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

Recent Trends in Non-Invasive Methods of Diagnosis and Evaluation of Inflammatory Bowel Disease: A Short Review

Inflammatory bowel diseases are a conglomerate of disorders causing inflammation of the gastrointestinal tract, which have gained a significant increase in prevalence in the 21st century. As they present a challenge in the terms of diagnosis as well as treatment, IBDs can present an overwhelming impact on the individual and can take a toll on healthcare costs. Thus, a quick and precise diagnosis is required in order to prevent the high number of complications that can arise from a late diagnosis as well as a misdiagnosis. Although endoscopy remains the primary method of evaluation for IBD, recent trends have highlighted various non-invasive methods of diagnosis as well as reevaluating previous ones. This review focused on the current non-invasive methods in the diagnosis of IBD, exploring their possible implementation in the near future, with the goal of achieving earlier, feasible, and cheap methods of diagnosis as well as prognosis in IBD.

The role of intestinal ultrasound with colour Doppler in predicting the response to biologic therapy in inflammatory bowel disease patients

Introduction

Inflammatory bowel disease patients are exposed to frequent procedures and hospital admissions as well as recurrent need for radiological examinations with a high risk of exposure to radiation and contrast.

Aim

Our objective was to evaluate the role of a combination of both intestinal ultrasound (IUS) and colour Doppler with different parameters for monitoring changes in inflammation over time and to reveal their potential role in the assessment of response to biologic therapy in inflammatory bowel disease (IBD) patients.

Material and methods

Before the induction of biological therapy, IUS together with colour Doppler of the intestine was conducted. Response to therapy was defined following the international guidelines.

Results

A total of 45 patients with histopathological diagnosis of IBD were enrolled in the study. All patients received biological therapy and were assessed for response after 3 months. Out of those patients, 34 (75.6%) had good response while 11 (24.4%) failed to respond to the treatment. Our findings point to a strong association between bowel wall thickening (BWT) and serum albumin, erythrocyte sedimentation rate (ESR), and c-reactive protein (CRP). The overall sensitivity of IUS varied from 54 to 93% when evaluating bowel affection, with a specificity of 97-100%, in comparison to our results, which showed a sensitivity of 64-74% and specificity of 79-82%. Doppler parameters could predict the response to the biologic therapy in IBD patients.

Conclusions

Intestinal ultrasound and colour Doppler provide a safe, non-invasive way to monitor changes in inflammation and blood flow in the digestive tract.

Role of abbreviated non-contrast-enhanced MR-enterography in the evaluation of Crohn's disease activity and complications as an alternative for full protocol contrast-enhanced study: A systematic review and meta-analysis

Background

Crohn's disease (CD) is a chronic disorder that often starts at a young age and involves periods of remission and relapse. Prompt diagnosis of relapses through screening is crucial due to the potential morbid complications of untreated active inflammation. Magnetic resonance enterography (MRE) is a noninvasive technique to screen for active inflammation. The standard protocol involves intravenous injection of contrast agents with potential side effects. Some abbreviated non-contrast-enhanced MRE protocols are proposed as alternatives for conventional MRE to identify active inflammation. Currently, there is controversy regarding the applicability and accuracy of these protocols. This study aims to describe and compare these protocols and evaluate their accuracy in detecting active inflammation and CD complications.

Methods

Results from a systematic search of three databases in August 2022 were queried and screened by abstract and full text. Eligible studies were qualitatively and quantitatively analyzed by diagnostic test accuracy meta-analysis.

