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Biomedical subjects

D Banzer

Publications and source records attributed to D Banzer.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Catheter ablation of the inferior epigastric artery. An conservative method for conditioning the pedicled TRAM flap].

The pedicled transverse rectus abdominis musculocutaneous (TRAM) flap is a recognized, reliable method of autogenous tissue breast reconstruction after mastectomy. However, the blood supply to the distal part of the flap is often precarious after ligation of the the main feeder, the inferior epigastric artery (AEI), at time of the operation. We describe our clinical experience with a new technique to augment the superior blood stream (superior epigastric artery, AES) by selective embolization of the inferior epigastric artery some weeks prior to plastic surgery. One hundred and eleven embolization procedures were performed until now. Technique of crossover and ipsilateral epigastric spiral embolization is described, requiring minimal time and material as an in- or outpatient procedure. The anatomical situation of the m. rectus abdominis blood supply is discussed as well as possible complications of the procedure.

Anastomosis, Surgical↗
PubMed2000

[Clinical results and color-coded duplex ultrasound findings 4 years after conditioned TRAM flap-plasty].

Presented is a new technique in preoperative conditioning of the pedicled TRAM-flap employing an interventional-radiologic procedure, selective embolization of the deep inferior epigastric artery (DIEA). During a four year period in 40 patients with a mean age of 48.4 (31-66) years breast reconstruction was performed by a superiorly pedicled TRAM-flap following preoperative conditioning. 30 of 40 patients were eligible for follow-up one to five years postoperatively. The mean interval between embolization and surgery amounted to 3.6 months. In 25 of 30 cases embolization of the DIEA was performed bilaterally, in 5 of 30 cases unilaterally. 14 of 30 patients underwent preoperative radiotherapy for breast cancer. Applying CCDS the peak flow values were determined in the superior epigastric arteries (TRAM/contralateral side). Pre-embolization values (54.9 cm/s/55.8 cm/s), post-embolization values (57.2 cm/s/57.9 cm/s) and late postoperative values (61.0 cm/s/61.6 cm/s) proved a statistically significant effect of selective embolization on peak flow without relevant difference between TRAM and contralateral side (p < 0.05). Postoperative flap complications consisted of partial necrosis in 2 of 30, fat necrosis in 1 of 30, impaired would healing in 5 of 30 and postoperative bleeding in 2 of 30 cases. Abdominal would healing complications occurred in 5 of 30 cases, abdominal wall weakness was found in 8 of 30 and hernia formation in 4 of 30 cases. Corrective surgery was performed at the breast (TRAM-flap) in 22 of 30 and at the abdomen (donor site) in 9 of 30 cases. Patient acceptance concerning selective embolization and TRAM-flap surgery was very high. 29 of 30 patients confirmed that they would again choose this type of breast reconstruction. The pedicled TRAM-flap following preoperative conditioning by selective embolization of the DIEA constitutes a safe and reliable method of breast reconstruction with autogenous tissue. It is superior to the pedicled TRAM-flap without delay and offers definite advantages compared to alternative techniques of enhanced flap vascularization.

Adult↗
PubMed1999

A new ultrasound-based method for the assessment of torsional differences following closed intramedullary nailing of femoral fractures.

OBJECTIVE: A torsional difference of more than 15 degrees is found in up to 30% of patients following closed intramedullary nailing of femoral fractures. The diagnosis is usually established postoperatively by computed tomography. A torsional deformity of more than 15 degrees should be corrected by early derotation. In order to enable an intraoperative control and possible correction to avoid a second operation for the patient, a new ultrasound-based method suitable for the intraoperative setting has been developed, using the anterior condylar line as a distal reference line. DESIGN AND PATIENTS: In a prospective study the torsional difference after closed intramedullary nailing of femoral fractures was measured postoperatively by ultrasound in 32 patients and compared with standard CT readings. RESULTS: Torsional differences measured by ultrasound and CT showed a high correlation (r = 0.8) and a median difference of less than +/-3 degrees. CONCLUSIONS: By the introduction of the anterior condylar line as a distal reference line femoral torsion can accurately be assessed by ultrasound in a position required for intraoperative control and possible correction.

