Abdominal imaging findings in adult patients with Fontan circulation

Abstract

The Fontan procedures, designed to treat paediatric patients with functional single ventricles, have markedly improved the patient's survival into adulthood. The physiology of the Fontan circuit inevitably increases systemic venous pressure, which may lead to multi-system organ failure in the long-term follow-up. Fontan-associated liver disease (FALD) can progress to liver cirrhosis with signs of portal hypertension. Focal nodular hyperplasia-like nodules commonly develop in FALD. Imaging surveillance is often performed to monitor the progression of FALD and to detect hepatocellular carcinoma, which infrequently develops in FALD. Other abdominal abnormalities in post-Fontan patients include protein losing enteropathy and pheochromocytoma/paraganglioma. Given that these abdominal abnormalities are critical for patient management, it is important for radiologists to become familiar with the abdominal abnormalities that are common in post-Fontan patients on cross-sectional imaging.

Teaching points: • Fontan procedure for functional single ventricle has improved patient survival into adulthood. • Radiologists should be familiar with unique imaging findings of Fontan-associated liver disease. • Focal nodular hyperplasia-like nodules commonly develop in Fontan-associated liver disease. • Hepatocellular carcinoma, protein-losing enteropathy, pheochromocytoma/paraganglioma may develop.

Keywords: Diagnostic imaging; Digestive system neoplasms; Focal nodular hyperplasia; Heart defects, congenital; Liver cirrhosis.

Fig. 1

Hepatic parenchymal change in US in post-Fontan patients. a A 33-year-old woman with previous pulmonary atresia. US reveals heterogeneous parenchymal echotexture with central zone hyper-echogenicity and peripheral zone hypo-echogenicity (arrows). b-d A 30-year-old woman with previous hypoplastic right ventricle syndrome. b US shows irregular homogeneous hyperechoic mass-like areas (arrowheads) surrounding portal vein branches with geographic margin. c, d In-phase and opposed-phase axial T1-weighted MRI demonstrates increased signal intensity (SI) on in-phase image (c) and dropped SI on opposed-phase image (d), suggesting fat deposit (dotted arrows). These areas correspond to the hyperechoic mass-like areas on US. e A 48-year-old woman with previous double outlet right ventricle. Contrast-enhanced ultrasound image obtained at 3 min shows marked coarse and heterogeneously weak delayed parenchymal enhancement

Fig. 2

Hepatic parenchymal change in CT and MRI in post-Fontan patients. a A 22-year-old woman with previous right atrial isomerism and pulmonary atresia. Axial CT image in portal venous phase demonstrates reticular regions of poor parenchymal enhancement in the periphery of the liver, which are prominent in the portal venous phase. Note that the stomach is located on the right side (asterisk) with left-sided liver and inferior vena cava (heterotoxy syndrome). b A 36-year-old woman with previous hypoplastic right ventricle syndrome. Axial CT image in portal venous phase demonstrates diffuse ill-defined inhomogeneous enhancement in the liver. Note that the caudate lobe hypertrophy with relative homogeneous attenuation (arrows). c-e A 22-year-old woman with previous hypoplastic right ventricle syndrome. Axial contrast-enhanced T1-weighted MR images with gadoxetate disodium–enhanced MR images obtained in the arterial phase (c), transitional phase (d) and hepatobiliary phase (e). c Multiple small arterial-enhancing foci (dotted arrows) with contrast agent retention in the hepatobiliary phase are scattered in the liver, in keeping with focal nodular hyperplasia-like nodules. d The arterial-enhancing foci show no delayed washout. Note that heterogeneous parenchymal enhancement is prominent in the right posterior segment of the liver (arrowheads). e The liver shows heterogeneously mildly decreased contrast material uptake, possibly reflecting decreased hepatic function and congestion. Also, low-signal intensity reticular bands with no contrast material retention (arrows) which may be due to dilated veins / fibrous septa and tend to spare regions around the portal triads while coming into direct contact with hepatic veins

Fig. 3

Focal nodular hyperplasia-like nodules in post-Fontan patients. a-d A 21-year-old woman with previous double inlet left ventricle. a There is an approximately 2.3 cm homogeneous hypervascular nodule in segment 7, periphery of the liver (arrow) on the axial arterial phase post contrast T1-weighted MR image. b The lesion showed iso-signal intensity with no hypointensity on the axial transitional phase post contrast T1-weighted MR image. c The lesion with a few other small foci (dotted arrows) showing increased contrast material uptake in the hepatobiliary phase T1-weighted MR image with gadoxetate disodium. d Single-shot echo-planar diffusion-weighted image (b = 1,000 s/mm²) demonstrates no diffusion restriction in the corresponding lesion

