Publications by authors named "Hiroko Naganuma"

21 Publications

  • Page 1 of 1

Portal vein gas in a patient with acute cholangitis: report of a case with emphasis on B-flow imaging.

J Med Ultrason (2001) 2022 Jan 22;49(1):107-108. Epub 2021 Nov 22.

Department of Gastroenterology, Akita Kousei Medical Center, Akita City, Japan.

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http://dx.doi.org/10.1007/s10396-021-01167-2DOI Listing
January 2022

One-day seminar for residents for implementing abdominal pocket-sized ultrasound.

World J Methodol 2021 Jul 20;11(4):208-221. Epub 2021 Jul 20.

Department of Gastroenterology, Akita Red Cross Hospital, Akita-City 010-1495, Japan.

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. Given the simple structure of pocket-sized US devices, understanding the basic physics is sufficient yet necessary to operate the pocket-sized US device. It is important to understand the selection of probes, adjustment of B mode gain, adjustment of color gain, and acoustic impedance. Basic comprehension may have a significant positive impact on the overall utilization of pocket-sized US devices. The easiest and most reliable way to observe the whole abdomen and lungs is a combination of transverse, sagittal, and oblique scanning, pursuing the main vascular system from the center to the periphery of the organ in the abdomen and systemic scanning of the pleura. There is usually a marked change in knowledge and attitudes among the program participants, although skill gaps remain among them. We discuss the limitations and problems to this education system as well.
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http://dx.doi.org/10.5662/wjm.v11.i4.208DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8299907PMC
July 2021

Refraction artifact on abdominal sonogram.

J Med Ultrason (2001) 2021 Jul 22;48(3):273-283. Epub 2021 May 22.

GE Healthcare, Tokyo, Japan.

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). This review article was designed to present many representative RA images seen in the clinical setting, with a brief explanation of the mechanism of these images, in certain cases through an analyzed and reconstructed method using computer simulation that supports clinical observations. RAs are encountered not only with B-mode US but also with Doppler US, contrast-enhanced US, and shear wave elastography. RAs change their appearance according to the situation, but they always have a significant effect on detailed interpretation of abdominal US images. Correct diagnosis of abdominal US relies on a deep understanding of each characteristic artifactual finding, which necessitates knowledge of basic US physics. When analyzing mass lesions, computer simulation analysis helps to reveal the global images of RAs around a lesion.
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http://dx.doi.org/10.1007/s10396-021-01097-zDOI Listing
July 2021

Diagnostic problems in two-dimensional shear wave elastography of the liver.

World J Radiol 2020 May;12(5):76-86

Department of Gastroenterology and Hepatology, Nihon University Hospital, Chiyoda 1018309, Tokyo, Japan.

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. Our computer simulations yielded the following suggestions: (1) When performing 2D-SWE in patients with chronic hepatic disease, especially liver cirrhosis, it is recommended to measure shear wave values through the least irregular hepatic surface; (2) The most useful 2D-SWE in patients with focal lesion will detect lesions that are poorly visible on B-mode ultrasound and will differentiate true tumors from pseudo-tumors (., irregular fatty change); and (3) Measurement of shear wave values in the area posterior to a focal lesion must be avoided.
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http://dx.doi.org/10.4329/wjr.v12.i5.76DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7288776PMC
May 2020

Hereditary hemorrhagic telangiectasia: how to efficiently detect hepatic abnormalities using ultrasonography.

J Med Ultrason (2001) 2020 Jul 10;47(3):421-433. Epub 2020 May 10.

Department of Gastroenterology and Hepatology, Nihon University Hospital, Tokyo, Japan.

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. Thus, treating HHT patients requires a solid understanding of these hepatic anomalies. It is especially important for any general clinicians to be able to recognize clinical findings in HHT, which leads to a high suspicion of HHT and have an index of suspicion for liver abnormalities of HHT. For this purpose, keen awareness of clinical as well as hepatic sonographic (US) findings is paramount.

Aim: The aim of this review is to summarize previously reported findings on the hepatic US through a thorough analysis of related articles, and to (a) determine the role of US in the diagnosis of hepatic involvement in HHT patients and (b) propose the most simple and easy way to detect HHT-related abnormalities during routine US examinations.

Conclusion: Hepatic US serves to diagnose the detailed complex hepatic changes typical of HHT, and contributes to increased diagnostic confidence of hepatic changes in HHT patients, with the most simple way not to overlook HHT-related abnormalities being to find hepatic artery dilatation.
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http://dx.doi.org/10.1007/s10396-020-01022-wDOI Listing
July 2020

Range-ambiguity artifact in abdominal ultrasound.

