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Biomedical subjects

D Banzer

Publications and source records attributed to D Banzer.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Development of a CT data-based score for prediction of fracture risk in osteoporosis].

It should be examined how far BMD semiquantitative (profile analysis) and qualitative datas (architecture of spongy bone, age of patient) can be combined in one score in order to improve the assessment of fracture risk. SE-QCT was performed in 220 patients with a mean age of 55.8 (33-84) years from whom conventional X-ray images of the thoracic and lumbar spine were available. In the axial scans spongiosa architecture was classified and a density profile analysis was carried out. This was followed by gradation of BMD values, different types of spongiosa architecture, profile analysis and age of patient to a numerical score. This was compared to the number of fractures, whereby the patients were separated into three groups: group I = no fracture, group II = one fracture, group III = more than one fracture. The BMD values, types of spongiosa architecture, semiquantitative profile analysis can be significantly assigned to the groups I and II (p < 0.02), groups I and III (p < 0.001), and the groups II and III (p < 0.05). By combining BMD values, architecture of spongy bone, density profile analysis, and age of patients without fracture, scale 8-12 = patients with or without fracture, scale 13-16 = patients with at least one fracture [corrected].

Adult↗
PubMed1996

MR diagnosis of retropatellar chondral lesions under compression. A comparison with histological findings.

PURPOSE: The aim of the study was to improve the chondromalacia patellae (CMP) diagnosis by MR imaging under defined compression of the retropatellar cartilage, using a specially designed knee compressor. The results were compared with histological findings to obtain an MR classification of CMP. METHOD: MR imaging was performed in in vitro studies of 25 knees from cadavers to investigate the effects of compression on the retropatellar articular cartilage. The results were verified by subsequent histological evaluation. RESULTS: There was a significant difference in cartilage thickness reduction and signal intensity behaviour under compression according to the stage of CMP. CONCLUSION: Based on the decrease in cartilage thickness, signal intensity behaviour under compression, and cartilage morphology, the studies permitted an MR classification of CMP into stages I-IV in line with the histological findings. Healthy cartilage was clearly distinguished, a finding which may optimize CMP diagnosis.

Adolescent↗
PubMed1996

Ultrasound and soft-tissue radiography to monitor local interferon-alpha 2B treatment in Peyronie's disease.

PURPOSE: We attempted to assess objectively the response of Peyronie's disease plaques to local interferon-alpha 2B. MATERIAL AND METHODS: Twenty patients were treated with 5 local injections of 1 million units of IFN-alpha 2B into a single designated plaque. Before treatment, and 4 weeks and 6 months after treatment, the plaques were examined ultrasonographically. Each time, a histogram profile was performed. All patients also underwent soft-tissue radiography in 2 planes using the mammography technique before and 6 months after treatment. RESULTS: We found that with ultrasonography the plaques could be classified into 3 groups depending on degree of calcification, from nil to complete. Radiography detected calcifications better than ultrasonography but failed to detect plaques without calcification. The degree of calcification was negatively correlated with the response to treatment, since noncalcified plaques responded best, while fully calcified plaques failed to respond. CONCLUSION: In Peyronie's disease, ultrasonography is an important tool for non-invasive monitoring treatment response and for preselecting patients for medical treatment.

Follow-Up Studies↗
PubMed1995

Evaluation of penile arteries with color-coded duplex sonography: prevalence and possible therapeutic implications of connections between dorsal and cavernous arteries in impotent men.

Penile revascularization for cases of arteriogenic impotence is based on the assumption of hemodynamically relevant connections between the dorsal penile and cavernous arteries. In 325 clinically impotent patients color-coded duplex sonography was performed with the penis flaccid and tumescent after intracavernous injection of 10 micrograms prostaglandin E1. We measured peak flow velocity, end diastolic flow velocity and resistance in the dorsal arteries, deep cavernous arteries and connections perforating the tunica albuginea between the 2 systems. Of our patients 14% had at least 1 such anastomosis with a peak flow velocity exceeding 25 cm. per second after stimulation. Peak flow velocities less than 20 cm. per second were noted only in arteriogenically impotent patients, while those exceeding 25 cm. per second without later rigid erection occurred only in patients with venous occlusive dysfunction and end diastolic flow velocity exceeded 5 cm. per second. We conclude that penile revascularization should be contemplated only if hemodynamically relevant connections are detected, peak flow velocity in the cavernous arteries is less than 20 cm. per second and end diastolic flow velocity is less than 5 cm. per second.

Alprostadil↗
PubMed1995

[The value of in-vivo 31-phosphorus spectroscopy in the diagnosis of generalized muscular diseases. The clinical results and the differential diagnostic aspects].

