The Comet-tail Artifact

Abstract

Can ultrasound be of any help in the diagnosis of alveolar-interstitial syndrome? In a prospective study, we examined 250 consecutive patients in a medical intensive care unit: 121 patients with radiologic alveolar-interstitial syndrome (disseminated to the whole lung, n = 92; localized, n = 29) and 129 patients without radiologic evidence of alveolar-interstitial syndrome. The antero-lateral chest wall was examined using ultrasound. The ultrasonic feature of multiple comet-tail artifacts fanning out from the lung surface was investigated. This pattern was present all over the lung surface in 86 of 92 patients with diffuse alveolar-interstitial syndrome (sensitivity of 93.4%). It was absent or confined to the last lateral intercostal space in 120 of 129 patients with normal chest X-ray (specificity of 93.0%). Tomodensitometric correlations showed that the thickened sub-pleural interlobular septa, as well as ground-glass areas, two lesions present in acute pulmonary edema, were associated with the presence of the comet-tail artifact. In conclusion, presence of the comet-tail artifact allowed diagnosis of alveolar-interstitial syndrome.

Comparison of a basic lung scanning protocol against formally reported chest x‐ray in the diagnosis of pulmonary oedema

“…The sonographic artefact was originally named a ‘comet‐tail’ artefact, and indicated an area that would show either interstitial markings or ‘ground glass’ changes on chest x‐ray. These were first described by Lichtenstein 23 , 24 using chest x‐ray as a reference, and subsequently confirmed with region by region comparison using CT scanning as the reference standard 22 …”

Incremental value of thoracic ultrasound in intensive care units: Indications, uses, and applications

“…Lung sliding is prevented due to this interposition, as ultrasound cannot pass across the air present in the pleural space due to lung disease. Moreover, B-lines are no longer visible, while the only visible A-lines are horizontal [23] . Several studies have recently confirmed that bedside TUS is more specific than CR in the diagnosis of PNT in critically ill patients [21,[52][53][54] .…”

“…Most of the diagnostic procedures of TUS concern the anterior wall, as well as lateral parts of the chest cage. The anterior wall is delimitated from the sternum to the anterior axillary row, the lateral wall is delimitated from the anterior to the posterior axillary row, and the posterior wall is delimitated from the paravertebral row, the scapular row, and the posterior axillary row [11,[22][23][24] . Thoracic parts are obviously the same in both areas, but the presence of the heart on the left side reduces helpful scansion in that area.…”

“…They are well-defined, laser-like, hyperechoic, and erase A-lines [26] . In the normal lung, there are generally no more than 2-3 vertical artifacts per chest part per hemithorax, and they are typically at the base of the lung [11,23,27] ; these are named B-lines or comet tails ( Figure 5) [12,28,29] . B-line images are connected via a small water-rich structure under the resolution of the sonographic beam enclosed by air, with artifacts being generated when said structure is struck by an ultrasound beam.…”

“…It is important to remember, as previously stated, that one or two B-lines may be viewed ordinarily in bottom- Liccardo B et al . Thoracic ultrasound in ICU dependent lung regions, such as normally-aerated lung bases [23] . It has been demonstrated that most B-lines nearer than 7 mm are determined by thickened interlobular septa with interstitial edema, while most B-lines that are 3 mm or less are produced by alveolar edema.…”