Value of diffusion-weighted imaging to detect small malignant pelvic lymph nodes at 3 T

Eur Radiol. 2010 Aug;20(8):1803-11. doi: 10.1007/s00330-010-1736-4. Epub 2010 Feb 24.


Objective: To investigate the usefulness of diffusion-weighted imaging (DWI) to discriminate between metastatic and non-metastatic small lymph nodes in pelvic carcinoma.

Materials and methods: A total of 259 patients (180 normal, 79 metastatic) prospectively underwent DWI at 3 T. We measured the short-axis diameter and the mean apparent diffusion coefficient (ADC) value. Lymph nodes with a short-axis diameter larger than 8 mm were recorded as being suspected metastatic lymph nodes. Imaging data were correlated station by station with histopathological results.

Results: A total of 140 metastatic nodes were accurately matched with histology. On T2w, the short-axis diameter for non-metastatic and metastatic lymph nodes was 6.4 mm +/- 2.5 mm and 8.3 mm +/- 4.5 mm, respectively. Almost all metastatic or non-metastatic nodes had similar high signal intensity on DWI (except in 5 cases) with a homogeneous pattern. The mean ADC values (10(-3) mm(3)/s +/- standard deviation) of involved lymph nodes, control iliac nodes and control inguinal nodes were 924 +/- 217, 968 +/- 182 and 1,036 +/- 181, respectively. There were no statistically significant differences in the ADC of metastatic and non-metastatic nodes.

Conclusion: Isolated measurement of mean ADC values in a suspected station does not contribute to the diagnosis of metastatic nodes, in patients with small ambiguous nodes.

MeSH terms

  • Adult
  • Aged
  • Diffusion Magnetic Resonance Imaging / methods*
  • Female
  • Humans
  • Lymph Nodes / pathology*
  • Lymphatic Metastasis
  • Male
  • Middle Aged
  • Pelvic Neoplasms / diagnosis*
  • Pelvic Neoplasms / secondary*
  • Reproducibility of Results
  • Sensitivity and Specificity