Interobserver variability and accuracy of computed tomographic assessment of nodal status in lung cancer.

To assess the interobserver variability of computed tomography in determining nodal status in non-small cell lung carcinoma, four experienced radiologists reviewed the computed tomographic scans of 147 patients. Interobserver variability was calculated using the kappa statistic. In addition, the accuracy of CT assessment of the nodal status by the four observers was measured by comparing their findings with thorough mediastinal exploration at both mediastinoscopy (n = 35) and thoracotomy (n = 112). Interobserver variability was large between the four radiologists regarding nodal status on a per-patient basis (kappa = 0.38). Sensitivity of computed tomography for the observers on a per-patient basis ranged from 40% to 69% with a 1.0-cm criterion and from 28% to 56% with a 1.5-cm criterion. From the large interobserver variability and the low sensitivities in this study it can be concluded that a negative result of computed tomography regarding mediastinal lymph nodes does not eliminate the need for mediastinoscopy or exploration of the mediastinum at the time of operation in patients with non-small cell lung cancer.

Identifying cytologic characteristics and grading endocervical columnar cell abnormalities. A study aided by high-definition television.

OBJECTIVE: To test the ability of cytotechnologists to recognize and accurately interpret selected architectural, cellular and nuclear features presented on a high-definition television (HDTV) and to make a reliable diagnosis with HDTV. STUDY DESIGN: A total of 1,122 features considered diagnostic of different endocervical columnar cell abnormalities were selected from 50 smears from 48 women with the help of a motor-driven-stage microscope by five observers who had knowledge of the final diagnosis. The selected and stored features were presented on an HDTV and evaluated in five successive sessions without knowledge of the final diagnosis. RESULTS: Specific types of features were correctly identified in a high number of cases. Considerable interobserver variability was demonstrated in the scoring of grades of expression of features. Overrated and under-rated monitor diagnoses were related to overvalued and undervalued features. From a group of 437 images that were correctly diagnosed by four or five observers, five features proved to be highly related to the correct diagnosis. CONCLUSION: Observers were capable of making a reliable diagnosis on features, selected by other observers, when presented on an HDTV. An overall correct diagnosis was made in 93% of cases.