J Med Ultrason (2001) 2019 Jul 19;46(3):317-324. Epub 2019 Mar 19.

Department of Clinical Laboratory, Akita Kousei Medical Hospital, Akita, Japan.

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. At the level of the urinary bladder, RAAs take the form of a cloud-like, ill-demarcated, immobile, echogenic area, and the depth of the echogenic area differs depending on the pulse repetition frequency (PRF). This form is referred to as "static RAA" in this review. There are two key ultrasound characteristics of RAAs at the level of the liver: (a) the depth of RAAs change according to the PRF, and (b) RAAs move in accordance with the cardiac cycle. This form is referred to as "mobile RAA" in this review. At the level of the gallbladder, RAAs take the form of fine echogenic lines in the gallbladder. This phenomenon is actually a combination of two phenomena: a ring-down artifact and RAA. This form is referred to as "complex RAA (searchlight phenomenon)" in this review. The easiest way to reduce RAAs is to change the image depth. Sufficient knowledge of RAAs can prevent misdiagnosis of erroneously displayed returning echoes as real pathologic changes.
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http://dx.doi.org/10.1007/s10396-019-00938-2DOI Listing
July 2019

Hepatocellular carcinoma in otherwise sonographically normal liver.

J Clin Ultrasound 2019 Jul 28;47(6):325-330. Epub 2018 Nov 28.

Department of Clinical Laboratory, Akita Kousei Medical Hospital, Akita, Akita Prefecture, Japan.

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.

Results: The patients were asymptomatic, had no hepatocarcinogenic factor, and hepatic function tests were almost normal in most cases. HCCs were large, encapsulated, and solitary, and there were predominantly well-differentiated or moderately differentiated in most cases. US showed a hypoechoic rim and lateral shadowing, suggestive of peritumoral capsule formation, and on contrast-enhanced US (CEUS), the tumor was hyperenhanced in arterial phase and washed out in postvascular phase, revealing typical HCC findings.

Conclusions: US raises suspicion of HCC by showing lateral shadowing on grayscale ultrasound and hypervascularity on CEUS of the lesion.
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http://dx.doi.org/10.1002/jcu.22677DOI Listing
July 2019

Multinodular fatty change in the liver in three patients with chronic hepatic porphyria: Contribution of sonography to the diagnosis.

J Clin Ultrasound 2019 Mar 30;47(3):165-168. Epub 2018 Oct 30.

Department of Clinical Laboratory, Akita Kousei Medical Hospital, Akita, Japan.

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. When encountering alcoholic patients with multiple echogenic masses in the liver, CHP must be included in the differential diagnosis. CEUS and 2DSWE allow us to increase our diagnostic confidence of CHP.
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http://dx.doi.org/10.1002/jcu.22660DOI Listing
March 2019

Superb microvascular imaging (SMI) findings of splenic artery pseudoaneurysm: a report of two cases.

J Med Ultrason (2001) 2018 Jul 30;45(3):515-523. Epub 2018 Jan 30.

Department of Diagnostic Pathology, Akita Red Cross Hospital, Akita, Japan.

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. The first case was a 52-year-old woman known to have chronic pancreatitis who presented with hematemesis and hemodynamic instability in which X-ray computed tomography (CT) and color Doppler sonography (CDS) had difficulty visualizing slow blood flow in SAPA, but superb microvascular imaging (SMI) clearly demonstrated the slow blood flow in SAPA, prompting our therapeutic decision to perform rapid embolization. The second case was a 51-year-old woman with post-traumatic SAPA in which 3D SMI enabled us to understand more clearly the topographic relationship between multiple SAPAs as compared with conventional US, leading to a decision to provide immediate surgical treatment. SMI was thought to provide a new insight into the US diagnosis of SAPA. When examining patients suspected of having a SAPA, SMI is an indispensable diagnostic tool at present.
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http://dx.doi.org/10.1007/s10396-018-0858-1DOI Listing
July 2018

Sonographic findings in two cases of lymphangioma of the mesocolon in adults.

J Clin Ultrasound 2018 Jan 25;46(1):78-81. Epub 2017 Apr 25.

Department of Radiology, Akita Red Cross Hospital, 222-1 Kamikitade Saruta, Akita-shi, Akita, 010-1495, Japan.

