This works aims to assess images obtained with administration of açai juice as compared to a manufactured17 standard iron oxide based contrast employed as negative oral contrast agents in Magnetic Resonance1819 Cholangiopancreatography (MRCP), employing qualitative and quantitative evaluation. The research was20 developed with 64 patients submitted to MRCP exams (on 2 days) in a clinic of Curitiba city (Brazil). On the 1st day,21 a manufactured iron oxide based contrast (A) was offered and on the 2nd day, açai juice (contrast B) was given to2223 patients. 2 radiologists (R1 and R2) evaluated the images, classifying them by a score (maximum of 4). In order to24 have a quantitative assessment, Image J free software was employed generating plots of gray levels against distance2526 of a chosen area of the bile duct interest region. Evaluating images for contrast A, R1 furnished an average score of27 3.
52 and R2 of 3.27. For contrast B, R1 provided 3.44 and R2 3.38. Both evaluators considered image quality with28 contrast A adequate for 62 (96.9%) patients. R1 considered adequate for 62 (96.
9%) and R2 for 60 (93.8%) patients2930 when using açai juice. By taking same images for all patients with Image J, a quantitative analysis was obtained,31 resulting correlation coefficient of 0.
986 between average curves of contrasts A and B. Thus, açai juice is an32 alternative as contrast agent in MRCP, since a standardized protocol is implemented. Image J was employed as a3334 new method for quantitative investigation of image quality, presenting good agreement with medical opinion.3536 Key words: Açai contrast agent; iron oxide contrast; magnetic resonance cholangiopancreatography; image3738 quality; image J.394041 INTRODUCTION42 Magnetic Resonance Cholangiopancreatography (MRCP) exams make use of a negative contrast to43 identify and visualize organs such as pancreas and gallbladder.
In the images, contrast agents can avoid 45 44 the overlapping of these organs 1. The procedure is useful for detection of pancreatitis, cholelithiasis,46 biliary sludge, pseudo pancreatic cysts, tumors and others. Images acquired by magnetic resonance with47 natural contrasts are very similar to those acquired with manufactured ones, according to previous work48 done by other authors 2.49 For a juice to be effective as contrast agent in MRCP exams, some features are required 3, besides acting50 to reduce signal intensity from the stomach and duodenum and, improving bile duct and gallbladder51 views.
Although there are papers about the use of juices as MRCP contrast agents 4, it was not found52 publications about standardization procedure and administration protocol of the juices 5, 6.53 Image evaluation is achieved from several ways in clinics and hospitals by means of medical analysis or54 using some computational tool 7, 8, 9. These can help to identify lesions, tumors or some kind of alteration55 of the organ or tissue being examined.
Image evaluation can present inherent limitation due to the 57 56 technique employed or analysis made by different personnel and equipment.BrazilianArchives of Biology and TechnologyPage2 of 13 12345 Since there is a great amount of subjectivity on the assessment of the acquired images by medical teams,6 depending on the previous experience of each evaluator, there is an opportunity to explore the use of7 Image J free software 10 in order to produce a new quantitative analysis of the images and to compare8 them to medical evaluation. Thus, the main objective of this study was to assess quality of MRCP images,9 obtained with the administration of açai juice and a manufactured iron oxide based contrast employed as10 negative oral contrast agents, by means of medical evaluation and with the use of Image J software 10.111213 MATERIALSAND METHODS14 Contrast agents1516 Considering its use on previous works, a natural juice obtained from açai (Euterpe oleracea) pulp was17 employed as contrast agent, containing approximately 36 grams of carbohydrates per 100g, corresponding18 to the amount of sugar in the fruit 11. The manufactured iron oxide based contrast was obtained from19 Guerbet Ltda and used as specified for MCRP exams.
2021 MRCP exam protocol2223 As patients would need a medical report, the exam was started (first day) after the ingestion of the24 manufactured iron oxide based contrast (referred as A) with the sequence of full abdomen, followed by25 MRCP. On the second day, after the ingestion of açai juice (referred as contrast B), the MRCP sequence26 was also performed. Doctors supported the patients in the days of exams, but the type of contrast27 administered each day was kept secret. Thus, the study was double-blind and prospective 12.2829 The images were acquired with a 1.
