Factors associated with radiation exposure in patients with inflammatory bowel disease

Casual associations of thyroid function with inflammatory bowel disease and the mediating role of cytokines

Background

Previous observational epidemiological studies have suggested a potential association between thyroid function and inflammatory bowel disease (IBD). However, the findings remain inconclusive, and whether this association is causal remains uncertain. The objective of this study is to investigate the causal association between thyroid function and IBD.

Methods

Genome-wide association studies (GWAS) involving seven indicators of thyroid function, IBD, and 41 cytokines were analyzed. Bidirectional two-sample Mendelian randomization (MR) and multivariable MR were conducted to examine the causal relationship between thyroid function and IBD and to explore the potential mechanisms underlying the associations.

Results

Genetically determined hypothyroidism significantly reduced the risk of CD (odds ratio [OR] = 0.761, 95% CI: 0.655-0.882, p < 0.001). Genetically determined reference-range TSH was found to have a suggestive causal effect on IBD (OR = 0.931, 95% CI: 0.888-0.976, p = 0.003), (Crohn disease) CD (OR = 0.915, 95% CI: 0.857-0.977, p = 0.008), and ulcerative colitis (UC) (OR =0.910, 95% CI: 0.830-0.997, p = 0.043). In reverse MR analysis, both IBD and CD appeared to have a suggestive causal effect on the fT3/fT4 ratio (OR = 1.002, p = 0.013 and OR = 1.001, p = 0.015, respectively). Among 41 cytokines, hypothyroidism had a significant impact on interferon-inducible protein-10 (IP-10) (OR = 1.465, 95% CI: 1.094-1.962, p = 0.010). The results of multivariable MR showed that IP-10 may mediate the causal effects of hypothyroidism with CD.

Conclusion

Our results suggest that an elevated TSH level reduces the risk of CD, with IP-10 potentially mediating this association. This highlights the pituitary-thyroid axis could serve as a potential therapeutic strategy for CD.

Molecular Imaging in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD) are chronic immune-mediated inflammatory diseases affecting the gastrointestinal tract. Classically, two subtypes of IBD are recognized: Ulcerative colitis and Crohn's disease. There is not a single and reliable test for IBD diagnosis but the nuclear medicine techniques like ^99mTc-HMPAO autologous labelled leukocytes scintigraphy (WBCS) and PET/CT plays a role in the management of IBD. Leukocytes can be labelled "in vitro" (using ^99mTc-HMPAO in Europe or ¹¹¹In-oxine in America) or "in vivo" using antigranulocyte monoclonal antibodies. Nuclear medicine techniques are not the first choice to investigate IBD. Ultrasonography and magnetic resonance (radiation free) are probably the first option, and the diagnosis is commonly established by endoscopic biopsies. Nevertheless, WBCS is highly sensitive and accurate and represent a real option when other methods cannot used for whatever reason. In fact, a normal scan discards the presence of active IBD. The test is also useful to measure the extension and severity of the diseases and to evaluate the response to treatment. PET/CT imaging using ¹⁸F-FDG has recently been introduced and studied in both children and adults showing an excellent sensitivity for detecting active intestinal inflammation, but poor specificity in some studies. PET alone appears to be sufficient for the evaluation of ulcerative colitis, but PET/CT provides considerably more information than PET alone in the evaluation of Crohn's disease. Current clinical applications of PET in IBD include its use in the early evaluation of IBD, especially in children who may not tolerate an invasive test such as colonoscopy. Many questions remain to be answered, but PET appears to be a promising tool in the non-invasive evaluation of IBD. On the other hand, PET/MR could become in the near future a powerful tool in the evaluation of IBD patients. In addition, immuno-PET with antibodies targeting innate immune markers is also being investigated to detect colonic inflammation. The development of these technologies in humans could offer a less invasive method than endoscopy for the diagnosis and monitoring of IBD.

10-Year Trend of Abdominal Magnetic Resonance Imaging Compared With Abdominal Computed Tomography Scans in Inflammatory Bowel Disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) frequently undergo multiple computed tomography (CT) examinations. With the widespread availability of magnetic resonance imaging (MRI), it is unclear whether the use of CTs in IBD has declined. We aimed to analyze the trends of CT and MRI use in a large cohort of IBD patients in a 10-year period.

METHODS

We retrospectively analyzed adults ≥18 years of age using a de-identified database, IBM Explorys. Patients with ≥1 CT of the abdomen (± pelvis) or MRI of the abdomen (± pelvis) at least 30 days after the diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) were included. We examined the factors associated with patients undergoing multiple CTs (≥5 CTs of the abdomen) and performed a trend analysis from 2010 to 2019.

RESULTS

Among 176 110 CD and 143 460 UC patients, those with ≥1 CT of the abdomen annually increased from 2010 to 2019 with mean annual percentage change of +3.6% for CD and +4.9% for UC. Similarly, annual percentage change for patients with ≥1 MRI (CD: +15.6%; UC: +22.8%) showed a rising trend. There was a 3.8% increase in CD patients receiving ≥5 CTs of the abdomen annually compared with a 2.4% increase among UC patients in the 10-year period. Age ≥50 years, men, African Americans, public insurance payors, body mass index ≥30kg/m2, and smoking history were associated with ≥5 CTs.

CONCLUSIONS

There is a considerable increase in the number of CT scans performed in IBD patients. Further studies can explore factors influencing the use of CT and MRI of the abdomen in IBD patients.

Less Emergency Department Abdominopelvic Computed Tomography for Patients With Crohn's Disease: A New Scoring System

BACKGROUND

In recent years, the use of abdominal pelvic computed tomography (APCT) in the emergency department (ED) for patients with Crohn's disease (CD) has risen steadily. Thus, exposing these patients to recurrent radiation, despite studies showing that only 30% to 40% had significant findings in ED APCT.

GOAL

Our aim was to find clinical and laboratory variables that can predict substantial findings on ED APCT, which may require invasive intervention.

METHODS

We analyzed ED visits of patients with known CD that underwent an emergent APCT for gastrointestinal complaints, over a 10-year period. Patients with positive and negative findings in the APCT were compared in order to evaluate independent effects of different variables, including patients' characteristics, CD history, ED complaints, and laboratory tests.

RESULTS

In 44% of 183 ED visits, there were significant findings on ED APCT, however, only 22% of them underwent invasive intervention. Laboratory tests: C-reactive protein >50 mg/L, neutrophil count >75%, platelet count >350×10 9 /L, and ileocolon location at diagnosis were all positive predicting factors. Whereas, smoking or ED complaints of diarrhea/fever reduced the risk for significant findings.

CONCLUSIONS

Using the 7 most significant predicting factors, we built an easy to use scoring system-Crohn Assessment Tool for CT upon Hospitalization (CATCH) for ED clinicians. This scoring system could have prevented unnecessary ED APCT from 42% of the patients in our study, without missing those who required invasive intervention.

