Biomedical subjects

J Ishida

Publications and source records attributed to J Ishida.

At least 109 records · Page 6Linked to original sources

PubMedDate not supplied

Accessory hepatic duct: sonographic findings.

Accessory hepatic ducts are relatively rare biliary anomalies. They have been reported only sporadically, and very few reports have described their sonographic (US) findings. Our experience with two such cases suggested that a diagnosis of an accessory hepatic duct should be considered when US shows a fine tubular structure or an anechoic or hypoechoic oval mass with acoustic shadowing at the level between the hepatic hilus and the common bile duct. A good knowledge of the US findings will determine the diagnostic and therapeutic strategies.

Aged↗

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Abdominal lymphoma: differentiation from pancreatic carcinoma with Doppler US.

BACKGROUND: Marked lymphadenopathy around the pancreas due to lymphoma (abdominal lymphoma) occasionally can mimic a total pancreatic carcinoma on ultrasonography (US). We investigated whether US and color Doppler US allowed differentiation between those pathologies. METHODS: We analyzed the US and color Doppler results of 12 cases of abdominal peripancreatic lymphoma and 21 cases of total pancreatic carcinoma. RESULTS: With regard to shape, echogenicity of the lesion, and mode of vascular involvement, there was no difference between groups. With regard to maximal velocities and resistive indices of the involved vessels, there was no difference between groups. However, the presence of turbulent flows in the involved vessels was seen exclusively in the pancreatic carcinoma group. CONCLUSION: The presence or absence of turbulent flow in the involved vessels is a very important finding for differentiating abdominal lymphomas from total pancreatic carcinomas.

Abdominal Neoplasms↗

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Retroperitoneal cyst: sonographic findings.

BACKGROUND: Retroperitoneal cyst (RC) is a relatively rare disease, and its sonographic (US) findings have not been analyzed sufficiently. METHODS: We studied US findings of five patients with RC, with special attention to location, size, shape, internal echoes, the presence or absence of lateral shadowing, and the mode of back echoes. RESULTS: In all cases, the cyst was situated behind (four cases) or lateral to (one case) the pancreas: behind or lateral to the pancreatic head in two cases, behind the pancreatic body in one case, and behind the pancreatic tail in two cases. Four cases showed a round mass (three cases) or multiple round mass (one case). Internal echoes were present in those cases and showed a "pseudo-solid" pattern. In those cases, M-mode US confirmed the movement of those internal echoes. In the remaining case, the lesion was imaged as an irregularly shaped multilocular mass. No case showed posterior echo enhancement, and no case showed lateral shadowing. No blood flow signals from the lesion were seen. CONCLUSION: Unlike ordinary cysts, RC usually is imaged as a round mass behind the pancreas, with dense internal echoes without lateral shadowing or posterior echo enhancement, which presents a "pseudo-solid" pattern. A diagnosis of RC should be considered when encountering a mass with such US findings.

Child, Preschool↗

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Dilatation of the cystic duct in patients with obstructive jaundice.

BACKGROUND: It is well known that obstructive jaundice causes biliary dilatation, but sonographic (US) findings of the cystic duct in patients with obstructive jaundice are rarely reported. METHODS: We reviewed US findings in 25 such patients. RESULTS: US findings of dilated cystic duct could be divided roughly into two patterns: tortuous and tubular. The former pattern was a tortuously dilated cystic duct arising from the gallbladder neck, running predominantly deeply, turning anteromedially, and then joining the posterior face of the common hepatic duct. The latter pattern was a straight dilated cystic duct running parallel with the common hepatic duct, giving the appearance of a septated bile duct. CONCLUSION: A better understanding of the US findings of dilated cystic duct translates into improved biliary US diagnosis.

Adult↗

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Appendiceal mucocele: sonographic findings.

BACKGROUND: Appendiceal mucocele (AM) is a relatively rare disease, and its sonograms (US) have not been sufficiently analyzed. METHODS: We studied the US findings of five patients with AM, with special attention to AM size, shape, internal echoes, and the mode of back echoes. RESULTS: All five cases showed an elongated mass in the lower right abdomen. Internal echoes were present in all cases and M-mode US confirmed the movement of those echoes. The echogenecity of the lesion changed according to the frequency of the transducer used. Only one case showed posterior echo enhancement, and no case showed lateral shadowing. CONCLUSION: AM appears as an elongated echo-poor mass without posterior echo enhancement. The cyst wall is less distinct than what one would expect for a cyst. When encountering such a mass in the lower right abdomen, one should strongly suspect an AM. In such cases, appropriate diagnostic and therapeutic strategies are especially necessary to prevent rupture that results in development of pseudomyxoma peritonei.

