| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Pediatric Imaging |
1 From the Depts of Paediatric Pulmonology (P.A.d.J., H.A.W.M.T.) and Paediatric Radiology (M.H.L.), Erasmus Med Ctr Rotterdam, Sophia Children’s Hosp, Dr Molewaterplein 60, 3015 GJ Rotterdam, the Netherlands; Dept of Epidemiology and Biostatistics (W.C.J.H.), Erasmus Med Ctr Rotterdam, the Netherlands; Depts of Paediatric Pulmonology (M.D.O., J.J.E.H.) and Radiology (S.G.F.R.), Univ Hosp Maastricht, the Netherlands; and Univ of British Columbia, McDonald Research Lab and iCAPTURE Ctr, St Paul’s Hosp, Vancouver, Canada (P.D.P.). Received Oct 29, 2002; revision requested Jan 9, 2003; final revision received Sep 10; accepted Sep 29. Address correspondence to H.A.W.M.T. (e-mail: h.tiddens@erasmusmc.nl).
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
MATERIALS AND METHODS: Scores obtained with five thin-section CT scoring systems were compared. A score of 0 indicated the absence of abnormalities; a higher score meant that more structural abnormalities were seen. Three observers assigned scores and then reassigned scores after intervals varying from 1–2 weeks to 1–2 months at review of thin-section CT scans obtained in 25 children with cystic fibrosis. Interobserver and intraobserver reliability was calculated with intraclass correlation coefficients. Quantitative measurements of bronchial and arterial dimensions were obtained. Thin-section CT scores were correlated (Spearman correlation) with bronchial and arterial dimensions and with results of pulmonary function tests (PFTs), such as forced expiratory volume in 1 second (FEV1).
RESULTS: Scores with all five scoring systems were reproducible, with intraclass correlation coefficients of 0.74 and higher (P < .05), and showed significant correlations with FEV1 (R = –0.73 to –0.69, P < .01). Ratio of bronchial diameter to accompanying pulmonary arterial diameter was correlated with thin-section CT scores but not with FEV1. Ratio of bronchial wall thickness to accompanying pulmonary arterial diameter was not correlated with thin-section CT scores or PFT results.
CONCLUSION: Thin-section CT scores were reproducible and were correlated with PFT results. Measurements of bronchial dimensions were not significantly related to scores or PFT results.
© RSNA, 2004
Index terms: Computed tomography (CT), in infants and children, 60.1211, 60.12118 • Computed tomography (CT), thin-section, 60.12118 • Fibrosis, cystic, 60.252 • Lung, CT, 60.1211, 60.12118 • Lung, function
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
In the last decade, the use of thin-section computed tomography (CT) in cystic fibrosis has increased. In 1990, Bhalla et al (8) published a scoring system designed to quantify structural lung abnormalities in patients with cystic fibrosis by using thin-section CT. Since then, a number of additional scoring systems and modifications of scoring systems have been proposed, and they are frequently used for both clinical treatment and research purposes (9). Thin-section CT scoring systems are a potentially useful outcome measure surrogate in patients with cystic fibrosis (10). To date to our knowledge, there is limited experience with the use of these scoring systems for assessment of pulmonary disease in children with cystic fibrosis, and there have been no systematic comparisons of the scoring systems. In addition, the quantitative nature of thin-section CT allows precise measurements of bronchial and arterial dimensions, and these may have added value in the assessment of lung abnormalities in patients with cystic fibrosis.
Thus, the purpose of our study was to retrospectively compare thin-section CT scoring systems of Bhalla et al (8), Helbich et al (11), Santamaria et al (12), Brody et al (10), and Castile et al (13) for assessment of pulmonary disease in children with cystic fibrosis and to determine the additional value of measurements of bronchial and arterial dimensions.
|
MATERIALS AND METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
Thin-Section CT and Evaluation
Thin-section CT scans were obtained (Prospeed SX; GE Medical Systems, Milwaukee, Wis) with the patients in the supine position after they were instructed to take a deep breath and hold their breath for at least 5 seconds. During each breath hold, approximately two lung sections were obtained. A complete thin-section CT series included on average 25 (range, 16–34 sections) 1.0-mm-thick sections that were acquired with 10-mm intervals from the lung apex to the lung base. Scanning parameters were as follows: 120 kV, 160 mA (120 mA in children younger than 9 years), 1-second scanning time, and a field of view of 350 mm (250 mm in children younger than 9 years). Scans were reconstructed with a reconstruction algorithm (Detail; GE Medical Systems) and printed with window settings appropriate for the imaging of pulmonary parenchyma (window width, –600 HU; window level, 1,500 HU).
