Dynamic pulmonary CT: findings in healthy adult men.

Webb, W. Richard; Stern, Eric J.; Kanth, Nalini; Gamsu, G

doi:10.1148/radiology.186.1.8416550

Cited by 177 publications

(96 citation statements)

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“…From 90% VC to 10% VC, the mean lung density increased by 80 HU in the upper zones of the lungs and 86 HU in the lower zones. This is much less than reported by WEBB et al [18], who found an increase in attenuation of 200 HU in healthy volunteers. Our numbers are more consistent with air-trapping and are a reflection of the study population, in which patients with COPD are well represented.…”

Section: Discussioncontrasting

confidence: 59%

Reproducibility of spirometrically controlled CT lung densitometry in a clinical setting

Lamers

Kemerink²,

Drent³

et al. 1998

Eur Respir J

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aaDensitometry of the lung is extensively used in pulmonary research. It has the potential to become an important addition to standard lung function tests in diagnosing and following the extent of pulmonary emphysema and interstitial lung disease. For recent reviews of this extensive work we refer to the literature [1,2]. The value of the technique is clearly proven in pulmonary emphysema. During inspiration, computed tomography (CT) correlates well with the pathologic score of emphysema [3]. Expiratory CT reflects airway obstruction and air-trapping more than it does emphysema [4,5]. Densitometric data may contribute to improved patient selection and to better evaluation of the response to volume reduction surgery [6,7]. Densitometry may provide an additional measure in selecting the side of greatest severity for unilateral lung reduction surgery [7].The methodologogy of CT densitometry has been established as well as factors affecting parameters derived from a histogram of Hounsfield units (HU). The accuracy and conformity of modern CT scanners have proved to be adequate after correction for poor air calibration [8,9]. CT number histograms of the lung are strongly dependent on section thickness and reconstruction filter [10][11][12]. To optimize CT evaluation procedures, semi-automatic algorithms isolating lung parenchyma by fast contour tracking have been developed, as well as automatic evaluation algorithms calculating various densitometric parameters automatically. Usually, mean lung density is determined as an average over a relatively large area. Unfortunately, it can be spuriously misleading especially at localized disease onset [13]. Mean lung density, however, is not the only densitometric parameter which can be extracted from the CT data. Pixel index analysis [3,4,14] and the lowest 10th percentile of the frequency distribution of densities [15] have shown promising results in the assessment of emphysema.If densitometry of the lung is used for diagnosis and follow-up of pulmonary emphysema or interstitial lung disease, the overall precision of the procedure has to be established. Reproducibility errors due to instrumental and technical factors have generally been considered to be smaller than patient-related factors. The CT density of the lung is considerably influenced by the level of inspiration at which the CT images are obtained. Control and monitoring this level of inspiration during scanning is of major importance to obtain reproducible CT lung density measurements. A spirometrically controlled CT technique has been developed, offering the opportunity to obtain CT scans at defined levels of inspiration [16].The purpose of this study was to assess the reproducibility of a number of histogram-related parameters of single CT slices through the upper and the lower zones of the lungs at 90 and 10% of the vital capacity (VC) in a hospitalized patient population. Reproducibility of spirometrically controlled CT lung desitometry in a clinical setting. R.J.S. Lamers, G.J. Kemerink, M. Drent, J.M.A. van E...

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Section: Discussioncontrasting

confidence: 59%

Reproducibility of spirometrically controlled CT lung densitometry in a clinical setting

Lamers

Kemerink²,

Drent³

et al. 1998

Eur Respir J

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“…The relatively opaque normal lung willincrease in attenuation and decrease in volume, as expected [6]. In primary vascular lung disease, because there is no air trapping or airway disease, the attenuation of both the hyperemic and oligemic lung at inspiration will increase in a similar fashion, and the volume of both will pare the different regions of lung attenuation for changes between inspiration and expiration, but occasionally it will be helpful to quantitatively compare the Hounsfield measurements of lower-attenuation and higher-attenuation areas of lung in scans obtained at inspiration and at expiration (Fig.…”

Section: Discussionmentioning

confidence: 53%

CT mosaic pattern of lung attenuation: distinguishing different causes.

Stern¹,

Swensen²,

Hartman³

et al. 1995

American Journal of Roentgenology

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114

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Areas of variable lung attenuation in a lobular or multilobular distribution are occasionally seen on CT or high-resolution CT scans of the lungs [1], although never as a normal finding. This mosaic pattern of lung attenuation presents a challenge to the radiologist when deciding which are the abnormal regions of lung-those of low attenuation, those of high attenuation, or both. We have observed three categories of disease known to cause a CT mosaic pattern of lung attenuation: small-airway disease, vascular lung disease, and infiltrative disease. Diseases from each of these categories can cause similar patterns of mosaic lung attenuation on CT scans. However, it is sometimes possible to distinguish among these categories by using additional CT findings. We illustrate the known causes of a CT mosaic pattern of lung attenuation and highlight distinguishing features.

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“…The question of the importance, or otherwise, of focal areas of low attenuation consisting of one or more secondary pulmonary lobules has persisted since such "abnormalities" were reported on dynamic expiratory CT in four out of 10 apparently healthy volunteers with normal pulmonary function tests [108]. Such areas of decreased attenuation are not usually present or conspicuous on inspiratory HRCTs of normal individuals [102] and, when identified, need to be distinguished from artefactual areas of low density caused by adjacent ribs (beam hardening artefact).…”

Section: Accuracy Of High-resolution Computed Tomography Signs and Inmentioning

confidence: 99%

Small airways diseases: detection and insights with computed tomography

Dm¹

2001

Eur Respir J

145

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Diseases affecting the small airways are difficult to detect by traditional diagnostic tests. Widespread involvement is needed before symptoms and abnormalities on pulmonary function testing or chest radiography become apparent. Obstruction of the bronchioles may be detected indirectly by computed tomography (CT) because regional under-ventilation results in reduced perfusion which in turn is shown as a mosaic attenuation pattern of the lung parenchyma. When there is inflammation of the bronchioles with accompanying exudate, the airways may become directly visible on CT, for example in cases of diffuse panbronchiolitis.Quantification of the various morphological features of small airways disease is possible from CT images and this increased precision has aided investigations of structure/function relationships.An understanding of the pathology and microscopic distribution of disease in relation to the airways allows some prediction of the likely computed tomography appearances in this wide spectrum of conditions, and thus helps to refine the differential diagnosis.

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Dynamic pulmonary CT: findings in healthy adult men.

Cited by 177 publications

References 0 publications

Reproducibility of spirometrically controlled CT lung densitometry in a clinical setting

Reproducibility of spirometrically controlled CT lung densitometry in a clinical setting

CT mosaic pattern of lung attenuation: distinguishing different causes.

Small airways diseases: detection and insights with computed tomography

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