Publications by authors named "Hiroko Naganuma"

Contrast-enhanced sonography (CEUS) is a very important diagnostic imaging tool in clinical settings. However, it is associated with possible artifacts, such as B-mode US-related artifacts. Sufficient knowledge of US physics and these artifacts is indispensable to avoid the misinterpretation of CEUS images.

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Hepatocellular carcinoma (HCC) in a non-fibrotic liver (F0) is considered to be rare, and there is a marked paucity of studies in the literature on this HCC type. A review of the literature shows some important clinical and tumor characteristics: (a) it occurs mainly in young female and elder male patients; (b) clinically, under normal hepatic function, alpha-fetoprotein level is often normal, and there are no risk factors; (c) associated with metabolic disease; (d) macroscopically, single large lesions are noted; and (e) microscopically, the lesions are well-differentiated and encapsulated. Radiological imaging results are straightforward, showing arterial hyperenhancement and later wash-out.

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Shear wave elastography (SWE) is now becoming an indispensable diagnostic tool in the routine examination of liver diseases. In particular, accuracy is required for shear wave propagation velocity measurement, which is directly related to diagnostic accuracy. It is generally accepted that the liver shear wave propagation velocity reflects the degree of fibrosis, but there are still few reports on other factors that increase the shear wave propagation velocity.

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Despite its proven high utility, integration of pocked-sized portable ultrasound (US) into internal medicine residency training remains inconsistent. For 10 years, we have held a 1-d seminar biannually, consisting of lecture (half-day) and hands-on training (half-day) on pocket-sized US of the abdomen and lungs. The lecture consists of training on US physics and clinical applications of pocket-sized US, followed by a lecture covering the basic anatomy of the abdomen and lungs and introducing the systemic scanning method.

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Ultrasonography (US) is the first-line diagnostic tool for observing the whole abdomen. Unfortunately, a wide spectrum of refraction-related artefactual images is very frequently encountered in routine US examinations. In addition, most practitioners currently perform abdominal US examinations without sufficient knowledge of refraction artifacts (RAs).

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Two-dimensional shear wave elastography (2D-SWE) is used in the clinical setting for observation of the liver. Unfortunately, a wide spectrum of artifactual images are frequently encountered in 2D-SWE, the precise mechanisms of which remain incompletely understood. This review was designed to present many of the artifactual images seen in 2D-SWE of the liver and to analyze them by computer simulation models that support clinical observations.

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Introduction: Hereditary hemorrhagic telangiectasia (HHT) is a multiorgan genetic angiodysplastic affection characterized by visceral vascular malformations. It affects mainly the brains, lungs, gastrointestinal tract, and nasal mucosa. Unlike those organs, hepatic involvement, although very frequently occurring, is insufficiently recognized, mainly because of the complex vascular structure of this organ.

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Range-ambiguity artifacts (RAAs) are an erroneous mapping of returning echoes into a composite picture. The purpose of this review was to illustrate the mechanism of RAAs and to present the diagnostic problems caused by RAAs. RAA features differ slightly from organ to organ.

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Purpose: Hepatocellular carcinoma (HCC) on normal liver is very rare. The goal of this study was to determine the clinical manifestations and the role of ultrasonography (US) in the diagnosis of HCC arising in normal liver.

Methods: The clinical data and US findings in 12 cases of surgically resected HCC in normal liver were retrospectively analyzed.

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We present three cases of chronic hepatic porphyria (CHP) in alcoholic patients, in which grayscale ultrasound (US) revealed multiple echogenic masses in the liver, mimicking multinodular hepatocellular carcinoma on alcoholic liver injury. In all cases, contrast-enhanced US (CEUS) showed iso-enhancement of the mass lesions throughout all vascular phases. Additionally, two-dimensional shear wave elastography (2DSWE) (performed in two cases) revealed the mass to have almost the same SWE value as the surrounding parenchyma.

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Splenic artery pseudoaneurysm (SAPA) is a relatively infrequently encountered but clinically important vascular change, because it carries a high risk of rupture that warrants prompt treatment regardless of its size. Thus, sufficient knowledge is indispensable when seeing chronic pancreatitis patients or post-traumatic patients. Here, we report two such cases.

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Lymphangioma of the mesocolon is very rare. We report two cases of surgically resected and histologically proven mesocolic lymphangioma in adults. In both cases, ultrasound revealed a large cystic mass with multiple thin septa in the lower abdomen.

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Focal nodular hyperplasia (FNH) is the second most common benign tumor of the liver, and diagnosis and follow-up without invasive procedures are now highly recommended. FNH shows a characteristic vascular structure called "spoke-wheel appearance". However, this appearance relies on the mode of the feeding artery, and the mode of the draining vein has not been sufficiently studied until recently.

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Purpose: Contrast-enhanced ultrasound (CEUS) is a very sensitive diagnostic tool in characterizing liver tumors. It is especially useful in the diagnosis of focal nodular hyperplasia (FNH) of the liver. According to the previous reports, FNH is common in young women, and it is usually diagnosed by MRI.

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