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

Demonstrating the use of population level data to investigate trends in the rate, radiation dose and cost of Computed Tomography across clinical groups: Are there any areas of concern?

INTRODUCTION

Increases in computed tomography (CT) use may not always reflect clinical need or improve outcomes. This study aimed to demonstrate how population level data can be used to identify variations in care between patient groups, by analysing system-level changes in CT use around the diagnosis of new conditions.

METHODS

Retrospective repeated cross-sectional observational study using West Australian linked administrative records, including 504,723 adults diagnosed with different conditions in 2006, 2012 and 2015. For 90 days pre/post diagnosis, CT use (any and 2+ scans), effective dose (mSv), lifetime attributable risk (LAR) of cancer incidence and mortality from CT, and costs were assessed.

RESULTS

CT use increased from 209.4 per 1000 new diagnoses in 2006 to 258.0 in 2015; increases were observed for all conditions except neoplasms. Healthcare system costs increased for all conditions but neoplasms and mental disorders. Effective dose increased substantially for respiratory (+2.5 mSv, +23.1%, P < 0.001) and circulatory conditions (+2.1 mSv, +15.4%, P < 0.001). The LAR of cancer incidence and mortality from CT increased for endocrine (incidence +23.4%, mortality +18.0%) and respiratory disorders (+21.7%, +23.3%). Mortality LAR increased for circulatory (+12.1%) and nervous system (+11.0%) disorders. The LAR of cancer incidence and mortality reduced for musculoskeletal system disorders, despite an increase in repeated CT in this group.

CONCLUSIONS

Use and costs increased for most conditions except neoplasms and mental and behavioural disorders. More strategic CT use may have occurred in musculoskeletal conditions, while use and radiation burden increased for respiratory, circulatory and nervous system conditions. Using this high-level approach we flag areas requiring deeper investigation into appropriateness and value of care.

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.

How much should we be concerned about cumulative effective doses in medical imaging?

The International Atomic Energy Agency issued a statement calling for action to strengthen the radiation protection of patients undergoing recurrent imaging. This followed reports of patients receiving cumulative effective doses over 100 mSv from multiple computed tomography examinations. In order to evaluate excess risks of cancer incidence among UK patients, data from an exposure management system covering three hospitals within one trust have been studied over 5½ years. Cumulative effective doses for 105 757 patients, from whom 719 (0.68%) received effective dose over 100 mSv, have been analysed using age and sex specific risk factors for stochastic effects. Two cancers might be expected to be initiated in the patients receiving over 100 mSv, while five might be expected to develop cancer among patients receiving 50-100 mSv. However, the calculations ignore health conditions for which the patients are being treated that may shorten their lives, and rely on the linear-no-threshold dose-effect model which is a subject of debate, so they are likely to overestimate cancer incidence. If health of the patients receiving >100 mSv is taken into account, the risk of mortality from cancer initiated by medical exposure might be the order of 1 in 2000. Recommendations on further strengthening of optimisation should be applied to imaging procedures for all patients with special focus on those performed on children and adolescents.

Increased Postoperative Use of Computed Tomography Following Emergency Surgery for Ileocaecal Crohn Disease

INTRODUCTION

Multiple imaging modalities are often required for the relapsing nature of Crohn disease (CD). Computed tomography (CT) offers a rapid acquisition of images and shows high specificity and sensitivity. However, CT imaging exposes to a higher dose of ionizing radiation than other abdominal imaging modalities. The aim of this study was to compare the use of preoperative and postoperative CT scan in patients undergoing emergency and elective surgery for CD.

METHODS

All patients undergoing emergency and elective surgery for ileocaecal CD January 2014 to December 2018 were included in this prospective observational study. The study objective was to evaluate the frequency of use of CT scan perioperatively with the number and findings of preoperative and postoperative CT being the primary outcomes. The secondary outcomes were operating time, length of hospital stay, reoperations, and rehospitalization.

