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Assessment of abdominal organ motion using cine magnetic resonance imaging in different gastric motilities: a comparison between fasting and postprandial states

Assessment of abdominal organ motion using cine magnetic resonance imaging in different gastric... Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 Journal of Radiation Research, Vol. 60, No. 6, 2019, pp. 837–843 doi: 10.1093/jrr/rrz054 Advance Access Publication: 24 August 2019 Assessment of abdominal organ motion using cine magnetic resonance imaging in different gastric motilities: a comparison between fasting and postprandial states 1,2, 1 3 Hotaka Nonaka , Hiroshi Onishi , Makoto Watanabe and 1,4 Vu Hong Nam Department of Radiology, University of Yamanashi, Institutional address: 1110 Shimokato, Chuo City, Yamanashi, 409-3898, Japan Department of Radiology, Fujiyoshida Municipal Hospital, Institutional address: 6530 Kamiyoshida, Fujiyoshida City Yamanashi, 403-0005, Japan Department of Radiological Technology, Fujiyoshida Municipal Hospital, Institutional address: 6530 Kamiyoshida, Fujiyoshida City Yamanashi, 403-0005, Japan Department of Oncology and Nuclear Medicine, Hospital 175, Institutional address: 786 Nguyen Kiem Street, Ward 3, Go Vap District, Ho Chi Minh City, 9856013, Viet Nam *Corresponding author. Department of Radiology, University of Yamanashi, Institutional address: 1110 Shimokato, Chuo City, Yamanashi 409-3898, Japan. Tel: +81 55 2731111; Fax: +81 55 2739766; Email: nonakahotaka@gmail.com (Received 28 December 2018; revised 24 March 2019; editorial decision 26 June 2019) ABSTRACT This study assessed abdominal organ motion induced by gastroduodenal motilities in volunteers during fasting and postprandial states, using cine magnetic resonance imaging (cine-MRI). Thirty-five volunteers underwent cine-MRI while holding their breath in the fasting and postprandial states. Gastric motility was quantified by the amplitude and velocity of antral peristaltic waves. Duodenal motility was evaluated as the change of duodenal diameter. Abdominal organ motion was measured in the liver, pancreas and kidneys. Motion was quantified by calculating maximal organ displacement in the left–right, antero–posterior and caudal–cranial directions. Median antral amplitude and velocity in the fasting and postprandial states were 7.7 and 15.1 mm (P < 0.01), and 1.3 and 2.5 mm/s (P < 0.01), respectively. Duodenal motility did not change. Median displacement for all organs ranged from 0.9 to 2.9 mm in the fasting state and from 1.0 to 2.9 mm in the postprandial state. Significant increases in abdominal organ displacement in the postprandial state were observed in the right lobe of the liver, pancreatic head and both kidneys. Differences in the median displacement of these organs between the two states were all <1 mm. Although the motion of several abdominal organs increased in the postprandial state, the difference between the two states was quite small. Thus, our study suggests that treatment planning and irradi- ation need not include strict management of gastric conditions, nor the addition of excess margins to compen- sate for differences in the intra-fractional abdominal organ motion under different gastric motilities in the fasting and postprandial states. Keywords: abdominal organ motion; gastric motility; cine magnetic resonance imaging; intra-fractional motion INTRODUCTION overall abdominal organ motion. Abdominal organ motion induced Recently, high-precision radiotherapy, such as stereotactic body radi- by respiration has been previously studied [1–3], and unreliable ation therapy or intensity modulated radiation therapy, has become tumor dose and normal tissue volume due to respiration on treat- available to treat abdominal tumors. High-precision radiotherapy ment planning computed tomography has been reported [4, 5]. requires an accurate understanding of the intra-fractional motions of Following recent technological advances, cine magnetic resonance abdominal tumors and organs. Respiration contributes greatly to imaging (cine-MRI) has been proposed to monitor gastric or © The Author(s) 2019. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. � 837 Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 � H. Nonaka et al. gastroduodenal motilities [6–11]; cine-MRI has been previously angle = 40°, slice thickness = 5 mm, matrix = 288 × 192, field of used for measurements of abdominal tumor motion that are primar- view = 360 mm). A series of 24 images of the stomach, duodenum, ily induced by respiration [12, 13]. However, there is a lack of liver, pancreas and kidneys was collected over a 20-s period. focused studies of the abdominal motion induced by gastrointestinal Breathing was held, following voice guidance, to eliminate abdom- motilities, the diet management needed to control such motion, and inal organ motion induced by respiration. the internal margins required to take this motion into account when planning irradiation treatment of these organs. To the best of our Assessment of gastroduodenal motilities and abdominal knowledge, this is the first study of the relationship between intra- organ displacements fractional abdominal organ motions, and gastroduodenal motilities. Each series of images was measured using a 3D image analysis sys- The aim of this study was to determine whether gastroduodenal tem (SYNAPSE VINCENT; Fuji Film Medical, Tokyo, Japan). An motilities influence the motion of upper abdominal organs such as oblique plane through the long-axis dimension of the gastric antrum the liver, pancreas and kidneys. To address this objective, we used was obtained to measure gastric motility. Gastric motility was quan- cine-MRI to assess differences in the motion of upper abdominal tified based on the amplitude and velocity of the peristaltic wave organs in healthy volunteers during fasting and postprandial states. with the smallest antrum diameter. Amplitude was calculated as the difference between the maximum and minimum antrum diameters at MATERIALS AND METHODS the point of the smallest diameter in the wave. Velocity was calculated Volunteers and conditions of the stomach as the extension or contraction velocity of the antrum at the same An appropriate institutional review board approved this study. Written point. The amplitude and velocity were defined as follows (Fig. 1): informed consent was obtained from each volunteer. A total of 35 (17 men and 18 women) volunteers were included in this study. Amplitude() mm = Maximum diameter(d_ )– max Volunteers were excluded if they had an ongoing abdominal disease, a Minimum