Image Evaluation in Magnetic Resonance Cholangiopancreatography

K. E. P. Pinho

, P. M. Gewehr

, A. C. Pinho

, A. M. Gusso

and C. A. Goedert

Graduate Program of Electrical and Computer Engineering (CPGEI)

from Federal University of Technology-Parana (UTFPR), Curitiba, Brazil

Departament of Electrical Engineering (DAELT), UTFPR, Curitiba, Brazil

Diagnostic Clinic (Cetac), Curitiba, Brazil

Keywords: Magnetic Resonance Cholangiopancreatography, Contrast Agent, Image Evaluation, Image J, Natural Juice.

Abstract: The objective of this study is to evaluate the image quality with two different contrast agents in MRCP

compared to medical evaluation and by using the software Image J®. Natural juices and pulps of different

types (açai liquid and powder; and blend) were selected. The selection of patients (31 women and 33 men)

was performed at Clinical Hospital, which provides general care in Curitiba city (Brazil). The application of

the MRCP protocol followed a sequence tested in healthy volunteers and for the samples described. For image

analysis, 2 radiologists participated and were identified as evaluator 1 (E1) and 2 (E2), in order to identify the

effect of the contrasts on the images. For the 6 samples tested, only 2 samples remained dark on T2 weighting,

which prevents their use as contrast agent. The evaluation of the images was performed separately for each

evaluator on different days and places, to identify an appropriate action for the contrasts (A and B). The use

of the software (Image J®) allowed a less subjective analysis of the image quality when compared to the

evaluation of radiologists and, for the examples presented, a quantitative assessment since the chosen images

were submitted to the software analysis.

1 INTRODUCTION

The acquisition of images by magnetic resonance

(MRI) has the advantage to turn easier the views of

soft tissues as well as organs of difficult access

compared to other imaging methods (e. g., X-rays and

computerized tomography). However, to obtain

quality images, it is important that they can show

areas of intense (white), weak (dark) and intermediate

(gray levels) signals (Westbrook, Roth and Talbot,

2011;

Jornada, Murata and Medeiros, 2016).

Among the types of MR image acquisitions, this

study is concerned to Magnetic Resonance

Cholangiopancreatography (MRCP). This technique

makes use of a negative contrast to identify and to

show parts of the gastrointestinal system, in particular

the images of the pancreas and gall- bladder which

are superimposed (Xiao and Zhang, 2010).

The

contrast to be used can be manufactured or

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https://orcid.org/0000-0002-4014-8072

https://orcid.org/0000-0003-0716-1002

https://orcid.org/0000-0002-5255-4844

natural.

The use of a natural contrast, as the juice of

some fruit, is more indicated since it does not cause

adverse reactions and present an image similar to a

manufactured one (Fraga et al., 2004; Pinho et al.,

2019).

juice as contrast agent must be

paramagnetic;

act as biphasic contrast (showing up

positive for T1 sequences and, negative for T2);

uniformly distributed in the digestive cavity and small

intestine;

non-toxic;

and be

affordable (Duarte,

Furtado and Marroni, 2012).

The contrast agents

should have some metals that help in identifying the

image, such as iron (Fe) and manganese (Mn).

These

can be found in juices (pineapple, açai and blueberry),

teas and specific preparations (Ghanaati et al., 2011;

Griffin, Edwards and Grant, 2012; Renzulli et al.,

2019).

Oral contrast agents in MRCP examinations must

present a low signal in weighted T2, with negative

Pinho, K., Gewehr, P., Pinho, A., Gusso, A. and Goedert, C.

Image Evaluation in Magnetic Resonance Cholangiopancreatography.

DOI: 10.5220/0008987200980105

In Proceedings of the 13th International Joint Conference on Biomedical Engineering Systems and Technologies (BIOSTEC 2020) - Volume 4: BIOSIGNALS, pages 98-105

ISBN: 978-989-758-398-8; ISSN: 2184-4305

contrast effect in the region impregnated with the

contrast (Mantau et al., 2014).

