Intramural Fat in eliac Disease Gastrointestinal Imaging linical Observations Francis J. Scholz 1 Spencer. Behr hristopher D. Scheirey Scholz FJ, Behr S, Scheirey D Keywords: abdominal imaging, celiac disease, duodenitis, duodenum, gastrointestinal imaging, intramural fat, jejunitis, jejunum, sprue DOI:10.2214/AJR.07.2109 Received February 22, 2007; accepted after revision May 20, 2007. 1 All authors: Department of Diagnostic Radiology, Lahey linic, 41 Mall Rd., Burlington, MA 01805. Address correspondence to F. J. Scholz (francis.j.scholz@lahey.org). AJR 2007; 189:786 790 0361 803X/07/1894 786 American Roentgen Ray Society Intramural Fat in the Duodenum and Proximal Small Intestine in Patients with eliac Disease OBJETIVE. The purpose of this article is to describe and illustrate intramural fat in the duodenum and jejunum, to our knowledge a previously undescribed finding in celiac disease. ONLUSION. eliac disease is known to produce inflammation of the duodenum and jejunum. We propose that postinflammatory intramural fat deposition occurs in a distribution likely unique for celiac disease. T scans of the chest and abdomen obtained for many indications include these portions of the bowel. eliac disease is now recognized as a common disease, and the recognition of intramural fat in the duodenum and jejunum on T may allow earlier diagnosis. eliac disease is a common disease that is often difficult to diagnose. T scans are currently obtained for a variety of indications. We wished to determine if there were any unique findings on T to allow the earlier diagnosis of celiac disease. Materials and Methods Methods Retrospective review of charts, images, and laboratory results of patients with proven celiac disease was approved by the hospital institutional review board. Subjects were obtained from a list of patients proven by our laboratory to have tissue transglutaminase antibody titers diagnostic of celiac disease. Following this list, we used the PAS to review all abdominal and pelvic T scans. One hundred thirty-six T scans of the chest or abdomen obtained in 82 patients with celiac disease proven by tissue transglutaminase or biopsy were reviewed by a gastrointestinal radiologist with 33 years of experience. After the initial review revealed striking intramural fat in the duodenum and jejunum in some patients, all scans were systematically reviewed for this finding. Negative attenuation (in Hounsfield units) was required in the wall of the bowel to be considered intramural fat. Results Prominent intramural fat in the duodenum and jejunum was noted in 11 patients. A 12th patient was discovered during the study, and subsequent chart review established the diagnosis of celiac disease. In axial cross section of bowel, fat created a circle of low density (Fig. 1A). In longitudinal cross section it created longitudinal stripes of fat (Fig. 2). In some patients the fat was noted within the folds of the bowel (Fig. 1). To our knowledge, intramural fat in the duodenum and jejunum has not been previously described. We present four illustrative examples of this pattern. Examples Patient 1, an 81-year-old woman, was screened for colorectal cancer with virtual colonoscopy which showed a thick layer of intramural duodenal fat. T showed the penetration of the common bile duct through the wall to the mucosa (Fig. 1). Review of the patient s chart showed a much earlier proven diagnosis of celiac disease, which had not been noted in her chart for decades. One year before her T, an upper gastrointestinal series was performed for pain, and a scarred duodenum with diverticula but no ulceration was noted. Her medical history included psoriatic arthritis treated with methotrexate. Patient 2, a 65-year-old woman with known celiac disease, presented to her primary care physician with iron deficiency anemia. An upper gastrointestinal barium study showed a fold-free duodenum with a bubbly bulb (Fig. 2). The appearance of the jejunum was featureless, with weblike strictures indicating active celiac disease that was subsequently successfully treated with strict gluten restriction. Four years later a cough and an abnormal chest radiograph prompted T of her thorax, which showed a 786 AJR:189, October 2007
Intramural Fat in eliac Disease Fig. 1 81-year-old woman (patient 1) who underwent virtual colonoscopy screening for colorectal cancer. Review of her chart showed much earlier proven diagnosis of celiac disease that had not been noted in chart for decades. Medical history also included psoriatic arthritis treated with methotrexate. A and B, T scans show thick layer of intramural duodenal fat. Penetration of common bile duct (arrow) through wall to mucosa is seen (A). oronal reconstruction also defines penetration of duct (arrow) across layer of intramural fat (B)., Axial slice distal to A shows fat in duodenal folds creating linear array (arrows) of perpendicularly oriented deposits of fat. D, Upper gastrointestinal series performed for pain 1 year before A and B shows a scarred duodenum with diverticula (arrows) but no ulceration. Fig. 2 65-year-old woman (patient 2) with known celiac disease and iron deficiency anemia. Her medical history includes seasonal allergies, gastroesophageal reflux disease, and hyperlipidemia. A and B, Upper gastrointestinal barium studies show fold-free duodenum with bubbly bulb (arrow, A) and featureless appearance of jejunum (B), where weblike strictures indicate active celiac disease., T scans of thorax 4 years after A and B show layer of intramural fat in duodenum (straight arrow) and jejunum (curved arrows). A A B B D AJR:189, October 2007 787
