A Study of the Correlation of Perfusion Parameters in High-Resolution GRASP MRI With Microvascular Density in Lung Cancer.

Background The histological count of microvascular density (MVD) is the current clinical standard for assessing tumor angiogenesis. Although it is hypothesized that perfusion MRI can be a noninvasive alternative to MVD, there have been few studies to validate their correlations, particularly in lung cancer. Purpose To investigate the correlation between MVD and perfusion parameters obtained from high-resolution GRASP (Golden-angle RAdial Sparse Parallel) dynamic contrast-enhanced (DCE)-MRI in a cohort of lung cancer patients, and to validate that GRASP MRI can serve as a free-breathing, noninvasive imaging approach for studying tumor angiogenesis. Study Type Prospective. Population Twenty-five lung cancer patients (16 male, 9 female, mean age = 57.3 +/- 11.7 years). Field Strength/Sequence 3T MRI; a prototype golden-angle stack-of-stars sequence. Assessment Contrast-enhanced MR data were acquired during free breathing and were reconstructed using GRASP with a temporal resolution of similar to 3 sec/phase. For all data, perfusion analysis was performed using a standard Tofts model to generate the volume transfer coefficient (K-trans) and the interstitial volume (V-e). The MVD of corresponding tumor specimens, obtained from Computed Tomography-guided biopsies, were counted with CD34 staining. Statistical Tests Pearson correlation analysis; one-way analysis of variance analysis; least significant difference-t method of multiple comparisons. Results The correlation coefficient was 0.983 and 0.972 for the measurement and remeasurement of K-trans and V-e. The mean values of K-trans, V-e, and MVD were 0.33 +/- 0.22 min(-1), 0.25 +/- 0.12, and 49.68 +/- 27.08 vessels/0.723 mm(2), respectively, in all patients (n = 25); 0.36 +/- 0.26 min(-1), 0.27 +/- 0.13, and 49.09 +/- 29.84 vessels/0.723 mm(2), respectively, in adenocarcinoma (n = 15); 0.34 +/- 0.17 min(-1), 0.26 +/- 0.12, and 53.85 +/- 23.53 vessels/0.723 mm(2), respectively, in squamous cell carcinoma (n = 8); and 0.13 +/- 0.15 min(-1), 0.14 +/- 0.06, and 37.20 +/- 28.28 vessels/0.723 mm(2), respectively, in small-cell carcinoma (n = 2). There was a positive relationship between the K-trans and MVD in all patients (r = 0.738, P < 0.001). Data Conclusion High spatiotemporal resolution DCE-MRI using GRASP is a promising noninvasive alternative to the histological count of MVD for assessing tumor angiogenesis in lung cancer.