Beyond moulage sign and TTG levels: the role of cross-sectional imaging in celiac sprue

CT and MR Enterography in the Evaluation of Celiac Disease

Celiac disease is a common inflammatory disease of the small bowel that induces mucosal intestinal lesions. The disease is mediated by an immune response and triggered by the ingestion of gluten in genetically predisposed individuals. Gluten contains gliadin, a component found mostly in wheat, barley, and rye. This process leads to gastrointestinal malabsorption with symptoms such as diarrhea, constipation, abdominal pain, and distention. It has a prevalence of 1%-2% in the general adult population, who present with symptoms at any age, but is more frequently found in adult women in the 3rd or 4th decade of life. Recognition of the disease has increased, but it remains a challenge to diagnose. CT and MR enterography are noninvasive studies used for evaluation of small bowel neoplasms and inflammatory small bowel pathologic conditions such as celiac disease. The authors review the spectrum of intestinal and extraintestinal findings of celiac disease at CT and MR enterography, as well as its complications, and the importance of recognizing certain imaging features that help in the diagnosis of celiac disease. More common and specific findings of celiac disease such as inversion of the jejunoileal fold pattern and mesenteric lymphadenopathy are reviewed. More uncommon entities that are more frequently associated with refractory or untreated celiac disease, such as ulcerative jejunoileitis, cavitary mesenteric lymph node syndrome, and malignancies including small bowel adenocarcinoma and lymphoma, are described. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. The slide presentation from the RSNA Annual Meeting is available for this article.

Autoimmune disorders of the gastrointestinal tract: Review of radiological appearances

Autoimmune gastrointestinal (GI) disorders comprise a heterogeneous group of diseases with non-specific clinical manifestations. These are divided into primary and secondary. A high index of clinical suspicion complemented with endoscopic and radiological imaging may allow early diagnosis. Due to the relatively low incidence of autoimmune disorder, the imaging literature is sparse. In this review, we outline the pathogenesis, classification, and imaging appearances of autoimmune GI disorders.

Cross-sectional imaging: current status and future potential in adult celiac disease

Celiac disease (CD), triggered by exposure to gluten in genetically susceptible individuals, is an immune-mediated small bowel disease affecting about 1% of the population worldwide. But the prevalence of CD varies with age, sex, and location. A strict gluten-free diet remains the primary treatment for CD, currently. Most of patients with CD respond well to gluten-free diet with good prognosis, while some patients fail to get symptomatic relief or histological remission (e.g., nonresponsive or refractory CD). Because of heterogeneous clinical appearance, the diagnosis of CD is difficult. Moreover, malignant complications and poor outcomes accompanied with refractory CD present great challenges in disease management. Over the past three decades, cross-sectional imaging techniques (computed tomography [CT] and magnetic resonance imaging [MRI]) play an important role in small bowel inflammatory and neoplastic diseases. Compared with endoscopic techniques, cross-sectional imaging permits clearly presentation of both intraluminal and extraluminal abnormalities. It provides vascular and functional information, thus improving the possibility as diagnostic and follow-up tool. The value of cross-sectional imaging for patients with suspected or confirmed CD has been gradually demonstrated. Studies revealed that certain features suggested by cross-sectional imaging could help to establish the early diagnosis of CD. Besides, the potential contributions of cross-sectional imaging may lie in the evaluation of disease activity and severity, which helps guiding management strategies. The purpose of this review is to provide current overviews and future directions of cross-sectional imaging in adult CD, thus facilitating the understanding and application in clinical practice. CLINICAL RELEVANCE STATEMENT: In this review, we systematically summarized the existing knowledge of cross-sectional imaging in adult CD and analyzed their possible roles in clinical practice, including disease diagnosis, complication identification, treatment evaluation, and prognostic prediction. KEY POINTS: • Regarding a condition described as "celiac iceberg", celiac disease remains underdiagnosed and undertreated. • Cross-sectional imaging is helpful in clinical management of celiac disease, including disease diagnosis, complication identification, treatment evaluation, and prognostic prediction. • Cross-sectional imaging should be considered as the valuable examination in patients suspected from celiac disease.

Imaging More than Skin-Deep: Radiologic and Dermatologic Presentations of Systemic Disorders

Background: Cutaneous manifestations of systemic diseases are diverse and sometimes precede more serious diseases and symptomatology. Similarly, radiologic imaging plays a key role in early diagnosis and determination of the extent of systemic involvement. Simultaneous awareness of skin and imaging manifestations can help the radiologist to narrow down differential diagnosis even if imaging findings are nonspecific. Aims: To improve diagnostic accuracy and patient care, it is important that clinicians and radiologists be familiar with both cutaneous and radiologic features of various systemic disorders. This article reviews cutaneous manifestations and imaging findings of commonly encountered systemic diseases. Conclusions: Familiarity with the most disease-specific skin lesions help the radiologist pinpoint a specific diagnosis and consequently, in preventing unnecessary invasive workups and contributing to improved patient care.

Does contrast-enhanced computed tomography raise awareness in the diagnosis of the invisible side of celiac disease in adults?

PURPOSE

This study aimed to evaluate the diagnosis and determine major and minor criteria of celiac disease (CD) with the malabsorption patterns (MABP) in the small intestine and colon on computed tomography (CT) and additional CT findings.

METHODS

This retrospective study was conducted with 116 patients diagnosed with CD, 14 CD patients recovering with treatment, and 35 control patients with non-CD. All patients had CT examinations and histopathological diagnoses. The sensitivity, specificity, PPV, NPV, and accuracy values of each CT finding defined in the literature were statistically evaluated. According to the patient and control groups, the numerical values of the findings and the sensitivity and specificity values were measured according to this cut-off value. The distribution of CT findings according to pathological Marsh data was evaluated in CD patients.

RESULTS

Sensitivity and specificity were found to be higher in small bowel MABP findings, mesenteric hypervascularity, and increased SMV/aorta diameter. There was a numerically significant difference in MDCT findings between the control and pathological Marsh groups. In the ROC analysis performed in terms of the total numerical values of each MDCT finding observed between the groups, it was found that there were more than 7 MDCT findings, 100% sensitivity, and 92% specificity. The presence of four major and three minor criteria or three major and four minor criteria were considered significant.

CONCLUSIONS

Being aware of CT findings below the iceberg that may suggest CD in abdominal CT examinations performed in patients with atypical clinical and malabsorption findings or other nonspecific findings may prevent diagnostic delay and unnecessary procedures.

Non-invasive prediction of persistent villous atrophy in celiac disease

BACKGROUND

Celiac disease (CD) is an immune-mediated enteropathy that is primarily treated with a gluten-free diet (GFD). Mucosal healing is the main target of the therapy. Currently, duodenal biopsy is the only way to evaluate mucosal healing, and non-invasive markers are challenging. Persistent elevation of anti-tissue transglutaminase antibodies (aTTG) is not an ideal predictor of persistent villous atrophy (VA). Data regarding prediction of atrophy using anti-deamidated gliadin peptide antibodies (aDGP) and abdominal ultrasonography are lacking.

AIM

To evaluate the ability of aTTG, aDGP, small bowel ultrasonography, and clinical and laboratory parameters in predicting persistent VA determined using histology.

METHODS

Patients with CD at least 1 year on a GFD and available follow-up duodenal biopsy, levels of aTTG and aDGP, and underwent small bowel ultrasonography were included in this retrospective cohort study. We evaluated the sensitivity, specificity, and positive and negative predictive values of aTTG, aDGP, small bowel ultrasonography, laboratory and clinical parameters to predict persistent VA. A receiver operating characteristic (ROC) curve analysis of antibody levels was used to calculate cut off values with the highest accuracy for atrophy prediction.

RESULTS

Complete data were available for 82 patients who were followed up over a period of four years (2014-2018). Among patients included in the analysis, women (67, 81.7%) were predominant and the mean age at diagnosis was 33.8 years. Follow-up biopsy revealed persistent VA in 19 patients (23.2%). The sensitivity and specificity of aTTG using the manufacturer’s diagnostic cutoff value to predict atrophy was 50% and 85.7%, respectively, while the sensitivity and specificity of aDGP (using the diagnostic cutoff value) was 77.8% and 75%, respectively. Calculation of an optimal cutoff value using ROC analysis (13.4 U/mL for aTTG IgA and 22.6 U/mL for aDGP IgA) increased the accuracy and reached 72.2% [95% confidence interval (CI): 46.5-90.3] sensitivity and 90% (95%CI: 79.5-96.2) specificity for aDGP IgA and 66.7% (95%CI: 41.0-86.7) sensitivity and 93.7% (95%CI: 84.5-98.2) specificity for aTTG IgA. The sensitivity and specificity of small bowel ultrasonography was 64.7% and 73.5%, respectively. A combination of serology with ultrasound imaging to predict persistent atrophy increased the positive predictive value and specificity to 88.9% and 98% for aTTG IgA and to 90.0% and 97.8% for aDGP IgA. Laboratory and clinical parameters had poor predictive values.

CONCLUSION

The sensitivity, specificity, and negative predictive value of aTTG and aDGP for predicting persistent VA improved by calculating the best cutoff values. The combination of serology and experienced bowel ultrasound examination may achieve better accuracy for the detection of atrophy.

Infection History Determines Susceptibility to Unrelated Diseases

Epidemiological data suggest that previous infections can alter an individual's susceptibility to unrelated diseases. Nevertheless, the underlying mechanisms are not completely understood. Substantial research efforts have expanded the classical concept of immune memory to also include long-lasting changes in innate immunity and antigen-independent reactivation of adaptive immunity. Collectively, these processes provide possible explanations on how acute infections might induce long-term changes that also affect immunity to unrelated diseases. Here, we review lasting changes the immune compartment undergoes upon infection and how infection experience alters the responsiveness of immune cells towards universal signals. This heightened state of alert enhances the ability of the immune system to combat even unrelated infections but may also increase susceptibility to autoimmunity. At the same time, infection-induced changes in the regulatory compartment may dampen subsequent immune responses and promote pathogen persistence. The concepts presented here outline how infection-induced changes in the immune system may affect human health.

Malabsorption Syndromes, Vasculitis, and Other Uncommon Diseases

MR enterography is frequently ordered for patients with suspected small bowel disorders. In this article, disease-causing malabsorption, vasculitides, and some of the less common small bowel diseases are reviewed. The clinical presentations, diagnostic criteria, and imaging findings of these diseases are discussed. Because the imaging findings in several small bowel diseases are nonspecific and/or overlap, radiologists must correlate clinical data with imaging to develop a narrower differential diagnosis. The unique or characteristic findings in certain diseases are also emphasized.