Radiology
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Purpose To evaluate the sensitivity, specificity, and diagnostic odds ratios of US, CT, and MRI as second-line imaging modalities after initial US for assessing acute appendicitis in children and adults. Materials and Methods A literature search was conducted in Medline and Embase to identify articles that used surgery or histopathologic examination alone or in combination with clinical follow-up or chart review to evaluate the diagnostic accuracy of second-line imaging modalities. The quality of articles was assessed by using the Quality Assessment of Diagnostic Accuracy Studies-2 and the Standards for Reporting of Diagnostic Accuracy tools. ⋯ Regarding second-line MRI in children, pooled sensitivities and specificities were 97.4% (95% CI: 85.8%, 100%) and 97.1% (95% CI: 92.1%, 99.0%); and in adults, the pooled sensitivities and specificities were 89.9% (95% CI: 84.8%, 93.5%) and 93.6% (95% CI: 90.9%, 95.5%), respectively. Conclusion Second-line US, CT, and MRI have comparable and high accuracy in helping to diagnose appendicitis in children and adults, including pregnant women. All three modalities may be valid as second-line imaging in a clinical imaging pathway for diagnosis and management of appendicitis.
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Purpose To follow the evolution of intracranial hemorrhage (ICH) by using quantitative susceptibility mapping (QSM). Materials and Methods Thirty-six patients with ICH confirmed at CT were enrolled to follow ICH evolution on day 2, 7, and 30 after symptom onset between August 2013 and April 2017. QSM was reconstructed from MRI gradient-echo phase images acquired at 1.5 T or 3.0 T. ⋯ The mean CT attenuation and mean susceptibility of ICH were linearly correlated (r2 = 0.29). Excellent intra- and interobserver reproducibility were found for QSM (intraclass correlation coefficient, 0.987 and 0.966, respectively). Conclusion Longitudinal evolution of intracranial hemorrhage (ICH) by using quantitative susceptibility mapping (QSM) demonstrated susceptibility differences in different disease stages, which was not found at conventional MRI; therefore, QSM may assist in quantitatively following ICH iron content.