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Effects of contrast material on computed tomographic measurements of lung volumes in patients with acute lung injury.

Bouhemad B, Richecoeur J, Lu Q, Malbouisson LM, Cluzel P, Rouby JJ, ARDS CT Scan Study Gro - Crit Care (2002)

Bottom Line: Volumes of gas and tissue, and volumic distribution of CT attenuations were measured before and after injection using specially designed software (Lungview; Institut National des Télécommunications, Evry, France).The maximal artifactual increase in lung tissue resulting from a hypothetical leakage within the lung of the 80 ml contrast material was calculated.Injection of contrast material significantly increased the apparent volume of lung tissue by 83 +/- 57 ml in group 1 and 102 +/- 80 ml in group 2, whereas the corresponding maximal artifactual increases in lung tissue were 42 +/- 52 ml and 31 +/- 18 ml.

View Article: PubMed Central - PubMed

Affiliation: Clinique en Réanimation Chirurgicale Pierre Viars (Department of Anaesthesiology), Hospital Pitié-Salpêtrière, University of Paris VI, Paris, France.

ABSTRACT

Background: Intravenous injection of contrast material is routinely performed in order to differentiate nonaerated lung parenchyma from pleural effusion in critically ill patients undergoing thoracic computed tomography (CT). The aim of the present study was to evaluate the effects of contrast material on CT measurement of lung volumes in 14 patients with acute lung injury.

Method: A spiral thoracic CT scan, consisting of contiguous axial sections of 10 mm thickness, was performed from the apex to the diaphragm at end-expiration both before and 30 s (group 1; n = 7) or 15 min (group 2; n = 7) after injection of 80 ml contrast material. Volumes of gas and tissue, and volumic distribution of CT attenuations were measured before and after injection using specially designed software (Lungview; Institut National des Télécommunications, Evry, France). The maximal artifactual increase in lung tissue resulting from a hypothetical leakage within the lung of the 80 ml contrast material was calculated.

Results: Injection of contrast material significantly increased the apparent volume of lung tissue by 83 +/- 57 ml in group 1 and 102 +/- 80 ml in group 2, whereas the corresponding maximal artifactual increases in lung tissue were 42 +/- 52 ml and 31 +/- 18 ml.

Conclusion: Because systematic injection of contrast material increases the amount of extravascular lung water in patients with acute lung injury, it seems prudent to avoid this procedure in critically ill patients undergoing a thoracic CT scan and to reserve its use for specific indications.

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Related in: MedlinePlus

Three representative mediastinal (upper panels) and parenchymal (lower panels) windows of computed tomography (CT) sections obtained before (baseline), and 30 s and 15 min after injection of contrast material in one patient. At 30 s, both lung parenchyma and pulmonary vessels are opacified. At 15 min, contrast material can be observed only in the lung parenchyma. The black line delineates lung parenchyma (accentuated contrast after injection of contrast material) from pleural effusion (same contrast after injection of contrast material).
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Figure 2: Three representative mediastinal (upper panels) and parenchymal (lower panels) windows of computed tomography (CT) sections obtained before (baseline), and 30 s and 15 min after injection of contrast material in one patient. At 30 s, both lung parenchyma and pulmonary vessels are opacified. At 15 min, contrast material can be observed only in the lung parenchyma. The black line delineates lung parenchyma (accentuated contrast after injection of contrast material) from pleural effusion (same contrast after injection of contrast material).

Mentions: Table 2 shows the CT number of pulmonary arteries before and after injection of contrast material. The pulmonary arterial concentration of contrast material ranged between 0.3% and 2% at 30 s after the injection, and between 0% and 0.07% at 15 min after the injection. Figs. 2 shows 3 representative CT sections acquired in one patient at baseline, 30 s and 15 min following injection of contrast material. Pulmonary vessels were opacified by contrast material only on the CT sections taken 30 s after injection, whereas lung parenchyma was opacified on CT sections taken 30 s and 15 min after injection. The corresponding apparent volumes of lung tissue were 1445 ml (baseline), 1555 ml (30 s) and 1553 ml (15 min).


