Fluoroscopic and CT enteroclysis in children: initial experience, technical feasibility, and utility
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- Brown, S., Applegate, K.E., Sandrasegaran, K. et al. Pediatr Radiol (2008) 38: 497. doi:10.1007/s00247-008-0754-8
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Partial small-bowel obstruction can be difficult to diagnose on clinical examination. These obstructions might not be detected on routine abdominal/pelvic CT.
To evaluate the feasibility, safety, and techniques of fluoroscopic enteroclysis (FE) and CT enteroclysis (CTE), and to review their indications and findings in children.
Materials and methods
We retrospectively reviewed all enteroclysis studies in children younger than 18 years performed between January 2002 and March 2007. We correlated the results with other abdominal imaging and surgical and pathological findings.
The review revealed 112 FE and 74 CTE studies performed in 175 children (mean age 14 years, range 3–18 years). FE and CTE studies were performed most commonly for evaluation of known Crohn disease (FE 38%, CTE 29%) and abdominal pain (FE 26%, CTE 26%). One FE study was terminated because of patient anxiety, and one CTE study was terminated because of patient discomfort. No complications of FE or CTE were reported. The findings were normal in 54% of the FE studies and 46% of the CTE studies. The most common small bowel diagnoses were Crohn disease (FE 34%, CTE 28%) and partial small bowel obstruction (FE 3%, CTE 10%). Two FE studies (2%) and 14 CTE studies (19%) showed abnormalities outside the small bowel. In 54 patients with inflammatory bowel disease, 11 FE studies and 25 CTE studies showed additional bowel abnormalities. Overall, 14 and 21 patients had surgery as a result of the findings of FE and CTE, respectively.
FE and CTE are safe, feasible, and accurate in depicting small-bowel pathology in children. These techniques can be particularly useful in children with Crohn disease involving the small bowel.
KeywordsFluoroscopic enteroclysisCT enteroclysisChildrenCrohn diseaseSmall bowel obstruction
Radiological evaluation of the small bowel can be challenging because of its inaccessibility to endoscopy and its length and redundancy on imaging. Small-bowel follow-through (SBFT) has been the most commonly performed method of investigation because of its ease of use, availability, and low cost, but recently several other methods of small-bowel investigation have been developed.
Abdominal multidetector CT (MDCT) is fast and accessible, and provides images of consistently high quality. Not surprisingly, it is increasingly used to evaluate both intestinal and extraintestinal pathology. Both children and adults, however, show wide variability in their ingestion of oral contrast agent, resulting in under-distention and poor visualization of the small bowel. Small-bowel polyps, strictures, and adhesions are under-detected, especially in patients with Crohn disease . Newer techniques include CT enterography [2–5], MR enterography , and capsule endoscopy [7–12]. CT enterography uses a high-osmolar, neutral-density oral contrast agent to both distend the bowel and allow more detailed visualization of the mucosal enhancement patterns. Yet like conventional MDCT of the abdomen, it requires a meticulous oral preparation protocol and ingestion of oral contrast agent. Children are especially unlikely to tolerate ingestion in a short period of the high volume of oral contrast agent needed. Capsule endoscopy provides direct visualization of the intestinal mucosa via multiple radio-transmitted images (average of 55,000 ) as it passes through the bowel. Although this method provides excellent visualization of the mucosa, its use might not be safe in young children .
First popularized in the 1970s, fluoroscopic enteroclysis (FE) was designed to provide a volume challenge to distend and better visualize the small bowel when compared to the barium SBFT . Compared to SBFT and abdominal CT, this technique has been shown in adults to improve the detection and definition of small-bowel pathology, including intraluminal masses, mucosal diseases, stenosis/stricture, fistula, and partial obstruction [1, 16]. CT enteroclysis (CTE) combines the advantages of MDCT and enteroclysis. MR enteroclysis (MRE) might be a valuable tool to diagnose small-bowel disease, as well, especially in children because of its lack of radiation [17–23]. MRE, however, has several logistical hurdles, including nasoduodenal intubation within the MRI room, motion artefacts (cardiovascular, respiratory, and bowel peristalsis), and breath-holding for sequences that last 20–30 s.
FE and CTE are diagnostic tools for the detection of small-bowel pathology, particularly strictures in children with Crohn disease. Several studies in the literature have focused on their utility and safety in adult populations, but no studies to our knowledge have described their use in children. We discuss here our fluoroscopic and CT techniques and sedation protocol in children. We also review the clinical history and indications for enteroclysis, document its safety and feasibility, and evaluate its added value by comparing the results of enteroclysis with those of other imaging modalities and with patient outcomes using clinical, surgical, and pathological follow-up.
