MR Enterography: Crohn’s Disease and Beyond

Description

This second edition is primarily dedicated to MR-Enterography, an imaging modality whose reliability for intestinal assessment in patients suffering from inflammatory bowel diseases has gained increasing consensus. The performance of this technique has been significantly enlarged over the last years, due to its undoubted advantages in terms of exhaustive evaluation of the abdominal cavity and safeness due to the lack of radiation exposure.  The first part is focused on MR-Enterography standard protocol. Nevertheless, additional sequences, technical novelties and common pitfalls are reported and discussed.   In the second section, the typical intestinal and extra-intestinal findings related to Crohn’s disease are described in detail. In this edition, more emphasis has been put on practical topics, useful in the daily clinical practice: anatomical changes after surgical procedures, structured reporting and emerging clinical applications over inflammatory bowel diseases. Another part is dedicated to Magnetic Resonance Imaging of the anal canal, including technical aspects and clinical implications. The text is largely complemented by diagnostic images. Nonetheless, at the end of the book 30 illustrated cases show different clinical scenarios evaluated with MR-Enterography and Magnetic Resonance Imaging of the anal canal. Contents Contributors 1: Introduction References 2: Small Bowel Imaging Other Than MR-Enterography 2.1 X-Ray and Fluoroscopy 2.2 Ultrasound 2.3 Computed Tomography References 3: MR-Enterography: Technique 3.1 Enteric Contrast Agents 3.2 Patient’s Preparation and Positioning 3.3 Protocols and Sequences 3.3.1 T2-Weighted Scans 3.3.1.1 Half-Fourier Single-Shot Turbo Spin Echo (HASTE) 3.3.1.2 Single-Shot Thick-Slab RARE 3.3.2 Balanced Steady-State Free Precession (Balanced SSFP) 3.3.3 Pre- and Post-Contrast T1-Weighted 3.3.3.1 Ultrafast Gradient Echo 3.4 Spasmolytics 3.5 Intravenous Contrast Agent 3.6 Complementary MR Techniques 3.6.1 MR Fluoroscopy 3.6.2 Cine MR 3.6.3 Diffusion-Weighted Imaging 3.7 Technical Novelties and Future Perspectives References 4: MR Enterography: Anatomy 4.1 Normal MR Anatomy of Duodenum and Small Bowel 4.2 Normal MR Anatomy of Sphincters and Perianal Region 4.3 Anatomical Changes after Surgery: Types of Interventions and Anastomoses 4.3.1 Small and Large Bowel 4.3.2 Anal Canal References 5: MR-Enterography Intestinal Findings in Crohn’s Disease 5.1 Wall Thickening 5.2 Ulcerations 5.3 Increased Vascularity 5.4 Patterns of Wall Enhancement 5.5 Perienteric Inflammation 5.6 Reactive Lymph Nodes 5.7 Mesenteric Fibrofatty Proliferation 5.8 Penetrating and Stricturing Patterns in CD 5.8.1 Penetrating Disease 5.8.2 Fibrostenosing Disease References 6: Extraintestinal Complications in Crohn’s Disease: MR-Enterography Findings 6.1 Hepatobiliary Complications 6.1.1 Primary Sclerosing Cholangitis 6.1.2 Gallstone Disease 6.1.3 Liver Abscess 6.1.4 Portal Vein Thrombosis 6.2 Pancreatic Complications 6.3 Genitourinary Complications 6.3.1 Ureteral Obstruction 6.3.2 Nephrolithiasis 6.3.3 Genitourinary Tract Fistulas 6.4 Musculoskeletal and Cutaneous Manifestations 6.5 Peritoneal Involvement References 7: MR-Enterography beyond Crohn’s Disease 7.1 Congenital Anomalies, Anatomical Variants, and Paraphysiological Findings 7.2 Acquired Nonneoplastic Intestinal Conditions 7.2.1 Motility Disorders 7.2.2 Ulcerative Colitis 7.2.3 Appendicitis 7.2.4 Celiac Disease 7.2.5 Infections 7.2.6 Eosinophilic Gastroenteritis 7.2.7 Systemic Sclerosis 7.2.8 Amyloidosis 7.2.9 Noninfective Vasculitis 7.3 Neoplastic Lesions 7.3.1 Benign Neoplastic Lesions 7.3.1.1 Polyps 7.3.1.2 Adenomas 7.3.1.3 Leiomyomas 7.3.1.4 Lipomas 7.3.2 Malignant Neoplastic Lesions 7.3.2.1 Gastrointestinal Stromal Tumors 7.3.2.2 Adenocarcinoma 7.3.2.3 Neuroendocrine Tumors 7.3.2.4 Lymphoma References 8: MR-Enterography Pitfalls 8.1 Sequences-Related Pitfalls 8.1.1 Half-Fourier Acquisition Single-Shot Turbo Spin Echo Imaging (HASTE) 8.1.2 Fast Imaging with Steady-State Free Precession 8.1.3 Diffusion Weighted Imaging 8.1.4 Ge T1-W FS Pre- and Post-Contrast Medium Injection 8.2 Intestinal Filling 8.3 Peristaltic Spasms References 9: MRI of the Anal Region in Crohn’s Disease and Beyond 9.1 Classification of Fistulas 9.2 Technique 9.3 Perianal Findings in Crohn’s Disease 9.4 MRI of the Anal Canal beyond Crohn’s Disease 9.4.1 Inflammatory Conditions 9.4.1.1 Pilonidal Sinus 9.4.1.2 Hidradenitis Suppurativa 9.4.1.3 Fournier Gangrene 9.4.2 Benign Lesions 9.4.3 Malignant Neoplasms References 10: Structured Reporting 10.1 MR-Enterography 10.2 Perianal MRI References 11: Clinical Cases 11.1 MR-Enterography Clinical Cases (Figs. 11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 11.10, 11.11, 11.12, 11.13, 11.14, 11.15, 11.16, 11.17, 11.18, 11.19, 11.20, 11.21, 11.22 and 11.23) 11.2 MRI Perianal Involvement Cases (Figs. 11.24, 11.25, 11.26, 11.27, 11.28, 11.29 and 11.30)