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Biomedical subjects

N D Greyson

Publications and source records attributed to N D Greyson.

At least 55 records · Page 3Linked to original sources

Sophisticated radiology in otolaryngology. II. Diagnostic imaging: non-roentgenographic (non x-ray) modalities (ultrasound, nuclear medicine, thermography).

Newer forms of radiologic diagnostic imaging now include non-roentgenographic modalities such as ultrasound, nuclear medicin, and thermography, all of which can be applied to otolaryngology. It is the purpose of this presentation to demonstrate these modalities, and indicate their clinical application, yet in its earliest stages, to otolaryngology.

Adult↗

Serial bone-scan changes in recurrent bone infarction.

Recurrent bone infarcts in a black man produced a changing pattern of bone-scan abnormalities. Areas initially cold at the infarction site returned to normal over a period of months. Hyperconcentration was frequently noted during the healing phase. In the acute phase scanning was specific and more sensitive than radiography.

Adult↗

Non-invasive screening for surgical intracranial lesions.

The value and reliability of the combined results of skull radiographs, electroencephalography, echoencephalography, isotope angiography, and brain scanning in 147 patients suspected of having an intracranial space occupying lesions are analysed. The overall accuracy of the technique was 79%. No false negatives were found. The advantages of adopting the system proposed by the authors in everyday clinical work is discussed.

Arteriovenous Malformations↗

Detection of postoperative bronchopleural fistulas by radionuclide fog inhalation.

Postoperative bronchopleural fistulas may be demonstrated quickly and safely by inhalation of nebulized (99m)Tc-albumin, or other similar radiopharmaceuticals. Posterior scintiphotographs of the distribution of the inhaled radioactive material are obtained with the gammaray scintillation camera while the patient is in the upright and lateral decubitus positions. The observation of radioactive material in the pleural cavity indicates an abnormal communication.The radiation-absorbed doses for lung and total body are well within acceptable limits when a (99m)Tc tag is used. About 15 minutes are required to complete this relatively safe diagnostic test.

Aerosols↗

Clinical comparison of 180-degree and 360-degree data collection of technetium 99m sestamibi SPECT for detection of coronary artery disease.

BACKGROUND: With multihead gamma cameras both 180- and 360-degree acquisitions of myocardial perfusion are feasible. However, with 99mTC-labeled sestamibi (99mTC-sestamibi) the optimal clinically relevant demonstration of the superiority of 180- versus 360-degree data acquisition has not been performed. METHODS: Seventy-two consecutive patients undergoing 99mTC-sestamibi imaging at rest and stress who had coronary angiography performed within 3 months were enrolled. The results of blinded interpretation of 13 segments per patient for the 180- and 360-degree data were compared for interobserver variability. Sensitivity and specificity of defect localization in the left anterior descending, right coronary, and left circumflex territories for detection of 50% or greater or 70% or greater stenoses by coronary angiography were compared. RESULTS: There was significant segmental agreement of the stress perfusion images between observers for 180-degree (Kappa = 0.63) and 360-degree data (Kappa = 0.58), but the agreement was significantly higher for 180-degree data (p < 0.05). Overall sensitivity for the detection of coronary artery disease as a 50% or greater stenosis in 62 patients was 79% with 180-degree acquisition and 77% with 360-degree acquisition. The specificity for absence of coronary artery disease in 10 patients was also similar at 70% and 80%, respectively. There was no overall difference in detection of individual stenoses with a sensitivity of 54% with 180-degree acquisition and 50% with 360-degree acquisition. Specificity was also similar at 78% and 81%, respectively. CONCLUSION: There is no difference in clinically relevant detection of overall coronary artery disease or individual stenoses using 180- or 360-degree acquisition of 99mTC-sestamibi myocardial perfusion images. However, 180-degree acquisition has superior interobserver reproducibility.

Coronary Angiography↗