layer of submucosal fat in the duodenum and jejunum. Her medical history included seasonal allergies, gastroesophageal reflux disease, and hyperlipidemia. Patient 3, a 78-year-old woman with known adult-onset celiac disease, presented to her primary care physician with right-sided abdominal pain. An upper gastrointestinal barium study was performed in June 1999, at which time celiac disease with a bubbly nodularity in the bulb and in the fold-free duodenal sweep (Fig. 3) was noted in addition to a malabsorption pattern. In March 2002, she presented to a pulmonologist because of progressive shortness of breath; a T scan showed a fine line of intramural fat density in the jejunum and duodenum. Her medical history included asthma that was occasionally treated with prednisone, recurrent sinusitis, and gastroesophageal reflux disease. Patient 4, a 37-year-old man with no significant medical history, presented to his primary care physician with right lower quadrant A B Fig. 3 78-year-old woman (patient 3) with known adult-onset celiac disease and right-sided abdominal pain. Her medical history includes asthma occasionally treated with prednisone, recurrent sinusitis, and gastroesophageal reflux disease. A and B, Upper gastrointestinal barium studies show celiac disease with bubbly nodularity in bulb and in fold-free duodenal sweep (arrows). Malabsorption pattern was also seen., Three years later, after patient reported progressive shortness of breath, T scans show fine line of intramural fat density (arrows) in jejunum in addition to intramural duodenal fat. pain. Abdominopelvic T was ordered to evaluate for appendicitis, but none was seen. The patient s pain persisted, prompting upper endoscopy and colonoscopy 11 months later. eliac disease was diagnosed at biopsies of the small intestine. The patient s subsequent antiendomysial antibody test was strongly positive, confirming celiac disease. Review of the original T scan showed intramural fat in the duodenum and jejunum (Fig. 4). Discussion eliac disease is the result of gluten ingestion stimulating an autoimmune destruction of small-bowel mucosal epithelium in patients with a genetic predisposition. It is now recognized as a common disease, with a prevalence of about 1% in the Western hemisphere [1]. In certain subgroups, its prevalence is markedly higher. Three to six percent of patients with type 1 diabetes and 10 15% of symptomatic patients with iron deficiency anemia have celiac disease [1]. Disease activity varies from patient to patient, but it is thought to be a lifelong process that may become symptomatic at any time. Destruction of the protective villous lining of the duodenum and jejunum in celiac disease predisposes to inflammation from gastric, biliary, and pancreatic secretions. Once denuded, the duodenal bulb and descending duodenum, exposed to gastric acid, are most susceptible. Abnormalities noted in the duodenum on endoscopy [2] and upper gastrointestinal series [3 5] are believed to be sensitive nonlaboratory abnormalities indicating celiac disease. The tissue transglutaminase antibody test is the most sensitive and widely used test to detect the disease in symptomatic patients. As discussed by Tomei et al. [6] in a review of 28 patients, certain findings are suggestive of celiac disease on T. These include loss of jejunal folds with an increased number of ileal folds, increased fluid in the small bowel, intestinal dilatation, vascular engorgement, transient asymptomatic intussusception, duodenal inflammation 788 AJR:189, October 2007
Intramural Fat in eliac Disease Fig. 4 37-year-old man (patient 4) with no significant medical history and right lower quadrant pain. Abdominopelvic T scans show intramural fat in duodenum (straight arrows) and jejunum (curved arrows). Smallbowel biopsies led to diagnosis of celiac disease. and thickening, and lymphadenopathy. Four of 28 patients were noted to have isolated thickening of the duodenum. One patient was noted to have low density in the wall of the duodenum that was not further characterized. The most specific finding noted to suggest celiac disease was reversal of the jejunoileal fold pattern. Intramural fat deposition, thought to be a response to prior bowel inflammation, has been described in the terminal and distal ileum in patients with rohn s disease [7]. It has also been noted in the colon in patients with both rohn s disease and ulcerative colitis [8 10]. Intramural fat has been also been described in the terminal ileum and colon in asymptomatic patients with no known prior disease process [11]. Although it is considered a chronic response to inflammation, intramural fat has been shown to occur as rapidly as 12 days after a patient has undergone chemotherapy for lymphoma or leukemia [12]. A single report of intramural fat has been described in a patient with radiation enteritis [13]. To our knowledge, neither fat deposition in the duodenum and jejunum nor its cause due to celiac disease has previously been reported. With a prevalence of 1% or more, celiac disease is common and statistically can be expected to be seen in about 1% or more of all T scans. eliac disease may be difficult to diagnose. Although antibody tests are highly sensitive and specific, early symptoms are nonspecific and vague. Nondiarrheal presentations, including irritable bowel, anemia, guaiac-positive