Role of CT Enterography in Crohn’s Disease Mx

11th August 2024, NIA Diagnostic Imaging

CT enterography (CTE) plays a vital role in the management of Crohn’s disease, a chronic inflammatory bowel disease (IBD). Crohn’s disease is the most common indication for a CTE, primarily used to determine diagnosis and complications (5) to guide effective treatment, and for monitoring disease progression and response to treatment.

WHAT IS CROHN’S DISEASE?

Crohn’s disease is a form of inflammatory bowel disease that can affect the entire gastrointestinal tract. It most commonly involves the small intestine and proximal colon (4), with the ileo-caecal region affected in 50% of cases (7). This condition is marked by chronic, transmural intestinal inflammation (involving the entire thickness of the bowel wall) (4). While the exact cause of Crohn’s disease is unknown, there is considerable evidence suggesting that environmental and immune system factors may contribute to its development (4).

Symptoms of Crohn’s Disease

Patients with Crohn’s disease may initially experience non-specific symptoms like fever and general malaise due to inflammation. The disease can present differently depending on the affected area. Initially, common symptoms include diarrhoea, abdominal pain, nausea, and vomiting (4), with periods of no symptoms lasting from weeks to months. More severe, localised symptoms usually develop after multiple flare-ups (4).

If left untreated, prolonged inflammation can lead to severe complications such as stricture formation and bowel obstruction (4). Early diagnosis and treatments are crucial for improving the quality of life and outcomes for those with Crohn’s disease (4).

WHAT IS CT ENTEROGRAPHY?

Computed tomography enterography (CTE) is a non-invasive imaging technique that has become widely accepted as a principal modality for the assessment of small bowel diseases (1), such as Crohn’s disease. Performing detailed evaluation of the small bowel, it can help identify disease involvement, activity, and extent, along with the presence of complications in patients with Crohn’s disease (2).

Advantages of CT Enterography

Non-invasive imaging technique (1)
High resolution visualisation of the entire thickness of the bowel wall (5)
Simultaneous imaging of other abdominal structures outside of the bowel (5)
Assesses intestinal and extraintestinal pathology to provide greater information about the degree and severity of the disease (1)
Multiplanar images generated by thin section scanning (see Figure 1-3 below)

WHAT TO EXPECT DURING A CT ENTEROGRAPHY?

For this procedure, proper bowel preparation is vital. At our practice, patients must fast from all food and drink for 6 hours prior to the exam (5). Patients are then required to drink approximately 1-1.5L of a neutral or low-density oral contrast over 60-90 minutes to achieve adequate luminal distension of the small bowel (5).

This distension is necessary for better assessment of mucosal enhancement, mural thickness, as well as mesenteric vasculature, which is particularly important in the evaluation of Crohn’s disease (5). It is also required as collapsed bowel loops may mimic pathology. During the CT scan, intravenous contrast is administered, and the scan is obtained during the enteric phase where there is peak mucosal enhancement. This technique aims to optimise bowel wall enhancement and contrast resolution between the mucosa and lumen, thereby improving the detection of small bowel abnormalities and pathology (7).

WHAT IS THE ROLE OF CT ENTEROGRAPHY IN MANAGEMENT OF CROHN’S DISEASE?

Diagnosis and assessment of disease extent

CT enterography (CTE) is a highly accurate method for diagnosing and evaluating Crohn’s disease in adults (6). It is particularly useful to assess the severity, extent and location of the disease in the small intestine, which can be challenging with other imaging modalities. This scan can also evaluate any extraluminal manifestations and complications such as strictures, fistulas and abscesses, which is crucial for guiding timely and effective treatment (6).

Treatment decision making

Before commencing medical treatment or preoperative surgical planning, it is important to use CTE to confirm the presence of the disease, determine its severity and evaluate any complications (2). The detailed imaging provided by CTE is valuable by helping distinguish between active and fibrotic bowel strictures in patients with Crohn’s disease, thereby guiding

appropriate treatment decisions which may include medical therapy, surgical resection or endoscopic interventions (3).

Monitoring disease progression and response to treatment

Due to the chronic and relapsing nature of Crohn’s disease, follow up CTE scans are utilised to monitor the disease progression and response to therapeutic strategies (2). By assessing treatment efficacy, appropriate adjustments can be made as needed to the treatment plan (7).

