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Biomedical subjects

A Scherrer

Publications and source records attributed to A Scherrer.

At least 19 recordsLinked to original sources
PubMed1995

MR diagnosis of hepatic metastases from neuroendocrine tumors versus hemangiomas: relative merits of dynamic gadolinium chelate-enhanced gradient-recalled echo and unenhanced spin-echo images.

OBJECTIVE: Hepatic metastases from neuroendocrine tumors are often markedly hyperintense on unenhanced T2-weighted MR images, making their appearance similar to that of cavernous hemangiomas. In contrast, cavernous hemangiomas show characteristic enhancement on dynamic gadolinium chelate-enhanced gradient-recalled echo MR images. The purpose of this study was to determine the relative merits of dynamic gadolinium chelate-enhanced gradient-recalled echo MR imaging versus MR imaging with unenhanced spin-echo pulse sequences for distinguishing between hepatic metastases from neuroendocrine tumors and cavernous hemangiomas. MATERIALS AND METHODS: The unenhanced spin-echo and dynamic gradient-recalled echo MR images obtained after IV administration of a gadolinium chelate in 28 patients (14 patients with pathologically proven hepatic metastases from neuroendocrine tumors and 14 patients with hepatic cavernous hemangiomas) were reviewed blindly and independently by three interpreters. Unenhanced spin-echo and dynamic gadolinium chelate-enhanced gradient-recalled echo MR images were compared for accuracy in characterizing liver lesions. RESULTS: The most intense enhancement of hepatic metastases from neuroendocrine tumors was observed on early dynamic gadolinium chelate-enhanced gradient-recalled echo MR images; enhancement was peripheral in four patients, global and heterogeneous in seven patients, and global and homogeneous in three patients. On late dynamic gadolinium chelate-enhanced gradient-recalled echo MR images, enhancement of hepatic metastases from neuroendocrine tumors was predominantly peripheral in five patients, global and heterogeneous in five patients, and global and homogeneous in four patients. Differentiation between cavernous hemangiomas and hepatic metastases from neuroendocrine tumors was impossible in five cases with unenhanced spin-echo MR imaging alone, in five cases with dynamic gadolinium chelate-enhanced gradient-recalled echo MR imaging alone, and in no case with the combination of unenhanced spin-echo MR imaging and dynamic gadolinium chelate-enhanced gradient-recalled echo MR imaging. In comparison with unenhanced spin-echo MR imaging alone or dynamic gadolinium chelate-enhanced gradient-recalled echo MR imaging alone, the combination of unenhanced spin-echo MR imaging and dynamic gadolinium chelate-enhanced gradient-recalled echo MR imaging allowed significantly (p < .001) clearer differentiation between hepatic metastases from neuroendocrine tumors and cavernous hemangiomas. CONCLUSIONS: Early enhancement and heterogeneity on dynamic gadolinium chelate-enhanced gradient-recalled echo MR images are the most common features of hepatic metastases from neuroendocrine tumors. The combination of unenhanced spin-echo and dynamic gadolinium chelate-enhanced gradient-recalled echo MR images allows more accurate characterization of hepatic metastases from neuroendocrine tumors and clearer differentiation from cavernous hemangiomas.

Abdominal Neoplasms↗
PubMed1995

Imaging of intrahepatic cholangiocarcinoma: 1. Peripheral cholangiocarcinoma.

Cholangiocarcinoma is the second most common primary hepatic malignant tumor after hepatocellular carcinoma, accounting for 5-30% of all primary hepatic malignant tumors [1]. Intrahepatic cholangiocarcinomas can be classified as peripheral cholangiocarcinoma, which originates from an interlobular biliary duct, or as hilar cholangiocarcinoma, which originates from a main hepatic duct or from the bifurcation of the common hepatic duct. Intrahepatic cholangiocarcinomas account for only about half of cholangiocarcinomas, and this pictorial essay focuses only on the peripheral form of the disease. Clinically, therapeutically, and radiologically, these two types of cholangiocarcinomas differ. Features suggestive of the diagnosis of peripheral cholangiocarcinoma can be shown by sonography, CT, and MR imaging. Cholangiography and angiography have a limited role in evaluating this neoplasm that manifests as a focal mass. This essay reviews the appearances of peripheral cholangiocarcinoma and discusses the various imaging techniques that can be used to evaluate this unusual tumor that is often resectable and potentially curable.

Adult↗
PubMed1995

Imaging of intrahepatic cholangiocarcinoma: 2. Hilar cholangiocarcinoma.

