• Crohn’s disease
• imaging
• inflammatory bowel disease
• radiation

• 640-slice CT
• OSLD
• abdominal CT
• alderson-rando anthropomorphic phantom
• radiation dose

• Female
• Humans
• Male
• Phantoms, Imaging
• Radiation Dosage
• Radiation Protection
• Tomography Scanners, X-Ray Computed
• Tomography, X-Ray Computed

• , X-ray computed
• Abdomen
• Emergencies
• Pelvis
• Tomography
• Ultra-low dose CT

• CT
• Crohn's disease
• Cystic fibrosis
• Dose reduction

• Abdominal pain
• Bowel obstruction
• CT abdomen
• Ultra low dose

• Abdomen
• Imaging
• Phantoms
• Radiation dosage
• Thorax
• Tomography, X-ray computed

• Humans
• Phantoms, Imaging
• Radiation Dosage
• Radiography, Abdominal/instrumentation
• Radiography, Abdominal/methods
• Radiography, Thoracic/instrumentation
• Radiography, Thoracic/methods
• Signal-To-Noise Ratio
• Tomography, X-Ray Computed/instrumentation
• Tomography, X-Ray Computed/methods

• CT abdomen
• Filtered back projection
• Forward projected model-based
• Iterative reconstruction
• Radiation dose
• Sub-milli-Sievert

• Acute abdominal imaging
• Computed tomography
• Dose optimization
• Iterative reconstruction
• Radiation dose reduction

• Magnetic resonance imaging
• Mucopolysaccharidoses
• Multidetector computed tomography
• Musculoskeletal involvement
• Radiography
• Ultrasound

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.

• 1 millisievert
• CT enterography
• Crohn’s disease
• Half-dose
• Iterative reconstruction
• Radiation reduction

• Adolescent
• Adult
• Contrast Media
• Crohn Disease/diagnostic imaging
• Crohn Disease/pathology
• Female
• Humans
• Image Interpretation, Computer-Assisted/methods
• Inflammation/diagnostic imaging
• Inflammation/pathology
• Intestines/diagnostic imaging
• Intestines/pathology
• Iohexol/analogs & derivatives
• Male
• Middle Aged
• Prospective Studies
• Radiation Dosage
• Radiographic Image Interpretation, Computer-Assisted/methods
• Reproducibility of Results
• Sensitivity and Specificity
• Tomography, X-Ray Computed/methods
• Young Adult

• abdominopelvic
• cadaver
• iterative reconstruction
• radiation exposure
• tomography, X-ray computed

• Aged
• Female
• Humans
• Lumbar Vertebrae/diagnostic imaging
• Lumbar Vertebrae/injuries
• Male
• Middle Aged
• Multidetector Computed Tomography/methods
• Radiation Dosage
• Radiographic Image Interpretation, Computer-Assisted/methods
• Retrospective Studies
• Spinal Fractures/diagnostic imaging

• CT enterography
• Crohn disease
• biomarkers
• disease activity
• inflammatory bowel disease

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.

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).

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.

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.

• Inflammatory bowel disease
• Crohn’s disease
• computerized tomography
• magnetic resonance imaging

To develop guidelines describing a standardised approach to patient preparation and acquisition protocols for magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) of the small bowel and colon, with an emphasis on imaging inflammatory bowel disease.

An expert consensus committee of 13 members from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) and European Society of Paediatric Radiology (ESPR) undertook a six-stage modified Delphi process, including a detailed literature review, to create a series of consensus statements concerning patient preparation, imaging hardware and image acquisition protocols.

One hundred and fifty-seven statements were scored for agreement by the panel of which 129 statements (82 %) achieved immediate consensus with a further 19 (12 %) achieving consensus after appropriate modification. Nine (6 %) statements were rejected as consensus could not be reached.

These expert consensus recommendations can be used to help guide cross-sectional radiological practice for imaging the small bowel and colon.

• Cross-sectional imaging is increasingly used to evaluate the bowel

• Image quality is paramount to achieving high diagnostic accuracy

• Guidelines concerning patient preparation and image acquisition protocols are provided

• Computed tomography
• Crohn disease
• Magnetic resonance imaging
• Small bowel
• Ultrasound

• Hounsfield units
• computed tomography
• image reconstruction
• iterative reconstruction
• radiation

To assess the effect of neutral (NC) and positive (PC) oral contrast use on patient dose in low-dose abdominal computed tomography (CT).

