title: Significance of popliteal lymph nodes visualization during radionuclide lymphoscintigraphy for lower limb lymphedema.
abstract: OBJECTIVE
  To examine the frequency and significance of visualization of popliteal nodes during lymphoscintigraphy for the investigation of lower extremity swelling.
  
  
  METHODS
  Technetium-99m-labeled nanocolloid was injected subcutaneously in the first web spaces of both feet of 90 patients (24 males, 66 females; age range, 4-70 years) who had clinical evidence of lower limb lymphedema and were referred for routine lymphoscintigraphy; imaging was performed 5, and 90 minutes after injection without any vigorous exercise between the injection and imaging.
  
  
  RESULTS
  According to the scan findings, patients were divided into two groups; group I included 63 patients without popliteal nodes visualization on scanning, and group II included 27 patients with positive popliteal nodes uptake. None of patients with primary lymphedema (N = 22) due to agenesis or hypoplasia showed popliteal node uptake, whereas, patients with secondary lymphedema (N = 68) had either severe (N = 23) or partial (N = 45) lymphatic obstruction. A high positive association of popliteal node uptake with the severity of lymphatic obstruction was noted. Popliteal nodes were visualized in 26 of 57 patients with dermal back flow (46%), and in only 1 of 33 patients without dermal back flow (3%). There was a strong association between skin rerouting and popliteal node visualization (P < 0.01). Skin changes were detected in 24 patients (38%) with positive popliteal node uptake.
  
  
  CONCLUSIONS
  Popliteal lymph nodes uptake during lymphoscintigraphy for clinical lymphedema of the lower limb indicates lymph rerouting through the deep system and raises a diagnosis of higher severity and longer duration of lymphatic dysfunction.
authors.affiliation: Department of Nuclear Medicine, Kasr Al-Ainy Hospital (NEMROCK), Cairo, Egypt.
authors.forename: Ahmed Abdel-Samie
authors.initials: AA
authors.lastname: Kandeel
authors.forename: Jehan
authors.initials: J
authors.lastname: Ahmed Younes
authors.forename: Ahmed
authors.initials: A
authors.lastname: Mohamed Zaher
keywords: Lower limb edema; lymphoscintigraphy; popliteal lymph node