13/11/55 IMAGING MODALITIES Improve reading skill of abdominal imaging • PLAIN FILM • ULTRASONOGRAPHY • BARIUM EXAMINATION ผศ นพ สิทธิพงศ ศรีสัจจากุล BODY IMAGING • CT Department of Radiology, SirirajHospital, • MRI MahidolUniversity • PET @ King ChulalongkornMemorial Hospital, 25 november12 PLAIN FILM • ACUTE ABDOMINAL SERIES -CXR upright PLAIN FILM -Plain abdomen supine and upright Density in Plain Film Plain Abdomen: Upright View 3 Liver 4 2 3 1 1 = air Properitoneal 2 = fat fat line 4 Abdominal 3 = soft tissue wall 5 4 = bone Small bowel loops 5 = metallic 1 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 Plain Abdomen: Supine View Plain Abdomen vs Plain KUB Transverse Stomach colon Descending colon Supine Plain KUB PLAIN ABDOMEN How to read plain abdomen 1 Abdominal wall and properitonealfat line 2 Distance between bowel wall and abdominal Peripheral to central approach or vice versa wall 3 Gas distribution in GI tract ( stomach, small bowel and large bowel) 4 Soft tissue density in abdomen such as solid organs, fluid-filled bowel loops PLAIN ABDOMEN 5 Bony structures 6 Detection of abnormalities -Abnormal gas -free air , bowel dilatation, pneumatosis -Abnormal mass -intraperitoneumor retroperitoneum -Organomegaly -Abnormal calcification -Foreign bodies 2 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 ABNORMAL PLAIN FILM CXR upright moderate to marked pneumoperitoneum Plain abdomen upright triangular sign • ICU admission • Sick patient • No upright film liver diaphragm ascites Triangular sign 3 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 • Cupola sign • Cupola sign • Free air outline • Free air outline visceral structures visceral structures • Air outline lateral umbilical ligament Pneumoperitoneum Pneumoperitoneum Left lateral decubitus film!!!! helpful 4 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 SBO vs LBO • Position of bowels – Small bowel: central – Large bowel: periphery • Folds: – Small bowel: valvulae conniventes – Large bowel: haustra • Diameter – Small bowel: 3cm Small bowel obstruction – Large bowel: 6cm, cecum 9 cm Ileus vs Gut Obstruction Paralytic Ileus • Proportion of prox. and distal bowels • Upright view: air fluid level • Thickness of bowel wall • Bowel sound • Follow up film String of beads • String of pearl sign • curvi-linear arrangement of air bubbles • valued sign of obstruction (as opposed to ileus) • small bubbles of air trapped in the valvulae of the fluid filled small bowel. 5 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 Slit/Stretch Sign -small amounts of air caught in the valvulaeof fluid- filled bowel -highly suggestive of small bowel obstruction. Coil spring sign Gasless small bowel obstruction • small bowel loops are filled with normal small bowel content -dilated air-filled small bowel -most noticeable in the jejunum where the valvulae conniventesare closely spaced. Imaging features of SBO SMALL BOWEL OBSTRUCTION • Air filled Coil spring sign • PLAIN FILM • Partial fluid-filled Multiple air fluid levels Detectable radiographic sign but no identifiable cause • Nearly complete fluid –filled String of beads Slit/strecthsign • Complete fluid -filled Gasless SBO 6 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 Colonic volvulus FAQ • 11 % of all volvulus • Deficient peritoneal fixation of cecum The Gas in the Rectum • Younger patients than sigmoid volvulus Ignore or Important? • 30-60 years • 2 types( axial and loop type) • Location of caput cecum • DDX -Cecal bascule Gas in the rectum is widely considered a useful indicator to exclude bowel obstruction • This sign is unreliable. • Bowel is often partially obstructed, allowing the • A lack of gas in the rectum is worthy of passage of bowel contents past the level of the consideration partial obstruction. • Gas in the rectum does not exclude bowel obstruction • More importantly, the large bowel produces its own gas through fermentation processes • A collapsed large bowel is a more reliable sign of bowel obstruction • Even in cases of complete obstruction, gas in the rectum may persist for several days • Introduce via PR exam Abnormal Calcifications Gallstones • Gallstone • KUB stone • Calcified organs -Pancreas, nodes • Calcified old granuloma -liver , spleen • Calcified mass 8 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 Calcified Pancreas Calcified Nodes Calcified Splenic Granuloma Calcified Uterine Fibroid Foreign Body: opaque Foreign body 9 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 Coin in Esophagus vs Trachea Ultrasonography Esophagus Trachea Ultrasound • PROS – No radiation, no contrast – Real time and portable – Cheap and available – Multiplanar – Good for DDx cyst / mass – Good for vascular evaluation ( doppler ultrasound) • CONS – Not suitable in obesity – Not suitable for bowel evaluation – Operator dependent Normal Liver Normal Ultrasound 1 2 3 PV/CD Pancreas Spleen 10 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 Normal Kidneys Terminology 1 2 3 • Echogenicity -high : soft tissue , fat, hemorrhage, calcification -intermediate : soft tissue -low: cyst or fluid content RL/RK RK LK Liver Mass Ascites LV Bile Duct Dilatation shadowing Posterior acoustic Posterior acoustic shadow enhancement 11 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 shadowing shadowing Dirty shadowing Dirty shadowing • Posterior acoustic enhancement cystic lesion ( simple cyst or cystic tumor) • Posterior acoustic shadow calcified lesion ( GS, renal stone) • Dirty shadowing air or gas ( aerobilia, emphysematous cholecystitis or pyelonephritis) • No shadowing mass or soft tissue fat Acute calculous cholecystitis Acute acalculousemphysematous cholecystitis RLQ pain 12 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 Acute appendicitis • Dilated appendix • Diameter morethan 6 mm • Appendicolith • Periappendiceal abscess • Pro: – See mucosal / intraluminal lesion – Real time Barium examination – Dynamic study [anatomy and movement (peristalsis)] • Cons: – Radiation – Contrast use: barium or water soluble contrast – Need experience of performer Barium Swallowing: Spot Films – Barium swallowing or Esophagography – Upper GI study/series (UGIS) or GI single meal (GISM) – GI follow through (GIFT) or Long GI study or Small bowel series valleculae – Barium Enema • Single and double contrast pyriform Valleculae sinuses – Others: pyriform • Loopography sinuses 13 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 Esophagus AP view Esophagus oblique view Barium Swallowing: Overhead Film Diaphragm EG junction Esophagus AP view Esophagus oblique view Oblique view AP view Mucosal Detail UGIS: Spot Views GI Follow Through GI Follow Through 14 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 Normal BE Single vs Double Contrast A. Ileocecal valve H B. Terminal ileum F C. Appendix D. Cecum E. Ascending G I colon E F. Hepatic flexure G. Transverse colon D J C H. Splenic flexure I. Descending A B colon K J. Sigmoid colon K. Rectum Spot Film Overhead Film Barium Enema: Overhead Barium Enema: Spot Pattern Approach IMPORTANCE !! • Outpouching lesion -Ulcer, diverticulum • • Questionable small or large bowel Intrinsic filling defect obstruction -Polyp or malignancy – Start with barium enema to rule out large • Extrinsic pressure effect bowel obstruction • Narrowing of lumen -Stenosis, circumferential mass • Fold thickening -regular , irregular : short or long segment • Leakage of contrast (extravasation) and fistula 15 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 Intrinsic vs Extrinsic Intrinsic vs Extrinsic • DDx when fully distended bowel • Angle – Intrinsic : acute angle – Extrinsic: obtuse angle • Mucosa – Intrinsic: irregular or smooth – Extrinsic: smooth • Mass effect – Intrinsic: no – Extrinsic: yes Narrowing of Lumen Stenosis vs Annular Lesion • Stenosis (A) – Smooth or irregular – Tapering • Circumferential mass (annular lesion) (B) – Irregular – Abrupt change A B 16 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 Two conditions !!!!! • classic films • detectable cause aerobilia portal venous gas Sigmoid volvulus Coffee bean sign 7 PDF created with pdfFactory Pro trial version www.pdffactory.com 13/11/55 Conclusion • Plain film -normal density Case examples -imaging approach • Ultrasound -terminology -shadowing • Barium examination -modalities -single and double contrast 17 PDF created with pdfFactory Pro trial version www.pdffactory.com.