PURPOSE: In a prospective study, characteristics and the diagnostic potential of in vivo 31-phosphorus spectroscopy in cases of generalised muscle diseases were analysed. METHOD: 41 patients with myogenic and neurogenic muscle diseases and 11 healthy volunteers were examined using MRI and in vivo 31-phosphorus spectroscopy by means of a 50 mm double-tuned surface coil. RESULTS: The spectra showed significant changes of the metabolite ratios depending on the degree of the disease. Inflammatory muscle diseases were characterised by increased PME and PDE peaks, which indicates that there is a higher conversion of the cell membrane. The spectra of muscular dystrophy showed a slight increase of PDE and Pi. A strongly reduced PCr and an increased Pi peak were demonstrated in cases of muscle atrophy depending on their degree of markedness. The pH values were minimally increased in comparison to the volunteers. In other muscle diseases, such as glycogenosis or myotonia, no significant changes were detected. CONCLUSION: Standardised in vivo 31-phosphorus spectroscopy of generalised muscle diseases provides noninvasive prognostic information on the type and behaviour of the disease and is complementary to clinical and histological findings.

Adolescent↗
PubMed1995

[Diagnosis of cerebral metastasis with standard dose gadobutrol vs. a high dose protocol. Intraindividual evaluation of a phase II high dose study].

PURPOSE: To assess the effectiveness and safety of normal and high doses of Gadobutrol versus a standard dose of Gadolinium DTPA in the MR evaluation of patients with brain metastases. MATERIAL AND METHODS: In a clinical phase-II study 20 patients who had been diagnosed as having brain metastases with CT or MRT were studied prospectively with Gadobutrol, a new nonionic, low osmolality contrast agent. Each patient received an initial injection of 0.1 mmol/kg body weight and an additional dose of 0.2 mmol/kg Gadobutrol 10 min later. Spin-echo images were obtained before and after the two applications of Gadobutrol. Dynamic scanning (Turbo-FLASH) was performed for 3 min after each injection of the contrast agent. Both quantitative and qualitative data were intraindividually evaluated. The primary tumor was a bronchial carcinoma in 11 cases; in 9 other cases there were different primary tumors. RESULTS: Forty-eight hours after the use of Gadobutrol there were no adverse signs in the clinical examination, vital signs or blood and urine chemistry. Statistical analysis (Friedman test and Wilcoxon test) of the C/N ratios between tumor and white matter, percentage enhancement, and visual assessment rating revealed statistically significant superiority of high-dose Gadobutrol injection in comparison to the standard dose. The percentage enhancement increased on average from 104% after 0.1 mmol/kg to 162% after 0.3 mmol/kg Gadobutrol. Qualitative delineation and contrast of the lesions increased significantly. The use of high-dose Gadobutrol improved the detection of 36 additional lesions in 6 patients. CONCLUSION: The first in vivo results prove the excellent contrast capacity of the nonionic contrast agent Gadobutrol for the diagnosis of intracerebral metastases.

Adult↗
PubMed1995

[Multiple slab MR angiography of the A. carotis interna: a preoperative comparative study].

PURPOSE: With the introduction of MR angiography (MRA) into clinical routine, arteriosclerotic lesions of the supraaortic vessels may be well demonstrated. MATERIAL AND METHODS: The comparison between Multislab MRA (gradient echo, TOF) and X-ray angiography (XRA) as reference in 70 patients suspicious of stenotic lesions in the internal carotid artery proved the high reliability of these methods. RESULTS: In determining the degree of stenosis, according to the NASCET study (North American Symptomatic Endarterectomy Trial), a correlation between MRA and XRA of 92.3% could be calculated. The principal problem of MRA is the overestimation of high-grade stenoses; we observed 5 false-positive results in severe stenosis. Sensitivity and specificity were 95.6 and 92.6%, respectively, for detection of severe (> 60%) stenosis. CONCLUSION: Despite its limitations, MRA is a clinically important noninvasive technique for preoperative evaluation of patients undergoing carotid endarterectomy.

Adult↗
PubMed1994

[The quantitative determination of bone mineral content--a system comparison of similarly built computed tomographs].

An intercomparison of 4 CT scanners of the same manufacturer was performed. The bone mineral content of 11 lumbar vertebral columns removed directly post mortem was determined in a specially constructed lucite-water phantom. Even devices of the same construction were shown to yield a variation in the quantitative evaluation markedly exceeding the annual physiological mineral loss. As long as scanner adjustment by physical calibration phantoms has not yet been established, a course assessment and therapy control of bone mineral content should always be carried out on the same QCT scanner.

Absorptiometry, Photon↗
PubMed1989

[Computerized tomography determination of bone mineral content in quantitative diagnosis of osteoporosis].

Quantitative determination of bone mineral content has become important for the early diagnosis of osteoporosis prior to radiological evidence of vertebral deformities. Quantitative CT (QCT, computer tomometry), whether the single-energy (SE-QCT) or the dual-energy (DE-QCT) technique is used, yields volume-related values that can be used for accurate and reproducible assessment of spongious and cortical vertebral bone mineral. QCT seems to be superior to photon absorptiometry for early detection and follow-up of osteoporosis.

Adult↗
PubMed1988

[Quantitative computerized tomographic determination of bone mineral content].

