Biomedical subjects

A Teifke

Publications and source records attributed to A Teifke.

At least 19 recordsLinked to original sources

PubMed2006

[Second reading of breast imaging at the hospital department of radiology: reasonable or waste of money?].

PURPOSE: To assess the effect of a second diagnostic reading of breast imaging at a university department of radiology. MATERIAL AND METHODS: The diagnostic reports of first readers from different private radiology practices and the reports of second readers from the university department of radiology were compared with the histological results (n = 214) and outcome of follow-ups for 4 years (n = 74) in 236 patients (mean age 55 years). BI-RADS categories were used for this purpose. The initial examinations had been performed because of symptoms (n = 117), early detection outside an organized screening program (n = 102), evaluations following breast cancer therapy (n = 13) and unknown primary tumors (n = 4). In addition, the number of complementary examinations and the influence of a second reading on patient management were evaluated. RESULTS: A total of 140 lesions were malignant and 148 were benign. Of the 288 lesions, 49 % were classified identically in the second reading; 36 % (79/217) of the lesions initially classified as BI-RADS 4 and 5 were downgraded to benign; and 41 % (29/71) of the lesions classified as BI-RADS 1 to 3 were upgraded as suspected of being malignant. The kappa value between the first and second readers was 0.34 with respect to each BI-RADS category separately and 0.18 with respect to categories 1 to 3 (benign) versus 4 and 5 (malignant). A second reading increased the sensitivity from 81 % (114/140) to 96 % (135/140) and the specificity from 30 % (45/148) to 78 % (116/148). Second readers detected 23 additional malignant lesions, changed two lesions correctly classified as malignant to benign categories and caused 6 additional false-positive findings. In all, 38 surgical biopsies could be prevented, one biopsy was erroneously delayed and three unnecessary excisional biopsies were initiated. In the study group, 49 MRI examinations revealed 5 additional malignant lesions and positively influenced surgical planning in 28 patients. In addition to these MRI examinations, 221 patients were examined using ultrasonography, 62 patients using complementary mammography, and 7 using galactography. CONCLUSION: The benefit of a second reading outweighs the expenditure.

Biopsy↗

PubMed2005

[Direct percutaneous radiologic jejunostomy (PR) and duodenostomy: a retrospective analysis].

PURPOSE: To present our experience with direct percutaneous radiologic duodenostomy and jejunostomy (PRJ) for alimentation. MATERIALS AND METHODS: A retrospective study identified 24 patients who had undergone percutaneous jejunostomy or duodenostomy guided by CT and fluoroscopy over a period of 9 years. Whenever possible, the jejunum was inflated with a 5 French diagnostic catheter and jejunopexy was performed using Cope anchors (T-fasteners). A 12 to14 French locking pigtail drain was inserted for alimentation. In 8 patients, percutaneous direct jejunostomy was performed using only fluoroscopy. In 9 patients, both CT and fluoroscopy were used to guide the jejunostomy. In all 7 patients who underwent duodenostomy, a combination of CT and fluoroscopy was used. The reports were reviewed for complications and the technical success rate. The technical success rate was determined. RESULTS: Percutaneous radiologic jejunostomy was attempted in 17 patients and failed in 5 patients. PRJ was successful in all 8 procedures guided by fluoroscopy and in 4 of 9 procedures guided by CT and fluoroscopy. Direct percutaneous duodenostomy guided by CT and fluoroscopy was successful in all 7 cases. There were no procedure-related laparotomies and no mortality related to the jejunostomy. Minor complications were infection of the abdominal wall (n = 1), lingering pain requiring a new jejunostomy (n = 1) and aspiration because of persistent reflux (n = 1). CONCLUSION: PRJ is a safe procedure even in critically ill patients. It is technically difficult and may fail if the jejunum cannot be distended. Percutaneous radiologic duodenostomy and jejunostomy are recommended for prolonged alimentation of malnourished patients following esophageal or gastric surgery.

Critical Illness↗

PubMed2005

[Self-organizing neural networks for automatic detection and classification of contrast (media) enhancement of lesions in dynamic MR-mammography].