Hilar cholangiocarcinoma (also called Klatskin's tumor) is more common than peripheral cholangiocarcinoma. Sonography, CT, MR imaging, angiography, and cholangiography can suggest the diagnosis, but the major issue of imaging with this tumor is to determine whether the tumor is resectable. The anatomic location of hilar cholangiocarcinoma makes resection difficult, so that surgical exploration of patients with this condition should be undertaken only when preoperative evaluation has shown a potential for curative resection. Preoperative assessment of resectability of hilar cholangiocarcinoma is often extensive, requiring several types of imaging. This pictorial essay reviews the imaging features of hilar cholangiocarcinoma. The role of imaging in the preoperative planning, with specific emphasis on staging extent of disease, including hepatic and vascular involvement, is discussed and illustrated.

Adult↗
PubMed1991

Plasminogen activator inhibitor-2 in patients with monocytic leukemia.

Plasma and tumor cells from 103 patients with leukemia or lymphoma at initial presentation were investigated for the presence of plasminogen activator inhibitor-2 (PAI-2) antigen, a potent inhibitor of urokinase. PAI-2 was detected in plasma and leukemic cells of the 21 patients with leukemia having a monocytic component [acute myelomonocytic (M4), acute monoblastic (M5), and chronic myelomonocytic leukemias], and in the three patients with acute undifferentiated myeloblastic leukemia (M0). In contrast, this serine protease inhibitor was undetectable in 79 patients with other subtypes of acute myeloid leukemia or other hematological malignancies. Serial serum PAI-2 determinations in 16 patients with acute leukemia at presentation, during therapy, remission, and relapse revealed that in the five patients with M4-M5, elevated PAI-2 levels rapidly normalized under therapy and during remission, but increased again in the patients with a relapse associated with an M4-M5 phenotype. Thus, PAI-2 seems to be a marker highly specific for the active stages of monocytic leukemia, i.e. presentation and relapse. The presence of PAI-2 in the plasma and cells of patients with M0 may give a clue to a monocytic origin of these cells.

Antigens, Neoplasm↗
PubMed1990

Comparison between ultrasonographic signs and the degree of portal hypertension in patients with cirrhosis.

The sensitivity of ultrasonography (US) for the diagnosis of portal hypertension was assessed in 48 patients with known cirrhosis. These results were compared to the hemodynamic values obtained on the same day by hepatic vein catheterization. The sensitivity of US in detecting portal hypertension was about 40% considering either a greater than 13 mm diameter of the portal vein, or the lack of mild caliber variation of the superior mesenteric vein. The sensitivity was more than 80% considering the presence of portosystemic venous collaterals. Presence of numerous portosystemic shunts was significantly associated with high hepatic venous pressure gradients which reflected the severity of portal hypertension.

Female↗
PubMed1990

CT of malignant anal canal tumors.

Radiation therapy of malignant neoplasms of the anal canal has promising results in the majority of patients if the disease is limited at initial diagnosis. Computed tomography (CT), especially when performed with contrast material injected intravenously, is valuable in the pre- and posttreatment assessment of the anorectal musculature and perirectal nodes. The authors review the anatomy of the anorectal area and their experience with CT evaluation of anal canal cancer in a series of 26 patients. They also discuss their experience with treatment of this cancer in a series of 48 patients.

Anal Canal↗
PubMed1989

[Diagnosis of disorders affecting hollow intra-abdominal organs].

Modern imaging methods, including ultrasonography, computerized tomography and magnetic resonance imaging, add considerably to the information provided by the classical exploratory methods for hollow intra-abdominal viscera. They evaluate the size of these viscera and especially their wall and they are particularly useful when the lesion is transparietal, submucosal or even sub-adventitial. They also detect abscesses originating in the gastrointestinal tract, measure the extent of tumoral expansion beyond the mucosa and reveal intra-abdominal abnormalities associated with the lesions. The new methods, therefore, are very useful and often indispensable as a complement to other methods used to explore the digestive tract.

Gastrointestinal Diseases↗
PubMed1989

[Value of a score using clinical and biological variables for determining the benignity or malignancy of a hepatic mass].

The purpose of this study was to show that clinical and biological data can help in the diagnosis of benignity and malignancy in liver tumors seen on ultrasound. Three hundred and ninety-four patients with liver masses detected by ultrasound (270 malignant, 124 benign) were prospectively studied. Clinical and biological data were tested by univariate and multivariate analysis. The most important variables were gamma-glutamyl-transferase, sedimentation rate, known primary cancer, proven cirrhosis, abnormal abdominal palpation, ascites and weight loss. A regression model was used and a score was defined with these variables. Using this score, 94.8 p. 100 of the liver masses were accurately classified as benign and malignant tumors.