Adolescent↗
PubMed1999

[Imaging diagnosis in suspected inflammatory rheumatoid axial skeleton diseases (sacroilitis)].

Involvement of the sacroiliac joints is a hallmark of the spondyloarthropathies, especially in ankylosing spondylitis. The conventional diagnostic imaging of sacroiliitis in early stages might cause problems, because sensitivity of conventional radiographic methods is known to be too low in early stages of the disease. Magnetic resonance imaging of the sacroiliac joints certainly enables one to detect acute as well as chronic inflammatory changes in all stages of the disease. The potential disadvantages of this method are the dependency on the examiner, the lack of standardization, and the relatively high costs. Therefore, the "Workgroup of Diagnostic Imaging in Rheumatology of the Regional Center of Rheumatology of Berlin" including experienced rheumatologists, skeletal radiologists, and orthopedists acquired an imaging graduation for detection of sacroiliitis in consideration of the clinical background, the technical details of the methods, questions of ionizing radiation exposure, and cost effectiveness.

Cost-Benefit Analysis↗
PubMed1999

Imaging of hamate bone fractures in conventional X-rays and high-resolution computed tomography. An in vitro study.

RATIONALE AND OBJECTIVES: To examine the ability to image fractures of the body and hook of the hamate bone in conventional X-rays and high-resolution computed tomography (HR-CT). MATERIALS AND METHODS: In an in vitro experiment using 18 cadaver hands, the hamate bone was fractured at different places. Before and after fracture, conventional X-rays were taken in different planes (anteroposterior, lateral, oblique, and carpal tunnel), and HR-CT was performed with 2-mm layer thickness in the axial, sagittal, and coronal plane. RESULTS: Taking into account all the conventional X-ray projections applied, the in vivo experiment revealed a sensitivity of 72.2%, a specificity of 88.8%, and an accuracy of 80.5%. For the HR-CT, the sensitivity was 100%, the specificity was 94.4%, and the accuracy was 97.2%. CONCLUSIONS: Fractures of the body and hook of the hamate cannot always be detected with certainty in the conventional X-ray image, even if different projectional planes are used. The HR-CT is the imaging procedure of choice for further clarification, and an axial or sagittal plane should be selected.

Adult↗
PubMed1999

Computerized analysis of gray-value profiles in spongy and cortical bone. Clinical experience.

RATIONALE AND OBJECTIVES: Osteoporosis is characterized by a loss of bone mineral density and deterioration of structure. The authors present a structural parameter for the quantitative assessment of osteoporotic changes in vertebral bone. METHODS: In 40 patients without or with known osteoporotic fractures, spongiosa and cortical bone mineral density was measured in lumbar vertebrae 1 to 3 by quantitative CT. Additional axial high-resolution CT slices were obtained for the structural analysis. In the spongiosa, the gray-value profile along a horizontal line in the CT slice was used, whereas in the cortical shell a profile was obtained from the cortical ridge. Both profiles were intersected with a horizontal line of variable position, and the maximum number of intersections was determined. RESULTS: The maximum number of intersections is significantly higher in cases with fractures (spongiosa 48.6, cortical shell 77.3) than in cases without fractures (spongiosa 42.1, cortical shell 62.4). It also correlates with bone mineral density and age. CONCLUSIONS: The presented method shows significantly different numeric results for patients with and without osteoporotic fractures. The analysis is easy to perform and provides additional information on the bone structure that may be used in combination with bone mineral density measurements.

Adult↗
PubMed1999

CT determination of bone mineral density and structural investigations on the axial skeleton for estimating the osteoporosis-related fracture risk by means of a risk score.

