• Bowel vasculopathy
• Inferior mesenteric artery
• Outcome measures
• Pathogenesis
• Scleroderma
• Superior mesenteric artery
• Systemic sclerosis

• Humans
• Scleroderma, Systemic/physiopathology
• Scleroderma, Systemic/complications
• Scleroderma, Systemic/diagnostic imaging
• Cross-Sectional Studies
• Female
• Ultrasonography, Doppler/methods
• Male
• Middle Aged
• Cohort Studies
• Adult
• Aged
• Mesenteric Arteries/physiopathology
• Mesenteric Arteries/diagnostic imaging

Four-dimensional (4D) flow magnetic resonance imaging (MRI) is used as a noninvasive modality for assessing hemodynamic information with neurovascular and body applications. The application of 4D flow MRI for assessment of bowel disease in children has not been previously described.

To determine feasibility of superior mesenteric venous and arterial flow quantitation in pediatric patients using 4D flow MRI.

Nine pediatric patients (7-14 years old, 5 male and 4 female) with history or suspicion of bowel pathology, who underwent magnetic resonance (MR) enterography with 4D flow MR protocol from November 2022 to October 2023. Field strength/sequence: 3T MRI using 4D flow MR protocol. Flow velocity and peak speed measurements were performed by two diagnostic radiologists placing the region of interest in perpendicular plane to blood flow on each cross section of superior mesenteric artery (SMA) and superior mesenteric vein (SMV) at three predetermined levels. Bland-Altman analysis, showed good agreement of flow velocity and peak speed measurements of SMV and SMA between two readers.

Mean SMV flow velocity increased from proximal to mid to distal (0.14 L/minute, 0.17 L/minute, 0.22 L/minute respectively). Mean SMA flow velocity decreased from proximal to mid to distal (0.35 L/minute, 0.27 L/minute, 0.21 L/minute respectively). Observed agreement was good for flow velocity measurements of SMV (mean bias -0.01 L/minute and 95% limits of agreement, -0.09 to 0.08 L/minute) and SMA (mean bias -0.03 L/minute and 95% limits of agreement, -0.23 to 0.17 L/minute) between two readers. Good agreement for peak speed measurements of SMV (mean bias -1.2 cm/second and 95% limits of agreement, -9.4 to 7.0 cm/second) and SMA (mean bias -3.2 cm/second and 95% limits of agreement, -31.4 to 24.9 cm/second).

Flow quantitation using 4D Flow is feasible to provide hemodynamic information for SMV and SMA in children.

• Four-dimensional flow magnetic resonance imaging
• Superior mesenteric artery
• Superior mesenteric vein
• Bowel disease
• Mesenteric vessel flow analysis

Intestinal ultrasound (IUS) is a non-invasive, real-time, cross-sectional imaging tool that can be used at the point-of-care to assess disease activity in patients with Crohn’s disease or ulcerative colitis. IUS promotes quick and impactful treatment decisions that can modify disease progression and enhance patient compliance. This review will summarize the technical aspects of IUS, the evidence to support the use of IUS in disease activity monitoring, the comparison of IUS to current standard of care monitoring modalities such as colonoscopy and calprotectin, and the optimal positioning of IUS in a tight-control monitoring strategy.

• Crohn’s disease
• Ulcerative colitis
• Disease monitoring
• Intestinal ultrasound

• Humans
• Inflammatory Bowel Diseases/diagnostic imaging
• Intestines/diagnostic imaging
• Crohn Disease/diagnostic imaging
• Colitis, Ulcerative/diagnostic imaging
• Clinical Decision-Making

Crohn’s disease (CD) is a chronic inflammatory bowel disease that affects a wide age range. Hence, CD patients receive a variety of drugs over their life beyond those used for CD itself. The changes to the integrity of the intestine and its drug metabolising enzymes and transporters (DMETs) can alter the oral bioavailability of drugs. However, there are other changes in systems parameters determining the fate of drugs in CD, and understanding these is essential for dose adjustment in patients with CD.

The current analysis gathered all the available clinical data on the kinetics of drugs in CD (by March 2021), focusing on orally administered small molecule drugs. A meta-analysis of the systems parameters affecting oral drug pharmacokinetics was conducted. The systems information gathered on intestine, liver and blood proteins and other physiological parameters was incorporated into a physiologically based pharmacokinetic (PBPK) platform to create a virtual population of CD patients, with a view for guiding dose adjustment in the absence of clinical data in CD.