CASE STUDY

A 71-year-old female patient presented to our clinic with a history of Crohn’s disease and increased right sided pain. A CT enterography revealed thickening of the small bowel wall in the ileum, extending over 20 cm to the ileo-caecal junction (see Figure 4). There was also fat stranding in the surrounding area, suggesting possible infectious or an inflammatory bowel condition. Specialist opinion was recommended.

Follow Up Scan

The referring doctor then requested a reassessment of activity following increased therapy. A follow-up CT enterography was performed with multislice sections acquired following oral and intravenous contrast (see Figure 5). Compared to the previous CT study performed four months prior, the results show significant improvements, with less fat stranding and less thickening of the ileum although some inflammatory changes persist.

CONCLUSION

Overall, CTE is a valuable tool in the comprehensive management of Crohn’s disease, aiding in diagnosis, monitoring, and treatment planning.

At NIA Diagnostic Imaging, our highly trained staff members and on-site radiologists aim to ensure that all patients have a seamless experience. Please contact us for any further information:

NIA Glenquarie Radiology
- (02) 9158 8660
- info@niaimaging.com.au
NIA Ingleburn Radiology
- (02) 8104 0803
- info.ingleburn@niaimaging.com.au

REFERENCES

Ali, R. M. M., & Ghonimy, M. B. I. (2021). Diagnostic role of computed tomography enterography (CTE) in assessment of intra-mural and extra-intestinal CT findings in active Crohn’s disease (CD). Egyptian Journal of Radiology and Nuclear Medicine, 52(124). https://doi.org/10.1186/s43055-021-00506-0
Guglielmo, F. F., Anupindi, S. A., Fletcher, J. G., Al-Hawary, M. M., Dillman, J. R., Grand, D. J., Bruining, D. H., Chatterji, M., Darge, K., Fidler, J. L., Gandhi, N. S., Gee, M. S., Grajo, J. R., Huang, C., Jaffe, T. A., Park, S. H., Rimola, J., Soto, J. A., Taouli, B., Taylor, S. A., … Baker, M. E. (2020). Small bowel Crohn disease at CT and MR enterography: Imaging atlas and glossary of terms. Radiographics, 40(2), 354–375. https://doi.org/10.1148/rg.2020190091
Ismail, M. S., & Charabaty, A. (2022). Management of Crohn’s stricture: medical, endoscopic and surgical therapies. Frontline Gastroenterology, 13. 524–530.
Ranasinghe, I. R., Tian, C., & Hsu, R. (2024). Crohn disease. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK436021
Ibrahim, D., Ranchod, A., & Murphy, A. (2023). CT enterography (protocol). Radiopaedia.org. Retrieved June 4, 2024, from https://doi.org/10.53347/rID-30358
Saade, C., Nasr, L., Sharara, A., Barada, K., Soweid, A., Murad, F., Tawil, A., Ghieh, D., Asmar, K., Tamim, H., & Khoury, N. J. (2019). Crohn’s disease: A retrospective analysis between computed tomography enterography, colonoscopy, and histopathology. Radiography (London), 25(4), 349–358. https://doi.org/10.1016/j.radi.2019.04.007
Park, M. J., & Lim, J. S. (2013). Computed tomography enterography for evaluation of inflammatory bowel disease. Clinical Endoscopy, 46(4), 327–366. https://doi.org/10.5946/ce.2013.46.4.327

PFO Closure

Furlan AJ, Reisman M, Massaro J, et al. Closure or medical therapy for cryptogenic stroke with patent foramen ovale. N Engl J Med 2012; 366: 991–

A multicenter, randomized, open-label trial of closure with a percutaneous device, as compared with medical therapy alone, in patients between 18 and 60 years of age who presented with a cryptogenic stroke or transient ischemic attack (TIA) and had a patent foramen ovale. The primary end point was a composite of stroke or transient ischemic attack during 2 years of follow-up, death from any cause during the first 30 days, or death from neurologic causes between 31 days and 2 years.

Results:

Primary end point was 5.5% in the closure group as compared with 6.8% in the medical-therapy group (adjusted hazard ratio, 0.78; 95% confidence interval, 0.45 to 1.35; P = 0.37)

Conclusion:

“In patients with cryptogenic stroke or TIA who had a patent foramen ovale, closure

with a device did not offer a greater benefit than medical therapy alone for the

prevention of recurrent stroke or TIA”

2 Saver JL, Carroll JD, Thaler DE, et al. Long-term outcomes of patent foramen ovale closure or medical therapy after stroke. N Engl J Med 2017; 377: 1022–

A multicenter, randomised, open-label trial ,randomly assigned patients 18 to 60 years of age who had a patent foramen ovale (PFO) and had had a cryptogenic ischemic stroke to undergo closure of the PFO (PFO closure group) or to receive medical therapy alone (aspirin, warfarin, clopidogrel, or aspirin combined with extended-release dipyridamole; medical-therapy group). The primary efficacy end point was a composite of recurrent nonfatal ischemic stroke, fatal ischemic stroke, or early death after randomisation.

