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Biomedical subjects

A Rieber

Publications and source records attributed to A Rieber.

At least 91 records · Page 5Linked to original sources
PubMed1995

[First clinical experience with a new nitinol stent in the biliary system].

PURPOSE: To evaluate the clinical usefulness of a new nitinol biliary stent (Memotherm) in patients with malignant biliary obstruction. 32 self expanding nitinol stents were applied in 17 patients. The following parameters were investigated: Difficulty of placement, lateral stability and patency over an observation time between 3 weeks and 11 months. RESULTS: In 29/32 stent application could be performed with high precision. In 3/32 we observed a displacement about 1 cm--according to the optimal stent position. Stent shortening was about 5 mm in 31/32 stents, secondary shortening only occurred in one patient with primarily distracted stent design. Lateral stability was sufficient in 21/25 stenoses with the consequence that dilatation was only performed in 4 cases. Average stent patency was 4.8 months, the average survival 5.1 months. Because of his special design, this stent may not be used for a stenosis with angulation higher than 90 degrees. CONCLUSION: Basing on a small calibre introducing system, easy placement, predictable minimal shortening and good lateral stability, the Memotherm seems an interesting alternative to other metal stents.

Alloys↗
PubMed1995

CT and MR imaging of adrenal hemangioma. A case report.

PURPOSE: Cavernous hemangiomas of the adrenal gland are rare, and we here describe CT and MR features of an additional case including delayed contrast CT. RESULTS: On CT, the tumor appeared as a well-delineated mass. Fatty areas and calcifications were seen. On delayed contrast CT, a progressive enhancement from the periphery to the center of the tumor was noticed, similar to the contrast enhancement of liver hemangiomas. In T1-weighted MR images, a hypointense tumor with a central stellate area of hypointensity was found. The tumor had a predominantly peripheral contrast enhancement. CONCLUSION: CT and MR findings of adrenal hemangiomas are in some cases similar to those of liver hemangiomas. A tumor resection must be considered if the tumor changes in appearance or size.

Adrenal Gland Neoplasms↗
PubMed1994

Pulmonary nodules in spiral volumetric and single slice computed tomography.

Single slice acquisition of conventional CT and volume scanning of spiral volumetric CT are compared in terms of detection and assessment of pulmonary nodules. Spiral CT is supposed to be superior to conventional CT in detecting all lung nodules by scanning the complete lung volume, while conventional CT may miss nodules due to inconsistent levels of inspiration for single slices. Different technical procedures of spiral CT may change the imaging of nodules and other findings. Fifty-two patients with known or suspected lung nodules were examined by conventional CT and spiral CT. Number and size of lung nodules and imaging of other pulmonary findings were registered independently by two radiologists. Spiral CT showed 15 lung nodules not seen on conventional CT, and missed one nodule. Spiral CT imaging of nodules was superior in some cases (characterisation of benign nodules) because complete scanning provided more information than conventional CT. It was worse in some cases (small nodules, fibrosis, small pleural effusion) due to the greater partial volume effect and less mAs. Technically improved spiral CT with longer scanning facilities and a 180-degree algorithm may be able to replace conventional CT for this indication.

Humans↗
PubMed1994

[Fibrolamellar carcinoma].

Fibrolamellar carcinoma (FL-Ca) is a primary malignant liver tumor at unknown etiology, without cirrhosis and usually without an increase at tumor markers, which occurs mainly in young patients. As it can simulate malignant and benign tumors, particularly FNH, diagnosis is difficult. Ultrasound and angiography show mostly uncharacteristic features. The highest specificity has CT, if calcifications are present, because these calcifications in a tumor similar to FNH are pathognomonic for FL-Ca. In MRI the central scars of FL-Ca and FNH have a different signal intensity in T2-weighted images, so that MRI becomes more and more important in the differential diagnosis to FNH.

Carcinoma, Hepatocellular↗
PubMed1994

[Diagnosis of fibrolamellar cancer].