In the case of the

MRCP, it is important to eliminate the stomach

(Figure 1, arrow 1) duodenum signals (Figure 1,

arrows 2) and to facilitate the visualization of gall-

bladder (Figure 1, arrow 3), common bile (Figure 1,

arrow 4a) and pancreatic ducts region (Figure 1,

arrow 4b).

The objective of this study is to evaluate the image

quality with two different contrast agents in MRCP

compared to medical evaluation and its confirmation

by the software Image J® (Souza et al., 2014). This

software was used to verify if both contrasts could

present overall MRCP equivalent image quality.

Figure 1: MRCP image after negative oral contrast

administration. Arrows indicate: (1) the stomach region and

(2) the duodenum, both erased by contrast action, (3) the

gallbladder and (4a) the common bile duct and (4b)

pancreatic duct region.

2 MATERIALS AND METHODS

The research project was approved by UTFPR Ethics

Committee (number 02.520.512.0.0000.5547.

The selection of patients (31 women and 33 men)

was performed at the Clinical Hospital of the Federal

University of Paraná (UFPR), which provides general

care in Curitiba city (Brazil).

The patients were

selected from

the

outpatient clinics of liver and fat

correlated diseases of the Hospital. Experiments were

produced to select the juice and MRCP exams were

performed in a Diagnostic Clinic of Curitiba city.

2.1 MRCP Protocol

2.1.1 Experiments with Phantom

Initially, natural juices and pulps of different types

(açai

liquid and powder; and blend) were selected.

Afterwards, they were placed in a water container, as

shown in Figure 2, and tested on a 1.5T MRI system

from General Electric Company (GE), model HDXT

with 12 channels, GE Healthcare Advantage

workstation running Centricity DICOM Viewer

version 3.0 software in the Clinic above. The protocol

determination of the samples was the same as that

used by the clinic for the examination of MRCP.

Initially: localizer (LOC) in 3 orthogonal planes (PL)

following Single-Shot (SS), Fast Spin Echo (FSE) in

apnea (LOC 3 PL SSFSE Apnea); radial cholangio

and axial lava T1 without fat (Pinho et al., 2014;

Pinho et al., 2018).

The parameters of the T1 weighting protocol

were: LAVA TR/TE 4.2/2.0 ms; FOV: 36x32 mm;

320x160; slice thickness: 4.0 mm and 0.70 NEX;

inversion time (TI): 7.0 ms. For T2: acquisition in

Fast Imaging Employing Steady-State

(Fiesta)/TR/TE 4.4/2.0 ms; FOV: 36x36 mm;

224x320; slice thickness: 3.0 mm; 1.0 NEX:

inversion time: 200 ms (Westbrook, 2010; Pinho et

al., 2018).

Figure 2: T2 sequence of image of açai samples and

commercial contrast. Identification was performed from

left to right, with numbers 1, 2 and 3 above, and 4, 5 and 6

below.

The phantom tests were carried out with six

samples of açai juice of different brands and with

different water concentrations. Figure 2 illustrates

these samples, which can be identified as follows,

respectively:

4 a

4 b

1 2

Image Evaluation in Magnetic Resonance Cholangiopancreatography

1- Açai 100 g /100 mL of water;

2- Açai powder with 13 g /100 mL of water;

3- Commercial contrast;

4- Açai frozen with 100 g /100 mL of water;

5- Açai more concentrated, 100 g/80 mL of water;

6- Açai powder with 6g /100 mL of water.

2.1.2 Experiments with Patients

The MRCP examination protocol was the same as for

the samples of juices described above, besides the

acquisition of multiple thin slices in the coronal plane

for this work: Half Acquisition Single Shot Turbo

Echo (HASTE), Turbo Spin Echo (TSE), following

thick radial cuts in FSE/TSE also with strong

weighting in T2. Here the cutting plan is directed to

the distal common bile duct.

The acquisitions were

made in Axial 2D FIESTA (with fat saturation) Array

Spatial Sensitivity Encoding Technique (ASSET)

and the radial cholangio sequence for two days of

tests, in order to compare the effectiveness of

contrasts (Sanchez et al., 2009; Pinho et al., 2018).

