Calcium score: semiautomatic calculation using different vendors versus fully automatic software.

OBJECTIVES: Recent advances in technology have resulted in a multitude of cardiac imaging postprocessing software products from vendors unrelated to the scanner on which the cardiac study was initially performed. A fully automatic calcium score software has also become available. We assess the intervendor variability of calcium score measurement using the semiautomatic software provided by the scanner vendor versus an unrelated vendor versus fully automatic software. METHODS: All consecutive patients who had a calcium score performed from March 2007 to January 2008 were included in this study. The studies were performed on two 64-slice computed tomographic scanners from 2 different vendors. The allocation of the patient to the specific scanner was done according to scanner and technologist availability. The studies were read twice by a cardiac radiologist and a general radiologist with at least 3 months' interval at a workstation specified by the computed tomographic scanner vendor and then at an unrelated workstation, with semiautomatic software. Calcium score was also independently performed by the fully automatic software, blinded to the results of previous readings. Agreement was tested with Pearson correlation coefficient, Bland-Altman graphs, and the Fleiss κ test. RESULTS: The study population included 101 patients: 70 patients scanned at 1 scanner and 31 at a different scanner. Intervendor variability for the 2 groups had κ = 0.98 ± 0.01 and κ = 0.96 ± 0.02; interobserver variability had κ = 1. Semiautomatic versus automatic variability showed κ = 0.88 to 0.94. CONCLUSIONS: Because of very strong agreement between the calcium score measurements obtained by semiautomatic and fully automatic software by different vendors, calcium score measurements can be performed robustly at vendor-specific software, nonrelated software, or fully automatic software.

Sonographic detection of pneumothorax by radiology residents as part of extended focused assessment with sonography for trauma.

OBJECTIVE: The purpose of this study was to assess the accuracy of sonographic pneumothorax detection by radiology residents as a part of extended focused assessment with sonography for trauma (eFAST). METHODS: In a prospective study, a sonographic search for pneumothoraces was performed as part of a standard FAST examination by the on-call resident. Each lung field was scanned at the second to fourth anterior intercostal spaces and the sixth to eighth midaxillary line intercostal spaces. A normal pleural interface was identified by the presence of parietal-over-visceral pleural sliding with "comet tail" artifacts behind. Absence of these normal features indicated a pneumothorax. The sonographic diagnosis was correlated with supine chest radiography and chest computed tomography (CT). RESULTS: A total of 338 lung fields in 169 patients were included in the study. Patients underwent eFAST, chest radiography, and chest CT when clinically indicated. Chest CT was considered the reference standard examination. Computed tomography identified 43 pneumothoraces (13%): 34 small and 9 moderate. On chest radiography, 7 pneumothoraces (16%) were identified. Extended FAST identified 23 pneumothoraces (53%). Compared with CT, eFAST had sensitivity of 47%, specificity of 99%, a positive predictive value of 87%, and a negative predictive value of 93%. All of the moderate pneumothoraces were identified by eFAST. Twenty small pneumothoraces missed by eFAST did not require drainage during the hospitalization period. CONCLUSIONS: Extended FAST performed by residents is an accurate and efficient tool for early detection of clinically important pneumothoraces.