Premium
Photon‐counting CT for simultaneous imaging of multiple contrast agents in the abdomen: An in vivo study
Author(s) -
Symons Rolf,
Krauss Bernhard,
Sahbaee Pooyan,
Cork Tyler E.,
Lakshmanan Manu N.,
Bluemke David A.,
Pourmorteza Amir
Publication year - 2017
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1002/mp.12301
Subject(s) - renal cortex , gadolinium , contrast (vision) , in vivo , nuclear medicine , iopamidol , renal pelvis , photon counting , imaging phantom , iodinated contrast , iodine , medicine , renal medulla , radiology , materials science , kidney , chemistry , biomedical engineering , contrast medium , computed tomography , detector , physics , microbiology and biotechnology , optics , metallurgy , biology
Purpose To demonstrate the feasibility of spectral imaging using photon‐counting detector (PCD) x‐ray computed tomography (CT) for simultaneous material decomposition of three contrast agents in vivo in a large animal model. Methods This Institutional Animal Care and Use Committee‐approved study used a canine model. Bismuth subsalicylate was administered orally 24–72 h before imaging. PCD CT was performed during intravenous administration of 40–60 ml gadoterate meglumine; 3.5 min later, iopamidol 370 was injected intravenously. Renal PCD CT images were acquired every 2 s for 5–6 min to capture the wash‐in and wash‐out kinetics of the contrast agents. Least mean squares linear material decomposition was used to calculate the concentrations of contrast agents in the aorta, renal cortex, renal medulla and renal pelvis. Results Using reference vials with known concentrations of materials, we computed molar concentrations of the various contrast agents during each phase of CT scanning. Material concentration maps allowed simultaneous quantification of both arterial and delayed renal enhancement in a single CT acquisition. The accuracy of the material decomposition algorithm in a test phantom was −0.4 ± 2.2 mM, 0.3 ± 2.2 mM for iodine and gadolinium solutions, respectively. Peak contrast concentration of gadolinium and iodine in the aorta, renal cortex, and renal medulla were observed 16, 24, and 60 s after the start each injection, respectively. Conclusion Photon‐counting spectral CT allowed simultaneous material decomposition of multiple contrast agents in vivo . Besides defining contrast agent concentrations, tissue enhancement at multiple phases was observed in a single CT acquisition, potentially obviating the need for multiphase CT scans and thus reducing radiation dose.