Diagnosis, Differential↗
PubMed1987

[Aid to the clinical and biological diagnosis of malignancy in a nodular hepatic image discovered by echography].

When ultrasound examination of the upper abdomen detects a liver nodule, the malignancy of this lesion must be discussed. If past history of cancer is known, a benign lesion cannot be excluded. Conversely, if the examination is performed without a history of cancer, we must raise the possibility of a malignant lesion. We attempted to demonstrate that the simple clinical and biological findings allow, if well used, a diagnosis of malignancy or benign nature, rather than performing further investigations, sometimes costly or invasive. We therefore compared three different methods: the well known bayesian diagnostic process; the multivariate analysis using logistic regression model; the Decision Theory, constructing a binary discrimination tree. The three methods lead to approximately the same rate of well classified patients (93 to 95%). Advantages and disadvantages are discussed.

Analysis of Variance↗
PubMed1986

[Radiologic surveillance of irradiated glomal tumors].

A favorable clinical result was obtained in 10 patients with jugular glomal tumors treated by external radiotherapy (approximately 50 Gy), alone or combined with surgical treatment, and preceded in some cases by embolization. Radiologic review examinations showed complete stability of lesions without bone reconstruction phenomena, in spite of a decrease in tympanic mass and regression of functional symptoms.

Adult↗
PubMed1985

Sonographic and computed tomographic evaluation of intrahepatic calculi.

Intrahepatic calculi in non-Asian patients were studied by sonography and computed tomography (CT). Three patients were studied by CT cholangiography also. In two cases, the calculi were consecutive to Caroli disease, and in two others, the biliary stones were formed proximal to a stenosis of a previous surgical anastomosis. Five patients spontaneously developed intrahepatic calculi. All sonograms were abnormal. Image specificity was good, even when bile ducts were not dilated, if appropriate technique allowed identification of a double-arc-shadow pattern. Sonography strongly suggested the diagnosis in eight patients and was nonspecific in only one. On CT, calculi had various densities, and they were not visible in two patients. CT cholangiography was not particularly helpful. Finally, CT added little more information when performed after sonography. Both examinations strongly underestimate the number of stones, and direct cholangiography remains indicated if surgery is planned.

Adult↗
PubMed1985

[Glomus jugulare tumors. Possibilities of radiotherapy].

From 1964 to 1981, twelve patients with glomus jugulare tumors involving bony lesions of base of skull were treated by high energy radiation. Ten patients presented cranial nerve pairs paralysis. Conventionally fractionated doses of 45 to 60 Gy were applied, and 11 of the 12 patients were alive and clinically stable after follow up for between 3 and 20 years. One patient died of an intercurrent infection after 16 years. Strict irradiation technique is essential to avoid principally neurologic complications. Favorable results after radiotherapy were obtained in extensive tympano-jugular forms.

Adult↗
PubMed1985

[Metastases of breast angiosarcoma. Apropos of 2 cases].

Two patients with breast angiosarcoma and hepatic and splenic metastases developed a hemoperitoneum confirmed by ultrasound and CT scan imaging. This complication has further adverse effects on the already extremely poor prognosis of this disease.

Adult↗
PubMed1985

[Value of the sitting position for studying suprahepatic veins by ultrasonography].

Ultrasound imaging of suprahepatic veins was conducted in 50 patients in the sitting and lying down positions and under the same respiratory conditions. Results showed that the sitting down position was frequently useful during exploration of suprahepatic veins, and it should be performed whenever visibility in the lying down position in unsatisfactory.

Hepatic Veins↗
PubMed1984

[Evaluation of vascular surgery with digital subtraction angiography. A study of 127 patients].

We have performed digital subtraction angiography (DSA) on 127 patients treated by vascular surgery. This technique was easily and safely performed in outpatients, without any complication. Our experience indicates that DSA is accurate for post operative evaluation in 96% of cases. In digestive arterial surgery, some examinations (3.3%) are insufficient. Distal run off is usually well seen, everywhere, except in kidneys. There is a good correlation between angiographic results and clinical status. However, significant abnormalities were discovered in 5% of cases without any clinical signs. Digital intravenous angiography is a safe and mildly invasive procedure for postoperative evaluation of vascular surgery.

Angiography↗