Colonoscopy and technetium-99m white cell scan in children with suspected inflammatory bowel disease

Radiographical evaluation of ulcerative colitis

Radiographical modalities have become important diagnostic tools in cases of ulcerative colitis (UC). Imaging can be used non-invasively to determine the extent of involvement, severity of disease and to detect disease-related complications and extra-intestinal inflammatory bowel disease (IBD) manifestations. While abdominal X-rays and barium enemas still retain their relevance in specific clinical settings, the use of computed tomography enterography (CTE) or magnetic resonance enterography (MRE) are now used as first-line investigations to exclude active small bowel disease in IBD patients and can be utilized to detect active colonic inflammation. Additionally, CT colonography and MR colonography are emerging techniques with potential applications in UC. Ultrasonography, leukocyte scintigraphy and positron emission tomography are novel abdominal imaging modalities currently being explored for IBD interrogations. This plethora of radiological imaging options has become a vital component of UC assessments.

Results of the 2nd part Scientific Workshop of the ECCO. II: Measures and markers of prediction to achieve, detect, and monitor intestinal healing in inflammatory bowel disease

The healing of the intestine is becoming an important objective in the management of inflammatory bowel diseases. It is associated with improved disease outcome. Therefore the assessment of this healing both in clinical studies and routine practice is a key issue. Endoscopy for the colon and terminal ileum and computerized tomography or magnetic resonance imaging for the small bowel are the most direct ways to evaluate intestinal healing. However, there are many unsolved questions about the definition and the precise assessment of intestinal healing using these endoscopic and imaging techniques. Furthermore, these are relatively invasive and expensive procedures that may be inadequate for regular patients' monitoring. Therefore, biomarkers such as C-reactive protein and fecal calprotectin have been proposed as surrogate markers for intestinal healing. Nevertheless, the sensitivity and specificity of these markers for the prediction of healing may be insufficient for routine practice. New stool, blood or intestinal biomarkers are currently studied and may improve our ability to monitor intestinal healing in the future.

Role of scintigraphy in inflammatory bowel disease

The diagnosis of inflammatory bowel disease (IBD) depends on direct endoscopic visualization of the colonic and ileal mucosa and the histological study of the obtained samples. Radiological and scintigraphic methods are mainly used as an adjunct to endoscopy. In this review, we focus on the diagnostic potential of nuclear medicine procedures. The value of all radiotracers is described with special reference to those with greater experience and more satisfactory results. Tc-99m hexamethylpropylene amine oxime white blood cells remain a widely acceptable scintigraphic method for the diagnosis of IBD, as well as for the evaluation of disease extension and severity. Recently, pentavalent Tc-99m dimercaptosuccinic acid has been recommended as an accurate variant and a complementary technique to endoscopy for the follow-up and assessment of disease activity. Positron emission tomography alone or with computed tomography using fluorine-18 fluorodeoxyglucose appears to be a promising method of measuring inflammation in IBD patients.

Role of MRI in Crohn's disease

The traditional imaging of Crohn's disease has relied on barium and computed tomography (CT) examinations. In recent years magnetic resonance imaging (MRI) has emerged as an imaging method that can be used in the diagnosis and assessment of Crohn's disease. The advantages of MRI include lack of ionizing radiation and its superior tissue contrast resolution. The clinical progression of Crohn's disease can be variable, and MRI can be used to assess inflammatory status, disease progression, and complications of Crohn's disease. MRI of the small bowel is an evolving technique and it has the potential to become the preferred technique for imaging of small bowel Crohn's disease in the future.

Inflammatory bowel disease diagnosed with US, MR, scintigraphy, and CT: meta-analysis of prospective studies

PURPOSE

To compare, by performing a meta-analysis, the accuracies of ultrasonography (US), magnetic resonance (MR) imaging, scintigraphy, computed tomography (CT), and positron emission tomography (PET) in the diagnosis of inflammatory bowel disease (IBD).

MATERIALS AND METHODS

MEDLINE, EMBASE, CINAHL, and Cochrane databases were searched for studies on the accuracy of US, MR imaging, scintigraphy, CT, and PET, as compared with a predefined reference standard, in the diagnosis of IBD. Sensitivity and specificity estimates were calculated on per-patient and per-bowel-segment bases by using a bivariate random-effects model.

