Amide proton transfer imaging of glioblastoma, neuroblastoma, and breast cancer cells on a 11.7 T magnetic resonance imaging system
| Autor: | Minori Tanoue, Yoshichika Yoshioka, Shigeyoshi Saito, Yasushi Sakata, Takashi Hashido, Rikita Araki, Yusuke Takahashi, Hidetaka Kioka |
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| Rok vydání: | 2019 |
| Předmět: |
Biomedical Engineering
Biophysics H&E stain Mice Nude Breast Neoplasms Imaging phantom 030218 nuclear medicine & medical imaging Mice Neuroblastoma 03 medical and health sciences 0302 clinical medicine Nuclear magnetic resonance Egg White Cell Line Tumor Glioma Image Processing Computer-Assisted medicine Animals Humans Radiology Nuclear Medicine and imaging Magnetization transfer medicine.diagnostic_test Brain Neoplasms Phantoms Imaging Chemistry Brain Cancer Magnetic resonance imaging medicine.disease Amides Magnetic Resonance Imaging Rats Immunohistochemistry Female Protons Glioblastoma Chickens Neoplasm Transplantation 030217 neurology & neurosurgery |
| Zdroj: | Magnetic Resonance Imaging. 62:181-190 |
| ISSN: | 0730-725X |
| DOI: | 10.1016/j.mri.2019.07.005 |
| Popis: | Purpose The purpose of this study was (i) to determine the optimal magnetization transfer (MT) pulse parameter for amide proton transfer (APT) chemical exchange saturation transfer (CEST) imaging on an ultra-high-field magnetic resonance imaging (MRI) system and (ii) to use APT CEST imaging to noninvasively assess brain orthotopic and ectopic tumor cells transplanted into the mouse brain. Methods To evaluate APT without the influence of other metabolites, we prepared egg white phantoms. Next, we used 7–11-week-old nude female mice and the following cell lines to establish tumors after injection into the left striatum of mice: C6 (rat glioma, n = 8) as primary tumors and Neuro-2A (mouse neuroblastoma, n = 11) and MDA-MB231 (human breast cancer, n = 8) as metastatic tumors. All MRI experiments were performed on an 11.7 T vertical-bore scanner. CEST imaging was performed at 1 week after injection of Neuro-2A cells and at 2 weeks after injection of C6 and MDA-MB231 cells. The MT pulse amplitude was set at 2.2 μT or 4.4 μT. We calculated and compared the magnetization transfer ratio (MTR) and difference of MTR asymmetry between normal tissue and tumor (ΔMTR asymmetry) on APT CEST images between mouse models of brain tumors. Then, we performed hematoxylin and eosin (HE) staining and Ki-67 immunohistochemical staining to compare the APT CEST effect on tumor tissues and the pathological findings. Results Phantom study of the amide proton phantom containing chicken egg white, z-spectra obtained at a pulse length of 500 ms showed smaller peaks, whereas those obtained at a pulse length of 2000 ms showed slightly higher peaks. The APT CEST effect on tumor tissues was clearer at a pulse amplitude of 2.2 μT than at 4.4 μT. For all mouse models of brain tumors, ΔMTR asymmetry was higher at 2.2 μT than at 4.4 μT. ΔMTR asymmetry was significantly higher for the Neuro-2A model than for the MDA-MB231 model. HE staining revealed light bleeding in Neuro-2A tumors. Immunohistochemical staining revealed that the density of Ki-67-positive cells was higher in Neuro-2A tumors than in C6 or MDA-MB231 tumors. Conclusion The MTR was higher at 4.4 μT than at 2.2 μT for each concentration of egg white at a pulse length of 500 ms or 2000 ms. High-resolution APT CEST imaging on an ultra-high-field MRI system was able to provide tumor information such as proliferative potential and intratumoral bleeding, noninvasively. |
| Databáze: | OpenAIRE |
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