PubMed Health⌕ Search

Biomedical subjects

H J Brambs

Publications and source records attributed to H J Brambs.

At least 19 recordsLinked to original sources
PubMed2005

[The "EVA" Trial: Evaluation of the Efficacy of Diagnostic Methods (Mammography, Ultrasound, MRI) in the secondary and tertiary prevention of familial breast cancer. Preliminary results after the first half of the study period].

PURPOSE: To investigate the respective diagnostic accuracies of the different breast imaging modalities, i. e., mammography (Mx), high-frequency breast ultrasound (US), and dynamic contrast-enhanced breast (MRI) regarding the early diagnosis of familial (hereditary) breast cancer. MATERIALS AND METHODS: A prospective, non-randomized controlled clinical multi-center trial is performed at 4 academic tertiary care centers in Germany (Ulm, Munchen/Grosshadern, Munster and Bonn) for a total period of 4 years, sponsored by the German Cancer Aid. The protocol consists of semiannual clinical visits and breast ultrasound, and annual bilateral two-view Mx, US and MRI. Imaging studies were first analyzed independently, then Mx was read in conjunction with US, followed by Mx combined with MRI, and finally, all three imaging modalities were read in synopsis. We present the concept and first results of this trial. RESULTS: So far, 748 screening rounds are available for analysis in 613 women. A total of 12 breast cancers have been identified, with 11/12 cases in the pTis or pT1/N0 stage. The mean size of detected invasive cancers was 7 mm. A total of 19 benign lesions were biopsied due to false-positive imaging diagnoses. The breast cancer detection rates were: Mx: 5/12 (42 %), US 3/12 (25 %), MRI 10/12 (83 %), and the positive predictive values: Mx 5/17 (29 %), US 3/15 (30 %), and MRI 10/23 (43 %). CONCLUSION: The preliminary data suggest that early diagnosis of familial breast cancer is feasible by intensified surveillance, in particular with the addition of MRI.

Adult↗
PubMed2005

A retrospective evaluation of patient acceptance of computed tomography colonography ("virtual colonoscopy") in comparison with conventional colonoscopy in an average risk screening population.

PURPOSE: To evaluate patient acceptance of computed tomography (CT) colonography compared with conventional colonoscopy by means of a self-assessed questionnaire. MATERIAL AND METHODS: Four-hundred-and-one patients with valid address information from our patient collective were preselected. Patient acceptance was evaluated retrospectively using a self-assessed questionnaire. The patients underwent CT colonography in our institution using 4x or 16x multi-detector row (MDR) CT. Two-hundred-and-forty-six patients returned a completed questionnaire, 157 of these indicating that they had undergone both virtual and conventional colonoscopy. RESULTS: One-hundred-and-twenty (76.4%) of the 157 patients would undergo another CT colonography if necessary, while only 14 patients would not. One-hundred-and-sixteen (73.9%) patients favored the actual examination procedure of CT colonography (P<0.0001), while only 6.4% preferred the conventional method. Preparation prior to CT colonography was experienced as more convenient than preparation prior to conventional colonoscopy (52.2% versus 14%). CONCLUSION: CT colonography was preferred in terms of both preparation and the actual procedure itself.

Adult↗
PubMed2004

[Non-invasive, multi detector row (MDR) CT based computational fluid dynamics (CFD) analysis of hemodynamics in infrarenal abdominal aortic aneurysm (AAA) before and after endovascular repair].

PURPOSE: Simulation, description and analysis of dynamic pressure in infrarenal abdominal aortic aneurysms (AAA) before and after endovascular repair. MATERIALS AND METHODS: During March 1996 and May 2001, 13 patients with AAA underwent endovascular treatment. The MDR-CT scans of these patients were used for the non-invasive analysis of the hemodynamics in the aorta with CFD software before and after endovascular repair. One pre-interventional and three post-interventional CT scans were analyzed for each patient. RESULTS: Compared to the pre-interventional simulation, endovascular treatment led to an average dynamic pressure decrease of 1057 Pa in 10 of 13 patients. During the subsequent course, the median of the dynamic pressure decreased in 8 of 13 patients. Vulnerable regions initially identified as high-pressure regions, like the docking area or the second stent limb, adapted to the pressure in the surrounding tissue in the course of time. CONCLUSION: CFD-based blood flow simulation offers the opportunity to analyze dynamic pressure in AAA before and after endovascular repair and allows a prognostic statement as to the possible homogenization of the pressure in abdominal stent-grafts.

Aortic Aneurysm, Abdominal↗
PubMed2002

Pre-operative staging of invasive breast cancer with MR mammography and/or PET: boon or bunk?