PURPOSE: Investigation and statistical evaluation of "Self-Organizing Maps," a special type of neural networks in the field of artificial intelligence, classifying contrast enhancing lesions in dynamic MR-mammography. MATERIAL AND METHODS: 176 investigations with proven histology after core biopsy or operation were randomly divided into two groups. Several Self-Organizing Maps were trained by investigations of the first group to detect and classify contrast enhancing lesions in dynamic MR-mammography. Each single pixel's signal/time curve of all patients within the second group was analyzed by the Self-Organizing Maps. The likelihood of malignancy was visualized by color overlays on the MR-images. At last assessment of contrast-enhancing lesions by each different network was rated visually and evaluated statistically. RESULTS: A well balanced neural network achieved a sensitivity of 90.5 % and a specificity of 72.2 % in predicting malignancy of 88 enhancing lesions. Detailed analysis of false-positive results revealed that every second fibroadenoma showed a "typical malignant" signal/time curve without any chance to differentiate between fibroadenomas and malignant tissue regarding contrast enhancement alone; but this special group of lesions was represented by a well-defined area of the Self-Organizing Map. DISCUSSION: Self-Organizing Maps are capable of classifying a dynamic signal/time curve as "typical benign" or "typical malignant." Therefore, they can be used as second opinion. In view of the now known localization of fibroadenomas enhancing like malignant tumors at the Self-Organizing Map, these lesions could be passed to further analysis by additional post-processing elements (e.g., based on T2-weighted series or morphology analysis) in the future.

Algorithms↗

PubMed2003

Improved artificial neural networks in prediction of malignancy of lesions in contrast-enhanced MR-mammography.

The aim of this study was to evaluate the capability of improved artificial neural networks (ANN) and additional novel training methods in distinguishing between benign and malignant breast lesions in contrast-enhanced magnetic resonance-mammography (MRM). A total of 604 histologically proven cases of contrast-enhanced lesions of the female breast at MRI were analyzed. Morphological, dynamic and clinical parameters were collected and stored in a database. The data set was divided into several groups using random or experimental methods [Training & Testing (T&T) algorithm] to train and test different ANNs. An additional novel computer program for input variable selection was applied. Sensitivity and specificity were calculated and compared with a statistical method and an expert radiologist. After optimization of the distribution of cases among the training and testing sets by the T & T algorithm and the reduction of input variables by the Input Selection procedure a highly sophisticated ANN achieved a sensitivity of 93.6% and a specificity of 91.9% in predicting malignancy of lesions within an independent prediction sample set. The best statistical method reached a sensitivity of 90.5% and a specificity of 68.9%. An expert radiologist performed better than the statistical method but worse than the ANN (sensitivity 92.1%, specificity 85.6%). Features extracted out of dynamic contrast-enhanced MRM and additional clinical data can be successfully analyzed by advanced ANNs. The quality of the resulting network strongly depends on the training methods, which are improved by the use of novel training tools. The best results of an improved ANN outperform expert radiologists.

Algorithms↗

PubMed2002

[Combination of low and high resolution T1-weighted sequences for improved evaluation of morphologic criteria in dynamic contrast enhanced MRI of the breast].

PURPOSE: Presentation of a new protocol for simultaneous acquisition of both low and high resolution T 1 -weighted images of breast lesions for dynamic contrast-enhanced MR mammography. Demonstration of possible diagnostic improvement with representative measurements in patients with suspected breast cancer by adding morphologic parameters from high resolution sequences to the analysis of the signal-time curve. MATERIALS AND METHODS: Dynamic MR imaging was performed with a 1.5 T system (Magnetom SONATA, Siemens Medical Systems, Germany) and the manufacturer's double-breast coil. Coronal T 1 -weighted 3D FLASH sequences (spatial resolution 1.25 x 1.25 mm 2; slice thickness 1.7 mm) were acquired once before and five times after administration of contrast medium (Gd-DTPA, 0.15 mmol/kg) injection. In addition, a high resolution T 1 -weighted 3D-FLASH sequence (spatial resolution, 0.63 x 0.63 mm 2) was obtained before administration of contrast medium and after the third post-contrast low-resolution sequence. Except for the acquisition matrix, all imaging parameters were identical for both 3D pulse sequences. To assure comparison of the measured signal intensities for both T 1 -weighted sequences, calibrating phantom measurements were performed using a dilution series of Gd-DTPA. RESULTS: Phantom measurements demonstrated similar signal intensities and enhancement pattern for both sequences. A combined protocol consisting of both pulse sequences can be employed and does not interfere with the signal-time curve analysis. By measuring one high resolution sequence 3:18 minutes after administration of contrast medium, morphologic features can be evaluated without interference from barely enhancing surrounding tissue. The overall study time is not increased. The improved spatial resolution slightly increases the severity of motion artifacts. CONCLUSION: The new protocol is a clever way to improve the measurement of morphologic features without relevant loss of dynamic information. It is superior to converting the entire investigation to high resolution sequences and does not add any costs by not extending or duplicating the investigation. How much the new protocol can improve the specificity or sensitivity of MR-mammography is currently investigated on a larger patient group.