Each patient was identified by the respective

gender after a cardinal number (female, male), e.g.:

F1, M2 to facilitate image acquisition and storage.

The application of the MRCP protocol followed a

sequence tested in healthy volunteers. In addition,

doctors were available to perform MRCP exams in

that clinic. Since the patients would need the

examination report, on the first day a commercial

contrast (labeled A) was administered with a total

abdominal sequence and administration. On the

second day the natural contrast of açai juice (labeled

as B) was administered, and after the sequence of

MRCP was started. The dose of each contrast was 200

mL divided into 2 portions of 100 mL, one dose was

given after the anamnesis and another 10 minutes

later (Pinho et al., 2018).

2.2 Image Evaluation

For image analysis, 2 radiologists participated and

were identified (this study) as evaluator 1 (E1) and 2

(E2), both with experience in the field of diagnostic

imaging, in order to identify the effect of the contrasts

on the images.

After the exams were completed, the images were

saved in the PACS (Picture Archiving and

Communication System) (Marques et al., 2005)

system and available on file so that each evaluator

could access and analyze the effects of the contrasts

(commercial and natural), according to the scale from

1 to 4. By observing the regions of interest for

examining MRCP, i.e,. the oral contrast should erase

the sign of the stomach and duodenum. Score 1 means

that there is a hyperintensity signal of stomach and

duodenum and it is not possible to evaluate these

structures.

Score 2: assessment occurs when there is

a partial view of the structures.

In score 3,

hyperintensity signal does not hinder the analysis of

the structures, and score 4 means that there is no

signal hyperintensity for stomach and duodenum,

which makes clearer the MRCP image (Duarte,

Furtado and Marroni, 2012; Pinho et al., 2019).

Image J® software

(obtained free from

http://imagej.nih.gov

) was employed to analyze and

compare the image quality of the patients by

separating a common bile duct region, with

the same

dimension (selection rectangle with size

approximately 97.85 mm x 2.58 mm (length and

height)), in Figures 4, 5, 6 e 7. The chosen sections of

the Figures were selected by the radiologists and used

later for the Image

J® estimation of gray levels since

those regions are used for medical evaluation in order

to detect physiological alteration or correlated

diseases. For the construction of the figures with

Image

J®, the length corresponds to the anatomical

region of interest and the value to gray levels

(intensity pixels).

For that, it was chosen among the

assessed medical images, which ones

showed

a coincidence between the two MRCP

sequences for the two contrasts, and about same

scores provided by the evaluators (Brianezi, Camargo

and Miot, 2009; Pinho et al., 2019).

3 RESULTS

3.1 Experiments with Phantom

For the 6 samples tested, only 2 (sample 2 of açai

powder and 5 of açai more concentrated) remained

dark on T2 weighting, which prevents their use as

contrast agent. It is observed that in the T2 sequence

presented, the dark images of the juices and mixtures

provided the details required in the MRCP

examination, since for the bile and pancreatic images

acquisition, the administered contrast must eliminate

the residual signal.

The images of açai samples taken from Figure 2

were handled and their Regions of Interest (ROI)

values were measured. The best samples were 1, 3, 4

and 6 for T1 and T2 weighting, as seen in Figure 3.

ROI values of T1 weighting should be as great as

possible, and the values obtained were ≥ 1038

(samples 1, 3, 4 and 6). The value of 527.6 of

substance 3 is not compatible in T2 since it was low

BIOSIGNALS 2020 - 13th International Conference on Bio-inspired Systems and Signal Processing

100

compared to the others. Also in Figure 2 for T2, ROI

values of the samples must be higher because the

expected behavior is present in the image (darker),

and the amounts obtained were 1037.7 (sample 1);

527.6 (2); 1111.8 (3); 1435.1 (4); 419.4 (5) and 1188.

2 (sample 6).

The best samples for T2 were 1, 3, 4 and 6. It was

decided to use the sample 1 for ease of acquisition and

availability.

