Minimization of radiation exposure due to computed tomography in inflammatory bowel disease

Radiation Exposure in Patients with Inflammatory Bowel Disease: a Fourteen-Year Review at a Tertiary Care Centre in Malaysia

Background and Aims:

Patients with inflammatory bowel disease (IBD) are subjected to a large amount of ionizing radiation during the course of their illness. This may increase their risk of malignancy to a greater level than that due to the disease itself. In Caucasian patients with Crohn’s disease, this has been well documented and recommendations are in place to avoid high radiation imaging protocols. However, there are limited data available on radiation exposure in Asian IBD patients. We therefore sought to identify total radiation exposure and any differences between ethnically diverse ulcerative colitis (UC) and Crohn’s disease (CD) patients at our centre along with determining factors that may contribute to any variation.

Methods:

The cumulative effective dose (CED) was calculated retrospectively from 2000 to 2014 using data from our online radiology database and patients’ medical records. Total CED in the IBD population was measured. High exposure was defined as a radiation dose of greater than 0.2mSv (equivalent to slightly less than ½ a year of background radiation).

Results:

A total of 112 cases of IBD (36 CD and 76 UC) were reviewed. Our CD patients were diagnosed at an earlier age than our UC cases (mean age 26.1 vs 45.7). The total CED in our IBD population was 8.53 (95% CI: 4.53-12.52). Patients with CD were exposed to significantly higher radiation compared to those with UC. The mean CED was 18.6 (7.30-29.87) and 3.65 (1.74-5.56, p=0.01) for CD and UC patients respectively. 2 patients were diagnosed as having a malignancy during follow up with respective CED values of 1.76mSv and 10mSv.

Conclusions:

CD patients, particularly those with complicated disease, received a higher frequency of diagnostic imaging over a shorter period when compared to UC patients. Usage of low radiation imaging protocols should be encouraged in IBD patients to reduce their risk of consequent malignancy.

Magnetic resonance imaging of the chest in the evaluation of cancer patients: state of the art

Magnetic resonance imaging (MRI) has several advantages in the evaluation of cancer patients with thoracic lesions, including involvement of the chest wall, pleura, lungs, mediastinum, esophagus and heart. It is a quite useful tool in the diagnosis, staging, surgical planning, treatment response evaluation and follow-up of these patients. In the present review, the authors contextualize the relevance of MRI in the evaluation of thoracic lesions in cancer patients. Considering that MRI is a widely available method with high contrast and spatial resolution and without the risks associated with the use of ionizing radiation, its use combined with new techniques such as cine-MRI and functional methods such as perfusion- and diffusion-weighted imaging may be useful as an alternative tool with performance comparable or complementary to conventional radiological methods such as radiography, computed tomography and PET/CT imaging in the evaluation of patients with thoracic neoplasias.

Diagnostic medical radiation in inflammatory bowel disease: how to limit risk and maximize benefit

Diagnosis and management of inflammatory bowel disease (IBD) requires repeat diagnostic imaging for monitoring of disease activity. Recent evidence has suggested that patients with IBD are at increased risk of radiation exposure from repeat imaging. The aim of this article was to highlight risks associated with increasing radiation exposure and identify alternatives to minimize exposure. The increasing use of computed tomography (CT) in both Crohn's disease and ulcerative colitis has brought additional benefits to guiding management through non-invasive measures. However, the massive increase in use of CT scans poses a risk of exposing patients with IBD to high levels of diagnostic medical radiation. High levels of diagnostic medical radiation are associated with an increased risk of malignancy in several studies. Numerous studies have identified particular risk factors in IBD associated with high levels of diagnostic medical radiation which are also associated with a more severe disease course. Imaging techniques such as magnetic resonance enterography, ultrasound, small bowel follow through, and capsule endoscopy are alternatives to CT scans as they do not utilize radiation. Gastroenterologists managing patients with IBD, particularly Crohn's disease, should be aware of the increased risk of high cumulative doses of radiation exposure, particularly from CT scanning. Alternative forms of imaging should be carefully considered when evaluating patients, in particularly those with identifiable risk factors for an aggressive disease course.

The impact of abdominal computed tomography in a tertiary referral centre emergency department on the management of patients with inflammatory bowel disease

BACKGROUND

Although exposure to diagnostic radiation may be associated with increased risk of malignancy, the use of abdominal CT (ACT) in the last decade has increased for patients in the emergency department (ED).

AIM

To examine the impact of ACT ordered in the ED on management of patients with inflammatory bowel diseases (IBD), as well as to quantify the cumulative effective dose (CED) of radiation received by these patients.

METHODS

A total of 152 patients with Crohn's disease (CD) and 130 patients with ulcerative colitis (UC) that presented to the ED in a tertiary centre between 2009 and 2011 were identified. For patients that had an ACT, chart review assessed if the ACT findings changed clinical management. CED of diagnostic radiation (DR) was calculated for all imaging studies between 1 January 2006 and 30 August 2012.

