Early modifications of hepatic perfusion measured by functional CT in a rat model of hepatocellular carcinoma using a blood pool contrast agent

Abstract

Macromolecular contrast-enhanced functional CT was performed to characterize early perfusion changes in hepatocellular carcinoma (HCC). Fourteen rats with chemically induced primary liver tumors ranging pathologically from hyperplasia to HCC and 15 control rats were investigated. Two dynamic CT scans using an experimental macromolecular contrast agent were performed on a single slice 11 and 18 weeks after tumor induction followed by pathological examination. A deconvolution mathematical model was applied, yielding the hepatic perfusion index (HPI), mean transit time (MTT), liver distribution volume (LDV) and arterial, portal and total blood flows (FA, FP, FT). Analysis was performed on one slice per rat, containing overall two hyperplasia, six dysplasia and 15 HCC. On the first scans, HCC at an early pathological stage had a low FP (-30%, P=0.002) but a normal arterial-portal balance. On the scan contemporary to pathology, HCC perfusion parameters showed an inversion of the arterial-portal balance (HPI +212%, P<0.0001), with a high FA (+56%, P=0.002) and a low FP (-69%, P<0.0001). Sensitivity and specificity of detection of HCC by perfusion CT were high (87 and 80%) on late scans; but also on the earlier scans (86 and 65%), even though only one (7%) was visible to the eye. Perfusion-CT allowed early detection of HCC. This technique could contribute in the detection and characterization of liver lesions in clinical studies.

Computed tomography perfusion in evaluating the therapeutic effect of transarterial chemoembolization for hepatocellular carcinoma

“…In addition, many CT perfusion analyses were performed using a single arterial input [8,9,15] , but the liver has a dual arterial-portal blood supply, and the tumor and portal vein could not be consistently included. In our study, 64-rows multi-detector CT was introduced to offer a greater coverage (up to 4 cm), thus overcoming this limitation by including both the tumor and portal vein in dual-input analysis.…”

“…CT examination after TACE has been widely used to assess the efficacy of TACE [6] , but its limitation is that a quantitative evaluation cannot be provided and an incomplete lipiodol accumulation may disturb the assessment of viable tumors on contrastenhanced CT imaging [7] . Alternatively, CT perfusion imaging is a non-invasive technique for assessment of tissue perfusion in locally advanced HCC [8][9][10] . The response to TACE may be evaluated by comparing the difference in perfusion parameters pre-and post-treatment [11,12] .…”

Perfusion characterization of liver metastases from endocrine tumors: Computed tomography perfusion

“…Fabiano et al [10] and Wang et al [11] also have found differences between the values of the CT p parameters of benign and malignant liver lesions. Fournier et al [12] have previously identified differences in CT p values between regenerative and dysplastic carcinomatous nodules, which allowed early detection of HCC. Tsushima et al [13] have performed a comparative study to evaluate CT p of HCC and liver metastases of colorectal origin.…”

Renal Perfusion and Hemodynamics: Accurate in Vivo Determination at CT with a 10-Fold Decrease in Radiation Dose and HYPR Noise Reduction

“…The timeattenuation curve (TAC) over the tissue or organ of interest is used, with various models of single-and multiple-compartment flow, to estimate parameters such as absolute blood flow and volume and vascular permeability (1)(2)(3). For oncologic applications, increased tissue perfusion has been studied to assess tumor malignancy and potential response to therapy, while in ischemic disease applications, blood flow is correlated to tissue viability (1,(4)(5)(6)(7). Thus, CT perfusion imaging may have a clinical role in both oncologic and cardiovascular applications.…”