3.2 Patients and Image Analysis

The application of the MRCP protocol for 64 patients

produced 12 acquisitions were obtained with contrast

A as well as 12 with contrast B (1x12x12=144 MRCP

images). In order to present the analysis method using

Image J® to compare the images and, considering the

individual characteristics of patients, quantity and

complexity of information provided by the number of

images for each patient on 2 days of exams, it was

decided to present the results for 2 patients (M43 and

M5). One case is considered more complex and the

other is simple, but both need the action of the

contrasts to show the organs and/or to observe

existent diseases when pertinent and thus proving that

Image J® can be used for all practical cases.

Image Evaluation

The evaluation of the images was performed

separately for each evaluator on different days and

places; they have chosen within the MRCP sequence

two images to identify an appropriate action for the

contrasts (A and B), one for each type of contrast.

Figure 3 shows an image acquired with contrast A

and, Figure 4 an image acquired with contrast B for

the radial cholangio sequence of patient M43. Both

images had scores 3 from evaluators E1 and E2 on 2

days. The medical report for patient M43 described a

small ascites in the hepatic region (more visible in

Figure 3, arrow 1), chronic liver disease, distended

gallbladder and with thickened walls, with better

anatomic view in Figure 4 (arrow 2).

It is noted that on the two images (Figure 3 and 4)

there was reduced signals from the stomach and

duodenum, showing the complete bile duct. The

Figures above have shown adequate white levels

(gallbladder region, arrows 2 and, common bile duct,

arrows 3) and dark levels for stomach and duodenum

(Figure 1, arrows 1 and 2), as must be present for a

quality medical report of MRCP.

Figure 5 shows an image acquired with contrast A

and, Figure 6 an image acquired with contrast B for

the radial cholangio sequence of patient M5. Both

images had scores 3 from evaluators E1 and E2 on

first day for contrast A. On second day, considering

contrast B, E1 assigned score 3 and, E2 score 4. The

medical report described that fat liver and the other

organs (gallbladder, pancreas and ducts) were with

normal anatomic aspect.

Figure 3: Image from patient M43 which had a score 3 with

contrast A. Arrows indicate: (1) ascites region; (2)

gallbladder; (3) common bile duct. The rectangle indicates

the area of the common bile duct, chosen for the software

Image J®.

The Figures 5 and 6 have shown both contrast

with pretty similar images for MRCP, exception for

organs without interest as kidney and large intestine.

The images (Figures 5 and 6) show adequate white

levels (gallbladder region, arrows 2 and, common bile

duct, arrows 3). Particularly for Figure 5 (arrow 1),

the stomach region presented some points with white

levels where it should be dark.

The software Image J® was applied to Figures 3, 4, 5

and 6 generating a quantitative analysis of a selected

section of the common bile duct, close to the

duodenum. The arrows indicate the selected areas of

approximately 97.85 mm x 2.58 mm. The areas were

taken to build the curves of Figures 7 and 8 which

show the gray levels (pixels) as a function of distance

(width duct) for contrasts A and B. For both Figures

(7 and 8), arrows (1) indicate the duodenum and

gallbladder region, arrows (2) the common bile duct,

arrows (3) the pancreatic duct and, arrows (4) the

pancreas region.

Figure 7 shows curves as obtained with data from

Figures 3 and 4 and the software Image J®. For

regions (1) e (2) a peak value with gray levels (600.8)

Image Evaluation in Magnetic Resonance Cholangiopancreatography

101

Figure 4: Image from patient M43 which had a score 3 with

contrast B. Arrows indicate: (1) ascites region; (2)

gallbladder; (3) common bile duct. The rectangle indicates

the area of the common bile duct, chosen for the software

Image J.

Figure 5: Image from patient M5 which had a score 3 with

contrast A. Arrows indicate: (1) duodenum region; (2)

gallbladder; (3) common bile duct. The rectangle indicates

the area of the common bile duct, chosen for the software

Image J®.

was obtained at position 11.6, due to the presence of

ascites around the gallbladder (see Figure 3,

rectangle) as obtained with contrast A. Considering

the same region for contrast B, the values were quite

different. For region (3) the peak values were 365.5

(contrast A) and 284.5 (contrast B) close to point

50.3. For points from 0 to 46.4 (regions 1 and 2), a

correlation coefficient of 0.13 was calculated for the

Figure 6: Image from patient M5 which had a score 3 with

contrast B (E1) and score 4 (E2). Arrows indicate: (1)

duodenum region; (2) gallbladder; (3) common bile duct.