This study compared pre-operative staging with MR mammography (MRM) and positron emission tomography (PET) in patients with clinically suspected breast cancer according to the Breast Imaging Reporting and Data System, category 5. A total of 43 patients with breast cancer were examined. MRM included both T(2) weighted turbo spin echo sequences and T(1) weighted gradient echo sequences (three-dimensional fast low angle shot) before and after application of gadolinium-DPTA. All patients then underwent examination with a modern full-ring PET scanner following injection of fluorodeoxyglucose. We evaluated the efficacy of these methods in the diagnosis of primary tumour, contralateral carcinomas, bifocal, trifocal or multifocal disease, as well as non-invasive cancer portions and tumour size. Determination of patients' N-status was only attempted using PET. All findings were validated by histological examination. MRM was slightly superior to PET in several areas, such as in the respective methods' sensitivity and specificity. Sensitivities for MRM and PET were: 100% vs 93.0% in diagnosis of the primary tumour; 100% vs 100% in diagnosis of contralateral carcinomas; and 95.2% vs 92.5% in diagnosis of bifocal, trifocal or multifocal disease. Specificities for MRM and PET were: 100% vs 97.5% in diagnosis of contralateral carcinomas; and 96.8% vs 90.3% in diagnosis of bifocal, trifocal or multifocal disease. Non-invasive cancer portions and tumour sizes were equally well determined with both methods. The sensitivity of PET for detection of lymph node involvement was 80% and specificity 95%. MRM and PET were superior to conventional methods in nearly all areas studied; the findings of one or both of the methods impacted positively on patients' surgical treatment in 12.5-15% of cases. Pre-operative MRM and/or PET can have a positive influence on surgical treatment planning. Therefore, it appears useful to perform pre-operative staging with MRM or PET in these patients.

Adult↗
PubMed2001

Is a preoperative multidiagnostic approach to predict surgical resectability of periampullary tumors still effective?

BACKGROUND: Multimodality staging is recommended in patients with periampullary tumors to optimize preoperative determination of resectability. We investigated the potency of currently used diagnostic procedures in order to determine resectability. METHODS: Ninety-five consecutive patients with periampullary tumors prehospitally staged resectable underwent preoperative diagnostic tests: helical-computed tomography (CT) with maximum intensity projection of arterial vessels (MIP), magnetic resonance imaging (MRI), magnetic resonance cholangiopancreaticography (MRCP), endoscopic ultrasonography (EUS), endoscopic retrograde cholangiopancreaticography (ERCP), digital subtraction angiography (DSA), and positron emission tomography (PET). Diagnoses were verified by surgery and histopathology. RESULTS: In 45 patients with benign and 50 patients with malignant periampullary tumors sensitivity for tumor diagnosis was 89% to 96% in CT, MRI, EUS, and PET. Small tumors were best diagnosed by EUS (100%). Diagnosis of malignancy was made with 85% (EUS), 83% (CT), 82% (PET), and 72% (MRI) accuracy. Arterial vessel infiltration was best predicted by CT/MIP with an accuracy of 85%. For venous vessel infiltration MRI reached 85% accuracy. Accuracy rates for local nonresectability were 93% (EUS), 92% (MRI), and 90% (CT). Two and 4 of 8 patients with distant metastases were identified by CT and PET, respectively. The correct diagnosis of malignancy and determination of resectability was made by CT in 71% and by MRI in 70%. Biliary stenting reduced accuracy of CT diagnosis of malignancy from 88% to 73%. CONCLUSIONS: CT obtained before stenting was the single most useful test, providing correct diagnosis in 88% and resectability in 71% of patients. If no tumor is depicted in CT, EUS should be added. Uncertain venous vessel infiltration can be verified by MRI or EUS. Angiography should no longer be a routine diagnostic procedure. Equivocal tumors or possible metastasis may be further examined with PET.

Ampulla of Vater↗
PubMed2001

Endovascular grafting of traumatic aortic aneurysms in contaminated fields.

PURPOSE: To evaluate the potential of endovascular stent-grafts to treat traumatic aortic lesions in contaminated areas. METHODS: Four patients (3 women; ages 26-78 years) underwent stent-grafting to repair an aortic rupture sustained in a motorcycle accident, aortic lacerations secondary to surgical treatment of spondylitis in 2 patients, and an aortobronchial fistula following surgical thoracic aortic repair 10 years earlier. Stent-grafts (2 Corvita, 1 Talent, and 1 Vanguard) were placed endoluminally into the infected areas via a transfemoral approach. Follow-up included erythrocyte sedimentation rate, white blood count, C-reactive protein, blood cultures, and computed tomography (CT). RESULTS: The stent-grafts were successfully placed in all cases and excluded the aortic lesion. Under supportive antibiotic therapy, inflammation parameters returned to normal. CT imaging showed no evidence of paraprosthetic infection, nor were there any other complications over a follow-up that ranged from 3 to 34 months. CONCLUSIONS: Endovascular therapy may be an alternative in the acute management of aortic ruptures in the setting of infection. Long-term results are required for definitive evaluation of the method.