Fig. 4

Hepatocellular carcinoma with extensive tumour thrombus in a post-Fontan patient. A 38-year-old woman with previous right atrial isomerism and pulmonary atresia. a Axial CT image in the portal venous phase demonstrates a 1.1-cm iso-attenuated nodule causing surface contour abnormality in segment 2 of the liver (arrow). This lesion was initially reported as regenerative nodule. b-d On 6-month follow-up MRI, the lesion increased to 3.4 cm, showing arterial enhancement (b), washout in 3-min delay (c), and strong diffusion restriction in single-shot echo-planar diffusion-weighted image (b = 1,000 s/mm²) (d). Biopsy confirmed the lesion as HCC and the lesion was successfully treated with radiofrequency ablation (RFA). e Local recurrence of segment II in the dome HCC directly invaded the inferior vena cava (not shown) and subsequently an extensive tumour thrombus developed and filled the inferior vena cava, the right atrium (asterisks) and extended to the left main pulmonary artery

Fig. 5

Vessel evaluation in post-Fontan patients. a-c A 31-year-old woman with previous pulmonary atresia with intact ventricular septum. a Coronal CT shows indirect diversion of both SVC and IVC to pulmonary arteries via the right atrium (asterisk), corresponding with atriopulmonary anastomosis. b, c Spectral Doppler US examination. b Middle hepatic vein shows preservation of hepatopetal blood flow (arrows). c Right portal vein shows heterogeneously coarse hepatopetal flow. d-f A 21-year-old woman with previous left atrial isomerism with pulmonary atresia. d Coronal CT shows direct diversion of both the SVC and IVC to pulmonary arteries, corresponding with total cavopulmonary anastomosis. Situs inversus is also noted. e, f Spectral Doppler US examination. e Left-side hepatic vein demonstrates disappearance of hepatopetal blood flow. f Right-side portal vein demonstrates relatively homogeneous hepatopetal flow. g-i A 33-year-old woman with previous hypoplastic right ventricle with tricuspid atresia. Coronal (g) and axial (h, i) CT images in the portal venous phases demonstrate intrahepatic venous-venous collateral formation (double-lined arrow in g), enlarged hepatic veins (arrowheads in h), and small main portal vein (dotted arrow in i)

Fig. 5

Vessel evaluation in post-Fontan patients. a-c A 31-year-old woman with previous pulmonary atresia with intact ventricular septum. a Coronal CT shows indirect diversion of both SVC and IVC to pulmonary arteries via the right atrium (asterisk), corresponding with atriopulmonary anastomosis. b, c Spectral Doppler US examination. b Middle hepatic vein shows preservation of hepatopetal blood flow (arrows). c Right portal vein shows heterogeneously coarse hepatopetal flow. d-f A 21-year-old woman with previous left atrial isomerism with pulmonary atresia. d Coronal CT shows direct diversion of both the SVC and IVC to pulmonary arteries, corresponding with total cavopulmonary anastomosis. Situs inversus is also noted. e, f Spectral Doppler US examination. e Left-side hepatic vein demonstrates disappearance of hepatopetal blood flow. f Right-side portal vein demonstrates relatively homogeneous hepatopetal flow. g-i A 33-year-old woman with previous hypoplastic right ventricle with tricuspid atresia. Coronal (g) and axial (h, i) CT images in the portal venous phases demonstrate intrahepatic venous-venous collateral formation (double-lined arrow in g), enlarged hepatic veins (arrowheads in h), and small main portal vein (dotted arrow in i)

Fig. 6

Pheochromocytoma in a post-Fontan patient. A 24-year-old woman with previous hypoplastic right ventricle with dysplastic tricuspid valve. Axial CT images in the arterial (a) and portal venous (b) phases demonstrate a 4.5-cm heterogeneous enhancing mass originating from left adrenal gland (arrows). The patient underwent an operation and the lesion was confirmed as pheochromocytoma. Note numerous arterial enhancing foci with no delayed washout scattered in the liver in the arterial phase and heterogeneous poor parenchymal enhancement in the periphery of the liver in the portal venous phase (arrowheads). Caudate lobe is hypertrophied with relative homogeneous enhancement (asterisk)