Frequency and nature of incidental extra-enteric lesions found on magnetic resonance enterography (MR-E) in patients with inflammatory bowel diseases (IBD)

Abdominal Pain in Inflammatory Bowel Disease: An Evidence-Based, Multidisciplinary Review

Abdominal pain is one of the most common and impactful symptoms associated with inflammatory bowel disease (IBD), including both Crohn's disease and ulcerative colitis. A great deal of research has been undertaken over the past several years to improve our understanding and to optimize management of this issue. Unfortunately, there is still significant confusion about the underlying pathophysiology of abdominal pain in these conditions and the evidence underlying treatment options in this context. There is also a relative paucity of comprehensive reviews on this topic, including those that simultaneously evaluate pharmacological and nonpharmacological therapeutic options. In this review, our multidisciplinary team examines evidence for various currently available medical, surgical, and other analgesic options to manage abdominal pain in IBD.

Frequency and significance of incidental liver lesions on MR enterography in adult patients

PURPOSE

To evaluate the frequency and significance of incidental liver lesions identified on MR enterography (MRE) examinations to determine if dedicated sequences for liver evaluation are necessary in the routine MRE protocol.

METHODS

A retrospective departmental database search identified 353 adult (212 women and 141 men; mean [±SD] age, 41.4 [17.0] years; range 18.1-91.9 years) MRE examinations performed in 2017. Radiology reports were reviewed for the presence and characterization of liver lesions, follow-up recommendation, and known malignancy. Follow-up cross-sectional imaging reports were reviewed for liver lesion stability. A senior abdominal radiologist with expertise in liver imaging categorized liver lesions as benign, indeterminate, or malignant and re-characterized indeterminate lesions using follow-up imaging as benign or malignant.

RESULTS

Seventy-nine MRE (22.4%) described liver lesions and follow-up imaging was recommended in 4/79 (5.1%). Seventy-six liver lesions (96.2%) were characterized as benign (cysts/hemangiomas) on routine interpretation and expert review. One of these was recommended for follow-up imaging on initial report, which was characterized as hemangioma by expert review. The remaining 3 lesions (3.8%) were characterized as indeterminate both by initial report and expert radiologist review but re-characterized as benign after reviewing follow-up examinations.

CONCLUSION

All incidental liver lesions identified on MRE in our cohort were benign. Therefore, additional sequences evaluating the liver are unnecessary for routine MRE.

Prevalence and clinical significance of incidental extra-intestinal findings in MR enterography: experience of a single University Centre

PURPOSE

To determine the incidence and clinical relevance of extra-intestinal incidental findings (IF) in a cohort of patients with proven or suspected Crohn disease (CD) examined with magnetic resonance enterography (MR-E) in a single University Centre.

METHODS

Between January 2018 and June 2019, 182 patients with proven or suspected CD with a planned first MR-E examination, were retrospectively included in this study. Incidental findings were considered as any abnormality identified in the absence of previous clinically suspected or known disease. IF were categorized as unremarkable, benign or potentially relevant findings requiring further imaging or specific treatment.

RESULTS

Of the 182 revised MR-E, extra-intestinal IF were recorded in 70 cases (38.5%); 35 (50%) incidental lesions were recognized as non-significant, 24 (34%) as benign and 11 (16%) as clinically relevant. Moreover, there was a positive correlation between IF and patients' age (p < 0.0001).

CONCLUSIONS

In our experience, a high number of IF (38.5%) was found, with a prevalence that increases with patients' age. Clinically relevant findings were found in 16% of MR-E. This means that MR-E is a useful tool to detect IF, therefore, the presence of a radiologist during the image acquisition is crucial in adding sequences to the examination.