Adult↗
PubMed2001

Thrombus formation in aortic endografts.

PURPOSE: To examine the incidence of intraprosthetic thrombotic deposits in aortic endografts. METHODS: Transfemoral implantation of tube or bifurcated stent-grafts was performed in 82 patients (75 men; average age 67.7 years, range 25-88) for treatment of aneurysms of the abdominal (n = 73) or thoracic (n = 9) aorta in a 3.5-year period. Patients underwent 3-phase helical computed tomographic (CT) examinations at 3-month intervals. The length and cross-sectional area of any thrombotic deposits were measured from axial and 3-dimensional CT images. RESULTS: Over a 12.1-month mean follow-up, intraluminal deposits of thrombotic material were observed in 19 (23.2%) patients, all with infrarenal endografts that were predominately of a bifurcated design. The first signs of thrombus formation occurred on average 7 months postoperatively (range 1 week to 20 months). In 16 patients, nonocclusive deposits of thrombotic material were seen in the aortic segment of the endograft; a graft limb was involved in 5 patients. Three graft limbs occluded owing to kinking; no thrombus was seen on CT scans taken prior to occlusion. In 3 cases the thrombotic deposits disappeared completely from the prosthesis lumen during follow-up. CONCLUSIONS: Based on this small experience, nearly 1 in 5 patients may experience some degree of intraluminal thrombus following endovascular treatment of aortic aneurysms. Whether the deposition of thrombus is influenced by the geometry of the aortic stent-graft or by flow conditions within the prosthetic lumen must be determined in future studies.

Adult↗
PubMed2001

Ability of MR cholangiography to reveal stent position and luminal diameter in patients with biliary endoprostheses: in vitro measurements and in vivo results in 30 patients.

OBJECTIVE: Our goal was to evaluate the ability of MR cholangiography to show stent position and luminal diameter in patients with biliary endoprostheses. MATERIALS AND METHODS: Susceptibility artifacts were evaluated in vitro in three different stent systems (cobalt alloy-based, nitinol-based, and polyethylene) using two breath-hold sequences (rapid acquisition with relaxation enhancement, half-Fourier acquisition single-shot turbo spin echo) on a 1.5-T MR imaging system. The size of the stent-related artifact was measured, and the relative stent lumen was calculated. In vivo stent position and patency were determined in 30 patients (10 cobalt alloy-based stents, five nitinol-based stents, and 15 polyethylene stents). RESULTS: In vitro, the susceptibility artifact of the cobalt stent caused complete obliteration of the stent lumen. The relative stent lumens of the nitinol-based and polyethylene stents were 38-50% and 67-100%, respectively. In vivo, all stents were patent at the time of imaging. The position of the cobalt alloy-based stent could be determined in nine of 10 patients, but stent patency could not be evaluated. Stent position of nitinol stents could not be adequately evaluated in any of the five patients, and internal stent diameter could be visualized in only one patient. In nine of 15 patients, the fluid column within the implanted polyethylene stent was seen on MR cholangiography. CONCLUSION: The internal stent lumen could be visualized in most patients with an indwelling polyethylene stent, but not in patients with cobalt alloy- or nitinol-based stents.

Adult↗
PubMed2001

Preoperative diagnosis of ovarian tumors with MR imaging: comparison with transvaginal sonography, positron emission tomography, and histologic findings.

