Faculty Bibliography

Purpose: To evaluate mixed ground glass nodules (GGNs) utilizing 3 Tesla (T) MRI and 32-channel torso-array-coil and to correlate non-echo planar diffusion weighted imaging (DWI) and T2^* measurements with pathologic findings. Materials and Methods: Twelve patients with 13 GGNs >1cm in diameter detected on computed tomography were prospectively recruited for this Institutional Review Board approved study. T1-weighted 2D gradient echo (GRE), T2-weighted 2D turbo spin echo with fat saturation, T2^*-weighted multiple GRE, and diffusion weighted single shot twice-refocused spin echo axial images of the GGNs were acquired at end inspiration without intravenous contrast. Apparent diffusion coefficient (ADC) and T2^* values were determined and correlated to pathology. Results: All GGNs were visualized with the T2-weighted 2D TSE sequence providing the best morphologic delineation. Pathology was available for 9 of 13 lesions. ADC ranged from 1.19 to 1.78 mum²/ms (mean 1.45+/-0.19) and T2^* ranged from 6.78 to 27.81 mum²/ms (median 16.13, mean 16.68+/- 7.19) for the 7 malignant lesions. ADC was 1.59 and 1.42 and T2^* was 6.78 and 20.24 for the 2 malignant lesions with positive epidermal growth factor receptors. ADC ranged from 0.9 to 1.47 mum²/ms (mean 1.18 +/-0.4) and T2^* ranged from 6.87 to 10.93 (mean 8.9 +/-2.87) for the 2 benign lesions. Conclusion: 3T MRI with a 32-channel torso-array-coil provides a radiation free means of GGN evaluation. The T2-weighted 2D TSE with fat saturation sequence yields the best lesion visibility. DWI and T2^* measurements may provide quantitative measures for distinguishing malignant from benign nodules