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A Steudel

Publications and source records attributed to A Steudel.

At least 19 recordsLinked to original sources
PubMed1999

Magnetic resonance imaging to detect bone marrow metastases in the initial staging of small cell lung carcinoma and breast carcinoma.

BACKGROUND: Bone marrow is a common site of metastases in patients with small cell lung carcinoma (SCLC) and female breast carcinoma (FBC). Metastatic bone marrow involvement is found in approximately 50% of SCLC patients and up to 85% of FBC patients at autopsy. Initial staging procedures detect malignant bone marrow lesions in only 2-30% of patients with these tumors. This study was performed to assess whether MRI can improve the detection rate of bone marrow metastases in tumors with a high incidence of skeletal involvement. METHODS: Fifty-two patients with histologically verified SCLC (25 with limited stage disease and 27 with extensive stage disease) and 33 women with FBC were entered into a prospective study. The MRI protocol was comprised of coronal slices in the pelvic region and sagittal slices of the whole spine utilizing a T1-weighted spin echo sequence with a field of view of 50 cm. All patients underwent initial routine diagnostic staging procedures including bone scintigraphy, unilateral crest biopsy, and plain film radiography of suspicious skeletal areas. RESULTS: Only in two SCLC patients, MRI was positive in 25 cases. All SCLC patients with bone marrow lesions histologically verified, diagnosed by crest biopsy (six patients) or by bone scan (seven patients) had the correct diagnosis of metastases by MRI. In addition MRI revealed hypointense bone marrow foci in 14 cases. In contrast, 28 of 33 FBC patients examined during the initial staging procedure showed no evidence of bone marrow involvement. MRI was not superior compared with bone scintigraphy in FBC patients. CONCLUSIONS: The staging results obtained in SCLC and FBC patients are different, although both tumors have a high incidence of bone marrow metastases. It may be assumed that the biologic behavior of these tumors is reflected by the initial bone marrow involvement. Because of its superiority compared with biopsy and bone scan, the authors believe MRI should become an integral part of the initial staging procedures in patients with SCLC. When staging patients with FBC, MRI should be applied only in clinically indicated cases.

Bone Marrow Neoplasms↗
PubMed1999

[MRT, CT and sonography in the preoperative assessment of the primary tumor spread in malignant pleural mesothelioma].

PURPOSE: Evaluation of the diagnostic value of the imaging modalities computed tomography (CT), magnetic resonance imaging (MRI), and thoracic sonography in the preoperative staging of malignant pleural mesothelioma. MATERIALS AND METHODS: The diagnostic accuracy of CT (n = 41), MRI (n = 24), and thoracic sonography (n = 37) were evaluated in 51 patients with histologically proven diffuse malignant pleural mesothelioma. Values of sensitivity, specificity, positive and negative predictive values, and accuracy were calculated for the assessment of the diaphragm, lung, thoracic wall, pericardial wall, myocardium, and (retro)peritoneal space. RESULTS: The accuracy rates for CT were 85%, 98%, 83%, 73%, 71%, and 83%. MRI had an accuracy of 71%, 92%, 71%, 83%, 71%, and 96%, the thoracic ultrasound examinations of 76%, 63%, 51%, 60%, 71%, and 89%. CONCLUSIONS: According to these results CT remains the method of choice in the preoperative assessment of T-stage of malignant pleural mesothelioma. MRI is of nearly the same value, but is not a must. Sonography may be supplementary method for operation planning.

Female↗
PubMed1997

Diagnostic value of MR imaging in comparison to CT in the detection and differential diagnosis of renal masses: ROC analysis.

The aim of this work was to compare MR imaging and CT in the detection of renal masses and in the differential diagnosis between benign and malignant lesions. In 33 patients with 54 renal lesions CT and MR images were evaluated by four readers with regard to tumor detection and characterization using a receiver-operating-characteristics (ROC) analysis. The MRI protocol consisted of a T1-weighted spin-echo (SE) sequence (TR/TE: 300/10 ms) before and after contrast administration and a heavily T2-weighted turbo-SE (TSE) sequence (TR/TE: 5500/150 ms). Az values for the area under the ROC curves for lesion detection were 0.92 +/- 0.04 for CT and 0.91 +/- 0.05 for MRI, respectively, which was not statistically different. The MRI technique was slightly, but not significantly, better than CT in the overall characterization (accuracy in differentiation between benign and malignant) of renal lesions with an Az value of 0.90 +/- 0.05 compared with 0.88 +/- 0.06 for CT. The MRI technique proved to be statistically superior to CT (p < 0.01) in the correct characterization of benign renal lesions. MRI equals CT in the overall detection and differential diagnosis of renal masses. MRI is very helpful for further differential diagnosis of lesions which are equivocal on CT especially in the differentiation between complicated cysts and cystic or hypovascular renal cell carcinoma.