Radiation Exposure among Patients with Inflammatory Bowel Disease: A Single-Medical-Center Retrospective Analysis in Taiwan

Inflammatory bowel disease (IBD) is a chronic and relapsing disease that can be complicated by abscesses, fistulas, or strictures of the damaged bowel. Endoscopy or imaging studies are required to diagnose and monitor the treatment response or complications of the disease. Due to the low incidence of the disease in Taiwan, the pattern of radiation exposure from medical imaging has not been well studied previously. This retrospective study aimed to evaluate the pattern of radiation exposure in 134 Taiwanese IBD patients (45 CD and 89 UC) diagnosed and followed at Changhua Christian Hospital from January 2010 to December 2020. We reviewed the patient demographic data and radiation-containing image studies performed during the follow-up. The cumulative effective dose (CED) was calculated for each patient. During a median follow-up of 4 years, the median CED was higher for patients with CD (median CED 21.2, IQR 12.1−32.8) compared to patients with UC (median CED 2.1, IQR 0−5.6) (p < 0.001). In addition, the CD patients had a trend of a higher rate of cumulative ≥50 mSv compared with the UC patients (6.7% vs. 1.1%, p = 0.110). In conclusion, our study found a higher radiation exposure among CD patients compared to patients with UC, representing the complicated nature of the disease. Therefore, increasing the use of radiation-free medical imaging such as intestinal ultrasound or magnetic resonance imaging should be advocated in daily practice to decrease the risk of excessive radiation exposure in these patients.

Cumulative Effective Dose from Medical Imaging in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD) are chronic and relapsing disorders usually requiring numerous medical imaging. IBD patients might be exposed to a large dose of radiation. As a cumulative effective dose (CED) ≥ 50 mSv is considered significant for stochastic risks of cancer, it is important to monitor the radiation exposure of IBD patients. In the present work, we aimed to quantify the mean CED in IBD patients and identify factors associated with exposure to high doses of diagnostic radiation. A retrospective chart view of patients with IBD hospitalized between 2015 and 2019 was performed. A total of 65 patients with Crohn's disease (CD) and 98 patients with ulcerative colitis (UC) were selected. Of all imaging studies performed, 73% were with doses of ionizing radiation. Mean CED (SD) amounted to 19.20 (15.64) millisieverts (mSv) and 6.66 (12.39) mSv, respectively, in patients with CD and UC (p < 0.00001). Only 1.84% of the patients received CED ≥ 50 mSv. We identified three factors associated with CED in the IBD patients: number of surgical procedures, and number and length of hospitalization. CD patients with strictures or penetrating disease and UC patients with extensive colitis were more likely to receive higher radiation doses.

Flattening in the Anteroposterior Direction of the Terminal Ileum or Sigmoid Colon Lying Across the Psoas Muscle on Magnetic Resonance Enterography in Patients with Crohn's Disease

OBJECTIVE

Flattening in the anteroposterior direction (AP flattening) of the terminal ileum (TI) or sigmoid colon (SC) lying across the psoas muscle, on magnetic resonance enterography (MRE), might mimic bowel inflammation in the coronal view. This study investigated the prevalence of AP flattening and the factors associated with its development.

MATERIALS AND METHODS

A total of 364 surgery-naïve patients with Crohn's disease (CD) who had undergone MRE were retrospectively reviewed. AP flattening was defined as a luminal collapse in the anteroposterior direction, with a bowel width in the axial plane < 1/4 of the normal diameter without reduction of bowel width in coronal images. The prevalence of AP flattening of the TI and SC on MRE in patients with bowel segments lying across the psoas muscle was determined. We further compared the rate of AP flattening between MRE and computed tomography enterography (CTE) in a subcohort of patients with prior CTE. The factors associated with AP flattening were analyzed using multivariable logistic regression in a subcohort of patients with endoscopic findings of TI.

RESULTS

Three hundred and twenty-two and 363 patients, respectively, had TI and SC lying across the psoas muscle. The prevalence of AP flattening on MRE was 7.5% (24/322) in TI and 5.2% (19/363) in SC. The prevalences were significantly higher on MRE than on CTE in both the TI (7.3% [12/164] vs. 0.6% [1/164]; p = 0.003) and SC (5.8% [11/190] vs. 1.6% [3/190]; p = 0.039). AP flattening of the TI was independently and strongly associated with the absence of CD inflammation on endoscopy, with an adjusted odds ratio of 0.066 (p = 0.003) for the presence versus the absence (reference) of inflammation.

CONCLUSION

AP flattening of the TI or SC lying across the psoas muscle was uncommon and predominantly observed on MRE of the bowel without CD inflammation.

Radiation protection perspective to recurrent medical imaging: what is known and what more is needed?

This review summarises the current knowledge about recurrent radiological imaging and associated cumulative doses to patients. The recent conservative estimates are for around 0.9 million patients globally who cumulate radiation doses above 100 mSv, where evidence exists for cancer risk elevation. Around one in five is estimated to be under the age of 50. Recurrent imaging is used for managing various health conditions and chronic diseases such as malignancies, trauma, end-stage kidney disease, cardiovascular diseases, Crohn's disease, urolithiasis, cystic pulmonary disease. More studies are needed from different parts of the world to understand the magnitude and appropriateness. The analysis identified areas of future work to improve radiation protection of individuals who are submitted to frequent imaging. These include access to dose saving imaging technologies; improved imaging strategies and appropriateness process; specific optimisation tailored to the clinical condition and patient habitus; wider utilisation of the automatic exposure monitoring systems with an integrated option for individual exposure tracking in standardised patient-specific risk metrics; improved training and communication. The integration of the clinical and exposure history data will support improved knowledge about radiation risks from low doses and individual radiosensitivity. The radiation protection framework will need to respond to the challenge of recurrent imaging and high individual doses. The radiation protection perspective complements the clinical perspective, and the risk to benefit analysis must account holistically for all incidental and long-term benefits and risks for patients, their clinical history and specific needs. This is a step toward the patient-centric health care.

Radiation risk issues in recurrent imaging

Millions of patients benefit from medical imaging every single day. However, we have entered an unprecedented era in imaging practices wherein 1 out of 125 patients can be exposed to effective dose >50 mSv from a single CT exam and 3 out of 10,000 patients undergoing CT exams could potentially receive cumulative effective doses > 100 mSv in a single day. Recurrent imaging with CT, fluoroscopically guided interventions, and hybrid imaging modalities such as positron emission tomography/computed tomography (PET/CT) is more prevalent today than ever before. Presently, we do not know the cumulative doses that patients may be receiving across all imaging modalities combined. Furthermore, patients with diseases with longer life expectancies are being exposed to high doses of radiation enabling radiation effects to manifest over a longer time period. The emphasis in the past on improving justification of imaging and optimization of technique and practice has proved useful. While that must continue, the current situation requires imaging device manufacturers to urgently develop imaging technologies that are safer for patients as high doses have been observed in patients where imaging has been justified through clinical decision-support and optimized by keeping doses below the national benchmark doses. There is a need to have a critical look at the fundamental principles of radiation protection as cumulative doses are likely to increase in the coming years.

Clinically relevant thyroid disorders and inflammatory bowel disease are inversely related: a retrospective case-control study

OBJECTIVES

The risk of thyroid disorders (TDs) in inflammatory bowel disease (IBD) is still controversial. The aim of this retrospective, single-center, case-control study was to explore the association between clinically relevant functional TDs and IBD.

METHODS

Consecutive individuals for a total of 313 IBD patients [90 Crohn's disease (CD); 223 ulcerative colitis (UC)], and 833 individuals undergoing colonoscopy for screening without IBD were collected. In the study, subject's information on thyroid status were retrieved. Thyroid disorders were classified, according to the functional status, as hypothyroidism or hyperthyroidism. Patients with TDs (cases) were compared with 941 without (controls) according to IBD exposure. Unadjusted and adjusted odds ratios (ORs) and their 95% confidence interval (CI) were calculated.

