The relationship between mediastinal lymph node attenuation with parenchymal lung parameters in silicosis.
OBJECTIVE
Attenuation changes on computed tomography (CT) in mediastinal lymph nodes (LN) may be related to lung alterations and functional impairment in silicosis.


METHODS
CT and clinical data of 41 (64.2 +/- 8.3 years) males with silicosis were retrieved. Attenuation type (calcified, hyperdense, normodense) and calcification pattern (central, eccentric, dense, eggshell, speckled) of mediastinal LN were evaluated; LN attenuation of uncalcified LNs quantified on CT in six LN stations. Nodular profusion (CT-NP) and progressive massive fibrosis (CT-PMF) were graded. Relationships between LN, CT, lung function and clinical parameters were determined.


RESULTS
LN sites were paratracheal (n = 39), subcarinal (n = 39), tracheobronchial (n = 37), aortopulmonary (n = 37), hilar (n = 27), and peri-oesophageal (n = 21). LNs were calcified, hyperdense and normodense in 107, 85 and 54 LN stations, respectively. Uniformly calcified LN was most common, followed by speckled calcification. Central, eccentric and eggshell calcification was rare. CT-NP scores > or = 16 were associated with higher LN attenuation and number of calcified LN stations than CT-NP scores < 16. PMF had no influence over LN morphology or calcification pattern. LN attenuation correlated with CT-PMF (r = 0.36, P = 0.01), CT-NP (r = 0.54, P < 0.001) and DLCO/VA (r = -0.33, P = 0.02).


CONCLUSIONS
Uniformly calcified and hyperdense LNs are common in silicosis, and eggshell LN calcification is rare. There are associations between LN attenuation and lung function impairment, and CT grades of nodular profusion and PMF.
Ooi
C G C
CG
Department of Diagnostic Radiology, University of Hong Kong, Queen Mary Hospital, Hong Kong. cgcooi@hkucc.hku.hk
Khong
P L
PL
Cheng
R S Y
RS
Tan
B
B
Tsang
F
F
Lee
I
I
Lam
V S C
VS
Leung
K K Y
KK
Tsang
K W T
KW
D000368:Aged; D001707:Biopsy, Needle; D002114:Calcinosis / Q000473:pathology; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008482:Mediastinum; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging / Q000473:pathology; D011658:Pulmonary Fibrosis / Q000473:pathology*; D012129:Respiratory Function Tests; D018570:Risk Assessment; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012829:Silicosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D018709:Statistics, Nonparametric; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*