Unexpected Findings in Magnetic Resonance Enterography and Their Clinical Significance

Aims. To identify the prevalence of colonic and extraenteric incidental findings in magnetic resonance enterography (MRE) and their clinical significance. Methods. We retrospectively analysed 470 MRE studies carried out between March 2012 and 2014. Incidental findings were defined as those not expected from or made apparent on the referral. MRE reports were reviewed for colonic and extraenteric findings, subcategorised into "clinically significant" and "insignificant." Follow-up was identified from the electronic patient record. Results. The majority of MRE requests were made for inflammatory bowel disease (97%). In total, 114 incidental findings were noted in 94 (20%) scans performed. There were 29 "colonic" findings (25%) with 55% having a diagnosis of colitis. Out of 85 extraenteric findings, ovarian cysts (25%), renal cysts (10%), and abdominal lymphadenopathy (9%) were the commonest. Cumulatively, 59 cases were clinically significant (52%); of these, 30 findings were not previously diagnosed, amounting to 26% of all incidental findings. This led to intervention in seven patients. Conclusions. Incidental findings are common in MRE and there is a substantial proportion that is clinically significant and requires further investigation. There need to be stratification of risk and employment of local guidelines in order to achieve this.

Magnetic resonance enterography: a pictorial review of Crohn's disease

Use of magnetic resonance enterography has significantly increased and its role as an adjunct to ileocolonoscopy is best practice, particularly in the evaluation of Crohn's disease. This article reviews magnetic resonance enterography, and describes common findings related to Crohn's disease and unexpected extra-intestinal findings.

Monitoring disease activity and progression in Crohn's disease. A Swiss perspective on the IBD ahead 'optimised monitoring' recommendations

BACKGROUND AND AIMS

The structured IBD Ahead 'Optimised Monitoring' programme was designed to obtain the opinion, insight and advice of gastroenterologists on optimising the monitoring of Crohn's disease activity in four settings: (1) assessment at diagnosis, (2) monitoring in symptomatic patients, (3) monitoring in asymptomatic patients, and (4) the postoperative follow-up. For each of these settings, four monitoring methods were discussed: (a) symptom assessment, (b) endoscopy, (c) laboratory markers, and (d) imaging. Based on literature search and expert opinion compiled during an international consensus meeting, recommendations were given to answer the question 'which diagnostic method, when, and how often'. The International IBD Ahead Expert Panel advised to tailor this guidance to the healthcare system and the special prerequisites of each country. The IBD Ahead Swiss National Steering Committee proposes best-practice recommendations adapted for Switzerland.

METHODS

The IBD Ahead Steering Committee identified key questions and provided the Swiss Expert Panel with a structured literature research. The expert panel agreed on a set of statements. During an international expert meeting the consolidated outcome of the national meetings was merged into final statements agreed by the participating International and National Steering Committee members - the IBD Ahead 'Optimized Monitoring' Consensus.

RESULTS

A systematic assessment of symptoms, endoscopy findings, and laboratory markers with special emphasis on faecal calprotectin is deemed necessary even in symptom-free patients. The choice of recommended imaging methods is adapted to the specific situation in Switzerland and highlights the importance of ultrasonography and magnetic resonance imaging besides endoscopy.

CONCLUSION

The recommendations stress the importance of monitoring disease activity on a regular basis and by objective parameters, such as faecal calprotectin and endoscopy with detailed documentation of findings. Physicians should not rely on symptoms only and adapt the monitoring schedule and choice of options to individual situations.

Incidence and evaluation of incidental abnormal bone marrow signal on magnetic resonance imaging

Purpose. The increased use of magnetic resonance imaging (MRI) has resulted in reports of incidental abnormal bone marrow (BM) signal. Our goal was to determine the evaluation of an incidental abnormal BM signal on MRI and the prevalence of a subsequent oncologic diagnosis. Methods. We conducted a retrospective cohort study of patients over age 18 undergoing MRI between May 2005 and October 2010 at Tufts Medical Center (TMC) with follow-up through November 2013. The electronic medical record was queried to determine imaging site, reason for scan, evaluation following radiology report, and final diagnosis. Results. 49,678 MRIs were done with 110 patients meeting inclusion criteria. Twenty two percent underwent some evaluation, most commonly a complete blood count, serum protein electrophoresis, or bone scan. With median follow-up of 41 months, 6% of patients were diagnosed with malignancies including multiple myeloma, non-Hodgkins lymphoma, metastatic non-small cell lung cancer, and metastatic adenocarcinoma. One patient who had not undergone evaluation developed breast cancer 24 months after the MRI. Conclusions. Incidentally noted abnormal or heterogeneous bone marrow signal on MRI was not inconsequential and should prompt further evaluation.