We selected five thin-section CT scoring systems (8,10–13) for evaluation. These systems can be categorized into two groups: lobar scoring systems (10,13), in which a score is assigned to each lung lobe separately, and segmental scoring systems (8,11,12), in which a score is assigned to each bronchopulmonary segment separately. With all systems, a score is assigned in a semiquantitive way to a subset of the following abnormalities: bronchiectasis; peribronchial thickening; mucus plugging; sacculations or abcesses; bullae; emphysema, air trapping, or hyperinflation; collapse or consolidation; mosaic perfusion or ground-glass opacities; acinar nodules or alveolar consolidation; and thickening of intralobular and interlobular septa. These abnormalities were considered to be the variables and were assigned scores that ranged from 0 to 3. The total scores were derived as composites of the variables that were assigned these scores. The scores assigned to the variables were used in the calculation of the 
statistic. The total scores ranged from 0 (indicating absence of abnormalities) to 92, 100, 27, 29, and 25 (indicating maximal abnormalities) for scoring systems of Castile et al (13), Brody et al (10), Helbich et al (11), Santamaria et al (12), and Bhalla et al (8), respectively. Hereafter, these scores will be referred to as the Castile, Brody, Helbich, Santamaria, and Bhalla scores.
Thin-section CT scans were assigned scores by three observers. Observers 1 and 2 were 5th-year medical students who underwent intensive training in how to score the thin-section CT scans. Observer 3 was a senior radiologist. After the training period, a consensus meeting was held to further standardize the scoring between the three observers. For the scoring methods used in this study, no reference images were available. All 25 scans were assigned scores in random order, and observers assigned scores independently and were blinded to patient characteristics. To evaluate intraobserver variability, random subsets of 10 scans were assigned scores a second time after 1–2 weeks (observer 1), 2–4 weeks (observer 2), and 1–2 months (observers 1 and 3).
Measurements of bronchial dimensions on the CT scans were performed by using a workstation (GE Medical Systems, Milwaukee, Wis) with software (version AW 3.1; GE Medical Systems) that supported the CT scanner used in this study. All visible bronchus-artery pairs that appeared to be round were magnified five times, and two perpendicular lines were traced through the center of each bronchus and the accompanying pulmonary artery. One line was vertical and the other was horizontal to the plane of gravity. The software program constructed a profile of the Hounsfield units along the lines, and the observer calculated the cutoff level for the inner and the outer wall according to the full-width-at-half-maximum principle (14).
Since bronchial diameter and bronchial wall thickness change as a function of airway generation, we calculated ratios of bronchial and arterial dimensions rather than absolute values. One of the ratios was calculated by dividing the mean outer bronchial diameter by the mean diameter of the accompanying pulmonary artery, and this was the bronchus-artery ratio. This ratio has previously been reported as an indicator of bronchial dilatation or bronchiectasis (8). In the case of bronchiectasis, the simple measurement of bronchial wall thickness divided by bronchial luminal diameter could cause spurious underestimation of intrinsic bronchial wall thickening. Thus, to obtain an estimate of bronchial wall thickness, we used the ratio of the mean bronchial wall thickness divided by the mean diameter of the accompanying pulmonary artery, and this was the thickness-artery ratio. This calculation was determined with the assumption that there is no change in arterial diameter as pulmonary disease progresses in cystic fibrosis. On average, an observer assigned scores on each scan in 10 minutes for the lobular systems (10,13) and in 15 minutes for the bronchopulmonary systems (8,11,12).
PFT Results
The PFT results used for this study were obtained with PFTs performed most closely in time to the time that the thin-section CT scans were obtained. Twenty children were evaluated with PFTs and thin-section CT on the same day. For three children, thin-section CT was performed on a different day from that on which the PFTs were performed for logistic reasons (intervals between CT and PFTs were 5, 12, and 23 days).