diameter (_ d ) min history of abdominal surgery and/or general contraindications for MRI. The median age of participants was 37 years old (range, 27–61) Extension or contraction velocity() mm/s=(d_ – d_ ) /Δt max min and the median body mass index was 22.2 kg/m (range, 17.8–35.4). Volunteers fasted for a 5-h period with no food, then a 3-h peri- Δ( t sec) = extension or contraction time between d_ and d_ min max od with no food or liquid, before their first MRI examination. Volunteers ingested jelly that was previously used to obtain clear A sagittal plane through the long-axis dimension of the duodenal images of the gastric wall and fold (360 mL, 360 kcal, Weider in jel- second portion was obtained to measure duodenal motility. ly; Morinaga & Co, Tokyo, Japan; [8]) immediately following the Duodenal motility was evaluated at the point with the smallest first cine-MRI, then underwent the second cine-MRI in the post- diameter and was quantified by measuring the difference between prandial state, 30 min after jelly ingestion. maximum and minimum diameters during the scanning time. Abdominal organ motions were measured at the left and right Cine-MRI lobes of the liver; pancreatic head, body and tail; and both kidneys. MRI examinations were performed in the supine position using a Three orthogonal planes were selected for the measurement of the 1.5T MR scanner (Signa, HDxT, 1.5T, GE, Healthcare, Milwaukee, respective organ regions: left lobe of the liver—the proximal bifur- WI). A body array coil was not used in order to avoid abdominal cation of the lateral branch of the left portal vein, the right lobe of compression. Cine-MRI was performed using a steady-state free pre- the liver—the first main bifurcation of the right portal vein; the pan- cession sequence (fast imaging employing steady-state acquisition creatic head, body and tail—the center of each structure; both kid- sequence: repetition time = 4.71 ms, echo time = 2.08 ms, flip neys—the center of each structure. Abdominal organ motions were Fig. 1. Oblique images of the gastric antrum with steady-state free precession sequence in a volunteer with minimum (A) and maximum (B) antral diameters of a peristaltic wave. Maximum diameter = d_max, minimum diameter = d_min, Δt = extension time between d_min and d_max. Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 Assessment of abdominal organ motion using cine-MRI in different gastric motilities � 839 Fig. 2. Examples of measurement points for abdominal organ motion. (A) Left lobe of the liver in the sagittal image. (B) Pancreatic body and tail in the coronal image. (C) Left kidney in the axial image. Arrows indicate the measurement points of organ edges. White arrow, left–right direction; black arrow, antero–posterior direction; white arrowhead. caudal–cranial direction. quantified by calculating the maximal displacement of the organ edges in the left–right (LR), antero–posterior (AP), and caudal–cra- nial (CC) directions on all three planes (Figs 2 and 3). Clearly identifiable positions of abdominal organs were selected for the measurements, and we measured the same points of each organ in the fasting and postprandial states. All measurements were per- formed with the consensus by two radiologists. Statistical analysis The Wilcoxon signed-rank test was used for statistical analysis. A test value of P < 0.05 was considered statistically significant. All stat- istical analyses were performed using JMP version 13.0.0 (SAS Institute Inc., Cary, NC, USA). RESULTS Fig. 3. An example of the measurement for maximum The median amplitudes of the antral peristaltic wave in the fasting displacement (Δd) of the caudal–cranial direction of the left and postprandial states were 7.7 mm (range, 1.5–27.7) and 15.1 kidney in the sagittal image. (A) The most caudal position mm (range, 2.9–35.1), respectively (P < 0.01). The median veloci- of the left kidney. (B) The most cranial position of the left ties of the wave in the fasting and postprandial states were 1.3 mm/s kidney. (range, 0.2–3.5) and 2.5 mm/s (range, 0.7–4.2), respectively (P < 0.01). The median differences between the maximal and min- imal duodenum diameters were 7.5 mm (range, 2.6–12.9) for the fasting state and 9.4 mm (range, 2.9–20.5) for the postprandial state powerful and regular peristaltic contractions in the distal stomach (P = 0.07). Median abdominal organ displacements in the two mix and grind the food, while it moves to the duodenum [14]. states are shown in Table 1. Box plots of abdominal organ displace- In the present study, the amplitude and velocity of the antrum ments are shown in Figs 4–6. The median displacements of all peristaltic wave in the postprandial state increased significantly com- organs in three directions in the fasting and postprandial states ran- pared with those in the fasting state; moreover, increased gastric ged from 0.9 to 2.9 mm (median, 1.8), and from 1.0 to 2.9 mm motility was confirmed at the gastric antrum in the postprandial (median, 2.0), respectively. Significant increases in organ motion in state. Teramoto et al. [10] studied duodenal motility after the inges- the postprandial state were observed within the following organs. tion of a liquid meal in healthy volunteers using cine-MRI; they Right lobe of the liver—LR direction on the coronal plane: 1.4–1.7 found that the shift in the center of gravity of the duodenum and mm; pancreatic head—AP on axial: 1.9–2.6 mm; left kidney—AP the velocity of duodenal wall motion were both smallest immedi- on sagittal: 1.0–1.2 mm, LR on axial: 0.9–1.2 mm, CC on sagittal: ately after ingestion, and then increased significantly in the subse- 2.0–2.5 mm, CC on coronal: 1.8–2.1 mm; right kidney—AP on axial: quent 30 and 60 min, respectively. However, significant differences 0.9–1.0 mm, LR on axial: 1.0–1.2 mm, LR on coronal: 1.1–1.4 mm. in duodenal motility were not observed between fasting and post- prandial states in our study. We analyzed duodenal motility as only DISCUSSION the difference between the maximum and minimum duodenal dia- During and after food intake, the proximal stomach relaxes and meters. The difference in the evaluation methods for duodenal motility between the two studies might be the cause of the conflict- serves initially as a reservoir for a large amount of food, and then pushes the food distally through tonic contractions. Simultaneously, ing results. Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 � H. Nonaka et al. Table 1. Median displacements of abdominal organs Organs Median displacements, mm (range) Anterior–posterior Left–right Caudal–cranial Axial Sagittal Axial Coronal Sagittal Coronal Left lobe of the liver Fasting 1.4 (0.7–4.9) 1.1 (0.4–6.3) 1.9 (0.5–6.0) 1.7 (0.6–4.9) 2.9 (0.7–16.2) 2.6 (1.0–11.3) Postprandial 1.5 (0.6–3.9) 1.5 (0.5–7.6) 1.8 (0.7–7.3) 1.9 (0.9–6.8) 2.6 (1.1–11.0) 2.5 (0.9–7.8) P-value 0.57 0.52 0.47 0.22 0.59 0.69 Right lobe of the liver Fasting 1.6 (0.8–6.0) 1.6 (0.5–8.8) 1.4 (0.7–3.6) 1.4 (0.6–3.4) 2.5 (1.1–17.0) 2.3 (0.6–14.2) Postprandial 1.6 (0.6–4.7) 1.4 (0.7–6.6) 1.5 (0.8–3.2) 1.7 (0.7–5.5) 2.8 (0.8–19.7) 2.9 (1.5–28.3) P-value 0.38 0.69 0.81 0.04 0.55 0.39 Pancreatic head Fasting 1.9 (1.4–4.8) 2.1 (0.7–8.0) 1.8 (0.9–4.2) 2.1 (0.7–5.4) 2.2 (0.8–11.3) 2.8 (1.5–9.4) Postprandial 2.6 (1.1–7.2) 2.4 (1.4–6.5) 2.1 (1.2–19.9) 2.3 (1.1–5.7) 2.6 (1.0–5.0) 2.6 (1.0–8.9) P-value <0.01 0.09 0.23 0.11 0.12 0.71 Pancreatic body and tail Fasting 2.1 (0.7–5.8) 2.0 (0.7–4.7) 1.9 (0.7–12.2) 1.6 (0.6–3.8) 2.1 (1.0–12.6) 1.9 (0.8–14.2) Postprandial 2.0 (1.0–9.4) 2.1 (1.1–5.5) 2.2 (0.9–9.0) 2.0 (0.8–5.4) 2.8 (1.2–8.5) 2.6 (0.9–9.7) P-value 0.82 0.32 0.5 0.05 0.15 0.32 Left kidney Fasting 1.0 (0.4–6.1) 1.0 (0.6–4.1) 0.9 (0.5–5.0) 1.1 (0.4–6.4) 2.0 (1.0–8.4) 1.8 (0.8–13.9) Postprandial 1.1 (0.4–3.8) 1.2 (0.6–6.5) 1.2 (0.6–7.0) 1.2 (0.4–6.5) 2.5 (0.9–12.3) 2.1 (0.8–20.0) P-value 0.17 0.01 <0.01 0.11 0.02 0.03 Right kidney Fasting 0.9 (0.5–2.1) 1.1 (0.5–5.9) 1.0 (0.3–6.3) 1.1 (0.5–2.0) 1.9 (0.5–12.9) 1.8 (0.5–14.4) Postprandial 1.0 (0.4–4.0) 1.2 (0.7–4.8) 1.2 (0.4–7.6) 1.4 (0.7–2.9) 2.4 (0.7–17.7) 1.8 (0.7–15.5) P-value 0.04 0.12 0.04 0.03 0.14 0.33 Significant increases in abdominal organ displacements in the to the discrepancy between two planes. Although significant postprandial state were observed in the following organs: the right increases were observed in several abdominal organ displacements, lobe of the liver in the LR direction, the pancreas head in the AP the differences in median abdominal displacements between the direction, the left kidney in the three directions, and the right kid- fasting and postprandial states were <1 mm. ney in the AP and LR directions. The displacements of the left kid- Wysocka et al. [15] analyzed gastric motion in the fasting and ney (in the CC direction) and the right kidney (in the LR postprandial state with 10 healthy volunteers, using cine-MRI with a direction) exhibited significant increases on two planes; other dis- 30-second breathing hold. The median of mean gastric displace- placements exhibited increases in motion on only one plane. Due to ments from the baseline position was small, rarely exceeding 1.1 the irregular organ shape and trajectory, one plane alone could not mm, and the median standard deviation of the displacements was completely detect abdominal organ motion, which might have led also small (range, 2.1–3.6 mm) in the fasting and postprandial Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 Assessment of abdominal organ motion using cine-MRI in different gastric motilities � Fig. 4. Box plot of displacements of the liver. The bottom and top of each box indicate the first and third quartiles; the bar inside the box indicates the median. Upper and lower whiskers show the maximum and minimum values within 1.5 interquartile measurements from the box, respectively. The black points indicate outliers. The asterisk indicates P < 0.05. AP = antero-posterior, LR = left-right, CC = caudal-cranial, Axi = axial plane, Sag = sagittal plane, Cor = coronal plane. Fig. 5. Box plot of displacements of the pancreas. The bottom and top of each box indicate the first and third quartiles; the bar inside the box indicates the median. Upper and lower whiskers show the maximum and minimum values within 1.5 interquartile measurements from the box, respectively. The black points indicate outliers. The asterisk indicates P < 0.05. AP = antero-posterior, LR = left-right, CC = caudal-cranial, Axi = axial plane, Sag = sagittal plane, Cor = coronal plane. states. Both the displacements and the standard deviations did not possibility of a minimal difference in abdominal organ motion differ significantly between the two states. The authors concluded induced by gastric motion between the fasting and postprandial that non-respiratory intra-fractional gastric motion was small, and states. that gastric position was stable after small and standard meals. Kirilova et al. [12] used cine-MRI to measure the motion of liver Although we measured gastric motility at the antrum using cine- tumors during free breathing, and found that the average CC tumor MRI, similarly to previous studies [6–8], Wysocka et al. [15] mea- motion was 15.5 mm, AP motion was 10.1 mm and LR motion was sured it with the gastric outline on the axial, coronal, and oblique 7.5 mm. Moerland et al. [16] studied respiration-induced motion of planes. Taking their findings into account, it seems reasonable that the kidneys using MRI. Displacements in a tilted coronal plane in our study, abdominal organ displacements increased by a small through the longitudinal axis of the kidneys under normal respir- margin in the postprandial state; this may be attributed to the ation conditions were 2–24 mm in the left kidney and 4–35 mm in Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 � H. Nonaka et al. Fig. 6. Box plot of displacements of the kidneys. The bottom and top of each box indicate the first and third quartiles; the bar inside the box indicates the median. Upper and lower whiskers show the maximum and minimum values within 1.5 interquartile measurements from the box, respectively. The black points indicate outliers. The asterisks indicate P < 0.05. AP = antero-posterior, LR = left-right, CC = caudal-cranial, Axi = axial plane, Sag = sagittal plane, Cor = coronal plane. the right kidney; furthermore, displacements under forced respir- organs or tumors in previous studies [12, 13, 16]. Therefore, while ation conditions were much larger in the left and right kidneys at we could not eliminate respiratory motions of these organs com- 10–66 mm and 10–86 mm, respectively. Heerkens et al. [13] used pletely, these motions were minimized compared with previous cine-MRI to evaluate the pancreatic tumor motion during breathing; breathing studies. Second, other internal organ motions (i.e., cardiac the average CC tumor motion was 15 mm, AP motion was 5 mm beats and small and large intestine activities) were also not elimi- and LR motion was 3 mm. Compared with these organ or tumor nated in our study. However, it is difficult to evaluate the abdominal motions that were mainly induced by respiration, the differences in organ motion induced by gastroduodenal peristaltic motion separ- abdominal organ displacement between the fasting and postprandial ately