Biomedical subjects

H Naganuma

Publications and source records attributed to H Naganuma.

At least 163 records · Page 9Linked to original sources

PubMedDate not supplied

Renal arteriovenous malformation: sonographic findings.

BACKGROUND AND METHODS: Renal arteriovenous malformation (RAVM) is a relatively rare congenital disease. Although sonography (US) currently is the first diagnostic tool for examining the kidney, its US and color Doppler findings have seldom been reported. We reviewed the clinical manifestations and US results of five cases of RAVM to clarify the role and limitations of US in the diagnosis. RESULTS: The lesions were solitary in all cases, and the affected side was the right in four cases and the left in one case. In four cases, the patients complained of hematuria, but the remaining case had no symptoms. US did not detect the lesion, but in all cases color Doppler US showed a focal vascular lesion with posterior color spots. US reexamination with knowledge of the Doppler results did not show any focal lesion. CONCLUSION: US was not diagnostic for RAVM, and color Doppler US should be performed immediately in patients with hematuria.

Arteriovenous Malformations↗

PubMedDate not supplied

Segmental chronic cholecystitis: sonographic findings and clinical manifestations.

BACKGROUND: In chronic cholecystitis, the gallbladder (GB) wall is usually evenly involved, whereas marked segmental thickening of the GB wall (segmental cholecystitis) seldom is reported. We wanted to define its clinical manifestations and sonographic (US) findings. METHODS: We reviewed the clinical and US data of 13 cases and compared these results with those of 30 patients with chronic cholecystitis with evenly thickened GB walls (usual-cholecystitis group). RESULTS: (a) All cases of segmental cholecystitis showed the portion distal to the kinking to be markedly thickened. (b) The thickened portion corresponded to the fundus in three cases, the body and fundus in seven cases, and the fundus, body, and infundibulum in three cases; and the thickened distal portion contained many stones in 11 cases. (c) There was no difference in the maximal diameters of the GB walls between the segmental-cholecystitis group and the usual-cholecystitis group. However, there was a significant difference in the minimal diameters of the GB walls between groups. CONCLUSION: Knowledge of the US findings and clinical presentations of segmental cholecystitis can help in the development of appropriate diagnostic and therapeutic strategies.

Adult↗

PubMedDate not supplied

Gallbladder perforation: color Doppler findings.

Gallbladder (GB) perforation is a life-threatening complication of acute cholecystitis, and early diagnosis prevents delay in patient management. We present two cases of GB perforation diagnosed by color Doppler ultrasonography. Each clearly showed a flow signal passing through the perforated site, leading to prompt and successful surgical treatment. This interesting observation suggests that color Doppler ultrasonography is useful in the diagnosis of GB perforation.

Acute Disease↗

PubMedDate not supplied

Emphysematous cholecystitis: sonographic findings.

BACKGROUND: Emphysematous cholecystitis (EC) is a rare but life-threatening complication of acute cholecystitis, and an early diagnosis is required to prevent delay in patient management. Because sonography (US) is the first choice for diagnosing gallbladder diseases, US findings of EC should be understood more precisely. METHODS: We reviewed US findings of 11 surgically proven cases of EC (with small amounts of gas in three cases and large amounts in eight cases) and compared those with patients' clinical data. RESULTS: (1) In cases with small amounts of gas, US showed an echogenic line with a distinct ring-down artifact or a "powder snow-like" speckled posterior echo. (2) In cases with large amounts of gas, US showed a wide spiculated echogenic band with a powder snow-like speckled posterior echo or a speckled acoustic shadowing. In all cases, the presence of gas prevented visualization of the gallbladder wall. (3) US did not differentiate gas localized to the gallbladder wall and gas extending to the surrounding hepatic tissue. (4) Two diabetic cases showed gas throughout the intrahepatic bile ducts. In those cases, the time from diagnosis to recovery was relatively long. CONCLUSION: Our series showed some characteristic US patterns of EC. A good understanding of its US findings and appropriate emergent management will reduce the serious morbidity and mortality rates caused by EC.

Aged↗

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↗

PubMedDate not supplied

Primary carcinoid tumor of the liver: report of two cases with an emphasis on US findings.

Primary carcinoid tumor of the liver is rare, and its sonographic (US) findings have rarely been reported. We present two histologically proven cases. Both patients were asymptomatic and huge masses, found incidentally by US, were echogenic with many cystic areas. Lesions were markedly hypervascular on color Doppler US and angiography. Thus, primary carcinoid tumor of the liver should be considered when US detects this type of mass in asymptomatic patients.

Adult↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗

PubMedDate not supplied

Differentiation of exudate from transudate ascites by Doppler sonography.

BACKGROUND: We investigated whether the addition of Doppler sonography (US) increases the diagnostic confidence of US for estimating the nature of ascites. METHODS: Of the 127 cases reviewed in this study, there were 42 cases of transudate and 85 of exudate ascites. We reviewed the US, power Doppler, and pulsed Doppler images of these cases. RESULTS: With US, the transudate ascites was imaged as free of echo in 38 of 42 cases (90.5%). The exudate ascites was imaged as free of echo in 22 of 85 cases (25.9%) and with internal echo spots in 63 of 85 cases (74.1%). With Doppler US, we obtained distinct pulsed signals from the transudate ascites in only two of 36 cases (5.6%). In contrast, we obtained distinct Doppler signals from the exudate ascites in 66 of 79 cases (83.5%). Those 66 cases included 16 of the 22 cases with echo-free ascites. CONCLUSION: The presence or absence of echo spots within the ascites helped differentiate transudate from exudate ascites, as reported in the literature. However, the addition of Doppler US contributed to the differentiation of echo-free exudate (Doppler signals present) from echo-free transudate (Doppler signals absent) ascites.

Abdomen↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