Volume 144, Issue 3, Pages 940-946 (September 2013) A New Method to Detect Air Leakage in a Patient With Pneumothorax Using Saline Solution and Multidetector-Row Spiral CT Scan  Kozo Nakanishi, MD, PhD, Akihiro Shimotakahara, MD, PhD, Yuko Asato, MD, PhD, Toshihiro Ishihara  CHEST  Volume 144, Issue 3, Pages 940-946 (September 2013) DOI: 10.1378/chest.12-2678 Copyright © 2013 The American College of Chest Physicians Terms and Conditions

Figure 1 Foam and wave shadow on saline-filled thoracography CT scan and its surgical finding (case 1). A1, Coronal section and magnified view. A2, Supine position. Multiple round low-attenuation areas are shown in the injected saline around the apical lung. These grouped multiple round shadows have the appearance of foam. B1, Axial section, supine; surface of saline water injected into the pleural cavity was not flat but a “wave form.” B2, Magnified view of Figure B1; a bulla was seen at the visceral pleura of the apical lung near the wave-shaped shadow. C, Surgical air-leak test. Air bubbles are blown out from a small fistula of the apical bulla. CHEST 2013 144, 940-946DOI: (10.1378/chest.12-2678) Copyright © 2013 The American College of Chest Physicians Terms and Conditions

Figure 2 Culprit bulla and foam/wave shadows in another case (case 2). A, A bulla and a wave shadow on the surface of the injected saline can be seen on the axial section of the saline-filled CT images. B, Foam shadows are shown on a coronal view reconstructed from multidetector-row spiral CT scan volume data. CHEST 2013 144, 940-946DOI: (10.1378/chest.12-2678) Copyright © 2013 The American College of Chest Physicians Terms and Conditions

Figure 3 Culprit bulla and bubble shadows forming foam shadows (case 4). A, Coronal section, supine position, before saline injection. B, Coronal section, supine position, saline-filled CT scan. The view and position of Slice 0 have been adjusted to be nearest to those of A. A bulla (arrowhead) can be seen at the lateral side of the left upper lung before saline injection (A). A bulla and a few bubble shadows can be seen on the most posterior layer of the saline-filled CT images (B, Slice 0). According to the anterior layers (B, Slices 1-3), bubble shadows were increasing and spreading to the saline water surface. Judging from the appearance and location of the two bullae marked with black triangles in A and B Slice 0, they should be identical. We were able to determine that the bulla must be the culprit lesion of the air leakage. CHEST 2013 144, 940-946DOI: (10.1378/chest.12-2678) Copyright © 2013 The American College of Chest Physicians Terms and Conditions

Figure 4 Air-fluid level in bulla, infiltrative shadow, “spout” shadow, and other radiologic findings in a patient with secondary pneumothorax (case 8). A, Axial view, lateral position, before saline injection. B, Axial view, lateral position, saline-filled CT scan. Three major bullae (α, β, and γ) are shown in A and B. The pleural space was aerially connected to bulla-γ1 through two defects (arrowheads) of the wall of bulla-α (A1). This indicated that there was an aerial pathway from bulla-γ to the pleural space through bulla-α. The low-density area of γ1 was connecting to the γ2 part (A1-5). An infiltrative shadow was seen in the lung parenchyma near bulla-γ, in which the air-fluid level was shown (B5). It reflects saline aspirated into the lung through bulla-γ. The air-fluid level was also shown in bulla-α on the pathway (B1, 2). There were no findings of air leaks in or near bulla-β (B1-5). Air leaking to the pleural space should originate from the lung parenchyma near bulla-γ and may not pass through bulla-β. A hypertranslucent stripe and radial artifacts were seen along the aerial pathway (B1-4). At the pleural end of the stripe, the wall of bulla-α was obscured (B1, 2). The shadow had the appearance of a water spout or fire (B1). Surgical findings revealed that air and saline in the bulla were entering the pleural space like a water spout. CHEST 2013 144, 940-946DOI: (10.1378/chest.12-2678) Copyright © 2013 The American College of Chest Physicians Terms and Conditions

Figure 5 Surgical findings of the left apical lung of case 8. Surgical view (on the left is the anterior of the patient). A, Apical view before bulla resection. Two bullae (α and β, which are radiologically shown as bulla-α and β in Fig 4) can be seen in this viewpoint. Thin-walled bulla-α had a large fistula (arrowhead) and adhered to the apical chest wall. B, Apical view after cutting a part of the wall of bulla-α (asterisks). Another large fistula (arrowhead) was exposed, and the apical lung near the bulla collapsed. Nevertheless, bulla-β was still expansive. CHEST 2013 144, 940-946DOI: (10.1378/chest.12-2678) Copyright © 2013 The American College of Chest Physicians Terms and Conditions

Figure 6 Collapsed bulla (case 9). A, An expanded bulla was seen among the middle and lower lobes in the supine position. B, The bulla was collapsed after the postural change. The lower lobe was collapsed and infiltrative shadows were seen in the lower lobe (B). The bulla should arise on the lower lobe. CHEST 2013 144, 940-946DOI: (10.1378/chest.12-2678) Copyright © 2013 The American College of Chest Physicians Terms and Conditions