Role of Color Doppler and Microvascular Flow Imaging in the Assessment of Mesenteric Lymph Nodes in Pediatric...

Introduction Pediatric mesenteric lymph nodes are frequently evaluated using ultrasonography in children presenting with abdominal pain. While Color Doppler is routinely used to assess intranodal vascularity, its limited ability to detect slow-flow microvascular signals may reduce diagnostic sensitivity. Microvascular Flow Imaging (MVFI) has emerged as an advanced Doppler technique capable of visualizing low-velocity blood flow with greater sensitivity. The present study aimed to evaluate the role of Color Doppler and Microvascular Flow Imaging in the assessment of mesenteric lymph nodes in pediatric patients and to compare their performance in detecting intranodal vascularity, vascularity grading, lymph node morphology, and diagnostic agreement. Materials and methods This prospective observational study was conducted in the Department of Radio Diagnosis at Vydehi Institute of Medical Sciences and Research Centre, Bengaluru, India, between May 2024 and December 2025. A total of 90 pediatric patients aged 2-15 years with clinically suspected mesenteric lymphadenopathy underwent grayscale ultrasonography, Color Doppler, and MVFI. The largest representative mesenteric lymph node was evaluated for morphological characteristics, vascularity, and vascularity grading. Diagnostic agreement was assessed using Cohen's kappa analysis, and the diagnostic performance of Color Doppler was evaluated using MVFI as the reference standard. Results The majority of patients belonged to the 6-10-year age group (43 {47.8%}), with a slight male predominance (51 {56.7%}). Abdominal pain was the most common presenting symptom (77 {85.6%}). Most lymph nodes demonstrated an oval morphology (79 {87.8%}) with preserved fatty hilum (80 {88.9%}). MVFI detected vascularity in 81 (90.0%) patients compared with 67 (74.4%) using Color Doppler (p = 0.004). Higher vascularity grades (G2/G3) were more frequently identified with MVFI, and lymph nodes demonstrating vascularity had significantly larger long-axis and short-axis diameters (p < 0.001). Color Doppler demonstrated a sensitivity of 82.7% (95% confidence interval {CI}: 72.7%-90.2%), specificity of 100.0% (95% CI: 66.4%-100.0%), diagnostic accuracy of 84.4% (95% CI: 75.3%-91.2%), and moderate agreement with MVFI (Cohen's κ = 0.52; p < 0.001). Conclusion Microvascular Flow Imaging demonstrated superior detection of intranodal vascularity compared with conventional Color Doppler and provided additional information for the characterization of mesenteric lymph nodes. When used as an adjunct to routine grayscale ultrasonography, MVFI may improve diagnostic confidence in children presenting with suspected mesenteric lymphadenopathy.