A fibrolamellar carcinoma (FL-Ca) is a primary malignant tumor of the liver of unknown etiology, without cirrhosis and usually without an increase in tumor markers; it occurs mainly in young patients. As it can simulate malignant and benign tumors, particularly focal nodular hypoplasia (FNH), the diagnosis is difficult. Ultrasound and angiography show mostly uncharacteristic features, so ultrasound only has to ascertain that the tumor is there. Angiography can reveal vascular infiltrations and assess the resectability of the tumor, but diagnosis of FL-Ca is not always possible with angiography. CT has the highest specificity if calcifications are present, because calcifications in a tumor similar to FNH are pathognomonic for FL-Ca. By means of hepatobiliary functional scintigraphy FNH can be excluded. MRI seems to be important in differentiating the tumor from FNH, because the central scars of FL-Ca and FNH--if present--have a different signal intensity in T2-weighted images. The histological diagnosis of FL-Ca is also difficult. In patients with resectable tumors or prior to liver transplantation, an operative biopsy should be obtained to verify the diagnosis. In non-resectable tumors sonographic guided biopsy is justified.

Adult↗
PubMed1993

[Modified implantation of a Wallstent in bile duct obstruction].

The self-expanding Wallstents are increasingly applied in malignant biliary obstructions. The deployment of the stent from the covering membrane is a relatively complicated mechanism susceptible to trouble. Sometimes the deployment of the stent from the catheter fails and the incompletely deployed stent has to be removed and rejected. In a total of 9 patients with malignant bile duct obstruction 11 deployed stents were inserted in a technical modification over a 10 F sheath. The proposed technique has the advantages of a reduction of costs and of an exact placement of the stent.

Aged↗
PubMed1993

[Percutaneous intraductal ultrasound of the bile ducts].

Miniaturization of ultrasound probes (6 F, 20 MHz) enables to perform intraluminal sonography of the bile duct in patients in whom a percutaneous transhepatic access has been achieved for diagnostic or therapeutic reasons. Initial experiences in 13 patients with malignant bile duct obstruction and in 8 patients with benign bile duct disease are described. Intraluminal ultrasound displays the normal anatomy and pathologic processes of the bile ducts and reveals information on therapeutic procedures within the bile ducts. Malignant tumors and benign strictures can be differentiated in most cases. In malignant disease, this diagnostic method improves the difficult staging of bile duct tumors and gives information on tumor extension, infiltration of adjacent tissues and vessels, and lymph node enlargement. The limited penetration depth of 1.5-2.0 cm creates problems in the staging of tumors particularly at the hepatic hilum. The procedure is simple and devoid of risks, but requires some refinements and improvements to attain a wider use in different clinical problems.

Adult↗
PubMed1992

[Percutaneous transhepatic cholangioscopic color laser lithotripsy in bile duct calculi].

Tunable dye laser lithotripsy is an effective and low risk treatment in patients with bile duct stones in which transpapillary maneuvers failed. The percutaneous approach allows to introduce small caliber endoscopes (10.5 F) to fragment the calculi under vision. This technique was evaluated in 8 patients who had undergone a biliodigestive anastomosis or in whom the biliary calculi could not removed by standard retrograde treatment. Laser lithotripsy resulted in sufficient fragmentation in 7 patients. Bile duct clearance proved to be a particular problem with the percutaneous access. When a retrograde sphincterotomy is not possible an antegrade papillotomy must be attempted under fluoroscopic guidance. In bile duct strictures the implantation of expandable stents facilitates the passage of fragments and may prevent recurrent stricture and development of new stones.

Aged↗
PubMed1992

[Differential diagnosis of angiodysplasias using angiography and CT with special reference to the MR tomographic aspects].

The basic prerequisite for a rational therapy of angiodysplasia is differentiated diagnostics, especially the differentiation between arteriovenous malformations, haemangiomas, and venous malformations. Angiography reveals the arterialisation, arteriovenous fistulas, CT infiltrations of bone and soft-tissue. MRT demonstrates completely the extent of haemangiomas because of its bright signal intensity in the T2-weighted images. Hence, differentiation of malignant vessel tumours and malformations with rapid blood flow is possible, because the signal intensity is much lower in MRT. The three supplementary methods allow a correct diagnosis of angiodysplasia.

Angiodysplasia↗
PubMed1991

Magnetic-resonance tomography of an inflammatory aneurysm.

An inflammatory aneurysm is defined as an abacterial special type of atherosclerotic aneurysm. The macroscopic characteristics are: a porcellaneous appearance, excessive thickening of the aortic wall, and perianeurysmal adhesions. Chronic inflammatory infiltrations, which are localized in the adventitia, can be found via microscopy. With computed tomography the thickening of the aneurysmal wall can be demonstrated best. The appearance of an inflammatory aneurysm in magnetic-resonance tomography is described in one patient.

Aged↗