In addition to the pure measurement of bone mineral density (BMD) in osteodensitometry, the investigation of bone structure is becoming increasingly important for estimating fracture risk. In a clinical study, a risk score was proposed which separately assesses BMD and structural parameters for spongious and cortical bone and aggregates them into a single diagnostic parameter. In 120 lumbar vertebrae from 40 patients, BMD was determined separately for spongious and cortical bone by means of quantitative CT using a single energy procedure (SE-QCT/85 kV). In addition, structural parameters based on high resolution CT were calculated for the spongiosa and cortical bone. For all patients the number of osteoporosis-related fractures was determined on the entire skeletal system. According to WHO criteria, the patients were subdivided into four groups: 1, normal; 2, osteopenic; 3, osteoporotic without fractures; 4, severely osteoporotic. Weighting factors were determined by means of multivariate least-squares analysis and used to calculate a risk score of all parameters. The ability of the individual parameters and of the sum of discriminate between the individual groups was tested. If one considers the individual parameters (BMD and the fractal structural values for spongious and cortical bone), they allow a statistically significant separation of the four groups, although there is overlapping in the value ranges. In patients with fractures, there was a significant reduction in the cortical mineral density, accompanied by a deterioration in structural properties. The following individual values were obtained (minimum-mean-maximum): spongiosa BMD (mg ml-1), unfractured: 62-112-163, fractured: 9-48-77; cortical BMD (mg ml-1), unfractured: 190-287-405, fractured: 133-191-269; spongiosa structural parameter, unfractured: 0.35-0.73-1.01, fractured: 0.95-1.24-1.58; cortical structural parameter, unfractured: 18-31-65, fractured: 21-44-66. Above 77 mg ml-1 CaHA in the spongiosa and 270 mg ml-1 CaHA in cortical bone, no fractures were observed. By appropriately selecting the weighting factors, the score is free of overlapping between the groups with and without fractures (values: unfractured 1-9-15, fractured 16-21-29). With higher score values, the fracture risk is increasing.

Adult↗
PubMed1998

[The reliability of radiologic findings for differential diagnosis of vertebral osteoporosis].

BACKGROUND: Radiologically identified vertebral deformities, e.g. wedge-, fish-, or crush-vertebrae are not always a consequence of local osteoporosis. Other frequent pathomechanisms include Morbus Scheuermann, degenerative changes, overt trauma, and congenital dysplasia. This requires differential diagnosis of vertebral deformities. Radiological classification criteria have to satisfy various methodological requirements to ensure reliability of the results. METHODS: Inter-rater reliability of more than 30 radiological findings was assessed in 4 German centres of the European Vertebral Osteoporosis Study (EVOS). One hundred randomly selected EVOS cases from the West-Berlin population, each contributing 2 lateral X-rays from the thoracic and lumbar spine respectively, were independently evaluated by 7 observers. All observers were medical doctors, 4 of them heads or members of clinical radiological departments. Thus each observer read 200 radiographs. Radiological alterations in the form and structure of 13 vertebrale which were considered to be relevant for the differential diagnosis of osteoporosis were recorded in a standardized documentation form. Additionally global judgements (e. g. "osteoporotic spine" yes/no) were required. To quantify agreement Fleiss' kappa (kappa) for nominal data and multiple observers was used.

Aged↗
PubMed1998

[Bone density of spongiosa and cortical bone of the lumbar spine. Relations to sex, age and spinal deformities in a regional collective of the European Study of Vertebral Osteoporosis (EVOS)].

BACKGROUND AND METHOD: In an additional bone density measurement protocol to the European Vertebral Osteoporosis Study (EVOS) separate spongious and cortical density measurements (sQCT) were carried out at the first 3 lumbar vertebrae in 293 volunteers (92 men and 201 women) in 3 Berlin regional centers. RESULTS: The spongious mineral density decreases from proximal to distal (L1 to L3), the cortical density increases from proximal to distal, mainly in men. Men showed no significant decrease of cortical density and a lower decrease of spongious density with age compared to women. A comparison of bone mineral density with vertebral height indices of McCloskey/Kanis, Eastell/Melton and Felsenberg showed significant differences of spongious density between a group with normal vertebral height and a group with at least one pathologically degraded vertebra. Individuals with osteoporosis according to the WHO-definition showed a higher prevalence of vertebral deformities. No significant loss of cortical density was observed in these people.

Age Factors↗
PubMed1998

[The imaging of hamate fractures in the conventional X-ray and CT: experimental results and clinical experiences].