PFT results were obtained by using a diagnostic system (MasterLab; Jäger, Wurzburg, Germany). The results were expressed as the percentage of predicted values for forced expiratory volume in 1 second (FEV1) (15), forced vital capacity (FVC) (15), and forced expiratory flow between 25% and 75% of expiratory vital capacity (FEF25%–75%) (16). The ratio of FEV1 to FVC was calculated and expressed as a percentage. Additional measurements included airway resistance (Raw), residual volume (RV), and total lung capacity (TLC). Values for these measurements were obtained by using a body plethysmograph. The RV/TLC ratio was calculated and expressed as a percentage.
Statistical Analysis
Interobserver and intraobserver reliability of the scoring systems was tested with the intraclass correlation coefficient (Ri) and Bland-Altman plots. Values of Ri greater than 0.80 are generally considered to represent good agreement between observers. Interobserver and intraobserver reliability of the various scoring system variables of each of the five scoring systems was evaluated with the statistic. The values of <0.20, 0.21–0.40, 0.41–0.60, 0.61–0.80, and 0.81–1.00 are generally considered to represent poor, fair, moderate, good, and very good agreement, respectively. The mean and individual scores of three observers were used to calculate the Spearman correlation, or R, between the scoring systems and that between the scoring systems and PFT results. Furthermore, the Spearman correlation was calculated for the quantitative thin-section CT measurements (thickness-artery and bronchus-artery ratios) with mean thin-section CT scores and with PFT results. Normal distribution of all ratios (thickness-artery, bronchus-artery, FEV1/FVC, and RV/TLC) was tested by using the Shapiro-Wilk test. A software package (SPSS, version 10.0; SPSS, Chicago, Ill) was used for statistical analysis. Data were expressed as the mean ± SD and range. A difference with a P value less than .05 was considered significant.
|
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
|
|
coefficients were less than 0.61 for most scoring system variables. For mosaic perfusion, acinar nodules, and airspace disease, coefficients were less than 0.40 for all comparisons.
|
coefficients were greater than 0.61. Thin-section CT scoring and PFT results.—All five scoring systems showed a strong and highly significant correlation with values for FEV1, FVC, FEF25%–75%, and FEV1/FVC ratio (Table 4). The relationship between Bhalla score and FEV1 is shown in Figure 1. The correlation coefficients were highest for the relationships between thin-section CT scores and the FEF25%–75% value and lowest for the relationships with the FVC value; R values for the relationships between scores and values for FEV1 and FEV1/FVC ratio were intermediate. Raw and TLC values were correlated significantly with scores achieved with all scoring systems. Values for RV and RV/TLC ratio did not show significant relationships (Table 4). The correlation coefficients did not differ substantially when individual scores from the three observers were used rather than mean scores. The correlation between the scoring systems was strong; R values ranged from 0.94 to 0.99. There was no significant correlation between mean scores and bronchial wall thickness, expressed as the thickness-artery ratio. The marker for the estimate of the severity of bronchiectasis (bronchus-artery ratio) was correlated significantly with scores achieved with all five scoring systems. The R values were as follows: Castile score, 0.59; Brody score, 0.60; Helbich score, 0.50; Santamaria score, 0.51; and Bhalla score, 0.50. Neither the thickness-artery ratio nor the bronchus-artery ratio showed a significant correlation with PFT results, although the relationship between the bronchus-artery ratio and values for FEV1 and FEV1/FVC ratio approached significance (P = .07). All ratios, except the thickness-artery ratio, could be described with normal distributions. We used the Spearman correlation coefficient, which is adequate for nonnormal distributions.
|
|
|
DISCUSSION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
|
First, our data showed a lower reproducibility with longer intervals (1–2 months) between repeat measurements. In part, this finding may be related to the fact that there were gaps between the scoring sessions during which the observers were not routinely scoring CT scans. These gaps might have caused some loss of recall of the scoring systems, as well as of the findings of the consensus meeting. This result suggests that a new training period for observers may be needed after a 1–2-month interval. In addition, it might be useful to develop standardized definitions and reference images to reduce intraobserver and interobserver variability even further.