Aged↗

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Chilaiditi syndrome: sonographic findings.

BACKGROUND AND METHODS: Sonographic (US) findings of Chilaiditi syndrome have been rarely reported in the literature. We reviewed 18 cases of Chilaiditi syndrome to pinpoint its US pattern. RESULTS: (1) US showed gas echoes of different sizes superimposed over the entire liver in two cases and over the right hepatic lobe in six cases, leading to a high suspicion of Chilaiditi syndrome. (2) US showed a small gas echo in the hepatodiaphragmatic space, mimicking pneumoperitoneum in eight cases. In this instance, altering the patient's position allowed for confirmation of the lack of a change in the location of the gas echo, unlike cases of pneumoperitoneum. (3) The hepatic surface appeared as a hyperechoic mass in two cases. CONCLUSION: Knowledge of US patterns of Chilaiditi syndrome helps avoid confusion with pneumoperitoneum or hepatic masses.

Aged↗

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Mesenteric cyst: sonographic findings.

BACKGROUND: Mesenteric cyst (MC) is a relatively rare disease, and its sonographic characteristics have not been sufficiently analyzed. METHODS: We studied the sonographic findings of eight patients with MC, with attention paid to its size, shape, internal echoes, and especially the presence or absence of lateral shadowing and the mode of back echoes. In four cases, the sound velocity and acoustic impedance of cystic fluid were also measured. The mode of blood flow was evaluated by color Doppler sonography. RESULTS: Six cases showed an oval or comma-shaped mass. Internal echoes were present in six cases, and two of them showed a pseudosolid pattern. In these cases, M-mode sonography confirmed the movement of these internal echoes. Only one case showed a posterior echo enhancement, and no case showed lateral shadowing. Sound velocity measured in four cases was 1,515-1,537 m/s, with an acoustic impedance of 1.550-1.576 kg/m2/s. No blood flow signals were obtained from the lesion. CONCLUSION: MC exhibits so many patterns on ultrasound that we should consider the possibility of MC when encountering an avascular oval mesenteric mass.

Adolescent↗

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Adenosquamous carcinoma of the pancreas: report of two cases.

Adenosquamous carcinoma (ASqC) of the pancreas is a rare tumor. We analyzed the radiologic findings and clinical manifestations in two such cases. In both cases (a 51-year-old woman and a 67-year-old man), the portal system was selectively and largely invaded, the superior mesenteric vein in one and the splenic vein in the other, without arterial invasion. Thus, peripancreatic vessels should be carefully observed in patients with ASqC of the pancreas. One case showed an unusual mode of spread. Only a huge metastatic lesion was initially detected, leading to the misdiagnosis of primary malignant mesenteric tumor. Such an unusual growth pattern is also worth noting.

Aged↗

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Liver tumors in children and young patients: sonographic and color Doppler findings.

BACKGROUND: Liver tumors are a relatively rare pathologic condition in children and young patients. The aim of the present study was to categorize the sonographic (US) and color Doppler results of liver tumors in these patients. METHODS: We retrospectively reviewed the US findings of 23 such cases: malignant tumor (13 cases)-hepatoblastoma (four cases), hepatocellular carcinoma (HCC; four cases), and hepatic metastasis (five cases); benign tumor (10 cases)-hepatocellular adenoma (four cases), focal nodular hyperplasia (two cases), mesenchymal hamartoma (two cases), cystadenoma (one case), and hemangioendothelioma (one case). RESULTS: There was no specific US findings for each tumor type. HCC usually developed on a normal liver and was imaged as multiple nodules. Color Doppler US helped in differentiating multiple metastatic nodules (hypovascular) from multiple HCC nodules (hypervascular). Presence of intratumoral cystic areas was usually suggestive of benign tumors. Follow-up US was useful for detecting small nodules in high-risk groups (congenital biliary atresia, glycogen storage disease). Color Doppler US helped in diagnosing portal thrombus or intratumoral shunt. CONCLUSION: Although there were no highly specific findings, US and color Doppler results contributed, to a certain degree, to the diagnosis of liver tumors in children and young adults by showing intratumoral cystic areas or vascularity.

