บทความวชาการิ Non-Traumatic Abdominal Emergency Imaging Hepatobiliary Emergency จฬาลุ กษณั ์ พรหมศร ภาควิชารังสีวิทยา คณะแพทยศาสตร์ มหาวิทยาลัยขอนแก่น Non Traumatic Abdominal Emergency Imaging invasive amebiasis Hepatobiliary Emergency o Antibody to Entamoeba rising - Liver abscess o trophosoites ascend via portal vein then - Cholangitis invaded parenchyma - Acute cholecystitis o chocolate-colored, pasty material (anchovy - Gall stone ileus paste) - Mirizzi syndrome o single/multipe Periperheral near capsule Pancreatitis - Fungal liver abscess Appendicitis o Pts hematologic malignancy or compromised Small bowel obstruction o Microabcess involving liver, spleen and Peptic Ulcer perforation kidneys Mid gut volvulous o Leukemia/ most common Candia albicans Sigmoid volvulous o Other; Cryptococcus, histoplasmosis, Mesenteric vascular ischemia mucormycosis, Aspergillus Diverticulitis o Size 2-20 mm Imaging tools Acute abdomen series Imaging; Chest upright - Plain film; hepatomegaly, intrahepatic gas/an Abdomen upright fluid level Abdomen supine - US: Left lateral decubitus o variable in shape and echo (hypoechoic, Ultrasound hyperechoic, anechoic) with septation, fluid level CT without and with posterior enhancement MRI o Amebic; round/oval hypoechoic mass abuts liver capsule Liver abscess o Fungal; multiple tiny small echoic lesions - Pyogenic liver abscess scattered through liver parenchyma o(K pneumonia, E coli, Enterococcus, o US, CT 4 patterns of hepatosplenic Burkholderia, Streptococcus, and Staphylococcus spe- candidiasis cies) 1. wheel-within-a wheel; central hypoechic of o Solitary necrosis containing fungal, surrounded echogenic o Multiple inflammatory cells o Few mm- cm 2. Bull’s-eye of central echogenic nidus surrounded - Amebic liver abscess by hypoechoic rim( pts active fungal infection with nor- o Amebic liver abscess; E.Histolytica mal white cell) o most common extraintestinal from of 3. a uniform hypoechic nodules, most common; DDX การประชุมวิชาการ ครงทั้ ี่ 30 ประจำปี 2557 5 Srinagarind Med J 2014;29 (Suppl) with metastasis, lymphoma - Rarely ectopic gall stone migrate proximally 4. Echogenic foci with variable posterior acoustic causing gastric outlet obstruction shadowing, lateral stages and indicates early resolution - Rigler’s triad; pneumobilia, ectopic gall stone - CT and evidence of bowel obstruction - cluster, complex peripheral ring enhancement of Mirizzi Syndrome hypoattenuation (0-45 HU) and edematous changed of - May occur as an acute presentation of ชาการ ิ adjacent liver parenchyma cholelithiasis or setting of acute cholecystitis - MRI - Impacted gall stone in the GB neck or cystic - T1WI; hypointense, T2WI; hyperintense and duct causing biliary tree obstruction peripheral ring enhancement with edematous changed - Direct compression of adjacent CHD or บทความว of surrounding liver parenchyma secondary local inflammation causing bile duct wall Cholangitis; infectious pyogenic cholangitis, OV edema and fibrosis - US; dilatation of IHD, CBD with evidence of - RQU pain, fever and leukocytosis, acute onset stone of obstructive jaundice - CT; dilated biliary tree with periductal - US findings enhancement, stones, sludge, pneumobilia and abscess o Gall stone located within GB neck or cystic duct and dilated CHD and IHD Acute cholecytitis o Normal caliber of CBD - 90–95% of cases occur in the setting of cystic o Pericholecystic and peribiliary duct duct or gallbladder neck obstruction related to cholelithi- inflammation changes asis o GB wall thickening - Middle age obese woman - Murphy’s sign positive Acute Pancreatitis - Plain film; gall stones Enlargement of pancreas, fluid collection, - US; sensitivity 80-100%, Specificity 60-100% obliteration of fat plane o Specific finding Plain film; sentinel loop, colon cut-off sign, gas in y Cholelithiasis duodenum, non specific finding y Gall bladder wall thickening >3-5 mm CT; focal or diffused enlargement of pancreas with y Pericholecystic fluid heterogeneous enhanancement (necrosis; non y Positive sonographic Murphy’s sign enhancement), fluid collections, infiltration of o Less specific peripancreatic fat, abscess, pseudocyst, hemorrhage y Gall bladder wall distention without or with gall stones y GB sludge Appendicitis - Acute Complicated cholecystitis Plain film abnormalities seen in <50% o Gangrenous cholecystitis and GB - Calcified, frequently laminated, appendicolith in perforation RLQ (in 7-15%) o Emphysematous cholecystitis - Cecal ileus” = local paralysis o Suppurative cholecystitis - Small bowel obstruction pattern o Hemorrhagic cholecystitis - Soft-tissue mass and paucity or absence of intestinal gas in RLQ (more often with perforation) Gall stone ileus - Extraluminal gas bubbles (again more often in - Gall stone lodge in terminal ileum