Second, our results showed a lower interobserver reproducibility for most scoring system variables than for the total score. Many variables had a low coefficient, even after the consensus meeting. An example of one such variable is mosaic perfusion. When we examined the thin-section CT scans closely, almost all scans had some signs of mosaic perfusion, and there was no description of how other authors defined this abnormality. Although all scoring systems except that of Castile et al (13) were designed for inspiratory thin-section CT scans, some investigators designated a low-attenuation area as "hyperinflation" and others identified such an area as "gas trapping." The prevalence of air trapping reported in this study is lower than that previously reported (10–12,17). In the routine follow-up of our patients, we restricted ourselves to the use of inspiratory thin-section CT scans, which are less sensitive in the depiction of air trapping relative to expiratory thin-section CT scans. Currently, we measure air trapping in children who are 6 years old and older by using the combination of helium spirometry and body plethysmography. It is unclear whether it is worthwhile to add more radiation to our standard clinical CT protocol to obtain expiratory CT scans on which air trapping could be scored more reliably. Because of the large variability in nomenclature, we believe that a uniform nomenclature and clear definitions of abnormalities must be developed for use in thin-section CT scoring systems to obtain objective and reproducible thin-section CT data for follow-up of patients and for clinical trials.
The third concern is the increased variability between observers that was evident when the scores were low. If these systems are to be useful in the early detection and longitudinal assessment of lung abnormalities in cystic fibrosis, they should have sufficient resolution of the lower end of the scoring system scale.
An additional way to quantify structural lung damage is with the measurement of bronchial dimensions on thin-section CT scans. We measured the size of the bronchi relative to the accompanying artery (bronchus-artery ratio) and the thickness of the bronchial wall relative to the accompanying artery (thickness-artery ratio). The bronchus-artery ratio, which is a well-recognized measure of bronchiectasis (8), was correlated significantly with thin-section CT scores, presumably because a subjective assessment of bronchial dilatation is an important component of all the scoring systems. However, bronchial wall thickness was not correlated significantly with thin-section CT scores. None of these measurements was correlated significantly with PFT results, although the relationship between the bronchus-artery ratio and values for FEV1 and FEV1/FVC ratio approached significance. These data suggest that, with the technology and algorithms we employed, quantitative bronchial measurements did not add value to the scoring systems. Further research is necessary to determine the role of bronchial measurements and their correlation with disease severity, as well as their interobserver and intraobserver variability.
It has been shown that thin-section CT scans are superior to chest radiographs to monitor structural aspects of pulmonary disease in cystic fibrosis (18). Radiation dose is of concern, however, since life expectancy is increasing in patients with cystic fibrosis (19). The radiation dose of the thin-section CT protocol we used is approximately 12 times that of a chest radiograph (20). Although this dose is not as high as has been suggested by some authors (21), one needs to exercise caution. Because of concern regarding the balance between radiation and benefits from the additional information about lung structure, clinical centers for cystic fibrosis are performing biennial rather than annual thin-section CT examinations. New ways to further reduce the dose of radiation at thin-section CT must be found, and optimal scanning parameters for the pediatric age group have to be determined (19). Researchers in several studies have already shown that low-dose thin-section CT, with a 40%–50% reduction of radiation dose, is possible without affecting image quality (22–25).
To conclude, the results of this study show that adequate thin-section CT scans can be obtained in young children who have cystic fibrosis. Structural abnormalities observed on thin-section CT scans can be assigned scores in a reproducible fashion with currently available scoring systems. These findings support the use of thin-section CT to monitor progression of structural lung abnormalities in cystic fibrosis. Such use can be important for both patient treatment and therapeutic studies.