Adolescent↗

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Abdominal involvement in neurofibromatosis 1: sonographic findings.

BACKGROUND: Neurofibromatosis 1 (NF1) has been studied from many viewpoints, but its abdominal involvement has rarely been reported. Sonography (US) is now the initial diagnostic tool for abdominal exploration, which prompted us to determine the clinical manifestations and US findings of abdominal involvement in NF1. METHODS: We analyzed the US findings and clinical data of eight NF1 cases with abdominal involvement. RESULTS: Abdominal involvement included neurofibromatous tumor growth in the liver, mesentery, and retroperitoneum, in addition to mesenteric leiomyomatosis and gastric carcinoma. Color Doppler US was useful not only in detecting blood flows in the lesions but also in preventing hazardous vascular injury during tumor biopsy. CONCLUSION: A better understanding of the clinical manifestations and US findings of abdominal involvement in NF1 translates into improved NF1 patient care.

Abdominal Neoplasms↗

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Retroperitoneal liposarcoma: sonographic findings.

This study, based on sonographic (US) results of 10 cases with histologically proven retroperitoneal liposarcoma (eight well-differentiated and two pleomorphic types), shows that the presence of fine echogenic lines within the tumor is a useful sign for diagnosing a well-differentiated liposarcoma. Presence of numerous fine fibrous septa in the lipomatous tumor tissue is thought to be responsible for this interesting phenomenon. Of interest is the fact that the direction of these lines changed according to the probe format used: parallel horizontal lines when using a linear probe and concentric lines converging toward the probe when using a sector or curved linear probe. In contrast, pleomorphic liposarcoma does not show this US sign. Knowledge of these US findings is useful for the diagnosis of retroperitoneal liposarcoma.

Adult↗

PubMedDate not supplied

Macronodular hepatic deformity on normal liver.

BACKGROUND AND METHODS: Macronodular hepatic deformity on normal liver is very rare. We present nine such cases and try to define the characteristic clinical and ultrasound (US) findings. RESULTS: In the left lobe, the lateral segment was replaced by multiple nodules and the medial segment was very atrophied and irregularly shaped. Compared with the left lobe, the right lobe showed very few abnormalities except for segment 6, which showed a macronodular deformity. These nodules, regardless of diameter or lobe, showed a relatively homogeneous internal structure and were isoechoic relative to the surrounding hepatic parenchyma. These multinodular changes on US corresponded to multiple regenerative nodules identified at laparoscopic evaluation. On color Doppler US and angiography, the major intrahepatic vessels were patent in all cases. CONCLUSION: Although relatively rare, the macronodular hepatic deformity on normal liver collected in our series showed a characteristic appearance by US. A good understanding of its characteristics may help sonographers in differentiating it from other, more common hepatic deformities.

Adult↗

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Pancreatic metastasis: sonographic findings.

BACKGROUND: Pancreatic metastasis is a relatively rare pathologic condition. Its ultrasound (US) findings have been infrequently reported, and there has been no previous report describing its color Doppler findings. METHODS: We reviewed the US findings of 13 such cases. RESULTS: The pancreatic metastasis consisted of a single hypoechoic nodule in four cases and multiple hypoechoic nodules in nine cases. US showed a slight dilatation of the main pancreatic duct in two cases of pancreatitis, and a marked biliary dilatation in one case of jaundice. The US results prompted introduction of appropriate treatment in these cases. Color Doppler US was useful for confirming the absence of flow abnormalities in the arterial and portal systems around the pancreas. In a patients with renal carcinoma metastasis, it showed many fine blood flow signals in the metastatic lesions. CONCLUSION: The role of US in the diagnosis of pancreatic metastasis consists of associated complications such as biliary dilatation or pancreatitis and detection of isolated lesions. Additional information provided by color Doppler US may increase diagnostic confidence.

Adult↗

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Pancreatic uncinate carcinoma: sonographic findings.

BACKGROUND: Pancreatic carcinoma arising from the uncinate process (pancreatic uncinate carcinoma) is relatively rare. We wished to define its clinical manifestations and sonographic findings. METHODS: Clinical and sonographic data of eight cases were reviewed. RESULTS: The common bile duct and the pancreatic duct were not dilated until a very late stage. The lesion mimicked a mesenteric tumor in two cases. The superior mesenteric vessels were compressed anteriorly. Computed tomography was useful, not only for confirming the pancreatic uncinate origin of the lesion but also for determining precisely the mode of mesenteric vascular involvement. CONCLUSION: Knowledge of these unusual sonographic findings can determine the diagnostic strategy in pancreatic uncinate carcinoma.