The rectangle indicates the area of the common bile duct,

chosen for the software Image J®.

gray levels of both contrasts. This is related to ascites

which caused some blanching over the image (Figure

4 arrow 1).

The average intensities of the same points for

contrast A was 316.6 and 113 for contrast B.

Considering region (3) which is important for an

MRCP medical report, the correlation between gray

levels was 0.95 among points from 46.4 to 54.1. The

average values for this region were 216.1 for contrast

A and, 166.4 for contrast B.

Figure 8 shows the curves as obtained with data

from Figures 5 and 6 and the software Image J®. It

shows (Figure 8) great similarity between curves for

contrasts A and B. The correlation coefficient among

all points (0 to 100) for gray levels was 0.92. The

average gray levels for points (0 to 46.4) were 32.2

and 35.7 for contrasts A and B, respectively. Taking

regions (2) and (3) from points 47.4 up to 60.6mm,

the average intensity for contrast A was 80.7 and 74.8

for contrast B.

4 DISCUSSION

The ROI values obtained for the açai samples showed

that for T2 with the higher values, they can be used as

contrast agent in MRCP, according to other authors

(Fraga et al., 2004; Espinosa et al., 2006 and Pinho et

al., 2019). Note that the açai value (sample 1) was

close to the commercial contrast (sample 3).

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Two radiologists evaluated the images obtained in

MRCP exams giving notes from 1 to 4. Two MRCP

examples were selected (patient M43 e M5) to

produce a quantitative analysis employing Image J®.

For the example (M43) presented, the images

received the same notes (3) from both evaluators,

using the commercial contrast (A) and açai juice (B).

For case M5, both images had scores 3 from

evaluators E1 and E2 on 1

day for contrast A. On 2

day, considering contrast B, E1 assigned score 3 and,

E2 score 4.

The chosen images, by both evaluators for M43

patient, are equal within the MRCP sequences.

Considering Figure 3, the gallbladder did not present

all the contours, differing from Figure 4 (where it

showed). This organ presents great motility with time

what can explain the differences between Figures 3

and 4 (arrows 2), besides the variability of food

ingestion, which alters gallbladder physiology.

For patient M43 (Figure 7), Image J® presented

gray levels with peak value of 600.8 and average

value of 316.6 for regions 1 and 2 on first day. These

values are bigger than those presented on second day.

The higher values are explained by means of Figure 3

since the ascites was more visible. The correlation

coefficient between contrasts curves was pretty low

for regions 1 and 2 due to the high variability of

ascites viewing. Taking only region 3, the correlation

is very high (0.95), what shows that both contrasts are

acting very well within the common bile duct.

Taking Figure 8 (Image J®) for M5 patient, there

were clean regions showing the common bile duct,

with gray average intensity of 32.2 (contrast A) for

region 1 (duodenum and gallbladder) and 35.7

(contrast B). For regions 2 and 3, which are important

to find out anatomical alteration or diseases, average

intensity was 80.7 (contrast A) and 74.8 (contrast B)

meaning that both contrasts had similar values and

clear views of the common bile and pancreatic ducts

regions, as expected for an oral negative contrast.

Also, evaluators noticed no difference between

contrasts.

The limitations of the work are related to the fact

that there is no known association between the

artifacts present in the image and the evaluators'

grades. Artifacts can be from the equipment (lack of

quality control) and/or from the patient.

The artifacts

from the patient may be due to illness, lack of

adequate preparation for the exam, physiological

changes and others. These modify the image quality,

as well as the note of the evaluator.

Image J® software showed for the cases

described, the one with presence of diseases there was

increase of average gray level (patient M43) for

ascites (about 113), while for patient M5 (normal

MRCP) the average was low (about 36).