|
FOOTNOTES |
|---|
Abbreviations: FEF25%–75% = forced expiratory flow between 25% and 75% of expiratory vital capacity, FEV1 = forced expiratory volume in 1 second, FVC = forced vital capacity, PFT = pulmonary function test, Raw = airway resistance, RV = residual volume, TLC = total lung capacity
Author contributions: Guarantors of integrity of entire study, P.A.d.J., H.A.W.M.T.; study concepts and design, P.A.d.J., M.H.L., S.G.F.R., W.C.J.H., H.A.W.M.T.; literature research, P.A.d.J., H.A.W.M.T.; clinical studies, H.A.W.M.T., S.G.F.R., M.H.L.; data acquisition, P.A.d.J., M.D.O., S.G.F.R.; data analysis/interpretation, P.A.d.J., M.D.O., J.J.E.H., S.G.F.R., H.A.W.M.T., W.C.J.H., P.D.P.; statistical analysis, P.A.d.J., M.D.O., H.A.W.M.T., W.C.J.H.; manuscript preparation, P.A.d.J., M.D.O., J.J.E.H., H.A.W.M.T.; manuscript definition of intellectual content, P.D.P., H.A.W.M.T., P.A.d.J.; manuscript editing, H.A.W.M.T., J.J.E.H., P.A.d.J., P.D.P., M.H.L., S.G.F.R., M.D.O.; manuscript revision/review and final version approval, all authors
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
This article has been cited by other articles:
|
|
 |
|
  F. Santamaria, S. Montella, H. A. W. M. Tiddens, G. Guidi, V. Casotti, M. Maglione, and P. A. de Jong Structural and Functional Lung Disease in Primary Ciliary Dyskinesia Chest, August 1, 2008; 134(2): 351 - 357. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P M Gustafsson, P A De Jong, H A W M Tiddens, and A Lindblad Multiple-breath inert gas washout and spirometry versus structural lung disease in cystic fibrosis Thorax, February 1, 2008; 63(2): 129 - 134. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Donadieu, C. Roudier, M. Saguintaah, C. Maccia, and R. Chiron Estimation of the Radiation Dose From Thoracic CT Scans in a Cystic Fibrosis Population Chest, October 1, 2007; 132(4): 1233 - 1238. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. E. Robinson Computed Tomography Scanning Techniques for the Evaluation of Cystic Fibrosis Lung Disease Proceedings of the ATS, August 1, 2007; 4(4): 310 - 315. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. A. de Jong and H. A. W. M. Tiddens Cystic Fibrosis Specific Computed Tomography Scoring Proceedings of the ATS, August 1, 2007; 4(4): 338 - 342. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. A. W. M. Tiddens and P. A. de Jong Imaging and Clinical Trials in Cystic Fibrosis Proceedings of the ATS, August 1, 2007; 4(4): 343 - 346. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. A. Aziz United Kingdom Cystic Fibrosis Gene Therapy Consortium Multidose Trial: The Proposed Use of Computed Tomography Proceedings of the ATS, August 1, 2007; 4(4): 355 - 358. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. W. Ramsey Use of Lung Imaging Studies as Outcome Measures for Development of New Therapies in Cystic Fibrosis Proceedings of the ATS, August 1, 2007; 4(4): 359 - 363. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. W. Ramsey Outcome Measures for Development of New Therapies in Cystic Fibrosis: Are We Making Progress and What Are the Next Steps? Proceedings of the ATS, August 1, 2007; 4(4): 367 - 369. [Full Text] [PDF]
|
|
|
|
|
|
S. D. Davis, A. S. Brody, M. J. Emond, L. C. Brumback, and M. Rosenfeld Endpoints for Clinical Trials in Young Children with Cystic Fibrosis Proceedings of the ATS, August 1, 2007; 4(4): 418 - 430. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. P. Schuster The Opportunities and Challenges of Developing Imaging Biomarkers to Study Lung Function and Disease Am. J. Respir. Crit. Care Med., August 1, 2007; 176(3): 224 - 230. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. D. Davis, L. A. Fordham, A. S. Brody, T. L. Noah, G. Z. Retsch-Bogart, B. F. Qaqish, B. C. Yankaskas, R. C. Johnson, and M. W. Leigh Computed Tomography Reflects Lower Airway Inflammation and Tracks Changes in Early Cystic Fibrosis Am. J. Respir. Crit. Care Med., May 1, 2007; 175(9): 943 - 950. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z A Aziz, J C Davies, E W Alton, A U Wells, D M Geddes, and D M Hansell Computed tomography and cystic fibrosis: promises and problems Thorax, February 1, 2007; 62(2): 181 - 186. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Montaudon, P. Berger, A. Cangini-Sacher, G. de Dietrich, J. M. Tunon-de-Lara, R. Marthan, and F. Laurent Bronchial Measurement with Three-dimensional Quantitative Thin-Section CT in Patients with Cystic Fibrosis Radiology, December 19, 2006; (2006) 2422060030. [Abstract] [Full Text]
