Objectives

To describe the typical features of perianal fistulas in Magnetic Resonance Imaging (MRI) according to their classification;

To review the importance of accurate MRI protocol in perianal fistulas diagnosis.

Background

Perianal fistula is an uncommon inflammatory condition with significant morbidity in the affected population defined as an abnormal communication between the anal canal and the perianal skin or perineum. In patients with Crohn’s disease it is a major problem and affects significantly their quality of life. An appropriate knowledge of the anatomy of the anal sphincter complex and its surrounding structures is crucial for a correct image interpretation. MRI is the method of choice to evaluate perianal fistulas as it provides the visualization of fistula’s relationship with adjacent structure and clarifies the extension of the disease.

Imaging findings OR Procedure findings

Several clinical cases were selected in order to illustrate the typical imaging findings of perianal fistulas according to the St Jame’s University Hospital classification. This classification contemplates important MRI findings and grades the perianal fistulas in five different groups. The primary fistulous track and the presence of abscesses or secondary extensions are the demanding criteria which outline the best treatment decision.

Sequences as T2-weighted with fat-suppression are crucial to recognize fistulous tracts and fluid collections. T1-weighted contrast-enhanced fat-suppressed sequences are important to detecte active fistulas and granulation tissue.

Conclusion

MRI is the gold standard imaging technique to study perianal fistulas once allows the detection of lesions that can be deeply hidden. A structured MRI report is essential for therapeutic management and consequently improves of patient outcome.

Objectives

The purpose of this study is to review the diagnostic and staging features of pancreatic cancer and summarize the importance of Radiology to evaluate resectability criteria according to the National Comprehensive Cancer Network (NCCN), essential to establish the patient’s approach.

Background

Pancreatic adenocarcinoma (PA) represents 80% of pancreatic cancer, and it is one of the most fatal solid tumors. Computed tomography (CT) is the gold-standard imaging strategy for diagnosis and staging of PA, although it has some limitations, such as detection of minor tumors, local lymphatic involvement and small peritoneal and hepatic metastization. Nowadays, the most useful classification for PA staging is the NCCN, that is based on TNM system. The NCCN classification divides pancreatic tumors in ressecable, non-ressecable and borderline groups, taking in consideration some imagiological features. The ressectabilty of a PA is the most important independent prognostic factor for survival of these patients, because total resection surgery is the only treatment with curative potential.

Imaging findings OR Procedure findings

The initial imaging approach should include location and tumoral size, vascular involvement, perineural and lymphatic invasion, tumoral density, duodenal invasion and metastization. These features have surgical implications. Bigger and local advanced lesions are associated with poorer outcome. One of the most important criteria for ressectabilty is vascular involvement, and when present is generally associated with positive surgical margins.

Conclusion

Pre-operative imaging evaluation for ressectability is crucial to assist on the most effective and individualized therapeutic strategy for patients with PA.