from the organ motion induced by other internal activities. states in our study were quite small. Third, we did not observe a significant increase in duodenal Consequently, it can be seen that the abdominal organ displace- motility. We had planned to quantify duodenal motility based on ments under different conditions of fasting and postprandial states both the velocity and amplitude of the duodenal peristaltic wave, are quite small. Although we should add a margin for the intra- but we could not obtain images clear enough to smoothly visualize fractional abdominal organ motion itself, it is not necessary to take peristaltic motion as a series of waves. Therefore, we only quantified changes in the intra-fractional abdominal organ motions in the two the difference between the maximum and minimum diameter of the different states into consideration in most treatment planning or duodenum. Although our measurement method was not enough to irradiation for these organs. That is, strict management such as fast- assess the change in duodenal motility, taking Teramoto’s reports ing before irradiation or large expansion of the internal margin in [10] and the P value of our analysis in duodenal motility into con- planning, does not appear to be necessary for the management of sideration, it is probable that duodenum motility actually increased the intra-fractional abdominal organ motion changes under different in the 35 healthy volunteers after injection. gastric motilities in the two states. Fourth, further analyses with real tumor displacement may be Our study had some limitations. First, cine-MRI was performed required to reveal the uncertainty in intra-fractional abdominal with breath holding to eliminate abdominal organ motion induced tumor motion that is induced by gastrointestinal motility. by respiration; however, respiratory motion of these organs was not completely eliminated. We found that 35 of all measured abdominal CONCLUSIONS organ displacements exceeded 10 mm, of which 33 were in the CC Although the motion of several abdominal organs increased in the direction. Notably, we observed that every organ with displacements postprandial state, the differences in abdominal organ displacement >10 mm in the CC direction moved synchronously with the dia- between the fasting and postprandial states were minimal. phragm. Although several organ displacements were quite large, Therefore, our study suggests that it is not necessary to strictly man- most of them were in the CC direction, which was likely respiratory age gastric conditions, or to add excessive margins in most treat- motion caused by the failure of subjects to hold their breath. ment planning and irradiation for the intra-fractional abdominal However, abdominal organ motion in our study with breath holding organ motion changes under different gastric motilities in the fasting was substantially smaller than respiratory motion of abdominal and postprandial states. Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 Assessment of abdominal organ motion using cine-MRI in different gastric motilities � 843 8. Baba S, Sasaki A, Nakajima J et al. Assessment of gastric motor ACKNOWLEDGEMENTS function by cine magnetic resonance imaging. J Gastroenterol We thank Dr. Jin Yamamoto for his support. We presented this Hepatol 2009;24:1401–6. study with a slightly different analysis in a smaller number of volun- 9. Baumann T, Kuesters S, Grueneberger J et al. Time-resolved teers at the 59th Annual Meeting of American Society for Radiation MRI after ingestion of liquids reveals motility changes after lap- Oncology in 2017. aroscopic sleeve gastrectomy—preliminary results. Obes Surg 2011;21:95–101. CONFLICT OF INTEREST 10. Teramoto H, Shimizu T, Yogo H et al. Assessment of gastric The authors state that there are no conflicts of interest. emptying and duodenal motility upon ingestion of a liquid meal using rapid magnetic resonance imaging. Exp Physiol 2012;97: REFERENCES 516–24. 1. Suramo I, Päivänsalo M, Myllylä V. Cranio-caudal movements 11. Teramoto H, Shimizu T, Yogo H et al. Gastric emptying and of the liver, pancreas and kidneys in respiration. Acta Radiol duodenal motility upon intake of a liquid meal with monoso- Diagn (Stockh) 1984;25:129–31. dium glutamate in healthy subjects. Physiol Rep 2014;2:1–12. 2. Davies SC, Hill AL, Holmes RB et al. Ultrasound quantitation 12. Kirilova A, Lockwood G, Choi P et al. Three-dimensional of respiratory organ motion in the upper abdomen. Br J Radiol motion of liver tumors using cine-magnetic resonance imaging. 1994;67:1096–102. Int J Radiat Oncol Biol Phys 2008;71:1189–95. 3. Brandner ED, Wu A, Chen H et al. Abdominal organ motion 13. Heerkens HD, van Vulpen M, van den Berg CA et al. MRI- measured using 4D CT. Int J Radiat Oncol Biol Phys 2006;65: based tumor motion characterization and gating schemes for 554–60. radiation therapy of pancreatic cancer. Radiother Oncol 2014; 4. Balter JM, Ten Haken RK, Lawrence TS et al. Uncertainties in 111:252–7. CT-based radiation therapy treatment planning associated with 14. Janssen P, Vanden Berghe P, Verschueren S et al. Review art- patient breathing. Int J Radiat Oncol Biol Phys 1996;36:167–74. icle: the role of gastric motility in the control of food intake. 5. Aruga T, Itami J, Aruga M et al. Target volume definition for Aliment Pharmacol Ther 2011;33:880–94. upper abdominal irradiation using CT scans obtained during inhale 15. Wysocka B, Moseley J, Brock K et al. Assessment of nonrespira- and exhale phases. IntJRadiat OncolBiolPhys 2000;48:465–9. tory stomach motion in healthy volunteers in fasting and post- 6. Ajaj W, Goehde SC, Papanikolaou N et al. Real time high reso- prandial states. Pract Radiat Oncol 2014;4:288–93. lution magnetic resonance imaging for the assessment of gastric 16. Moerland MA, van den Bergh AC, Bhagwandien R et al. The motility disorders. Gut 2004;53:1256–61. influence of respiration induced motion of the kidneys on the 7. Ajaj W, Lauenstein T, Papanikolaou N et al. Real-time high-reso- accuracy of radiotherapy treatment planning, a magnetic reson- lution MRI for the assessment of gastric motility: pre- and post- ance imaging study. Radiother Oncol 1994;30:150–4. pharmacological stimuli. J Magn Reson Imaging 2004;19:453–8. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Radiation Research Oxford University Press

Assessment of abdominal organ motion using cine magnetic resonance imaging in different gastric motilities: a comparison between fasting and postprandial states

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© The Author(s) 2019. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.