RESULTS

Abdominal CT use was 49% for CD and 19% for UC. ACTs with findings of penetrating/obstructive disease were 35% for CD. Urgent non-IBD-related diagnoses were found in 13% for CD and 28% for UC (P < 0.05). ACT caused a change in management in 81% of CD and 69% of UC patients. Mean CED from DR was 77.4 ± 63.0 mSv (median 53 mSv) for CD and 67.2 ± 51.0 mSv (median 56 mSv) for UC (P = 0.47). The CED for the 80-month period exceeded 75 mSv in 35% and 36% respectively (P = 0.99).

CONCLUSIONS

Although abdominal CT often changes management of IBD patients in the emergency department, this population carries a very high-risk of radiation exposure. Efforts should be made to decrease this risk by development of low-radiation protocols, and wider use of MRI/ultrasound.

Magnetic resonance enterography in Crohn's disease: a guide to common imaging manifestations for the IBD physician

Patients with Crohn's disease (CD) frequently require cross-sectional imaging. Magnetic resonance enterography (MRE) is an accurate tool for assessment of bowel disease and of various complications of CD. The lack of non-ionizing radiation exposure is an important advantage of this imaging modality. Familiarity with common and pathognomonic imaging features of CD is essential for every clinician that is involved in inflammatory bowel disease (IBD) patients' care. This review is aimed to describe the indications for performing MRE in CD, essentials of MRE techniques and typical radiological findings in patients with CD to aid the IBD doctor in daily practice.

Plain abdominal radiographs in patients with Crohn's disease: radiological findings and diagnostic value

AIM

To determine the diagnostic yield and clinical value of plain film of the abdomen (PFA) in Crohn's disease (CD) patients and to determine whether performance of PFA yields definitive diagnostic information or whether additional imaging examinations are required.

MATERIALS AND METHODS

One hundred and seventy-seven CD patients underwent 643 PFAs during the period September 1992 to August 2008. Two radiologists blinded to the clinical details independently evaluated individual PFAs and/or their reports for abnormal findings using the following criteria: normal, small bowel (SB) findings; colonic findings, acute CD complications, extra-colonic findings; global assessment/impression. The results of additional imaging studies performed within 5 days of PFA were recorded and findings were analysed.

RESULTS

A mean of 3.6 (range 1-22) PFAs was performed per patient during the study period. Almost 70% of films were normal (n = 449). SB abnormalities were detected in 21.8% (n = 140) PFAs; most commonly dilated loops (18.8%, n = 121) and mucosal oedema (5%, n = 32). Colonic abnormalities were present in 11.4% (n = 73); most commonly mucosal oedema (7.5%, n = 48) and dilated loops (5%, n = 32). Four cases of pneumoperitoneum were detected. There was no case of toxic megacolon. There was one case in which intra-abdominal abscess/collection was suspected and two cases of obstruction/ileus. Extracolonic findings (renal calculi, sacro-iliitis, etc.) were identified in 7.5% (n = 48). PFAs were followed by additional abdominal imaging within 5 days of PFA in 273/643 (42.5%) of cases.

CONCLUSION

Despite the high rates of utilization of PFA in CD patients, there is a low incidence of abnormal findings (32.5%). Many of the findings are non-specific and clinically irrelevant and PFA is frequently followed by additional abdominal imaging examinations.

Meta-analysis: diagnostic medical radiation exposure in inflammatory bowel disease

BACKGROUND

Diagnostic imaging plays a pivotal role in the diagnosis and management of inflammatory bowel disease (IBD); however, increasing use has led to concerns about the malignant potential of ionising radiation. Several studies have demonstrated that diagnostic imaging can result in exposure to potentially harmful levels of ionising radiation in IBD patients.

AIM

To determine the pooled prevalence of increased exposure and pooled odds ratio of risk factors associated with exposure to potentially harmful levels of diagnostic medical radiation.

METHODS

We searched Medline, EMBASE, CINHAL and reference lists of identified articles, without language restrictions in October 2011.

RESULTS

Six studies with 1704 participants provided data on the proportion of patients receiving potentially harmful levels of radiation defined as ≥50 milli-sieverts (mSv)-equivalent to 5 CT abdomen scans. The pooled prevalence was 8.8% (95% CI 4.4-16.8) for IBD patients and 11.1% (95% CI 5.7-20.5%) and 2% (95% CI 0.8-4.9%) for Crohn's disease and ulcerative colitis patients respectively. Five studies involving 2627 participants provided data for risk factors. IBD-related surgery and corticosteroid use were significant with pooled adjusted odds ratio of 5.4 (95% CI 2.6-11.2) and 2.4 (95% CI 1.7-3.4) respectively.

CONCLUSIONS

About 1 in 10 patients may be exposed to potentially harmful levels of diagnostic medical radiation. Corticosteroid use and IBD related surgery increased this risk. Strategies to reduce radiation exposure while assessing disease activity need to be considered.