RESULTS

Clinically relevant TDs were detected in 205 (17,9%) patients and the prevalence was significantly lower in IBD patients compared with subjects without (8.3% vs 12.9%; p = 0.029). After adjusting for potential confounders, a higher TDs risk was confirmed in female (OR 2.72; 95%CI 1.88‒3.92) and older subjects (OR 1.01; 95%CI 1.00‒1.03), and a lower risk in IBD (OR 0.51; 95%CI 0.34‒0.76), especially for hypothyroidism (OR 0.33; 95%CI 0.17‒0.66) in UC. Among four thyroid cancers, only one was detected in IBD patients.

CONCLUSIONS

Overall, in our study, the risk of TDs was lower in IBD patients. To assess routinely hormones and/or thyroid gland imaging in the absence of clinical signs or symptoms seems unnecessary in IBD patients, at least in our geographic area.

Higher patient doses through X-ray imaging procedures

Medical imaging using X-rays has been one of the most popular imaging modalities ever since the discovery of X-rays 125 years ago. With unquestionable benefits, concerns about radiation risks have frequently been raised. Computed tomography (CT) and fluoroscopic guided interventional procedures have the potential to impart higher radiation exposure to patients than radiographic examinations. Despite technological advances, there have been instances of increased doses per procedure mainly because of better diagnostic information in images. However, cumulative dose from multiple procedures is creating new concerns as effective doses >100 mSv are not uncommon. There is a need for action at all levels. Manufacturers must produce equipment that can provide a quality diagnostic image at substantially lesser dose and better implementation of optimization strategies by users. There is an urgent need for the industry to develop CT scanners with sub-mSv radiation dose, a goal that has been lingering. It appears that a new monochromatic X-ray source will lead to replacement of X-ray tubes all over the world in coming years and will lead to a drastic reduction in radiation doses. This innovation will impact all X-ray imaging and will help dose reduction. For interventional procedures, the likely employment of robotic systems in practice may drastically reduce radiation exposures to operators- but patient exposure will still remain an issue. Training needs always need to be emphasized and practiced.

Multinational data on cumulative radiation exposure of patients from recurrent radiological procedures: call for action

OBJECTIVES

To have a global picture of the recurrent use of CT imaging to a level where cumulative effective dose (CED) to individual patients may be exceeding 100 mSv at which organ doses typically are in a range at which radiation effects are of concern METHODS: The IAEA convened a meeting in 2019 with participants from 26 countries, representatives of various organizations, and experts in radiology, medical physics, radiation biology, and epidemiology. Participants were asked to collect data prior to the meeting on cumulative radiation doses to assess the magnitude of patients above a defined level of CED.

RESULTS

It was observed that the number of patients with CED ≥ 100 mSv is much larger than previously known or anticipated. Studies were presented in the meeting with data from about 3.2 million patients who underwent imaging procedures over periods of between 1 and 5 years in different hospitals. It is probable that an additional 0.9 million patients reach the CED ≥ 100 mSv every year globally.

CONCLUSIONS

There is a need for urgent actions by all stakeholders to address the issue of high cumulative radiation doses to patients. The actions include development of appropriateness criteria/referral guidelines by professional societies for patients who require recurrent imaging studies, development of CT machines with lower radiation dose than today by manufacturers, and development of policies by risk management organizations to enhance patient radiation safety. Alert values for cumulative radiation exposures of patients should be set up and introduced in dose monitoring systems.

KEY POINTS

• Recurrent radiological imaging procedures leading to high radiation dose to patients are more common than ever before. • Tracking of radiation exposure of individual patients provides useful information on cumulative radiation dose. • There is a need for urgent actions by all stakeholders to address the issue of high cumulative radiation doses to patients.

Comparison of the use of wireless capsule endoscopy with magnetic resonance enterography in children with inflammatory bowel disease

BACKGROUND

Magnetic resonance enterography (MRE) and wireless capsule endoscopy (WCE) are equally accepted modalities for noninvasive screening of small bowel involvement (SBI) in children with Crohn’s disease (CD) and indeterminate colitis (IC) albeit there is a paucity of data comparing the two and thereby guiding the clinician in selecting the ideal diagnostic approach. Therefore, the goal of this study is to provide additional evidence for capsule endoscopy role in the evaluation of established Crohn’s disease exacerbation compared to MRE in relation to Pediatric Crohn's Disease Activity Index (PCDAI), and histological indices.

AIM

To prospectively compare the findings of MRE and WCE and their agreement with PCDAI or histology in children with CD or IC.

METHODS

Consecutive patients diagnosed with CD and IC were screened for inclusion. After informed consent, patient’s demographic and clinical data was abstracted. The current pediatric disease activity index (PCDAI) and endoscopic findings were included. Patients underwent MRE and WCE including preprocedural patency capsule within a maximum of 7 d of each other. Pathological presence of active small bowel disease in ileal and duodenal biopsies were collected if the endoscopy was performed within 2 mo of the WCE study. Patients who failed to pass the PC were excluded from the study. WCE was read by two different experienced gastroenterologists (Attard TM and Colombo JM) blinded to each other's findings and to the findings on MRE (Mardis NJ). Agreement between WCE reviewers, WCE and MRE findings and concordance between positive PCDAI and SBI based on MRE compared with WCE was computed.

RESULTS

Forty-five patients were included in the study, 18 withdrew and 27 (20 males and 20 CD), mean age (standard deviation) 13.46 (2.4) years, completed the study protocol. There were no instances of capsule retention. Concordance between gastroenterologist reviewers was excellent for the diagnosis of small intestinal CD with good correlation between the two Lewis scores (r = 0.875, P < 0.001). Concordance between WCE and MRE was poor (69%). In CD patients, when both MRE and WCE were compared using PCDAI > 10 as the standard reference reflecting active small intestinal CD, the sensitivity of MRE and WCE were 100% and 83% respectively and the specificity of MRE and WCE were 57.14% and 78.6%, respectively. If the histology in ileum or/and duodenum was used as the reference for active small bowel involvement, WCE had a higher specificity as compared to MRE (83.3% vs 50%). In patients with Crohn’s disease, those with a positive PCDAI (> 10) were more likely to have a positive WCE as compared to those with a negative PCDAI (83% vs 21%; P = 0.018).

CONCLUSION

We suggest that MRE and WCE have a complementary role in the assessment of SBI in CD. WCE detected SBI with a much higher specificity while MRE had a higher sensitivity.

Reduced Imaging Radiation Exposure and Costs Associated with Anti-Tumor Necrosis Factor Therapy in Crohn's Disease

BACKGROUND

Radiation exposure from diagnostic imaging may increase cancer risk of Crohn's disease (CD) patients, who are already at increased risk of certain cancers.

AIM

To compare imaging radiation exposure and associated costs in CD patients during the year pre- and post-initiation of anti-tumor necrosis factor (anti-TNF) agents or corticosteroids.

METHODS

Adults were identified from a large US claims database between 1/1/2005 and 12/31/2009 with ≥ 1 abdominal imaging scan and 12 months of enrollment before and after initiating therapy with anti-TNF or corticosteroids. Imaging utilization, radiation exposure, and healthcare costs pre- and post-initiation were examined.

RESULTS

Anti-TNF-treated patients had significantly fewer imaging examinations the year prior to initiation than corticosteroid-treated patients. Cumulative radiation doses before initiation were significantly higher for corticosteroid patients compared to anti-TNF patients (22.3 vs. 17.7 millisieverts, P = 0.0083). After therapy initiation, anti-TNF-treated patients had significantly fewer imaging examinations (2.9 vs. 5.2, P < 0.0001) and less radiation exposure (7.4 vs. 15.4 millisieverts, P <0.0001) than corticosteroid-treated patients in the follow-up period. Reductions in imaging costs adjusted for 1000 patient-years after initiation of therapy were - $275,090 and - $121,960 (P = 0.0359) for anti-TNF versus corticosteroid patients, respectively.