There were no uniform trends in the reported changes in reported oral bioavailability. The nature of the drug as well as the formulation affected the direction and magnitude of variation in kinetics in CD patients relative to healthy volunteers. Even for the same drug, the reported changes in exposure varied, possibly due to a lack of distinction between the activity states of CD. The highest alteration was seen with S-verapamil and midazolam, 8.7- and 5.3-fold greater exposure, respectively, in active CD patients relative to healthy volunteers. Only one report was available on liver DMETs in CD, and indicated reduced CYP3A4 activity. In a number of reports, mRNA expression of DMETs in the ileum and colon of CD patients was measured, focussing on P-glycoprotein (p-gp) transporter and CYP3A4 enzyme, and showed contradictory results. No data were available on protein expression in duodenum and jejunum despite their dominant role in oral drug absorption.

There are currently inadequate dedicated clinical or quantitative proteomic studies in CD to enable predictive PBPK models with high confidence and adequate verification. The PBPK models for CD with the available systems parameters were able to capture the major physiological influencers and the gaps to be filled by future research. Quantification of DMETs in the intestine and the liver in CD is warranted, alongside well-defined clinical drug disposition studies with a number of index drugs as biomarkers of changes in DMETs in these patients, to avoid large-scale dedicated studies for every drug to determine the effects of disease on the drug’s metabolism and disposition and the consequential safety and therapeutic concerns.

The online version contains supplementary material available at 10.1007/s40262-022-01169-4.

Transabdominal ultrasound (TAUS) is useful in all aspects of lesion screening, monitoring activity, or treating/diagnosing any related complications of inflammatory bowel disease. Its ability to screen or diagnose complications is almost the same as that of other methods, such as CT or MRI. Moreover, its noninvasiveness makes it a first-line examination method. A TAUS image depicting ulcerative colitis will show large intestinal wall thickening that is continuous from the rectum, which is mainly due to mucosal layer thickening, while for Crohn’s disease, a TAUS image is characterized by a diversity in the areas affected, distribution, and layer structure. Indicators of activity monitoring include wall thickness, wall structure, and vascular tests that use Doppler ultrasound or contrast agents. While all of these have been reported to be useful, at this time, no single parameter has been established as superior to others; therefore, a comprehensive evaluation of these parameters is justified. In addition, evaluating the elasticity of lesions using elastography is particularly useful for distinguishing between fibrous and inflammatory stenoses. However, the lack of objectivity is the biggest drawback of using ultrasound. Standardizing and popularizing the ultrasound process will be necessary, including scanning methods, equipment settings, and image analysis.

• Crohn's disease
• Diagnosis
• Monitoring
• Ulcerative colitis
• Ultrasound

Crohn’s disease (CD) is characterized by a remitting and relapsing course. Longstanding active CD may result in accumulating intestinal damage and disease-related complications. In contrast, mucosal healing is associated with significant improvement in the health-related quality of life, longer periods of disease remission and lower risk of disease progression, complications, hospitalizations, intestinal surgeries, as well as a lower risk of developing colorectal cancer. Mucosal healing, the new treatment endpoint in CD, made necessary the development of noninvasive, accurate, objective and reliable tools for the evaluation of CD activity. Ileocolonoscopy with biopsies remains the reference standard method for the evaluation of the colonic and terminal ileal mucosa. However, it is an invasive procedure with a low risk of complications, allowing the investigation of only a small part of the small bowel mucosa without being able to assess transmural inflammation. These disadvantages limit its role in the frequent follow up of CD patients. In this review, we present the currently available biomarkers and imaging modalities for the noninvasive assessment of CD activity.

• Crohn’s disease
• disease activity
• monitoring

• Inflammatory bowel diseases
• abdominal ultrasound
• crohn's disease.
• doppler ultrasound
• severity
• ulcerative colitis

• Adult
• Colitis, Ulcerative/diagnostic imaging
• Crohn Disease/diagnostic imaging
• Humans
• Inflammatory Bowel Diseases/diagnostic imaging
• Mesenteric Artery, Inferior/diagnostic imaging
• Middle Aged
• Ultrasonography

• IBD
• Inflammatory bowel disease
• Intestinal ultrasound

• Contrast Media/administration & dosage
• Humans
• Inflammatory Bowel Diseases/complications
• Inflammatory Bowel Diseases/diagnostic imaging
• Intestines/diagnostic imaging
• Prognosis
• Ultrasonography

To investigate the diagnostic accuracy of ultrasound for evaluation of inflammatory activity in patients with Crohn’s disease (CD).

Fifty-six patients with histologically proven CD (39 with active, 17 with inactive disease) and 30 healthy volunteers as a control group were enrolled in the study at WeiFang People’s Hospital, Weifang Province, China from October 2012 to December 2014. Bowel wall thickness, and vascularity pattern were measured by Doppler ultrasound.

