تحديد عوامل التباين الفموية المؤثرة في تصوير الجهاز الهضمي بالرنين المغناطيسي

Identification of Effective Oral Contrast Agents for Gastrointestinal Magnetic Resonance Imaging

ABSTRACT

Magnetic resonance imaging (MRI) has limited use in abdominal imaging since it is difficult to distinguish the alimentary system from normal organs and intra-abdominal lesions. To enhance the vision of inaccessible organs, contrast chemicals are necessary for particular organs, such as gastrointestinal (GI) imaging. Traditionally contrast agents are very expensive, have side effects, and are not always available in Iraqi hospitals. The purpose of this study is to find alternative traditional oral contrast agents that may be employed in MRI of the alimentary tract. These contrast agents must be available, with no or little adverse effects, and non-expensive, modified in water signal intensity during alimentary imaging by MRI to result in high contrast and the best image quality.
The work procedure is summarized by collecting mineral supplements: such as iron, magnesium, potassium, calcium, zinc, sodium, and manganese. Then grinding and dissolving mineral supplements (intake daily dose) in different amounts of distilled water (0.5,1,1.5,2 cup) were performed to obtain solutions with different concentrations (samples). The samples were examined in MRI (1.5 Tesla) using phantoms (tubes) to determine which sample had the lowest level of concentration and best quantitative and qualitative images,
The results of the in vitro study indicate that magnesium, potassium, and sodium supplements have virtually no effect on the water signal intensity in T1-weighted and T2-weighted imaging, whereas calcium supplements raise the water signal intensity on T2-weighted imaging. Manganese and iron supplements raise the water signal intensity on T1-weighted images while decreasing the water signal intensity on T2-weighted imaging, the calcium, manganese, and iron were then evaluated by volunteers.
Thirty healthy individuals underwent MRI scanning both before and after getting a mineral supplement solution. The volunteers were divided into three groups, each with ten volunteers, the first group was given a calcium supplement, the second group was given a manganese supplement, and the third group was given an iron supplement. The MRI of volunteers are evaluated quantitively by measuring the signal intensity, signal-to-noise ratio (SNR), relative signal-to-noise ratios (RSN) and contrast (C), also they are evaluated qualitatively by the radiologist.
From the results of quantitative measurements and qualitative evaluation of MR images, it can be concluded that calcium supplementation can be used as a positive contrast agent on T2-weighted imaging. On the contrary, the manganese and iron supplements act as an excellent positive contrast agent on T1-weighted imaging and a negative contrast agent on T2-weighted imaging.