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Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 Journal of Radiation Research, Vol. 60, No. 6, 2019, pp. 837–843 doi: 10.1093/jrr/rrz054 Advance Access Publication: 24 August 2019 Assessment of abdominal organ motion using cine magnetic resonance imaging in different gastric motilities: a comparison between fasting and postprandial states 1,2, 1 3 Hotaka Nonaka , Hiroshi Onishi , Makoto Watanabe and 1,4 Vu Hong Nam Department of Radiology, University of Yamanashi, Institutional address: 1110 Shimokato, Chuo City, Yamanashi, 409-3898, Japan Department of Radiology, Fujiyoshida Municipal Hospital, Institutional address: 6530 Kamiyoshida, Fujiyoshida City Yamanashi, 403-0005, Japan Department of Radiological Technology, Fujiyoshida Municipal Hospital, Institutional address: 6530 Kamiyoshida, Fujiyoshida City Yamanashi, 403-0005, Japan Department of Oncology and Nuclear Medicine, Hospital 175, Institutional address: 786 Nguyen Kiem Street, Ward 3, Go Vap District, Ho Chi Minh City, 9856013, Viet Nam *Corresponding author. Department of Radiology, University of Yamanashi, Institutional address: 1110 Shimokato, Chuo City, Yamanashi 409-3898, Japan. Tel: +81 55 2731111; Fax: +81 55 2739766; Email: nonakahotaka@gmail.com (Received 28 December 2018; revised 24 March 2019; editorial decision 26 June 2019) ABSTRACT This study assessed abdominal organ motion induced by gastroduodenal motilities in volunteers during fasting and postprandial states, using cine magnetic resonance imaging (cine-MRI). Thirty-five volunteers underwent cine-MRI while holding their breath in the fasting and postprandial states. Gastric motility was quantified by the amplitude and velocity of antral peristaltic waves. Duodenal motility was evaluated as the change of duodenal diameter. Abdominal organ motion was measured in the liver, pancreas and kidneys. Motion was quantified by calculating maximal organ displacement in the left–right, antero–posterior and caudal–cranial directions. Median antral amplitude and velocity in the fasting and postprandial states were 7.7 and 15.1 mm (P < 0.01), and 1.3 and 2.5 mm/s (P < 0.01), respectively. Duodenal motility did not change. Median displacement for all organs ranged from 0.9 to 2.9 mm in the fasting state and from 1.0 to 2.9 mm in the postprandial state. Significant increases in abdominal organ displacement in the postprandial state were observed in the right lobe of the liver, pancreatic head and both kidneys. Differences in the median displacement of these organs between the two states were all <1 mm. Although the motion of several abdominal organs increased in the postprandial state, the difference between the two states was quite small. Thus, our study suggests that treatment planning and irradi- ation need not include strict management of gastric conditions, nor the addition of excess margins to compen- sate for differences in the intra-fractional abdominal organ motion under different gastric motilities in the fasting and postprandial states. Keywords: abdominal organ motion; gastric motility; cine magnetic resonance imaging; intra-fractional motion INTRODUCTION overall abdominal organ motion. Abdominal organ motion induced Recently, high-precision radiotherapy, such as stereotactic body radi- by respiration has been previously studied [1–3], and unreliable ation therapy or intensity modulated radiation therapy, has become tumor dose and normal tissue volume due to respiration on treat- available to treat abdominal tumors. High-precision radiotherapy ment planning computed tomography has been reported [4, 5]. requires an accurate understanding of the intra-fractional motions of Following recent technological advances, cine magnetic resonance abdominal tumors and organs. Respiration contributes greatly to imaging (cine-MRI) has been proposed to monitor gastric or © The Author(s) 2019. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. � 837 Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 � H. Nonaka et al. gastroduodenal motilities [6–11]; cine-MRI has been previously angle = 40°, slice thickness = 5 mm, matrix = 288 × 192, field of used for measurements of abdominal tumor motion that are primar- view = 360 mm). A series of 24 images of the stomach, duodenum, ily induced by respiration [12, 13]. However, there is a lack of liver, pancreas and kidneys was collected over a 20-s period. focused studies of the abdominal motion induced by gastrointestinal Breathing was held, following voice guidance, to eliminate abdom- motilities, the diet management needed to control such motion, and inal organ motion induced by respiration. the internal margins required to take this motion into account when planning irradiation treatment of these organs. To the best of our Assessment of gastroduodenal motilities and abdominal knowledge, this is the first study of the relationship between intra- organ displacements fractional abdominal organ motions, and gastroduodenal motilities. Each series of images was measured using a 3D image analysis sys- The aim of this study was to determine whether gastroduodenal tem (SYNAPSE VINCENT; Fuji Film Medical, Tokyo, Japan). An motilities influence the motion of upper abdominal organs such as oblique plane through the long-axis dimension of the gastric antrum the liver, pancreas and kidneys. To address this objective, we used was obtained to measure gastric motility. Gastric motility was quan- cine-MRI to assess differences in the motion of upper abdominal tified based on the amplitude and velocity of the peristaltic wave organs in healthy volunteers during fasting and postprandial states. with the smallest antrum diameter. Amplitude was calculated as the difference between the maximum and minimum antrum diameters at MATERIALS AND METHODS the point of the smallest diameter in the wave. Velocity was calculated Volunteers and conditions of the stomach as the extension or contraction velocity of the antrum at the same An appropriate institutional review board approved this study. Written point. The amplitude and velocity were defined as follows (Fig. 1): informed consent was obtained from each volunteer. A total of 35 (17 men and 18 women) volunteers were included in this study. Amplitude() mm = Maximum diameter(d_ )– max Volunteers were excluded if they had an ongoing abdominal disease, a Minimum diameter (_ d ) min history of abdominal surgery and/or general contraindications for MRI. The median age of participants was 37 years old (range, 