There was a significant difference in flow volume of the superior mesenteric artery (585 ± 235 ml/min) in the patients with active disease, compared with those with inactive disease (401 ± 238 ml/min) and the control group (390 ± 189 ml/min, p<0.001). Wall thickness was 5.1 ± 1.5 mm in the active CD group, 3.3 ± 1.6 mm in the inactive disease group (p<0.001) and <3 mm in the control group. Resistance index in the thickened bowel wall showed some differences: 0.68 ± 0.05 in the active disease group, 0.78 ± 0.08 in the inactive disease group, and 0.85 ± 0.07 in the control group (p<0.05).

Doppler ultrasound is a useful diagnostic tool in detecting CD and assessing inflammatory activity.

• Adult
• China
• Cohort Studies
• Crohn Disease/diagnostic imaging
• Crohn Disease/pathology
• Female
• Gastrointestinal Tract/blood supply
• Gastrointestinal Tract/diagnostic imaging
• Humans
• Male
• Mesenteric Artery, Superior/diagnostic imaging
• Middle Aged
• Prospective Studies
• Sensitivity and Specificity
• Ultrasonography, Doppler

• CDAI
• CDEIS
• CT-enterography
• Crohn’s disease
• MR-enterography
• MaRIA
• SES-CD
• disease activity
• therapeutic monitoring

• Angiogenesis
• Contrast-enhanced ultrasound
• Crohn's disease
• Splanchnic hemodynamics
• Ultrasound
• Vascular endothelial growth factor

• Adolescent
• Adult
• Blood Flow Velocity/physiology
• Contrast Media
• Crohn Disease/blood
• Crohn Disease/diagnostic imaging
• Crohn Disease/physiopathology
• Female
• Hemodynamics/physiology
• Humans
• Image Enhancement
• Intestines/blood supply
• Intestines/diagnostic imaging
• Intestines/physiopathology
• Male
• Mesenteric Artery, Superior/diagnostic imaging
• Mesenteric Artery, Superior/physiopathology
• Middle Aged
• Nitric Oxide/blood
• Splanchnic Circulation/physiology
• Tumor Necrosis Factor-alpha/blood
• Ultrasonography, Doppler
• Vascular Endothelial Growth Factor A/blood
• Young Adult

• Abdomen/diagnostic imaging
• Abdomen/pathology
• Adolescent
• Adult
• Aged
• Contrast Media/administration & dosage
• Crohn Disease/diagnosis
• Crohn Disease/pathology
• Endosonography/methods
• Female
• Humans
• Ileum/pathology
• Inflammation/pathology
• Intestinal Mucosa/pathology
• Magnetic Resonance Imaging/methods
• Male
• Middle Aged
• Prospective Studies
• ROC Curve
• Sensitivity and Specificity
• Young Adult

• Complication
• Guidelines
• Intestine
• Pediatrics
• Ultrasonography

• Child
• Colitis, Ulcerative/diagnostic imaging
• Colitis, Ulcerative/therapy
• Contrast Media
• Crohn Disease/diagnostic imaging
• Crohn Disease/therapy
• Humans
• Intestines/diagnostic imaging
• Predictive Value of Tests
• Prognosis
• Risk Factors
• Ultrasonography, Doppler, Color

• Crohn's disease
• abdominal abscess
• computerized tomography
• disease assessment
• fistula
• imaging modalities
• intestinal ultrasound
• magnetic resonance imaging
• stricture
• ulcerative colitis

Several radiological and endoscopic techniques are now available for the study of inflammatory bowel diseases. In everyday practice, the choice of the technique to be used depends upon its availability and a careful evaluation of diagnostic accuracy, clinical usefulness, safety, and cost. The recent development of innovative and noninvasive imaging techniques has led to a new and exciting area in the exploration of the gastrointestinal tract, especially in Crohn's disease patients by using ultrasound with oral or intravenous contrast.

Crohn's disease is a chronic granulomatous inflammatory disease of the gastrointestinal tract, which can involve almost any segment from the mouth to the anus. Typically, Crohn's lesions attain segmental and asynchronous distribution with varying levels of seriousness, although the sites most frequently involved are the terminal ileum and the proximal colon. A single gold standard for the diagnosis of CD is not available and the diagnosis of CD is confirmed by clinical evaluation and a combination of endoscopic, histological, radiological, and/or biochemical investigations. In recent years, many studies have been performed to investigate the diagnostic potential of less invasive and more patient-friendly imaging modalities in the evaluation of Crohn's disease including conventional enteroclysis, ultrasonography, color-power Doppler, contrast-enhanced ultrasonography, multidetector CT enteroclysis, MRI enteroclysis, and 99mTc-HMPAO-labeled leukocyte scintigraphy. The potential diagnostic role of each imaging modality has to be considered in different clinical degrees of the disease, because there is no single imaging technique that allows a correct diagnosis and may be performed with similar results in every institution. The aim of this paper is to point out the advantages and limitations of the various imaging techniques in patients with suspected or proven Crohn's disease.