CONCLUSIONS

This analysis demonstrated that patients treated with anti-TNF agents have fewer imaging examinations, less radiation exposure, and lower healthcare costs associated with imaging than patients treated with corticosteroids. These benefits do not account for additional long-term benefits that may be gained from reduced radiation exposure.

Low-Dose Computed Tomography for the Optimization of Radiation Dose Exposure in Patients with Crohn's Disease

Magnetic resonance imaging (MRI) is the mainstay method for the radiological imaging of the small bowel in patients with inflammatory bowel disease without the use of ionizing radiation. There are circumstances where imaging using ionizing radiation is required, particularly in the acute setting. This usually takes the form of computed tomography (CT). There has been a significant increase in the utilization of computed tomography (CT) for patients with Crohn's disease as patients are frequently diagnosed at a relatively young age and require repeated imaging. Between seven and eleven percent of patients with IBD are exposed to high cumulative effective radiation doses (CEDs) (>35–75 mSv), mostly patients with Crohn's disease (Newnham E 2007, Levi Z 2009, Hou JK 2014, Estay C 2015). This is primarily due to the more widespread and repeated use of CT, which accounts for 77% of radiation dose exposure amongst patients with Crohn's disease (Desmond et al., 2008). Reports of the projected cancer risks from the increasing CT use (Berrington et al., 2007) have led to increased patient awareness regarding the potential health risks from ionizing radiation (Coakley et al., 2011). Our responsibilities as physicians caring for these patients include education regarding radiation risk and, when an investigation that utilizes ionizing radiation is required, to keep radiation doses as low as reasonably achievable: the “ALARA” principle. Recent advances in CT technology have facilitated substantial radiation dose reductions in many clinical settings, and several studies have demonstrated significantly decreased radiation doses in Crohn's disease patients while maintaining diagnostic image quality. However, there is a balance to be struck between reducing radiation exposure and maintaining satisfactory image quality; if radiation dose is reduced excessively, the resulting CT images can be of poor quality and may be nondiagnostic. In this paper, we summarize the available evidence related to imaging of Crohn's disease, radiation exposure, and risk, and we report recent advances in low-dose CT technology that have particular relevance.

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.

Radiation exposure in patients with inflammatory bowel disease and irritable bowel syndrome in the years 2001-2011

OBJECTIVES

To compare cumulative ionizing radiation in patients with inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) for the years 2001-2011. To study how radiation exposure change over time in patients with newly diagnosed IBD and factors associated with radiation exposure.

MATERIAL AND METHODS

All radiological investigations performed between 1 January 2001 and 31 December 2011 were retrospectively recorded in patients with Crohn's disease (CD) (n = 103), ulcerative colitis (UC) (n = 304) and IBS (n = 149). Analyses were done with Mann-Whitney and Chi-Square test.

RESULTS

The median total cumulative radiation exposure in mSv for CD (20.0, inter quartile range (IQR) 34.8), UC (7.01, IQR 23.8), IBS (2.71, IQR 9.15) and the proportion of patients who had been exposed for more than 50 mSv during the study period (CD 19%, UC 11%, IBS 3%) were significantly higher in the patients with CD compared to patients with UC (p < .001) and IBS (p < .001), respectively. In turn, patients with UC had significantly higher doses than patients with IBS (p = .005). Risk factors for radiation exposure were female gender (CD), early onset (UC), ileocolonic location (CD), previous surgery (CD and UC), depression (IBS) and widespread pain (IBS). In newly diagnosed CD, there was a significant decline in median cumulative radiation dose in mSv (17.2 vs. 12.0; p = .048) during the study period.

CONCLUSIONS

Patients with CD are at greatest risk for high cumulative radiation exposure, but there is a decline in exposure during the late 2000s. Non-colectomized patients with UC and patients with IBS have a relatively low risk of cumulative radiation exposure.

Crohn's Disease Is Associated with the Risk for Thyroid Cancer

BACKGROUND

It is known that inflammatory bowel disease (IBD) is associated with a high risk for some of extraintestinal cancers. The aim of this study was to identify whether IBD is associated with thyroid cancer using a large national database.

METHODS

We performed a case-control study using the 2012 National Inpatient Sample (NIS) database. The study group included all patients with Crohn's disease (CD) (ICD-9 Code: 555) and ulcerative colitis (UC) (ICD-9 Code: 556), and the control group included all patients with diverticulitis (ICD-9 Code: 562.11, 562.13). Both univariable and multivariable analyses were performed to assess the risk factors associated with thyroid cancer.

RESULTS

We analyzed more than 28 million hospitalizations in 2012, with 289,935 being IBD-related admissions and 315,145 being diverticulitis-related admissions. Subjects who had IBD were found to be significantly more likely to have thyroid cancer than those with diverticulitis (odds ratio = 1.97 [1.5-2.6], P = 0.033). There was no difference between men and women in the prevalence of thyroid cancer in IBD (P = 0.6). There was no difference between CD and UC (P = 0.14) and between UC and diverticulitis (P = 0.93). In multivariate analysis, CD was found to be associated with thyroid cancer (odds ratio = 2.3 [1.06-5.1], P = 0.034). Age was shown to be a protective factor in the presence of thyroid cancer (P < 0.005), and a higher Charlson comorbidity index was associated with the presence of thyroid cancer (odds ratio, 1.5 [1.3-1.7]; P < 0.001).

CONCLUSIONS

Our study showed that CD, not UC, is associated with a higher risk for thyroid cancer. It is recommended that patients with CD may need a close monitoring of thyroid diseases.

Pure Iterative Reconstruction Improves Image Quality in Computed Tomography of the Abdomen and Pelvis Acquired at Substantially Reduced Radiation Doses in Patients With Active Crohn Disease

We assessed diagnostic accuracy and image quality of modified protocol (MP) computed tomography (CT) of the abdomen and pelvis reconstructed using pure iterative reconstruction (IR) in patients with Crohn disease (CD).

METHODS

Thirty-four consecutive patients with CD were referred with suspected extramural complications. Two contemporaneous CT datasets were acquired in all patients: standard protocol (SP) and MP. The MP and SP protocols were designed to impart radiation exposures of 10% to 20% and 80% to 90% of routine abdominopelvic CT, respectively. The MP images were reconstructed with model-based IR (MBIR) and adaptive statistical IR (ASIR).

RESULTS

The MP-CT and SP-CT dose length product were 88 (58) mGy.cm (1.27 [0.87] mSv) and 303 [204] mGy.cm (4.8 [2.99] mSv), respectively (P < 0.001). Median diagnostic acceptability, spatial resolution, and contrast resolution were significantly higher and subjective noise scores were significantly lower on SP-ASIR 40 compared with all MP datasets. There was perfect clinical agreement between MP-MBIR and SP-ASIR 40 images for detection of extramural complications.

CONCLUSIONS

Modified protocol CT using pure IR is feasible for assessment of active CD.

