Liver ppt..pptx- Liver Computed Tomography

Liver Computed Tomography

1. In The Name Of God 1

2. Liver CT scan 2

3. Prepared by: Seyedeh Shabnam Mousavi Gezafroodi 3

4. Anatomy Liver is the largest gland & visceral organ of body Weight: 1500 gr Location: typically right hypochondriac & epigaster With 2 surface : diaphragmatic S. & visceral S. With 8 segments Has 4 lobe : R , L , quadrate, caudate 4

5. Method Of Diagnosis Ultrasound CT scan MRI Liver biopsy 5

6. COMPUTERIZED TOMOGRAPHY serves as an ideal screening examination for the entire abdomen and pelvis. Recent technological advances in CT technology, have further improved the performance of CT scanners in terms of speed of acquisition, resolution, and the ability to image the liver during various phases of contrast enhancement Its limitations include the need for a high radiation dose and a low sensitivity for the detection and characterization of lesions smaller than 1 cm . 6

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8. L iver Anatomy on CT 8

9. Be fasting 3-4 hour before examination Contrast-enhanced CT is contraindicated in patients with a history of anaphylaxis from contrast agents and renal failure also for patients who were under barium study less than 1 week before CT examination Preparation 9

10. Routine Abd & Pel 3 phasic Recommendation 10

11. Technique 11

12. Which one isn’t useful for reconstruction of liver CT? MIP MPR VRT 3D 12

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18. Contrast- Enhanced CT Purpose of use of IV contrast media in liver CT scan is Enhancement system of blood in liver: hepatic artery portal vein Portal level= It takes 70s to detect Metastasis in points with low density Arterial level=30s after of injection of CM , Hematum , Hemangiom , and metastasis are detected with Enhancement 18

19. 19 Contrast- Enhanced CT (cont.)

20. Non Contrast Enhancement-CT It is usually utilized in patient with a history or prior contrast reactions Non contrast scan are helpful in detecting metastases from hyper vascular tumors Density of liver is more than of density of soft tissue , it is more than of density of spleen , too Density of portal &hepatic veins is lesser than hepatic parenchyma Angyal branches can be in different forms and should not be mistake with metastasis . 20

21. Normal protocol Contiguous 1cm section about 20-30 section Kv = 120 , mAs = 4 00 for enhanced images 400-600 mL C.M Injection flow: 3-4 mL/s large FOV pitch factor: 1.5 or less 21

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23. True Or False In contrast enhanced CT Liver parenchyma enhances more than Liver veins 23

24. Indication Liver Neoplasms : -Benign Neoplasms -Malignant Neoplasms Diffuse Diseases : -fatty infiltration -cirrhosis - hemochromatosis - Glycogen storage disease Hepatic cysts Inflammatory Disease : -pyogenic Abscess -fungal Abscess -Amebic Abscess Vascular Disease : portal vein thrombosis Trauma 24

25. Benign mass of the liver Non traumatic , non infectious , space occupying liver lesion Most types of them remain unsuspected & undetected until a incident discovery With current method of imaging ,The detection of benign hepatic lesions, their identification & complication is more easily achieved than histologic diagnosis 25

26. Hemangyoma Focal nodular hyperplasia Hepatic cell adenoma Benign mass of liver (Cont.) 26

27. Hemangyoma is the most common type of hepatic tumor demonstrated like enlarged blood- filled vascular space dimensions › 15 µm blood circulate very slowly through sinusoids 27

28. Hemangyoma (cont.) isn’t encapsulated but are sharply defined they are single or multiple, in variety of size discovered incidentally by CT or Sonography contrast enhancement & time following contrast affect on appearance of hemangyoma on CT image 28

29. Hemangyoma (cont.) hypodense compared to normal liver Hyperdense to fatty liver 29

30. Hemangioma in 56-year-old man with gastric carcinoma. Preoperative CT scan obtained during portal venous phase shows small hypoattenuating hepatic lesion (arrow) with no discernible area of enhancement. 30

31. H emengioma 31

32. Focal nodular hyperplasia an uncommon tumor of liver found at physical examination hepatic imaging or laparotomy there is a significant relationship between this lesion & use of oral contraceptives often occur as a solitary mass in sub capsular location 32

33. Focal nodular hyperplasia (cont.) CT finding provide strong indication Unenhanced CT shows tumor as a hypo dens mass They are common under the liver surface and usually measure <5 cm. On unenhanced CT, they are hypodense to liver and show significant enhancement on arterial phase images and become isodense to liver on portal venous phase images and delayed phase images 33

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36. Hepatic cell adenoma is uncommon tumor that occur in women of child bearing age tendency to hemorrhage is a clinical significance distinguish hepatocellular adenoma from hepatocellular carcinoma is difficult hepatic cell adenomas are well circumscribed, often encapsulated , and usually solitary. 36

37. Hepatic cell adenoma (cont.) Hepatic adenomas are large, measuring 5–10 cm, and is well-defined On unenhanced CT, they are hypodense , but lesions with hemorrhage appear hyperdense or heterogeneous. On contrast study, these lesions show significant enhancement on arterial phase images as they are supplied by the hepatic artery 37

38. Contrast-enhanced CT scan. A: adenoma; Cy: cyst; C: calcifications within the cystic lesion (arterial phase) 38

39. Malignant Neoplasms Primary Malignant tumors : HCC Cholangiocarcinoma Secondary Malignant tumors (metastasis) 39

40. Hepatocellular Carcinoma=HCC The most common primary malignant tumor of liver representing more than 80% of all primary malignancies It is more in patients with cirrhosis or hemochromatosis, hepatitis B Tendency toward intravascular growth into the hepatic vein & portal system The usual angiographic appearance= a hyper vascular mass being supplied an enlarged hepatic artery 40

41. HCC in CT Scan Most frequently HCC appears as either solitary or multiple discrete hepatic mass On non-contrast- enhanced images , HCC most often appears hypo dens compared to normal liver parenchyma , but up to 12% may be isodens 41

42. Cholangiocarcinoma It can arise from the intrahepatic bile ducts and present as a parenchymal liver mass It can occur as focal masses or as diffuse or multifocal masses It is generally of lower attenuation than liver parenchyma on non-contrast and contrast- enhanced images 42

43. Metastasis They are the most common malignant tumors of the liver They are usually from stomach , colon , pancreas , lungs or breast They are usually multiple with different size One recent study showed that 1/3 of all patient with proven liver metastasis had normal liver function tests , 2/3 of patient with feeling of heavy in Epigastria reign and in physical exam 43

44. Metastasis (Cont.) The margins of the lesion very from sharp and well defined to ill defined and infiltrating . many metastasis show peripheral enhancement around a hypo dense lesion which can be confused with an hemangioma . Most metastatic lesions are hypo vascular and thus appear hypo dense to adjacent enhanced liver parenchyma 44

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46. Fatty infiltration The amount of fat present within the liver isn’t more than 5% of the total weight of organ Excessive deposition of fat in the liver called fatty infiltration It may have a diffuse,regional or focal distribution It causes diminution of the density of hepatic parenchyma 46

47. Fatty infiltration (cont.) Causes : Alcohol Metabolic syndrome (diabetes , hypertension ,obesity ) Nutritional Drug & toxics (tetracycline ,…) Symptoms: Typically this disease have no symptom Sometime : vague , discomfort in the liver region , fatigue On CT image : liver have an attenuation less than spleen 47

48. Fatty liver & normal liver vs. spleen Normal liver Fatty liver 48

49. Cirrhosis Wide-spread proliferation of fibrotic connective tissue Alteration of lobular architecture & modularity of hepatic parenchyma shrinkage On CT image: Increasing the attenuation of liver parenchyma Focal atrophy , fibrosis & regenerating nodules Enlargement of the caudate lobe & lateral segment of left lobe Shrinkage of right lobe 49

50. cirrhosis 50

51. 59 yo male with a history of hepatitis C and alcoholism was referred to the Liver Clinic for transplant evaluation. His symptoms included intermittent abdominal bloating from ascites, a persistent epigastric discomfort and one episode of upper GI bleeding. He underwent a CT scan shown cirrhosis 51

52. Cysts occur as isolated hepatic lesions or as component poly cystic disease Often they are small, asymptomatic & unilocular spherical masses CT is enough to confident diagnosis of cysts Have a homogenic density near to water distinguishing simple cysts from other cavity lesions is difficult, but; polycystic liver disease is easy to recognize by CT 52

53. Cysts (cont.) cysts are lined by fluid-secreting epithelium are congenital or of biliary derivation appear with low attenuation (0-10Hu) 53

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55. Liver & spleen cysts 55

56. Abscess Abscesses occurs when bacteria or protozoa destroy hepatic tissue,producing a cavity which fillswith infectious organisms,leukocytes & pus 56

57. Abscess cont. Causes : Benign or malignant biliary obstruction Abdominal infection( e.g appendicitis,diverticulitis ,…) Infection in blood or biliary ducts( e.g streptococcus,klebsiella ,…) Truma & surgery of right upper quadrant Symptom: Fever Right upper quadrant pain Jaundice Loss of appetite Weakness 57

58. This 74 year-old female presented with right upper quadrant pain and fever. CT demonstrates a large irregular fluid-density lesion within the right lobe of the liver with rim enhancement. There are multiple smaller peripheral lesions with similar characteristics. Some of these appear coalescent. This is the typical appearance for a pyogenic liver abscess. 58

59. Self exam fatty liver 59

60. Spiral & multi slice Computed tomography of the body ( by M. Galanski & other) Protocols for Multi slice CT ( by R.Bruening & Other) MDCT from protocol to practice ( by M.K.Karla & other) Clinical CT techniques & practice ( by S. Henwood ) CT teaching manual ( by M. Hofer) Diagnostic imaging ( by P. Armstrong) Principles & techniques of spiral & multislice CT ( by J.Izadi ) MDCT Anatomy-Body (by L. Romano & other) To get more information see : 60

61. Thanks for your attention 61