In-vivo Visualization of Iron Oxide Enhancement in Focal Pulmonary Inflammatory Lesions Using a Three-Dimensional Radial Gradient-Echo-Based Ultrashort Echo Time Sequence: A Preliminary Study
10.3348/kjr.2018.19.1.153
- Author:
Soon Ho YOON
1
;
Chanhee LEE
;
Jinil PARK
;
Jin Mo GOO
;
Jang Yeon PARK
Author Information
1. Department of Radiology, Seoul National University College of Medicine, Seoul 03080, Korea.
- Publication Type:Brief Communication
- Keywords:
Magnetic resonance imaging;
Nanoparticles;
Iron;
Macrophages;
Lung neoplasms;
Granuloma
- MeSH:
Ferrosoferric Oxide;
Granuloma;
Immunohistochemistry;
Iron;
Lung Diseases;
Lung Neoplasms;
Macrophages;
Magnetic Resonance Imaging;
Nanoparticles;
Rabbits
- From:Korean Journal of Radiology
2018;19(1):153-157
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: To preliminarily evaluate technical feasibility of a dual-echo ultrashort echo time (UTE) subtraction MR imaging by using concurrent dephasing and excitation (CODE) sequence for visualization of iron-oxide enhancement in focal inflammatory pulmonary lesions. MATERIALS AND METHODS: A UTE pulmonary MR imaging before and after the injection of clinically usable superparamagnetic iron-oxide nanoparticles, ferumoxytol, was conducted using CODE sequence with dual echo times of 0.14 ms for the first echo and 4.15 ms for the second echo on 3T scanner in two rabbits concurrently having granulomatous lung disease and lung cancer in separate lobes. A mean ratio of standardized signal intensity (SI) was calculated for comparison of granulomatous lesion and cancer at first echo, second echo, and subtracted images. Lesions were pathologically evaluated with Prussian blue and immunohistochemistry staining. RESULTS: Post-contrast subtracted CODE images visualized exclusive enhancement of iron oxide in granulomatous disease, but not in the cancer (mean ratio of SI, 2.15 ± 0.68 for granulomatous lesion versus 1.00 ± 0.07 for cancer; p value = 0.002). Prussian blue and corresponding anti-rabbit macrophage IgG-staining suggested an intracellular uptake of iron-oxide nanoparticles in macrophages of granulomatous lesions. CONCLUSION: Dual-echo UTE subtraction MR imaging using CODE sequence depicts an exclusive positive enhancement of iron-oxide nanoparticle in rabbits in focal granulomatous inflammatory lesions.