OBJECTIVE: Our study evaluated the diagnostic performance of MR imaging compared with that of transvaginal sonography and positron emission tomography (PET) in patients with clinically asymptomatic adnexal findings. An additional goal was to determine whether the combination of the three methods enhanced their diagnostic accuracy. SUBJECTS AND METHODS: Included in the study were 103 women with suspicious adnexal findings on sonography. Patients underwent transvaginal sonography, MR imaging, and PET within 3 weeks of the initial sonography. For MR imaging, axial and sagittal T1-weighted gradient-echo sequences (unenhanced and enhanced) and T2-weighted turbo-spin-echo sequences were acquired. Transvaginal sonography was performed with a 7.5-MHz transducer head. For PET, a modern full-ring scanner was used. The results of diagnostic imaging techniques were first evaluated separately, and reviewers were blinded to the results of other methods. Finally, a second session resulted in a consensus diagnosis based on the findings of all three methods. Results of histology were considered the gold standard. RESULTS: Histology revealed 12 malignant and 91 benign ovarian tumors. The following data were calculated for MR imaging, transvaginal sonography, PET, and consensus diagnosis: sensitivities, 83%, 92%, 58%, 92%; specificities, 84%, 59%, 78%, 84%; diagnostic accuracies, 83%, 63%, 76%, 85%, respectively. MR imaging, particularly with contrast-enhanced fat-saturated T1-weighted sequences, was found to correctly reveal dermoid and endometrial cysts. All three methods had false-negative findings with borderline tumors. CONCLUSION: Transvaginal sonography is the diagnostic method of choice as a screening technique for ovarian processes. Suspicious findings on transvaginal sonography should be confirmed on MR imaging. If MR imaging confirms a dermoid or endometrial cyst, further diagnostic procedures may be unnecessary. In all other cases, a surgical evaluation must be considered.

Adolescent↗
PubMed2001

Metallic stents in benign biliary strictures: long-term effectiveness and interventional management of stent occlusion.

OBJECTIVE: The objective of our study was to evaluate the long-term effectiveness of metallic stent placement in the treatment of benign biliary strictures and to report our experience with interventional procedures for the management of stent occlusion to achieve secondary patency. CONCLUSION: The clinical course of these patients is compromised by repeated stent occlusions, caused by stone or mucosal hyperplasia. The results of primary stent patency are disappointing with the primary patency rate decreasing from 75% after 12 months to 25% after 36 months. The different interventional procedures used to restore bile flow make an important contribution to the secondary stent patency and provide a satisfactory clinical result in a patient subpopulation in whom stent placement is considered the last resort.

Adult↗
PubMed2000

Classification of asymptomatic adnexal masses by ultrasound, magnetic resonance imaging, and positron emission tomography.

OBJECTIVE: The purpose of this study was to determine the diagnostic accuracy of sonography versus magnetic resonance imaging (MRI) and positron emission tomography (PET) in the characterization of adnexal masses. METHODS: One hundred and one patients with asymptomatic adnexal masses, which were scheduled for laparoscopy, underwent preoperative transvaginal ultrasound, MRI, and 2-[(18)F]fluoro-2-deoxy-d-glucose PET. Two different sonomorphological scoring systems were used to distinguish malignant from benign lesions. In addition, transvaginal Doppler flow velocimetry was performed and the resistance index (RI) of ovarian blood vessels was calculated. RI values below 0.45 were considered to indicate malignancy. MRI was evaluated on the basis of signal intensity and morphologic features such as wall thickness, septations, fluid or solid components, and vascularity. PET imaging was used to determine 2-[(18)F]fluoro-2-deoxy-D-glucose uptake. Malignancy was suspected if radiotracer uptake equaled or exceeded that of the liver. Based on histologic findings, sensitivity, specificity, positive and negative predictive values, and accuracy were first calculated independently for each imaging technique. Finally, a second session resulted in a consensus diagnosis being made based on the findings of all three modalities. RESULTS: Sonographic evaluation of adnexal masses resulted in correct classification of 11 of 12 ovarian malignancies (sensitivity 92%) but with a specificity of only 60%. With MRI and PET, specificities improved to 84 and 80% respectively, but sensitivities decreased. When all imaging modalities were combined, sensitivity and specificity were 92 and 85%, respectively, and accuracy was 86%. CONCLUSION: Combination of ultrasound with MRI and PET may improve accuracy in differentiation of benign from malignant ovarian lesions. However, negative MRI or PET results do not rule out early-stage ovarian cancer or borderline malignancies.

Adnexal Diseases↗
PubMed2000

[Benign bile duct stenoses. Treatment with flexible metal wire stent or silicone prostheses (Yamakava) in nonresectable stenoses or high surgical risk cases].

INTRODUCTION: High benign biliary stenoses, which can occur as a complication of disease or surgery, may be difficult to correct by open surgery and may also carry a high risk. An alternative to surgery is the percutaneous implantation of a flexible metallic stent or silicon prosthesis at the affected site. METHODS: Twelve patients with benign biliary stenoses have been operated on in our department since March 1992, and the therapeutic success was reviewed in this study. RESULTS: Six received a Palmaz stent and six a silicon prosthesis, with a follow-up after completion of treatment of more than 7 years and more than 3 years, respectively. Fifty percent of the patients with a stent experienced no problems and 66% of the stents remained patent (including one requiring operative intervention to restore patency). No further surgery was necessary in any of the patients with a silicon prosthesis. CONCLUSION: When the advantages and disadvantages of the various procedures are considered, long-term splinting with a wide-lumened silicon prosthesis (Yamakava) appears to be a promising alternative to surgery for the treatment of benign biliary stenosis.