PURPOSE: Examination of the ability to image fractures of the body and hook of the hamate bone in conventional X-rays and HR-CT. MATERIAL AND METHODS: In an in vitro experiment on 18 cadaver hands, the hamate bone was fractured at different localisations. Before and after fracture, conventional x-rays were taken in different projectional planes: a.-p., lateral, oblique and carpal tunnel view, as well as an HR-CT with 2 mm layer thickness in the axial, sagittal and coronal plane. In addition, 15 clinically verified hamate bone fractures (two body and 13 hook of hamate fractures) were reviewed retrospectively to assess the value of the imaging procedures that led to diagnosis. RESULTS: Taking into account all conventional x-ray projections applied, the in vitro experiment yielded a sensitivity of 72.2%, a specificity of 88.8% and an accuracy of 80.5%. For CT, the sensitivity was 100%, the specificity 94.4% and the accuracy 97.2%. In retrospective clinical evaluation, 60% of the existing fractures were identified in the conventional x-ray images. The remaining fractures were detected by additional procedures like scintigraphy, conventional tomography and CT. CONCLUSION: For the diagnosis of fractures of the body and hook of the hamate HR-CT is the imaging procedure of choice, in which case an axial or sagittal plane should be chosen.

Adult↗
PubMed1998

Bone mineral density and spongiosa architecture in correlation to vertebral body insufficiency fractures.

OBJECTIVE: The clinical value of spinal quantitative CT (sQCT) and the structural patterns of the vertebral bone were studied. MATERIAL AND METHODS: sQCT was performed on 246 patients with a mean age of 57 years for whom conventional lateral radiographies of the thoracic and lumbar spine were available. All patients were suffering from back pain of unknown etiology. The bone mineral density (BMD) of the midvertebral section of 3 lumbar vertebral bodies was determined by means of single-energy-(SE)-weighted QCT (85 kV). Spongiosa architecture and density profile analyses were made in the axial images. This was contrasted to BMD values ascertained in SE QCT. The mean BMD was compared to the number of fractures and the patients were divided into three groups: group I--no fracture; group II--one fracture; and group III > 1 fracture. RESULTS: The mean BMD was: 134.3 (74.1-187.5) mg hydroxyapatite (HA)/ml in group I; 79.6 (58.6-114.3) mg HA/ml in group II; and 52.4 (13.1-79.1) mg HA/ml in group III. A significant deterioration in spongiosa structure was found with increasing demineralization: strongly rarefied patterns predominated in the fracture groups II and III. CONCLUSION: sQCT provides a good risk assessment of the occurrence of vertebral body insufficiency fractures.

Adult↗
PubMed1998

Imaging modalities in Peyronie's disease. An intrapersonal comparison of ultrasound sonography, X-ray in mammography technique, computerized tomography, and nuclear magnetic resonance in 20 patients.

OBJECTIVE: Peyronie's disease is an ill-understood condition afflicting men in their 40s with the reported age ranging from 18 to 68 years. It is characterized by a plaque in the tunica albuginea which leads to penile deformity making sexual intercourse difficult if not impossible and is often accompanied by severe pain upon erection in the early stage; erectile dysfunction is present in about 2% of cases. Diagnosis rests upon medical history, clinical examination with plaque palpation and autophotography in two planes. These diagnostic steps are not plaque-specific and therefore we wanted to assess which imaging modalities would allow for an objective determination of the plaque status. MATERIALS AND METHODS: We evaluated 20 patients with Peyronie's disease. All patients underwent clinical examination including autophotography and the subsequent use of the following imaging techniques: (1) ultrasound (US) using a 7.5-MHz transducer with a profile for semiquantitative density analysis; (2) X-ray in mammography technique in two planes; (3) computerized tomography (CT) with a density profile, and (4) magnetic resonance imaging (NMR). RESULTS: (1) Degree of deviation: Penile deviation ranged from 15 degrees to 63 degrees. It was best assessed using radiography in mammography technique reflecting the results obtained by autophotography. (2) Calcifications: Plaque calcifications were seen in 12 patients, 8 had no calcifications but thickening of the tunica albuginea only, 2 also had a fibrosis of the corpus cavernosum distant to the plaque. Calcifications were visualized using ultrasound sonography (12/12), radiographically (12/12), CT (12/12), NMR (9/12). Thickening of the tunica albuginea only was visualized using ultrasound sonography (7/8), radiographically (0/8), CT (2/8), NMR (6/8). (3) Morphological pattern in ultrasound: Three distinct patterns could be detected: (type 1) the plaque appeared as a thickening of the tunica albuginea without acoustic shadowing and only minimal density increase in the histogram profile; (type 2) moderately calcified plaque with typical ultrasound shadow but minimal density increase in the density profile; (type 3) severely calcified plaque with typical acoustic shadowing and density increase in the histogram profile. (4) Plaque inflammation: Only NMR with gadolinium DTPA showed periplaque inflammation. CONCLUSIONS: High-resolution ultrasound sonography is the best imaging modality in assessment of plaques. NMR is the modality of choice to monitor the inflamed plaque. X-ray in mammography technique and CT are not necessary in daily routine.

