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Biomedical subjects

S Feuerbach

Publications and source records attributed to S Feuerbach.

At least 127 records · Page 7Linked to original sources
PubMed1996

[Contrast medium administration in spiral computed tomography: the results of a consensus conference. Institute for Radiodiagnosis, Regensburg].

The rapidity of spiral (helical-) computed tomography requires new protocols for i.v. contrast media administration. Flow rate, volume and delay are discussed controversially in the literature. Hence, a consensus meeting was initiated. In this meeting, problem related questions were designed, discussed and answered using a digital vote system. Spiral-CT-technology was found to be the ideal examination technique for thorax, liver, pancreas, kidney and the retroperitoneal space with an overall agreement between 89 and 97%. The exclusive use of nonionic contrast media and power injectors was recommended by 100% of the participants. More than 90% of the contributors did not accept native scans only for examinations of the neck, thorax, liver, pancreas, kidney and the retroperitoneal space. Regarding volume, flow rate, delay and physical CT-parameters the agreement laid between 50 and 100%. The meeting concluded that randomised controlled studies should be performed to evaluate detailed contrast media protocols for helical CT.

Berlin↗
PubMed1995

Focal white-matter lesions in brain of patients with inflammatory bowel disease.

Inflammatory bowel diseases are often associated with extra-intestinal manifestations, such as arthritis and iritis/uveitis. Using magnetic-resonance imaging we found hyperintense focal white-matter lesions in the brain in 20 of 48 (42%) patients with Crohn's disease, in 11 of 24 (46%) patients with ulcerative colitis, but in only 8 of 50 (16%) healthy age-matched controls (relative risk [95% CI] vs controls 2.6 [1.3-5.3] and 2.9 [1.3-6.2], respectively). These findings may represent another extra-intestinal manifestation of inflammatory bowel disease.

Adult↗
PubMed1995

[Accuracy of artificial neural networks in radiological differential diagnosis of solitary bone lesions].

PURPOSE: To evaluate the usefulness of artificial neural networks (ANN) for differential diagnosis of bone tumours and tumour-like lesions. MATERIAL AND TECHNIQUE: Different ANN were designed to distinguish between 23 types of bone lesions and to classify these lesions as benign or malignant on the basis of 28 items of clinical and radiographic information. Training of the feed-forward networks with a back-propagation algorithm was performed using either 46 hypothetical examples or 115 real cases. The data base for testing the different ANN included 115 clinical cases (5 cases for each possible diagnosis), which were different from the examples used for training. The decision performance of the ANN was evaluated by means of ROC analysis. Results were compared to the performance of an experienced radiologist. RESULTS: The radiologist was significantly superior in finding the correct diagnosis (69/115 vs. 41/115; p < 0.001) and the area under his ROC curve (referring to the discrimination between benign and malignant lesions) was slightly larger than that of two different ANN (0.973 vs. 0.945 and 0.973 vs. 0.962 resp.; differences not significant). CONCLUSION: ANN may be potentially useful to distinguish between malignant and benign lesions, but their performance in differentiating between 23 diagnoses must be improved significantly.

Algorithms↗
PubMed1995

Cerebral metabolite patterns in dialysis patients: evaluation with H-1 MR spectroscopy.

PURPOSE: To analyze metabolic changes in the brain of patients undergoing dialysis. MATERIALS AND METHODS: Sixteen patients undergoing hemodialysis, 10 patients undergoing continuous ambulatory peritoneal dialysis (CAPD), and 42 healthy volunteers underwent magnetic resonance (MR) spectroscopy and MR imaging. Spectra were obtained from one occipital gray matter voxel and one parietal white matter voxel. Changes in N-acetylaspartate (NAA), choline (Cho), myo-inositol and glycine (Myo), and creatine (Cr) were analyzed and the results presented as ratios, with Cr as the reference. RESULTS: Three abnormalities were observed in the spectra of the hemodialysis patients: (a) significant elevation of the Cho/Cr ratio in gray matter, (b) significant elevation of the Myo/Cr ratio in gray matter, and (c) significant reduction of the NAA/Cr ratio in gray and white matter. The strongest metabolic alterations were found in cortical gray matter. In CAPD patients, only gray matter Cho/Cr ratio was significantly elevated. An increased frequency of focal white matter lesions was observed on MR images in the dialysis patients. CONCLUSION: Proton MR spectroscopy is useful for in vivo monitoring of metabolic alterations in the brain due to chronic dialysis.

Adult↗
PubMed1995

High-resolution SPECT of the temporomandibular joint in chronic craniofacial pain disorders: a pilot study.

Chronic craniofacial pain disorders commonly cause physicians diagnostic difficulties. The purpose of this study was, on one hand, to detect pathological focuses of the craniofacial skeleton using a new system of high-resolution single photon emission computertomography (SPECT), and on the other hand, to compare the results with those obtained via high-field magnetic resonance imaging (MRI) as far as temporomandibular joint affections are concerned. SPECT can be regarded as a supplementary diagnostic mean for patients displaying the symptoms of chronic craniofacial pain disorders, especially in cases where clinical and paraclinical investigations do not coïncide or which are refractory to treatment, not least to differentiate between somatic and psychogenic causes, respectively.

Adult↗
PubMed1994

[Indications for and pertinence of 3D tomodensitometry in panfacial fractures].

Successful treatment of panfacial fractures is dependent on precise clinical and radiological examinations. However, the complexity of fracture lines accounts for the problems and inadequacies of plain films. Three-dimensional CT-reconstruction is recommended to help the maxillofacial surgeon to conceptualize the overall injury. Subsequently, a case involving complex panfacial fractures is presented and the potential value of three-dimensional computed tomography is discussed.