Adult↗
PubMed1997

[Therapy of acute traumatic vascular injuries using covered stents].

PURPOSE: Evaluation of percutaneously implanted covered stents in acute vascular bleeding as therapeutic alternative to conventional surgical treatment. MATERIALS AND METHODS: 8 patients aged 26 to 83 years with acute vascular lesions caused by traumas, and subsequent haemorrhage, were transferred to our department. Because of general inoperability or difficult surgical access, interdisciplinary evaluation favoured an interventional treatment. In 6 patients stents could be placed percutaneously to the aorta, subclavian and iliac arteries. In one case we had to implant three stents into the thoracic aorta. RESULTS: In 7 interventionally treated patients the stents could be placed exactly on the lesions (88%). The bleeding could be stopped immediately in 6 cases (75%). In one patient we had to implant successfully two more stents in reintervention (12%). In another patient the available prosthesis was too short, so that the patient had to be referred to the OR for surgical treatment (12%). There were no complications during the treatment. CONCLUSION: First results in the use of covered stents as interventional treatment of acute vascular lesions are encouraging and may represent a possible alternative to surgical therapy in locally limited bleedings, presupposing that all different types and sizes of industrially produced covered stents are available. Further investigations to compare surgical and interventional techniques are warranted.

Adult↗
PubMed1996

[Magnetic resonance tomography of the kidney: the testing of new pulse sequences and comparison with CT in the differential diagnosis of space-occupying lesions].

PURPOSE: To evaluate new pulse sequences (turbo-spin-echo [TSE] and turbo-field-echo [TFE] sequences) for study protocol optimisation and to assess the role of MRI in the differential diagnosis of renal tumours. METHODS: In six volunteers MRI of the kidney was performed at 0.5 T using a conventional T2 weighted spin-echo (SE) sequence (TR/TE 1800/90 ms) and three different TSE sequences (TR 1800-5000 ms, TE 90-150 ms). Additionally CT and MRI was performed in 34 patients with 41 renal masses. Two readers evaluated both images regarding the differentiation between malignant and benign masses. RESULTS: The pilot study showed that the heavily T2-weighted TSE sequence (TR/TE 5500/150 ms) was superior to other sequences with regard to image quality and differentiation of the corticomedullary junction. In the clinical study malignant tumours were correctly classified with CT and MRI in 86.4% and 95.5% of the cases, whereas the accuracy in the diagnosis of benign lesions of CT and MRI was 73.7% and 89.5%, respectively. CONCLUSION: Using new puls sequences MRI is superior to CT in the differential diagnosis of renal tumours. MRI is superior to CT in the differentiation between complicated cysts and cystic or hypovascular renal cell carcinomas.

Diagnosis, Differential↗
PubMed1995

[Spiral computerized tomography, multiplane transesophageal echocardiography and magnetic resonance imaging in the diagnosis of thoracic aortic dissection].

The aim of this study was the evaluation of spiral computed tomography (Spiral-CT), multiplane transesophageal echocardiography (multiplane TEE) and magnetic resonance imaging (MRI) in the diagnosis of thoracic aortic dissection. 41 patients were examined: 30 with clinically suspected acute aortic dissection (14 Stanford A, 7 Stanford B), 11 with aortic repair (7/11 with persisting distal dissection). In 14 patients there was involvement of the supraaortic vessels. Sensitivity of Spiral-CT, multiplane TEE and MRI in the detection of aortic dissection was 100%, specificity was 100, 92, and 91%. In the assessment of involvement of aortic arch vessels sensitivity was 100, 67, and 60%, specificity was 100, 95, and 90%. The new imaging modalities Spiral-CT and multiplane TEE are equal to MRI in the detection of aortic dissection. In the assessment of the supraaortic branches Spiral-CT is superior to multiplane TEE and MRI and might become the method of choice.

