Evaluation of quantitative CT indexes in idiopathic interstitial pneumonitis using a low-dose technique.
OBJECTIVE
To evaluate and compare histogram features (mean lung attenuation, skewness, kurtosis) of low-dose and standard-dose CT in a group of patients affected by idiopathic interstitial pneumonitis.


METHODS
We analyzed 16 patients affected by idiopathic interstitial pneumonitis. Spiral whole lung thin-section CT acquisition at standard dose (100 mAs) and three additional low-dose (50 mAs) CT images were obtained. After obtained frequency histograms, mean lung attenuation (MLA), skewness and kurtosis and three range of density (-700/-200 HU; -700/-400 HU; -500/-200 HU) of the standard-and low-dose thin-section CT scans were analyzed and compared.


RESULTS
The parameters obtained with low-dose and standard-dose spiral CT were correlated in a highly significant manner and were equivalent (p<0.01). The greatest correlation was found between standard-and low-dose kurtosis and standard and low-dose -700/-400 HU subrange of density (r=0.92; p<0.0001).


CONCLUSIONS
Our results prove that a quantitative CT objective evaluation in lung fibrosis can be successfully obtained with low-dose spiral CT, with reduced mA.
Department of Clinical Sciences, Section of Radiology, University of Parma, Via Rasori, 10 43100 Parma, Italy. nicolasve@tiscali.it
Nicola
N
Sverzellati
Maurizio
M
Zompatori
Giovanni
G
De Luca
Alfredo
A
Chetta
Claudio
C
Bnà
Francesca
F
Ormitti
Rocco
R
Cobelli
D000328:Adult; D005260:Female; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods*