Diagnostic Ultrasound - Abdomen and Pelvis
Share Embed Flag
Download ePaper

Diagnostic Ultrasound - Abdomen and Pelvis

powerstage
09.07.2019 Views

Crohn Disease TERMINOLOGY Synonyms • Terminal ileitis, regional enteritis, ileocolitis Definitions • Chronic, relapsing granulomatous inflammatory disease with predominant involvement of gastrointestinal tract IMAGING General Features • Best diagnostic clue ○ Bowel wall thickening – Adults: > 3 mm – Children: Small bowel thickness > 2.5 mm and large bowel wall thickness > 2 mm • Location ○ From mouth to anus – Involvement: Terminal ileum (95%), colon (22-55%), rectum (14-50%) □ Small bowel alone (30-35%), small bowel and colon (50-60%), colon alone (20%) – Increased small bowel involvement in younger patients (80% vs. 60%) ○ Look for skip lesions: Normal bowel between areas of involved bowel Ultrasonographic Findings • Grayscale ultrasound ○ Mural – Bowel wall thickening – Increased or decreased echogenicity of bowel wall – Loss of normal bowel wall stratification – Ulceration – Fistula/sinus tract – Intramural abscess – Luminal narrowing – Postinflammatory polyps can form during healing of extensive ulcerative disease ○ Extramural – Thickening/increased echogenicity of mesentery – Separation of bowel loops – Fistulas (enteroenteric, enteromesenteric, enterocutaneous, enterovesical, enterovaginal) – Lymphadenopathy – Phlegmon/abscess ○ Decreased/absent peristalsis of involved bowel • Color Doppler ○ Hyperemia of bowel wall and mesentery – Correlates with disease activity as angiogenesis and inflammation are directly correlated • Contrast material-enhanced ultrasonography ○ Improves sensitivity for detecting inflammation ○ Objective quantification for assessing degree of inflammation and for follow-up • Elastography ○ Able to detect changes of fibrosis in affected bowel wall segments Fluoroscopic Findings • Upper GI/small bowel series ○ Aphthous ulcers: Earliest macroscopic change, central punctate barium with surrounding edema (target/bull's eye) ○ Cobblestone appearance: Linear and transverse ulcers with spared surrounding mucosa (pseudopolyps) ○ Luminal narrowing, ulceration; penetrating disease: Fistula or sinus tract CT Findings • CECT or CT enterography (CTE) ○ Wall thickening ○ Engorgement of vasa recta ("comb" sign) ○ Inflammation in mesentery ○ Reactive lymphadenopathy ○ Penetrating disease: Fistulae, sinus tracks, phlegmon/abscess ○ Luminal narrowing ± obstruction ○ Perianal disease ○ Enhancement of bowel wall; "target" or "double halo" sign MR Findings • MR enterography (MRE) ○ Similar findings to CT but without using ionizing radiation ○ Can assess peristalsis on free-breathing coronal sequences ○ Useful in evaluating perianal involvement Imaging Recommendations • Best imaging tool ○ Undiagnosed or suspected patients stratified into high or low risk based on symptoms, laboratory values, physical exam, and family history – Low risk: Ultrasound or MRE recommended – High risk: MRE or CTE ○ Newly diagnosed patients – MRE or CTE ○ Patients with established diagnosis of Crohn disease – Acute/emergent assessment: CT – Monitoring/longstanding complications: MRE • Protocol advice ○ Ultrasound – High-resolution, high-frequency linear transducer (> 10 MHz) □ Convex transducer for better penetration as needed (3-8 MHz) – Encourage clear, noncarbonated beverages prior to exam to help distend bowel – Graded compression – Harmonic imaging: Wide band preferred – Clips for assessment of bowel motility DIFFERENTIAL DIAGNOSIS Infectious Colitis • Shigella, Salmonella, Campylobacter, Escherichia coli O157:H, Yersinia, parasites, amebiasis • Clostridium difficile if recent antibiotic use • Cytomegalovirus in immunocompromised patients • Tuberculosis: Narrowed terminal ileum and cecum Diagnoses: Bowel 669

Crohn Disease Diagnoses: Bowel Ulcerative Colitis • Pancolitis without stricture, fistula, or sinus tract • "Backwash" ileitis • Continuous (no skip areas) Lymphoma • Non-Hodgkin lymphoma more common Mesenteric Adenitis • Common cause of right lower quadrant pain • Enlarged lymph nodes ± ileal wall thickening Appendicitis • Dilated appendix ± appendicolith, periappendiceal inflammation ± abscess PATHOLOGY General Features • Etiology ○ Exact etiology unknown but likely multifactorial ○ Possible causes – Environmental: Nutrition, smoking (4x increase), lifestyle – Immunobiologic: Altered bowel flora, abnormal response to unknown antigen • Genetics ○ Familial disposition ○ Many susceptibility loci for Crohn disease found on numerous chromosomes ○ High rate of concordance in monozygotic twins • Associated abnormalities ○ Extraintestinal disorders: Pyoderma gangrenosum, erythema nodosum, anemia, iritis/uveitis, primary sclerosing cholangitis, polyarticular and axial arthropathy, vitamin deficiency, nephrolithiasis ○ Associated autoimmune disorders: Asthma, autoimmune thyroiditis, vasculitis, multiple sclerosis, type 1 diabetes, psoriasis Staging, Grading, & Classification • Radiologic ○ Active inflammatory ○ Perforating and fistulizing ○ Fibrostenotic ○ Reparative and regenerative • Disease severity scored clinically using Crohn Disease Activity Index and Pediatric Crohn Disease Activity Index • Fecal markers (calprotectin and lactoferrin) helpful in diagnosis and monitoring disease Gross Pathologic & Surgical Features • Clearly defined normal segments of bowel between diseased segments ("skip lesions") • Early: Aphthous ulcers, lymphoid hyperplasia and edema, fissures, and transmural inflammation • Later: Transmural bowel wall inflammation, deep ulcers/fistulas, mesenteric inflammation • Chronic: Fibrotic change, stricture formation • Microscopic features ○ Edema, inflammation, and noncaseating granulomas CLINICAL ISSUES Presentation • Most common signs/symptoms ○ Recurrent abdominal pain and diarrhea • Other signs/symptoms ○ Malabsorption: Interrupted enterohepatic circuit with diminished absorption of bile salts in terminal ileum – Weight loss, fatigue, poor growth/weight gain in children, anemia, anorexia, nutritional deficiencies ○ Erythema nodosum and pyoderma gangrenosum ○ Obstruction Demographics • Age ○ 18-25 years, 20-30% of patients present under age of 20, smaller peak 50-80 years • Gender ○ M = F • Ethnicity ○ More common in Caucasian, Jewish populations • Epidemiology ○ Incidence: ~ 5 cases/100,000 population ○ Smoking: More aggressive disease phenotype Natural History & Prognosis • Increased risk of small bowel and colorectal cancer Treatment • Medical treatment: Mesalamine, steroids, antibiotics, probiotics ○ Bowel rest ○ Immunomodulators and biologic therapies for severe/refractory disease • Surgical treatment reserved for abscesses, complex perianal/internal fistulas unresponsive to medical therapy, fibrostenotic strictures with obstructive symptoms • Surveillance colonoscopy DIAGNOSTIC CHECKLIST Consider • Associated abnormalities in other organs (primary sclerosing cholangitis, arthritis, renal/biliary stones) Image Interpretation Pearls • Penetrating &/or stricturing disease alters clinical management SELECTED REFERENCES 1. Baumgart DC et al: US-based Real-time Elastography for the Detection of Fibrotic Gut Tissue in Patients with Stricturing Crohn Disease. Radiology. 141929, 2015 2. Anupindi SA et al: Imaging in the evaluation of the young patient with inflammatory bowel disease: what the gastroenterologist needs to know. J Pediatr Gastroenterol Nutr. 59(4):429-39, 2014 3. Anupindi SA et al: Common and uncommon applications of bowel ultrasound with pathologic correlation in children. AJR Am J Roentgenol. 202(5):946-59, 2014 4. Novak KL et al: The role of ultrasound in the evaluation of inflammatory bowel disease. Semin Roentgenol. 48(3):224-33, 2013 5. Rodgers PM et al: Transabdominal ultrasound for bowel evaluation. Radiol Clin North Am. 51(1):133-48, 2013 6. Baumgart DC et al: Crohn's disease. Lancet. 380(9853):1590-605, 2012 670