Imaging of the small bowel: Crohn’s disease in paediatric patients

In more than 20% of all patients, the Crohn’s disease presents before the age of 18years. The diagnosis and management of Crohn’s disease in children has changed dramatically over the last decade, mainly due to increased awareness, availability of newer diagnostic modalities such as magnetic resonance imaging (MRI) and newer, more powerful treatments such as biologics. Imaging of the small bowel is needed for diagnosis, management, follow-up and also evaluation of the disease in terms of location, extent, activity and complications. We review all the methods (barium examinations, ultrasonography, computed tomography, MR, and computed tomography- positron emission tomography) commonly used for imaging the small bowel in paediatric patients with Crohn’s disease analyzing the advantages and disadvantages of each modality, with particular emphasis on MR imaging.

Update imaging in inflammatory bowel diseases

Imaging is a central component of the diagnostic process in inflammatory bowel diseases. This review summarizes the recent progress of various most commonly used imaging modalities including computed tomography enterography, magnetic resonance enterography and capsule endoscopy. Advantages and disadvantages of each imaging protocol in suspected and established inflammatory bowel diseases are reviewed and brought into context in proposed diagnostic algorithms.

Small bowel imaging with MRI

Magnetic resonance imaging (MRI) has evolved as a powerful tool for the assessment of the small bowel. Strengths of MRI include the superb soft-tissue contrast, lack of radiation exposure, and the implementation of fast scanning techniques. Clinically relevant findings such as inflammation and tumor disease can be well-depicted. We describe in this article current techniques of small bowel MRI including its implementation and clinical outcome in comparison to other radiological and endoscopic procedures.

MRI enterography: what is the clinical impact of unsuspected extra-enteric findings?

To define the incidence and nature of incidental extra-enteric findings on magnetic resonance enterography (MRE) following the introduction of a new clinical service, to assess the volume of additional tests generated and to gauge the potential of MRE to reduce the need for subsequent abdominal imaging. The imaging and patient records of 500 consecutive patients undergoing MRE at a single institution were reviewed. Note was made of patient demographics, any extra-enteric findings reported on the MRE, whether additional tests were recommended by the reporting radiologists to clarify or follow up extra-enteric findings and whether the patients underwent additional abdominal or pelvic imaging in the 4 months after the MRE. 64% of the cohort was male. The mean age was 45 years (range 11-80 years). Overall 190 (38%) underwent MRE for assessment of known Crohn's disease and 310 (62%) for other indications, such as abdominal pain and anaemia. 26 non-bowel-related extra-enteric abnormalities were noted on the MRE report in just 15 patients (3%), and a total of 6 additional tests were recommended by the reporting radiologist. 13 patients (2.6%) underwent some form of abdominal imaging within 4 months of the MRE. None of these additional investigations revealed any abnormality missed on the MRE. Extra-enteric findings are unlikely to have a significant impact on healthcare resources after the introduction of an MRE service.

Pre-uterine artery embolization MRI: beyond fibroids

Uterine leiomyomata, or fibroids, although benign, cause debilitating symptoms in many women. Symptoms are often nonspecific and may be the presenting complaint in a number of other conditions. Furthermore, because the presence of fibroids may be coincident with other symptomatic conditions that result in similar complaints, there may be diagnostic difficulty and consequent difficulty in planning therapeutic strategy. Uterine artery embolization (UAE) is a safe and effective treatment for symptomatic fibroids and is increasingly being performed. Magnetic resonance imaging (MRI) evaluation before and after treatment is routine practice with the potential to significantly alter management in up to a fifth of patients. It is well recognized that significant incidental findings may be demonstrated during imaging investigations, and in particular that abnormalities that are not directly related to the clinical question may be overlooked. Radiologists evaluating pre-UAE MRI studies must be aware of the MRI appearances of gynecological pathologies that may cause similar symptoms or that may affect the success or complication rates of UAE, and they must also be wary of "satisfaction of search," reviewing imaging thoroughly so that relevant other pathologies are not missed. We demonstrate the appearances of coincidental pathologies found on pre-UAE MRI, with the potential to change patient management.

