Correlation between Ultrasonographic Features and Morphological Pattern after Blue Dye Injection of Normal Superficial Lymph Nodes in Carnivores

Abstract

The present study performs a description of ultrasound anatomy of superficial lymph nodesusing gray scale ultrasound, Doppler techniques (color Doppler and power Doppler), compared with amorphological identification method - injection of coloring solutions (Blue Dye), with lymphatic tissuetropism. Eleven subjects were examined (nine female and two male). A total of 58 lymph nodes wereassessed belonging to the axillary, superficial inguinal, popliteus, superficial cervical and submandibularlymph centers. Ultrasonographic criteria followed were: shape, size, echogenicity, ecotexture, capsuleappearance, hiperecoic band of the hillum and angioarhitecture. For comparison, subcutaneous injectionof Blue Dye Evans, 0.5% in 4 subjects was performed. Ultrasound examination detected right and leftinguinal, and popliteus lymph nodes in all subjects, axillaries lymph nodes in 10 subjects, cervicalsuperficial lymph nodes in 9 subjects and submandibular in 7 subjects. Normal lymph nodes present oval(fusiform) shape, with a corticomedullary homogenous ecotexture, well defined capsule. The ecogenicitywas hypoecoic or isoecoic to the surrounding tissues, with a hiperecoic hilar band. The distribution ofvascular flow within the lymph node, assessed by color Doppler techniques, was hilar in 78% of subjects.Power Doppler technique detected with high accuracy the presence of vascular signal in small lymphvessels. Subcutaneous injection of Blue Dye, identified in all subjects the axillary, inguinal superficial,popliteus and cervical superficial lymph nodes. Compared with Blue Dye, ultrasound examinationrevealed with about the same accuracy the lymph nodes, with 96% specificity and 87% sensitivity.