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Clinical application of pharmacokinetic analysis as a biomarker of solitary pulmonary nodules: Dynamic contrast‐enhanced MR imaging
Author(s) -
Mamata Hatsuho,
Tokuda Junichi,
Gill Ritu R.,
Padera Robert F.,
Lenkinski Robert E.,
Sugarbaker David J.,
Butler James P.,
Hatabu Hiroto
Publication year - 2012
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.24150
Subject(s) - dynamic contrast , contrast (vision) , biomarker , medicine , magnetic resonance imaging , dynamic contrast enhanced mri , pharmacokinetics , nuclear medicine , radiology , nuclear magnetic resonance , chemistry , computer science , physics , artificial intelligence , biochemistry
The purpose of this study is to evaluate perfusion indices and pharmacokinetic parameters in solitary pulmonary nodules (SPNs). Thirty patients of 34 enrolled with SPNs (15–30 mm) were evaluated in this study. T1 and T2‐weighted structural images and 2D turbo FLASH perfusion images were acquired with shallow free breathing. B‐spline nonrigid image registration and optimization by χ 2 test against pharmacokinetic model curve were performed on dynamic contrast‐enhanced MRI. This allowed voxel‐by‐voxel calculation of k ep , the rate constant for tracer transport to and from plasma and the extravascular extracellular space. Mean transit time, time‐to‐peak, initial slope, and maximum enhancement ( E max ) were calculated from time–intensity curves fitted to a gamma variate function. After blinded data analysis, correlation with tissue histology from surgical resection or biopsy samples was performed. Histologic evaluation revealed 25 malignant and five benign SPNs. All benign SPNs had k ep < 1.0 min −1 . Nineteen of 25 (76%) malignant SPNs showed k ep > 1.0 min −1 . Sensitivity to diagnose malignant SPNs at a cutoff of k ep = 1.0 min −1 was 76%, specificity was 100%, positive predictive value was 100%, negative predictive value was 45%, and accuracy was 80%. Of all indices studied, k ep was the most significant in differentiating malignant from benign SPNs. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.