Best Protocol for Combined Contrast-Enhanced Thoracic and Abdominal CT for Lung Cancer: A Single-Institution Randomized Crossover Clinical Trial

OBJECTIVE. The purpose of this study was to evaluate the superiority of either of two protocols for combined contrast-enhanced thoracic and abdominal CT of patients with lung cancer by comparing contrast enhancement, contrast-related artifacts, image quality, and radiation dose. SUBJECTS AND METHODS. In this randomized controlled crossover clinical trial, 77 patients who underwent 203 CT examinations were enrolled. All patients underwent at least two examinations performed with both protocols. Protocol A consisted of two acquisitions: one 35-second delayed CT acquisition for the chest followed by a 70-second delayed abdominal acquisition. Protocol B was a single 60-second delayed acquisition covering the chest and the abdomen. Attenuation and noise of the aorta, pulmonary artery, and liver were measured. Contrast-related artifacts, mediastinal lymph node visualization, liver enhancement, and noise were visually scored. Dose-length product was recorded. Statistical analysis was performed by t and chi-squar...