title: What is the pelvic lymph node normal size? Determination from normal MRI examinations.
abstract: OBJECTIVE
  There are few previous reports on maximal pelvic lymph node sizes and no data on normal mesorectal nodes. Therefore, the aim of the study was to estimate the normal size of pelvic lymph nodes and to determine the upper limits of the normal range.
  
  
  METHODS
  Pelvic magnetic resonance imaging (MRI) examinations were prospectively carried out using a Intera 1.5 T magnet (Philips, the Netherlands), on 36 healthy volunteers (22 females, 14 males, mean age 25 years). A balanced fast field echo (b-FFE) sequence was used with the following parameters: 3-mm-thick contiguous slice, matrix 512 × 512. Short axis diameters of pelvic and inguinal lymph nodes were measured in each anatomic territory (internal iliac, external iliac, common iliac, mesorectum and inguinal). After normalization of the measurements, the influences of age, gender, laterality and territory were evaluated. Upper limits (95th percentile) were then calculated.
  
  
  RESULTS
  A total of 1147 lymph nodes were measured. Age, gender and side (right/left) had no significant influence on size. The upper limits of the normal range were, respectively, 5.3, 4.4, 6.3 and 3.9 mm for the external and common iliac, internal iliac, inguinal and mesorectum nodes.
  
  
  CONCLUSIONS
  This work presents maximal normal values for each pelvic area, and the values for mesorectum nodes are reported for the first time.
  
  
  CONCLUSIONS
  The mesorectum nodes should be considered as abnormal when they are over 4 mm in short diameter. For the other node areas, the upper limits of the normal range were, respectively, 6, 6, 5, 7 mm for the external and common iliac, internal, iliac and inguinal nodes for the short axis.
authors.affiliation: Department of Imaging, University Hospital of Poitiers, Poitiers, France.
authors.forename: Marjorie
authors.initials: M
authors.lastname: Ramirez
authors.affiliation: Epidemiology and Biostatistics Laboratory, INSERM CIC-0802, University of Poitiers, Poitiers, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Ingrand
authors.affiliation: Anatomy and Simulation Laboratory, University of Poitiers, Poitiers, France.|Department of Abdominal Surgery, University Hospital of Poitiers, Poitiers, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Richer
authors.affiliation: Department of Imaging, University Hospital of Poitiers, Poitiers, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Herpe
authors.affiliation: Department of Imaging, University Hospital of Poitiers, Poitiers, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Vesselle
authors.affiliation: Department of Imaging, University Hospital of Poitiers, Poitiers, France.
authors.forename: Samy
authors.initials: S
authors.lastname: Boucebci
authors.affiliation: Department of Imaging, University Hospital of Poitiers, Poitiers, France. j.p.tasu@chu-poitiers.fr.|DACTIM, Research Unit on Functional Imaging, University of Poitiers, Poitiers, France. j.p.tasu@chu-poitiers.fr.|CHU Poitiers, Service d'imagerie médicale, 2 rue de la Milétrie, 86000, Poitiers, France. j.p.tasu@chu-poitiers.fr.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Tasu
mesh_terms: D000328:Adult; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008198:Lymph Nodes / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D010388:Pelvis / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D012016:Reference Values; D055815:Young Adult
keywords: Inguinal; Lymph nodes; MRI; Normal size; Pelvic