Value of virtual computed tomographic colonography for Crohn's colitis: comparison with endoscopy and barium enema

Computed tomography colonography for the practicing radiologist: A review of current recommendations on methodology and clinical indications

Colorectal cancer (CRC) represents one of the most relevant causes of morbidity and mortality in Western societies. CRC screening is actually based on faecal occult blood testing, and optical colonoscopy still remains the gold standard screening test for cancer detection. However, computed tomography colonography (CT colonography) constitutes a reliable, minimally-invasive method to rapidly and effectively evaluate the entire colon for clinically relevant lesions. Furthermore, even if the benefits of its employment in CRC mass screening have not fully established yet, CT colonography may represent a reasonable alternative screening test in patients who cannot undergo or refuse colonoscopy. Therefore, the purpose of our review is to illustrate the most updated recommendations on methodology and the current clinical indications of CT colonography, according to the data of the existing relevant literature.

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.

Virtual colonoscopy: Utility, impact and overview

Computed tomography (CT) colonoscopy is a well-established technique for evaluation of colorectal cancer. Significant advances have been made in the technique of CT colonoscopy since its inception. Excellent results can be achieved in detecting both colorectal cancer and significant sized polyps as long as a meticulous technique is adopted while performing CT colonoscopy. Furthermore, it is important to realize that there is a learning curve involved in interpreting these studies and adequate experience is essential to achieve high sensitivity and specificity with this technique. Indications, contraindications, technique and interpretation, including potential pitfalls in CT colonoscopy imaging, are reviewed in this article. Recent advances and the current role of CT colonoscopy in colorectal cancer screening are also discussed.

Evidence-based clinical practice guidelines for Crohn's disease, integrated with formal consensus of experts in Japan

Crohn's disease is a disorder of unknown etiology and complicated pathogenesis. A substantial amount of evidence has accumulated recently and has been applied to clinical practice. The present guidelines were developed based on recent evidence and the formal consensus of experts relevant to this disease. Here we provide an overview of these guidelines, as follows. Target disease: Crohn's disease Users: Clinical practitioners in internal medicine, surgery, gastroenterology, and general practice Purpose: To provide appropriate clinical indicators to practitioners Scope of clinical indicators: Concept of Crohn's disease, epidemiology, classifications, diagnosis, treatment, follow up, and special situations Intervention: Diagnosis (interview, physical examination, clinical laboratory tests, imaging, and pathology) and treatment (lifestyle guidance, drug therapy, nutritional therapy, surgery, etc.) Outcome assessment: Attenuation of symptoms, induction and maintenance of remission, imaging findings, quality of life (QOL), prevention of complications and harm of therapy Methods for developing these guidelines: Described in the text Basis of recommendations: Integration of evidence level and consensus of experts Cost-benefit analysis: Not implemented Evaluation of effectiveness: Yet to be confirmed Status of guidelines: Updated version of the first Guidelines published in 2010 Publication sources: Printed publication available and electronic information in preparation Patient information: Not available Date of publication: October 2011 These guidelines were intended primarily to be used by practitioners in Japan, and the goal of these guidelines is to improve the outcomes of patients with Crohn's disease.

Initial experience with computed tomographic colonography applied for noncolorectal cancerous conditions

PURPOSE

The aim of this study was to asses retrospectively the performance of computed tomography colonography (CTC) for noncolorectal cancerous conditions.

MATERIAL AND METHODS

A total of 44 patients with non-colorectal cancerous conditions underwent CTC. We researched the indications for CTC or present illness and evaluated the CTC imaging findings. We assessed whether diagnosis by CTC reduced conventional colonoscopic examinations.

RESULTS

A total of 47 examinations were performed in 44 patients. The indications for CTC or a present illness were as follows: 15 patients with impossible or incomplete colonoscopy, 7 with diverticular disease, 6 with malignancy (noncolorectal cancer), 6 with Crohn's disease, 4 suspected to have a submucosal tumor on colonoscopy, 2 with ischemic colitis, and 4 with various other diseases. Colonic findings were diagnosed on CTC in 36 examinations, and extracolonic findings were identified in 35 of 44 patients. In all, 17 patients had undergone colonoscopy previously, 9 (52.9%) of whom did not require further colonoscopy by CTC. Five patients underwent colonoscopy after CTC.

CONCLUSION

The indications for CTC were varied for patients with noncolorectal cancerous conditions. CTC examinations could be performed safely. Unlike colonoscopy or CT without preparation, CTC revealed colonic and extracolonic findings and may reduce the indication of colonoscopy in patients with noncolorectal cancerous conditions.

Computed tomographic colonography

This article provides basic information about computed tomographic colonography (CTC) and reviews the preparation, methods, and tools required for the procedure. The clinical uses for CTC (screening/diagnosis of colon cancer and colonic obstruction) are outlined, and its accuracy and validity are compared with other diagnostic methods. A summary of the benefits and risks of the test are presented and the current practicalities for implementation are addressed.

