Comparison of computed density and macroscopic morphometry in pulmonary emphysema.
High-resolution computed tomography (HRCT) scans were obtained at 1 cm intervals in 63 subjects referred for surgical resection of a cancer or for transplantation to find out whether the relative area of lung occupied by attenuation values lower than a threshold would be a measurement of macroscopic emphysema. Using a semiautomatic procedure, the relative areas occupied by attenuation values lower than eight thresholds ranging from -900 to -970 HU were calculated on the set of scans obtained through the lobe or the lung to be resected. The extent of emphysema was quantified by a computer-assisted method on horizontal paper-mounted lung sections obtained every 1 to 2 cm. The only level for which no statistically significant difference was found between the HRCT and the morphometric data was -950 HU. To determine the number of scans sufficient for an accurate quantification, we recalculated the relative area occupied by attenuation values lower than -950 HU on progressively fewer numbers of scans and investigated the departure from the results obtained with 1 cm intervals. Because of wide variations in this departure from patient to patient, a standard cannot be recommended as the optimal distance between scans.
Gevenois
P A
PA
Department of Radiology, Hôpital Erasme, Brussels, Belgium.
de Maertelaer
V
V
De Vuyst
P
P
Zanen
J
J
Yernault
J C
JC
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008175:Lung Neoplasms / Q000601:surgery; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D010363:Pattern Recognition, Automated; D011013:Pneumonectomy; D011446:Prospective Studies; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D011856:Radiographic Image Enhancement / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*