US in non-traumatic acute abdomen. Lalita, M.D. Radiologist Department of radiology Faculty of Medicine ChiangMai university

Transcription

1 US in non-traumatic acute abdomen Lalita, M.D. Radiologist Department of radiology Faculty of Medicine ChiangMai university

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3 Sagittal Orientation

4 Transverse (Axial) Orientation

5 Coronal Orientation

6 Intercostal Imaging plane

7 : Hyperechoic 2: Hypoechoic 3: Anechoic 4: Posterior acoustic enhancement 5: Posterior acoustic shadow

8 Specific terms for US Hyperechoic : White Fat, air, calcification Posterior acoustic shadow Hypoechoic : Grey Soft tissue, turbid fluid Anechoic : Black Clear fluid cyst, gallbladder, bile duct, vessels Posterior acoustic enhancement

9 Liver abscess

10 Liver abscess Early suppuration: solid with altered echogenicity, usually hypoechoic

11 Liver abscess Frankly purulent: cystic, with the fluid ranging from echo free to highly echogenic Posterior enhancement

12 Liver abscess Gas-producing: echogenic foci with a posterior reverberation artifact Fluid-fluid interfaces, internal septations, debris Wall: well defined, irregular, thick

13 Specific terms for US Reverberation artifact Gas Additional echo from repeat reflection (two strong parallel reflectors) Series of bright bands (step ladder) Cannot see image beneath the gas

14 Liver abscess HCC

15 1 2

16 Gallstones 15-20% GS: detect on plain film. US: most sensitive in detection of GS Mobile Echogenic structure Acoustic shadowing in the lumen of the gallbladder

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19 Impacted gallstone A gallbladder completely filled with stones Wall-echo-shadow (WES) complex 1 st line: GB wall 2 nd line: bright echo of the stone 3 rd line: acoustic shadowing

20 Acute cholecystitis Gallstones Gallbladder wall thickening > 3 mm Gallbladder enlargement > 4x10 cm Positive sonographic Murphy s sign Pericholycystic fluid

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23 1 Gallstone with acute cholecystitis 2 Symptomatic gallstone

24 Renal stone

25 Calculi Common finding, in collecting system Multiple predisposing conditions: No cause is identified in most patients Most are hyperechoic with posterior acoustic shadowing Non-obstructing caliceal calculi: usually asymptomatic*

26 Calculi US: Sensitivities in detection of calculi is 12% to 96% Depend on location (renal or ureteral), composition, and sizes of calculi Stones greater than 5 mm were detected with 100% sensitivity by ultrasound Operator technique clearly impacts the ability of ultrasound to depict renal calculi

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30 Calculi Color Doppler may also improve the detection of small, minimally shadowing 83% urinary tract stones show color and power Doppler sonographic twinkling artifacts

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35 A B

36 Anatomy Normal kidney. A, Sagittal, and B, transverse, sonograms of normal anatomy with corticomedullary differentiation show relatively hypoechoic medullary pyramids, with cortex slightly less echogenic than the liver and spleen.

37 A B

38 Nephrocalcinosis Renal parenchymal calcification The calcification may be dystrophic or metastatic Dystrophic: deposition of calcium in devitalized (ischemic or necrotic) tissue : tumors, abscesses, hematoma Metastatic: most often with hypercalcemic states caused by hyperparathyroidism, RTA, and renal failure : cortical or medullary

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41 Renal stone 1 renal stone 2 small renal stones 3 renal stone 4 medullary nephrocalcinosis

42 Stone? 1. Yes 2. No

43 2

44 Renal artery calcification

45 ENTITIES THAT MIMIC RENAL CALCULI Intrarenal gas Renal artery calcification Calcified sloughed papilla Calcified transitional cell tumor Alkaline-encrusted pyelitis Encrusted calcification of ureteric stent

46 Calculi If a stone passes into the ureter: three areas of ureteric narrowing: uteropelvic junction (UPJ) ureter crosses the iliac vessels ureterovesical junction (UVJ).

47 Ureteral calculi Difficult at sonography because of overlying bowel gas and the deep retroperitoneal location of the ureter Identified as hyperechoic focus with sharp, distal acoustic shadowing within the ureteric lumen

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49 Left RC with mild hydronephrosis

50 Moderate hydronephrosis

51 Severe hydronephrosis

52 Low level echoes within the dilated PCS may represent pus. Sometimes, the urine may appear anechoic, despite being infected. The clinical history should help differentiate pyo- from simple hydronephrosis. Pyonephrosis

53 Appendix

54 Acute appendicitis A positive sonographic McBurney sign Blind-ending tubular structure Greater than 6 mm in outer diameter Non-compressible The increased flow in the appendiceal wall or periappendiceal space using color Doppler sonography

55 An additional positive finding An appendicolith Peritoneal fluid Hyperechoic periappendiceal fat Cecal wall thickening A RLQ fluid collection without visualization of the inflamed appendix raised suspicion for perforated appendicitis and periappendicular abscess.

56 Appendicitis

57 Appendicitis with appendicolith

58 Thank you