Visual score and quantitative CT indices in pulmonary fibrosis: Relationship with physiologic impairment

Abstract

The visual score is still the main radiological method of quantifying the extent of abnormalities in patients with UIP, whilst the range of density 700 to 400 HU can be helpfully applied in a predominant pattern of ground-glass and reticular opacities without honeycombing.

Lung densitometry: why, how and when

“…Not surprisingly, because of the intrinsically continuous nature of the densitometry indexes shared with PFT, as opposed to the categorical nature of visual scores, in some studies of the above conditions the degree of correlation of densitometric parameters exceeded that of visual semi-quantitative rating (20,21). However, the degree of correlation of lung density measurements with PFT in idiopathic pulmonary fibrosis (IPF) is generally lower and similar to that of visual score (41)(42)(43)(44)(45)(46).…”

“…Mean lung attenuation (MLA) is the simplest measurement which is utilized especially for pulmonary fibrosis (21,(40)(41)(42)(43)(44)46), but also for estimation of emphysema extent (24,26,28,32,35). MLA is not a sensitive index and other histogram-based indexes are typically used for quantification with densitometry of emphysema and pulmonary fibrosis.…”

Evaluating disease severity in idiopathic pulmonary fibrosis

“…Methods vary from simple histogram analysis to more complex forms of textural based analysis and machine learning. In the former, histogram-based measurements such as mean lung attenuation and amount of skewness and kurtosis from CT images have been found to correlate with physiological measures of disease severity [46,[70][71][72].…”

Density-based MDCT quantification of lobar lung volumes: a study of inter- and intraobserver reproducibility

“…By applying a predetermined density threshold to the volumetric acquisition of MDCT, the voxels corresponding to lung tissue can be isolated [12]. The percentage distribution of the densities of selected voxels can be represented on a histogram and a density range of -1024/-950 HU can be used to estimate the relative fraction of emphysema.…”

“…Dall'acquisizione volumetrica ottenibile con gli apparecchi MDTC, applicando soglie densitometriche predefinite, si possono isolare i voxel che rappresentano il parenchima polmonare [12]. L'istogramma della distribuzione percentuale delle densità dei voxel selezionati consente di stimare la percentuale relativa di enfisema, restringendo la misurazione al range di densità di -1024/-950 unità Hounsfield (HU).…”