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. A peculiar finding was the large craniocaudal sliding movement of the mass synchronized with the patient's respiration, which was a clue to the diagnosis of mesenteric lymphangioma. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 46:78-81, 2018.
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http://dx.doi.org/10.1002/jcu.22488DOI Listing
January 2018

Visualization of draining vein in focal nodular hyperplasia by superb microvascular imaging: report of two cases.

J Med Ultrason (2001) 2017 Oct 21;44(4):323-328. Epub 2017 Feb 21.

Department of Gastroenterology, Yamagata Prefectural Central Hospital, Yamagata, Japan.

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. Superb microvascular imaging (SMI) is a new Doppler technology designed to improve visualization of the blood flow, especially slow flow signals from fine vessels, using a new algorithm. Thus, we can expect to see an improvement in visualization of fine vessels in FNH using SMI. Here, we present two cases in which SMI clearly demonstrated not only the typical spoke-wheel appearance but also draining to the hepatic veins. Our observation is believed to be noteworthy in the diagnosis of FNH. In conclusion, we have reported two cases of hepatic FNH in which SMI revealed clearly not only its feeding vessels and intratumoral vasculature but also its draining vessels communicating with the hepatic vein. SMI is considered to increase our diagnostic confidence by revealing fine vessels within and around the FNH lesion.
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http://dx.doi.org/10.1007/s10396-017-0775-8DOI Listing
October 2017

Focal nodular hyperplasia: our experience of 53 Japanese cases.

J Med Ultrason (2001) 2017 Jan 22;44(1):79-88. Epub 2016 Aug 22.

Center of Diagnostic Ultrasound, Akita Red Cross Hospital, Akita, Japan.

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. The majority of the previous reports come from European countries, and a very few studies of large series designed to describe the clinical features in Japanese patients have been reported. The aim of this study was to (a) describe the clinical features in 53 patients (59 lesions) diagnosed with CEUS and (b) compare the data with those from the previous reports.

Methods: The medical data from 53 patients diagnosed on the basis of typical CEUS findings at our institution and affiliated hospitals were reviewed, and their clinical data were analyzed.

Results: (1) The medical data from 53 cases showed a slight male predilection, with 30 male cases (57 %) and 23 female cases (43 %), although the occurrence in both sexes was equal. FNH cases were distributed throughout all generations in both sexes, mostly concentrated in the age of 30-60 years old, and metabolic cases were more common in men than in women (4 vs 0). (2) The lesions were small (mean: 23 mm) and distributed throughout the whole liver. (3) Lesion size was not influenced by age in either sex. (4) A rapid draining to the hepatic vein was recognized in five out of 59 lesions (8 %).

Conclusions: Our data indicate that FNH occurs slightly more frequently in men than in women in Japan. It occurs also at any age in both sexes, but the mean lesion size was smaller in our series than in the previous reports. Metabolic disease was seen only in male FNH patients. A direct communication between the FNH lesion and the hepatic vein is diagnostically worth noting.
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http://dx.doi.org/10.1007/s10396-016-0734-9DOI Listing
January 2017

Searchlight phenomenon: a novel artifact of the gallbladder.

J Med Ultrason (2001) 2016 Apr 9;43(2):219-25. Epub 2016 Jan 9.

Center of Diagnostic Ultrasound, Akita Red Cross Hospital, 222-1 Kamikitate, Akita, Akita, 010-1495, Japan.

Background: "Searchlight phenomenon" is an ultrasound artifact that appears as thin, bright, and posteriorly extending lines in the gallbladder lumen. It mimicks the comet-tail artifact, but it does not decrease in intensity in the depth of the view field, unlike the comet-tail artifact.

Purpose: To determine the mechanism of this unpublished ultrasound artifact on the basis of clinical ultrasound images as well as using an in vitro system.

Materials And Methods: (1) CLINICAL STUDY: to determine the detection rate of the searchlight phenomenon in 453 subjects with a normal abdominal US examination result according to the medical chart. We also analyzed the appearance of the searchlight phenomenon in which US showed the searchlight phenomenon in the gallbladder. (2) Basic study: we placed a thin (thickness: 12 μm) polyethylene membrane at the depth of 2.5 cm from the transducer inside a water bath. Then, we inserted air bubbles (50-400 μm) below the membrane and observed when the ring-down artifact and searchlight phenomenon appeared.

Results: (1) CLINICAL STUDY: the searchlight phenomenon was observed in 30 out of 453 (6.6 %) subjects. When the searchlight phenomenon was seen, duodenal gas was present dorsally in the same line of sight, and the searchlight phenomenon appeared only when duodenal gas was accompanied by the ring-down artifact on US. (2) Basic study: a stepwise increase in the number of air bubbles gave rise to (a) multiple echo spots (single layer of air bubbles), (b) ring-down artifact (two layers), and (c) ring-down artifact below the membrane and searchlight phenomenon in front of the membrane simultaneously. The ring-down artifact and searchlight phenomenon always appeared in the same line of sight.

