Tri‐Compartmental Restriction Spectrum Imaging Based on 18F‐FDG PET/MR for Identification of Primary Benign and Malignant Lung Lesions

Abstract

BackgroundRestriction spectrum imaging (RSI), as an advanced quantitative diffusion‐weighted magnetic resonance imaging technique, has the potential to distinguish primary benign and malignant lung lesions.ObjectiveTo explore how well the tri‐compartmental RSI performs in distinguishing primary benign from malignant lung lesions compared with diffusion‐weighted imaging (DWI), and to further explore whether positron emission tomography/magnetic resonance imaging (PET/MRI) can improve diagnostic efficacy.Study TypeProspective.Population137 patients, including 108 malignant and 29 benign lesions (85 males, 52 females; average age = 60.0 ± 10.0 years).Field Strength/SequenceT2WI, T1WI, multi‐b value DWI, MR‐based attenuation correction, and PET imaging on a 3.0 T whole‐body PET/MR system.AssessmentThe apparent diffusion coefficient (ADC), RSI‐derived parameters (restricted diffusion , hindered diffusion , and free diffusion ) and the maximum standardized uptake value (SUVmax) were calculated and analyzed for diagnostic efficacy individually or in combination.Statistical TestsStudent's t‐test, Mann–Whitney U test, receiver operating characteristic (ROC) curves, Delong test, Spearman's correlation analysis. P < 0.05 was considered statistically significant.ResultsThe , SUVmax were significantly higher, and , ADC were significantly lower in the malignant group [0.717 ± 0.131, 9.125 (5.753, 13.058), 0.194 ± 0.099, 1.240 (0.972, 1.407)] compared to the benign group [0.504 ± 0.236, 3.390 (1.673, 6.030), 0.398 ± 0.195, 1.485 ± 0.382]. The area under the ROC curve (AUC) values ranked from highest to lowest as follows: AUC (SUVmax) > AUC () > AUC () > AUC (ADC) > AUC () (AUC = 0.819, 0.811, 0.770, 0.745, 0549). The AUC (AUC = 0.900) of the combined model of RSI with PET was significantly higher than that of either single‐modality imaging.ConclusionRSI‐derived parameters (, ) might help to distinguish primary benign and malignant lung lesions and the discriminatory utility of was not observed. The RSI exhibits comparable or potentially enhanced performance compared with DWI, and the combined RSI and PET model might improve diagnostic efficacy.Level of Evidence2.Technical EfficacyStage 2.