27–61) Extension or contraction velocity() mm/s=(d_ – d_ ) /Δt max min and the median body mass index was 22.2 kg/m (range, 17.8–35.4). Volunteers fasted for a 5-h period with no food, then a 3-h peri- Δ( t sec) = extension or contraction time between d_ and d_ min max od with no food or liquid, before their first MRI examination. Volunteers ingested jelly that was previously used to obtain clear A sagittal plane through the long-axis dimension of the duodenal images of the gastric wall and fold (360 mL, 360 kcal, Weider in jel- second portion was obtained to measure duodenal motility. ly; Morinaga & Co, Tokyo, Japan; [8]) immediately following the Duodenal motility was evaluated at the point with the smallest first cine-MRI, then underwent the second cine-MRI in the post- diameter and was quantified by measuring the difference between prandial state, 30 min after jelly ingestion. maximum and minimum diameters during the scanning time. Abdominal organ motions were measured at the left and right Cine-MRI lobes of the liver; pancreatic head, body and tail; and both kidneys. MRI examinations were performed in the supine position using a Three orthogonal planes were selected for the measurement of the 1.5T MR scanner (Signa, HDxT, 1.5T, GE, Healthcare, Milwaukee, respective organ regions: left lobe of the liver—the proximal bifur- WI). A body array coil was not used in order to avoid abdominal cation of the lateral branch of the left portal vein, the right lobe of compression. Cine-MRI was performed using a steady-state free pre- the liver—the first main bifurcation of the right portal vein; the pan- cession sequence (fast imaging employing steady-state acquisition creatic head, body and tail—the center of each structure; both kid- sequence: repetition time = 4.71 ms, echo time = 2.08 ms, flip neys—the center of each structure. Abdominal organ motions were Fig. 1. Oblique images of the gastric antrum with steady-state free precession sequence in a volunteer with minimum (A) and maximum (B) antral diameters of a peristaltic wave. Maximum diameter = d_max, minimum diameter = d_min, Δt = extension time between d_min and d_max. Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 Assessment of abdominal organ motion using cine-MRI in different gastric motilities � 839 Fig. 2. Examples of measurement points for abdominal organ motion. (A) Left lobe of the liver in the sagittal image. (B) Pancreatic body and tail in the coronal image. (C) Left kidney in the axial image. Arrows indicate the measurement points of organ edges. White arrow, left–right direction; black arrow, antero–posterior direction; white arrowhead. caudal–cranial direction. quantified by calculating the maximal displacement of the organ edges in the left–right (LR), antero–posterior (AP), and caudal–cra- nial (CC) directions on all three planes (Figs 2 and 3). Clearly identifiable positions of abdominal organs were selected for the measurements, and we measured the same points of each organ in the fasting and postprandial states. All measurements were per- formed with the consensus by two radiologists. Statistical analysis The Wilcoxon signed-rank test was used for statistical analysis. A test value of P < 0.05 was considered statistically significant. All stat- istical analyses were performed using JMP version 13.0.0 (SAS Institute Inc., Cary, NC, USA). RESULTS Fig. 3. An example of the measurement for maximum The median amplitudes of the antral peristaltic wave in the fasting displacement (Δd) of the caudal–cranial direction of the left and postprandial states were 7.7 mm (range, 1.5–27.7) and 15.1 kidney in the sagittal image. (A) The most caudal position mm (range, 2.9–35.1), respectively (P < 0.01). The median veloci- of the left kidney. (B) The most cranial position of the left ties of the wave in the fasting and postprandial states were 1.3 mm/s kidney. (range, 0.2–3.5) and 2.5 mm/s (range, 0.7–4.2), respectively (P < 0.01). The median differences between the maximal and min- imal duodenum diameters were 7.5 mm (range, 2.6–12.9) for the fasting state and 9.4 mm (range, 2.9–20.5) for the postprandial state powerful and regular peristaltic contractions in the distal stomach (P = 0.07). Median abdominal organ displacements in the two mix and grind the food, while it moves to the duodenum [14]. states are shown in Table 1. Box plots of abdominal organ displace- In the present study, the amplitude and velocity of the antrum ments are shown in Figs 4–6. The median displacements of all peristaltic wave in the postprandial state increased significantly com- organs in three directions in the fasting and postprandial states ran- pared with those in the fasting state; moreover, increased gastric ged from 0.9 to 2.9 mm (median, 1.8), and from 1.0 to 2.9 mm motility was confirmed at the gastric antrum in the postprandial (median, 2.0), respectively. Significant increases in organ motion in state. Teramoto et al. [10] studied duodenal motility after the inges- the postprandial state were observed within the following organs. tion of a liquid meal in healthy volunteers using cine-MRI; they Right lobe of the liver—LR direction on the coronal plane: 1.4–1.7 found that the shift in the center of gravity of the duodenum and mm; pancreatic head—AP on axial: 1.9–2.6 mm; left kidney—AP the velocity of duodenal wall motion were both smallest immedi- on sagittal: 1.0–1.2 mm, LR on axial: 0.9–1.2 mm, CC on sagittal: ately after ingestion, and then increased significantly in the subse- 2.0–2.5 mm, CC on coronal: 1.8–2.1 mm; right kidney—AP on axial: quent 30 and 60 min, respectively. However, significant differences 0.9–1.0 mm, LR on axial: 1.0–1.2 mm, LR on coronal: 1.1–1.4 mm. in duodenal motility were not observed between fasting and post- prandial states in our study. We analyzed duodenal motility as only DISCUSSION the difference between the maximum and minimum duodenal dia- During and after food intake, the proximal stomach relaxes and meters. The difference in the evaluation methods for duodenal motility between the two studies might be the cause of the conflict- serves initially as a reservoir for a large amount of food, and then pushes the food distally through tonic contractions. Simultaneously, ing results. Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 � H. Nonaka et al. Table 1. Median displacements of abdominal organs Organs Median displacements, mm (range) Anterior–posterior Left–right Caudal–cranial Axial Sagittal Axial Coronal Sagittal Coronal Left lobe of the liver Fasting 1.4 (0.7–4.9) 1.1 (0.4–6.3) 1.9 (0.5–6.0) 1.7 (0.6–4.9) 2.9 (0.7–16.2) 2.6 (1.0–11.3) Postprandial 1.5 (0.6–3.9) 1.5 (0.5–7.6) 1.8 (0.7–7.3) 1.9 (0.9–6.8) 2.6 (1.1–11.0) 2.5 (0.9–7.8) P-value 0.57 0.52 0.47 0.22 0.59 0.69 Right lobe of the liver Fasting 1.6 (0.8–6.0) 1.6 (0.5–8.8) 1.4 (0.7–3.6) 1.4 (0.6–3.4) 2.5 (1.1–17.0) 2.3 (0.6–14.2) Postprandial 1.6 (0.6–4.7) 1.4 (0.7–6.6) 1.5 (0.8–3.2) 1.7 (0.7–5.5) 2.8 (0.8–19.7) 2.9 (1.5–28.3) P-value 0.38 0.69 0.81 0.04 0.55 0.39 Pancreatic head Fasting 1.9 (1.4–4.8) 2.1 (0.7–8.0) 1.8 (0.9–4.2) 2.1 (0.7–5.4) 2.2 (0.8–11.3) 2.8 (1.5–9.4) Postprandial 2.6 (1.1–7.2) 2.4 (1.4–6.5) 2.1 (1.2–19.9) 2.3 (1.1–5.7) 2.6 (1.0–5.0) 2.6 (1.0–8.9) P-value <0.01 0.09 0.23 0.11 0.12 0.71 Pancreatic body and tail Fasting 2.1 (0.7–5.8) 2.0 (0.7–4.7) 1.9 (0.7–12.2) 1.6 (0.6–3.8) 2.1 (1.0–12.6) 1.9 (0.8–14.2) Postprandial 2.0 (1.0–9.4) 2.1 (1.1–5.5) 2.2 (0.9–9.0) 2.0 (0.8–5.4) 2.8 (1.2–8.5) 2.6 (0.9–9.7) P-value 0.82 0.32 0.5 0.05 0.15 0.32 Left kidney Fasting 1.0 (0.4–6.1) 1.0 (0.6–4.1) 0.9 (0.5–5.0) 1.1 (0.4–6.4) 2.0 (1.0–8.4) 1.8 (0.8–13.9) Postprandial 1.1 (0.4–3.8) 1.2 (0.6–6.5) 1.2 (0.6–7.0) 1.2 (0.4–6.5) 2.5 (0.9–12.3) 2.1 (0.8–20.0) P-value 0.17 0.01 <0.01 0.11 0.02 0.03 Right kidney Fasting 0.9 (0.5–2.1) 1.1 (0.5–5.9) 1.0 (0.3–6.3) 1.1 (0.5–2.0) 1.9 (0.5–12.9) 1.8 (0.5–14.4) Postprandial 1.0 (0.4–4.0) 1.2 (0.7–4.8) 1.2 (0.4–7.6) 1.4 (0.7–2.9) 2.4 (0.7–17.7) 1.8 (0.7–15.5) P-value 0.04 0.12 0.04 0.03 0.14 0.33 Significant increases in abdominal organ displacements in the to the discrepancy between two planes. Although significant postprandial state were observed in the following organs: the right increases were observed in several abdominal organ displacements, lobe of the liver in the LR direction, the pancreas head in the AP the differences in median abdominal displacements between the direction, the left kidney in the three directions, and the right kid- fasting and postprandial states were <1 mm. ney in the AP and LR directions. The displacements of the left kid- Wysocka et al. [15] analyzed gastric motion in the fasting and ney (in the CC direction) and the right kidney (in the LR postprandial state with 10 healthy volunteers, using cine-MRI with a direction) exhibited significant increases on two planes; other dis- 30-second breathing hold. The median of mean gastric displace- placements exhibited increases in motion on only one plane. Due to ments from the baseline position was small, rarely exceeding 1.1 the irregular organ shape and trajectory, one plane alone could not mm, and the median standard deviation of the displacements was completely detect abdominal organ motion, which might have led also small (range, 2.1–3.6 mm) in the fasting and postprandial Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 Assessment of abdominal organ motion using cine-MRI in different gastric motilities � Fig. 4. Box plot of displacements of the liver. The bottom and top of each box indicate the first and third quartiles; the bar inside the box indicates the median. Upper and lower whiskers show the maximum and minimum values within 1.5 interquartile measurements from the box, respectively. The black points indicate outliers. The asterisk indicates P < 0.05. AP = antero-posterior, LR = left-right, CC = caudal-cranial, Axi = axial plane, Sag = sagittal plane, Cor = coronal plane. Fig. 5. Box plot of displacements of the pancreas. The bottom and top of each box indicate the first and third quartiles; the bar inside the box indicates the median. Upper and lower whiskers show the maximum and minimum values within 1.5 interquartile measurements from the box, respectively. The black points indicate outliers. The asterisk indicates P < 0.05. AP = antero-posterior, LR = left-right, CC = caudal-cranial, Axi = axial plane, Sag = sagittal plane, Cor = coronal plane. states. Both the displacements and the standard deviations did not possibility of a minimal difference in abdominal organ motion differ significantly between the two states. The authors concluded induced by gastric motion between the fasting and postprandial that non-respiratory intra-fractional gastric motion was small, and states. that gastric position was stable after small and standard meals. Kirilova et al. [12] used cine-MRI to measure the motion of liver Although we measured gastric motility at the antrum using cine- tumors during free breathing, and found that the average CC tumor MRI, similarly to previous studies [6–8], Wysocka et al. [15] mea- motion was 15.5 mm, AP motion was 10.1 mm and LR motion was sured it with the gastric outline on the axial, coronal, and oblique 7.5 mm. Moerland et al. [16] studied respiration-induced motion of planes. Taking their findings into account, it seems reasonable that the kidneys using MRI. Displacements in a tilted coronal plane in our study, abdominal organ displacements increased by a small through the longitudinal axis of the kidneys under normal respir- margin in the postprandial state; this may be attributed to the ation conditions were 2–24 mm in the left kidney and 4–35 mm in Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 � H. Nonaka et al. Fig. 6. Box plot of displacements of the kidneys. The bottom and top of each box indicate the first and third quartiles; the bar inside the box indicates the median. Upper and lower whiskers show the maximum and minimum values within 1.5 interquartile measurements from the box, respectively. The black points indicate outliers. The asterisks indicate P < 0.05. AP = antero-posterior, LR = left-right, CC = caudal-cranial, Axi = axial plane, Sag = sagittal plane, Cor = coronal plane. the right kidney; furthermore, displacements under forced respir- organs or tumors in previous studies [12, 13, 16]. Therefore, while ation conditions were much larger in the left and right kidneys at we could not eliminate respiratory motions of these organs com- 10–66 mm and 10–86 mm, respectively. Heerkens et al. [13] used pletely, these motions were minimized compared with previous cine-MRI to evaluate the pancreatic tumor motion during breathing; breathing studies. Second, other internal organ motions (i.e., cardiac the average CC tumor motion was 15 mm, AP motion was 5 mm beats and small and large intestine activities) were also not elimi- and LR motion was 3 mm. Compared with these organ or tumor nated in our study. However, it is difficult to evaluate the abdominal motions that were mainly induced by respiration, the differences in organ motion induced by gastroduodenal peristaltic motion