ACR Appropriateness Criteria Crohn Disease

Crohn disease is a chronic inflammatory disorder involving the gastrointestinal tract, characterized by episodic flares and times of remission. Underlying structural damage occurs progressively, with recurrent bouts of inflammation. The diagnosis and management of this disease process is dependent on several clinical, laboratory, imaging, endoscopic, and histologic factors. In recent years, with the maturation of CT enterography, and MR enterography, imaging has played an increasingly important role in relation to Crohn Disease. In addition to these specialized examination modalities, ultrasound and routine CT have potential uses. Fluoroscopy, radiography, and nuclear medicine may be less beneficial depending on the clinical scenario. The imaging modality best suited to evaluating this disease may change, depending on the target population, severity of presentation, and specific clinical situation. This document presents seven clinical scenarios (variants) in both the adult and pediatric populations and rates the appropriateness of the available imaging options. They are summarized in a consolidated table, and the underlying rationale and supporting literature are presented in the accompanying narrative. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Risk factors for radiation exposure in newly diagnosed IBD patients

PURPOSE

Patients with inflammatory bowel disease (IBD) may be exposed to high doses of diagnostic radiation. The purpose of this study is to identify subsets of this population at risk for significant radiation exposure.

METHODS

This HIPAA compliant, IRB approved study consists of 336 patients (237 adult and 99 pediatric) within the Ocean State Crohn's & Colitis Area Registry (OSCCAR). All were newly diagnosed with IBD and prospectively enrolled between 1/2008 and 12/2012. Comprehensive chart review was performed.

RESULTS

207 (61.6%) patients were diagnosed with Crohn's disease (CD), 120 (35.7%) with ulcerative colitis (UC), and 9 (2.7%) with inflammatory bowel disease, type unspecified (IBDU). 192 (57.1%) patients were exposed to GI-specific radiation. Average GI-specific radiation dose for adult IBD patients was 14.1 mSV and was significantly greater among adult CD than adult UC patients (p = 0.01). Pediatric patients underwent fewer CT scans (p < 0.0001). Risk factors for increased radiation exposure include: GI surgery (p = 0.003), biologic therapy (p = 0.01), pain-predominant symptoms (as compared to diarrhea-predominant symptoms; p < 0.05), and isolated ileal disease (p = 0.02). Patients with stricturing or penetrating disease received higher radiation doses than patients with non-stricturing, non-penetrating disease (p < 0.0001).

CONCLUSIONS

A variety of risk factors are associated with increased exposure to ionizing radiation after diagnosis of IBD. Knowledge of these risk factors can help physicians prospectively identify patients at risk for elevated radiation exposure and consider low-dose or radiation-free imaging.

Considerations in Imaging Among Emergency Department Patients With Inflammatory Bowel Disease

Patients with inflammatory bowel disease who experience abdominal pain and gastrointestinal symptoms often seek care in the emergency department (ED). These patients commonly undergo abdominopelvic computed tomography (CT) as part of their evaluation, and the rate of imaging appears to be increasing without a corresponding increase in identification of clinically actionable findings or effect on disposition. Studies demonstrate that the yield of CT tends to be fairly high. Yet, because inflammatory bowel disease is often diagnosed at an early age, these patients are repeatedly imaged during their lifetime, a subset of whom accumulate high levels of ionizing radiation exposure, increasing their risk of cancer. This compounds an already increased risk of cancer in these patients because of inflammatory bowel disease alone. Lack of intimate knowledge of a patient's disease phenotype and disease progression contributes to uncertainty in distinguishing between an inflammatory exacerbation; a complication such as obstruction, abscess, perforation, fistula, or stricture; and a noninflammatory-bowel-disease-related condition. This uncertainty can lead to overuse of imaging with CT. Limited availability of and lack of awareness of alternate imaging modalities and strategies may prevent providers from pursuing strategies that avoid ionizing radiation. In this article, we review options for imaging inflammatory bowel disease patients in the ED and attempts undertaken to risk stratify these patients, and we discuss ways in which details of a patient's disease might guide imaging decisionmaking.

Ionizing radiation exposure is still increasing in Crohn's disease: Who should be blamed?

BACKGROUND AND AIM

Crohn's disease (CD) patients undergo many radiological studies employing ionizing radiation for diagnosis and management purposes. Our aim was to assess the total radiation exposure of our patients over the years, to estimate the risk factors for exposure to high doses, and to correlate radiation exposure to immunosuppression.

METHODS

The cumulative effective dose of radiation (CEDR) was calculated multiplying the number of imaging studies by the effective dose of each examination.

RESULTS

A total of 451 patients with CD (226 female) were followed during 11.0 years (interquartile range [IQR]: 6.0-16.0), with 52.1% of the patients being classified with penetrating (B3) and 38.6% being steroid-dependent. About 16% were exposed to high-radiation dose levels (CEDR >50 mSv) and 4% were exposed to CEDR >100 mSv. The mean CEDR between age 26 and 35 years was 12.539 mSv and a significant dose of radiation (over 50 mSv) was achieved at a median age of 40 (IQR: 29.0-47.0). Abdominal-pelvic computed tomography scan was the examination that contributed the most for CEDR. Patients with B3 phenotype, previous surgery, azathioprine, and anti-tumor necrosis factor (TNF)-α therapy were exposed earlier on the course of the disease to CEDR >50 mSv (p < 0.001). The value of CEDR in the patients under immunosuppression mainly increased in the first year of immunosuppression.

CONCLUSION

Penetrating phenotype, abdominal surgery, steroid resistance or steroid dependence, and treatment with anti-TNF-α and azathioprine were predictive factors for high CEDR. It was also demonstrated that immunosuppression and anti-TNF-α treatment were followed by a sustained increment of radiation exposure and that a significant dose of radiation was achieved <40 years of age.

Role of imaging in the evaluation of inflammatory bowel disease: How much is too much?

Inflammatory bowel disease (IBD) is a lifelong condition with waxing and waning disease course that requires reassessment of disease status as well as screening for complications throughout a patient’s lifetime. Laboratory testing, endoscopic assessment, and fecal biomarkers are often used in the initial diagnosis and ongoing monitoring of a patient with IBD. Imaging plays an integral role in the diagnosis and evaluation of IBD. Different imaging modalities can be used over the course of a patient’s lifetime, from the initial screening and diagnosis of IBD, to determining the extent of intestinal involvement, monitoring for disease activity, and evaluating for complications of uncontrolled IBD. The various imaging modalities available to the provider each have a unique set of risks and benefits when considering cost, radiation exposure, need for anesthesia, and image quality. In this article we review the imaging techniques available for the evaluation of IBD including fluoroscopic small bowel follow-through, computed tomography enterography, magnetic resonance enterography, and transabdominal ultrasound with particular focus on the judicious use of imaging and the risks and benefits of each option. We also review the risks of ionizing radiation, strategies to reduce exposure to ionizing radiation, and current imaging guidelines among pediatric and adult patient with IBD.

Model-Based Iterative Reconstruction in CT Enterography

OBJECTIVE

The purpose of this study was to analyze the performance of pure model-based iterative reconstruction (MBIR) in low-dose CT enterography.

SUBJECTS AND METHODS

Forty-four patients with Crohn disease referred for CT enterography were included. Low-dose modified-protocol and conventional-protocol CT datasets were contemporaneously acquired. Conventional-protocol image formation was performed with 40% adaptive statistical iterative reconstruction (ASIR). Modified-protocol data were reconstructed with 100% MBIR and 40% ASIR. Image quality was assessed subjectively and objectively at six levels. Independent clinical interpretations by two fully blinded radiologists were compared with reference standard consensus reviews by two nonblinded readers who had access to clinical information, previous imaging studies, and medical records.