stools, osteoporosis, renal stone disease, and malignancy, now exceed presentations with diarrhea [14]. The severity of celiac disease may wax and wane over time, further delaying its diagnosis. Our fourth example is a patient who had an 11- month interval after the T examination before antibody testing finally confirmed the diagnosis. During this interval, the patient had additional fruitless doctor visits and tests. Other inflammatory diseases of the proximal small bowel might produce intramural fat. rohn s disease does occur in the duodenum and jejunum and might produce intramural fat, as has been described in the distal small bowel and colon. None of our patients had evidence of rohn s disease, but all had proven celiac disease. Systematic examination of the T scans of patients with duodenal rohn s disease may reveal intramural fat. In our experience, we have never noted duodenal fat in the T scans of patients with proximal small-bowel rohn s disease, nonsteroidal antiinflammatory drug-induced enteritis, or chronic pancreatitis. Because of the large number of T scans that visualize the upper abdomen, including routine T of the abdomen and pelvis, T of the chest, virtual colonoscopy, and T for renal stone disease, we believe intramural fat should be a useful and perhaps specific diagnostic finding in celiac disease. In our retrospective review, 11 (13.4%) of 82 patients had intramural fat. The 12th case was prospectively diagnosed during the course of our study. The lack of sensitivity of this finding is probably due to the extreme variability in the severity of disease expression, which is related to both genetic predisposition and gluten dietary load. However, this finding may be the first (patient 4) or the last (patient 1) indication of celiac disease. Although other clinical, laboratory, and radiographic findings may become normal with either a decrease in or complete cessation of gluten ingestion, intramural fat may be a long-lasting residual of the disease or may persist in patients with subclinical disease activity. Patient 1 had no abdominal symptoms when the striking intramural fat was discovered during virtual colonoscopy. The disease was no longer considered a disease by the patient, but rather a dietary condition. Her physician had actually stopped listing celiac disease in chart notes. eliac disease is a significant and greatly underdiagnosed disease process according to the 2004 National Institutes of Health (NIH) consensus panel [15]. Although we have not established the sensitivity of proximal small-bowel fat deposition, when intramural fat is found in the duodenum and proximal small bowel on T, celiac disease must be considered. Further observation and study are required to determine whether intramural fat in the duodenal and jejunum may occur in other disease processes. We believe from our study and review of the literature that it may be the most specific and unique T finding of celiac disease. References 1. Dube, Rostom A, Sy R, et al. The prevalence of celiac disease in average-risk and at-risk Western European populations: a systematic review. Gastroenterology 2005; 128[4 suppl 1]:S57 S67 2. Brocchi E, orazza GR, aletti G, Treggiari EA, Barbara L, Gasbarrini G. Endoscopic demonstration of loss of duodenal folds in the diagnosis of celiac disease. N Engl J Med 1988; 319:741 744 3. Nicolette, Tully TE. The duodenum in celiac sprue. AJR 1971; 113:248 254 4. Jones B, Bayless TM, Hamilton SR, Yardley JH. Bubbly duodenal bulb in celiac disease: radiologic pathologic correlation. AJR 1984; 142:119 122 5. Marn S, Gore RM, Ghahremani GG. Duodenal manifestations of nontropical sprue. Gastrointest Radiol 1986; 11:30 35 6. Tomei E, Diacinti D, Marini M, et al. Abdominal T findings may suggest coeliac disease. Dig Liver Dis 2005; 37:402 406 AJR:189, October 2007 789
FOR YOUR INFORMATION 7. Jones B, Fishman EK, Hamilton SR, et al. Submucosal accumulation of fat in inflammatory bowel disease: T/pathologic correlation. J omput Assist Tomogr 1986; 10:759 763 8. Philpotts LE, Heiken JP, Westcott MA, Gore RM. olitis: use of T findings in differential diagnosis. Radiology 1994; 190:445 449 9. Gore RM, Balthazar EJ, Ghahremani GG, Miller FH. T features of ulcerative colitis and rohn s disease. AJR 1996; 167:3 15 10. Macari M, Balthazar EJ. T of bowel wall thickening: significance and pitfalls of interpretation. AJR 2001; 176:1105 1116 11. Harisinghani MG, Wittenberg J, Lee W, hen S, Gutierrez AL, Mueller PR. Bowel wall fat halo sign in patients without intestinal disease. AJR 2003; 181:781 784 12. Muldowney SM, Balfe DM, Hammerman A, Wick MR. Acute fat deposition in bowel wall submucosa: T appearance. J omput Assist Tomogr 1995; 19:390 393 13. hen S, Harisinghani MG, Wittenberg J. Small bowel T fat density target sign in chronic radiation enteritis. Australas Radiol 2003; 47:450 452 14. Green PH. The many faces of celiac disease: clinical presentation of celiac disease in the adult population. Gastroenterology 2005; 128[4 suppl 1]:S74 S78 15. National Institutes of Health onsensus Development onference Statement on eliac Disease, June 28 30, 2004. Gastroenterology 2005; 128[4 suppl 1]:S1 S141 The AJR has made getting the articles you really want really easy with a new online tool, Really Simple Syndication, available at www.ajronline.org. It s simple. lick the yellow RSS button located in the menu on the left of the page. You ll be on your way to syndicating your AJR content in no time. 790 AJR:189, October 2007