Evaluating the Clinical Application Value of Ferric Citrate Effervescent Granules (FAC) in Magnetic Resonance Cholangio-Pancreatography (MRCP) Inspection

Objective: Assessing the clinical application value of Ferric Citrate Effervescent granules (FAC) in magnetic resonance cholangio-pancreatography (MRCP) inspection. Methods: We invited 10 patients who were diagnosed with diseases of the pancreas system and bile duct system and undergoing magnetic resonance cholangio-pancreatography and use Ferric Citrate Effervescent granules in the MRCP process. The time of their MRCP is from May 2018 to February 2020. In addition, we collected the information from the participants, that the information included Sequence and scanning parameters of Mr Cholangiopancreatography, Image quality score before and after MRCP administration, contrast to noise ratio (CNR) score and comparison score of different parts in MRCP images before and after drug administration. Result: In scanning parameters, the data is standard in research, that the TR and TE of 2d MRCP and 3D MRCP are similar, that are > 6000 and > 500. But Layer thickness/Layer spacing between the objects had big gap in data, that are 50/0 and 1.8/0. Additionally, FOV had little different length, which is 40 vs 36. In NEX, they are same. In image quality score, it has higher score after taking the FAC. The CNR score research is similar, that FAC affect the CNR outcome. Conclusion: the FAC provide the improvement to the outcome of patient in MRCP process, that it improves image quality of MRCP.


Introduction
In medical imaging, the magnetic resonance cholangio-pancreatography (MRCP) is common detection method. Base on the research, MRCP is a noninvasive imaging technique, that it is often used to establish role in demonstrating biliary tract anatomy and in providing a roadmap for interventional treatments [1][2][3]. As the development of science and technology in medical electronics, the quality of the MRCP images was improved by many three-dimensional (3D) sequences. In 3D MRCP, it uses a maximum intensity projection or volume rendered technique for accurate display of the biliary tree and pancreatic duct [4][5][6]. In limitation, as the adoption of heavy T2 weighted MRCP imaging, images of gastrointestinal fluid often overlap with the pancreatic bile duct when doctor use MRCP to test the patient. As a result, the bile ducts of the pancreas are not clearly visible [7]. However, during MRCP examination, simultaneous development of gastric and intestinal fluids showed high signals, which interfered with the display of biliary and pancreatic ducts. In Chinese hospital, the doctor often uses ferric ammonium citrate granules (FAC) to improve image quality of MRCP [15,17].
Ferric ammonium citrate granules are commonly used as blood tonic in clinic to treat iron deficiency anemia [8]. It is mainly composed of iron, ammonium and citric acid, and varies with different synthetic conditions, so there is no accurate chemical formula. Meanwhile, ammonium ferric citrate has long been studied and used as a water-soluble positive contrast agent [9]. The active component which contains 5 unpaired spintronic paramagnetic iron elements, and its characteristics can reduce the T2 value of gastric and duodenal fluid shortening, thus reducing the interference background caused by its high signal [10]. The aim of this study is evaluating the clinical application value of Ferric Citrate Effervescent granules (FAC) in magnetic resonance cholangio-pancreatography (MRCP) inspection.

Participants Enrollment and Survey Methods
We invited 10 patients who were diagnosed with diseases of the pancreas system and bile duct system and undergoing magnetic resonance cholangio-pancreatography and use Ferric Citrate Effervescent granules in the MRCP process. The time of their MRCP is from May 2018 to February 2020. All participants had been signed informed consent before this research beginning. In addition, we collected the information from the participants, that the information included Sequence and scanning parameters of Mr Cholangiopancreatography, Image quality score before and after MRCP administration, CNR score and comparison score of different parts in MRCP images before and after drug administration.
By two with one high qualification doctor before and after oral FAC image quality assessment rating: MRCP I level: a large patch of high signal within the gastrointestinal tract shadow liquid artifact is serious, affect the diagnosis (1); II part of the gastrointestinal fluid artifact implications to the diagnosis (2 points); Ⅲ level: there are a few gastrointestinal fluid artifact, but will not affect the diagnosis (3 points); Ⅳ, completely inhibited gastrointestinal fluid signal (4 points). Add the scores of the two reviewers and divide by 2 as the final score Their inclusion criteria were: (1) The patient successfully complete the MRCP (2) Patients volunteered to participate in research. (3) They did not suffer from other severe complications. Their withdraw criteria were: (1) Poor mental health (2) Changing hospital during investigation.

