focal vs diffuse gall bladder wall thickening

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  • 1.Focal Vs Diffuse Gall Bladder Wall Thickening

2. Objectives Normal GB wall Appearance Causes Of focal GB wall thickening Causes of diffuse GB wall thickening Appearances of different conditions Differentiating points Pitfalls of GB wall thickening 3. Gall Bladder Normal wall thickness < 3mm The normal gallbladder wall appears as a pencil-thin echogenic line at sonography. The thickness of the gallbladder wall depends on the degree of gallbladder distention and pseudothickening can occur in the postprandial state. 4. LEFT: US of a normal gallbladder after an overnight fast shows the wall as a pencil-thin echogenic line (arrow).RIGHT: US in the postprandial state shows pseudothickening of the gallbladder 5. The normal gallbladder wall is usually perceptible at CT as a thin rim of soft-tissue density that enhances after contrast injection. 6. Thickened gallbladder wall Thickening of the gallbladder wall is a relatively frequent finding at diagnostic imaging studies. A thickened gallbladder wall measures more than 3 mm, typically has a layered appearance at sonography , and at CT frequently contains a hypodense layer of subserosal oedema that mimics pericholecystic fluid. 7. LEFT: US in a 59-year-old woman with acute cholecystitis shows the layered appearance of a thickened gallbladder wall, with a hypoechoic region between echogenic lines RIGHT: At contrast-enhanced CT the thick-walled gallbladder contains a hypodense outer layer (arrow) due to subserosal oedema 8. Focal Wall Thickening Polyps Adenomyomatosis Carcinoma Xanthogranulomatous cholecystitis Metastasis Chronic cholecystitis Tumefactive sludge / Sludge balls 9. Polyps/ Cholesterolosis A condition in which triglycerides, cholesterol esters and cholesterol precursors are deposited in lamina propria of GB. Cause is unknown Not related to serum lipid level, atherosclerosis, diabetes, cholesterol stones, or hyperconcentration of cholesterol in bile. Most cases do not produce any detectable change in appearance. 10. Sometimes referred to as Strawberry gallbladder Minority of cases are of polypoid variety Cholesterol polyps are enlarged papillary fronds filled with lipid laden macrophages Attached to the wall by a stalk Ball on the wall 5mm or less, rarely get bigger than 10mm 11. Do not acoustic shadowing Do not exhibit postural movement Other less common types of polyps are adenoma papilloma leiomyoma lipoma neuroma 12. Polyps < 5mm no further evaluation 5-10mm monitoring > 10mm should be removed As the polyp enlarges risk of malignancy increases 13. Large Fibrous Polyps of the Gallbladder Simulating Gallbladder Carcinoma 14. GB Polyp fixed to the ventral wall of the GB 15. Diffuse Wall Thickness CAUSES Biliary Causes 1.Cholecystitis 2.Adenomyomatosis 3.Cancer 4.AIDS cholangiopathy 5.Sclerosing cholangitis 16. NON BILIARY CAUSES 1.Hepatitis 2.Pancreatitis 3.Heart Failure 4.Hypoproteinemia 5.Cirrhosis 6.Portal hypertension 7.Lymphatic obstruction 17. Cholecystitis Acute Chronic Acalculous Xanthogranulomatous 18. Acute cholecystitis Fourth most common cause of hospital admissions for patients presenting with an acute abdomen It is the prime diagnostic concern when a thick-walled gallbladder is found at imaging. This feature, however, is not pathognomonic and additional imaging signs should be present to support the diagnosis of acute calculous cholecystitis. 19. Signs of Acute cholecystitis Thickened gall bladder wall Obstructing gallstone Hydropical dilatation of the gallbladder, A positive sonographic Murphy's sign ( i.e., pain elicited by pressure over the sonographically located gallbladder), Pericholecystic fat inflammation or fluid Hyperemia of the gallbladder wall at power Doppler 20. Acute calculous cholecystitis. Transverse sonogram at the spot of maximum tenderness shows a non- compressible hydropically distended thick-walled gallbladder (arrowheads), with an intraluminal stone and sludge or debris. Contrast-enhanced CT depicts extensive fat inflammation (arrowheads) surrounding the gallbladder (arrow). 21. Chronic cholecystitis Chronic cholecystitis is a term used clinically to refer to symptomatic gallbladder stones that cause transient obstruction, leading to a low-grade inflammation with fibrosis . Correlation of the imaging finding of a stone-containing slightly thick-walled gallbladder with the clinical history is critical. 22. Chronic cholecystitis. Longitudinal sonogram of the gallbladder shows slight wall thickening (arrow) and an intraluminal non-obstructing stone 23. Acalculous cholecystitis Mainly occurs in critically ill patients, (Major surgery, Major trauma,extensive burns) Due to Increased bile viscosity from fasting and Medication that causes cholestasis. The imaging features are those of acute cholecystitis, except for the absence of stones whereas gallbladder sludge is usually present. 24. Acalculous cholecystitis PITFALL Because in critically ill patients gallbladder abnormalities are frequently found secondary to systemic disease , acalculous cholecystitis can be difficult to diagnose . In these patients a percutaneous cholecystostomy can be both diagnostic and therapeutic. 25. 74-year-old man with acute acalculous cholecystitis. LEFT: US at the spot of maximum tenderness shows mural thickening of the gallbladder (arrow) that is completely filled with sludge (asterix) without any stones.RIGHT: Power-Doppler sonography shows hypervascularity of the gallbladder wall (arrowhead), as a supporting sign of inflammation. 26. Xanthogranulomatous cholecystitis Unusual variant of chronic cholecystitis, Characterized by a Destructive inflammatory process with varying proportions of fibrous tissue, inflammatory cells and lipid laden macrophages Gall stones +/- Locally invasive 27. Imaging studies show marked gallbladder wall thickening, often containing intramural nodules that are hypoechoic at sonography and hypoattenuating at CT, representing abscesses or foci of xanthogranulomatous inflammation. These features overlap with those of gallbladder carcinoma, making preoperative distinction between these entities often impossible. 28. Xanthogranulomatous cholecystitis. LEFT: US shows marked wall thickening with intramural hypoechoic nodules (arrowheads), and an intraluminal stone (arrow).RIGHT: Contrast-enhanced CT shows a deformed and thickened gallbladder wall containing hypoattenuating nodules 29. Contrast-enhanced CT shows a deformed and thickened gallbladder wall containing hypoattenuating nodules . These represent abscesses or foci of inflammation. The lumen contains several stones (arrow). 30. Adenomyomatosis Benign condition that requires no specific treatment, Incidental finding in upto 9% of cholecystectomy specimens Characterized by 1. Epithelial proliferation, 2. Muscular hypertrophia and 3. Intramural diverticula (Rokitansky-Aschoff sinuses), which may segmentally or diffusely involve the gallbladder. 31. The sonographic finding of cholesterol crystals, shown as 'comet-tail' reverberation artifacts, within a thickened wall of the gallbladder strongly suggests this diagnosis. Air may produce a similar artifact, however, patients with emphysematous cholecystitis are usually ill in contrast to those with adenomyomatosis. MR imaging may be able to differentiate adenomyomatosis from gallbladder carcinoma by depicting Rokitansky-Aschoff sinuses. 32. Four types of gallbladder adenomyomatosis A. Annular type. B. Segmental type, which describes an annular or segmental wall thickening causing stricture that divides the gallbladder lumen into separate interconnected compartments. C. Fundal type,(adenomyoma) a focal elevated lesion with a central dimple located at the fundus of the gallbladder. D .Diffuse type, a thickened wall involving the entire gallbladder. 33. Exclusion of gallbladder cancer may be most problematic in segmental and focal cases. Focal adenomyomatosis may appear as a discrete mass, known as an adenomyoma. 34. Diffuse adenomyomatosis of gall bladder. These gall bladder ultrasound images show multiple echogenic foci within the GB wall with V-shaped comet-tail . 35. Gallbladder Adenomyomat osis: Axial CT of the abdomen with oral and IV contrast shows focal thickening of the gallbladder wall (arrows) 36. Oral cholecystogram and MRCP Historically oral cholecystograms were performed, however due to low sensitivity and a high rate of contrast allergies it has now largely been replaced by MRCP which does not rely on contrast opacification of the lumen of the gallbladder. MRCP would be also to detect : mural thickening focal sessile mass pearl necklace sign (fluid filled intramural diverticula) hourglass configuration in annular types 37. Rokitansky-Aschoff sinuses shown on the after fatty meal film at cholecystography Stricture is also present. 38. Fundal nodule of adenomyomatosis before and after gallbladder contraction. 39. MRI The pearl necklace sign alludes to the characteristically curvilinear arrangement of multiple rounded hyperintense intraluminal cavities visualized at T2- weighted MR imaging and MR cholangiopancreatography of adenomyomatosis. 40. pearl necklace sign It represents the contrast / fluid filled intramural mucosal diverticula (Rokitansky-Aschoff sinuses) which line up reminiscent of pearls on a necklace. highly specific (92%) frequently not seen, only present in ~ 70% of cases 41. coronal T2 42. Gallbladder carcinoma Fifth most common malignancy of the GIT found incidentally in 1% to 3% of cholecystectomy specimens. It is often detected at a late stage of the disease, due to lack of early or specific symptoms. Gallbladder carcinoma has various imaging appearances, ranging from a - polypoid intra-luminal lesion to -an infiltrating mass replacing the gallbladder, -diffuse mural thickening. 43. Associated findings -- invasion of adjacent struct