Evaluation of Hemodynamics in Focal Steatosis and Focal Spared Lesion of the Liver Using Contrast-Enhanced Ultrasonography with Sonazoid

Abstract

We aim to investigate the hemodynamics in focal steatosis and focal spared lesion of the liver using contrast-enhanced ultrasonography (CEUS) with Sonazoid. The subjects were 47 patients with focal steatosis and focal spared lesion. We evaluated enhancement patterns (hyperenhancement, isoenhancement, and hypoenhancement) in the vascular phase and the presence or absence of a hypoechoic area in the postvascular phase for these lesions using CEUS. Of the 24 patients with focal steatosis, the enhancement pattern was isoenhancement in 19 and hypoenhancement in 5. Hypoechoic areas were noted in the postvascular phase in 3 patients. Of the 23 patients with focal spared lesions, the enhancement pattern was isoenhancement in 18 and hyperenhancement in 5. No hypoechoic areas were noted in the postvascular phase in any patient. The hemodynamics in focal steatosis and focal spared lesions in nondiffuse fatty liver can be observed using low-invasive procedures in real-time by CEUS. It was suggested that differences in the dynamics of enhancement in the vascular phase of CEUS were influenced by the fat deposits in the target lesion, the surrounding liver parenchyma, and the third inflow.

Contrast‐Enhanced Ultrasound Quantification Assessment of Focal Fatty Variations in Liver Parenchyma

“…An area of FFS was isoenhancing in 78% and hyperenhancing in 22% of cases, with no hypovascularity in the postvascular phase. Even with the use of a different agent (Sonazoid), it was concluded that an area of FFI is usually isoenhancing with the liver parenchyma 21 . Nevertheless, in this study, FFS showed a significantly lower PE compared with the adjacent liver, whereas when assessed qualitatively, most FFS and FFI areas were isoenhancing compared with the liver parenchyma 21 …”

“…Nondiffuse hepatic fat abnormalities can take several different forms: (1) focal steatosis with a single area of FFI; (2) multifocal steatosis in the form of multiple FFI areas; (3) lobar or segmental steatosis; (4) a geographic form; (5) FFS in a background of diffusely fatty liver; and (6) perivascular deposition of fat in hepatic and portal venous branches 3,5,21 . Diffuse fat steatosis is the most commonly seen type of fat deposition and is associated with a number of conditions, including diabetes mellitus, hyperlipidemia, obesity, alcoholic liver disease, and hepatitis B and C, but widespread steatosis of the liver may also be seen in asymptomatic patients 1,3 .…”

Hepatic fat quantification using the two‐point Dixon method and fat color maps based on non‐alcoholic fatty liver disease activity score

“…There is a considerable reason for non‐uniformity of fat distribution in the liver. Normally, hepatic blood supply is from the portal vein and hepatic artery; however, some veins directly enter the liver and these flows are called “third inflow.” Three vessels have been reported to cause third inflow: the right gastric, cholecystic and Sappey's veins . These vessels supply the area of segment IV, around the gallbladder fossa, and Sappey's vein area, which can develop focal fatty or focal spared areas (focal areas of decreased fatty infiltration in a fatty liver), because hormones and nutritional elements in these areas are different from those in other areas of the liver .…”

“…Three vessels have been reported to cause third inflow: the right gastric, cholecystic and Sappey's veins. [24][25][26][27] These vessels supply the area of segment IV, around the gallbladder fossa, and Sappey's vein area, which can develop focal fatty or focal spared areas (focal areas of decreased fatty infiltration in a fatty liver), because hormones and nutritional elements in these areas are different from those in other areas of the liver. 26 Other reasons for non-uniformity of the fat distribution in the liver are unclear; however, we visually identified non-uniform fat distribution in the liver in many cases.…”

Multifocal Nodular Fatty Sparing Mimicking Hepatic Tumors

“…Although the mechanism of this finding is unclear, we suggest that this increased relative enhancement is partly due to baseline hyperintensity on precontrast images, which resulted from paradoxical suppression of fatty signal intensity of the surrounding liver parenchyma [ 9 ]. Additionally, the fatty cells-induced narrowing or exclusion of blood vessels supplying the surrounding fatty parenchyma resulted in relative hyperenhancement of the spared areas, a finding which is rarely seen [ 10 ].…”