Low-dose clinically indicated CTs were performed on 79 Crohn’s patients (35 = PC, 1 L 2% gastrografin; 44 = NC, 1.5 L polyethylene glycol). Scanner settings for both acquisitions were identical apart from 25 s difference in intravenous contrast timing. Body mass index (BMI), scan-ranges, dose-length product and size-specific dose estimated were recorded. Data was reconstructed with pure model-based iterative reconstruction. Image quality was objectively and subjectively analysed. Data analysis was performed with Statistical Package for Social Scientists.

Higher doses were seen in neutral contrast CTs (107.60 ± 78.7 mGy.cm, 2.47 ± 1.21 mGy vs 85.65 ± 58.2 mGy.cm, 2.18 ± 0.96 mGy). The difference was significant in 2 of 4 BMI groups and in those that had both NC and PC investigations. Image-quality assessment yielded 6952 datapoints. NC image quality was significantly superior (P < 0.001) (objective noise, objective signal to noise ratio, subjective spatial resolution, subjective contrast resolution, diagnostic acceptability) at all levels. NC bowel distension was significantly (P < 0.001) superior.

The use of polyethylene glycol as a neutral OC agent leads to higher radiation doses than standard positive contrast studies, in low dose abdominal CT imaging. This is possibly related to the osmotic effect of the agent resulting in larger intraluminal fluid volumes and resultant increased overall beam attenuation.

• Radiation dose
• Low dose computed tomography
• Abdominal imaging
• Oral contrast
• Computed tomography

AIM: To quantify cumulative effective dose of intensive care unit (ICU) patients attributable to diagnostic imaging.

METHODS: This was a prospective, interdisciplinary study conducted in the ICU of a large tertiary referral and level 1 trauma center. Demographic and clinical data including age, gender, date of ICU admission, primary reason for ICU admission, APACHE II score, length of stay, number of days intubated, date of death or discharge, and re-admission data was collected on all patients admitted over a 1-year period. The overall radiation exposure was quantified by the cumulative effective radiation dose (CED) in millisieverts (mSv) and calculated using reference effective doses published by the United Kingdom National Radiation Protection Board. Pediatric patients were selected for subgroup-analysis.

RESULTS: A total of 2737 studies were performed in 421 patients. The total CED was 1704 mSv with a median CED of 1.5 mSv (IQR 0.04-6.6 mSv). Total CED in pediatric patients was 74.6 mSv with a median CED of 0.07 mSv (IQR 0.01-4.7 mSv). Chest radiography was the most commonly performed examination accounting for 83% of all studies but only 2.7% of total CED. Computed tomography (CT) accounted for 16% of all studies performed and contributed 97% of total CED. Trauma patients received a statistically significant higher dose [median CED 7.7 mSv (IQR 3.5-13.8 mSv)] than medical [median CED 1.4 mSv (IQR 0.05-5.4 mSv)] and surgical [median CED 1.6 mSv (IQR 0.04-7.5 mSv)] patients. Length of stay in ICU [OR = 1.12 (95%CI: 1.079-1.157)] was identified as an independent predictor of receiving a CED greater than 15 mSv.

CONCLUSION: Trauma patients and patients with extended ICU admission times are at increased risk of higher CEDs. CED should be minimized where feasible, especially in young patients.

• Cumulative effective dose
• Pediatric patients
• Computed tomography
• Radiation dose
• Intensive care unit

Cystic fibrosis (CF) is the most common autosomal recessive disease of the Caucasian population worldwide, with respiratory disease remaining the most relevant source of morbidity and mortality. Computed tomography (CT) is frequently used for monitoring disease complications and progression. Over the last fifteen years there has been a six-fold increase in the use of CT, which has lead to a growing concern in relation to cumulative radiation exposure. The challenge to the medical profession is to identify dose reduction strategies that meet acceptable image quality, but fulfil the requirements of a diagnostic quality CT. Dose-optimisation, particularly in CT, is essential as it reduces the chances of patients receiving cumulative radiation doses in excess of 100 mSv, a dose deemed significant by the United Nations Scientific Committee on the Effects of Atomic Radiation. This review article explores the current trends in imaging in CF with particular emphasis on new developments in dose optimisation.