Materials and methods
This study was approved by our institutional review board with a waiver of informed consent. The retrospective study included three large teaching hospitals. From the radiology information system, we identified all FE and CTE studies performed on children, 18 years of age and younger, between January 2002 and March 2007. The electronic records of children who had received enteroclysis were reviewed, and pertinent findings from the clinical and surgical history prior to and following the enteroclysis were recorded, including the reported indications for enteroclysis, the findings of enteroclysis, history of known inflammatory bowel disease (IBD), and whether action had been taken based on the findings of the enteroclysis. Although we understand that using the reported indication might not reflect the most comprehensive reason as to why the study was performed, we thought it still added important comparative information. We reviewed the radiology nursing and clinical records of these patients for any complications from sedation or anesthesia.
The enteroclysis procedure was described to the child and family prior to parental informed consent. All patients had nothing to eat or drink (NPO) after midnight the evening prior to the procedure. In order to minimize anxiety, children were allowed to bring their favorite stuffed toy animal with them and play music in the background. The radiology nurse provided the primary contact and information to the family for the procedure. All children were monitored by the nurse and with pulse oximetry and automatic blood pressure monitoring.
A peripheral intravenous cannula was placed and 1 mg midazolam (Versed, Baxter Healthcare, Deerfield, IL; maximum dose 0.1 mg/kg), 25 µg fentanyl citrate (Fentanyl, Hospira, Lake Forest, IL; maximum dose 3 µg/kg), and metoclopramide were administered intravenously at the beginning of the procedure. Lidocaine 2% jelly was then placed in the nasal passage via syringe to ensure lubrication for the nasoenteric tube. Sedation was titrated to the child’s anxiety and discomfort throughout the procedure.
Rarely, the child did not meet the criteria for sedation by the radiology nursing staff and underwent either general anesthesia or did not undergo sedation.
Fluoroscopic enteroclysis technique
After initial sedation, a nasoduodenal catheter (MEC; Cook, Bloomington, IN) was inserted. For most children, a 13F tube was advanced through the pylorus to the fourth portion of the duodenum under fluoroscopic guidance. For small children younger than 8 years, a smaller balloon angiography catheter from the interventional radiology suite was used. The catheter balloon was initially inflated to 15–20 ml to ensure filling of the bowel lumen and prevent backflow of contrast agent into the stomach. Prior to infusion of contrast agent into the small bowel, intravenous glucagon was given. The enteroclysis contrast agent mixture used for FE varied by hospital and over time but included barium, methyl cellulose (until it was removed from the market), and iodinated contrast agents. The majority of patients, however, received contrast agent made of one-third 18% diatrizoate meglumine (Cystografin; Bracco, Princeton, NJ) and two-thirds 0.1% barium sulfate (VoLumen; E-Z-EM, Lake Success, NY). VoLumen has a radiographic density of about 20 HU. It contains sorbitol to maintain luminal distention and guar gum to increase viscosity .
The nasoenteric tube was connected to a hydraulic pump (RS-7800 Minipump; Renal Systems, Minneapolis, MN), and the enteral agent infused initially at a rate of 60 ml/min in order to assess contrast flow and bowel motility. If contrast agent refluxed into the stomach, the balloon was inflated further and the tube was repositioned. The contrast agent infusion rate was increased incrementally to a maximum of 120 ml/min (less in young children) under fluoroscopic observation . If the child reported abdominal pain or the contrast agent advance slowed during infusion, the contrast agent infusion rate was decreased. The total infusion volume in older children was approximately 1,500 ml but varied widely depending on the child’s size, bowel distention, and history of bowel resection. During FE without CTE, the child was examined with multiple compression and noncompression spot fluoroscopic images during the infusion of contrast agent until contrast was seen in the cecum. The medical records and imaging reports were reviewed for complications including bowel perforation and bleeding.
CT enteroclysis technique
When the contrast agent reached the cecum, the infusion was stopped and the child was transported to the CT facility. The parameters for MDCT of the abdomen and pelvis were identical to the routine low-dose, weight-based parameters for conventional CT imaging. Images were acquired on a 4-, 16-, 40-, or 64-slice CT scanner (GE Medical Systems, Waukesha, WI, or Philips Medical Systems, Cleveland, OH). Imaging parameters included 120 kVp, 2.5- to 5-mm slice thickness with the current protocol using volumetric acquisition and reconstruction in all three planes. When the FE or CTE was complete, the balloon was deflated, and the stomach was aspirated. The child was then transferred to the radiology recovery area to be cared for by the radiology nursing or anesthesia staff.
