This works aims to
administration of açai
juice as compared to
17 standard iron oxide based contrast employed as
negative oral contrast agents in Magnetic Resonance
19 Cholangiopancreatography (MRCP), employing qualitative and quantitative evaluation. The research
20 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 to
23 patients. 2 radiologists (R1 and R2) evaluated the images, classifying them by a score (maximum of 4). In order to
24 have a quantitative assessment, Image J free software was employed generating plots of gray levels against distance
26 of a chosen area of the bile duct interest region. Evaluating images for contrast A, R1 furnished an average score of
27 3.52 and R2 of 3.27. For contrast B, R1 provided 3.44 and R2 3.38. Both evaluators considered image quality with
28 contrast A adequate for 62 (96.9%) patients. R1 considered adequate for 62 (96.9%) and R2 for 60 (93.8%) patients
30 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
A and B. Thus, açai
32 alternative as contrast agent in MRCP, since a standardized protocol is implemented.
Image J was employed as a
34 new method for quantitative investigation of image quality, presenting good agreement with medical opinion.
36 Key words:
oxide contrast; magnetic resonance cholangiopancreatography; image
38 quality; image J.
42 Magnetic Resonance Cholangiopancreatography (MRCP) exams
43 identify and visualize organs such as pancreas and gallbladder. In the images, contrast agents can avoid
44 the overlapping of these organs 1. The procedure is useful for detection of pancreatitis,
46 biliary sludge, pseudo pancreatic cysts, tumors and others. Images acquired by magnetic resonance with
47 natural contrasts are very similar to those acquired with manufactured ones, according to previous work
48 done by other authors 2.
49 For a juice to be effective as contrast agent in MRCP exams, some features are required 3, besides acting
50 to reduce
intensity from the stomach and duodenum
51 views. Although there are papers about the use of juices as MRCP contrast agents 4, it was not found
52 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 or
54 using some computational tool 7, 8, 9. These can help to identify lesions, tumors or some kind of alteration
55 of the organ
56 technique employed or analysis made by different personnel and equipment.
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5 Since there is a great amount of subjectivity on the assessment of the acquired images by medical teams,
on the previous experience
of each evaluator,
there is an opportunity
to explore the use of
7 Image J free software 10 in order to produce a new quantitative analysis of the images and to compare
8 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 as
10 negative oral contrast agents, by means of medical evaluation and with the use of Image J software 10.
14 Contrast agents
its use on previous works, a natural juice obtained from açai (Euterpe oleracea) pulp was
17 employed as contrast agent, containing approximately 36 grams of carbohydrates per 100g, corresponding
18 to the amount of sugar in the fruit 11. The manufactured
iron oxide based contrast was obtained from
19 Guerbet Ltda and used as specified for MCRP exams.
21 MRCP exam protocol
23 As patients
(first day) after the ingestion of the
iron oxide based contrast (referred as A) with the sequence of full abdomen, followed by
25 MRCP. On the second day, after the ingestion of açai juice (referred as contrast B), the MRCP sequence
26 was also
Doctors supported the patients in
exams, but the type of
27 administered each day was kept secret.
Thus, the study was double-blind and prospective 12.
29 The images were acquired with a 1.5T MRI system from General Electric Company (GE), model HDXT
30 with 12 channels, GE Healthcare
Advantage workstation running Centricity DICOM
31 and Communications in Medicine) Viewer version 3.0 software, and were saved in the filing system and
32 communicating images (PACS-Picture Archiving and Communication System) 13,
in a clinic of Curitiba
33 city (Brazil). The usual MRCP acquisition protocol was used: localizer (LOC) in 3 orthogonal planes
34 (PL) following single-shot (SS), fast spin echo (FSE) in apnea (LOC 3 PL SSFSE Apnea); radial colangio
35 14 and axial lava T1 without fat 15 for the two days of exams.
37 Patient selection
39 The selection of patients was made at the Clinics Hospital of Parana Federal University (UFPR), which
40 receives patients from the metropolitan
region of Curitiba city (via Health Units). The clinical research
41 was developed during
a period of
in the outpatient clinics
liver disease and fat and
The study was
43 Committee of Federal University of Technology-Paraná (UTFPR) by number 02.520.512.0.00005547 and
44 a free and informed consent form (ICF) was released. Patients who agreed to participate received the ICF
45 and appropriate guidance on the MRI examination.
47 For patient preparation,
it was determined
3 hours of absolute fast. On the first day, when the patient
48 arrived at the clinic, he/she was directed to the preparation room, the fasting time was confirmed and the
contrast (A) was fractionated in 2 doses of 100 mL, one dose was given after the patient
50 responded the anamnesis, and
another was given 10
minutes later. The anamnesis
51 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 after
53 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.
56 Patients who participated met the following criteria: age between 18 and 80 years for both genders, need
57 to perform exams of MRCP and present pancreaticobiliary
disease and/or alteration in liver ducts 16, 17
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Archives of Biology and Technology
treatment or follow-up
referred hospital and,
6 accomplish fasting of 3 hours in the 2 days of the exams.
Also, patients should
7 claustrophobia nor hearing difficulties.
9 Exclusion criteria
who could not ingest juice and/or contrast agent, or
10 difficulty as: not being able to perform fasting, making use of devices such as pacemakers, aneurysm
11 clips, stents, intraocular
cochlear implants, prosthetic/ pins in any region of the body
12 which could cause artifacts 18. Also, exclusion criteria included pregnancy or suspected pregnancy.
14 Medical images analysis
16 For the analysis of images, there was the collaboration
of 2 radiologists
identified as R1 and R2, both
17 with large experience in image diagnosis of more than 13 years.
19 To analyze the effects of contrasts, scores 1-4 were used, having as reference the action of the contrast in
20 places where it must make effect (stomach and duodenum). Score 1 means that there is a hyper intensity
21 of the stomach and
thus it is not possible to
22 evaluation takes place partly when it is possible to visualize the structures. Score 3: the hyper intensity of
23 the signal does not hinder the analysis of structures. Score 4: there is no signal hyper intensity between
24 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 which
classification for contrasts A and B as excellent, good, fair and poor; if the
27 acquired image for contrasts A and B could replace each other; and if the contrasts were suitable and
28 efficient for issuing a medical report 19.
29 Also, a new
30 employed 9 and it can furnish the intensity of pixels against distance of a chosen area of an image. By
31 taking a section of interest from the image, one can limit the anatomical region of the structure to be
After, the selected
area (with x and y values) is transferred
to an Excel®
file and a plot is
33 produced with gray levels (pixel intensities) against distance (width of the bile duct region for this study)
34 in mm 20.
37 Statistical analysis
39 Data analysis of patients was performed with the items in the anamnesis and medical evaluations, in order
40 to assist in verifying the behavior of the variables 21. Subsequently, it was evaluated the concordance of
41 responses of doctors through Kappa 22 statistics, aimed at testing the degree of concordance (reliability
42 and precision), and to assess the values obtained. If ? 0.75, it indicates an excellent result. Values ? 0.40
43 are considered low or if they become between 0.40 and 0.75 are of median concordance 23.