ABSTRACT
Objective To evaluate the extent and anatomic distribution of air trapping in lung in young asymptomatic female subjects to achieve early diagnosis of small airway diseases.Methods Fifty young females with normal pulmonary function were included retrospectively in this study.All subjects underwent both inspiratory and expiratory CT scans,the percentage of the area of air trapping(AT)and the percentage of the area of emphysema(Emph)were quantitatively analyzed.Comparison between bilateral lungs was analyzed using independent-samples t test;Comparisons among lobes were done using one-way ANOVA or Kruskal-Wallis rank sum test;Pairwise comparisons between lobes were conducted using LSD test or paired comparison;The effects of each lobe on AT were analyzed using Spearman's rank correlation coefficient,simple linear regression and multiple stepwise regression.Results There was a certain degree of air trapping in lung and a small amount of emphysema in young asymptomatic females.Air trapping was mainly located in the right middle lobe (RML)and bilateral upper lobes.The ratio of air trapping to volume was the highest in RML and the change of air trapping in the bilateral upper lobes had the greatest influence on the air trapping degree of the whole lung.Conclusion There is a certain degree of air trapping in lung in young asymptomatic females.The occurrence and development of air trapping in RML may be a sensitive biomarker for the early detection of pathophysiological changes in small airway diseases using imaging procedures.
ABSTRACT
<p><b>BACKGROUND</b>Magnetic resonance imaging (MRI) has advantages in showing pathologic changes of disc space infection, which is important in clinical treatment. The purpose of this study was to describe the MRI findings of disc space infections in relation to chronicity.</p><p><b>METHODS</b>MRI of 60 patients from January 1, 2002 to April 30, 2012 in Ottawa Hospital were retrospectively evaluated by two radiologists blindly. All patients had histological confirmation, with 55 having microbiological confirmation as well. These patients were divided into acute (n = 18), subacute (n = 21) and chronic (n = 21) based on histological findings. The following potential signs of MRI finding were assessed: marrow edema, endplate erosions, disk fluid and height change, paraspinal mass, epidural collection, facet fluid and enhancement in the marrow, disc, paraspinal mass, and epidural involvement. Statistical analysis consisted of t- or F-tests and chi-square test.</p><p><b>RESULTS</b>In the 60 patients, 83 infected discs (single disc in 45 patients, 2-4 discs in 15 patients) were found, including 22 discs in the acute group, 30 discs in the subacute group, and 31 discs in the chronic group. There was a significant difference in the extent of marrow edema between the acute, subacute and chronic groups (P < 0.05), with a gradually increasing extent from acute to chronic. The extent of endplate erosions increased with chronicity, but was not statistically significant. There were significant differences in the disc fluid, epidural collection, and disc enhancement among the acute, subacute and chronic groups, as well as the facet fluid between acute and chronic groups (P < 0.05). There were no significant differences in the present probability of disc height loss, paraspinal mass, and marrow enhancement among the three groups (P > 0.05).</p><p><b>CONCLUSIONS</b>From acute to chronic infections, the extent of marrow edema and endplate erosions appeared to gradually increase. Epidural collections and facet fluid are most frequently found in the acute group, while disc fluid and disc enhancement are more common in the chronic patients.</p>