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Biomedical subjects

H P Busch

Publications and source records attributed to H P Busch.

At least 55 records · Page 3Linked to original sources
PubMed1991

[The Kodak AMBER imaging system--a new approach to lung imaging].

The exposure range of X-ray films is often too small for objects with large absorption differences. This holds true also for wide latitude films. The large absorption differences can be equalized with the Kodak AMBER Imaging System by means of local exposure control. The AMBER System is a variation of the slit technique, where the narrowly collimated beam is divided into 21 beam segments the intensity of which is controlled in relation to the absorption in the object. This results in radiographs which are well exposed in the lung parenchyma and the mediastinum. An AMBER System has been routinely used for chest radiography in the Klinikum Mannheim since April 1990. The radiographs with the AMBER-Systems show an improved image quality especially in the mediastinum and the thorax wall resulting in a gain in diagnostic information.

Humans↗
PubMed1990

[Lung imaging in intensive medicine. A comparison of digital storage-screen imaging and conventional film-screen imaging].

Luminescence radiography is a new digital imaging modality, which can be used instead of conventional film radiography for many examinations. Imaging capabilities of luminescence radiography were compared with film radiography by test images and examinations especially in intensive care radiology. The results demonstrate, that luminescence radiography is an advantageous imaging method for intensive care radiology.

Humans↗
PubMed1989

[Digital image intensifier radiography--one year's experience with a Polytron system].

Since January 1988, digital image intensifier radiography has been used in the Clinic in Mannheim for DSA examinations and also in place of conventional screen/film examinations. Measurements have shown that compared with 100 mm and film/screen formats, digital radiography has poorer spatial resolution, but improved contrast resolution. The most common use of digital radiography was for examinations of the gastrointestinal tract. Using the demonstration of the mucosal fine relief pattern as a criterion of image quality, digital image intensifier radiography was able to achieve this satisfactorily. Comparison with film/screen examinations showed no loss of diagnostic information. Advantages of image intensifier radiography are reduced radiation dose, the possibility of postprocessing and economy. On the basis of 399 examinations, digital image intensifier radiography is now firmly established as part of the daily routine of the Mannheim Clinic.

Evaluation Studies as Topic↗
PubMed1989

[Obstetric pelvimetry using digital image intensifier radiography].

Obstetric pelvimetry can be performed by digital image intensifier radiography using very low exposure doses. Comparative measurements show a reduction of the entrance dose to 5% of conventional respectively 15% of high speed film-screen radiography. Phantom measurements have shown an accuracy of +/- 5 mm. In 30 patients the transverse diameter of the pelvic entrance, of the interspinous and of the intertuberous level as well as the sagittal diameter of the pelvic entrance and outlet were measured. Pelvimetry is indicated for the early recognition of certain risks if anamnestic (previous Caesarean section), clinical (eg. external pelvimetry) or fetometric features indicate the evidence of disproportion. As a radiological method the image intensifier radiography appears particularly recommendable in respect of its low exposure dose and the possibility of interactive measurements with subsequent documentation of the diameters and values.

Female↗
PubMed1989

[Hysterosalpingography with digital image intensification radiography].

Digital image intensifier radiography (Siemens/Polytron) offers the chance to reduce patient exposure dose in hysterosalpingography (HSG) by 85% compared with conventional film/screen radiography and by 11% compared with the 100 mm technique. By appropriate choice of the parameters the signal-to-noise ratio was adapted to the detectability of the diagnostic information (variation of the dose). Thirty patients were examined with the 28 cm image intensifier and an image intensifier input dose of 50 microR. The diagnostic image quality was assessed being aware of the results of laparoscopy or surgery; in 29 cases the quality was classified very good without any limitations. Digital image intensifier radiography offers additional advantages over conventional x-ray units: the images are directly available on the monitor and offer the possibility of post-processing.

Adult↗
PubMed1988

[Documentation of digital image information--video or laser imager?].

The quality of hardcopies produced by a video- or laser imager was compared. Laser printing could be performed after analogue or digital data transmission, whereas the video imager allowed only analogue data transfer. Evaluation of CT-, MR-, DSA- and radiographic images showed no difference in diagnostic information between video and laser-produced hardcopies. For large formats (35 X 35 cm.), laser images produced by digital transmission were considerably superior to video signals and analogue transmission. There were advantages and disadvantages of both types of imaging, depending on the size of the matrix, the type of image produced, ease of use and capital cost.

Copying Processes↗
PubMed1988

Parametric imaging of blood flow.

The calculation of functional images was based on recorded fluoroscopic sequences. The Fourier coefficients of the first harmonic were calculated for each matrix element, and the amplitude and phase values were used for the generation of two synthetic images. The amplitude image demonstrated the maximum change in opacification with high image contrast. Phantom studies showed that a high correlation exists between the inverse phase differences and flow. The clinical application of the Fourier method revealed substantial additional information to conventional angiography in one of ten patients. While the morphological evaluation demonstrated no significant stenosis, the functional images showed a residual stenosis.

