Reduced Contrast Volume and Radiation Dose During Computed Tomography of the Pancreas: Timing-Specific Contrast Media Protocol

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To investigate the opacification of the pancreatic vasculature and parenchyma during computed tomography utilizing a patient-specific contrast formula. This hybrid prospective and retrospective study was approved by the institution review board. In 220 consecutive patients, pancreatic CT was performed with one of two protocols: protocol A, 100mL of contrast material injected via timed bolus triggering technique; or protocol B, employing a patient-specific contrast media protocol specifically timed at the gastroduodenal artery; both protocols employed 4.5 mL/s contrast media and 100mL saline chaser. Attenuation of pancreatic parenchymal, arterial, and venous vasculature supplying the pancreas was measured. Effective dose was calculated. Data were compared to the independent two-sample t test. Receiver operating characteristic, visual grading characteristic, and Cohens' kappa analyses were performed. Mean pancreatic density measurements in each of the pancreatic segments during the arterial and venous phase were significantly higher in Protocol B (mean ± standard deviation, art: 96.59 HU ± 27.37; venous: 91.28 HU ± 20.88) compared to A (art: 77.86 HU ± 21.14; venous: 73.99 HU ± 14.75) (p < 0.0001). Mean arterial opacification was significantly higher in protocol B compared to A with the abdominal aorta (p < 0.007), superior mesenteric (p < 0.0002), gastroduodenal (proximal segment only p < 0.014), and splenic arteries (p < 0.036). In the venous circulation, the inferior vena cava, superior mesenteric, portal and splenic veins (all segments) demonstrated significant reduction in vascular opacification protocol B compared to A (p < 0.001). The contrast media volume in protocol B (57.60 ± 12.25 mL) was significantly lower than in protocol A (100 ± 1 mL) (p < 0.001). Effective dose was significantly reduced in protocol B (2.75 ± 0.63 mSv) compared to A (4.015 ± 0.89 mSv) (p < 0.001). Receiver operating characteristic and visual grading characteristic analysis demonstrated significantly higher area under the curve for protocol B (p < 0.0001) (p < 0.034) respectively, with inter-reader agreement increasing from good to excellent in pancreatic lesion detection. Timing-specific contrast media protocol enhances image quality at reduced contrast volume and radiation dose during computed tomography of the pancreas.