Results:

Recurrent ischemic stroke occurred in 18 patients in the PFO closure group and in 28 patients in the medical-therapy group, resulting in rates of 0.58 events per 100 patient-years and 1.07 events per 100 patient years, respectively (hazard ratio 0.55; 0.31 – 0.999; P = 0.046)

Conclusion:

“Among adults who had had a cryptogenic ischemic stroke, closure of a PFO was associated with a lower rate of recurrent ischemic strokes than medical therapy alone during extended follow-up.”

Meier B, Kalesan B, Mattle HP, et al. Percutaneous closure of patent foramen ovale in cryptogenic embolism. N Engl J Med 2013; 368: 1083–

A prospective, multicenter, randomised, event-driven trial, randomly assigned patients to medical therapy alone (anti-platelet or warfarin therapy) or closure of the patent foramen ovale.

Results:

9 patients in the closure group and 16 in the medical-therapy group had a recurrence of stroke (hazard ratio with closure, 0.49; 0.22 – 1.11; P = 0.08). The primary analysis of the intentionto- treat cohort showed a nominal 51% hazard rate reduction with closure, but the reduction did not reach significance.

Conclusions:

” …there was no significant benefit associated with closure of a patent foramen ovale in adults who had had a cryptogenic ischaemic stroke.”

Sondergaard L, Kasner SE, Rhodes JF, et al. Patent foramen ovale closure or antiplatelet therapy for cryptogenic stroke. N Engl J Med 2017; 377: 1033–

Multinational trial involving patients with a PFO who had had a cryptogenic stroke, randomly assigned patients to undergo PFO closure plus antiplatelet therapy or to receive antiplatelet therapy alone.

Results:

During a median follow-up of 3.2 years, clinical ischemic stroke occurred in 6 of 441 patients (1.4%) in the PFO closure group and in 12 of 223 patients (5.4%) in the antiplatelet-only group (hazard ratio, 0.23; 0.09 to 0.62; P=0.002).

Conclusions:

“Among patients with a PFO who had had a cryptogenic stroke, the risk of subsequent ischemic stroke was lower among those assigned to PFO closure combined with antiplatelet therapy than among those assigned to antiplatelet therapy alone; however, PFO closure was associated with higher rates of device complications and atrial fibrillation.”

Mas JL, Derumeaux G, Guillon B, et al. Patent foramen ovale closure or anticoagulation vs. antiplatelets after stroke. N Engl J Med 2017; 377: 1011–

In a multicenter, randomised, open-label trial patients 16-60 years of age who had had a recent stroke attributed to PFO, to transcatheter PFO closure plus long-term antiplatelet therapy, antiplatelet therapy alone or oral anticoagulation.

Results:

No stroke occurred among patients in the PFO closure group, whereas stroke occurred in 14 of the 235 patients in the antiplatelet- only group (hazard ratio, 0.03; 0 to 0.26; P<0.001). Large number of patients discontinued anti-coagulation in the anti-coagulant group and statistical significance was not analysed because the study was not adequately powered to compare outcomes.

Conclusion:

“Among patients who had had a recent cryptogenic stroke attributed to PFO with an associated atrial septal aneurysm or large interatrial shunt, the rate of stroke recurrence was lower among those assigned to PFO closure combined with antiplatelet therapy than among those assigned to antiplatelet therapy alone. PFO closure was associated with an increased risk of atrial fibrillation.”

Lee PH, Song J-K, Kim JS, et al. Cryptogenic stroke and high-risk patent foramen ovale: the DEFENSE-PFO Trial. J Am Coll Cardiol 2018; 71: 2335–

Patients with cryptogenic stroke and high-risk PFO were divided between a transcatheter PFO closure and a medication-only group.

Results:

No events occurred in the PFO closure group. 12.9% of patients in the medication group had an event (p= 0.023).

Conclusion:

“PFO closure in patients with high-risk PFO characteristics resulted in a lower rate of the primary endpoint as well as stroke recurrence”