Sumi M, Ichikawa Y, Nakamura T. Diagnostic ability of apparent diffusion coefficients for lymphomas and carcinomas in the pharynx.
Eur Radiol 2007;
17:2631-7. [PMID:
17429643 DOI:
10.1007/s00330-007-0588-z]
[Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 12/21/2006] [Accepted: 01/11/2007] [Indexed: 11/27/2022]
Abstract
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.
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