Facial Bones↗
PubMed1992

[The endosonographic staging of pancreatic carcinoma].

Endoscopic ultrasound (EUS), conventional ultrasound (US), computed tomography (CT) and angiography were compared in their assessment of local resectability in 35 consecutive patients (19 men, 16 women; mean age 49.8 [42-821] years) with non-metastatic carcinoma of the pancreas. The findings were made prospectively and independently of each other. EUS proved to be superior to transabdominal US and to CT in the diagnosis of tumour infiltration of the portal and splenic veins. For the portal vein the sensitivity was 93% by EUS, 14% by US and 36% by CT. Corresponding figures for the splenic vein were 92%, 39% and 69%. EUS was markedly superior to angiography in the diagnosis of portal vein involvement (sensitivity of 93% and 36%, respectively), but the two methods had similar sensitivity regarding splenic vein infiltration (92 and 100%). Tumour involvement of the coeliac trunk was diagnosed with higher sensitivity angiographically (86%) than by EUS (57%), CT (71%) or US (29%). Regarding T and N staging, EUS was superior to both US and CT. These data indicate that EUS is the most accurate method for local tumour staging of potentially resectable pancreatic carcinoma. It can replace angiography in the diagnosis of portal vein infiltration.

Adult↗
PubMed1992

Staging of pancreatic and ampullary carcinoma by endoscopic ultrasonography. Comparison with conventional sonography, computed tomography, and angiography.

In a prospective study, endoscopic ultrasonography was compared with transabdominal ultrasonography, computed tomography, and angiography in 60 consecutive patients with pancreatic (n = 46) and ampullary (n = 14) cancer considered to be candidates for surgery. The diagnostic value of these imaging procedures in determining local resectability was assessed. The diagnosis of ampullopancreatic malignancy was made by operation (n = 40) or puncture/biopsy (n = 20). In the 40 patients who underwent surgery, endoscopic ultrasonography was significantly superior to abdominal ultrasonography and computed tomography in determining tumor size and extent and lymph node metastases of pancreatic and ampullary cancer. Furthermore, involvement of the portal venous system as judged by histopathology or surgical exploration was correctly assessed by endoscopic ultrasonography in 95%, whereas angiography (85%), computed tomography (75%) and abdominal ultrasonography (55%) were less sensitive. Of 11 cases of portal venous infiltration found at surgery, endoscopic ultrasonography correctly predicted 10, abdominal ultrasonography only 1, computed tomography 4, and angiography 5 (P less than 0.05 for all three comparisons). Twenty patients did not undergo surgery for different reasons: of those, 9 patients were excluded from operation because of portal venous involvement as shown by angiography. Endoscopic ultrasonography detected portal venous invasion in all these cases. In contrast to the venous system, arterial encasement was less reliably detected by endoscopic ultrasonography. In conclusion, endoscopic ultrasonography is the most effective single imaging procedure for local tumor staging in pancreatic and ampullary cancer. Thus, endoscopic ultrasonography will improve the assessment of tumor resectability and further decrease the need for explorative laparotomy.

Adult↗
PubMed1991

[Granular cell tumor (Abrikossoff tumor) in the digestive and respiratory tracts--two new observations].

Granular cell tumor is one of the rare neoplasms of presumptively neural origin of the alimentary and respiratory tracts. Two new endoscopically and histologically confirmed observations are presented. The radiological appearance (conventional radiography and x-ray computed tomography) is described in detail and compared with the findings published in the literature.

Digestive System Neoplasms↗
PubMed1990

[Endosonographic diagnosis of pancreatic tumors].

140 patients (72 men, 68 women; mean age 57 [26-83] years) with suspected pancreatic tumours were investigated by endoscopic ultrasound (EUS) and also by conventional ultrasound, computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP). The EUS scans were performed with an echo-endoscope in the descending part of the duodenum (for the head of the pancreas) or in the stomach (for the body and tail). The definitive diagnosis or exclusion of a pancreatic tumour (malignant n = 85, benign n = 4, inflammatory n = 23, no tumour n = 28) was made at operation (n = 63), by needle biopsy (n = 35), at necropsy (n = 4) or by clinical follow up (n = 38, mean 10.5 months). The sensitivity and specificity of endoscopic ultrasound (99% and 100%) were superior to the results given by conventional ultrasound scans (71% and 39%), CT (82% and 46%) and ERCP (89% and 64%). This was also true of small tumours of 3 cm or less (EUS 100%, conventional ultrasound 57%, CT 68% and ERCP 89%). However, the differential diagnosis between malignant and inflammatory masses in the pancreas was not feasible by endoscopic ultrasound, either prospectively (detection rate 69%) or by comparative analyses of echo structure. Endoscopic ultrasound appears to be a valuable aid to the diagnosis or exclusion of pancreatic tumours. When conventional ultrasound and CT give negative or doubtful results it can be used in conjunction with or instead of ERCP to confirm the diagnosis.

Adult↗
PubMed1989

[CT-guided biopsy: methods, results and complications].

Percutaneous CT-guided biopsies were carried out in 350 patients; on 291 occasions, 14- or 18-gauge and, on 59 occasions, an 0.95 mm cutting biopsy cannula was employed. Using the 14- and 18-gauge needles, a histological diagnosis was possible in 191 cases, a sensitivity of 82.7%. The 0.95 mm cannulas proved successful in 39 of the 59 punctures, producing a markedly lower sensitivity of 66.2%. The most common cause of an incorrect biopsy with large needles was bad position of the needle, whereas the small needles provided inadequate material. Complications which, however, did not require treatment, occurred in 5 patients (1.4%).

Biopsy, Needle↗