Korean J Radiol.  2000 Sep;1(3):127-134. 10.3348/kjr.2000.1.3.127.

Airway Reactivity to Bronchoconstrictor and Bronchodilator: Assessment Using Thin-Section and Volumetric Three-Dimensional CT

• Han BK
• Im JG
• Kim HS
• Koo JM
• Ki HD
• Yeon KM
• Kim HD

• KMID: 877072
• DOI: http://doi.org/10.3348/kjr.2000.1.3.127

Abstract

OBJECTIVE
To determine the extent to which thin-section and volumetric three-dimensional CT can depict airway reactivity to bronchostimulator, and to assess the effect of different airway sizes on the degree of reactivity. MATERIALS AND METHODS: In eight dogs, thin-section CT scans were obtained before and after the administration of methacholine and ventolin. Cross-sectional areas of bronchi at multiple levels, as shown by axial CT, proximal airway volume as revealed by three-dimensional imaging, and peak airway pressure were mea-sured. The significance of airway change induced by methacholine and ventolin, expressed by percentage changes in cross-sectional area, proximal airway volume, and peak airway pressure was statistically evaluated, as was correlation between the degree of airway reactivity and the area of airways. RESULTS: Cross-sectional areas of the bronchi decreased significantly after the administration of methacholine, and scans obtained after a delay of 5 minutes showed that normalization was insufficient. Ventolin induced a significant increase in cross-sectional areas and an increase in proximal airway volume, while the effect of methacholine on the latter was the opposite. Peak airway pres-sure increased after the administration of methacholine, and after a 5-minute delay its level was near that of the control state. Ventolin, however, induced no significant decrease. The degree of airway reactivity did not correlate with airway size. CONCLUSION: Thin-section and volumetric spiral CT with three-dimensional reconstruction can demonstrate airway reactivity to bronchostimulator. The degree of reactivity did not correlate with airway size.

Keyword

Bronchi, CT; Lung, CT; Lung, effects of drugs on CT, three-dimensional

MeSH Terms

Albuterol/pharmacology
Animal
Bronchoconstriction/*physiology
Bronchoconstrictor Agents/*pharmacology
Bronchodilator Agents/*pharmacology
Dogs
*Imaging, Three-Dimensional
Methacholine Chloride/pharmacology
Tomography, X-Ray Computed/*methods

Figure

• 

  Fig. 1 Diagram of the airway. Symbols (R1-R6, L1-L4) denote specific airway sites where CSAs were measured (R1/ L1: main bronchus; R2/ L2: diaphragmatic bronchus; R3: diaphragmatic bronchus after azygos bronchus; R4: azygos bronchus; R5/ L4: apical bronchus; R6/ L3: lower portion of diaphragmatic bronchus).

• 

  Fig. 2 Mean CSAs of bronchi, as shown by thin-section CT, at multiple sites before and after the administration of drugs. Bronchial CSAs decreased at all sites after the injection of methacholine and increased after the inhalation of ventolin. Symbols from R1 to L4 denote the bronchial sites illustrated in Fig. 1.

• 

  Fig. 3 Thin-section CT scans of a dog at the level of the diaphragmatic bronchi (arrows). A. Cross-sectional area during the control state measures 58 mm2 in the right bronchus, and 50 mm2 in the left. B. CT scan obtained immediately after the injection of methacholine. Note the constriction of the bronchi to 50 mm2 on the right and 38 mm2 on the left. C. CT scan obtained 5 minutes after the injection of methacholine. The bronchi are more dilated than in (B), above. D. CT scan obtained 5 minutes after the inhalation of ventolin shows that the bronchial lumina are more dilated than in (C). The crosssectional area measures 83 mm2 in the right lumen and 66 mm2 in the left.

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  Fig. 4 Shaded surface display of 3-D images of the proximal airway (A: control state; B: immediately after methacholine injection; C: 5-min delay; D: 5 mins after ventolin inhalation). Note the changes in both apical bronchi (arrows) and right lower portion of the diaphragmatic bronchus (arrowheads). Methacholine constricts the airways (B) and ventolin dilates them (D).

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  Fig. 5 Changes in peak airway pressure before and after the administration of drugs. This increased after the injection of methacholine, but showed no significant decrease after the inhalation of ventolin.

Reference

1. Meneely GR, Rensetti AD Jr, Steele JD, Wyatt JP, Harris HW. American Thoracic Society: chronic bronchitis, asthma, and pulmonary emphysema. Am Rev Respir Dis. 1962. 85:762–769.

2. James AL, Pare PD, Hogg JG. The mechanics of airway narrowing in asthma. Am Rev Respir Dis. 1989. 139:242–246.

3. Sekizawa K, Sasaki H, Shimizu Y, Takishima T. Dose-response effects of methacholine in normal and in asthmatic subjects: Relationship between the site of airway response and overall airway hyperresponsiveness. Am Rev Respir Dis. 1986. 133:593–599.

