AIM: To identify adult inguinal lymph node anatomical subgroups using magne
tic resonance imaging (MRI), to derive a normal range for nodal number and
size and to describe their morphology.
MATERIALS AND METHODS: Eighty-three oncology patients with low stage pelvic
tumours had inguinal lymph node assessment bg MRI, Nodes were divided into
proximal superficial (PS), distal superficial (DS) and deep inguinal (DT)
subgroups, their number counted in two planes, and their transaxial short a
xis diameter recorded, Consistency of the largest node was recorded for eac
h anatomical subgroup and two vertical distances measured, between the skin
surface and the ipsilateral pubis, and between the skin surface and the de
epest node.
RESULTS: Transaxial plane maximum nodal number at the three sites was: PS 5
, DS 8, DI 3; and in the coronal plane: PS 7, DS 5, DI 3, Nodal size ranges
were: PS 3-10 mm (mean 4 mm), DS 3-15 mm (mean 6 mm) and DI3-10 mm (mean 6
mm), There was no correlation between nodal size or number and age or gend
er. Nodes were usually uniformly solid (PS 44%; DS 37%,DT 45%), or fatty (P
S 39%; DS 33%; DI 25%). The range of distances between the skin and deepest
lymph node was 2.5-16 cm depending on patient fatness.
CONCLUSION: The mean number of nodes counted in the axial plane was six and
in the coronal plane five. A maximum short axis diameter of 15 mm was reco
rded for inguinal lymph nodes. (C) 2000 The Royal College of Radiologists.