|
|
|
|
|
|
E. P. Judge, J. D. Dodd, J. B. Masterson, and C. G. Gallagher Pulmonary Abnormalities on High-Resolution CT Demonstrate More Rapid Decline Than FEV1 in Adults With Cystic Fibrosis. Chest, November 1, 2006; 130(5): 1424 - 1432. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. M. Aukland, T. Halvorsen, K. R. Fosse, A. K. Daltveit, and K. Rosendahl High-Resolution CT of the Chest in Children and Young Adults Who Were Born Prematurely: Findings in a Population-Based Study Am. J. Roentgenol., October 1, 2006; 187(4): 1012 - 1018. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P A de Jong, J D Dodd, H O Coxson, C Storness-Bliss, P D Pare, J R Mayo, and R D Levy Bronchiolitis obliterans following lung transplantation: early detection using computed tomographic scanning Thorax, September 1, 2006; 61(9): 799 - 804. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. D. Dodd, S. C. Barry, R. B. M. Barry, C. G. Gallagher, S. J. Skehan, and J. B. Masterson Thin-Section CT in Patients with Cystic Fibrosis: Correlation with Peak Exercise Capacity and Body Mass Index. Radiology, July 1, 2006; 240(1): 236 - 245. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S Jimenez, J R Jimenez, M Crespo, E Santamarta, C Bousono, and J Rodriguez Computed tomography in children with cystic fibrosis: a new way to reduce radiation dose Arch. Dis. Child., May 1, 2006; 91(5): 388 - 390. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. A. de Jong, F. R. Long, J. C. Wong, P. J. Merkus, H. A. Tiddens, J. C. Hogg, and H. O. Coxson Computed tomographic estimation of lung dimensions throughout the growth period Eur. Respir. J., February 1, 2006; 27(2): 261 - 267. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. A. de Jong, J. R. Mayo, K. Golmohammadi, Y. Nakano, M. H. Lequin, H. A. W. M. Tiddens, J. Aldrich, H. O. Coxson, and D. D. Sin Estimation of Cancer Mortality Associated with Repetitive Computed Tomography Scanning Am. J. Respir. Crit. Care Med., January 15, 2006; 173(2): 199 - 203. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P A de Jong, A Lindblad, L Rubin, W C J Hop, J C de Jongste, M Brink, and H A W M Tiddens Progression of lung disease on computed tomography and pulmonary function tests in children and adults with cystic fibrosis Thorax, January 1, 2006; 61(1): 80 - 85. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. S. Brody, H. A. W. M. Tiddens, R. G. Castile, H. O. Coxson, P. A. de Jong, J. Goldin, W. Huda, F. R. Long, M. McNitt-Gray, M. Rock, et al. Computed Tomography in the Evaluation of Cystic Fibrosis Lung Disease Am. J. Respir. Crit. Care Med., November 15, 2005; 172(10): 1246 - 1252. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. M. Martinez, C. J. Llapur, T. H. Williams, C. Coates, R. Gunderman, M. D. Cohen, M. S. Howenstine, O. Saba, H. O. Coxson, and R. S. Tepper High-Resolution Computed Tomography Imaging of Airway Disease in Infants with Cystic Fibrosis Am. J. Respir. Crit. Care Med., November 1, 2005; 172(9): 1133 - 1138. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. E. Robinson, M. L. Goris, H. J. Zhu, X. Chen, P. Bhise, F. Sheikh, and R. B. Moss Dornase Alfa Reduces Air Trapping in Children With Mild Cystic Fibrosis Lung Disease: A Quantitative Analysis Chest, October 1, 2005; 128(4): 2327 - 2335. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. A. de Jong, Y. Nakano, W. C. Hop, F. R. Long, H. O. Coxson, P. D. Pare, and H. A. Tiddens Changes in Airway Dimensions on Computed Tomography Scans of Children with Cystic Fibrosis Am. J. Respir. Crit. Care Med., July 15, 2005; 172(2): 218 - 224. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. A. de Jong, N. L. Muller, P. D. Pare, and H. O. Coxson Computed tomographic imaging of the airways: relationship to structure and function Eur. Respir. J., July 1, 2005; 26(1): 140 - 152. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
U G Rossi and C M Owens The radiology of chronic lung disease in children Arch. Dis. Child., June 1, 2005; 90(6): 601 - 607. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