RESULTS

A 74.7% average radiation dose reduction was seen: low-dose modified-protocol effective dose, 1.61 ± 1.18 mSv (size-specific-dose-estimate, 2.47 ± 1.21 mGy); conventional-protocol effective dose, 6.05 ± 2.84 mSv (size-specific-dose-estimate, 9.25 ± 2.9 mGy). Image quality assessment yielded 9372 data points. Objective noise on modified-protocol MBIR images was superior (p < 0.05) to that with the conventional protocol at three of six levels and comparable at the other three levels. Modified-protocol images were superior to conventional-protocol ASIR images (p < 0.05 in all cases) for subjective noise, spatial resolution, contrast resolution, streak artifact, and diagnostic acceptability on coronal reconstructions. Axial diagnostic acceptability was superior for conventional-protocol ASIR (p = 0.76). For both readers, modified-protocol MBIR clinical readings agreed more closely with reference standard readings than did conventional-protocol ASIR readings with regard to bowel wall disease assessment (κ = 0.589 and 0.700 vs 0.583 and 0.564). Overall Crohn disease activity grade (κ = 0.549 and 0.441 vs 0.315 and 0.596) and detection of acute complications (κ = 1.0 and 0.689 vs 0.896 and 0.896) were comparable when evaluated on conventional-protocol ASIR and modified-protocol MBIR images.

CONCLUSION

Low-dose CT enterography with MBIR yields images that are comparable to or superior to conventional images.

Use of Imaging Techniques in Inflammatory Bowel Diseases That Minimize Radiation Exposure

The use of imaging in the management of inflammatory bowel disease (IBD) has grown exponentially in the last few years. This has raised concerns about the risk of high cumulative level of radiation exposure from medical imaging in IBD patients during their lifetime, especially when the disease begins in pediatric age. Physicians caring for IBD children should be aware of the malignant potential of ionizing radiation and of the availability of alternative radiation-free techniques such as magnetic resonance imaging (MRI) and ultrasonography (US), in order to use them whenever possible. This review will focus on the value of US and MRI in pediatric IBD.

Predictors of Urgent Findings on Abdominopelvic CT in Patients with Crohn's Disease Presenting to the Emergency Department

BACKGROUND

Patients with Crohn's disease (CD) are frequently exposed to diagnostic radiation, mainly as a result of abdominopelvic computed tomography (APCT) examinations. However, there are limited data on the impact of APCT on clinical management in this population.

AIM

To investigate clinical predictors of urgent findings on APCT in patients with CD who presented to the emergency department (ED).

METHODS

A retrospective study was performed among patients with CD presenting to 11 EDs with a gastrointestinal complaint. The primary outcome, OPAN (obstruction, perforation, abscess, or non-CD-related urgent findings), included new or worsening CD-related urgent findings or non-CD-related urgent findings that required urgent or emergency treatment. Variables with P < 0.1 in univariate analyses were included in a multivariable logistic regression model.

RESULTS

Of the 266 APCTs performed, 103 (38.7 %) had OPAN and 113 (42.5 %) required changes in treatment plan. Stricturing or penetrating disease (odds ratio [OR] 2.72, 95 % confidence interval [CI] 1.21-6.13), heart rate >100 beats/min (OR 2.33, 95 % CI 1.10-4.93), leukocyte count >10,000/mm(3) (OR 4.38, 95 % CI 2.10-9.13), and CRP >2.5 mg/dL (OR 3.11, 95 % CI 1.23-7.86) were identified as the independent predictors of OPAN, whereas biologic agent use (OR 0.37; 95 % CI 0.15-0.90) was identified as the negative predictor in patients with CD.

CONCLUSIONS

Only 39 % of the APCTs performed in the ED among patients with CD showed urgent findings. Stricturing or penetrating disease, tachycardia, leukocytosis, and high CRP level were predictors of urgent CT findings, while biologic agent use was a negative predictor. To reduce unnecessary radiation exposure, the selection process for CD patients referred for APCT must be improved.

Ionizing radiation exposure in patients with inflammatory bowel disease: are we overexposing our patients?

OBJECTIVE

Imaging techniques are accurate and reliable in diagnosing inflammatory bowel disease (IBD). However, the main disadvantage of computed tomography (CT) compared with magnetic resonance imaging (MRI) is radiation exposure and the potential risk of cancer, especially since IBD patients are at increased risk of malignancies. This study aims to quantify and characterize effective radiation exposure of IBD patients.

METHODS

A cohort of IBD patients were retrospectively enrolled in the Clínica las Condes IBD registry between 2011 and 2013. High cumulative radiation exposure (CED) was defined as ≥-50 mSv.

RESULTS

A total of 325 IBD patients were enrolled in our registry, including 243 (74.8%) with UC and 82 (25.2%) with CD. The patients with CD were more commonly to reach a high CED seen compared with those with UC (19.5% vs 2.5%). Higher exposure to radiation was associated with longer duration of disease, ileal involvement, stricturing behavior, treatments with steroids and biological agents and CD-related hospitalization or surgery. Abdominopelvic CT and enteroclysis CT accounted for 93.6% of total CED.

CONCLUSIONS

A high percentage of IBD patients are exposed to high CED. Radiation-free cross-sectional examinations, such as MRI, should be used, especially in young patients, those who have undergone prior surgery and those with severe IBD.

An overview of magnetic resonance enterography for Crohn's disease

Magnetic resonance enterography (MRE) is a relatively new imaging modality that has shown promise for diagnosing, staging, and monitoring Crohn's disease (CD) and its complications while avoiding exposure to ionizing radiation. In addition to clinical implications, MRE has the potential to be used as an objective measure of disease activity for clinical trials. We provide the rationale for MRE, indications for its use, and an overview of the typical procedure and common findings for institutions who want to begin or refine the use of MRE for CD.

Radiation exposure from diagnostic imaging studies among patients with inflammatory bowel disease in a safety-net health-care system

BACKGROUND/AIMS

Radiographic imaging studies are important in the management of patients with inflammatory bowel disease (IBD), but are associated with radiation exposure. IBD patients in a safety-net health-care system may be at risk of high exposure to radiation. Our purpose was to identify associations of high-dose radiation exposure among an ethnically diverse cohort of IBD patients in a safety-net health-care system.

METHODS

A study was performed on patients with IBD receiving care from the Harris County Hospital District. Radiation exposure was calculated using total number of imaging studies performed between from 2000 and 2010 and estimates of radiation dose per study. Associations of high-dose radiation exposure, defined as a cumulative effective dose (CED) >50 mSv, were identified by using univariate and multivariate logistic regression.

RESULTS

The study cohort of 278 patients with IBD was ethnically diverse, with 30 % Caucasian, 44 % African-American, and 26 % Hispanic. The median CED was 10.40 mSv (SD 20.02). Annualized radiation doses were 3.45 mSv/year among patients with Crohn's disease (CD) and 1.27 mSv/year among patients with ulcerative colitis, p < 0.02. Approximately 13 % of IBD patients received a CED >50 mSv. There were no differences in radiation exposure based on age, gender, or race/ethnicity.

CONCLUSIONS

A small proportion of IBD patients in a safety-net health-care system received high doses of diagnostic radiation exposure. Use of diagnostic imaging studies that limit radiation exposure should be encouraged.

Drug therapies and the risk of malignancy in Crohn's disease: results from the TREAT™ Registry

OBJECTIVES

We assessed potential associations between malignancy and antitumor necrosis factor therapy in patients with Crohn's disease (CD), as this relationship is currently poorly defined.

