title: The relationship between mediastinal lymph node attenuation with parenchymal lung parameters in silicosis.
abstract: 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.
authors.affiliation: Department of Diagnostic Radiology, University of Hong Kong, Queen Mary Hospital, Hong Kong. cgcooi@hkucc.hku.hk
authors.forename: C G C
authors.initials: CG
authors.lastname: Ooi
authors.forename: P L
authors.initials: PL
authors.lastname: Khong
authors.forename: R S Y
authors.initials: RS
authors.lastname: Cheng
authors.forename: B
authors.initials: B
authors.lastname: Tan
authors.forename: F
authors.initials: F
authors.lastname: Tsang
authors.forename: I
authors.initials: I
authors.lastname: Lee
authors.forename: V S C
authors.initials: VS
authors.lastname: Lam
authors.forename: K K Y
authors.initials: KK
authors.lastname: Leung
authors.forename: K W T
authors.initials: KW
authors.lastname: Tsang
mesh_terms: 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*