Costal pleura: appearances at high-resolution CT.

Abstract

The appearance of the costal pleura at high-resolution computed tomography (CT) was evaluated with a cadaver and 25 normal subjects. This was contrasted with the high-resolution CT appearance of the costal pleura in 15 patients with mild pleural thickening, 13 of whom had been exposed to asbestos. On high-resolution CT scans in the normal subjects, a 1-2-mm-thick line of soft-tissue attenuation at the point of contact between lung and chest wall represents the visceral and parietal pleura, pleural contents, endothoracic fascia, and innermost intercostal muscle. In a paravertebral location, the innermost intercostal muscle is lacking, and a thin line seen on high-resolution CT scans reflects pleura and endothoracic fascia. Transverse thoracic and subcostal muscles and extrapleural fat pads can be seen as tissue internal to a rib and may be confused with pleural thickening. In 13 of the 15 patients with mild pleural thickening, the 1-3-mm-thick pleura was separable from the underlying normal intercostal muscle by a layer of extrapleural fat. High-resolution CT was more sensitive than CT with 1-cm collimation in depicting this degree of pleural abnormality.

Diagnostic Utility and Clinical Application of Imaging for Pleural Space Infections

“…In health, imaging studies cannot visualize the pleural space against the diaphragm and chest wall 3 because pleural membranes are only 0.2 to 0.4 mm thick and physiologic volumes (4 to 18 mL) 4 of pleural fl uid form a thin 5-to 10-m m layer. 5 The invaginations of visceral pleura composing the interlobar and accessory fi ssures appear as linear or curvilinear lines.…”

“…A high-frequency linear transducer (5-7.5 MHz) provides high-resolution intercostal scanning, but is limited in penetration for patients with thick chest walls and does not provide a large fi eld of view for visualization of the pleural space and underlying lung. 7 For most patients, a convex or sector transducer of intermediate frequency (3)(4) provides the best compromise between near-fi eld resolution of the lung-pleura interface, a wider evaluation of large effusions, and assessment of the parietal pleura and lung parenchyma. 8 -10 Normal pleural membranes are too thin to be visualized even by high-resolution ultrasonography.…”

“…7 CT scan cannot visualize normal pleura against the chest wall because pleural membranes blend in with endothoracic fascia and intercostal muscles. 3 In the paravertebral regions, a thin line representing the pleural layers and pleural space may be visible because the innermost intercostal muscle is absent in this region. The interlobar and accessory fi ssures are visible in cross section as curvilinear opacities on thin-section axial, sagittal, and coronal reformatted images.…”

Massive Traumatic Extrapleural Hematoma Mimicking Hemothorax: A Potential Pitfall of Penetrating Chest Trauma

“…The combined thickness of the normal visceral and parietal pleurae is only 0.2 to 0.4 mm. 8 Thus, these two structures together with the extrapleural fat layer may not be visible on conventional CT and may only be demonstrated when they are diseased and thickened. The pathognomonic finding of extrapleural hematoma as demonstrated on CT is the 'displaced extrapleural fat' sign.…”

Chest wall infiltration by lung cancer: value of thin-sectional CT with different reconstruction algorithms

“…This covers the whole contact area of the lesion. In accordance with the study by Im et al [24] we used a high-resolution algorithm with a window setting adapted to the soft tissue. In contrast to examinations of the lung parenchyma, the narrowed window emphasizes the disadvantage of this algorithm in the form of high image noise and artifacts at the border between structures of high-density difference as it is given at the pleura [19,20,23,25].…”