Image analysis and comparison
Fluoroscopic and CT images were interpreted on PACS. CTE images were read using a window of 1,180 and level of 160 by a pediatric or gastrointestinal radiologist, depending on the study hospital location.
For this study, we reviewed all available imaging and diagnostic procedures within a 2-month period both preceding and following enteroclysis, including SBFT and abdominal CT images, and surgical and pathology results, in order to determine the final diagnosis and patient outcome. We reviewed pathology reports from surgery and endoscopic biopsies, and the reports were used for findings and diagnosis. We determined whether the imaging comparisons agreed, disagreed, or were noncomparable. Noncomparable findings were those that were not in the organ systems examined by both modalities. For example, an abdominal CT scan would evaluate all of the bowel as well as the solid organs, whereas the comparison FE imaging would be limited to the small bowel and did not evaluate the stomach, colon, or solid organs.
All data were tabulated in an Excel spreadsheet for reporting. We compared the indications for FE and CTE and their findings using chi-squared analysis. P values ≤0.05 were considered significant.
Demographic data for the children undergoing enteroclysis
FE studies (n = 113)
CTE studies (n = 74)
Sex, n (%)
Prior abdominal surgery, n (%)
Known Crohn disease, n (%)
Known ulcerative colitis, n (%)
The mean age of those undergoing FE was 14 years (median 15 years, range 8–18 years), and 57 (50%) were boys. Of those undergoing FE, 16 (14%) had prior abdominal surgery, 35 (31%) had known Crohn disease, and 1 (1%) had known ulcerative colitis. The mean age of those undergoing CTE was 14.5 years (median 15 years, range 3–18 years), and 32 (43%) were boys. Of those undergoing CTE, 15 (21%) had prior abdominal surgery, 20 (28%) had known Crohn disease, and five (7%) had known ulcerative colitis.
Feasibility and safety
Of the 113 FE studies, 112 were performed without difficulty and of the 73 CTE studies, 72 were performed without difficulty. One FE study was terminated because of patient anxiety, and one CTE study was terminated due to patient discomfort during the infusion of contrast agent into the small bowel. There were no complications.
Of 112 FE studies, 111 (99%) were performed under conscious sedation as per the pediatric enteroclysis protocol at the hospital and of 74 CTE studies, 67 (91%) were performed under conscious sedation. Four CTE studies were performed under general anesthesia because of a previous paradoxical response to Versed, young age (3 and 5 years), and severe autism with oppositional defiant disorder. One CTE study was performed without sedation or anesthesia because there was a mature tract to the stomach into which a Frederick-Miller tube was inserted. Using radiology nursing and medical chart reviews, we were unable to determine why one CTE study and one FE study were performed under general anesthesia and why one CTE study was performed without conscious sedation. There were no complications from either sedation or anesthesia.
Clinical indications for FE (n = 112) and CTE (n = 74) studies
FE, n (%)
CTE, n (%)
Crohn disease (known)
Suspected small-bowel obstruction
Suspected Crohn disease
Irritable bowel syndrome
Nausea/vomiting – no surgical history
Familial polyposis syndrome
Juvenile polyposis syndrome
Protein losing enteropathy
Ulcerative colitis (known)
Iliac adenopathy and jejunal thickening
Fluoroscopic and CT enteroclysis findings
Primary diagnoses by FE (n = 112) and CTE (n = 72)
FE, n (%)
CTE, n (%)
Partial small-bowel obstruction
Adhesions without obstruction
Adenocarcinoma and polyps in colon
With regard to diagnoses unrelated to the small bowel, FE studies showed one child with possible colonic obstruction and one child with appendicitis. CTE studies showed three children (4%) with hiatal hernia and two children (3%) with ovarian cysts, as well as one child each with renal cysts, polysplenia, splenic infarcts, diffuse osteosclerosis, left renal duplication, colonic pneumatosis, bilateral pars defects, and pancolitis.
Crohn disease findings on FE (n = 38) and CTE (n = 20) studies
Crohn disease diagnoses
FE, n (%)
CTE, n (%)
Stricture / partial SBO
Number with multiple findings
Ulcerative colitis was diagnosed in four children by CTE. Two of the four children had partial small-bowel obstructions, one had small bowel to anterior abdominal wall adhesions without evidence of obstruction, and one had a thickened colonic wall. None of the four children had multiple abnormalities. Ulcerative colitis was not diagnosed by FE.