5 CONCLUSIONS

The present study aimed to evaluate the image quality

with two different contrast agents (commercial and

Figure 7: Plots of the selected regions of radial cholangio images from the common bile duct of patient M43 as obtained with

the software Image J® The curves represent the gray levels against distance for contrasts A and B. Arrows indicate: (1)

duodenum region and gallbladder; (2) near common bile duct; (3) common bile duct and, (4) pancreas body.

100

200

300

400

500

600

0 102030405060708090100

Gray levels

Width distance (mm)

Contrast A

Contrast B

Image Evaluation in Magnetic Resonance Cholangiopancreatography

103

Figure 8: Plots of the selected regions of radial cholangio images from the common bile duct of patient M5 as obtained with

the software Image J®. The curves represent the gray levels against distance for contrasts A and B. Arrows indicate: (1)

duodenum region and gallbladder; (2) common bile duct; (3) pancreatic duct and, (4) pancreas body.

natural) in MRCP compared to medical evaluation

and confirmation by the software Image J®.

The natural contrast (açai) was able to erase the

signal from the stomach and duodenum (as shown),

as well as enhanced signal to the common bile duct,

as it should be in the clinic for a quality image in

MRCP.

The use of the software (Image J®) allowed a less

subjective analysis of the image quality when

compared to the evaluation of radiologists and, for the

examples presented (patients M43 and M5), a

quantitative assessment since the chosen images were

submitted to the software analysis. Thus, the gray

levels intensities obtained with the software Image J®

corroborates the view of the evaluators E1 and E2

with the images. Anyhow, the results open an

excellent opportunity for further studies, to establish

an automated protocol that uses available software

since it was useful to confirm the existence or not of

anatomical alteration and/or diseases.

ACKNOWLEDGEMENTS

To Araucaria Foundation from Parana State, for

providing research support through project number

355/2012.

To Clinics Hospital-UFPR and, Curitiba

Diagnostic Clinic, where this work was carried out.

REFERENCES

Brianezi, G., Camargo, J.L.V., Miot, H.A., 2009.

Development and validation of a quantitative image

analysis method to evaluate comet assay (silver

staining). J Bras Patol Med Lab.; 45 (4): 325-34.

Duarte, J.A., Furtado, A.P.A., Marroni, C.A., 2012. Use of

pineapple juice with gadopentetate dimeglumine as a

negative oral contrast for magnetic resonance

cholangiopancreatography: a multicentric study.

Abdominal Imaging; 37: 447- 56

Espinosa, M.G., Sosa, M., Rodríguez, L.M. De L.,

Córdova, T., Alvarado, J.B., Rodríguez, M.A.,

Aguilera, J.A.R., 2006. Blackberry (Rubus spp.): a pH-

dependent oral contrast medium for gastrointestinal

tract images by magnetic resonance imaging. Magnetic

Resonance Imaging; 24 195–200.

Fraga, T.C., Araujo, D.B., Sanchez, T.A., Elias, J.Jr.,

Carneiro, A.A.O., Oliveira R.B., Sosa, M., Baffa, O.,

2004. Euterpe olerácea (açaí) as an alternative oral

contrast agent in mri of the gastrointestinal system:

preliminar results. Magnetic Resonance Imaging.; 22;

389-93.

Ghanaati, H., Yazdi, H.R., Jallati, A.H., Abahashemi, F.,

Shakiba, M., Firouznia, K. 2011.Improvent of MR

cholangiopancreatography (MRCP) images after black

tea consumption. European Radiology, 21; 2551-57.

Griffin, N., Edwards, G.C., Grant, L.A., 2012. Magnetic

Resonance Cholangiopancreatography: the ABC of

MRCP. Insights Imaging; 3:11-21.

Image J. Online. http://imagej.nih.gov. Acessed 12

October. 2019.

Jornada, T.S., Murata, C.H., Medeiros, R.B., 2016.

