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

Abstract

Dynamic contrast-enhanced (DCE) CT imaging of four patients with hepatocellular carcinoma (HCC) was performed using a dual-phase imaging protocol designed with initial rapid dynamic imaging to capture the initial increase in contrast medium enhancement in order to assess perfusion, followed by a delayed imaging phase with progressively longer intervals to monitor subsequent tissue enhancement behaviour in order to assess tissue permeability. The DCE CT images were analysed using a dual-input two-compartment distributed parameter model to yield separate estimates for blood flow and permeability, as well as fractional intravascular and extravascular volumes. The HCCs and surrounding cirrhotic liver tissues were found to exhibit enhancement curves that can be appropriately described by two distinct compartments separated by a semipermeable barrier. Early contrast arrival was also found for HCC as compared with background liver. These findings are consistent with the current understanding of sinusoidal capillarization and hepatocarcinogenesis.

Functional imaging techniques in hepatocellular carcinoma

“…Arterial blood flow was high with a sensitivity and specificity of detection of 86% and 65% within 11 weeks of tumour induction even though only 7% was visible by eye [38]. A small number of singlecentre human studies have shown the feasibility of DCE CT in HCC for detection and vascular response assessment [39][40][41][42][43][44][45][46][47]. HCC typically shows an increase in arterial liver perfusion (Fig.…”

Fundamentals of tracer kinetics for dynamic contrast‐enhanced MRI

“…However, the interstitial compartment (EES) may have a larger radial dimension (compared with its axial dimension) without a radial concentration gradient, and can be regarded as largely homogeneous. The impulse residue function for DP2 model can be given by two physiologic phases (63)(64)(65)(66)(67)(68)(69):…”

“…Also, by setting E or PS ¼ 0, the single-(vascular) compartment DP model, R DP1 (t), is simply given by R p (t). The physiological meaning of the two transport phases can be explained as follows (63)(64)(65)(66)(67)(68)(69). During the initial vascular transit phase 0<t<t p , R p (t) is a constant (unity) reflecting the fact that the total amount (100%) of tracer in the injected bolus is residing in the tissue, although a portion of the tracer could diffuse from the IVPS into EES.…”

“…The above DP models have been previously used in DCE CT studies of various tumors (8)(9)(10)(11)65,68) and are gaining popularity in DCE MRI (73)(74)(75)(76)(77)(78)(79). However, recent studies have raised concerns about the presence of discontinuities in the impulse residue functions of DP models which could result in convergence problems during fitting, leading to reduced parameter precision (75,(77)(78)(79).…”

Registration of Free-Breathing Abdominal 3D Contrast-Enhanced CT

“…However, it is possible to get relevant information only if data are correctly registered. Two main approaches are possible to deal with respiratory motion, sequential breath hold [1] or free-breathing. In the present study, free breathing is selected, since a less stressed patient usually provides sequences with more regular motion.…”