Algorithms↗
PubMed1987

[Intra-arterial DSA versus conventional angiography in assessing the resectability of pancreatic and periampullary carcinomas].

Fifty patients were examined to determine whether intraarterial DSA can replace conventional angiography to assess the resectability of pancreatic and periampullary carcinomas. Intraarterial DSA yielded equivalent diagnostic information in 60% of the cases. As a result of contrast-enhanced visualisation of the splanchnic veins intraarterial DSA was superior to conventional angiography in 26% of the cases, whereas in 14% intraarterial DSA provided less information due to motion artifacts.

Adult↗
PubMed1987

Comparison of performance characteristics of different DSA-installations.

Standardized measurements of spatial resolution, contrast detectability, II entrance exposure and dynamic range were performed using simple and quick procedures for the assessment of performance characteristics. DSA-systems of different users and manufacturers can be compared with these performance criteria. Periodical measurements of performance are necessary to maintain a constant high image quality. The results of 10 DSA-systems demonstrate, that top of the line DSA-systems had a spatial resolution up to 1.2 lp/mm. and a contrast detectability up to 1 mm (10 mgI/ml) for an II-diameter of 22-26 cm.

Angiography↗
PubMed1986

[Intra-arterial DSA of the pelvic/leg vasculature using a 57 cm image intensifier].

100 consecutive intraarterial DSA's of the lower extremities obtained with a 57 cm image intensifier were evaluated retrospectively by 2 radiologists and 3 surgeons. The studies were considered diagnostic in 95% of the cases. The results, advantages and possible disadvantages are presented and compared to those associated with conventional film angiography and with i.v. DSA.

Angiography↗
PubMed1986

[Single-catheter technic for intra-arterial digital subtraction angiography of the aortic arch and selective imaging of the supra-aortic arteries].

A double-curve catheter with side-holes was used for intraarterial digital subtraction angiography of the aortic arch and selective angiography of the supraaortic arteries. Applying this technique the same catheter can be used in the majority of cases (approximately 75%) if aortic arch angiography is followed by selective catheterisation of the supraaortic arteries.

Angiography↗
PubMed1986

Computer processed fluoroscopic images for digital intravenous renal angiography.

We investigated intravenous digital angiography using computer processed fluoroscopic images. Computer processed fluoroscopy (CPF) was compared to conventional digital subtraction angiography (DSA) in 39 patients referred for renal vessel evaluation. For assessment of CPF the anterior-posterior images were compared with the corresponding digital subtraction angiograms. 79% percent of DSA and 71% of CPF studies were diagnostic. Peripheral injection of contrast medium caused deterioration of CPF images. Skin dose measurements were obtained in 24 patients. The median dose for DSA was 8.2 rad, compared to 1.1 rad for CPF. It is concluded that sophisticated algorithms should be investigated for digital angiography, so that high image quality can be achieved with a reduced radiation exposure.

Adult↗
PubMed1986

[Digital image intensifier radiography: imaging qualities and initial use in the gastrointestinal area].

We determined the quality of digital radiographs delivered by a large image intensifier (diameter 54 cm) and by a conventional fluoroscopic unit with a 33 cm image intensifier, and compared them to that of 100 mm spot films obtained from the same units. A special image processor was available allowing 25 images/s using a 512/512 matrix or 7.5 images/s with a 1024 X 1024 matrix. The spatial resolution of digital radiographs was well below that of the spot films, while no difference was found in contrast resolution. Images of colon specimens and gastrointestinal studies demonstrate that digital radiography does not imply a loss in diagnostic information inspite of the lower spatial resolution. Gastrointestinal studies using digital radiographs will reduce the amount of irradiation exposure of the patient and could represent an additional use for an existing equipment for DSA.

Colon↗
PubMed1985

[1 year's experience with a 57-cm image intensifier in a universal roentgen work station].

3342 patients were examined by means of a 57 cm image intensifier during one year. The installation permits examination with the patient standing or lying. The resolution was measured with a lead grid under conditions resembling actual practice and were found to be similar to those obtained with angiographic equipment. Using a medium format technique for examining the gut and vascular system resulted in radiographic quality which was not significantly different from the use of a large format technique. For examination of the skeleton, radiographic quality, using the intensifier, was markedly poorer than that resulting from Bucky examinations. There was no diagnostic difference when carrying out lymphograms. The large intensifier window of 53 cm was particularly advantageous for DSA of the pelvic and lower limb vessels when compared with smaller intensifiers. Possible savings of film and contrast medium costs are discussed.

Adult↗