Volume adjustment of lung density by computed tomography scans in patients with emphysema
| Autor: | Saher B. Shaker, A. Dirksen, L. C. Laursen, N.‐H. Holstein‐Rathlou, Lene Theil Skovgaard |
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| Rok vydání: | 2004 |
| Předmět: |
Male
Percentile Vital Capacity Respiratory physiology Absorptiometry Photon Forced Expiratory Volume alpha 1-Antitrypsin Deficiency Image Processing Computer-Assisted Medicine Humans Radiology Nuclear Medicine and imaging Lung volumes Lung Aged Radiological and Ultrasound Technology business.industry Respiratory disease Smoking Total Lung Capacity General Medicine respiratory system Middle Aged medicine.disease respiratory tract diseases Airway Obstruction medicine.anatomical_structure Inhalation Pulmonary Emphysema Pulmonary Diffusing Capacity Female Tomography business Nuclear medicine Densitometry Lung Volume Measurements Tomography X-Ray Computed Volume (compression) Follow-Up Studies |
| Zdroj: | Acta radiologica (Stockholm, Sweden : 1987). 45(4) |
| ISSN: | 0284-1851 |
| Popis: | Purpose: To determine how to adjust lung density measurements for the volume of the lung calculated from computed tomography (CT) scans in patients with emphysema. Material and Methods: Fifty patients with emphysema underwent 3 CT scans at 2‐week intervals. The scans were analyzed with a software package that detected the lung in contiguous images and subsequently generated a histogram of the pixel attenuation values. The total lung volume (TLV), lung weight, percentile density (PD), and relative area of emphysema (RA) were calculated from this histogram. RA and PD are commonly applied measures of pulmonary emphysema derived from CT scans. These parameters are markedly influenced by changes in the level of inspiration. The variability of lung density due to within‐subject variation in TLV was explored by plotting TLV against PD and RA. Results: The coefficients for volume adjustment for PD were relatively stable over a wide range from the 10th to the 80th percentile, whereas for RA the coefficients showed large variability especially in the lower range, which is the most relevant for quantitation of pulmonary emphysema. Conclusion: Volume adjustment is mandatory in repeated CT densitometry and is more robust for PD than for RA. Therefore, PD seems more suitable for monitoring the progression of emphysema. |
| Databáze: | OpenAIRE |
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