Quantitative Investigation of Solitary Pulmonary Nodules: Dynamic Contrast-Enhanced MRI and Histopathologic Analysis

Abstract

Dynamic MRI values reflect the quantitative and morphologic characteristics of microvessels in SPNs and are a useful tool for differentiating SPNs with little overlap.

Evaluation of Indeterminate Pulmonary Nodules with Dynamic MR Imaging

“…Zou and associates 10 reported the steepest slope of benign pulmonary nodules to be signiˆcantly lower than that of malignant or active in‰ammato-ry nodules. And overlap of early enhancement characteristics between lung cancer and active in‰am-matory nodules by dynamic MR imaging or CT is reported.…”

“…Granuloma and tuberculoma are considered to be less active in‰ammatory nodules, 3,4 and in our study, granuloma and tuberculoma were the primary constituents of benign pulmonary nodules,ˆndings similar to those of other reports. 2,3,6,8,10 Several recent dynamic MR imaging studies have examined early enhancement followed by washout in pulmonary nodules 5,8,9 and focused only secondarily on washout after contrast enhancement. They …”

“…[6][7][8] More recently, researchers using MR imaging reported the absence of washout in most active in‰ammatory and benign nodules at the second or fourth minute from initiation of contrast injection. 9,10 However, these dynamic studies were retrospective, and washout characteristics after 4 min were unclear. Therefore, there is no evidence to indicate whether the characteristics of early enhancement and washout using dynamic MR imaging could distinguish indeterminate pulmonary nodules.…”

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Purpose: We prospectively assessed whether enhancement characteristics on dynamic magnetic resonance (MR) imaging could distinguish indeterminate pulmonary nodules.Methods: We evaluated 51 pulmonary nodules in 51 consecutive patients (11 female, 40 male; mean age, 64 years) using dynamic MR images acquired at 0,10, 20, 30, 40, 50, 60, 70, 80, 90, 120, 150, 180, 210, 240, 360, 480, 600, 720, and 840 s following injection of contrast material. We prospectively evaluated morphologic enhancement patterns, peak rate, time to peak enhancement, steepest slope, and washout of nodules and analyzed statistics to determine any diŠerences between MR parameters, patient age, tumor size, andˆnal diagnosis.

Results: We found 25 malignant, 12 active in‰ammatory, and 14 benign nodules.

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Clinical Application of MRI in Children for the Assessment of Pulmonary Diseases

“…In addition to the morphological characterization of a lesion, dynamic contrast-enhanced MRI is helpful for differentiating benign from malignant solitary pulmonary nodules. The absence of significant enhancement is a strong predictor that a lesion is benign [41,42] (• ▶ Fig. 16).…”