Calcinosis↗
PubMed1997

Lung torsion--a rare postoperative complication. A case report.

Lung or lobe torsion is a rare condition that must be included in the differential diagnosis when a partial or complete shadow is detected on the lung. We report a case of this rare complication after chest surgery. The bedside radiograph provided initial evidence of torsion. CT verified the diagnosis of lower lobe torsion. Prompt recognition and intervention is imperative in order to save the affected lung.

Aged↗
PubMed1997

Assessing the degree of osteoporosis in the axial skeleton using the dependence of the fractal dimension on the grey level threshold.

Combining the measurement of bone mineral density (BMD) and the classification of the trabecular structure in cancellous bone improves the estimation of the degree of osteoporosis. A fractal method for the automatic quantitative classification of the trabecular structure in midvertebral slices of lumbar vertebrae is introduced. This method is based on the computation of the fractal dimension (box counting method) for varying binarization thresholds. Radiographic images from 30 lumbar vertebrae and CT images from an additional 16 lumbar vertebrae were analysed by calculating the dimension D in dependency of the threshold value T. The function D(T) was normalized by the average image grey value, eliminating the bone mineral density from the computations. The results show that the images of the lumbar vertebrae have fractal properties, and the function D(T) has a typical behaviour that allows the discrimination of the degree of osteoporosis. With two parameters extracted from the function D(T) the correlation coefficients with BMD were both -79% for the radiographic images, and -93% and -91% for the CT data, respectively.

Bone Density↗
PubMed1997

Evaluation of the cortical structure in high resolution CT images of lumbar vertebrae by analysing low bone mineral density clusters and cortical profiles.

The structural classification of trabecular bone is of considerable clinical importance for the diagnosis of osteoporosis. Assessment of the cortical bone mineral density (BMD) and analysis of cortical structure is necessary because the cortex is also affected by osteoporosis. We describe a method for the automatic classification of the cortex from its structure on high resolution (HR) CT images. The method is based on the distribution of areas with low BMD in the cortex. Two different approaches are presented; one uses the grey scale profile of the cortical ridge, and the other one evaluates the distribution of connected regions (clusters) of low BMD. i.e. areas that lie below a certain threshold value. In HRCT images from 22 lumbar vertebrae, the number of intersections of the cortical intensity profile with a horizontal line was determined at various positions of this threshold line. At a certain position, there was a local maximum in the number of intersections which was 38% higher in the osteoporotic cases. The maximum shows a moderate correlation with the cortical BMD of rni = -0.72 (p < 0.0001). The number nc of connected regions (clusters) with pixel values below a certain threshold value was determined in relation to the threshold value T. The resulting function nc(T) shows a relative maximum slightly below the average grey scale value of the respective image. The curve depends on the degree of osteoporosis: the height of the maximum (i.e. the maximal number of clusters ncmax) allows distinction to be made between different degrees of osteoporosis, and ncmax shows a correlation with the cortical BMD of rnc = -0.84 (p < 0.0001).

Aged↗
PubMed1997

[Soft tissue emphysema as manifestation of perforating diverticulitis].

Pronounced soft-tissue emphysema expressing disseminated fecal abscess formation in perforated colonic diverticulitis is described. Cervical, mediastinal, and thoracic dissemination and involvement of the scrotal space and the thigh reveal the original retroperitoneal localization as well as the unusual but potential dissemination. The diagnostic methods are described.

Abdominal Abscess↗