RESULTS

A total of 75 patients were included, 33 in the emergency group (43%) and 44 in the elective group (57%). There was a higher use of preoperative CT scan in the emergency surgery group, with 14 patients (42%) having a CT scan before surgery compared with 2 (5%) in the elective group (P=0.14). Thirteen patients (39.4%) had a postoperative CT scan in the emergency surgery group, compared with 10 patients (23.8%) in the elective surgery group.

CONCLUSION

Patients undergoing emergency surgery for CD are at increased risk of exposure to ionizing radiations due to high perioperative use of CT scan.

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.

Advanced imaging techniques for small bowel Crohn's disease: what does the future hold?

Treatment of Crohn's disease (CD) is intrinsically reliant on imaging techniques, due to the preponderance of small bowel disease and its transmural pattern of inflammation. Ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) are the most widely employed imaging methods and have excellent diagnostic accuracy in most instances. Some limitations persist, perhaps the most clinically relevant being the distinction between inflammatory and fibrotic strictures. In this regard, several methodologies have recently been tested in animal models and human patients, namely US strain elastography, shear wave elastography, contrast-enhanced US, magnetization transfer MRI and contrast dynamics in standard MRI. Technical advances in each of the imaging methods may expand their indications. The addition of oral contrast to abdominal US appears to substantially improve its diagnostic capabilities compared to standard US. Ionizing dose-reduction methods in CT can decrease concern about cumulative radiation exposure in CD patients and diffusion-weighted MRI may reduce the need for gadolinium contrast. Clinical indexes of disease activity and severity are also increasingly relying on imaging scores, such as the recently developed Lémann Index. In this review we summarize some of the recent advances in small bowel CD imaging and how they might affect clinical practice in the near future.

Ionizing diagnostic radiation exposure in patients with Crohn's disease: A retrospective study in a medium hospital and its predictive factors

INTRODUCTION

It is estimated that diagnostic medical radiation exposure may be responsable for 0.5-2% of cancers worldwide. Because of the relapsing course of Crohn's disease (CD), these patients usually requiere multiple ionizing radiation test.

OBJECTIVE

Stimating the total cumulative effective dose received by our CD patients and identifying the risk factors associated with the exposure to a cumulative effective dose due to the disease (CEED) > 50mSv.

MATERIALS AND METHODS

Retrospective cohort study (2001-2014).

POPULATION

patients with CD. Risk dose >50mSv. For calculating de cumulative effective dose and the CEED, all the ionizing test done were taken. For identifying predictive factors for receiving a CEDD >50mSv, an univariate and a multivariate logistic regression analyses were performed using a >50mSv dose as dependent variable.

RESULTS

Of the 267 patients analyzed the 24.6% of them received a cumulative effective dose > 50mSv and the 15.2% a CEED>50mSv. In the multivariate analysis, the following variables were identified as independent predictors associated with a CEDD >50mSv: major surgery (OR= 2.1; IC_95% [1.1-3.8]; p=.019) and severity (OR= 20.6; IC_95% [4.5-94.8]; p<.01).

CONCLUSIONS

Patients with CD are more at risk of receiving risk CEED, so it would be advisable to monitor the cumulative effective dose received to anticipate our intervention in order to avoid reaching that dose. The ultrasounds and abdominal resonance enterography are alternatives in these cases, although their accessibility is limited in some centers.

Bowel Thickening in Crohn's Disease: Fibrosis or Inflammation? Diagnostic Ultrasound Imaging Tools

The high frequency of intestinal strictures in patients with Crohn's disease and the different treatment approaches specific for each type of stenosis make the differentiation between fibrotic and inflammatory strictures crucial in management of the disease. However, there is no standardized approach to evaluate and discriminate intestinal strictures, and until now, there was no established cross-sectional imaging modality to detect fibrosis. New techniques, such as contrast-enhanced ultrasound and sonoelastography allow the assessment of vascularization and mechanical properties of stenotic bowel tissue, respectively. These techniques have shown great potential to characterize strictures in Crohn's disease. The aim of this review is to sum up the current knowledge on bowel ultrasound tools to discriminate inflammatory from fibrotic stenosis in Crohn's disease considering the most recent published studies in the field.

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.