Low-dose CT Using Iterative Reconstruction in Patients With Inflammatory Bowel Disease

Ulcerative Colitis Clinical Trial

Clinical Trial Details — Status: Unknown status

Administrative data

• NCT number: NCT01244386
• Other study ID #: 10-CT-Crohn's
• Status: Unknown status
• Phase: N/A
• First received: November 18, 2010
• Last updated: November 18, 2010
• Start date: June 2010
• Est. completion date: December 2011

Study information

• Verified date: November 2010
• Source: University College Cork
• Contact: Michael M Maher, MD
• Phone: +353 86 1731929
• Email: m.maher[@]ucc.ie
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

The purpose of this study is to validate the use of a low-dose computed tomography (CT) protocol and facilitate reduced radiation doses in patients with inflammatory bowel disease (IBD). This is to be achieved using new computer software (Iterative Reconstruction and Automatic Tube Modulation) which will enable low-dose CT imaging at doses equivalent to that of an abdominal radiograph.

Description:

The increasing use of CT has prompted the development of new scanning protocols which reduce radiation doses to patients and minimise the likelihood of radiation related morbidity. The use of disease specific low-dose CT examinations is an emerging method of limiting radiation doses.

Research conducted in Cork University Hospital(CUH) by the current authors has identified a pressing need to reduce radiation doses in patients with IBD. A retrospective study of radiation doses in patients with Crohn's disease demonstrated that increasing numbers of CT exams are performed with average cumulative effective doses rising from 7.9 to 25mSv when the first 5-years of the 15 year study period were compared with the final 5-years. Eight-five percent of the dose during the final 5-year period was due to CT. Younger patients with more severe disease requiring surgery or steroids were more likely to undergo an increased number of exams. 15.5% of patients received cumulative effective doses of greater than 75mSv. This quantity of radiation exposure is associated with a 7.3% increase in mortality from cancer. In addition, patients with Crohn's disease are inherently predisposed to gastrointestinal and hepatobiliary carcinoma and small bowel lymphoma.

As an alternative to CT, IBD patients are frequently imaging with conventional abdominal radiography. The effective dose of a conventional abdominal radiograph (CAR) is approximately 10% that of a standard abdominal CT varying between 0.7 -0.1mSv. The current authors have also investigated the value of CAR. We retrospectively examined over 500 CAR's performed over a 16 year period in patients with IBD. Patients had an average of 3.5 CAR's performed but there were positive findings in less than 30% of exams. Many of these findings were non-specific requiring further investigation. For example separation of bowel loops on a plain radiograph has a wide differential diagnosis including abscess formation, presence of a phlegmonous mass, fibrofatty proliferation, bowel wall thickening and lymphadenopathy.

Patients with inflammatory bowel disease referred to CUH will undergo a modified abdominal CT protocol. The radiation dose of a standard CT abdomen and pelvis will be divided into 2 quotients. Patients will have a low-dose CT scan requiring approximately 10% of the dose of a standard abdominal CT. This equates to the radiation dose of a conventional abdominal radiograph. Patients will be imaged with a second CT exam using 90% of the standard abdominal CT dose ensuring a diagnostic study is acquired. Patients will be given oral and intravenous contrast agents as for a standard CT. Patients will have a C-reactive protein measured on the day of CT and will have their heights and weights also measured at the time of scanning. Patients will have a plain film of abdomen performed prior to CT.

Recruitment information / eligibility

• Status: Unknown status
• Enrollment: 250
• Est. completion date: December 2011
• Est. primary completion date: December 2011
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Adult patients requiring a CT abdomen for clinical purposes will be included

Exclusion Criteria:

• Pediatric patients

Related Conditions & MeSH terms

• Colitis, Ulcerative
• Crohn Disease
• Crohn's Disease
• Inflammatory Bowel Disease
• Inflammatory Bowel Diseases
• Intestinal Diseases
• Ulcerative Colitis

Locations

Country	Name	City	State
Ireland	Cork University Hospital	Cork	Co Cork

Sponsors (1)

Lead Sponsor	Collaborator
University College Cork

Country where clinical trial is conducted

Ireland, 

References & Publications (5)

Desmond AN, O'Regan K, Curran C, McWilliams S, Fitzgerald T, Maher MM, Shanahan F. Crohn's disease: factors associated with exposure to high levels of diagnostic radiation. Gut. 2008 Nov;57(11):1524-9. doi: 10.1136/gut.2008.151415. Epub 2008 Apr 28. — View Citation

Kalra MK, Maher MM, Rizzo S, Kanarek D, Shepard JA. Radiation exposure from chest CT: issues and strategies. J Korean Med Sci. 2004 Apr;19(2):159-66. Review. Erratum in: J Korean Med Sci. 2004 Jun;19(3):487. Shephard JA [corrected to Shepard JA]. — View Citation

Kalra MK, Rizzo S, Maher MM, Halpern EF, Toth TL, Shepard JA, Aquino SL. Chest CT performed with z-axis modulation: scanning protocol and radiation dose. Radiology. 2005 Oct;237(1):303-8. — View Citation

Kalra MK, Wittram C, Maher MM, Sharma A, Avinash GB, Karau K, Toth TL, Halpern E, Saini S, Shepard JA. Can noise reduction filters improve low-radiation-dose chest CT images? Pilot study. Radiology. 2003 Jul;228(1):257-64. Epub 2003 May 15. — View Citation

O'Connor OJ, Vandeleur M, McGarrigle AM, Moore N, McWilliams SR, McSweeney SE, O'Neill M, Ni Chroinin M, Maher MM. Development of low-dose protocols for thin-section CT assessment of cystic fibrosis in pediatric patients. Radiology. 2010 Dec;257(3):820-9. doi: 10.1148/radiol.10100278. Epub 2010 Sep 27. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	The adequacy of low dose CT in patients with Inflammatory bowel disease compared with standard dose CT	Radiation dose of a standard CT abdomen and pelvis will be divided into 2 quotients. A low-dose CT scan acquired using automatic tube current modulation (ATM) requiring 10% the dose of a standard abdominal CT and equating to that of a conventional abdominal radiograph. High noise index will be used ensuring reduced mAs. Increased image noise will be overcome by the IR filter. A second CT using 90% of the standard abdominal CT dose will ensure a diagnostic study is acquired.	At the time of CT
Secondary	The correlation of C-reactive protein assay with CT disease severity in inflammatory bowel disease.	The severity of inflammatory bowel disease will also be quantified based on the CT appearances. The disease severity as measured by CT will be correlated with C-reactive protein measured on the day of imaging.	CRP sample on same day as CT