separ- abdominal organ displacement between the fasting and postprandial ately from the organ motion induced by other internal activities. states in our study were quite small. Third, we did not observe a significant increase in duodenal Consequently, it can be seen that the abdominal organ displace- motility. We had planned to quantify duodenal motility based on ments under different conditions of fasting and postprandial states both the velocity and amplitude of the duodenal peristaltic wave, are quite small. Although we should add a margin for the intra- but we could not obtain images clear enough to smoothly visualize fractional abdominal organ motion itself, it is not necessary to take peristaltic motion as a series of waves. Therefore, we only quantified changes in the intra-fractional abdominal organ motions in the two the difference between the maximum and minimum diameter of the different states into consideration in most treatment planning or duodenum. Although our measurement method was not enough to irradiation for these organs. That is, strict management such as fast- assess the change in duodenal motility, taking Teramoto’s reports ing before irradiation or large expansion of the internal margin in [10] and the P value of our analysis in duodenal motility into con- planning, does not appear to be necessary for the management of sideration, it is probable that duodenum motility actually increased the intra-fractional abdominal organ motion changes under different in the 35 healthy volunteers after injection. gastric motilities in the two states. Fourth, further analyses with real tumor displacement may be Our study had some limitations. First, cine-MRI was performed required to reveal the uncertainty in intra-fractional abdominal with breath holding to eliminate abdominal organ motion induced tumor motion that is induced by gastrointestinal motility. by respiration; however, respiratory motion of these organs was not completely eliminated. We found that 35 of all measured abdominal CONCLUSIONS organ displacements exceeded 10 mm, of which 33 were in the CC Although the motion of several abdominal organs increased in the direction. Notably, we observed that every organ with displacements postprandial state, the differences in abdominal organ displacement >10 mm in the CC direction moved synchronously with the dia- between the fasting and postprandial states were minimal. phragm. Although several organ displacements were quite large, Therefore, our study suggests that it is not necessary to strictly man- most of them were in the CC direction, which was likely respiratory age gastric conditions, or to add excessive margins in most treat- motion caused by the failure of subjects to hold their breath. ment planning and irradiation for the intra-fractional abdominal However, abdominal organ motion in our study with breath holding organ motion changes under different gastric motilities in the fasting was substantially smaller than respiratory motion of abdominal and postprandial states. Downloaded from https://academic.oup.com/jrr/article-abstract/60/6/837/5554320 by DeepDyve user on 06 December 2019 Assessment of abdominal organ motion using cine-MRI in different gastric motilities � 843 8. Baba S, Sasaki A, Nakajima J et al. Assessment of gastric motor ACKNOWLEDGEMENTS function by cine magnetic resonance imaging. J Gastroenterol We thank Dr. Jin Yamamoto for his support. We presented this Hepatol 2009;24:1401–6. study with a slightly different analysis in a smaller number of volun- 9. Baumann T, Kuesters S, Grueneberger J et al. Time-resolved teers at the 59th Annual Meeting of American Society for Radiation MRI after ingestion of liquids reveals motility changes after lap- Oncology in 2017. aroscopic sleeve gastrectomy—preliminary results. Obes Surg 2011;21:95–101. CONFLICT OF INTEREST 10. Teramoto H, Shimizu T, Yogo H et al. Assessment of gastric The authors state that there are no conflicts of interest. emptying and duodenal motility upon ingestion of a liquid meal using rapid magnetic resonance imaging. Exp Physiol 2012;97: REFERENCES 516–24. 1. Suramo I, Päivänsalo M, Myllylä V. Cranio-caudal movements 11. Teramoto H, Shimizu T, Yogo H et al. Gastric emptying and of the liver, pancreas and kidneys in respiration. Acta Radiol duodenal motility upon intake of a liquid meal with monoso- Diagn (Stockh) 1984;25:129–31. dium glutamate in healthy subjects. Physiol Rep 2014;2:1–12. 2. Davies SC, Hill AL, Holmes RB et al. Ultrasound quantitation 12. Kirilova A, Lockwood G, Choi P et al. Three-dimensional of respiratory organ motion in the upper abdomen. Br J Radiol motion of liver tumors using cine-magnetic resonance imaging. 1994;67:1096–102. Int J Radiat Oncol Biol Phys 2008;71:1189–95. 3. Brandner ED, Wu A, Chen H et al. Abdominal organ motion 13. Heerkens HD, van Vulpen M, van den Berg CA et al. MRI- measured using 4D CT. Int J Radiat Oncol Biol Phys 2006;65: based tumor motion characterization and gating schemes for 554–60. radiation therapy of pancreatic cancer. Radiother Oncol 2014; 4. Balter JM, Ten Haken RK, Lawrence TS et al. Uncertainties in 111:252–7. CT-based radiation therapy treatment planning associated with 14. Janssen P, Vanden Berghe P, Verschueren S et al. Review art- patient breathing. Int J Radiat Oncol Biol Phys 1996;36:167–74. icle: the role of gastric motility in the control of food intake. 5. Aruga T, Itami J, Aruga M et al. Target volume definition for Aliment Pharmacol Ther 2011;33:880–94. upper abdominal irradiation using CT scans obtained during inhale 15. Wysocka B, Moseley J, Brock K et al. Assessment of nonrespira- and exhale phases. IntJRadiat OncolBiolPhys 2000;48:465–9. tory stomach motion in healthy volunteers in fasting and post- 6. Ajaj W, Goehde SC, Papanikolaou N et al. Real time high reso- prandial states. Pract Radiat Oncol 2014;4:288–93. lution magnetic resonance imaging for the assessment of gastric 16. Moerland MA, van den Bergh AC, Bhagwandien R et al. The motility disorders. Gut 2004;53:1256–61. influence of respiration induced motion of the kidneys on the 7. Ajaj W, Lauenstein T, Papanikolaou N et al. Real-time high-reso- accuracy of radiotherapy treatment planning, a magnetic reson- lution MRI for the assessment of gastric motility: pre- and post- ance imaging study. Radiother Oncol 1994;30:150–4. pharmacological stimuli. J Magn Reson Imaging 2004;19:453–8.

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Published: Nov 22, 2019

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