Diagnostic ability of apparent diffusion coefficients for lymphomas and carcinomas in the pharynx

Eur Radiol. 2007 Oct;17(10):2631-7. doi: 10.1007/s00330-007-0588-z. Epub 2007 Feb 16.


We evaluated the diagnostic ability of diffusion-weighted imaging for the differentiation between lymphomas and carcinomas in the pharynx and between carcinomas with different histological types in the pharynx. T1-weighted, fat-suppressed T2-weighted, and diffusion-weighted MR imaging was performed on 14 patients with pharyngeal lymphomas, 26 patients with carcinomas of the pharynx, 5 patients with adenoidal hypertrophy, and 22 patients with normal tonsils. Apparent diffusion coefficients (ADCs) were determined by using two b factors (500 and 1,000 s/mm(2)). The ADCs of lymphomas were significantly smaller (0.454 +/- 0.075 x 10(-3) mm(2)/s) than those of carcinomas (0.863 +/- 0.238 x 10(-3) mm(2)/s). The ADCs of poorly differentiated and undifferentiated carcinomas (0.691 +/- 0.149 x 10(-3) mm(2)/s) were significantly smaller than those of moderately differentiated and well-differentiated carcinomas (0.971 +/- 0.221 x 10(-3) mm(2)/s), but were significantly larger than those of lymphomas. When an ADC smaller than 0.560 x 10(-3) mm(2)/s was used for predicting lymphomas, we obtained the highest accuracy of 96%, with 100% sensitivity and 94% specificity, 86% positive predictive value, and 100% negative predictive value. Therefore, ADC measurements effectively differentiate lymphomas from carcinomas in the pharynx and could be a useful adjunct to biopsy-based development of treatment planning.

MeSH terms

  • Adult
  • Aged
  • Carcinoma, Squamous Cell / diagnosis*
  • Diagnosis, Differential
  • Diffusion Magnetic Resonance Imaging*
  • Female
  • Humans
  • Lymphoma, B-Cell / diagnosis*
  • Male
  • Middle Aged
  • Pharyngeal Neoplasms / diagnosis*