Breast↗

PubMed2001

[MR mammography of response-control in primary chemo-brachytherapy in BCT-inoperable breast cancer].

PURPOSE: To evaluate (1) if neoadjuvant chemo-brachytherapy interferes with MR imaging, (2) if MR can predict the size of the remaining tumor after therapy and (3) if MR can give prognostic information after the onset of therapy. MATERIALS/METHODS: 14 patients enrolled in a preoperative tumor-reduction protocol (4 cycles of chemotherapy combined with interstitial radiotherapy) were examined by dynamic contrast enhanced MR mammography (1 T, temporal resolution 93 s, spatial resolution 1.9 min, 0.1 mmol/kg GdDTPA), before therapy, after the first two cycles of chemotherapy, after radiotherapy and the third cycle, and after completion of therapy. MR findings were evaluated for (1) artificial enhancement after radiotherapy, (2) correlation of enhancement after therapy with histology and (3) changes in enhancement dynamics after the first 2 cycles. RESULTS: (1) 54% of patients had diffuse enhancement that occurred after radiotherapy but vanished before the end of therapy. (2) 4 patients had complete histological remissions after therapy, 3 had dispersed single tumor cells, 7 had remaining nodular tumor. While MR could not differentiate between complete remission and single tumor cells, it accurately predicted the diameter of remaining nodular tumor, except for one case that showed false-positive enhancement. (3) MR dynamics after the first cycles of chemotherapy could not predict overall response. CONCLUSIONS: MR is an accurate tool in assessing tumor response after neoadjuvant chemobrachytherapy. Negative effects from radiotherapy are only transient.

Adult↗

PubMed2000

[Chloroma (granulocytic sarcoma, myeloblastoma). Clinical aspects and radiological diagnosis].

Six cases of granulocytic sarcoma are presented. A mediastinal chloroma and a tumor of the submandibular gland were observed with two patients as single sign of acute myeloic leukaemia. In one patient a chloroma appeared as first manifestation of acute myeloic leukaemia. Two patients exhibited the tumor as first symptom of a blastic crisis of chronic myelogenous leukaemia (femoral bone, lumbar spine). The sixth patient with a myelodyplastic syndrome showed a chloroma of the breast. Various radiological procedures were applied including plain radiography, MRT, CT and mammography. The results are compared with literature. Principles of therapy were supplemented.

Acute Disease↗

PubMed1999

[Breast cancer screening in surgical patients].

Between January and August 1996, 304 patients of the Department of General and Abdominal Surgery of the University of Mainz who were at least 40 year old, were interviewed about their breast cancer screening behavior. The aim of our investigation was to evaluate the attitude of the target population to breast screening and the value of breast palpation, completed with mammography, during the women's treatment in hospital. 168 (55%) of the interviewed women reported that they had a yearly clinical breast examination in the past. All patients underwent a clinical breast examination. 185 (60%) did not have a mammography in the past or within the past 2 years. These women were offered a mammographic examination during their treatment in the hospital. The investigation revealed one invasive breast cancer. 13 patients had abnormal mammographic or sonographic findings. Our investigation shows, that the compliance of the target population for breast cancer screening is low. Therefore it is necessary to point out the value of breast cancer prevention with clinical examination and mammography also for patients treated in the hospital for an other disease. Every female patient should undergo breast examination. But early detection of breast cancer before micrometastases have occurred is only possible by mammography.

Breast Neoplasms↗

PubMed1996

[Triphasic spiral CT in the diagnosis of liver diseases: comparison with CT arteriography and CT arterio-portography].

PURPOSE: Assessment of the diagnostic efficacy of triphasic spiral-CT scanning (TPS-CT) for liver disease evaluation. CT arteriography (CTA) and CT arterio-portography (CTAP) were used as reference, methods which together have the highest sensitivity for detecting tumours and the perfusion conditions of the liver. MATERIAL AND METHODS: 50 TPS-CT and CTA/CTPA were performed in 49 patients. After an initial examination without enhancement the first scan was initiated 15-25s after the peripheral bolus injection of contrast medium, the second after an interscan delay of 20-25s. By this means the liver was imaged in different phases of perfusion. In the course of the CTA/CTPA-exam the imaging was carried out after selective, intraarterial application of contrast agent. RESULTS: The differentiation of the perfusion phases succeeded in 90% of the patients. When compared with standard CT, which images only the portal venous phase, the new technique, which additionally shows the arterial perfusion, accomplished an increase in sensitivity for hypervascular lesions (51% vs. 60%). Yet in comparison with CTA/CTPA fewer lesions could be detected (87 vs. 138). Furthermore, by documenting the contrast agent kinetics, characterisation of the lesion was also facilitated. CONCLUSION: DPS-CT is a valuable additional tool for imaging the liver, even if the information yield is less when compared to CTA/CTPA.

Adult↗

PubMed1995

[Intrarenal color Doppler ultrasound for exclusion of renal artery stenosis in cases of multiple renal arteries. Analysis of the Doppler spectrum and tardus parvus phenomenon].

PURPOSE: To diagnose possible renal artery stenosis especially in case of multiple renal arteries by intrarenal colour-coded Duplex sonography. METHODS: In 50 hypertensive patients lobar and interlobar arteries were looked for at 3 different levels. Analysis included the determination of the early systolic acceleration time and the assessment of the Doppler waveform, especially the "tardus-parvus" phenomenon. Intraarterial angiography was performed in all patients the next day. RESULTS: In 48/50 patients the sonographic investigations were sufficiently evaluable. Angiography showed haemodynamically relevant stenosis in 13 patients, in 4 patients bilaterally. In 21 patients (42%) multiple renal arteries were found. Sensitivity and specificity in the diagnosis of renal artery stenosis was 77% respectively 46% (threshold value > or = 0.120 s). In 10/17 angiographically verified haemodynamically relevant renal artery stenosis a change of the Doppler waveform was noted; sensitivity in the diagnosis of renal artery stenosis was 69%, specificity 90%. CONCLUSION: Intrarenal colour-coded Duplex sonography cannot be recommended as a screening tool for renal artery stenosis.

Adult↗

PubMed1994

[Spiral computerized tomography of the breast].

AIM: To evaluate the use of spiral CT in the diagnosis of breast lesions. MATERIAL AND METHODS: 93 female patients with suspicious or uncertain mammographic findings were examined by CT before and after contrast enhancement according to the following practical method: table movement, 6 mm/s, slice thickness 6 mm, increment 4 mm, contrast 200 ml, injection rate 3 ml/s, scan start 50 s after the beginning of the injection. Histological confirmation was present in 85 patients. RESULTS: All 44 invasive carcinomas were recognised. They were characterised by intensive focal contrast uptake. Only 2 out of 7 intraductal carcinomas were not shown by CT. 36 out of 38 benign lesions were correctly diagnosed. 2 out of 11 fibroadenomas showed strong enhancement and were incorrectly diagnosed. The examinations provided valuable additional information compared to mammography and sonography. CONCLUSION: Spiral CT is very useful for elucidating problems in the diagnosis of breast lesions. Its advantages consist in the speed of the method, comfort for the patient, absence of movement artifacts, easy standardisation and wide applicability.

Adenocarcinoma, Mucinous↗

PubMed1994

[Extrapulmonary manifestation of sarcoidosis in the breast].

