Krypton ventilation imaging using dual-energy CT in chronic obstructive pulmonary disease patients: initial experience.
Radiology
; 263(1): 253-9, 2012 Apr.
Article
em En
| MEDLINE
| ID: mdl-22332068
ABSTRACT
PURPOSE:
To evaluate the tolerance and level of enhancement achievable after inhalation of stable krypton. MATERIALS ANDMETHODS:
This study was approved by the institutional review board and the local ethics committee. Written informed consent was obtained from all subjects. The study was planned as a Fleming two-stage design, enabling one to assess the effectiveness of a newer treatment or technique on a small number of patients. At the end of each stage, the results are computed, and the trial can be stopped if the effectiveness is less than a minimum success rate or greater than an expected success rate. After informed consent was obtained, a total of 32 patients (ie, two successive series of 16 patients each) with severe emphysema underwent a dual-source, dual-energy chest computed tomographic (CT) examination after inhalation of a mixture of stable krypton (80%) and oxygen (20%), with reconstruction of diagnostic and ventilation images. For each patient, two regions of interest were selected on a diagnostic image, one in a region of severe emphysema (presumed to be poorly ventilated or not ventilated) and a second one in a region devoid of structural abnormalities (presumed to be normally ventilated), with measurements of attenuation values on the corresponding ventilation image.RESULTS:
All examinations were successfully performed, without adverse effects. Differences in attenuation between normal lung and emphysematous areas were found in 28 patients (88%; 95% confidence interval 71%, 96.5%). The maximal level of attenuation within normal lung was 18.5 HU. Krypton attenuation difference between normal and emphysematous lung was significant, with a median value of 51.8% (P < .001).CONCLUSION:
The level of enhancement after inhalation of krypton and its excellent clinical tolerance makes this gas eligible for ventilation CT examinations.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Tomografia Computadorizada por Raios X
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Doença Pulmonar Obstrutiva Crônica
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Criptônio
Limite:
Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Radiology
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
França