title: Assessment of alveolar epithelial permeability in Behçet's disease with 99mTc-DTPA aerosol scintigraphy.
abstract: OBJECTIVE
  Behçet's disease (BD) is a multisystem disorder characterized by vasculitis, and consists of a triad of recurrent ulcers of the oral and genital mucosa with relapsing uveitis. The prevalance of pulmonary involvement varies in the range of 1-10% in various studies and its complications are severe and life threatening. In this study, we investigated the changes of pulmonary epithelial permeability of patients with BD using technetium-99m diethylene triamine penta-acetic acid ((99m)Tc-DTPA) aerosol scintigraphy, so as to begin the therapy regimen as soon as possible.
  
  
  METHODS
  Twenty-one nonsmoking patients with BD (8 women, 13 men; mean age 38.67 +/- 8.86 years) and 15 healthy volunteer nonsmoking controls (8 women, 7 men; mean age 50.87 +/- 12.45 years) underwent (99m)Tc-DTPA aerosol inhalation scintigraphy and pulmonary function tests (PFTs). Subjects inhaled 1480 MBq of (99m)Tc-DTPA for 4 min in the supine position. Scintigraphic data were recorded dynamically (1 frame/min) in the posterior projection on a 64 x 64 matrix for a 30-min period using a double-headed gamma camera (Infinia, GE, Tirat Hacarmel, Israel) equipped with a low-energy all-purpose parallel hole collimator. Half time of (99m)Tc-DTPA clearance (T (1/2)) was calculated by placing a mono-exponential fit on the curves. Penetration index (PI) was also calculated by dividing the peripheral total counts by the sum of the peripheral and central total counts on the first minute image, in order to quantify the distribution of the inhaled aerosol.
  
  
  RESULTS
  The clearance half time of (99m)Tc-DTPA radioaerosols in the BD patients (24.81 +/- 6.22 min) was faster than in the normal control group (46.53 +/- 22.41 min) (P = 0.004). There was also a significant difference between PI of the patients with BD (0.15 +/- 0.03) and that of the controls (0.21 +/- 0.06) (P = 0.002). No correlation was found between the mean T (1/2) values of (99m)Tc-DTPA clearance or the spirometric measurements in the BD patients. Penetration indices were not correlated with PFT in the BD patients.
  
  
  CONCLUSIONS
  Lung epithelial permeability of the patients with BD was significantly higher than that of the normal subjects. The results of this study demonstrated that the assessment of lung epithelial permeability using (99m)Tc-DTPA aerosol scintigraphy could predict the presence of lung involvement in the early stages of BD.
authors.affiliation: Department of Nuclear Medicine, Celal Bayar University School of Medicine, Uncubozkoy Mevkii, 45030 Manisa, Turkey. fggumuser@hotmail.com
authors.forename: Fikriye G
authors.initials: FG
authors.lastname: Gumuser
authors.forename: Timur
authors.initials: T
authors.lastname: Pirildar
authors.forename: Dilek
authors.initials: D
authors.lastname: Batok
authors.forename: Aysin
authors.initials: A
authors.lastname: Sakar
authors.forename: Ebru
authors.initials: E
authors.lastname: Ruksen
authors.forename: Elvan
authors.initials: E
authors.lastname: Sayit
mesh_terms: D000328:Adult; D000336:Aerosols; D001528:Behcet Syndrome / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D010539:Permeability; D011650:Pulmonary Alveoli / Q000000981:diagnostic imaging* / Q000378:metabolism*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D020545:Respiratory Mucosa / Q000000981:diagnostic imaging* / Q000378:metabolism*; D012680:Sensitivity and Specificity; D016284:Technetium Tc 99m Pentetate / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D000336:Aerosols; D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate