RATIONALE AND OBJECTIVES: The goal was to improve informativeness in the determination of liver perfusion with a clinically available iodinated computed tomography (CT) contrast agent by developing open multicompartmental modeling. MATERIALS AND METHODS: Contrast-enhanced functional CT (fCT) examinations were conducted with temporal resolutions of 200-500 msec to 6 New Zealand White rabbits. First, we applied conventional open two-compartment model for the determination of arterial and portal blood flows (FA and FP), blood and interstitial volume fractions (fb and fi), and capillary permeability-surface area product (PS) of liver parenchyma. Then, we improved the modeling of vascular physiology by developing three- and open four-compartment models. For comparison, conventional single-compartment model was applied. We determined FA and FP also by using the peak-gradient method. RESULTS: Conventional two-compartment model yielded identical fittings with single-compartment model and does not provide unique solutions for fb and fi. The presented open four-compartment model provided FA and FP values of 0.40 +/- 0.19 and 1.99 +/- 0.57 mL/min/mL (tissue), fb and fi values of 0.30 +/- 0.05 and 0.19 +/- 0.04 mL/mL (tissue), and PS values of 4.0 +/- 1.7 mL/min/mL (tissue). FA and FP are in a good agreement with those derived by using the peak-gradient method. CONCLUSIONS: With the use of clinical extracellular iodinated CT contrast agent, the presented open four-compartment model provided physiological arterial and portal blood flow values and is also a potential tool in the assessment of blood and interstitial volume fractions and capillary permeability-surface area product. Moreover, the model requires neither measurements from hepatic vein or from other organs nor visual determination of arterial or portal phase.
RATIONALE AND OBJECTIVES: The goal was to improve informativeness in the determination of liver perfusion with a clinically available iodinated computed tomography (CT) contrast agent by developing open multicompartmental modeling. MATERIALS AND METHODS: Contrast-enhanced functional CT (fCT) examinations were conducted with temporal resolutions of 200-500 msec to 6 New Zealand White rabbits. First, we applied conventional open two-compartment model for the determination of arterial and portal blood flows (FA and FP), blood and interstitial volume fractions (fb and fi), and capillary permeability-surface area product (PS) of liver parenchyma. Then, we improved the modeling of vascular physiology by developing three- and open four-compartment models. For comparison, conventional single-compartment model was applied. We determined FA and FP also by using the peak-gradient method. RESULTS: Conventional two-compartment model yielded identical fittings with single-compartment model and does not provide unique solutions for fb and fi. The presented open four-compartment model provided FA and FP values of 0.40 +/- 0.19 and 1.99 +/- 0.57 mL/min/mL (tissue), fb and fi values of 0.30 +/- 0.05 and 0.19 +/- 0.04 mL/mL (tissue), and PS values of 4.0 +/- 1.7 mL/min/mL (tissue). FA and FP are in a good agreement with those derived by using the peak-gradient method. CONCLUSIONS: With the use of clinical extracellular iodinated CT contrast agent, the presented open four-compartment model provided physiological arterial and portal blood flow values and is also a potential tool in the assessment of blood and interstitial volume fractions and capillary permeability-surface area product. Moreover, the model requires neither measurements from hepatic vein or from other organs nor visual determination of arterial or portal phase.
Authors: Johnathan C Chung; Dingxin Wang; Robert J Lewandowski; Richard Tang; Howard B Chrisman; Robert L Vogelzang; Gayle E Woloschak; Andrew C Larson; Reed A Omary; Robert K Ryu Journal: J Magn Reson Imaging Date: 2010-05 Impact factor: 4.813
Authors: Dingxin Wang; Sumeet Virmani; Richard Tang; Barbara Szolc-Kowalska; Gayle Woloschak; Reed A Omary; Andrew C Larson Journal: Magn Reson Med Date: 2008-10 Impact factor: 4.668
Authors: Michael Winterdahl; Michael Sørensen; Susanne Keiding; Frank V Mortensen; Aage K O Alstrup; Søren B Hansen; Ole L Munk Journal: Invest Radiol Date: 2012-10 Impact factor: 6.016