Conclusion: The searchlight phenomenon is thought to be a range-ambiguity artifact of the ring-down artifact. Duodenal gas is thought to give rise to this artifact. When examining the gallbladder with ultrasound, knowledge of many artifacts including the searchlight phenomenon can prevent us from making a hazardous misdiagnosis.
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http://dx.doi.org/10.1007/s10396-015-0697-2DOI Listing
April 2016

A case of gallbladder perforation detected by sonography after a blunt abdominal trauma.

J Clin Ultrasound 2014 Jun 22;42(5):301-4. Epub 2013 Oct 22.

Department of Surgery, Yokote Municipal Hospital, 5-31 Negishi-cho, Yokote-shi, Akita, 013-8602, Japan.

Gallbladder (GB) perforation is a very rare posttraumatic abdominal injury. It is potentially life-threatening, and good outcome requires early diagnosis. We present a case of isolated posttraumatic GB perforation in which the precise sonographic (US) diagnosis led us to apply proper management. Color Doppler US showed a clear to-and-fro flow signal passing through the perforation site, and contrast-enhanced US confirmed the presence of a small defect in the GB wall. When examining posttraumatic patients, the possibility of GB perforation must be kept in mind. Color Doppler US and contrast-enhanced US are the examinations of choice to detect the perforation site and show bile movement through the perforation.
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http://dx.doi.org/10.1002/jcu.22111DOI Listing
June 2014

Mobile echoes in liver cysts: a form of range-ambiguity artifact.

J Clin Ultrasound 2010 Nov-Dec;38(9):475-9

Internal Medicine, Yokote Municipal Hospital, Yokote-shi, Akita, Japan.

Purpose: Faint moving echoes are occasionally encountered in large hepatic cysts, as an example of range-ambiguity artifacts. The aim of this article is to describe the pattern of these intracystic mobile echoes, to analyze the mechanism of their formation, and to discuss options to clear them.

Methods: We analyzed the size and location of the hepatic cysts, the movement of the artifactual echoes, and the relationship between pulse repetition frequency (PRF) and the depth of these intracystic mobile echoes in 10 cases. In three cases examination at a lower PRF was made to ascertain whether the artifactual echoes would disappear.

Results: Intracystic range-ambiguity echoes appeared when the heart was located distal to the hepatic cyst and these echoes moved according to cardiac motion. The depth of the intracystic artifacts changed according to the PRF and they disappeared at a low PRF.

Conclusion: Intracystic range-ambiguity artifacts are caused by an erroneous display of the returning echoes from the heart. Knowledge of the mechanism and appearance of this artifact helps prevent misdiagnosis of internal echoes in large hepatic cysts. Observation at different PRFs is key to recognizing this artifact, and examination at lower PRFs should be done to confirm the artifactual nature of the echoes.
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http://dx.doi.org/10.1002/jcu.20746DOI Listing
February 2011

Rupture of liver metastasis: report of a case with an emphasis on contrast-enhanced US.

J Med Ultrason (2001) 2007 Jun 21;34(2):113-6. Epub 2007 Jun 21.

Center of Diagnostic Ultrasound, Akita Red Cross Hospital, Akita, Japan.

We present a case of liver metastasis from an uterine leiomyosarcoma in which contrast-enhanced ultrasonography (CEUS) helped determine the bleeding point and prevented a delay in devising diagnostic and therapeutic strategies. CEUS allowed us to differentiate active from nonactive bleeding on the basis of presence or absence of contrast extravasation in the ascites. CEUS is the first examination performed when liver tumor rupture is suspected. Reference to the preangiographic CEUS results is expected to provide a road map for angiography.
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http://dx.doi.org/10.1007/s10396-007-0140-4DOI Listing
June 2007

Malignant triton tumor in a patient with neurofibromatosis type 1.

J Med Ultrason (2001) 2007 Jun 21;34(2):107-11. Epub 2007 Jun 21.

Department of Pathology, Akita University School of Medicine, Akita, Japan.