Abdominal CT correlation
Imaging correlations within 2 months of enteroclysis
No. of studies compared
Correlation, n (%)
Of 74 children, 21 (28%) had conventional CT scans within 2 months of CTE. CTE findings were concordant with CT findings in 16 (76%), discordant in 3 (14%), and noncomparable in 2 (10%). The noncomparable studies showed interval resolution of lymphadenopathy over 18 days and mild ascites over 2 days between the CT scan and CTE performed subsequently. No treatment was administered to either patient during these time periods. In the three children with discordant studies, CT showed no abnormality and the subsequent CTE showed abnormalities (one child each with jejunal wall thickening, Crohn disease of the mid-ileum, and partial small-bowel obstruction; Table 5). These three discordant results show that CTE provided additional information to CT.
SBFT was performed in four children within 2 months of FE. The findings were concordant in two children (50%), discordant in one (25%), and noncomparable in one (25%). In the child with noncomparable findings, SBFT showed gastric reflux and FE showed no abnormality. In the child with discordant findings, SBFT showed Crohn disease of the distal ileum with cobblestoning and stricture and FE showed evidence of stricture 2 months later. The diagnosis of Crohn disease had been previously confirmed by biopsy. It is possible that the distal ileal disease resolved in the interval with therapy (Table 5).
SBFT was performed in 11 children within 2 months of CTE. The findings were concordant in nine children (82%) and discordant in two. In the child with discordant findings, SBFT showed nonobstructive narrowing of the ileum and CTE showed no abnormality. The narrowing was later thought to represent focally collapsed bowel or spasm, as it was not present on any previous or later studies. In the other child with discordant findings, SBFT showed a cecal fistula and CTE showed ulcerative colitis with colonic wall-thickening but no fistula. The child underwent a total colectomy 27 days after CTE and 43 days after SBFT for ulcerative colitis. Pathology did not show evidence of a cecal fistula (Table 5).
Of 112 surgical or pathological procedures (from endoscopic biopsies), 67 (59%) were performed within 2 months of FE. Endoscopy or colonoscopy was performed in 17 children. The surgical/pathological results were concordant in 39 children (58%), discordant in 1, and noncomparable in 28 (42%) as the surgical/pathological specimens were not small-bowel samples. In the child with discordant results, FE showed no abnormality, but a terminal ileal stricture was found and resected at surgery. Although not considered discordant, we note that in one child FE showed a polyp that was found to be an ileal duplication cyst at surgery (Table 5).
Of 74 surgical/pathological procedures, 24 (46%) were performed within 2 months of CTE. The surgical/pathological results were concordant in 27 children (79%), discordant in 1, and noncomparable in 6 (18%) as the surgical/pathological specimens were not small-bowel samples. In the child with discordant results, CTE showed no abnormality but subsequent ileal biopsy performed during colonoscopy on the same day was consistent with Crohn disease (Table 5).
Overall, 14 of 112 children who underwent FE and 21 of 74 children who underwent CTE also underwent previously unscheduled surgery within 2 months of the FE or CTE because of the findings of these examinations. In particular, segmental small-bowel resections were performed in nine, exploratory adhesolysis in four, and colectomy in four.
Enteroclysis was found to be safe and feasible in a large and diverse pediatric population. New diagnoses were made in 20 of 112 FE studies (19%) and 18 of 74 CTE studies (24%). Enteroclysis was mainly utilized to evaluate patients with known or suspected Crohn disease and partial small-bowel obstruction. The CTE results sometimes provided a definitive answer about whether the small bowel, when volume-challenged, had a partial obstruction from internal hernia, adhesions or stricture. Compared to SBFT and conventional CT, FE and CTE added diagnostic information. This was particularly helpful in children with active IBD of the small bowel, such as strictures, sinus tracts, fistulas, and phlegmon. CTE provided additional information about both small-bowel and extraintestinal pathology to FE and altered the surgical management of 28% of patients, as compared with 12% of patients who underwent FE.
Although this study focused on the pathological findings of enteroclysis in children, the importance of a normal study in excluding a partial small-bowel obstruction or new onset of Crohn disease is easily overlooked. Gastroenterologists use the enteroclysis study to rule out pathology, particularly partial small-bowel obstruction, in patients with chronic abdominal pain. One child with Crohn disease had abdominal pain out of proportion to her clinical examination and laboratory findings. We reassured the pediatric gastroenterologist that a stricture or partial bowel obstruction was not causing her symptoms. For some other children, the pediatric gastroenterologist, surgeon, and radiologist must work together to build evidence about the need for therapeutic intervention. For 3 years Barloon et al.  followed 83 patients who had a normal enteroclysis to assess its negative predictive value. Only six were found to have small-bowel pathology, meaning that the enteroclysis had 92% specificity for ruling in any disease .