METHODS

Utilizing data from the Crohn's Therapy, Resource, Evaluation, and Assessment Tool (TREAT™) Registry, a prospective cohort study examining long-term outcomes of CD treatments in community and academic settings, influences of baseline patient/disease characteristics and medications were assessed by survival analysis and multivariate models. Standardized incidence ratios and exact 95 % confidence intervals were determined as the ratio of events observed (TREAT) vs. expected (general population of USA).

RESULTS

As of 23 February 2010, 6,273 CD patients (infliximab during registry=3,420 (during or within 1 year before registry=3,764); other-treatments-only: 2,509), were enrolled and, on average, had been followed for 5.2/7.6 years, respectively, for all/currently active patients. Crude cancer incidences were similar between infliximab- and other-treatments-only-exposed patients. Multivariate Cox regression analysis demonstrated that baseline age (hazard ratio (HR)=1.59/10 years; P<0.001), disease duration (HR=1.64/10 years; P=0.012), and smoking (HR=1.38; P=0.045) but neither immunosuppressive therapy alone (HR=1.43; P=0.11), infliximab therapy alone (HR=0.59; P=0.16), nor their combination (HR=1.22, P=0.34) were independently associated with the risk of malignancy. When compared with the general population, no significant increase in incidence was observed in any malignancy category. In an exposure-based analysis, use of immunosuppressants alone (odds ratio=4.19) or in combination with infliximab (3.33) seemed to be associated with a numerically, but not significantly, greater risk of malignancy than did treatment with infliximab alone (1.96) relative to treatment with neither.

CONCLUSIONS

In the TREAT Registry, age, disease duration, and smoking were independently associated with increased risk of malignancy. Although results for immunosuppressant use were equivocal, no significant association between malignancy and infliximab was observed.

Radiation exposure from abdominal imaging studies in patients with intestinal Behçet disease

Background/Aims

Recently, several studies have revealed that diagnostic imaging can result in exposure to harmful levels of ionizing radiation in inflammatory bowel disease patients. However, the extent of radiation exposure in intestinal Behcet disease (BD) patients has not been documented. The aim of this study was to estimate the radiation exposure from abdominal imaging studies in intestinal BD patients.

Methods

Patients with a diagnosis of intestinal BD established between January 1990 and March 2012 were investigated at a single tertiary academic medical center. The cumulative effective dose (CED) was calculated retrospectively from standard tables and by counting the number of abdominal imaging studies performed. High exposure was defined as CED >50 mSv.

Results

In total, 270 patients were included in the study. The mean CED was 41.3 mSv, and 28.1% of patients were exposed to high levels of radiation. Computed tomography (CT) accounted for 81.7% of the total effective dose. In multivariate analyses, predictors of high radiation exposure were azathioprine/6-mercaptopurine use, surgery, and hospitalization.

Conclusions

Approximately a quarter of intestinal BD patients were exposed to harmful levels of diagnostic radiation, mainly from CT examination. Clinicians should reduce the number of unnecessary CT examinations and consider low-dose CT profiles or alternative modalities such as magnetic resonance enterography.

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.

Temporal trends in imaging and associated radiation exposure in inflammatory bowel disease

OBJECTIVES

Increasing use of diagnostic imaging in inflammatory bowel disease (IBD) has led to concerns about the malignant potential of ionising radiation in a cohort that have an increased lifetime risk of gastrointestinal malignancy. The aim was to quantify radiation exposure in IBD patients referred from primary care, determine predictors of high exposure and evaluate temporal trends in diagnostic imaging over a 20-year period.

METHODS

This was a retrospective cohort study whereby IBD patients were recruited from the outpatient clinic and evaluated retrospectively. The total cumulative effective dose (CED) received from tests was calculated for each subject. Cox regression was performed to assess factors associated with potentially harmful levels of ionising radiation defined as total CED > 50 milli-sieverts (mSv; equivalent to five CT abdomen scans).

RESULTS

The cohort included 415 patients. Median total CED was 7.2 mSv (IQR: 3.0-22.7) in Crohn's disease and 2.8 mSv (IQR: 0.8-8.9) in ulcerative colitis patients, respectively. A total of 32 patients (8%) received a CED > 50 mSv. A history of IBD-related surgery was associated with high exposure (HR 7.7). During the study period, usage of abdominal CT increased by 310%.

CONCLUSION

Approximately 1 in 13 patients in the study cohort were exposed to potentially harmful levels of ionising radiation. Strategies to minimise exposure to diagnostic medical radiation in IBD patients are required.

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.

Quantifying exposure to diagnostic radiation and factors associated with exposure to high levels of radiation in Korean patients with inflammatory bowel disease

BACKGROUND

Several recent studies have revealed that diagnostic imaging can result in exposure to potentially harmful levels of ionizing radiation in patients with inflammatory bowel disease (IBD). However, these studies have been conducted exclusively in Western countries, and no data are available in Asian populations. The aim of this study was to estimate the diagnostic radiation exposure in Korean patients with IBD and to determine the factors associated with high radiation exposure.

METHODS

Patients with an established diagnosis of IBD between July 1987 and January 2012 were investigated in 13 university hospitals in Korea. The cumulative effective dose (CED) was calculated retrospectively from standard tables.

RESULTS

A total of 777 patients with Crohn's disease (CD) and 1422 patients with ulcerative colitis (UC) were included in the study. The mean CED for CD and UC were 53.6 and 16.4 mSv, respectively (P < 0.001). CTof CD and UC accounted for 81.6% and 71.2% of total effective dose, respectively. Importantly, 34.7% of patients with CD and 8.4% of patients with UC were exposed to high levels of radiation (CED > 50 mSv) (P < 0.001). High radiation exposure was associated with long disease duration, ileocolonic disease, upper gastrointestinal tract involvement, surgical intervention, hospitalization, and the requirement for oral steroids in CD, and with surgical intervention, hospitalization, and the requirement for infliximab in UC.

CONCLUSIONS

A substantial proportion of patients with IBD, especially patients with CD, were exposed to significantly harmful amounts of diagnostic radiation, mainly as a result of CT examination. Given that IBD is a life-long illness, strategies to reduce radiation exposure from diagnostic imaging need to be considered.

Imaging techniques for assessment of inflammatory bowel disease: joint ECCO and ESGAR evidence-based consensus guidelines

The management of patients with IBD requires evaluation with objective tools, both at the time of diagnosis and throughout the course of the disease, to determine the location, extension, activity and severity of inflammatory lesions, as well as, the potential existence of complications. Whereas endoscopy is a well-established and uniformly performed diagnostic examination, the implementation of radiologic techniques for assessment of IBD is still heterogeneous; variations in technical aspects and the degrees of experience and preferences exist across countries in Europe. ECCO and ESGAR scientific societies jointly elaborated a consensus to establish standards for imaging in IBD using magnetic resonance imaging, computed tomography, ultrasonography, and including also other radiologic procedures such as conventional radiology or nuclear medicine examinations for different clinical situations that include general principles, upper GI tract, colon and rectum, perineum, liver and biliary tract, emergency situation, and the postoperative setting. The statements and general recommendations of this consensus are based on the highest level of evidence available, but significant gaps remain in certain areas such as the comparison of diagnostic accuracy between different techniques, the value for therapeutic monitoring, and the prognostic implications of particular findings.

Cumulative radiation dose from medical imaging in chronic adult patients

Chronic patients require ongoing care that results in repeated imaging and exposure to ionizing radiation for both diagnostic and therapeutic purposes. This is of concern due to the long-term effects of radiation exposure, namely the association between radiation and increased cancer risk. In this study, the scientific literature on cumulated dose of radiation accrued from medical imaging by 4 cohorts of chronic patients (cardiac disease, end-stage kidney disease, inflammatory bowel disease, and patients undergoing endovascular aortic repair) was systematically reviewed. We found that the cumulative effective dose is moderate in cardiac and inflammatory bowel disease patients, high in end-stage kidney disease patients, and very high in endovascular aortic repair patients. We concluded that radiation burden of medical imaging is high in selected cohorts of chronic patients. Efforts should be implemented to reduce this cumulative dose and its potential attendant risks.

