Hepatic hemangiomas with arterioportal shunt: findings at two-phase CT

Capability of multidetector CT to diagnose hepatocellular carcinoma-associated arterioportal shunt

AIM: To investigate the capability of multidetector CT (MDCT) to diagnose HCC-associated arterioportal shunt (APS).

METHODS: Two hundred and eighty-two patients with HCC received both thin-slice and enhancement MDCT scanning at early hepatic arterial phase, late hepatic arterial phase and portal venous phase, and digital subtract angiography (DSA) examination. Images were analyzed jointly by two experienced radiologists blinded to the opposite examination results, including the existence or not of APS, shunt locations, types and degrees of APS, with or without thrombosis.

RESULTS: There were 56 APS associated with HCC, including 48 central, seven peripheral and one mixed, or 42 severe, seven moderate, seven mild APS. Forty-one severe, seven moderate and central APS were all revealed with MDCT and DSA. Seven mild and peripheral APS were all displayed with MDCT; only five of them displayed DSA, two faint shunt APS associated with massive HCC were missed. One mixed APS was demonstrated as severe combined with mild shunt with both MDCT and DSA.

CONCLUSION: MDCT could diagnose not only DSA revealed APS, but also missed mild and peripheral APS with DSA due to faint shunt associated with massive HCC, is a simple, effective and noninvasive new technique for diagnosis of HCC-associated APS.

Imaging diagnosis of hepatocellular carcinoma with differentiation from other pathology

Recent advances in liver imaging techniques and better understanding of imaging findings have facilitated the detection and characterization of hepatocellular nodules in a cirrhotic liver. It is important to recognize that various types of benign nodules and pseudolesions are identified on all imaging scans performed for the diagnosis of hepatocellular carcinoma. An accurate differentiation between them is critical for adequate management of cirrhotic patients. Unfortunately, any of the imaging tests and even percutaneous biopsy are not diagnostic for borderline lesions. Intimate collaboration of hepatologists, pathologists, surgeons, and radiologists with reasonable imaging and clinical criteria estimating the degree of malignancy is imperative.

Peritumoral fat-spared area is well correlated with the presence of temporal peritumoral enhancement in hepatic hemangioma in fatty liver

PURPOSE

To assess the relationship between temporal peritumoral enhancement and peritumoral focal fat sparing adjacent to hepatic hemangiomas.

MATERIALS AND METHODS

On the basis of MRI and sonographic imaging follow-up, 51 hepatic hemangiomas were identified in 37 patients, who had both hepatic hemangiomas and focal fat-sparing areas in fatty liver. Among them, 36 tumors were associated with peritumoral focal fat spares. The association between the temporal peritumoral enhancement in the early arterial phase of dynamic MRI and peritumoral fat sparing in the same hemangioma was investigated. Furthermore, the configuration of the temporal peritumoral enhancement was correlated with that of the peritumoral focal fat-sparing area. We used Chi square and Fisher's exact test for statistic analysis.

RESULTS

A total of 31 out of 36 hemangiomas (86.1%) showed both peritumoral focal fat spares and temporal peritumoral enhancement. The presence of temporal peritumoral enhancement is significantly related to that of peritumoral focal fat-sparing (P < 0.001). A total of 21 of the 31 tumors (67.7%) presented with similar configuration of the peritumoral focal fat-sparing area and temporal peritumoral enhancement area with respect to size and shape. The remaining 10 hemangiomas showed similar shape but slightly different size in these two imaging characteristics.

CONCLUSION

Temporal peritumoral enhancement seen in hepatic hemangioma might be related to focal fatty sparing adjacent to the hemangiomas.

Arterioportal shunt: prevalence in small hemangiomas versus that in hepatocellular carcinomas 3 cm or smaller at two-phase helical CT

PURPOSE

To compare the prevalence of arterioportal (AP) shunting associated with (a) small (< or =3 cm) hemangiomas and (b) hepatocellular carcinomas (HCCs) (< or =3 cm) at two-phase helical computed tomography (CT).

MATERIALS AND METHODS

Two-phase helical liver CT was performed in 107 patients (61 men, 46 women; age range, 25-73 years; mean, 48.6 years) with 169 small hemangiomas and in 384 patients (292 men, 92 women; age range, 18-82 years; mean, 58.3 years) with 598 HCCs 3 cm or smaller. Diagnosis of HCC was verified with histologic findings (n = 30) or typical imaging and clinical findings (n = 568); that of all hemangiomas was verified with typical imaging and clinical findings. Three radiologists retrospectively reviewed all CT images in consensus. Contrast material-enhanced CT scans were obtained during the hepatic arterial and portal venous phases. AP shunt was considered to be present when wedge-shaped or irregularly shaped homogeneous enhancement peripheral to tumor appeared at hepatic arterial phase CT and isoattenuation or slight hyperattenuation in that area appeared at portal phase CT. The prevalence of AP shunting associated with hemangiomas and that associated with HCCs were compared with multivariate model testing. Speed of lesion enhancement (rapid enhancement, when extent of intratumoral enhancement at hepatic arterial phase CT was >50%; slow enhancement, when extent of intratumoral enhancement was < or =50%) and presence of AP shunt were correlated with chi2 or Fisher exact testing.