Asian perspectives in the management of inflammatory bowel disease: findings from a recent survey

BACKGROUND AND AIM

The prevalence and incidence of inflammatory bowel disease (IBD) differs worldwide. While the prevalence of IBD has stabilized in Europe, the USA and Japan, an increasing trend has been observed in Asia. However, there are no data on the current clinical practice for the management of IBD in the region. The present study aims to investigate the number of existing and new cases of IBD and to understand the current practice of diagnosis and treatment of IBD in different Asian countries.

METHODS

A self-administered questionnaire, designed according to European and US guidelines, was distributed to IBD specialists throughout Asia. The questionnaire estimated the annual incidence of existing and new IBD cases in physicians' clinical practices and evaluated their procedures of diagnosis and preference for therapeutic treatment and maintenance treatment.

RESULTS

Eighty-seven questionnaires were received out of the 107 distributed. In the clinical practices of these 87 respondents, there were 502 existing and 73 new cases per year for ulcerative colitis (UC) and 202 existing and 32 new cases per year for Crohn's disease (CD). Colonoscopy and histology were the most commonly used methods for the diagnosis of UC and CD, but clinical practice regarding the diagnosis of IBD varied. The treatment of choice for mild-to-moderate UC and CD was 5-aminosalicylic acid (5-ASA), which is also the preferred choice for the maintenance treatment of UC and CD.

CONCLUSION

Clinical practice with regards to IBD diagnosis and management varies within Asia.5-ASA is the preferred treatment and maintenance therapy for mild-to-moderate IBD.

Role of 3.0-T MR colonography in the evaluation of inflammatory bowel disease

Conventional colonoscopy combined with histologic analysis represents the standard of reference for the evaluation of colorectal disease and is usually the initial examination in patients with a suspected or established diagnosis of inflammatory bowel disease (IBD). However, it is increasingly being recognized that colonoscopy is limited to providing information regarding mucosal alterations. Colonoscopy cannot help estimate the depth of involvement of colonic lesions and does not provide information regarding the presence of extraluminal complications such as abscesses or fistulas. Recent technologic advances in magnetic resonance (MR) imaging, with its high spatial and tissue resolution, have raised expectations as to the potential role of this modality in the evaluation of colonic lesions in patients with IBD, as either a complement or an alternative to colonoscopy. MR colonography allows the characterization of colonic changes in acute and chronic IBD and can depict a wide spectrum of related lesions, including ulcers, edema, wall thickening, hyperemia, and fistulas, as well as potential extraluminal complications. The bulk of available evidence indicates that MR colonography can be useful as a problem-solving tool in the evaluation of IBD, as an alternative to colonoscopy whenever tissue sampling is not required, and for the assessment of the entire colon in cases of incomplete colonoscopy.

Non-invasive techniques for assessing postoperative recurrence in Crohn's disease

Postoperative recurrence after ileo-colonic resection is a feature of Crohn's Disease (CD), almost 73% of patients show endoscopic recurrence at 1 year and 90% at 3 years. After surgical resection for CD, symptoms may be related to the surgical resection itself. Moreover, the development of an early severe endoscopic recurrence within 1 year represents a risk factor for early clinical recurrence. On the basis of these observations, the early detection and assessment of asymptomatic endoscopic recurrence may allow a timely and appropriate treatment of CD patients after ileo-colonic resection. At this purpose, conventional colonoscopy with ileoscopy currently represents the gold standard for assessing CD recurrence, graded according to the Rutgeerts' score. Lesions compatible with CD recurrence can be also detected by conventional radiology, including small bowel follow through and enema, both associated with a high radiation exposure. Due to the ineluctable course of CD after resection, and to the need of a proper follow up for assessing CD recurrence, several alternative, non invasive techniques have been searched in order to assess the post-operative recurrence, including: faecal alpha 1-antitrypsin clearance, faecal calprotectin, 99Tc-HMPAO scintigraphy, virtual colonoscopy, ultrasonography and, more recently, wireless capsule endoscopy (WCE) and Small Intestine Contrast Ultrasonography (SICUS). Among these, current evidences suggest that in experienced hands, ultrasound examination by SICUS represents a non-invasive technique useful for assessing recurrence in CD patients under regular follow up after surgery. The same findings are suggested for WCE, although the impact risk related to the recurrence or to the surgical anastomosis itself limits the use of this non-invasive technique for assessing CD recurrence after surgery.

Detection of inflammatory bowel disease: diagnostic performance of cross-sectional imaging modalities

Different cross-sectional imaging techniques can be used as a diagnostic tool for the evaluation of inflammatory bowel disease (IBD). In this report the diagnostic performances of ultrasonography, magnetic resonance imaging and computed tomography in the detection of IBD and the evaluation of known IBD are described, together with a short update on patient preparation and imaging technique of the respective modalities discussed.