Quantitative computed tomography (QCT) for measuring bone mineral content of lumbar vertebrae is increasingly used internationally. The effect of using conventional CT (single energy CT, SE-CT) and dual energy CT (DE-CT) on reproducibility has been examined. We defined a standard measurement protocol, which automatically evaluates a calibration phantom. This should ensure an in vivo reproducibility of 1 to 2%. Reference data, which has been obtained with this protocol from 113 normal subjects, using SE-CT and DE-CT, are presented.

Adult↗
PubMed1986

Diagnostics of extra-cranial carotid stenoses. Comparison of CW-Doppler sonography and intravenous digital subtraction angiography.

In 98 internal carotid arteries, continuous-wave ultrasound Doppler sonography (USD) and i.v. digital subtraction angiography (DSA) of the internal carotid arteries were performed. The findings were compared with each other prospectively and on the basis of conventional angiography findings. The aim of this investigation was to clarify, whether DSA would show stenoses with lumen restriction of less than 50% more precisely than USD, or whether it would enable clearer localization of any vascular lesions. The results revealed that in cases of haemodynamic effective stenoses and occlusions both procedures correlated well with each other and also with catheter angiography. However, USD and DSA showed increasing discrepancies of findings with decreasing degree of severity of the stenosis. The accuracy for localization of stenoses also decreased markedly for both methods with increasing distance from the carotid bifurcation. In the case of congruent findings of USD and DSA in haemodynamic effective stenoses (degree of stenosis more than 75%) or occlusions conventional angiography did not increase the diagnostic information, and it seems therefore dispensable for vascular surgical decisions. However, in cases with existing clinical symptoms with contradictory or negative USD and DSA findings angiography is still indicated.

Adult↗
PubMed1985

[Modification of the image quality of i.v. DSA by the iodine concentration of the contrast medium].

In randomised, double-blind clinical trials it could be demonstrated that in iv. DSA the image quality is reduced if the iodine concentration of the nonionic contrast medium iopromide is higher than 370 mgI/ml, the total amount of injected iodine being constant. This effect is due to the increased viscosity of contrast media containing a high iodine concentration per ml solution. The increased viscosity produces a longer transit time of the contrast material from the injection site to the target region. Due to this effect there is an increased dilution of contrast material with blood.

Cerebral Angiography↗
PubMed1984

[Iopromide, a new contrast medium for angiography. Clinical study and comparison with other low-osmolar contrast media].

In a multi-centre randomized double-blind study the ionic dimer ioxaglate was compared with the nonionic monomer iopromide. In a second randomized double-blind study iopamidol was included in the trial. It was shown that with low-osmolar substances sensitivity to pain and warmth occurred to only a slight extent, whether the contrast medium was ionic or non-ionic. An advantage of the non-ionic preparation was the definitely lower incidence of skin-rash, dizziness, nausea and vomiting.

Angiography↗
PubMed1984

Bolus geometry and dynamics after intravenous contrast medium injection.

Studies of contrast medium bolus geometry and dynamics were carried out to provide data for optimizing the use of contrast medium in digital subtraction angiography (DSA) and dynamic CT. Apparatus for fast digital recording of x-ray attenuation profiles was used; this is a new digital imaging mode (Chronogram) available on a CT scanner. Variables studied were injection site, injection speed, contrast medium volume, and subsequent saline injection; peak time, full width at half maximum, and maximum contrast enhancement were recorded. Positioning of the catheter in the vena cava reduced peak time and increased enhancement. High injection speeds led to shorter peak times. An increase in speed from 4 to 8 ml/s caused markedly higher enhancement, while further increase did not add significantly to enhancement. For a given injection speed, enhancement was increased and the peak time delayed by using larger injection volumes. Injection of saline solution after intravenous contrast medium did not change results significantly. There was a statistically significant correlation between pulse rate and peak time; the faster the pulse rate the shorter the peak time.

Angiography↗
PubMed1984

[Transvenous digital subtraction angiography for the diagnosis of renal artery stenosis in arterial hypertension. A comparison with conventional angiography].

Venous digital subtraction angiography was performed in 248 patients for the diagnosis of renal arterial stenosis. In 88% of the investigations the digital subtraction angiograms were of diagnostic value. Comparison of digital angiography and conventional angiography was made for 57 renal arteries (25 investigations). In 52 renal arteries we found the same results with both methods, in 5 renal arteries the digital angiography showed false positive results. The spatial resolution of digital subtraction angiography is sufficient for the correct diagnosis of significant renal arterial stenosis. With regard to the lower invasion of digital subtraction angiography compared to conventional angiography the first method should be used for clarification of renal arterial hypertension.

Angiography↗
PubMed1984

[Arterial digital subtraction angiography for visualizing hemodialysis shunts].

Intraarterial application of contrast medium in digital video subtraction angiography was used to visualize chronic haemodialysis arteriovenous shunts. Patient compliance could be enhanced by the use of small volumes of non ionic contrast medium (3 ml/inj.), and the use off thin needles. The diagnostic reliability was excellent for all 25 examinations.

Adult↗