Aged↗

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Macronodular deformity of the spleen.

BACKGROUND AND METHODS: Macronodular splenic deformity without a focal lesion has rarely been reported. We present three such cases and discuss the possible pathomechanism. RESULTS: There was one case of macronodular deformity of unknown cause. In this case, the liver was elongated anteriorly over the dome of the spleen, and the markedly deformed spleen mimicked a round lesion in the left lobe of the liver. Color Doppler ultrasonography showed the major intra- and perisplenic vessels to be patent. There were two cases of macronodular deformity associated with extended portal thrombosis. In both cases, portal thrombosis extended throughout the intrahepatic and extrahepatic portal systems, and this portal flow disturbance was presumed to be the cause of the splenic deformity. CONCLUSION: Although very rare, thrombosis should be sought throughout the portal system when ultrasonography shows a markedly deformed spleen. Marked splenic deformity, especially in cases with an elongated liver, may mimic a liver tumor. A good understanding of its sonographic appearance may help sonographers prevent a hazardous misdiagnosis.

Adult↗

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Choledochal cyst due to anomalous pancreatobiliary junction in the adult: sonographic findings.

BACKGROUND: Adult cases of choledochal cyst due to anomalous pancreaticobiliary duct junction have been rarely reported. At present, sonography (US) is the first tool for diagnosing biliary disorders. The aim of this study was to reevaluate the US findings of choledochal cysts due to anomalous pancreaticobiliary duct junction in adults. METHODS: We reviewed the clinical manifestations and US findings of 12 such adult cases confirmed by endoscopic retrograde cholangiopancreatic ductography (ERCP). Patients were assigned to three groups: (a) associated with biliary carcinoma (two cases), (b) associated with choledocholithiasis (one case), and (c) not associated with other abdominal diseases (nine cases). RESULTS: Patients in group c were asymptomatic, and the lesions were detected incidentally detected by US. In contrast, patients in group a sought medical care because of symptoms such as jaundice and those in group b sought medical attention because of abdominal pain. The diameter of a dilated bile duct on US was considerably less than that of ERCP (ERCP: 26-58 mm, mean = 37.6 mm; US: 13-32 mm, mean = 21.8 mm). Its diameter changed significantly under probe compression when the dilated bile duct took a purely cystic form but changed very little when it took a tubular form. CONCLUSION: Unlike cases in children, adult cases of choledochal cyst are generally asymptomatic. Careful US observation of the bile duct is thus expected to detect asymptomatic adult choledochal cysts cases. Cyst diameter can change significantly under probe compression, so it is important not to compress the bile duct during routine US examination.

Adult↗

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Duodenal carcinoma: sonographic findings.

BACKGROUND: Duodenal carcinoma is a relatively rare tumor and its sonographic (US) findings have rarely been reported. METHODS: We reviewed the clinical data and US results of 15 patients with histologically proven duodenal carcinoma to pinpoint the contribution of US to the diagnosis. RESULTS: US was useful for not only detecting the duodenal carcinoma (13 of 15, 86.7%), which altered the endoscopic procedure in nine patients, but also for evaluating vascular involvement (marked portal invasion in four cases and inferior vena cava invasion in two cases). Four of the eight carcinomas arising from the second or third portion showed this vascular invasion. CONCLUSION: After reviewing the clinical data and US results of 15 cases of duodenal carcinoma, we found that US was useful for detecting duodenal carcinoma and determining vascular invasion. Thus, US contributed significantly to alter the endoscopic procedure and patient management.

Carcinoma↗

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Mycotic abdominal aneurysm: report of a case with emphasis on the presence of gas echoes.

Mycotic abdominal aneurysm is a relatively rare disease and its sonographic (US) findings have rarely been reported. We present a case of mycotic aneurysm of the common iliac artery in which the initial US showed a slightly wall-thickened abdominal aorta with gas echoes in the wall, a second US 6 days later showed a rapid increase in aortic size, and an emergent surgical intervention showed a mycotic aneurysm. This interesting observation suggested that the presence of gas echoes is a useful US finding indicating the beginning of a mycotic aneurysm and, when encountering this US finding, that emergent treatment should be considered to prevent delay in patient management.

Aged↗