near IC valve perforation) (small bowel anywhere, colon) US ; (77-94% sensitive, 90% specific, 78-96% 6 การประชุมวิชาการ ครงทั้ ี่ 30 ประจำปี 2557 Srinagarind Med J 2014;29 (Suppl) accurate) the SMB is almost completely filled w/ fluid, diagnostic - Visualization of noncompressible appendix as of SBO in most cases a blind-ending tubular aperistaltic structure (seen only - Pneumoperitoneum; sign of bowel perforation in 2% of normal adults, but in 50% of normal children) CT; - Diameter >6 mm in total diameter on cross - Small bowel obstruction? บทความว section (81%) with 2mm mural thickness - Level of obstruction - Diffuse hypoechogenicity (associated with - Cause of obstruction higher frequency of perforation) - Complication of obstruction ิ - Lumen may be distended with anechoic / Peptic Ulcer perforation ชาการ hyperechoic material Perforation of peptic ulcer causing free air within - Visualization of appendicolith (6%) peritoneal cavity - Localized periappendiceal fluid collection Mid gut volvulous - Prominent hyperechoic mesoappendix / Torsion of entire gut around superior mesenteric pericecal fat artery (SMA) due to a short mesenteric attachment of CT (87-98% sensitive, 83-97% specific, 93% accurate) small intestine in malrotation - Distended lumen Plain film findings - Circumferentially thickened and enhancing wall o Dilated, air-filled duodenal bulb and paucity of - Appendicolith = homogeneous / ringlike gas distally calcification (25%) - “Double bubble sign” = air-fluid levels in - Periappendicular inflammation-linear streaky stomach and duodenum densities in periappendicular fat o Isolated collection of gas-containing bowel - Pericecal soft-tissue mass loops distal to obstructed duodenum = gas-filled - Abscess volvulus = closed-loop obstruction o Poorly encapsulated - From nonresorption of intestinal gas o Single or multiple fluid collection(s) with air secondary to obstruction of mesenteric veins o Extraluminal contrast material Barium studies - Focal cecal wall thickening (80%) o Duodenojejunal junction (ligament of Treitz) - “Arrowhead” sign = funnel of contrast medium located lower than duodenal bulb and to the right of in cecum centering about occluded orifice of appendix expected position Small bowel obstruction o Spiral course of midgut loops = “apple-peel / Supine Abdomen film twisted ribbon / corkscrew” appearance (in 81%) - Centrally dilated small bowel loops above the US findings obstructed site, with little or no gas distally o Clockwise whirlpool sign = color Doppler (disproportionately dilated proximal bowel compared to depiction of mesenteric vessels moving clockwise with distal bowel) caudal movement of transducer - The dilated loops often stacked one under the o Distended proximal duodenum with other in a “stepladder appearance” arrowhead-type compression over spine - Prominent valvulae conniventes in dilated loops o Superior mesenteric vein to the left of SMA Upright Abdomen film o Thick-walled bowel loops below duodenum and - Multiple air-fluid levels with different heights (2 to the right of spine associated with peritoneal fluid different levels) in the same loop (“candy cane CT findings appearance” or hairpin loop) y Whirl-like pattern of small bowel loops and - “String- of- beads (pearls)” sign, seen later when adjacent mesenteric fat converging to the point of การประชุมวิชาการ ครงทั้ ี่ 30 ประจำปี 2557 7 Srinagarind Med J 2014;29 (Suppl) torsion (during volvulus) y Intraluminal thrombus in involved vessel y SMV to the left of SMA (NO volvulus) o Mesenteric angiogram y Chylous mesenteric cyst (from interference y Can distinguish between arterial embolic and with lymphatic drainage) thrombotic causes of acute mesenteric ischemia Sigmoid volvulous Diverticulitis Twisting of loop of sigmoid around its mesenteric Herniation of mucosa and submucosa through ชาการ ิ attachment site muscular layers pseudodiverticulum=false Abdominal plain films usually diagnostic diverticulum=pulsion type y Inverted U-shaped appearance of distended Plain Film X-ray sigmoid loop • Sentinel loop or, less likely, LBO บทความว y Largest and most dilated loops of bowel are • Air bubbles in abscess seen with volvulus • Pneumoperitoneum (rare) y Coffee-bean sign เ midline crease BE corresponding to mesenteric root in a greatly distended • Extraluminal contrast sigmoid • Pericolonic abscess produces mass effect y Sigmoid volvulus – bowel loop points to RUQ • Double-tracking=barium in longitudinal sinus y Cecal volvulus – bowel loop points to LUQ tract in wall o Dilated cecum comes to rest in left • Spasm is an indirect sign of diverticulitis upper quadrant • Fistula to bladder (diverticulitis is most y Bird’s-beak or bird-of-prey sign เ seen on common cause of non-traumatic fistula here) or small barium enema as it