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Diffusion‐weighted quantitative MRI to diagnose benign conditions from malignancies of the anterior mediastinum: Improvement of diagnostic accuracy by comparing perfusion‐free to perfusion‐sensitive measurements of the apparent diffusion coefficient
Author(s) -
Priola Adriano Massimiliano,
Priola Sandro Massimo,
Gned Dario,
Piacibello Edoardo,
Sardo Diego,
Parvis Guido,
Torti Davide,
Ardissone Francesco,
Veltri Andrea
Publication year - 2016
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.25203
Subject(s) - medicine , perfusion , radiology , effective diffusion coefficient , diffusion mri , diffusion , anterior mediastinum , mediastinum , intravoxel incoherent motion , nuclear medicine , magnetic resonance imaging , physics , thermodynamics
Purpose To compare perfusion‐free to perfusion‐sensitive measurements of the apparent diffusion coefficient (ADC) to diagnose benign conditions from malignancies of the anterior mediastinum. Materials and Methods Seventy‐six subjects were divided into a “benign conditions” group (A, n = 44) and a “malignancies” group (B, n = 32), based on histological findings. diffusion‐weighted magnetic resonance imaging (DW‐MRI) was performed at b of 0/150/800 sec/mm 2 . The ADCs were obtained on an ADC map by including (perfusion‐sensitive = ADC b0‐800 ) and excluding (perfusion‐free = ADC b150‐800 ) the b = 0 sec/mm 2 . The Mann–Whitney U ‐test was used to detect differences in ADC b0‐800 compared with ADC b150‐800 values between all cases, benign conditions, and malignancies. The same test was used to evaluate differences in ADCs between the two groups for each type of measurement (ADC b0‐800 and ADC b150‐800 ), and receiver‐operating characteristic (ROC) curves were obtained to evaluate discrimination abilities with comparison of areas‐under‐ROC‐curves (AUROC). Optimal cutpoints for discrimination between groups were determined by the Youden‐Index with computation of accuracy. Results The median ADC b0‐800 was significantly greater compared with ADC b150‐800 for all cases ( P = 0.0014), benign conditions ( P = 0.0412), and malignancies ( P = 0.0001). The median percentage of increase was 5.30% for group‐A and 22.39% for group‐B ( P < 0.0001). AUROC of ADC in discriminating between groups was significantly greater for ADC b150‐800 (0.932) compared with ADC b0‐800 (0.831) ( P = 0.001). The optimal cutpoint for distinction between groups was 1.52 × 10 ‐3 mm 2 /sec (sensitivity = 93.7%, specificity = 88.6%, accuracy = 90.8%) for ADC b150‐800 and 1.75 × 10 ‐3 mm 2 /sec (sensitivity = 75.0%, specificity = 79.5%, accuracy = 77.6%) for ADC b0‐800 . Conclusion The use of perfusion‐free ADC measurements significantly improves diagnostic accuracy of DW‐MRI in differentiating benign conditions from malignancies of the anterior mediastinum. J. Magn. Reson. Imaging 2016;44:758–769.