title: Assessment of the accuracy of lacrimal scintigraphy based on a prospective analysis of patients' symptomatology.
abstract: BACKGROUND
  Dacryoscintigraphy is a noninvasive method frequently used for assessment of the lacrimal drainage system. Sometimes conflicting results with patients' complaints are obtained, which have no clear explanation. In our hypothesis, follow-up of patients evaluated with dacryoscintigraphy could be helpful in determining possible explanations for these conflicting results.
  
  
  METHODS
  Thirty-eight consecutive patients (76 eyes) who had not previously undergone dacryocystorhinostomy or probing were entered in the study. Following instillation of 4 MBq (99m)Tc-pertechnetate, a routine procedure of dacryoscintigraphy was performed. After a mean follow-up time of 1.2 +/- 0.3 years (range 0.9-1.6 years), all patients were reassessed clinically.
  
  
  RESULTS
  Using initial patients' symptoms as the gold standard, the sensitivity, specificity, NPV, and PPV of dacryoscintigraphy were calculated to be 82.1%, 75%, 60%, and 90.1%, respectively. The kappa value as a measure of agreement was 0.52. Considering the follow-up study as the gold standard, the sensitivity, specificity, NPV, and PPV were calculated as follows, respectively: 96.3%, 90.4%, 96.3%, and 90.4%. The kappa value was 0.86. There were three initially symptom-free eyes with obstructive pattern on the scans, which developed epiphora on the follow-up. In fact, these eyes were initially classified as false positive, but follow-up assessment showed that they were true-positive scans in a subclinical state.
  
  
  CONCLUSIONS
  Despite certain drawbacks inherent to the technique, dacryoscintigraphy provides valuable independent information and allows more accurate management decisions. In some patients, data obtained from lacrimal scintigraphy could be predictive, and it makes possible determination of subclinical nasolacrimal duct obstructions.
authors: Research Institute for Nuclear Medicine, Tehran University of Medical Sciences, Shariati Hospital, Tehran, Iran.
authors: Armaghan
authors: A
authors: Fard-Esfahani
authors: Ali
authors: A
authors: Gholamrezanezhad
authors: Sahar
authors: S
authors: Mirpour
authors: Ali Sadeghi
authors: AS
authors: Tari
authors: Mohsen
authors: M
authors: Saghari
authors: Davood
authors: D
authors: Beiki
authors: Babak Fallahi
authors: BF
authors: Sichani
authors: Mohammad
authors: M
authors: Eftekhari
mesh_terms: D000328:Adult; D000368:Aged; D003608:Dacryocystorhinostomy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007767:Lacrimal Duct Obstruction / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013670:Sodium Pertechnetate Tc 99m
chemical_list: D019275:Radiopharmaceuticals; D013670:Sodium Pertechnetate Tc 99m