Results

59 studies entered the systematic review, and 37 were eligible for meta-analysis. Diffusion-weighted imaging (DWI) and fast T2-weighted (T2w) sequences were most frequently used in abbreviated protocols and showed non-inferior accuracy compared to the full protocol in detecting active inflammation. ADC and qualitative DWI had pooled sensitivity of 90% (CI: 82-95%) and 89% (CI:82-93%) and pooled specificity of 94% (CI: 88-97%) and 89% (CI: 79-94%), respectively for detecting active inflammation. Moreover, T2w and combined T2w+DWI sequences had pooled sensitivity of 80% (CI: 64-90%) and 76% (CI: 61-86%) and pooled specificity of 90% (CI: 80-95%) and 87% (CI: 74 - 94%), respectively. Unenhanced protocols show relatively poor diagnostic accuracy in detecting penetrating complications of CD. Magnetization transfer imaging (MTI) has demonstrated excellent accuracy in detecting fibrosis. High heterogeneity was observed in all subgroups, and accuracy was reported to be highly operator dependent in most studies.

Conclusion

An abbreviated protocol consisting of DWI and fast T2w imaging can potentially replace the full protocol MRE. Full protocol MRE will still have its role in identifying penetrating complications. MTI should be indicated in case of suspected fibrostenotic disease.

Diagnostic value of the microcolon using ultrasonography in small bowel atresia

Background

Microcolon helps diagnose small bowel atresia (SBA) using contrast enema. However, there are no ultrasonography (US) microcolon criteria for diagnosing SBA. Therefore, this study aimed to evaluate colon accuracy and other characteristics for diagnosing SBA by US, using surgical or clinical information as the reference standard.

Methods

US was performed on 46 neonates aged ≤ 7 days old. In the study group (n = 15), neonates with SBA were confirmed following surgery. In the study group without SBA (n = 15), neonates with other gastrointestinal problems besides SBA were confirmed by surgical or clinical follow-up. Sixteen neonates without gastrointestinal problems were classified as the control group. The colonic diameter was measured, and colonic gas was sought and observed. Statistical analysis was performed to compare US parameters between the study group and other two groups. The optimal cut-off value of the colonic diameter for SBA diagnosis was obtained using receiver operating characteristic analysis.

Results

Colonic diameters (0.5 cm) in the study group (interquartile ranges [IQR], 0.5–0.6 cm) was significantly smaller than that in the group without SBA (0.9 cm; IQR, 0.8–1.2 cm) (P <  0.001) and in the control group (1.2 cm; IQR, 0.8–1.35 cm) (P < 0.001). Optimum cut-off value for diagnosing SBA was 0.65 cm (sensitivity, 90.3%; specificity, 86.7%; accuracy, 89.1%) for the colonic diameter. Combining microcolon and gas-negativity showed the best performance in SBA diagnosis using US, with increased accuracy (91.3%).

Conclusion

A colon < 0.65 cm in diameter should be called a microcolon; combining US with gas-negativity is an essential diagnostic basis for SBA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03629-z.

Emphysematous cystitis as a potential marker of severe Crohn's disease

Background

Emphysematous cystitis (EC) is characterized by the presence of air within the bladder wall, often a complication of urinary tract infection (UTI) by gas-producing organisms. However, EC has also been reported in the setting of infectious colitis suggesting an alternate etiology. We report a rare case of EC in the setting of severe Crohn’s colitis with no clinical evidence of UTI.

Case presentation

A 43-year old female presented with a 2-month history of bloody diarrhea consisting of 8–12 bowel movements a day, weight loss of 10 kg and peripheral edema. She also had multiple ulcerated lesions on her abdominal wall and in the perianal region. Initial CT scan was significant for pancolitis, anasarca and EC. The follow-up CT cystogram, flexible cystoscopy and pelvic MRI confirmed the diagnosis of EC and ruled out any fistulous tracts in the pelvis including enterovesical/colovesical fistula. The patient did not report any urinary symptoms and the urinalysis was within normal limits. An extensive infectious workup was negative. Despite the paucity of infectious findings, the EC was empirically treated with an intravenous third-generation cephalosporin. Colonoscopy was significant for multiple ulcerated and hyperemic areas with pseudopolyps all throughout the right, transverse and left colon. Biopsies confirmed Crohn’s colitis with no evidence of granulomata or dysplasia. Immunohistochemistry was negative for CMV. The perianal and abdominal wall lesions were suspected to be pyoderma gangrenosum although biopsies were equivocal. The colitis was initially treated with intravenous steroids followed by biologic therapy with Infliximab. Despite appropriate escalation of therapies, the patient developed colonic perforation requiring subtotal colectomy.

Conclusion

This is a rare case of EC in a patient with severe Crohn’s colitis. There was no evidence of urinary tract infection or fistulising disease. According to our review, this is the first reported incident of EC in a patient with inflammatory bowel disease without any prior intra-abdominal surgeries. While active Crohn’s disease alone is a critical illness, we conclude that concomitant EC may be a poor prognostic factor.

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.

Multidetector computed tomography: a corner stone imaging modality in evaluation of acute small bowel diseases

Background

The diagnosis of acute small bowel diseases is one of the challenging issues that confronted by the radiologists so accurate diagnosis is essential to determine the appropriate way of management. CT has become the preferred imaging tool to evaluate acute small bowel diseases. Our study aimed to assess the role of MDCT in evaluation of acute abdomen secondary to small bowel origin by identification and differentiation between different acute small bowel pathologies.

Results

Thirty-eight patients presented with acute abdomen of small bowel origin from June 2019 to September 2019. The mean age of incidence was 48 ± 19 years ranged from 4 to 88 years. Males represented by 23 patients (60.5%). Acute exacerbation of inflammatory bowel diseases (Crohn’s disease) represented by (34.2%), small bowel obstruction (31.6%), ischemic bowel diseases (21.1%), small bowel perforation (10.5%) and infectious (TB enteritis) small bowel disease (2.6%). MDCT had an overall high sensitivity (97.3%) in assessment of acute small bowel diseases in correlation with post-operative data and follow-up response to management.

Conclusions

MDCT is a reliable diagnostic imaging tool for assessment of patients with acute abdomen secondary to small bowel origin with high-efficiency in differentiation between different pathological entities that causing acute abdomen.

Challenge in diagnosis of late onset necrotizing enterocolitis in a term infant: a case report

BACKGROUND

Necrotizing enterocolitis (NEC) is a common devastating inflammatory gastrointestinal disease and frequently occurs in premature infants. Here, we reported a case of late-onset NEC in a term neonate with good outcome after surgery for long-term follow-up.

CASE PRESENTATION

Ten-week-old male came to emergency unit due to prolonged diarrhea and abdominal distention. He was born at gestational age of 40 weeks with birth weight and Apgar score of 2800 g and 7/8, respectively. He had no history of formula feeding. Two weeks before admitted to the hospital, the patient had frequent diarrhea with fever. He was found lethargic with abdominal distention, absence of bowel sounds and abdominal tenderness. Plain abdominal x-ray and CT scan showed gastric and intestinal dilatation and gasless colon, suggesting a small bowel obstruction, and bowel wall thickening indicating peritonitis, without any free subdiaphragmatic air (pneumoperitoneum). Moreover, the patient did not have a congenital heart disease. While in intensive medical treatment, he showed a continuous clinical deterioration. All findings were suggestive of intestinal inflammation with clinical deterioration, and we decided to perform an emergency exploratory laparotomy and found an ischemia along the jejunoileal with a perforation at 25 cm above the ileocecal valve. Subsequently, we performed a double-barrel ileostomy through a separate incision from the laparotomy. Histopathological findings confirmed the diagnosis of NEC. We closed the stoma at postoperative day 43. The patient was discharged uneventfully a month after stoma closure.

CONCLUSION

Abdominal CT scan might be useful to establish an early recognition of late-onset NEC; thus, immediate surgical intervention might be performed to decrease its morbidity and mortality. Moreover, late-onset NEC in term neonates might occur without any risk factors or significant co-morbidities.

Sonographic assessment of inflammatory bowel disease in the emergency department: A case series and review of the literature

The use of sonography for diagnosing inflammatory bowel disease (IBD) has been reported in the radiology literature but is not common practice in the hands of emergency physicians (EPs). We present a series of three cases where IBD was managed by an EP using point-of-care ultrasonography (POCUS), and discuss the sonographic features of IBD including bowel wall thickening, increased blood flow on color Doppler, infiltration of surrounding fatty tissue, and presence of intraperitoneal fluid. Complications such as bowel strictures and peri-colic abscess are also described. We suggest that the use of POCUS for the assessment of IBD patients in the ED may expedite both diagnosis and treatment, as well as minimize the use of additional imaging.

Inflammatory bowel disease (IBD) position statement of the Italian Society of Colorectal Surgery (SICCR): general principles of IBD management

The Italian Society of Colorectal Surgery (SICCR) promoted the project reported here, which consists of a Position Statement of Italian colorectal surgeons to address the surgical aspects of inflammatory bowel disease management. Members of the society were invited to express their opinions on several items proposed by the writing committee, based on evidence available in the literature. The results are presented, focusing on relevant points. The present paper is not an alternative to available guidelines; rather, it offers a snapshot of the attitudes of SICCR surgeons about the general principles of surgical treatment of inflammatory bowel disease. The committee was able to identify some points of major disagreement and suggested strategies to improve quality of available data and acceptance of guidelines.

Preliminary Investigation of the Diagnosis of Neonatal Congenital Small Bowel Atresia by Ultrasound

Purpose

To assess the diagnostic value of ultrasonography (US) for congenital small bowel atresia (SBA) in neonates and their sonographic characteristics.

Methods

A retrospective analysis was performed of 20 neonates who were confirmed with SBA by operation from March 2014 to January 2019. All the neonates have been scanned by US before surgery, and no one underwent barium enema or upper gastrointestinal imaging prior to US. Preoperation ultrasound characteristics about intestinal morphology and intestinal contents were collected, further to summarize the typical ultrasonic features of SBA.

Results

Five cases were duodenal atresia, and 15 cases were jejuno-ileal atresia. Distended proximal intestines, liquid with tiny points in it, can be found in 20 neonates. The small intestine without any gas can be found in 20 neonates. Microcolon, no gas and other contents in it, can be found in 16 cases.

Conclusions

The typical ultrasonic features of SBA include dilation in proximal intestines, small intestines, and microcolon. US is a promising modality in the clinical diagnosis of SBA.

Up-to-date overview of imaging techniques in the diagnosis and management of inflammatory bowel diseases

Radiological examination occupies a significant role, complementary to endoscopic studies, in the diagnostic process of inflammatory bowel disease (IBD). Both ulcerative colitis and Crohn’s disease, due to multiple remissions and relapses, require repetitive examinations to evaluate the disease extent, severity, and response to pharmacological treatment. Whereas the use of barium contrast studies is progressively reduced, plain radiography confirms its utility as a first-line imaging tool for acute abdomen. Computed tomography remains an easily accessible and effective method to demonstrate disease activity and extraintestinal manifestations. However, the related radiation exposure reduces its applicability to urgent situations. Ultrasound and magnetic resonance, with the great advantage of avoiding ionising radiation, are highly recommended to present the complications of IBD. Use of oral and intravenous contrast in computed tomography enterography and magnetic resonance enterography demonstrates IBD involvement in the small intestine wall, which is difficult to assess in other radiological and endoscopic examinations.

Inflammatory bowel disease patient perceptions of diagnostic and monitoring tests and procedures

Background

Inflammatory Bowel Disease (IBD) with its high incidence and prevalence rates in Canada generates a heavy burden of tests and procedures. The purpose of this study is to gain a better understanding of the transfer of information from physician to patient, as well as the patient understanding and perceptions about the tests and procedures that are ordered to them in the context of IBD diagnosis and monitoring.

Methods

An online questionnaire was completed by 210 IBD patients in Canada. Information on the five most-often used tests or procedures in IBD diagnosis/monitoring was collected. These include: general blood test, colonoscopy, colon biopsy, medical imaging and stool testing.

Results

The general blood test is both the most ordered and most refused tool. It is also the one with which patients are the least comfortable, the one that generates the least concern and the one about which physicians provide the least information. The stool test is the test/procedure with which patients are the most comfortable. Procedures raise more concerns among patients and physicians provide more information about why they are needed, their impact and the risks they present. Very little information is provided to patients about the risks of having false positives or negative tests.

Conclusions

This study provides an initial understanding of patient perceptions, the transfer of information from a physician to a patient and a patient’s understanding of the tests and procedures that will be required to treat IBD throughout what is a lifelong disease. The present study takes a first step in better understanding the acceptance of the test or procedure by IBD patients, which is essential for them to adhere to the monitoring process.

Electronic supplementary material

The online version of this article (10.1186/s12876-019-0946-8) contains supplementary material, which is available to authorized users.

Application of machine learning algorithms for multiparametric MRI-based evaluation of murine colitis

Magnetic resonance imaging (MRI) allows non-invasive evaluation of inflammatory bowel disease (IBD) by assessing pathologically altered gut. Besides morphological changes, relaxation times and diffusion capacity of involved bowel segments can be obtained by MRI. The aim of this study was to assess the use of multiparametric MRI in the diagnosis of experimentally induced colitis in mice, and evaluate the diagnostic benefit of parameter combinations using machine learning. This study relied on colitis induction by Dextran Sodium Sulfate (DSS) and investigated the colon of mice in vivo as well as ex vivo. Receiver Operating Characteristics were used to calculate sensitivity, specificity, positive- and negative-predictive values (PPV and NPV) of these single values in detecting DSS-treatment as a reference condition. A Model Averaged Neural Network (avNNet) was trained on the multiparametric combination of the measured values, and its predictive capacity was compared to those of the single parameters using exact binomial tests. Within the in vivo subgroup (n = 19), the avNNet featured a sensitivity of 91.3% (95% CI: 86.6–96.0%), specificity of 92.3% (95% CI: 85.1–99.6%), PPV of 96.9% (94.0–99.9%) and NPV of 80.0% (95% CI: 69.9–90.1%), significantly outperforming all single parameters in at least 2 accuracy measures (p < 0.003) and performing significantly worse compared to none of the single values. Within the ex vivo subgroup (n = 30), the avNNet featured a sensitivity of 87.4% (95% CI: 82.6–92.2%), specificity of 82.9% (95% CI: 76.1–89.7%), PPV of 88.9% (84.3–93.5%) and NPV of 80.8% (95% CI: 73.8–87.9%), significantly outperforming all single parameters in at least 2 accuracy measures (p < 0.015), exceeded by none of the single parameters. In experimental mouse colitis, multiparametric MRI and the combination of several single measured values to an avNNet can significantly increase diagnostic accuracy compared to the single parameters alone. This pilot study will provide new avenues for the development of an MR-derived colitis score for optimized diagnosis and surveillance of inflammatory bowel disease.

Small bowel imaging in Crohn's disease patients

Crohn’s disease (CD) is a lifelong, chronic inflammatory bowel disorder. The small bowel (SB) is involved to varying extents, and the clinical course may vary from an inflammatory type to a more complicated one with stricture, fistula, and abscess formation. Esophagogastroduodenoscopy and ileocolonoscopy with biopsies are the conventional endoscopic techniques that usually establish the diagnosis. On the other hand, CD may affect SB segments that cannot be reached through these procedures. Video capsule endoscopy and enteroscopy are additional endoscopic techniques that may allow further SB evaluation in such circumstances. Computed tomographic enterography, magnetic resonance enterography, and ultrasonography are radiologic techniques that serve as a crucial adjunct to endoscopic assessment. They enable the assessment of parts of the bowel that may be difficult to reach with conventional endoscopy; this allows for the detection of active inflammation, penetrating or stricturing disease, and the appreciation of extraintestinal complications. Both endoscopic and radiologic modalities play a role in establishing the diagnosis of CD, as well as determining the disease extent, activity and response to therapy. This review is intended to evaluate these modalities in terms of specificity, sensitivity, potential side-effects, and limiting factors. This should serve as a guide to the clinician for establishing the most appropriate and reliable test within a particular clinical context.

