Journal article
Limitations of Kr-81m for quantitation of ventilation scans
The Journal of nuclear medicine (1978), Vol.23(4), pp.301-305
04/1982
PMID: 7069493
Abstract
Predictions of Kr-81m behavior in the lungs have been based on a single-compartment model of well-mixed gas. To determine the validity of this model, anesthetized, paralyzed dogs were ventilated mechanically over a wide range of ventilations with Kr-81m in the inspirate. Averaged data obtained from 1.5- to 2-min images were compared with the model's predictions. Krypton-81m concentration appeared more linearly related to ventilation than the model predicts. This suggests that the Kr-81m may not be distributed to the entire resident gas volume or that its distribution changes with lung volume. Estimation of end-expiratory volume (FRC)--based on the tidal volume and the maximum-to-minimum count ratio over the lung during gated acquisitions--underestimated the true FRC by about 40%. The magnitude of error depended upon the combination of tidal volume and frequency and the inspiratory time. Thus, Kr-81m does not mix well with resident lung gas, and the well-mixed, single-compartment model is not a good predictor of Kr-81m behavior in the lung.
Details
- Title: Subtitle
- Limitations of Kr-81m for quantitation of ventilation scans
- Creators
- H I ModellM M Graham
- Resource Type
- Journal article
- Publication Details
- The Journal of nuclear medicine (1978), Vol.23(4), pp.301-305
- Publisher
- United States
- PMID
- 7069493
- ISSN
- 0161-5505
- eISSN
- 1535-5667
- Language
- English
- Date published
- 04/1982
- Academic Unit
- Radiology; Radiation Oncology
- Record Identifier
- 9984046816002771
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