RESULTS

Thirty-three studies, from a search that yielded 1406 articles, were included in the final analysis. Mean sensitivity estimates for the diagnosis of IBD on a per-patient basis were high and not significantly different among the imaging modalities (89.7%, 93.0%, 87.8%, and 84.3% for US, MR imaging, scintigraphy, and CT, respectively). Mean per-patient specificity estimates were 95.6% for US, 92.8% for MR imaging, 84.5% for scintigraphy, and 95.1% for CT; the only significant difference in values was that between scintigraphy and US (P = .009). Mean per-bowel-segment sensitivity estimates were lower: 73.5% for US, 70.4% for MR imaging, 77.3% for scintigraphy, and 67.4% for CT. Mean per-bowel-segment specificity estimates were 92.9% for US, 94.0% for MR imaging, 90.3% for scintigraphy, and 90.2% for CT. CT proved to be significantly less sensitive and specific compared with scintigraphy (P = .006) and MR imaging (P = .037)

CONCLUSION

No significant differences in diagnostic accuracy among the imaging techniques were observed. Because patients with IBD often need frequent reevaluation of disease status, use of a diagnostic modality that does not involve the use of ionizing radiation is preferable.

Wireless capsule endoscopy in children: a study to assess diagnostic yield in small bowel disease in paediatric patients

BACKGROUND AND AIM

Small bowel disease in the paediatric population is varied and to date has relied on indirect l modalities such as small bowel follow-through with attendant radiation exposure. Wireless capsule endoscopy (WCE) has the potential to provide a safer and more effective means of investigating the paediatric small bowel. The aim of our study was to prospectively assess the diagnostic yield of WCE compared with standard investigation in children with suspected small bowel disease.

METHODS

Twenty-eight consecutive patients, median age 12.5 y (range, 9.4-15.9) with suspected small bowel disease were investigated with WCE. This included 16 patients with suspected small bowel Crohn disease (CD) (10 newly diagnosed; 6 known cases), 6 with obscure or occult gastrointestinal bleeding (GIB), 3 with Peutz-Jegher polyposis (PJP), 2 with protein-losing enteropathy and 1 with recurrent abdominal pain. All of the patients had preceding upper gastrointestinal endoscopy (OGD) and ileocolonoscopy, and 24 had a barium meal and follow-through (BMFT). Images were downloaded and analysed and results compared with the endoscopic and radiological findings.

RESULTS

Three patients were unable to swallow the capsule (1 CD, 1 PJP and 1 GIB). Two of these patients (1 GIB, 1 PJP) had the capsule placed in the stomach endoscopically and completed the WCE uneventfully thereafter. In 3 patients (CD group) the capsule remained in the stomach and/or proximal duodenum and no small bowel images were obtained. Hence, 24 patients had successful completion of the WCE through the small bowel, 23 of whom had clinically relevant findings identified. In all patients with CD who had successful WCE studies (12/16), small bowel disease was identified (11/12 active disease, 1/12 chronic disease). A possible small bowel bleeding source was identified in all 6 patients with GIB. Two patients with GIB also underwent push enteroscopy and 1 of these had a bleeding source identified. The 2 patients with protein-losing enteropathy had extensive patchy lymphangiectasia of the jejunum and ileum, not detected at OGD. The patient with abdominal pain had an intussusception of the upper jejunum. The 2 PJP patients had small bowel polyps identified, which were not detected at BMFT. WCE was more sensitive for small bowel pathology than both BMFT (19 vs 5; 26% sensitivity compared with WCE) and endoscopic investigations (23 vs 10; 43.4% sensitivity compared with WCE). Two patients with CD had delayed capsule transit.

CONCLUSIONS

WCE led to a positive alteration in management in 18/24 (75%) of patients whose small bowel was examined by WCE and in 18/28 (64.3%) who were admitted to the study. WCE was safe, well tolerated, and more sensitive than radiological and standard endoscopic modalities in the detection of small bowel CD distribution, GIB source, and presence of polyps in children.

Nuclear medicine imaging of inflammatory/infective disorders of the abdomen

Different nuclear medicine modalities are currently used to study inflammatory and infective disorders of the abdomen. They are usually complementary to radiology and endoscopy, but they play a pivotal role in particular clinical situations. Several radiopharmaceuticals (e.g., 111In or 99mTc labelled white blood cells, monoclonal antibodies, human polyclonal immunoglobulins, 75Ga citrate) are commercially available, but they can not be used indifferently to study abdominal inflammatory disorders. The lack of comparative studies showing the accuracy of each radiopharmaceutical for the study of inflammatory/infective abdominal diseases does not allow the best nuclear medicine technique(s) to be chosen in an evidence-based manner. To this end we performed a meta-analysis of peer reviewed articles published between 1984 and 2004 describing the use of nuclear medicine imaging for the study of inflammatory bowel disorders, appendicitis and vascular graft infections. A guideline for the optimal radiopharmaceutical(s) to be used in each clinical condition and for different aims is provided.