5T MRI system from General Electric Company (GE), model HDXT30 with 12 channels, GE Healthcare Advantage workstation running Centricity DICOM (Digital Imaging31 and Communications in Medicine) Viewer version 3.0 software, and were saved in the filing system and32 communicating images (PACS-Picture Archiving and Communication System) 13,in a clinic of Curitiba33 city (Brazil). The usual MRCP acquisition protocol was used: localizer (LOC) in 3 orthogonal planes34 (PL) following single-shot (SS), fast spin echo (FSE) in apnea (LOC 3 PL SSFSE Apnea); radial colangio35 14 and axial lava T1 without fat 15 for the two days of exams.3637 Patient selection3839 The selection of patients was made at the Clinics Hospital of Parana Federal University (UFPR), which40 receives patients from the metropolitan region of Curitiba city (via Health Units). The clinical research41 was developed during a period of 6 months, in the outpatient clinics of non-alcoholic esteatopathy,42 alcoholic liver disease and fat and biliary routes diseases. The study was approved by the Ethics43 Committee of Federal University of Technology-Paraná (UTFPR) by number 02.520.512.
0.00005547 and44 a free and informed consent form (ICF) was released. Patients who agreed to participate received the ICF45 and appropriate guidance on the MRI examination.4647 For patient preparation, it was determined 3 hours of absolute fast. On the first day, when the patient48 arrived at the clinic, he/she was directed to the preparation room, the fasting time was confirmed and the49 manufactured contrast (A) was fractionated in 2 doses of 100 mL, one dose was given after the patient50 responded the anamnesis, and another was given 10 minutes later. The anamnesis contained51 anthropometric data, history of allergy, use of medicines, pre-existing diseases (as diabetes and hepatitis),52 surgeries, etc.
In case of a diabetic patient, glucose measurement in blood was performed before and after53 ingestion of contrasts. On the second day, the procedure was similar, only changing the contrast, i. e.,54 administration of açai juice (B) in 2 doses of 100 mL was started.5556 Patients who participated met the following criteria: age between 18 and 80 years for both genders, need57 to perform exams of MRCP and present pancreaticobiliary disease and/or alteration in liver ducts 16, 17Page3 of 13BrazilianArchives of Biology and Technology 12345 being in treatment or follow-up in the referred hospital and, ingest the contrast agents orally and6 accomplish fasting of 3 hours in the 2 days of the exams. Also, patients should lie down, not have7 claustrophobia nor hearing difficulties.89 Exclusion criteria involved patients who could not ingest juice and/or contrast agent, or had some10 difficulty as: not being able to perform fasting, making use of devices such as pacemakers, aneurysm11 clips, stents, intraocular foreign bodies, cochlear implants, prosthetic/ pins in any region of the body12 which could cause artifacts 18.
Also, exclusion criteria included pregnancy or suspected pregnancy.1314 Medical images analysis15 For 16 For the analysis of images, there was the collaboration of 2 radiologists identified as R1 and R2, both17 with large experience in image diagnosis of more than 13 years.1819 To analyze the effects of contrasts, scores 1-4 were used, having as reference the action of the contrast in20 places where it must make effect (stomach and duodenum).
Score 1 means that there is a hyper intensity21 of the stomach and duodenum signals, thus it is not possible to evaluate these structures. Score 2: Review 22 evaluation takes place partly when it is possible to visualize the structures. Score 3: the hyper intensity of23 the signal does not hinder the analysis of structures. Score 4: there is no signal hyper intensity between24 the stomach and duodenum, which makes clearer the MRCP exam 8.25 The evaluation of the image quality by doctors followed the filling of a patient individual form which26 contained: image quality classification for contrasts A and B as excellent, good, fair and poor; if the27 acquired image for contrasts A and B could replace each other; and if the contrasts were suitable and28 efficient for issuing a medical report 19.
29 Also, a new quantitative evaluation method based on Image J free software, 16-bits version, was30 employed 9 and it can furnish the intensity of pixels against distance of a chosen area of an image. By31 taking a section of interest from the image, one can limit the anatomical region of the structure to be32 analyzed. After, the selected area (with x and y values) is transferred to an Excel® file and a plot is33 produced with gray levels (pixel intensities) against distance (width of the bile duct region for this study)34 in mm 20.353637 Statistical analysis3839 Data analysis of patients was performed with the items in the anamnesis and medical evaluations, in order40 to assist in verifying the behavior of the variables 21. Subsequently, it was evaluated the concordance of41 responses of doctors through Kappa 22 statistics, aimed at testing the degree of concordance (reliability42 and precision), and to assess the values obtained. If ? 0.75, it indicates an excellent result.
Values ? 0.4043 are considered low or if they become between 0.40 and 0.75 are of median concordance 23.