Effects of contrast material on computed tomographic measurements of lung volumes in patients with acute lung injury.

Bouhemad B, Richecoeur J, Lu Q, Malbouisson LM, Cluzel P, Rouby JJ, ARDS CT Scan Study Gro - Crit Care (2002)

Three representative mediastinal (upper panels) and parenchymal (lower panels) windows of computed tomography (CT) sections obtained before (baseline), and 30 s and 15 min after injection of contrast material in one patient. At 30 s, both lung parenchyma and pulmonary vessels are opacified. At 15 min, contrast material can be observed only in the lung parenchyma. The black line delineates lung parenchyma (accentuated contrast after injection of contrast material) from pleural effusion (same contrast after injection of contrast material).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC154113&req=5

Figure 2: Three representative mediastinal (upper panels) and parenchymal (lower panels) windows of computed tomography (CT) sections obtained before (baseline), and 30 s and 15 min after injection of contrast material in one patient. At 30 s, both lung parenchyma and pulmonary vessels are opacified. At 15 min, contrast material can be observed only in the lung parenchyma. The black line delineates lung parenchyma (accentuated contrast after injection of contrast material) from pleural effusion (same contrast after injection of contrast material).
Mentions: Table 2 shows the CT number of pulmonary arteries before and after injection of contrast material. The pulmonary arterial concentration of contrast material ranged between 0.3% and 2% at 30 s after the injection, and between 0% and 0.07% at 15 min after the injection. Figs. 2 shows 3 representative CT sections acquired in one patient at baseline, 30 s and 15 min following injection of contrast material. Pulmonary vessels were opacified by contrast material only on the CT sections taken 30 s after injection, whereas lung parenchyma was opacified on CT sections taken 30 s and 15 min after injection. The corresponding apparent volumes of lung tissue were 1445 ml (baseline), 1555 ml (30 s) and 1553 ml (15 min).

Bottom Line: Volumes of gas and tissue, and volumic distribution of CT attenuations were measured before and after injection using specially designed software (Lungview; Institut National des Télécommunications, Evry, France).The maximal artifactual increase in lung tissue resulting from a hypothetical leakage within the lung of the 80 ml contrast material was calculated.Injection of contrast material significantly increased the apparent volume of lung tissue by 83 +/- 57 ml in group 1 and 102 +/- 80 ml in group 2, whereas the corresponding maximal artifactual increases in lung tissue were 42 +/- 52 ml and 31 +/- 18 ml.

View Article: PubMed Central - PubMed

Affiliation: Clinique en Réanimation Chirurgicale Pierre Viars (Department of Anaesthesiology), Hospital Pitié-Salpêtrière, University of Paris VI, Paris, France.

ABSTRACT

Background: Intravenous injection of contrast material is routinely performed in order to differentiate nonaerated lung parenchyma from pleural effusion in critically ill patients undergoing thoracic computed tomography (CT). The aim of the present study was to evaluate the effects of contrast material on CT measurement of lung volumes in 14 patients with acute lung injury.

Method: A spiral thoracic CT scan, consisting of contiguous axial sections of 10 mm thickness, was performed from the apex to the diaphragm at end-expiration both before and 30 s (group 1; n = 7) or 15 min (group 2; n = 7) after injection of 80 ml contrast material. Volumes of gas and tissue, and volumic distribution of CT attenuations were measured before and after injection using specially designed software (Lungview; Institut National des Télécommunications, Evry, France). The maximal artifactual increase in lung tissue resulting from a hypothetical leakage within the lung of the 80 ml contrast material was calculated.

Results: Injection of contrast material significantly increased the apparent volume of lung tissue by 83 +/- 57 ml in group 1 and 102 +/- 80 ml in group 2, whereas the corresponding maximal artifactual increases in lung tissue were 42 +/- 52 ml and 31 +/- 18 ml.

Conclusion: Because systematic injection of contrast material increases the amount of extravascular lung water in patients with acute lung injury, it seems prudent to avoid this procedure in critically ill patients undergoing a thoracic CT scan and to reserve its use for specific indications.

Show MeSH
Related in: MedlinePlus