A simple technique is described for producing high-quality functional images of regional ventilation during physiological tidal breathing of the inert gas 81mKr. These images are quickly obtained on a gamma-camera without the need of computerized systems for data acquisition and display and are directly comparable with those of perfusion obtained with 99mTc-labelled macroaggregates. The short time required for the procedure, its simplicity, and the extremely low absorbed-radiation dose enable serial images of ventilation to be obtained in multiple views.

https://www.bmj.com/content/bmj/3/5985/673.full.pdf

Assessment of regional ventilation by continuous inhalation of radioactive krypton-81m

Electrical impedance tomography (EIT) is a technique that makes it possible to measure ventilation and pulmonary perfusion in a volume that approximates to a 2D plane. The possibility of using EIT for measuring the left-right division of ventilation and perfusion was compared with that of radionuclide imaging. Following routine ventilation (81mKr) and perfusion scanning (99mTc-MAA), EIT measurements were performed at the third and the sixth intercostal level in 14 patients with lung cancer. A correlation (r = 0.98, p < 0.005) between the left-right division for the ventilation measured with EIT and that with 81mKr was found. For the left-right division of pulmonary perfusion a correlation of 0.95 (p < 0.005) was found between the two methods. The reliability coefficient (RC) was calculated for estimating the left-right division with EIT. The RC for the ventilation measurements was 94% and 96% for the perfusion measurements. The correlation analysis for reproducibility of the EIT measurements was 0.95 (p < 0.001) for the ventilation and 0.93 (p < 0.001) for the perfusion measurements. In conclusion, EIT can be regarded as a promising technique to estimate the left-right division of pulmonary perfusion and ventilation.

https://iopscience.iop.org/article/10.1088/0967-3334/19/4/003/pdf

Ventilation and perfusion imaging by electrical impedance tomography : a comparison with radionuclide scanning

Differences in regional wash-in and wash-out time constants for xenon-CT ventilation studies.

Pulmonary deposition of aerosols in children with cystic fibrosis.

With the emergence of multidetector-row computed tomography (CT) it is now possible to image both structure and function via use of a single imaging modality. Breath-hold spiral CT provides detail of the airway and vascular trees along with texture reflective of the state of the lung parenchyma. Use of stable xenon gas wash-in and/or wash-out methods using an axial mode of the CT scanner whereby images are acquired through gating to the respiratory cycle provide detailed images of regional ventilation with isotropic voxel dimensions now on the order of 0.4 mm. Axial scanning during a breath hold and gating to the electrocardiogram during the passage of a sharp bolus injection of iodinated contrast agent provide detailed images of regional pulmonary perfusion. These dynamic CT methods for the study of regional lung function are discussed in the context of other methods that have been used to study heterogeneity of lung function.

/pdf/computed-tomography-studies-of-lung-ventilation-and-1nnwhyvugk.pdf

Computed tomography studies of lung ventilation and perfusion.

http://jnm.snmjournals.org/content/14/10/725.full.pdf

The measurement of regional ventilation in man: a new method of quantitation.

Ventilation-Perfusion Scanning in Carcinoma of the Bronchus

Regional ventilation has been measured in 17 healthy volunteers, and 24 patients with chronic obstructive lung disease during tidal breathing using 133Xe. The wash-in and wash-out of 133Xe were recorded by a gamma camera interfaced to a small digital computer. Regional ventilation was calculated as the distribution of tidal volume per unit lung volume—a measure of relative ventilation—and from the wash-out curves as the fractional exchange of air per second. Determination of the regional fractional exchange of air showed a significant difference between the patients with chronic obstructive lung disease and normal subjects for all regions. The distribution of tidal volume per unit lung volume did not effect such a clear separation. Significant correlations were found between the wholelung fractional exchange of air in the patients with chronic obstructive lung disease and their FEV1 r=0·70, MMFR r=0·70, FVC r=0·56 and FEV1/FVC r=0·57. It is suggested that measurement of regional ventilation as th...

The measurement of regional ventilation during tidal breathing: a comparison of two methods in healthy subjects, and patients with chronic obstructive lung disease

Regional ventilation-perfusion ratios have been determined in 12 healthy subjects, 16 patients with pulmonary embolism, and 22 patients with chronic obstructive lung disease. The ventilation-perfusion

J. Wilhelm

Papers

The measurement of regional ventilation in man: a new method of quantitation.

Ventilation-Perfusion Scanning in Carcinoma of the Bronchus

The measurement of regional ventilation during tidal breathing: a comparison of two methods in healthy subjects, and patients with chronic obstructive lung disease

Regional ventilation-perfusion relationships.