Positron emission tomography in the investigation of pediatric inflammatory bowel disease

BACKGROUND

Endoscopic and radiologic studies are frequently required in inflammatory bowel disease (IBD) to determine disease activity, extent of disease, and delineating disease type. Positron emission tomography (PET) using fluorine-18-fluoro-deoxyglucose to identify metabolically active tissues may offer a simple noninvasive alternative to conventional studies in identification and localization of active intestinal inflammation in children with IBD. The aim of this study was to assess the value of PET in identifying active intestinal inflammation compared with conventional endoscopic and radiologic studies, including small bowel follow-through and colonoscopy.

METHODS

Sixty-five children were enrolled in the study. This included 55 children (mean age, 13.3 yr; range, 7-18 yr; 20 girls) with newly diagnosed IBD (37) or symptoms suggestive of recurrent disease (18) and 10 children with recurrent abdominal pain (mean age, 12.7 yr; range, 8-15 yr; 7 girls) who were studied with PET, and the results were compared with small bowel follow-through with pneumocolon and/or colonoscopy. Thirty-eight patients had Crohn's disease (17 ileal, 12 ileocolic, 5 pancolonic, 3 left-sided disease, 1 right-sided disease), and 17 had ulcerative colitis (15 pan-colitis, 2 left-sided colitis). Mean time interval between PET and other studies was 30 +/- 17.6 days.

RESULTS

PET correctly identified active inflammatory disease in 80% of children with IBD (81.5% with Crohn's disease; 76.4% with ulcerative colitis) and correctly showed no evidence of inflammation in children with recurrent abdominal pain. Gluorine-18-fluoro-deoxyglucose accumulated at sites that corresponded with active disease at colonoscopy in 83.8% of patients and with small bowel follow-through with pneumocolon 75.0% of the time.

CONCLUSION

This study suggests that PET offers a noninvasive tool for identifying and localizing active intestinal inflammation in children with IBD. PET may not be able to replace conventional studies; however, it may be useful when conventional studies cannot be performed or fail to be completed.

Noninvasive diagnosis of small bowel Crohn's disease: combined use of bowel sonography and Tc-99m-HMPAO leukocyte scintigraphy

BACKGROUND

Crohn's disease (CD) is frequently localized in the small bowel, with the diagnosis of disease and the assessment of its extension made by ileo-colonoscopy (IC) and small bowel enteroclysis (SBE). Transabdominal bowel sonography (BS) and Tc-99m-HMPAO leukocyte scintigraphy (LS) are increasingly used for the diagnosis of CD because of their minimal invasiveness, reproducibility, and acceptable costs.

METHODS

From March 2000 to July 2003, we performed IC, SBE, BS, and LS in 84 patients with either suspected or known small bowel CD.

RESULTS

Small bowel CD was present in 50 patients, whereas the other 34 patients received a different diagnosis. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy were, respectively, 98%, 97%, 98%, 97%, and 0.97 for SBE; 92%, 97%, 98%, 88%, and 0.94 for BS; and 90%, 93%, 96%, 85%, and 0.92 for LS. In addition, the combined use of BS and LS led to overall sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy of 100%, 93%, 96%, 100%, and 0.97, respectively. BS showed a fair concordance with SBE in terms of location (k = 0.71) and a correlation with the extension of the disease (r = 0.67, P < 0.001). LS showed a concordance with SBE with regard to location in about one-half the population (k = 0.54), whereas it was less effective than SBE in defining disease extension.

CONCLUSIONS

BS and LS are 2 accurate techniques for the diagnosis of small bowel CD, and their combined use can be recommended as an early diagnostic approach to patients in which the disease is suspected. SBE remains the best procedure for the definition of the location and extension of the disease.

Etiopathogenesis of inflammatory bowel disease: the importance of the pediatric perspective

Inflammatory bowel disease (IBD) is now recognized as a common chronic disease affecting children and adolescents. This article will review recent advances made in the fields of genetics, epidemiology, gut ecology, and immunology regarding the etiopathogenesis of IBD, with particular emphasis on the contributions made by pediatric studies. Areas where further study of the pediatric age group would be beneficial will be highlighted.

99mTc-HMPAO leucocyte scintigraphy fails to detect Crohn's disease in the proximal gastrointestinal tract

OBJECTIVE

To investigate the use of (99m)Tc-HMPAO (hexamethyl propylene amine oxime) leucocyte scintigraphy as a non-invasive screening test for inflammatory bowel disease.