MR colonography and MR enterography

The bowel is a common site for pathologic processes, including malignancies and inflammatory disease. Colorectal cancer accounts for 10% of all new cancers and 9% of cancer deaths. A significant decrease in the incidence of colorectal cancer and cancer death rates has been attributed to screening measures, earlier detection, and improved therapies. Virtual colonoscopy (VC), also known as computed tomography colonography, is an effective method for detecting polyps. However, in light of increasing concerns about ionizing radiation exposure from medical imaging and potential increased risk of future radiation-induced malignancies, magnetic resonance imaging (MRI) is seen as an increasingly attractive alternative. Improvements in MRI technology now permit three-dimensional volumetric imaging of the entire colon in a single breath hold at high spatial resolution, making VC with MRI possible.

Comparison of conventional abdominal CT with MR-enterography in patients with active Crohn's disease and acute abdominal pain

RATIONALE AND OBJECTIVES

Patients with known Crohn's disease (CD) and an acute onset of severe abdominal pain attending an emergency room frequently undergo contrast-enhanced emergency computed tomography (CT) for complication assessment. To assess small bowel changes, an additional dedicated imaging procedure such as magnetic resonance enterography (MRE) is regularly performed. Therefore, these patients undergo two imaging procedures, although the clinical and diagnostic value of such an approach is not known. In a retrospective study, we compared the diagnostic value of a conventional abdominal CT with a dedicated small bowel MRE to assess bowel wall changes as well as typical complications in patients with advanced CD.

MATERIALS AND METHODS

We retrospectively evaluated 53 patients with CD having a conventional abdominal multidetector-CT (MD-CT) and MRE within 2 days. Image quality and bowel inflammation was analyzed for each bowel segment. Lymph nodes, abscesses, and fistulas were evaluated.

RESULTS

For small bowel and colon assessment, there was no significant difference for image quality between CT and MRE. Inflammation diagnosis was not significantly different between CT (69.4%) and MRE (71.4%). Colonic inflammation was diagnosed in 30.2% based on CT and 14.3% based on MRE. The difference for the detection of lymph nodes was significant (CT 49; MRE 27), whereas the differences between fistula (CT 25, MRE 27) or abscesses (CT and MRE 32) detection were not significant.

CONCLUSIONS

In patients with known advanced CD with acute abdominal pain conventional abdominal MD-CT, which is frequently performed as an emergency imaging procedure, is sufficient for bowel wall assessment. Based on our data, additional dedicated small bowel imaging such as MRE seems not to be necessary.

Incidental findings at MRI-enterography in patients with suspected or known Crohn’s disease

AIM: To determine the frequency and clinical impact of incidental findings detected with magnetic resonance imaging (MRI)-enterography in patients with suspected or known Crohn’s disease (CD).

METHODS: Incidental findings were defined as unexpected lesions outside the small intestine, not previously known or suspected at the time of referral, and not related to inflammatory bowel disease. Through a systematic review of medical charts we analyzed the clinical impact of incidental findings, and compared the MRI findings with subsequent diagnostic procedures.

RESULTS: A total of 283 patients were included in the analysis, and MRI detected active CD in 31%, fistula in 1.4% and abscess in 0.7%. Extra-intestinal findings not related to CD were recorded in 72 patients (25%), of which 58 patients (20%) had 74 previously unknown lesions. Important or incompletely characterized findings were detected in 17 patients (6.0%). Incidental findings led to 12 further interventions in 9 patients (3.2%) revealing previously unknown pathological conditions in 5 (1.8%). One patient (0.4%) underwent surgery and one patient was diagnosed with a malignant disease. MRI detected incidental colonic lesions in 16 patients of which additional work-up in 4 revealed normal anatomy. Two patients (0.7%) benefitted from the additional examinations, whereas incidental findings led to unnecessary examinations in 9 (3.2%).

CONCLUSION: In a minority of patients with suspected or known CD, important incidental findings are diagnosed at MRI-enterography. However, a substantial number of patients experience unnecessary morbidity because of additional examinations of benign or normal conditions.