Psychiatric co-morbidity is associated with increased risk of surgery in Crohn's disease

BACKGROUND

Psychiatric co-morbidity, in particular major depression and anxiety, is common in patients with Crohn's disease (CD) and ulcerative colitis (UC). Prior studies examining this may be confounded by the co-existence of functional bowel symptoms. Limited data exist examining an association between depression or anxiety and disease-specific endpoints such as bowel surgery.

AIMS

To examine the frequency of depression and anxiety (prior to surgery or hospitalisation) in a large multi-institution electronic medical record (EMR)-based cohort of CD and UC patients; to define the independent effect of psychiatric co-morbidity on risk of subsequent surgery or hospitalisation in CD and UC, and to identify the effects of depression and anxiety on healthcare utilisation in our cohort.

METHODS

Using a multi-institution cohort of patients with CD and UC, we identified those who also had co-existing psychiatric co-morbidity (major depressive disorder or generalised anxiety). After excluding those diagnosed with such co-morbidity for the first time following surgery, we used multivariate logistic regression to examine the independent effect of psychiatric co-morbidity on IBD-related surgery and hospitalisation. To account for confounding by disease severity, we adjusted for a propensity score estimating likelihood of psychiatric co-morbidity influenced by severity of disease in our models.

RESULTS

A total of 5405 CD and 5429 UC patients were included in this study; one-fifth had either major depressive disorder or generalised anxiety. In multivariate analysis, adjusting for potential confounders and the propensity score, presence of mood or anxiety co-morbidity was associated with a 28% increase in risk of surgery in CD (OR: 1.28, 95% CI: 1.03-1.57), but not UC (OR: 1.01, 95% CI: 0.80-1.28). Psychiatric co-morbidity was associated with increased healthcare utilisation.

CONCLUSIONS

Depressive disorder or generalised anxiety is associated with a modestly increased risk of surgery in patients with Crohn's disease. Interventions addressing this may improve patient outcomes.

Radiation exposure in patients with inflammatory bowel disease--primum non nocere?

BACKGROUND

Patients with Inflammatory Bowel disease (IBD) are frequently exposed to diagnostic medical radiation for the diagnosis and evaluation of their disease. Despite increasing awareness of the potentially serious downstream effects, few studies have quantified radiation exposure in IBD patients.

METHODS

We conducted a retrospective review of 280 consecutive patients attending IBD clinics at our hospital. All incidences of diagnostic medical radiation from initial diagnosis until 30 June 2010 inclusive were recorded. The radiation dose for each procedure was obtained from standardized tables and the effective dose for each procedure calculated by multiplying this value by the number of procedures during the study period. The sum of doses received was the cumulative effective dose.

RESULTS

The mean and median cumulative effective radiation doses were 10.17 mSv and 4.12 mSv respectively. Crohn's disease patients had significantly higher cumulative effective radiation exposure than UC patients (p < 0.001) with exposure exceeding 10 mSv in 58.3%, 25 mSv in 18.1% and 50 mSv in 6.3%, respectively. Smoking status, disease duration, and previous surgery were significant predictors for increased radiation exposure even after adjusting for other predictors. 47 small bowel magnetic resonance (MR) studies were undertaken as an alternative to ionising radiation in the last 3 years.

CONCLUSIONS

Patients with IBD, particularly those with Crohn's disease, are exposed to significant amounts of diagnostic medical radiation in their lifetime. Clinicians must remain vigilant to the risk of cumulative radiation when evaluating these patients and consider non-ionizing alternatives such as intestinal ultrasound and MR imaging where clinically appropriate.

Investigation of small bowel in pediatric Crohn's disease

Investigation of the small bowel has been traditionally a challenge for pediatric gastroenterologists due to its location, anatomical tortuosity, and invasiveness of the available techniques. Recently, there has been a remarkable improvement in imaging and endoscopic tools aimed at exploring successfully the small intestine in inflammatory bowel disease. The former are represented by ultrasonography (either alone or with administration of oral contrast agents) and by magnetic resonance: both have provided accurate methods to detect structural bowel changes, diminishing patient discomfort and precluding radiation hazard. The use of traditional radiologic techniques such as fluoroscopy have been markedly reduced due to radiation exposure and inability to depict transmural inflammation or extraluminal complications. Among the novel endoscopic tools, capsule endoscopy and balloon-assisted enteroscopy have tremendously opened new diagnostic and therapeutic perspectives, by allowing the direct visualization of small intestinal mucosa and, through enteroscopy, histological diagnosis as well as therapeutic interventions such as stricture dilation and bleeding treatment. These endoscopic techniques should always be preceded by imaging of the intestine in order to identify strictures. This review describes the most recent progress with the employment of novel imaging and endoscopic methodologies for investigating the small bowel in children with suspected or established Crohn's disease.

Selection of symptomatic patients with Crohn's disease for abdominopelvic computed tomography: role of serum C-reactive protein

BACKGROUND

Results of previous studies have shown that repeated abdominopelvic computed tomography (CT) examinations can lead to substantial cumulative diagnostic radiation exposure in patients with Crohn's disease (CD). Improved selection of patients referred for CT will reduce unnecessary radiation exposure. This study examines if serum C-reactive protein (CRP) concentration predicts which symptomatic patients with CD are likely to have significant disease activity or disease complications (such as abscess) detected on abdominopelvic CT.

METHODS

All abdominopelvic CTs performed on patients with CD at a tertiary referral centre during the period June 2003 to June 2008 were identified. CT findings were coded by a pair of independent blinded senior radiologists for (i) small bowel luminal disease, (ii) large bowel luminal disease, (iii) mesenteric inflammatory changes, (iv) penetrating disease (fistulas, abscess, or phlegmon), (v) acute disease complications (obstruction or perforation), and (vi) acute non-CD findings. Imaging findings were correlated with serum CRP checked within 14 days before imaging. The reference range for CRP was defined as 0-5 mg/L.

RESULTS

A total of 147 patients with symptomatic CD had a CRP assay performed within 14 days before undergoing abdominopelvic CT. The median time from CRP assay to imaging was 2 days (interquartile range, 0-6 days). Median CRP before imaging was 24 mg/L (interquartile range, 6-88 mg/L). CT was normal in 34 of 147 case (23.1%). Patients with normal CRP (n = 36) were significantly less likely to have penetrating disease (odds ratio [OR], 0.04 [95% confidence interval {CI}, 0.01-0.7]; P < .001) or large bowel luminal disease (OR, 0.3 [95% CI, 0.1-0.8]; P < .05). Normal CRP excluded penetrating disease with a sensitivity of 1.0 (95% CI, 0.87-1.0). CRP levels did not correlate with the presence of small bowel luminal disease (n = 82), mesenteric inflammatory changes (n = 68), or acute disease complications (n = 10).

CONCLUSION

Symptomatic patients with CD and normal serum CRP are unlikely to have evidence of abscess, fistulating disease, or large bowel luminal disease detected on abdominopelvic CT. However, abdominopelvic CT may demonstrate evidence of clinically significant non-penetrating CD or complications, including perforation and acute obstruction, regardless of serum CRP concentration.