RESULTS

AP shunts were more frequently found in hemangiomas (36 lesions [21.3%]) than in HCCs (25 lesions [4.2%]) (P <.001). Twenty-four (38%) of the 64 hemangiomas with rapid enhancement had AP shunts, whereas only 12 (11.4%) of the 105 hemangiomas with slow enhancement had AP shunts (P <.001). There was no significant difference between prevalence of AP shunt in the 573 HCCs with rapid enhancement (24 lesions, 4.2%) and that in the 25 HCCs with slow enhancement (one lesion, 4.0%).

CONCLUSION

AP shunts were more frequently seen at two-phase helical CT in small hepatic hemangiomas than in HCCs and thus represent a suggestive but not specific finding of hemangioma. Small hemangiomas with AP shunts tend to show rapid rather than slow enhancement.

N/A

N/A

Study on hepatocelluar carcinoma-associated hepatic arteriovenous shunt using multidetector CT

AIM: To investigate multidetector CT (MDCT) findings of hepatocelluar carcinoma (HCC)- associated hepatic arteriovenous shunt (HAVS) and to evaluate their clinical significance.

METHODS: Thin-slice and dynamic enhancement MDCT of HAVS was performed on 56 patients with HCC. MDCT findings, including those of portal veins, hepatic veins, superior mesenteric veins, splenic veins, HCC foci, liver parenchyma without HCC foci, spleens, and thromboses in portal veins and hepatic veins, were all confirmed by digital subtract angiography and analyzed.

RESULTS: MDCT demonstrated earlier enhancement of main portal trunks and/or the first order branches than that of superior mesenteric veins or splenic veins (n = 31). One patient had strong early enhancement of left hepatic vein with thromboses in left hepatic vein and upper part of inferior vena cava and 1 patient had transient patchy enhancement peripheral to HCC foci in late hepatic arterial phase among them. It demonstrated stronger opacification of main portal trunks and/or the first order branches than that of superior mesenteric veins or splenic veins (n = 18), and earlier enhancement of the second order and smaller branches of portal veins than that of main portal trunks (n = 4), stronger opacification of the second order and smaller branches of portal veins than that of main portal trunks (n = 3), with transient patchy enhancement (n = 3) or wedge-shaped enhancement (n = 4) peripheral to HCC foci in late hepatic arterial phase. Enhancement degree of HCC foci was all decreased. As for 49 patients with severe or moderate shunts, enhancement degree of liver parenchyma without HCC foci was increased with heterogeneous density, but enhancement degree of spleens was decreased. There were thromboses in main portal trunks and/or the first order branches in 32 patients.

CONCLUSION: The main MDCT findings of HCC-associated HAVS are earlier enhancement and stronger opacification of portal veins and/or hepatic veins. Understanding of these findings will contribute to the diagnosis and prognosis of the disease and improve therapy for the patients.

Temporal Peritumoral Enhancement of Hepatic Cavernous Hemangioma

OBJECTIVE

To evaluate the occurrence rate of temporal peritumoral enhancement associated with hepatic cavernous hemangiomas and to correlate that with the speed of intratumoral contrast enhancement and tumor volume.

METHODS

Dynamic magnetic resonance imaging (MRI) of 69 consecutive patients with 136 hemangiomas was reviewed for peritumoral enhancement. Tumor volume was estimated by the largest diameter on T2-weighted images. Speed of intratumoral contrast enhancement was determined by portal phase image and was categorized as rapid (>75% of tumor volume), intermediate (25%-75% of tumor volume), or slow (<25% of tumor volume).

RESULTS

Temporal peritumoral enhancement was found in 37 (26.6%) of 136 hemangiomas. It was more common in hemangiomas with rapid enhancement (30 of 67 cases [44.8%]) than in those with intermediate (3 of 22 cases [13.6%]) and slow (4 of 47 cases [8.5%]) enhancement (P < 0.05). There was no statistically significant relation between lesion size and presence of temporal peritumoral enhancement (P > 0.05).

CONCLUSIONS

Temporal peritumoral enhancement is not uncommonly seen in hepatic cavernous hemangiomas at dynamic MRI. It is most commonly encountered in rapidly enhancing small lesions. There is no statistically significant relation between temporal peritumoral enhancement and tumor volume, however.

Arterioportal shunts mimicking hepatic tumors with hyperintensity on T2-weighted MR images

We report and assess the imaging findings in a patient with multiple arterioportal shunting mimicking multiple hypervascular tumors that showed multiple areas of hyperintensity with gadolinium-enhanced gradient-recalled-echo images obtained in the hepatic arterial phase and corresponding areas of slight hyperintensity with T2-weighted images.

Hepatic arterioportal shunts: dynamic CT and MR features

With the increased temporal resolution available in dynamic computed tomography (CT) and magnetic resonance imaging (MRI), hepatic arterioportal shunts are now more frequently encountered than in the past. The condition occurs in various hepatic diseases in which portal or hepatic venous flow is compromised. The underlying mechanism and the degree of shunt affect its appearance at dynamic imaging. The dynamic CT and MRI findings have been summarized as early enhancement of peripheral portal veins, and wedge-shaped transient parenchymal enhancement during the hepatic arterial phase. Recognition of arterioportal shunt can suggest the presence of a previously unsuspected disorder and avoids false-positive diagnosis or overestimation of a hepatic disease. Familiarity with the pathophysiology of arterioportal shunt also allows investigation of the hepatic hemodynamic changes occurring in various hepatic diseases.