• Cystic fibrosis
• Dose optimization
• Computed tomography
• Dose
• Ionising radiation
• Kalydeco

Crohn’s disease is a type of inflammatory bowel disease affecting estimated 4 million people worldwide. Therapy stratification of Crohn’s disease (CD) is mainly based on the inflammatory activity being assessed by endoscopic biopsy and clinical criteria. Cross-sectional imaging allows for the assessment of structural characteristics of the entire gastrointestinal tract including small bowel loops and may provide potential non-invasive image-based biomarkers for the inflammatory activity of CD. The aim of this study was to explore the predictive value of Computed Tomography-based morphologic patterns for inflammatory activity in CD.

42 patients diagnosed with CD were included in a retrospective study (13 male, 29 female, median age 32 years). Abdominal CT imaging was carried out on symptomatic patients at a single institution 0–10 days prior to endoscopic biopsy or surgery using a protocol optimized for the characterization of structural bowel alterations. Image data were initially reviewed independently by three radiologists and discrepancies were settled in consensus with a focus on mesenteric fat stranding and combing, mesenteric adenopathy, mesenteric abscess, intraperitoneal free fluid, fistula, skip lesions, highest wall thickness and the localization of the affected bowel. The extent of inflammatory activity in the bowel wall was determined subsequently by histological analysis.

All intestinal and extraintestinal CT findings except the mesenteric comb sign showed a tendency towards higher extent or prevalence in patients with high histological inflammatory activity score, especially median bowel wall thickness (6.0 mm vs. 3.5 mm), mesenteric abscesses (32% vs. 0%) and mesenteric adenopathy (94% vs. 45%). Spearman rank order correlation coefficient indicated a significant correlation of bowel wall thickness (r = 0.40, p < 0.05), mesenteric adenopathy (r = 0.54, p < 0.05), mesenteric abscess (r = 0.33, p < 0.05) and mesenteric fat stranding (r = 0.33, p < 0.05) with the histological inflammatory activity score.

CT-based biomarkers including wall thickness, mesenteric fat stranding, mesenteric lymphadenopathy and mesenteric abscess positively correlated with the histological inflammatory activity score and therefore provided additional information for therapy stratification in symptomatic patients with CD, particularly as most of these biomarkers are hidden from endoscopy.

• CT Crohn Small bowel Computed Tomography
• Histopathology

• CT
• Crohn disease
• iterative reconstruction
• low-dose CT
• model-based iterative reconstruction

• Abdominopelvic CT
• Hybrid iterative reconstruction
• Image noise
• Left-sided colonic diverticulitis
• Reduced radiation dose

Background: The diagnosis of inflammatory bowel disease (IBD) in children and adolescents is based on the integration of clinical, biological, endoscopic, histological and radiological data. Methods: The most important part of the diagnosis is the histology, which is acquired by endoscopy. Imaging of the small bowel has changed in recent years, but the imaging goals are primarily to determine the extent of small bowel involvement, assess complications and define candidates for surgery. Imaging techniques are divided into conventional and cross-sectional ones. Results: The spectrum of imaging findings of cross-sectional techniques is discussed, emphasising the advantages and limitations of each technique, acknowledging the specificities of the paediatric population. Cross-sectional techniques have advanced the ability to diagnose and monitor inflammatory disease of the small bowel. Conclusion: MR enterography is the technique of choice in children with known IBD, for the investigation of the small bowel and the whole GI tract. US should be the first choice examination in children with suspected IBD, while CT should be reserved for cases in which MRI is contraindicated or in acute emergency situations when US is inadequate.

• Cross-sectional imaging of the small bowel is essential in paediatric IBD.

• Endoscopy is unable to assess extramural disease and examine the entire small bowel.

• US should be the first choice examination in children with suspected IBD.

• MR enterography is the technique of choice in children with known IBD.

• There are still controversies regarding the prediction of disease activity or fibrosis.

• Abdominal MDCT
• Iterative reconstruction technique
• Radiation dose reduction