Adult↗
PubMed1995

[DIL vena cava filter. Initial experiences in 15 patients].

DIL filters were permanently inserted through the cubital vein, using a 7-F catheter, in 15 patients and were followed up for six months in 12 patients. One filter could not be opened and 4 others were only partly open. Clinically there were no recurrences of pulmonary emboli. There were no complications from the correctly placed filters. Amongst the 4 incompletely expanded filters, two caused perforation of the cava, in one the cava thrombosed and in another the filter migrated to the bifurcation of the pulmonary artery. It follows that unexpanded filters should not be placed in the cava. Measurements in 10 patients showed the cava reduced to less than 10 mm lumen. In two cases the reduction of lumen was only slight, measuring more than 15 mm. The effect of the reduction in the lumen remains to be compared with that achieved by other filters.

Aged↗
PubMed1995

[MR mammography at 0.5 tesla. I. Comparison of image quality and sensitivity of MR mammography at 0.5 and 1.5 T].

PURPOSE: To determine whether dynamic MR mammography is possible on midfield systems without loss of diagnostic sensitivity when compared to the standard highfield technique. MATERIALS AND METHODS: 42 consecutive patients were examined twice: Once using the standard dynamic 2D gradient echo technique at 1.5 T; a second examination was performed on a 0.5 T system. For the midfield examinations a 3D sequence with optimized T1 contrast was used to compensate for the shorter T1 relaxation times at 0.5 T. Subtraction images were calculated to improve detectability of enhancing lesions. RESULTS: Image quality was comparable on both systems. Mean enhancement of lesions was higher at 0.5 T/3D as compared to 1.5 T/2D (161% versus 112%). In malignant lesions, enhancement at 0.5 T/3D surpassed that at 1.5 T/2D in 88% of cases; average maximum signal intensity increase of cancers was significantly higher at 0.5 T/3D as compared to 1.5 T/2D (183% versus 108% relative to baseline). One satellite lesion of a recurrent carcinoma was detected on the 0.5 T/3D images only. CONCLUSION: A 3D gradient echo pulse sequence can be used to compensate for the T1 shortening effect of the lower field strength. With a 3D sequence, sensitivity of MRM at 0.5 T is even superior to that of the standard 2D highfield technique.

Adult↗
PubMed1995

[Diagnostic imaging in primary hepatobiliary cystadenoma of the liver].

The clinical and radiological findings of 5 patients with a total of 7 hepatobiliary cystadenomas are reported. In all cases sonography and computed tomography were performed, in three cases angiography was carried out, and in one case magnetic resonance imaging was used. On sonography and computed tomography hepatobiliary cystadenomas exhibit relatively typical findings as a multicystic, space-occupying lesion with septation and papillary mucosal nodes; hence the diagnosis can be made preoperatively in most cases. For differential diagnosis, the malignant form, hepatobiliary cystadenocarcinoma has to be considered which can only be distinguished from the benign form by histology.

Adenoma, Bile Duct↗
PubMed1995

[Intra-arterial treatment of therapy-resistant residual tumors of the pelvis].

PURPOSE: Evaluation of intraarterial cancer treatment in recurrent pelvic tumors, which were resistent to other treatment modalities. PATIENTS AND METHODS: Ninety-seven patients suffering from pelvic recurrences originating from bladder (n = 40), rectum (n = 19), cervix (n = 21) oder other organs (n = 17) were treated by intraarterial chemotherapy (111 times) or transcatheter embolisation (52 times). RESULTS: Less than 20% of our patients had remission of the tumor burden but tumor symptoms (especially pain and bleeding) could be controlled in 35 to 87% of the patients. The main complication was a muscle necrosis after intraarterial chemotherapy because of recurrent bladder cancer. CONCLUSION: Intraarterial cancertherapy is a useful procedure for symptomatic treatment of tumor symptoms especially in case of bleeding. Local tumor control can only be achived in a minority of the patients.

Adult↗
PubMed1994

[Hemophiliac arthropathy of the knee joint. Gd-DTPA-enhanced MRI; clinical and roentgenological correlation].