We report a case of neurofibromatosis type 1 (NF1) complicated by a malignant triton tumor (MTT), with an emphasis on B-mode sonographic (US) and contrast-enhanced US (CEUS) findings. To the best of our knowledge, this is the first report describing CEUS findings of MTT. The mass was poorly demarcated and composed of an internal echogenic area and an outer hypoechoic zone. CEUS findings showed the outer zone to be strongly enhanced, and the internal area was very poor in blood flow because of necrotic tissues.
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http://dx.doi.org/10.1007/s10396-007-0138-yDOI Listing
June 2007

Contrast-enhanced sonographic findings in a case of hepatobiliary cystadenoma with intracystic bleeding.

J Clin Ultrasound 2006 Oct;34(8):412-5

Department of Internal Medicine, Yokote Municipal Hospital, 5-31 Negishi-cho, Yokote, Akita, Japan.

Intracystic slow bleeding is very difficult to diagnose using conventional sonography; consequently, a new sonographic technique has been sought. We present a histologically proven hepatobiliary cystadenoma with intracystic bleeding in which contrast-enhanced sonography (CEUS) showed microbubbles oozing from the cyst wall into the cystic cavity 10 minutes after intravenous injection of contrast medium. CEUS is an important diagnostic tool for diagnosing liver tumors, but the CEUS finding of slow intracystic bleeding has not been reported. Our observation suggests that this technique may be a new diagnostic tool for this purpose.
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http://dx.doi.org/10.1002/jcu.20262DOI Listing
October 2006

Hepatic cyst with intracystic bleeding: contrast-enhanced sonographic findings.

J Med Ultrason (2001) 2006 Jun;33(2):105-7

Center of Diagnostic Ultrasound, Red Cross Hospital, 222-1, Saruta, Kamikitade, Akita, 010-1495, Japan.

Intracystic bleeding is a relatively rare complication of hepatic cysts, which is very difficult to diagnose by conventional sonography (US). Hence, a new US technique has been sought for this purpose. We present the case of a hepatic cyst with intracystic bleeding in which contrast-enhanced US showed microbubbles oozing from the cyst wall into the cystic cavity. Contrast-enhanced US is now an important diagnostic tool for diagnosing liver tumors, but contrast-enhanced US findings relating to intracystic bleeding have not been reported. Our observations suggest that this technique may be a useful new diagnostic tool for this purpose.
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http://dx.doi.org/10.1007/s10396-005-0084-5DOI Listing
June 2006

Errors in measuring blood flow velocity behind hepatic mass lesions using color doppler sonography.

J Med Ultrason (2001) 2003 Sep;30(3):133-40

First Department of Internal Medicine, Akita University School of Medicine, 1-1-1 Hondo, Akita, Japan.

The authors designed microcomputer simulation models to investigate the combined effect of a distorted grayscale ultrasound image and an inaccurately measured Doppler angle on the accuracy of measurement of blood-flow velocity in vessels located behind mass lesions in the liver. Error decreased when flow was measured at the midpoint of the posttumoral segment of the vessel and increased with distance between the mass and the vessel, with inclination of the vessel, and with decrease in the diameter of the mass. Error was least with the sector probe, intermediate with the convex probe, and greatest with the linear probe. These findings suggest that the error can be minimized when measuring blood flow velocity in a vessel located behind a mass, if the Doppler images are acquired using a sector probe from the midpoint of the posttumoral segment of the vessel.
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http://dx.doi.org/10.1007/BF02481218DOI Listing
September 2003

Image distortion in US-guided liver tumor puncture with curved linear array.

Eur Radiol 2003 Jun 6;13(6):1291-6. Epub 2002 Dec 6.

First Department of Internal Medicine, Akita University School of Medicine, 1-1-1 Hondo, Akita City, Akita 010-8543, Japan.

Our objective was to systematically examine the influence of probe geometry, puncture route, and composition of the abdominal wall on the deviation error with needle display. We made a simplified simulation model of the puncture needle passing to the liver tumor, using a microcomputer system, and visualized the degree of distortion of the puncture needle, changing the thickness and component of the abdominal wall as well as the radius of the probe, site, and angle of puncture. The puncture needle exhibited a displacement error of -10.9 to 3.8 mm (center hole) and -11.3 to 3.8 mm (side attachment). The shift was less accentuated when the radius of the probe was large. The displacement error was less accentuated in the center and accentuated in the left side of the field of view. It is recommended that liver puncture under US guidance be generally performed using a probe with a larger radius through the center hole with the most obtuse puncture angle possible, but when the tumor is localized in the hepatic dome, a more tightly curved probe should be used with an acute angle. We must consider a possible large error in display of the puncture needle during liver puncture and try to prevent hazardous complications.
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http://dx.doi.org/10.1007/s00330-002-1711-9DOI Listing
June 2003
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