Biomedical subjects

L J Kool

Publications and source records attributed to L J Kool.

4 recordsLinked to original sources

PubMed1992

AMBER and conventional chest radiography: comparison of radiation dose and image quality.

The authors compared the radiation dose to the patient and the image quality in advanced multiple-beam equalization radiography (AMBER) with those in conventional chest radiography. Organ doses were estimated for an anthropomorphic phantom from measurements with thermoluminescence dosimeters. These measurements were supplemented with area-air kerma products obtained during chest examinations of 223 patients. Image quality was determined by means of a contrast-detail image evaluation test. An improvement in image quality in regions of high absorption and an increased dose to the patient were found for the AMBER technique compared with the conventional technique. However, for both techniques, the radiation exposure was relatively low compared with other reported values of patient dose during chest radiography. The estimated effective dose for an average-size patient during chest radiography with posteroanterior and lateral projections is 0.085 mSv for the conventional and 0.14 mSv for the AMBER technique.

Humans↗

PubMed1988

AMBER: a scanning multiple-beam equalization system for chest radiography.

Conventional chest radiography is limited by the small useful exposure range of radiographic film. The wide variation in absorption thickness of different parts of the chest results in areas of under- and over-exposure. An advanced multiple-beam equalization system, AMBER, controls local exposure delivered to the film. The system has a row of 20 modulators in front of the x-ray tube, each able to change the height of the local slit beam during scanning. Changes are made in response to measurements from a linear detector array in front of the film cassette. This array consists of 20 individually functioning detectors coupled through electronic feedback loops to the 20 modulators. A scan is obtained in 0.8 second with a local exposure time of approximately 50 msec. AMBER results in radiographs with significantly improved exposure of the mediastinum without overexposure of the lungs.

Humans↗

PubMed1988

Advanced multiple-beam equalization radiography in chest radiology: a simulated nodule detection study.

To evaluate the efficacy of AMBER, a multiple-beam equalization system for chest radiography, the authors performed a nodule detection study using an anthropomorphic chest phantom. AMBER and conventional images were compared. The images were read by four observers, and analysis was done by means of modified receiver-operating characteristic (ROC) curves (free ROC curves [FROC]). The results of the FROC analysis show a significant increase in the detectability of nodules (P less than .001) projected over the mediastinum with the use of AMBER. No significant difference between AMBER and conventional images was noted in detectability of nodules projected over the lung.

Humans↗

PubMed1987

Pulmonary leukostasis: radiologic-pathologic study.

The terminal chest radiographs of ten patients with pulmonary leukostasis were correlated with the autopsy findings. In six patients, no abnormalities attributable to leukostasis were seen on chest radiographs. In four patients, diffuse alveolar consolidations were caused by alveolar edema following leukostasis. Leukostasis should be considered in leukemia patients with severe dyspnea who have normal chest radiographs or diffuse alveolar edema.

Cause of Death↗