4. Sekizawa K, Yanai M, Shimizu Y, Sasaki H, Takishima T. Serial distribution of bronchoconstriction in normal subjects: Methacholine versus histamine. Am Rev Respir Dis. 1988. 137:1312–1316.

5. Yanai M, Ohrui T, Sekizawa K, Shimizu Y, Sasaki H, Takishima T. Effective site of bronchodilation by antiasthma drugs in subjects with asthma. J Allergy Clin Immunol. 1991. 87:1080–1087.

6. Fish JE, Rosenthal RR, Batra G, et al. Airway responses to methacholine in allergic and nonallergic subjects. Am Rev Respir Dis. 1976. 113:579–586.

7. Orehek J, Gayrard P, Smith AP, Grimaud C, Charpin J. Airway response to carbachol in normal and asthmatic subjects. Am Rev Respir Dis. 1977. 115:937–943.

8. Ingram RH Jr, McFadden ER Jr. Localization and mechanisms of airway responses. N Engl J Med. 1977. 297:596–600.

9. Antic R, Macklem PT. The influence of clinical factors on site of airway obstruction in asthma. Am Rev Respir Dis. 1976. 114:851–859.

10. Brown RH, Herold CJ, Hirshman CA, Zerhouni EA, Mitzner W. In vivo measurements of airway reactivity using high-resolution CT. Am Rev Respir Dis. 1991. 144:208–212.

11. Herold CJ, Brown RH, Mitzner W, Links JM, Hiirshman CA, Zerhouni EA. Assessment of pulmonary airway reactivity with high-resolution CT. Radiology. 1991. 181:369–374.

12. Petak F, Hantos Z, Adamicza A, Asztalos T, Sly PD. Methacholine-induced bronchoconstriction in rats: effects of intravenous vs. aerosol delivery. J Appl Physiol. 1997. 82:1479–1487.

13. Nagase T, Moretto A, Ludwig MS. Airway and tissue behavior during induced constriction in rats: intravenous vs. aerosol administration. J Appl Physiol. 1994. 76:830–838.

14. Amirav I, Kramer SS, Grunstein MM, Hoffman EA. Assessment of methacholine-induced airway constriction by ultrafast high-resolution computed tomography. J Appl Physiol. 1993. 75:2239–2250.

15. Kee ST, Fahy JV, Chen D, Gamsu G. High-resolution computed tomography of airway changes after induced bronchoconstriction and bronchodilation in asthmatic volunteers. Acad Radiol. 1996. 3:389–394.

16. Kim YS, Kim YG, Song IS, et al. Assessment of pulmonary airway reactivity using high-resolution CT after administration of bronchodilator in patients with bronchial asthma. J Korean Radiol Soc. 1994. 31:69–73.

17. Troyer A, Yernault J-C, Rodenstein D. Effects of vagal blockade on lung mechanics in normal man. J Appl Physiol. 1979. 46:217–226.

18. Woolcock AJ, Macklem PT, Hogg JC, et al. Effect of vagal stimulation on central and peripheral airways in dogs. J Appl Physiol. 1969. 25:806–813.

19. Drazen JM, Schneider MW. Comparative response of tracheal spiral and parenchymal strips to histamine and carbachol. J Clin Invest. 1977. 61:1441–1447.

20. Nadel JA, Cabezas GA, Austin JHM. In vivo roentgenographic examination of parasympathetic innervation of small airways: use of powdered tantalum and a fine focal spot x-ray tube. Invest Radiol. 1971. 6:9–17.

21. Shioya T, Solway J, Munoz NM, Mack M, Leff AR. Distribution of airway contractile responses within the major diameter bronchi during exogenous bronchoconstriction. Am Rev Respir Dis. 1987. 135:1105–1111.

22. Benson MK, Graf PDD. Bronchial reactivity: interaction between vagal stimulation and inhaled histamine. J Appl Physiol. 1977. 43:643–647.

23. Grenire P, Cordeau MP, Beigelman C. High-resolution CT of the airways. J Thorac Imag. 1993. 8:213–229.

24. Zerhouni EA, Herold CJ, Brown RH, et al. High-resolution CT-physiologic correlation. J Thorac Imag. 1993. 8:265–272.

25. Curry JJ. Comparative action of acetyl-beta-methyl choline and histamine on the respiratory tract in normals, patients with hay fever, and subjects with bronchial asthma. J Clin Invest. 1947. 26:430–438.

26. Wood SA, Zerhouni EA, Hoford JD, Hoffman EA, Mitzner W. Measurement of three-dimensional lung tree structures by using computed tomography. J Appl Physiol. 1995. 79:1687–1697.