title: Diagnosis of inguinal lymph node metastases using contrast enhanced high resolution MR lymphangiography.
abstract: OBJECTIVE
  Inguinal lymph nodes can be the first or the only clinical signs of tumor metastases. The aim of the study was to evaluate the role of contrast-enhanced high-resolution magnetic resonance (MR) lymphangiography in diagnosis of inguinal lymph node metastases.
  
  
  METHODS
  The study enrolled 26 patients with inguinal lymph node metastases. Contrast-enhanced lymphangiography was performed using a 3.0T MR unit after intracutaneous injection of gadobenate dimeglumine into the interdigital webs of the dorsal foot. Images of inguinal lymph nodes were acquired before and after contrast injection.
  
  
  RESULTS
  All patients exhibited edema in the subcutaneous layer with significant dilatation of lymphatic collectors in the affected lower limbs on MR images. Before contrast injection, the outline and structure of the affected nodes were unclear on T2 weighted images. Structural changes became evident on postinjection T1-weighted images. Nodal involvement on contrast enhanced MR lymphangiograms was characterized as: 1) heterogeneous structure with partial or marginal enhancement of the node indicating partial occupation by tumor; 2) homogeneous structure of the node without contrast enhancement, indicating total occupation with metastasis, with increase or no change in size; and 3) heterogeneous structure with punctiform nodal enhancement indicating diffuse growth of tumor within the node. Further examinations confirmed the diagnoses of inguinal lymph node metastases of either regional or distal tumors.
  
  
  CONCLUSIONS
  Contrast-enhanced high-resolution MR lymphangiography was a sensitive modality in the diagnosis of malignant peripheral lymphedema and the identification of inguinal lymph node metastasis in patients with various tumor origins.
authors.affiliation: Lymphology Center, Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi Zao Ju Road, Shanghai 200011, China. liuningfei@126.com
authors.forename: Ningfei
authors.initials: N
authors.lastname: Liu
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Yan
authors.forename: Qing
authors.initials: Q
authors.lastname: Lu
authors.forename: Chenguang
authors.initials: C
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D007264:Inguinal Canal / Q000473:pathology*; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives*; D008875:Middle Aged; D009942:Organometallic Compounds; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine