State-of-the-art cross-sectional liver imaging: beyond lesion detection and characterization

Figures & data

Figure 1 Diagram of the portal venous anatomy to the liver.

Notes: This is the most common distribution of the portal vein branches. The left portal vein supplies segments 2, 3, and 4. The right portal vein supplies segments 5–8.

Figure 2 Diagram of the arterial anatomy to the liver.

Notes: This is the most common distribution of the arterial supply to the liver. The hepatic artery is seen arising from the celiac artery. The right and left gastric arteries are labeled.

Figure 3 (A) Axial maximum intensity projection image at the level of the celiac artery. The common hepatic (hep.), splenic, and right gastric arteries are identified. (B) Axial “iodine-material” image at the level of the celiac artery. The common hepatic, splenic, and right gastric arteries are identified. (C) Coronal “iodine-material” image at the level of the celiac and superior mesenteric arteries. The common hepatic, left gastric, splenic, and superior mesenteric arteries are identified.

Figure 4 (A) Post-gadolinium magnetic resonance axial images of the abdomen below the level of the celiac artery. The common hepatic (hep.), splenic, and right gastric arteries are identified. (B) Post-gadolinium magnetic resonance coronal maximum intensity projection of the abdomen. The common hepatic and splenic arteries are identified. (C) Post-gadolinium magnetic resonance axial maximum intensity projection of the abdomen. The common hepatic and splenic arteries are identified.

Figure 5 (A) Phase contrast (nongadolinium) magnetic resonance axial images of the abdomen below the level of the celiac artery. The splenic vein (v.) and portal confluence are identified. The bright signal shows normal directional flow of the splenic vein. (B) Post-gadolinium magnetic resonance axial images of the abdomen below the level of the celiac artery. The splenic vein and portal confluence are identified. This corresponds to the anatomy seen in (A).

Figure 6 CTCP with minimum intensity projection.

Notes: Cholangiopancreatography with computed tomography allowing visualization of the biliary and pancreatic duct anatomy. This is a 10 mm coronal oblique reformatted image with minimum intensity projection. The source images are at 2.5 mm during the portal venous phase following administration of intravenous contrast. The image demonstrates the gallbladder (white arrow), the common bile duct (blue arrow), and the right hepatic duct (orange arrow) and pancreatic (green arrow) duct. The minimum intensity increases the contrast of fluid.
Abbreviation: CTCP, computed tomographic cholangiopancreatography.

Figure 7 MRCP.

Notes: MRI acquired in a single breath hold (less than 5 seconds) allowing visualization of biliary and pancreatic duct anatomy. There are gallbladder stones (*) and also a choledochal stone (black arrow). There is dilatation of the biliary ducts. The common bile duct, the right and left hepatic ducts, and the right anterior and right posterior hepatic ducts are depicted. There is a low confluence of the right and left hepatic ducts (white arrow).
Abbreviations: MRCP, magnetic resonance cholangiopancreatography; MRI, magnetic resonance imaging; CBD, common bile duct; LHD, left hepatic duct; RHD, right hepatic duct; RAHD, right anterior hepatic duct; RPHD, right posterior hepatic duct.

Figure 8 MRCP with Gd-EOB-DTPA.

Notes: Magnetic resonance cholangiography acquired in a single breath hold following intravenous administration of Gd-EOB-DTPA (at 20 minutes, 5 mm). (A – D) These are sequential coronal images from anterior to posterior. There has been a prior right hepatectomy. There is normal enhancement of the liver and excretion of contrast into the bile ducts, which represents a functional information that this contrast medium can provide. Hepatocytes need to have normal biliary membrane transports to uptake the contrast media e eliminate it into the biliary tree. There are normal caliber intrahepatic bile ducts (segment II, white arrow) and common bile duct (green arrow). Metastasis in segments II and III are noted (yellow arrow).
Abbreviations: Gd-EOB-DTPA, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid; MRCP, magnetic resonance cholangiopancreatography.

Figure 9 MRCP with Gd-EOB-DTPA.

Notes: Magnetic resonance cholangiography acquired in a single breath hold following intravenous administration of Gd-EOB-DTPA (20 minutes, 5 mm). (A – D) These are sequential coronal images from posterior to anterior. There is a cyst in segment VIII (orange arrow). There is enhancement of the liver, but no contrast in the left bile ducts (white arrow) or common bile duct (green arrow) due to obstruction of the biliary tree by an infiltrating mass with the transition zone at the distal bile duct.
Abbreviations: Gd-EOB-DTPA, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid; MRCP, magnetic resonance cholangiopancreatography.

Figure 10 CT image of fatty liver disease.

Notes: Axial nonenhanced CT image showing the liver (*) with lower attenuation than the vessels (white arrow). A region of interest was placed in the liver and spleen (circles). Attenuation of the liver and spleen was 5 HU and 40 HU, respectively, in keeping with more than 50% fatty liver disease.
Abbreviations: CT, computed tomography; HU, Hounsfield units.

Figure 11 MRI of fatty liver disease.

Notes: Axial T1W in-phase (A) and out-of-phase (B) MRI. There is loss of signal intensity of the liver in the out-of-phase (−) image relative to the in-phase (+) image in keeping with steatosis. (C) Graph demonstrating signal loss on the out-of-phase series. The first bar (1) is the addition of 60% water (green) and 40% fat (blue) signal, resulting in 100% of signal on the in-phase image. The second bar (2) is the superposition of water and fat signal on the out-of-phase sequence (60% and 40%, respectively). The third bar (3) is the net signal from the out-of-phase series (20%), and it represents the subtraction of water (60%) and fat (40%) signal. Another hypothetical case with the opposite composition (40% of water and 60% of fat) will also results in 20% of net signal on the out-of-phase image.
Abbreviations: T1W, T1-weighted; MRI, magnetic resonance image.

Figure 12 MRI of the abdomen with the Dixon technique.

Notes: Axial T1W in-phase (A) and out-of-phase (B) images. The 100% fat images (C) and 100% water images (D) are also acquired with the Dixon technique. All these images are obtained during the same acquisition. Note the homogeneous fat saturation on the 100% water only images (D).
Abbreviations: T1W, T1-weighted; MRI, magnetic resonance image.

Figure 13 CT image showing liver iron overload.

Notes: Axial nonenhanced CT image showing the liver with higher attenuation (*). A region of interest was placed in the liver and spleen green (circles). Attenuation of the liver and spleen were 78 HU and 44 HU, respectively. A hepatic attenuation higher than 71 HU has a specificity of 96% for iron overload. This is in contrast with the fatty liver seen in Figure 10.
Abbreviations: CT, computed tomography; HU, Hounsfield units.

Figure 14 MRI showing iron overload.

Notes: Axial T1W in-phase (A) and out-of-phase (B) images. There is loss of signal intensity in the liver on both images; however, the signal drop is more pronounced on the in-phase (−) image than on the out-of-phase (+) image. This is a result of the longer TE parameter of the former. This results in susceptibility artifact. (C–E) MRI acquisition used for iron quantification. The TE increases from (C) to (E). There is loss of signal intensity of the liver when the TE is increased, and this reduction is proportional to the amount of iron within the hepatic parenchyma. In this case, the iron concentration in the liver was 15 mg/g, in keeping with severe hemochromatosis.
Abbreviations: MRI, magnetic resonance image; T1W, T1-weighted; TE, time of echo.

Figure 15 MRI showing iron overload in the liver and pancreas.

Notes: Axial T1W in-phase image. There is loss of signal intensity of the liver (white arrow) and pancreas (black arrow), while signal intensity in the spleen (*) is preserved. These findings are in keeping with parenchymal iron storage due to primary iron overload (hereditary hemochromatosis).
Abbreviations: MRI, magnetic resonance image; T1W, T1-weighted.

Figure 16 Axial post-contrast CT image in a patient with cirrhosis.

Notes: The right liver (−) is reduced in size, while the lateral left liver segments (+) are increased in volume. There is diffuse heterogeneity of the hepatic parenchyma, nodularity of the liver surface (white arrow), and enlargement of the fissures (white arrowhead). These findings are in keeping with cirrhosis. Findings of portal hypertension are also noted: splenomegaly (*), collateral vessels (dark arrows), reduced portal vein caliber (dark arrowhead), and ascites (a). Residual material from arterial embolization of a small hepatocarcinoma is present in the right liver (curved white arrow).
Abbreviation: CT, computed tomography.

Figure 17 MRIs showing cirrhosis.

Notes: (A) Axial pre-contrast and (B) 20 minutes post-contrast with Gd-EOB-DTPA images of a patient with cirrhosis (Child-Pugh score 9). There is diffuse heterogeneity of the hepatic parenchyma and nodularity of the liver. Enhancement at 20 minutes is barely perceptible. There is also no contrast in the bile ducts. The poor liver function diminishes the value of the hepatocyte phase.
Abbreviations: Gd-EOB-DTPA, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid; MRIs, magnetic resonance images.

Figure 18 MR elastography.

Notes: Axial MR elastogram of the liver. The color corresponds to the propagation of waves on the MR elastogram. There is no significant fibrosis.
Abbreviation: MR, magnetic resonance.

Figure 19 MRIs showing focal fat.

Notes: Axial T1W in-phase (A) and out-of-phase (B) MRIs. There is a focal area (white arrow) of signal loss on the out-of-phase image related to the in-phase image. It has a triangular shape and is located in segment IV adjacent to the porta hepatis. The characteristics and position are compatible with focal steatosis.
Abbreviations: MRIs, magnetic resonance images; T1W, T1-weighted.

Figure 20 MRI showing focal iron.

Notes: Axial porta hepatis in-phase (A) and out-of-phase (B) MRIs. There are many geographic areas of low signal intensity (arrows) scattered within the liver parenchyma. The loss of signal is more pronounced on in-phase image related to out-of-phase image because of the longer time of echo parameter of the former in keeping with focal iron deposits.
Abbreviation: MRI, magnetic resonance image.

Figure 21 Radiation changes in the liver.

Notes: Axial computed tomography (A) of the abdomen for simulation of the external radiation dose to the liver. The red central area in the liver corresponds to the highest dose of radiotherapy. (B) Axial post-Gd-EOB-DTPA magnetic resonance of the liver showing decreased enhancement corresponding to the treated area in (A). The decreased enhancement is due to the effects of external radiation on the liver function.
Abbreviation: Gd-EOB-DTPA, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid.

Figure 22 Liver volumetry.

Notes: Axial computed tomography (A) of the abdomen with intravenous contrast. The lines demonstrate the demarcation between the right and left liver and between the segments in the left liver. (B–F) Volumetry for segments 3, 4, 2, 1, and the whole liver, respectively.