Crohn Disease<br />

Diagnoses: Bowel<br />

Ulcerative Colitis<br />

• Pancolitis without stricture, fistula, or sinus tract<br />

• "Backwash" ileitis<br />

• Continuous (no skip areas)<br />

Lymphoma<br />

• Non-Hodgkin lymphoma more common<br />

Mesenteric Adenitis<br />

• Common cause of right lower quadrant pain<br />

• Enlarged lymph nodes ± ileal wall thickening<br />

Appendicitis<br />

• Dilated appendix ± appendicolith, periappendiceal<br />

inflammation ± abscess<br />

PATHOLOGY<br />

General Features<br />

• Etiology<br />

○ Exact etiology unknown but likely multifactorial<br />

○ Possible causes<br />

– Environmental: Nutrition, smoking (4x increase),<br />

lifestyle<br />

– Immunobiologic: Altered bowel flora, abnormal<br />

response to unknown antigen<br />

• Genetics<br />

○ Familial disposition<br />

○ Many susceptibility loci for Crohn disease found on<br />

numerous chromosomes<br />

○ High rate of concordance in monozygotic twins<br />

• Associated abnormalities<br />

○ Extraintestinal disorders: Pyoderma gangrenosum,<br />

erythema nodosum, anemia, iritis/uveitis, primary<br />

sclerosing cholangitis, polyarticular <strong>and</strong> axial<br />

arthropathy, vitamin deficiency, nephrolithiasis<br />

○ Associated autoimmune disorders: Asthma, autoimmune<br />

thyroiditis, vasculitis, multiple sclerosis, type 1 diabetes,<br />

psoriasis<br />

Staging, Grading, & Classification<br />

• Radiologic<br />

○ Active inflammatory<br />

○ Perforating <strong>and</strong> fistulizing<br />

○ Fibrostenotic<br />

○ Reparative <strong>and</strong> regenerative<br />

• Disease severity scored clinically using Crohn Disease<br />

Activity Index <strong>and</strong> Pediatric Crohn Disease Activity Index<br />

• Fecal markers (calprotectin <strong>and</strong> lactoferrin) helpful in<br />

diagnosis <strong>and</strong> monitoring disease<br />

Gross Pathologic & Surgical Features<br />

• Clearly defined normal segments of bowel between<br />

diseased segments ("skip lesions")<br />

• Early: Aphthous ulcers, lymphoid hyperplasia <strong>and</strong> edema,<br />

fissures, <strong>and</strong> transmural inflammation<br />

• Later: Transmural bowel wall inflammation, deep<br />

ulcers/fistulas, mesenteric inflammation<br />

• Chronic: Fibrotic change, stricture formation<br />

• Microscopic features<br />

○ Edema, inflammation, <strong>and</strong> noncaseating granulomas<br />

CLINICAL ISSUES<br />

Presentation<br />

• Most common signs/symptoms<br />

○ Recurrent abdominal pain <strong>and</strong> diarrhea<br />

• Other signs/symptoms<br />

○ Malabsorption: Interrupted enterohepatic circuit with<br />

diminished absorption of bile salts in terminal ileum<br />

– Weight loss, fatigue, poor growth/weight gain in<br />

children, anemia, anorexia, nutritional deficiencies<br />

○ Erythema nodosum <strong>and</strong> pyoderma gangrenosum<br />

○ Obstruction<br />

Demographics<br />

• Age<br />

○ 18-25 years, 20-30% of patients present under age of 20,<br />

smaller peak 50-80 years<br />

• Gender<br />

○ M = F<br />

• Ethnicity<br />

○ More common in Caucasian, Jewish populations<br />

• Epidemiology<br />

○ Incidence: ~ 5 cases/100,000 population<br />

○ Smoking: More aggressive disease phenotype<br />

Natural History & Prognosis<br />

• Increased risk of small bowel <strong>and</strong> colorectal cancer<br />

Treatment<br />

• Medical treatment: Mesalamine, steroids, antibiotics,<br />

probiotics<br />

○ Bowel rest<br />

○ Immunomodulators <strong>and</strong> biologic therapies for<br />

severe/refractory disease<br />

• Surgical treatment reserved for abscesses, complex<br />

perianal/internal fistulas unresponsive to medical therapy,<br />

fibrostenotic strictures with obstructive symptoms<br />

• Surveillance colonoscopy<br />

DIAGNOSTIC CHECKLIST<br />

Consider<br />

• Associated abnormalities in other organs (primary<br />

sclerosing cholangitis, arthritis, renal/biliary stones)<br />

Image Interpretation Pearls<br />

• Penetrating &/or stricturing disease alters clinical<br />

management<br />

SELECTED REFERENCES<br />

1. Baumgart DC et al: US-based Real-time Elastography for the Detection of<br />

Fibrotic Gut Tissue in Patients with Stricturing Crohn Disease. Radiology.<br />

141929, 2015<br />

2. Anupindi SA et al: Imaging in the evaluation of the young patient with<br />

inflammatory bowel disease: what the gastroenterologist needs to know. J<br />

Pediatr Gastroenterol Nutr. 59(4):429-39, 2014<br />

3. Anupindi SA et al: Common <strong>and</strong> uncommon applications of bowel<br />

ultrasound with pathologic correlation in children. AJR Am J Roentgenol.<br />

202(5):946-59, 2014<br />

4. Novak KL et al: The role of ultrasound in the evaluation of inflammatory<br />

bowel disease. Semin Roentgenol. 48(3):224-33, 2013<br />

5. Rodgers PM et al: Transabdominal ultrasound for bowel evaluation. Radiol<br />

Clin North Am. 51(1):133-48, 2013<br />

6. Baumgart DC et al: Crohn's disease. Lancet. 380(9853):1590-605, 2012<br />

670

logo

products

Resources

Company

Terms of service
Privacy policy
Cookie policy
Cookie settings
Imprint
Change language
Made with love in Switzerland
© 2024 Yumpu.com all rights reserved

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!