Adult↗
PubMed2000

[Ischemia of the lower extremity due to a persistent a. ischiadica--a possible interventional therapeutic approach].

The sciatic artery is a rarely seen variant of the vessels of the lower limb. Anatomically it is the prolongation of the inferior gluteal artery and accompanies the sciatic nerve from the sciatic foramen to the knee. More than other vessels, the sciatic artery shows vasculopathies like diffuse dilatation or aneurysms. This report describes an interesting case of embolic acute ischemia, caused by a persistent sciatic artery with an aneurysm. We treated the ischemia with intra-a. lysis and bridged the aneurysm with an covered stent.

Acute Disease↗
PubMed2000

Primary staging of lymphomas: cost-effectiveness of FDG-PET versus computed tomography.

The objective of this study was to measure the incremental cost-effectiveness of 2-(fluorine-18) fluorodeoxyglucose positron emission tomography (FDG-PET) versus computed tomography (CT) as diagnostic procedures in the primary staging of malignant lymphomas. The study was based on 22 patients of a clinical study who underwent the diagnostic procedures at Ulm University Hospital between April 1997 and May 1998. Direct costs of FDG-PET and CT, including staff, materials, investment, maintenance and overheads, were valued using a micro-costing approach. The effectiveness of both diagnostic procedures was measured as the percentage of correctly staged patients, given a gold standard for staging. The incremental cost-effectiveness ratio was the main outcome measure. Costs per patient of FDG-PET were 257 euros for FDG production and 704 euros for the FGD-PET scan, thus totalling 961 euros (in 1999 prices). The cost per patient of CT scans was found to be 391 euros. Verified PET findings induced an upstaging in four patients such that the effectiveness was 81.8% (18/22) for CT and 100% (22/22) for PET. Incremental cost-effectiveness ratios (interpreted as the additional costs of a more effective diagnostic strategy per additional unit of effectiveness, i.e. additionally correctly staged patient, achieved) were 478 euros per correctly staged patient for CT versus "no diagnostics" and 3133 euros for FDG-PET versus CT. Great potential for cost saving was identified in sensitivity analyses for FDG-PET. It is concluded that diagnostic accuracy and the costs of the diagnostic procedures could be measured precisely. FDG-PET was more accurate than CT. Decision-makers who consider savings in treatment costs significant may find the cost-effectiveness ratio of PET to lie within an acceptable range. However, more research is needed to assess the long-term treatment and cost effects of more accurate staging. There is significant potential to improve the technical efficiency of PET.

Adolescent↗
PubMed2000

MRI in the diagnosis of small bowel disease: use of positive and negative oral contrast media in combination with enteroclysis.

The aim of the study was to evaluate the additional findings of MRI following small bowel enteroclysis and to compare the efficacy of negative and positive intraluminal contrast agents. Fifty patients with inflammatory or tumorous small bowel disease were investigated by small bowel enteroclysis and consecutive MRI using breathhold protocol (T1-weighted fast low-angle shot, T2-weighted turbo spin echo). Patients were randomly assigned to either receiving a positive oral (Magnevist, Schering, Berlin, Germany) or a negative oral MR contrast media (Abdoscan, Nycomed, Oslo, Norway). The pattern of contrast distribution, the contrast effect, presence of artifacts, as well as bowel wall and extraluminal changes, were determined and compared between the contrast type using Fischer's exact test. Sensitivity, specificity, and diagnostic accuracy for MRI and enteroclysis were calculated. Twenty-seven patients had clinically proven Crohn's disease and two patients surgically proven small bowel tumours. Magnetic resonance imaging had important additional findings as abscesses and fistulae in 20 patients. Surgically compared sensitivities were 100 and 0% for MRI and enteroclysis, for the detection of abscesses, and 83.3 and 17 % for the diagnosis of fistulae, respectively. Bowel wall thickening was more reliably detected with use of positive oral contrast media without intravenous enhancement (p < 0.001), whereas postcontrast negative oral contrast media allow for a superior detection (p < 0.001). T2-weighted sequences were necessary with use of negative oral contrast media, because loop abscesses may be masked. Magnetic resonance imaging should be performed in all patients with suspicion of extraintestinal complications, because the complications are more reliably detected by MRI. Negative oral contrast media show advantages with the use of intravenous contrast but can mask loop abscesses using only T1-weighted imaging.

Abscess↗