods: The diameter, resistive index (RI), and flow volume of the digital, ulnar, and radial arteries of patients with primary RP and those with secondary RP were measured at rest and after cold provocation. The flow starting time in the digital artery and the flow normalizing time of all three arteries were also recorded after cold provocation.
Results: At baseline and after cold provocation, the diameters of the radial and digital arteries and the flow volumes of the three arteries were less in patients with secondary RP than in primary RP patients. In primary RP and secondary RP, the flow normalizing times (mean ± SD) were 9.8 ± 3.88 and 25.88 ± 7.14 minutes, respectively, in the radial artery; 11.3 ± 7.43 and 32.15 ± 12.57 minutes in the ulnar artery; and 12.22 ± 6.82 and 32.67 ± 10.76 minutes in the digital artery. A flow normalizing time cutoff in the radial artery of 17 minutes yielded a sensitivity of 90% and specificity of 100%. A flow normalizing time cutoff in the ulnar artery of 23 minutes yielded a sensitivity and specificity of 71% and 100%, respectively. A flow normalizing time cutoff in the digital artery of 23 minutes yielded a sensitivity and specificity of 82.6% and 98%, respectively. The flow starting time of the digital artery was 3.80 ± 3.27 minutes in primary RP and 16.78 ± 9.97 minutes in secondary RP (p < 0.0001). The flow starting time cutoff of the digital artery was 7 minutes (sensitivity, 82.6%; specificity, 95.7%).
Conclusion: The diameter of the radial and distal arteries; flow volume; and flow volume normalizing time of the digital, ulnar, and radial arteries' flow starting time in the digital artery may be helpful in distinguishing between primary RP and secondary RP with high sensitivity and specificity values. These parameters may also facilitate objective follow-up of treatment. The noninvasive nature of Doppler sonography is an additional advantage, and there is no need for extra hardware or software.