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Biomedical subjects

D Korbuly

Publications and source records attributed to D Korbuly.

11 recordsLinked to original sources
PubMed1982

Sources of artifacts in rotational scanography.

The images produced in rotational scanography, currently under investigation at several institutions, may contain several kinds of artifacts. The sources of such artifacts are: 1. vertical and horizontal misalignment of the focal spot with the axis of rotation; 2 misalignment of the primary and secondary slits; 3 a density gradient due to slit cut-off; 4 vibration of the x-ray tube during rotation; 5. A density gradient due to variation in motor speed; 6. radiographic striations due to ripple of the tube output. Striations are present even if a 12-pulse generator is used, but they disappear if a constant potential generator is employed.

Humans↗
PubMed1981

Radiographic scanning in barium examinations of the gastrointestinal tract.

The possibility of using radiographic scanning for gastrointestinal studies was evaluated experimentally. Two tubular barium-filled phantoms containing simulated ulcers and polyps were placed in a 25-cm water container, and radiographs made with the conventional technique and scanographic technique were compared. Images obtained with the radiographic scanner were superior in contrast and sharpness. Two-millimeter polyps could be easily detected in the larger phantom. Due to improved latitude the larger phantom could be adequately penetrated without overexposing the smaller phantom. This was not possible with the standard technique. Best results were obtained with a heavily filtered 140-kVp beam. Radiographic scanning has great promise in barium examinations of the gastrointestinal tract.

Barium Sulfate↗
PubMed1980

Scanography with rotation of the radiographic tube: a new method.

The quality of the radiographic image is compromised by secondary radiations and geometric unsharpness, which is proportional to the focal spot size. The authors describe a new system which significantly improves both elimination of scatter and reduction of the apparent focal spot size and gives superior radiographs to those made with a conventional x-ray machine. Advantages of the new system include (a) the lack of resolution and density gradients across the radiograph, (b) increased contrast due to descreased scatter, (c) increased resolution, (d) possible routine radiography with a 100-mu focal spot, (e) up to 2.5 x magnification, (f) increased acceptable kVp range, and (g) decreased dose to the patient.

Humans↗
PubMed1980

Changerless peripheral angiography: a new concept.

The authors describe a new technique using the principle of rotational scanography, in which the x-ray tube is rotated through the center of the focal spot and scans the field of interest. A single primary and secondary slot system in conjunction with an 8:1 grid is used for efficient scatter removal. If the speed of blood flow is increased by reactive hyperemia and a large amount of contrast medium is injected, the abdomen to the toes can be scanned with one injection. The advantages of this technique are that a 127-cm field can be covered with a 6 degree or 12 degree target tube and without an especially high ceiling, and the film changer is eliminated. The angiograms are markedly improved because virtually all scatter is eliminated, and exposure is reduced since only one radiograph is necessary.

Angiography↗
PubMed1980

Routine magnification lymphangiography with a swinging slot X-ray machine.

Bilateral pedal lymphangiography was performed in 85 patients. Anteroposterior, lateral, and oblique views of the pelvis and abdomen were obtained with conventional radiographic technique and compared with 1.8 X magnification views obtained with a radiographic scanner that had a multiple slot system and with magnification views obtained with a standard 0.3-mm focal spot and a 12:1 grid.

Humans↗
PubMed1978

The "swinging" tube: a new concept.

A new technique converts a standard biased x-ray tube into a microfocal spot tube with a clinically useful loading capacity. If the tube is pivoted exactly through the focal spot, the film can be scanned with a 5-10 cm wide beam and cover a 17-inch field. Then the target angle can be decreased to a few degrees. The width of the focal spot can be decreased using a grid bias.

Radiography↗
PubMed1977

A new simple power injector.

A new simple pneumatic-hydraulic injection device has been constructed, tested, and used in clinical angiography. Is is the only injector which produces a square wave velocity curve with immediate rise time. Disposable plastic syringes are used which convert the velocity profile of the plunger into a smooth buildup time of the injectate, reducing recoil. The unit can be operated by both local or remote triggering. It has numerous advantages over commercially available devices, such as small size, simplicity of design, and safety features which eliminate shock hazards and reduce human error.

Angiography↗
PubMed1976

A method to absorb scattered radiation without attenuation of the primary beam.

A method is presented for improving image quality by decreasing the scattered radiation. Two pairs of lead plates, one above and one below the patient, move in arcs with a common pivot point, the focal spot of the x-ray tube. The lower plates are separated by a 1-cm slot. The upper plates are also separated by a slot, the edges of which lie on common radii from the focal spot. The image is formed by moving the slots so that the X-ray beam emerging from the object sweeps across the film with a uniform speed during the exposure.

Humans↗
PubMed1976

The effect of valium on myocardial blood flow.

The effect of Valium on coronary blood flow was studied. In 18 patients undergoing coronary angiography, total and regional myocardial blood flow was determined by the 133Xe wash-out technique. A total of 39 pre- and 39 post-Valium injection wash-out curves were constructed. Results indicate (99% confidence) that intravenous Valium injection (0.1 mg/kg body weight) decreases myocardial blood flow 12--15%.

Angiography↗
PubMed1975

Regional Myocardial Blood Flow Measurement in the Evaluation of Patients with Coronary Artery Disease.

Myocardial imaging with 133-Xe and a gamma camera was employed to evaluate total and regional myocardial blood flow. The technique detected vasodilatation after injection of papaverine or diatrizoate. Contrast medium caused transient vasodilatation with return to baseline flow within five minutes. Myocardial tissue flow tended to decrease as coronary artery stenosis became more severe. There was overlap of flow measurements in patients with and without coronary artery disease. Coronary flow measurements made at rest are not considered to be an essential clinical tool. gpreater diagnostic benefit is obtained from the scintigram which distinguishes between akinesia caused by ischemia and akinesia due to extensive scarring.

Contrast Media↗