17 patients with hemophilic arthropathy of the knee joint were studied with static and dynamic MRT before and after i.v. bolus injection of Gadolinium-DTPA (0.1 mmol/kg body weight). After contrast enhancement, synovial proliferations exhibited an increase of signal intensity (SI) on FFE and SE images of 47.7% and 37.4% respectively, whereas muscle and fatty tissue, tendons, bone marrow and joint effusion revealed only minor increase in SI. The gradient of signal intensity (ratio SI/time) of pannus was 39.6%/min. Gd-DTPA enhanced MRI studies delineate and quantify the synovial proliferations in hemophilic arthropathy. Dynamic studies in hemophilic arthropathy do not provide qualitative assessment of the inflammatory process.

Adult↗
PubMed1994

[The role of MRT in detecting the cause of therapy-refractory partial complex epilepsy].

MRT is of considerable significance in the investigation of epilepsy because of its ability to render soft tissue contrast for the demonstration of structural lesions. The present retrospective study consists of an analysis of MRT findings in operatively confirmed, circumscribed temporal tumours and in hippocampal sclerosis. The examinations were performed under standard conditions using T1- and T2-weighted spin-echo sequences of the head and coronal T2-weighted gradient-echo sequences of the brain stem. The diagnosis of tumours was extremely accurate (22/23) and specific (18/23) whereas hippocampal sclerosis could not be satisfactorily demonstrated (5/18). The use of intravenous contrast medium did not provide any advantages.

Adolescent↗
PubMed1994

[MR tomography and bone marrow scintigraphy in the screening of skeletal metastases in patients with breast carcinoma].

46 patients with recently diagnosed carcinoma of the breast were included in a prospective comparative study of MRI and bone marrow scintigraphy. The aim of the study was to compare these procedures within a histologically unified patient collective. It was shown that MRI was superior to bone marrow scintigraphy in respect of sensitivity (92% vs 58%) and specificity (97% vs. 85%), although only about three quarters of the marrow spaces are examined by MRI screening. Bone marrow scintigraphy suffered particularly from a relatively high number of false positive findings (haemangiomas, degenerative changes). MRI remains the method of choice for investigating the bone marrow.

Bone Marrow↗
PubMed1994

[The nitinol stent as a palliative measure in inoperable carcinoma of the esophagus and cardia. Possibilities and limitations of the procedure].

Nitinol stents were used in ten patients as palliative treatment for carcinoma of the esophagus and the cardia. Following insertion of the stent the severity of dysphagia decreased on average from 3.2 to 1.5 (on a scale from 0-4). Difficulties with stent opening and passage through the gut were found particularly in the region of metal sutures at esophago-jejunal anastomoses. One stent, which had been obstructed by mucosal folds, had to be removed and replaced. One stent which had been incorrectly placed was extended by introducing a second stent by a coaxial technique. During the period of observation, six patients died after an average of 4.6 months. The palliative effect of the stent lasted on average for eleven weeks. In two patients the tumour grew beyond the stent and in three there was tumour growth into the stent.

Adenocarcinoma↗
PubMed1994

[Evaluation of rapid gradient-echo and turbo-spin-echo sequences in MRT of focal liver lesions using 0.5 tesla].

The value of rapid T1- and T2-weighted fast field (T1-FFE, T2-FFE) gradient-echo sequences and T2 weighted turbo-spin echo (TSE) sequences in the diagnosis of focal liver lesions using 0.5 Tesla was compared with conventional spin-echo sequences (SE). Amongst 88 liver lesions T1-SE sequences showed 98%, T2-TSE sequences showed 92%, T2-SE sequence showed 84%, T1-FFE sequence showed 78% and T2-FFE sequence showed 69%. Direct comparison has shown that TSE sequences are able to demonstrate significantly more lesions (p < 0.05) than T2-SE sequences. Quantitative assessment has shown that the tumor/liver contrast/noise ratio in the T1-SE sequence was 118% higher than in the T1-FFE sequence (p < 0.001). Comparison of T2 weighted sequences has shown that the tumour/liver contrast/noise ratio was 45% higher in the TSE sequence than in the T2-SE and 239% higher than in the T2-FFE sequence (p < 0.001). The results indicate that the TSE sequence should be used instead of the conventional T2-SE sequence because of the reduced time (about 40%), due to improved image quality and increased demonstration rate of liver lesions. Neither T1-FFE nor T2-FFE are suitable, when using moderate field strength, to replace T1-SE or TSE sequences.

Adenocarcinoma↗