Influence of partial k-space filing on the quality of

100

150

200

250

300

0 102030405060708090100

Gray levels

Width distance (mm)

Contrast A

Contrast B

BIOSIGNALS 2020 - 13th International Conference on Bio-inspired Systems and Signal Processing

104

magnetic resonance images. Radiologia Brasileira ; 49

(3): 158- 64.

Marques, P.M.A., Caritá, E.C., Benedicto, A.A., Sanches,

P.R.,

2005. Integração RIS/PACS no Hospital das

Clínicas de Ribeirão Preto: uma solução baseada em “

web”. Radiologia Brasileira; 38 (1): 37- 43.

Mantau, J.N., Pinho, K.E.P., Costa, R.Z.V., Pinho, A.C.

Estudo comparativo do contraste negativo e contraste

natural em exame de colangiopancreatografia por

ressonância magnética. In: 44ª Jornada Paulista de

Radiologia [internet]. 2014, São Paulo, Painel

Impresso: Abdominal/Gastrointestinal. Available from:

˂http://static.spr.org.br/jpr/2014/trabalhosapresentados

/#modal-trabalho pdf˃

Pinho, K.E.P., Pinho, A.C., Gewehr, P.M., Gusso, A.M.

Image Quality in Magnetic Resonance Cholangi-

pancretography Exams: Study Between Açai Juice

and Manufactured Contrast Agent. In: Costa-Felix

R., Machado J., Alvarenga A. (eds) XXVI Brazilian

Congresso n Biomedical Engineering, 2018 IFMBE

Proceedings, 70/2. Springer, Singapore, Avaliable

from:˂ https://link.springer.com/chapter/10.1007/978-

981-13-2517-5_40˃ Acessed 24/10/2019

Pinho, K.E.P., Pinho, A.C., Pisani, J.C., Goedert, C. A.;

Magri, A.G., Gewehr, P.M. 2019.Açai juice as contrast

agent in MRCP exams: qualitative and quantitative

image evaluation. Brazilian Archives of Biology and

Technology .62 (e19160697), 1-14.

Pinho, K.E.P., Gewehr, P.M., Pinho, A.C., Pisani, J.C.

Sucos naturais como agentes de contraste para exames

de colangiopancreatografia por ressonância magnética.

In: XXIV Congresso de Engenharia

Biomédica[internet]. 2014; p. 1685-1688. Available

from:˂http://www.canal6.com.br/cbeb/2014/artigos/cb

eb2014_submission_499.pdf˃

Renzulli, M.; Biselli, M.; Fabbri, E.; Caretti, D.; Sergenti,

A.; Modestino, F.; Giannone, F.A.; Storchi, M.;

Pierotti, L.; Golfieri, R. 2019. What is the best fruit

juice to use a negative oral contrast agent in magnetic

resonance cholangiopancreatography? Clinical

Radiology, 74; 220-227.

Souza, V.B., Federizzi, M., Fernandes, D., Franco, A.R.:

Avaliação quantitativa da qualidade de exame de

imagem por ressonância magnética nuclear. In: XXIV

Congresso Brasileiro de Engenharia Biomédica

[internet]. 2014. Available from: http://www.canal6.

com.br/cbeb/2014/artigos/cbeb2014_submission_375.

pdf

Sanchez, T.A., Elias, J.Jr., Colnago, L.A., Troncon, L.E.A.,

Oliveira, R.B., Baffa, O., Araujo, D.B., 2009. Clinical

Feasibility of açaí (Euterpe olerácea) pulp as an oral

contrast agent for magnetic resonance

cholangiopancreatography. Journal of Computer

Assisted Tomography; 23(5), 666-70.

Xiao, B., Zhang, X.M., 2010. Magnetic resonance imaging

for acute pancreatitis. World Journal of Radiology;

August 28; 2(8): 298-308.

Westbrook, C., Roth, C.K.; Talbot, J.,2011. MRI in

Practice. 4

. Wiley Black Well.

Westbrook, C., 2010. Manual de Técnicas de Ressonância

Magnética. 3

ed. Rio de Janeiro: Guanabara Koogan.

Image Evaluation in Magnetic Resonance Cholangiopancreatography

105