The role of intestinal ultrasound in diagnostics of bowel diseases

Intestinal ultrasound is a safe and inexpensive method that allows visualisation of the gastrointestinal tract and detection of abnormalities. This examination involves the use of two different ultrasound transducers: a low-frequency convex probe and high-frequency linear probe. When needed, the performance of these methods can be enhanced by the use of contrast media or Doppler techniques. Intestinal ultrasound is mostly utilised for the diagnosis and follow-up of patients with inflammatory bowel diseases, helping to avoid frequent use of invasive and expensive diagnostic procedures and leading to early implementation of suitable treatment. This technique can also serve to detect other pathologic conditions that are present in the gastrointestinal tract. It is a promising method with high sensitivity and specificity, which has gained popularity in recent years and has the potential to become the method of choice in the diagnostics of many intestinal disorders.

Anatomical Road Mapping Using CT and MR Enterography for Ultrasound Molecular Imaging of Small Bowel Inflammation in Swine

OBJECTIVES

To evaluate the feasibility and time saving of fusing CT and MR enterography with ultrasound for ultrasound molecular imaging (USMI) of inflammation in an acute small bowel inflammation of swine.

METHODS

Nine swine with ileitis were scanned with either CT (n = 3) or MR (n = 6) enterography. Imaging times to load CT/MR images onto a clinical ultrasound machine, fuse them to ultrasound with an anatomical landmark-based approach, and identify ileitis were compared to the imaging times without anatomical road mapping. Inflammation was then assessed by USMI using dual selectin-targeted (MB_Selectin) and control (MB_Control) contrast agents in diseased and healthy control bowel segments, followed by ex vivo histology.

RESULTS

Cross-sectional image fusion with ultrasound was feasible with an alignment error of 13.9 ± 9.7 mm. Anatomical road mapping significantly reduced (P < 0.001) scanning times by 40%. Localising ileitis was achieved within 1.0 min. Subsequently performed USMI demonstrated significantly (P < 0.001) higher imaging signal using MB_Selectin compared to MB_Control and histology confirmed a significantly higher inflammation score (P = 0.006) and P- and E-selectin expression (P ≤ 0.02) in inflamed vs. healthy bowel.

CONCLUSIONS

Fusion of CT and MR enterography data sets with ultrasound in real time is feasible and allows rapid anatomical localisation of ileitis for subsequent quantification of inflammation using USMI.

KEY POINTS

• Real-time fusion of CT/MRI with ultrasound to localise ileitis is feasible. • Anatomical road mapping using CT/MRI significantly decreases the scanning time for USMI. • USMI allows quantification of inflammation in swine, verified with ex vivo histology.

Light and sound - emerging imaging techniques for inflammatory bowel disease

Patients with inflammatory bowel disease are known to have a high demand of recurrent evaluation for therapy and disease activity. Further, the risk of developing cancer during the disease progression is increasing from year to year. New, mostly non-radiant, quick to perform and quantitative methods are challenging, conventional endoscopy with biopsy as gold standard. Especially, new physical imaging approaches utilizing light and sound waves have facilitated the development of advanced functional and molecular modalities. Besides these advantages they hold the promise to predict personalized therapeutic responses and to spare frequent invasive procedures. Within this article we highlight their potential for initial diagnosis, assessment of disease activity and surveillance of cancer development in established techniques and recent advances such as wide-view full-spectrum endoscopy, chromoendoscopy, autofluorescence endoscopy, endocytoscopy, confocal laser endoscopy, multiphoton endoscopy, molecular imaging endoscopy, B-mode and Doppler ultrasound, contrast-enhanced ultrasound, ultrasound molecular imaging, and elastography.