PATIENTS

10 children with suspected Crohn's disease, in whom routine investigation using barium contrast radiology, upper gastrointestinal endoscopy, colonoscopy, and mucosal biopsies had identified severe gastroduodenal and/or jejunal involvement.

DESIGN

(99m)Tc-HMPAO leucocyte scintigraphic studies performed in each of these cases were assessed by a radiologist who was blinded to the disease distribution.

RESULTS

In nine cases there was no scintigraphic evidence of inflammation in the proximal gastrointestinal tract. The 10th child had both gastroduodenal and jejunal involvement, but scintigraphy only revealed faint jejunal positivity.

CONCLUSIONS

(99m)Tc-HMPAO leucocyte scintigraphy should not be depended upon as a screening test for Crohn's disease. False negative results are likely in cases with Crohn's disease confined to the proximal gastrointestinal tract.

A Perspective on inflammatory bowel disease in the child and adolescent at the turn of the millennium

The literature of the past year has produced significant advances relevant to the diagnosis and treatment of children and adolescents with inflammatory bowel disease. This review focuses on new observations regarding the epidemiology, genetics, etiology, diagnosis, and treatment of both Crohn's disease and ulcerative colitis in children. Particular attention is paid to the expanded indications for the use of immunomodulatory therapy, and to the early published data regarding the safety and efficacy of treatment with infliximab.

Technetium-99m HMPAO-labeled leukocyte imaging compared with endoscopy, ultrasonography, and contrast radiology in children with inflammatory bowel disease

BACKGROUND

The purpose of this study was to evaluate retrospectively the value of leukocyte-labeled scintigraphy, ultrasonography, and contrast radiography compared with endoscopy in children suspected of having inflammatory bowel disease (IBD).

METHODS

Twenty-eight children (17 boys; mean age, 10.2 years) with IBD based on standard colonoscopic, histologic, and radiologic criteria (16 with Crohn's disease, 5 with ulcerative colitis, 5 with nonspecific colitis, I with granulomatous disease, and I with Beh,cet's disease) were included. Endoscopic, ultrasonographic, and contrast radiologic examinations were realized for 28, 23, and 19 children respectively.

RESULTS

Sensitivity and specificity were 75% and 92% for leukocyte-labeled scintigraphy, 39% and 90% for ultrasonography, and 58% and 83% for contrast radiography. The authors noted discontinuous uptake for 14 of 15 true-positive results for patients with Crohn's disease and continuous uptake for 4 of 4 true-positive results for patients with ulcerative colitis. A negative correlation between scan activity index and Lloyd-Still clinical score was found for 11 patients with Crohn's disease (r = -0.77).

CONCLUSIONS

Leukocyte-labeled scintigraphy, a noninvasive and reproducible technique, is a useful tool in the diagnosis and therapeutic strategy of IBD, and provides information on the presence, the intensity, and the extent of the disease, particularly in the terminal ileum. Leukocyte-labeled scintigraphy may not replace colonoscopy with biopsies for diagnosis confirmation. Its reliability seems higher than that of ultrasonography.

Inflammatory bowel disease

Till about 3 decades ago, inflammatory bowel disease (IBD) was considered as non-existent in our country. However, since that time several reports of IBD, mainly ulcerative colitis have been published. More recently, Crohn's disease is also being reported from the country. This trend of UC appearing first in a population followed by CD also appears to be true in other developing nations. A substantial increase in the rates of CD over UC in the last few decades is reported from developed nations as well. Of the other epidemiological factors, an increased risk of CD and lower risk of UC in smokers is established in adults. However, it appears that smoking increases the risk of IBD in children. The etiology of IBD remains elusive. Within the triad of genetics, immunity and antigen responsible for the development of IBD, maximum advances have been made in the field of immune aberrations and this is being exploited to treat the disease. It is well established that IBD results from a disordered immune system in the gut, in response to an unidentified antigen in a predisposed individual. The immune response is enhanced and revolves around antigen-presenting cells, CD 4 T-lymphocytes and tumor necrosis factor alpha. CD results from an enhanced Th1 activity. The pathogenesis of UC is less clear but appears to be humoral. Advances in diagnostics include the availability of serology, ultrasound and nuclear scans, none of which have been tried in our setting where infectious diseases and tuberculosis is rampant. Growth failure and the importance of nutrition in IBD, especially CD, cannot be underemphasized. In many situations nutritional interventions have been used solely as a form of therapy for CD. Newer steroid molecules with minimal systemic effects are also being considered. Other treatment options highlighted are the use of immunosuppressive agents, biologic agents and role of surgery.