CT colonography: current status and future promise

CT colonography (CTC) is an innovative technology that entails CT examination of the entire colon and computerized processing of the raw data after colon cleansing and colonic distention. CTC could potentially increase the screening rate for colon cancer because of its relative safety, relatively low expense, and greater patient acceptance, but its role in mass colon cancer screening is controversial because of its highly variable sensitivity, the inability to sample polyps for histologic analysis, and lack of therapeutic capabilities. This article reviews the CTC literature, including imaging and adjunctive techniques, radiologic interpretation, procedure indications, contraindications, risks, sensitivity, interpretation pitfalls, and controversies.

Colonography by CT, MRI and PET/CT combined with conventional colonoscopy in colorectal cancer screening and staging

Colorectal cancer (CRC) remains a leading cancer killer worldwide. But the disease is both curable and preventable at an early stage. Regular CRC cancer screening has been shown to reduce the risk of dying from CRC. However, the importance of large-scale screening is only now starting to be appreciated. This article reviews a variety of imaging procedures available for detecting ulcerative colitis (UC) and Crohn’s disease (CD), polyps and CRC in their early stage and also presents details on various screening options. Detecting, staging and re-staging of patients with CRC also require multimodality, multistep imaging approaches. Staging and re-staging with conventional colonoscopy (CC), computer tomography colonography (CTC), magnetic resonance colonography (MRC) and positron emission tomography/computer tomography colonography (PET/CTC) are of paramount importance in determining the most appropriate therapeutic method and in predicting the risk of tumor recurrence and overall prognosis. The advantages and limitations of these modalities are also discussed.

CT colonography: techniques, indications, findings

Computed tomographic colonography (CTC) is a minimally invasive technique for imaging the entire colon. Based on a helical thin-section CT of the cleansed and air-distended colon, two-dimensional and three-dimensional projections are used for image interpretation. Several clinical improvements in patient preparation, technical advances in CT, and new developments in evaluation software have allowed CTC to develop into a powerful diagnostic tool. It is already well established as a reliable diagnostic tool in symptomatic patients. Many experts currently consider CTC a comparable alternative to conventional colonoscopy, although there is still debate about its sensitivity for the detection of colonic polyps in a screening population. This article summarizes the main indications, the current techniques in patient preparation, data acquisition and data analysis as well as imaging features for common benign and malignant colorectal lesions.

Colonic perforation after computed tomographic colonography in a patient with fibrostenosing Crohn's disease

Computed tomographic colonography (CTC) offers great promise in the management of patients with disorders of the colon. Few complications have been reported with its use thus far. We describe herein a case of colonic perforation during CTC in a patient with active stenosing ileocolonic Crohn's disease. To our knowledge, this is the first reported case of CTC-related perforation in the setting of Crohn's disease, and the third reported perforation overall. Perforation likely occurred in this case due to barotrauma in the setting of colonic strictures and an inflamed, weakened colonic wall. Physician awareness of the increased risk of perforation with CTC in the setting of inflammatory and/or obstructive disease of the colon will allow for improved clinical decision-making in the care of these patients.

Colonografía tomográfica computarizada: aplicaciones, ventajas e inconvenientes

INTRODUCTION

Complete preoperative study of the colon is required in the management of colorectal cancer, due to the frequent association of primary colonic neoplasms with colonic adenomas (28%) and/or synchronous carcinomas (5%) of the colon. We present a series of patients who underwent computed tomographic colonography, the indications for this procedure, and the results.

PATIENTS AND METHODS

We performed a descriptive prospective study. Between May 2003 and August 2004, 50 computed tomographic colonographies were performed in 50 patients with suspected stenosing colorectal cancer and incomplete conventional colonoscopy.

RESULTS

Fifty computed tomographic colonographies were performed. The findings were as follows: three were normal (6%), and in the remainder, one was a false positive for a suspected neoplastic pelvic mass (3.125%) and two were false positives (11.7%) for colonic polyps. Fifty percent of the findings (n = 32) were related to peritoneal metastases and colonic neoplasms. There were 12 technical complications [lack of cleaning of the colon (5), lack of distension (2), little air insufflation (5)]. Patient complications included vegetative manifestations in one (vomiting) and rectal bleeding in another. The overall complication rate was 27.4% (23.4% corresponded to technical complications and the remaining 4% were patient-related). There was no mortality related to the procedure.

CONCLUSION

Because computed tomographic colonography is safe, effective and well tolerated by the patient, it should be considered as a technical alternative in the study of stenosing neoplasms of the proximal colon with incomplete colonoscopy. In addition, it allows other associated findings, both intra- and extracolonic, to be obtained and improves the diagnostic and therapeutic management of the patient.