Sarcoidosis is, pathologico-anatomically speaking, a granulomatous disease that can involve almost any organ. However, a histologically confirmed involvement of the mammary gland after exclusion by differential diagnosis of granulomatous mastitis and mycobacterial or fungal sonographic and mammographic image would rather suggest a fibroadenoma of the breast. However, a malignant process such as for instance a mucinous carcinoma of the breast should always be excluded by differential diagnosis, especially if there are concomitant general symptoms of disease.

Aged↗

PubMed1993

[The safety belt: effects on injury patterns of automobile passengers].

Since 1984 the law concerning safety belts has been implemented; this paper deals with the findings in 386 victims of motor accidents who were x-rayed between 1981 and 1989. Minor injuries have been ignored. The number of passengers wearing belts increased by 30% after 1984. The number of passenger injuries did not decrease. Injuries directly caused by the belts included a small number of fractures of clavicles, the sternum and ribs and one pelvic fracture, one serious abdominal injury with tearing of the mesenteric artery and one ruptured spleen. An indirect result of wearing seat belts was a marked increase in cervical whiplash injuries and some increase in thoracic vertebral fractures. None of the belt induced injuries proved fatal. Amongst those using seat belts there was a significantly lower fatality rate and injuries causing prolonged disability. In particular, using seat belts, serious injuries to the skull and brain were reduced by 80%. Similarly injuries to the abdomen, the odontoid, pelvis and hip joint were greatly reduced. The advantages of wearing a seat belt greatly outweigh the disadvantages.

Accidents, Traffic↗

PubMed1992

[Lobular carcinoma of the breast in magnetic resonance tomography. A case report].

The invasive lobular carcinoma of the breast, the incidence of which is 10-15 per cent, occupies a special position in respect of histological differentiation and biological behaviour. No MR signal enhancement was seen after contrast medium application in the tumoral tissue in the case described here, namely, an invasive lobular carcinoma of the breast of 2 cm size. Hence, it is not always possible to exclude with absolute certainty the presence especially of an invasive lobular carcinoma of the breast in the absence of contrast medium uptake.

Breast Neoplasms↗

PubMed1992

[The disease factor of scapholunate dissociation].

Scapholunate dissociation is the most common form of instability of the wrist. Its occurrence has been consistently attributed to previous trauma and is supposed to be treated by operation. In the present paper we show that chronic bilateral scapholunate dissociation without any symptoms is not rare. In two years we accidently found four cases with bilateral scapholunate dissociation. In such cases an operation cannot be successful. Therefore, we recommend that a specific trauma should be checked very carefully and roentgenograms of both wrists done.

Carpal Bones↗

PubMed1991

[Ambulatory angiography].

Outpatient angiography is justified in selected cases; patients with risk factors must be excluded. The examination should be performed as atraumatically as possible. After angiography, the patient should be kept under observation for at least 6 hours, since most complications occur during or shortly after the intervention. Only vary rarely do complications develop after the patient has been discharged, the most serious being late hemorrhage. Facilities for rapid treatment must be provided.

Ambulatory Care↗

PubMed1991

[Interventional angiology in the area of the thigh. Percutaneous balloon dilatation, new procedures of recanalization, stents].

The major technique of interventional angiology of the arteries of the thigh is percutaneous balloon dilatation (angioplasty). In the case of short stenoses and occlusions, the primary results and long-term success of these techniques are very good. In order to be able to successfully treat long, highly calcified, eccentric and fresh lesions using the percutaneous approach, numerous new procedures have been developed. These include local fibrinolysis, aspiration of thromboembolic material, ablation of atherosclerotic plaques using an endovascular knife, the drilling open of occlusions, the use of the laser, and implantation of vascular endoprostheses.

Angioplasty, Balloon↗

PubMed1991

[Nonsurgical recanalization of tibial arteries. Balloon dilatation, local fibrinolysis and aspiration embolectomy].

To date, percutaneous angioplasty has only rarely been employed to recanalize arteries in the lower leg. In almost all such patients, the limb has been at risk of being amputated. Since the introduction of special thin-caliber balloon catheters and concomitant drug therapy to prevent vascular spasms and thromboses, results have been markedly improved. In the case of fresh occlusions, local fibrinolysis with percutaneous aspiration embolectomy is employed.

Angioplasty, Balloon↗