The cranial abdomen: Liver and Spleen

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Anastasia Reed
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1 The cranial abdomen: Liver and Spleen Tony Pease, DVM, MS Assistant Professor of Radiology North Carolina State University Reading Chapter 41 in Thrall Imaging the cranial abdomen Thickest part of the body Difficult to get enough contrast Place thickest part of the patient towards the cathode Heel effect 1

2 Cranial abdomen Multiple structures Liver Spleen Stomach Pancreas Small intestine Transverse colon Other modalities MRI CT Ultrasound 2

3 Liver Just caudal to the diaphragm Cranial to the stomach Liver size influences gastric axis Gastric axis Liver or Spleen? LIVER! If it extends cranial to the antrum of the stomach 3

4 Hepatomegaly Rounding of the liver margin Extends well beyond the costal arch Caudodorsal shift of the gastric axis Causes for hepatomegaly Hepatic venous congestion Neoplasia (lymphoma) Hyperadrenocorticism Steroid hepatopathy Diabetes mellitus Hepatic lipidosis Acute hepatitis 4

5 Radiographs Since radiographs just give shape Hard to narrow differentials Need other modalities Ultrasound CT or MRI becoming more available Focal hepatomegaly Neoplasia Abscess Cyst Biloma Liver lobe torsion (rare) Focal Liver mass 5

6 Biliary carcinoma Small liver Hard to define Upright gastric axis Difficult to evaluate with ultrasound Lungs get in the way 6

7 Differential diagnoses Chronic liver disease Cirrhosis Hepatitis Portosystemic shunt Diaphragmatic hernia Portosystemic shunt Abnormal communication Portal vein or tributary Caudal vena cava or azygous vein Multiple ways to detect Contrast medium portography 7

8 Extrahepatic portosystemic shunt Pros and Cons Good visualization Hepatic vasculature Invasive Surgical approach Contrast medium Complications Time Hypothermia Catheter removal Nuclear medicine Gold standard Administer radioisotope per rectum 99 m technetium pertechnetate Enters colic vein to portal vein Yes or no, but no anatomic data Surgeons cannot use as a guide 8

9 Normal scintigram Portosystemic shunt Nothings perfect Microvasculature dysplasia No gross vessel problem Defect is at the capillary level Looks like normal scintigram 9

10 Ultrasound Can be % accurate Is operator dependant Patients usually quite small Patients usually do not like process Normal ultrasound appearance Normal ultrasound appearance 10

11 Intrahepatic portosystemic shunt Other findings Computed tomography Still requires contrast medium Usually debilitated patients Less time with helical scanners Can do 3D reconstruction 11

12 Normal Portal Anatomy Extrahepatic Portosystemic Shunt Extrahepatic Portosystemic Shunt 12

13 MRI No contrast needed Can do a Time of Flight Allows blood to be its own contrast! Moderate amount of time Depends on magnet MRI splenocaval shunt Gall Bladder Look for stones or mineral Can see with radiography or ultrasound Difficult to tell if important Ultrasound can help Especially with cholecystitis 13

14 Intrahepatic cholelithasis Cholelithasis Cholecystitis Generally radiographs not helpful Ultrasound helps more 14

15 The spleen Generally surrounded by fat Very clear on radiography Sedation can increase spleen size Dog spleen Cat spleen 15

16 Spleen Not many things happen to spleen Separate into diffuse and focal disease Radiographs give an idea Ultrasound more helpful for seeing small lesions within parenchyma Diffuse spleen enlargement Neoplasia Lymphoma Mast cell disease Congestion Sedation Right heart failure Splenic torsion IMHA Inflammation Infarction Nodular hyperplasia Extramedullary hematopoesis Splenic torsion 16

17 Splenic torsion Splenic lymphoma Splenic lymphoma 17

18 Solitary splenic mass Neoplasia Hemangiosarcoma Hemangioma Nodular hyperplasia Hematoma Abscess Splenic mass Splenic mass 18

19 Conclusion Liver is cranial to the stomach Spleen is just caudal Radiographs outline organ Cross sectional modalities Ultrasound, CT and MRI Nuclear medicine Portosystemic shunts 19

Geir Folvik, MD Division of Gastroenterology Department of Medicine, Haukeland University Hospital Bergen, Norway 30.11.2015

Benign liver diseases Geir Folvik, MD Division of Gastroenterology Department of Medicine, Haukeland University Hospital Bergen, Norway 30.11.2015 1 Agenda Benign focal liver lesions Fatty liver disease