Statistical Analysis
Our data analyzer performed the statistical analysis by SPSS 22.0. The P value, t-test and chi-square test were associated with collection result were analyzed.

Result
In sequence and scanning parameters of Mr cholangiopancreatography, the data include TR (ms), TE (ms), layer thickness/Layer spacing (mm), FOV (cm) and NEX ( Table 1). The TR and TE of 2d MRCP and 3D MRCP are similar, that are > 6000 and > 500. But Layer thickness/Layer spacing between the objects had big gap in data, that are 50/0 and 1.8/0. Additionally, FOV had little different length, which is 40 vs 36. In NEX, they are same. In image quality score before and after MRCP administration, it contains two parts that are 2D MRCP and 3DMRCP. In the part it has the before taking the medicine step and the after taking the medicine step. In between two steps, the after taking the medicine step has higher score. In between two parts, II level has higher score in research ( Table 2). In Table 3, it indicated contrast to noise ratio (CNR) score of different parts in before and after taking the medicine. In after taking the medicine research, it has better performance than that of before taking the medicine (FAC). In the result, the bottom of stomach has biggest changing between before using the FAC and after using the FAC (from 211.39±103.60 to 81.75±98.07). Additionally, only duodenum and right hepatic duct are statistical significance in the research result (P < 0.05)

Discussion
The medical imaging, the magnetic resonance cholangio-pancreatography is defined that is a non-invasive, safe and effective cholangiopancreatography technique that uses the heavy T2-weighted technique to present high signals in the anatomical structure of the pancreatic bile duct containing bile and pancreatic fluid, and no contrast agent is used in the imaging process [11][12][13]. It is a non-invasive, safe and effective cholangiopancreatography technique [14]. In 2D-MRCP, its thick collection sequence through single level, without post-processing gain levels within the system volume of pancreatic MRCP projection images, often in a breath breathless cases at the end of the collection. Although the clinical commonly used 2D-MRCP, 3D-MRCP sequence is also a kind of method cannot be ignored, it is a way of 3 d acquisition, collect data by thin layer scanning, and the post-processing can be directly from different angles show the anatomical structure of the system of pancreatic [15,16].
According to the results above, the FAC provide the improvement to the outcome of patient in MRCP process, that it improves image quality of MRCP. In Table 2, it indicated FAC increase the image quality score in 2D MRCP group and 3D MRCP group, that FAC improve the image quality so that the MRCP effect is improved. In addition, CNR scores are decreased after FAC administration, it indicated FAC can affect the CNR in different body parts. But only duodenum and right hepatic duct are statistical significance in the research result (P < 0.05). In limitation, CNR was decreased in all parts, but only in the stomach and duodenum was statistically significant in this paper, which may be related to the small number of samples, which should be further examined after the sample size was enlarged. In addition, the sample size also is a limitation in this study, that most CNR score are not statistical significance in the result as samples are too less.

Conclusion
In conclusion, the FAC provide the improvement to the outcome of patient in MRCP process, that it improves image quality of MRCP. In study result, image quality score had higher score after taking the FAC. In addition, the FAC only action on the he bottom of stomach, duodenum and right hepatic duct as their CNR score are statistical significance. However, CNR was decreased in all parts, but only in the stomach and duodenum was statistically significant in this paper, which may be related to the small number of samples, which should be further examined after the sample size was enlarged.