Nonpathological focal enhancements on spiral CT hepatic angiography

Kanematsu, Masayuki; Hoshi, Hiroaki; Imaeda, T; Yamawaki, Y; Mizuno, Shinji; Manabe, Tomoko; Enya, Mayumi; Yokoyama, Ryuichi

doi:10.1007/s002619900140

Cited by 24 publications

(13 citation statements)

References 20 publications

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“…The frequency of these nonpathological enhancements seen on HAP or CTA images was significantly higher than that noted in a previous report [41], which is probably due to higher spatial resolution of current CT technology, less partial volume-averaging effects when employing thinner slices, and less respiratory misregistration when using the helical CT scanner [38].…”

Section: Portal Veincontrasting

confidence: 46%

“…This fact explains the observation that these regions match perfectly with the focal nontumoral perfusion defects detected with helical CT during arterial portography (CTAP) [28,30]. The liver parenchyma with aberrant gastric or cystic venous drainage is shown as a hyperattenuating lesion on CTA [38]. On scans of dual-phase helical CT, HAP images may show the involved areas to be hyperattenuating relative to normal liver parenchyma and PVP images show homogeneous enhancement [8].…”

Section: Portal Veinmentioning

confidence: 73%

“…We believe that nontumorous arterioportal shunts are closely related to nontumorous subcapsular wedge-shaped defects on CTAP, which are occasionally seen in the cirrhotic liver [30, 39, 80 -82], because focal increase in portal venous pressure caused by the small arterioportal shunt can produce wedge-shaped defects on CTAP. We also think that these lesions are one of the causes of nontumorous subsegmental enhancements on CTA [38,41].…”

Section: Nontumorous Arterioportal Shunt In Liver Cirrhosismentioning

confidence: 96%

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Hepatic abnormalities related to blood flow: evaluation with dual-phase helical CT

et al. 1999

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Dual-phase contrast-enhanced helical computed tomography (CT) has become a popular technique for the detection and characterization of hepatic lesions [1][2][3][4][5][6][7]. In addition to improved detection of small hypervascular lesions, dual-phase helical CT can provide useful information for the differential diagnosis of various liver lesions by showing contrast enhancement features on scans obtained during the hepatic arterial (more precisely, arterial-dominant) phase (HAP) and the portal venous phase (PVP). Furthermore, careful analysis of the patterns of contrast enhancement at both the HAP and PVP of dualphase helical CT is helpful in the evaluation of hepatic hemodynamic alterations [6,7]. Therefore, at many institutions including ours, dual-phase helical CT is routinely performed for the evaluation of all hepatic lesions [5][6][7][8].Hepatic abnormalities related to blood flow include normal vascular anatomic variants; vascular obstructions such as portal venous obstruction, hepatic venous obstruction, hepatic arterial obstruction, and mediastinal or thoracic venous obstruction; focal liver lesions such as arterioportal shunt, hypervascular tumor, and inflammatory processes; and uncertain etiologies [8 -10].The use of helical CT is apparently increasing the chances of encountering these abnormalities in daily practice, and the importance of knowledge of the hemodynamics of hepatic blood flow has been increasing. Thus, familiarity with the helical CT appearances of different types of hepatic abnormalities related to blood flow allows the radiologist to separate clinically insignificant flow phenomena from perfusion disorders caused by underlying parenchymal or vascular disease.In this article, we discuss how hepatic blood flow can affect the appearance of hepatic abnormalities on dualphase helical CT scans. Physiology of hepatic blood flowThe liver has a dual supply of the portal vein and hepatic artery. The hepatic artery delivers about 20 -25% of blood to the liver, whereas the portal vein delivers about 75-80% [8]. These two hepatic vessels have mutual communication systems including transvasal and transplexal routes [10]. Among them, the most prominent route is transplexal via peribiliary plexus.These routes play an important role when hepatic vessels are compromised. Therefore, knowledge of mutual communication systems of hepatic vessels is essential to understand the pathophysiology and hemodynamics of hepatic abnormalities related to blood flow (Fig. 1). Dual-phase helical CT techniquesWith the advent of helical CT technology, it has become possible to image the liver during the HAP and PVP of enhancement after a single bolus infusion of iodinated contrast material. This dual-phase helical technique is ideally suited to imaging the liver, which is unique among abdominal organs by virtue of its dual blood supply [5,7]. Helical CT images are obtained during a 20 -30-s breath-holding. Scan parameters are collimation, 5-10 mm; pitch, 1-1.5; 120 -140 kV; 150 -290 mA; and rotation time, 0.75-1 s. Images...

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Section: Portal Veincontrasting

confidence: 46%

Section: Portal Veinmentioning

confidence: 73%

Section: Nontumorous Arterioportal Shunt In Liver Cirrhosismentioning

confidence: 96%

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Hepatic abnormalities related to blood flow: evaluation with dual-phase helical CT

et al. 1999

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“…Causes for the false-positive diagnosis of hepatic tumor based on CTHA and CTAP studies reported thus far include cystic venous drainage [1,8,10], aberrant gastric venous drainage [7], anatomically normal (inferior vein of Sappey) or abnormal portosystemic venous communication [11][12][13][14][15], small arterioportal venous shunts [15], compensatory increase and/or congestion in hepatic arterial flow due to portal or hepatic venous flow stoppage [1,16], and other miscellaneous factors. Findings that increase the suspicion for a pseudolesion include atypical Fig.…”

Section: Discussionmentioning

confidence: 99%

“…5), or localization in sites with a high propensity for pseudolesions. Combining CTHA with CTAP generally helps to increase the specificity that would be obtained with CTAP alone [10,13,[17][18][19][20]. Kanematsu et al reported nonpathological focal enhancement on helical CTHA in 31 patients suspected of having liver tumors and analyzed the frequency, size, shape, and relationship with findings on CTAP [10].…”

Section: Figmentioning

confidence: 98%

Focal attenuation differences in pericystic liver tissue as seen on CT hepatic arteriography and CT arterial portography: observation using a unified helical CT and angiography system

et al. 1999

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Small hypervascular hepatocellular carcinoma versus hypervascular pseudolesions: differential diagnosis on MRI

et al. 2002

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Nonpathological focal enhancements on spiral CT hepatic angiography

Abstract: In nearly half of patients, spiral CTA shows various shapes of small nonpathological focal enhancements more frequently in the liver edge.

Cited by 24 publications

References 20 publications

Hepatic abnormalities related to blood flow: evaluation with dual-phase helical CT

Hepatic abnormalities related to blood flow: evaluation with dual-phase helical CT

Focal attenuation differences in pericystic liver tissue as seen on CT hepatic arteriography and CT arterial portography: observation using a unified helical CT and angiography system

Small hypervascular hepatocellular carcinoma versus hypervascular pseudolesions: differential diagnosis on MRI

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