鈷取代氫氧基磷灰石/明膠微球 混摻羧甲基纖維素 應用於醫學影像之研究

本研究探討微球化之鈷取代氫氧基磷灰石對於磁振造影成像中假影的影響，所使用之鈷取代氫氧基磷灰石透過電化學沉積法製備，並與羧甲基纖維素鈉及明膠混合後，通過乳化法形成微球，為增加微球之穩定性，再以京尼平進行化學交聯，形成具有均勻粒徑分布的複合微球。本研究使用氫氧基磷灰石、鈷取代氫氧基磷灰石粉體以及五種微球(明膠、明膠與兩種不同分子量羧甲基纖維素鈉以及明膠與低分子量羧甲基纖維素鈉包覆兩種粉體)進行磁振造影分析，每個組別設計不同重量放置於大型的明膠塊中，模擬生物體內的環境，再進行MRI掃描。研究的結果顯示氫氧基磷灰石粉體的MRI影像中呈現出輕微的假影，但影響程度較小。而鈷取代氫氧基磷灰石粉體由於含有金屬離子，對MRI影像產生了強烈的假影，嚴重影響了影像品質和判讀。其中不同重量的粉體對MRI假影的影響程度也不相同。經過微球化處理後的樣品中顆粒團聚現象減少，MRI中的假影面積顯著較粉體中少，使影像更加清晰和易於分析。以上結果證實微球化策略能在提高MRI影像質量和診斷準確性方面的潛力。

This study explores the effect of cobalt-substituted hydroxyapatite microspheres on artefacts in magnetic resonance imaging. The cobalt-substituted hydroxyapatite used is prepared by electrochemical deposition and combined with the mixture of sodium carboxymethylcellulose and gelatin, microspheres are formed through an emulsification method. To increase the stability of the microspheres, genipin is used for chemical cross-linking to form composite microspheres with a uniform particle size distribution. This study used hydroxyapatite, cobalt-substituted hydroxyapatite powder and five types of microspheres (gelatin, gelatin with two different molecular weight sodium carboxymethylcellulose, and two powders coated with gelatin and low molecular weight sodium carboxymethylcellulose) were used for magnetic resonance imaging analysis. Each group was designed with different weights and placed in large gelatin blocks to simulate the environment in the living body, and then MRI scanning was performed. The results of the study showed that the MRI images of the hydroxyapatite powder showed slight artefacts, but the impact was small. However, cobalt-substituted hydroxyapatite powder contains metal ions, which produce strong artefacts in MRI images, seriously affecting image quality and interpretation. Different weights of powders have different effects on MRI artefacts. The particle agglomeration in the sample after microsphere treatment is reduced, and the artefact area in the magnetic resonance imaging is significantly smaller than that in the powder, making the image clearer and easier to analyse. These results confirm the potential of the microsphere strategy to improve MRI image quality and diagnostic accuracy.