Optimization of Perfusion CT Protocol for Imaging of Extracranial Head and Neck Tumors

Optimization of the DCE-CT protocol using active imaging

“…Unless otherwise specified, we will assume in this paper F = 70 ml/min/100g, P S = 17 ml/min/100g, v 1 = 5 ml/100g, v 2 = 20 ml/100g. These values correspond to invivo measurements from extracranial head and neck tumors [8].…”

“…Values of the objective function (arbitrary unit) for the standard protocol, the schedule proposed by Bisdas et al [8], and the solutions found in experiment 3.1 and 3.2 correspond to periods when the measurement is particularly sensitive to different parameters. The first cluster during the initial rise in the signal is sensitive to F ; the second cluster near the peak is sensitive to F , v 1 and P S; the third cluster during the decreasing in the concentration is sensitive to v 1 , P S, v 2 ; the fourth cluster is sensitive to v 2 and P S. A few other measurements are spaced out in between the four clusters.…”

“…This both reduces the radiation dose and increases parameter estimate accuracy and precision. Preliminary work by Bisdas et al [8] uses simulations to demonstrate that exponentially increasing spacing in the second phase improves on the standard fixed spacing. Here we provide a much more general optimization over the whole space of allowable schedules.…”

Perfusion CT in Squamous Cell Carcinoma of the Upper Aerodigestive Tract: Long-Term Predictive Value of Baseline Perfusion CT Measurements

“…16 The elevated PS values in our study are also calculated under certain assumptions of the deconvolution-based software (with adiabatic tissue homogeneity modeling), 17,18 and the 55-second acquisition comprises certain estimation errors. 19 Thus, it seems controversial that high PS, which may be related to genetically highly aggressive tumor cell clusters characterized by increased angiogenic activity, 20 showed a better response to neoadjuvant therapy protocols. Potentially, the increased shunt flow and extravasation in the newly formed vessels may result in increased distribution of chemotherapeutic agents.…”

Dynamic contrast-enhanced CT imaging of hepatocellular carcinoma in cirrhosis: feasibility of a prolonged dual-phase imaging protocol with tracer kinetics modeling

“…The latter option may seem favourable considering radiation dose, but a direct consequence of increasing the interval is the degradation of the sampled arterial and portal venous input curves, which would result in an increase of estimation errors for all parameters involved. Future work could explore these aspects in the design of DCE CT protocols by using Monte Carlo simulations [30], to provide insights on the optimal temporal placement of scans and parameter accuracy trade-offs for DCE CT imaging of liver tumours.…”