Crohn disease is a common cause of small-bowel pathology in both adults and children , yet there are no optimal disease activity markers. As such, its evaluation with imaging is critical. Capsule endoscopy is equivalent or superior to other modalities in the evaluation of known ileal Crohn disease [7–12]. It is the method of choice in patients with unexplained gastrointestinal bleeding or a hereditary polyposis syndrome [11, 28]. However, capsule endoscopy cannot be used when there is concern for stricture or partial bowel obstruction, or to evaluate extraintestinal complications. While capsule endoscopy is increasingly used in adults, it cannot be used in young children because of the smaller size of the bowel [12, 14].
Alternative imaging methods for evaluation of the small bowel are less invasive than enteroclysis. CT enterography is a less invasive method than enteroclysis that depicts inflammation of the small bowel associated with Crohn disease and its findings correlate more closely with the ileoscopic and histological severity in Crohn disease than those of SBFT [2–5]. MR enterography avoids the radiation exposure of CT, but has more issues with motion artefacts [6, 29]. Similarly, MR enteroclysis is being developed to avoid ionizing radiation, but it shows more bowel, vascular, and respiratory motion artefacts . In our experience, the main limitation of enterography in children is the lack of adequate distention of the small bowel, especially the distal ileum, often the area of interest in patients with Crohn disease. We have found that children are usually unwilling to drink large amounts of oral contrast agent over the short time interval recommended for optimal imaging.
In order to identify low-grade obstructions, small-bowel volume challenge is crucial to show small-caliber changes . In adults, CTE is the imaging modality of choice for the localization and characterization of small-bowel neoplasms [8, 32, 33]. Enteroclysis in adults might also be the most accurate imaging method for the diagnosis of complications from Crohn disease and small-bowel obstructions [1, 21]. Its disadvantage is that a nasoenteric tube is invasive and its use requires sedation. An added disadvantage, especially because of the increased risk in children, is radiation exposure, principally from the CT component. Radiation doses related to enteroclysis and CTE are as significant an issue as they are in the use of abdominal and pelvic CT studies in these patients. It is important to minimize fluoroscopy time and perform FE and CTE using the principle of ALARA . We use a low-dose technique that is weight-based, identical to that used in our conventional abdominal MDCT. Because many patients with Crohn disease undergo repeated CT imaging for evaluation of symptoms and signs, performing CTE at the same dose is no less justified and provides more clinical information in selected patients. Although the technique for FE varies, one study has demonstrated that the radiation dose is lower for CTE than for FE in adults . In either case, performing serial examinations that expose children to ionizing radiation should be quantified so that cumulative radiation exposure can be determined and adequate patient safety maintained. Currently, we do not have a system in place to monitor and tabulate total radiation exposure to individual patients for any of our ionizing radiation examinations.
The main advantage of CTE over other imaging modalities is depiction of luminal, mural, and extramural abnormalities. With improved MDCT technology and the advent of CTE in 1994, thinner collimation and volumetric image acquisition allows review in all three planes [17, 36–39]. CTE has been found to be superior to FE in the diagnosis and characterization of mucosal abnormalities, intramural and extramural Crohn disease, and low-grade small-bowel obstruction [17, 19]. Because of these findings and our own experience with both FE and CTE, we have performed CTE exclusively in all children since November 2005.
In complex clinical situations, the pediatric gastroenterologist, pediatric surgeon, and pediatric radiologist must make decisions about the appropriate treatment for children with abdominal pain. CTE is an important tool in the evaluation of the small bowel in children. The radiologist, the radiology technologist, and the sedation nurse work as a team to complete the procedure safely, allay patient and family anxiety, and discuss the enteroclysis results at the end of the study.
Both FE and CTE were well tolerated and safe and provided additional information to that provided by SBFT and abdominal CT in a number of children. The pediatric gastroenterologist and pediatric surgeon use the results of FE and CTE for treatment planning. Compared to FE, CTE showed more abnormalities both in the small bowel and outside the bowel. For this reason, we perform CTE rather than FE. We believe that CTE has an important role in evaluating the small bowel in children, particularly in those with Crohn disease.