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Laure S Fournier

Publications and source records attributed to Laure S Fournier.

5 recordsLinked to original sources
PubMed2005

Initial computed tomography imaging experience using a new macromolecular iodinated contrast medium in experimental breast cancer.

OBJECTIVE: The objective of this study was to evaluate computed tomography (CT) enhancement characteristics for a new iodinated macromolecular contrast medium (MMCM), PEG12000-Gen4-triiodo, for angiographic effect and for assessment of abnormal vascular permeability in cancer. MATERIALS AND METHODS: Time persistence of angiographic effect was evaluated on rat CT images acquired over 30 minutes using the iodinated polyethyleneglycol- (PEG) based macromolecule. Dynamic CT imaging after PEG12000-Gen4-triiodo-enhancement in tumor-bearing rats was used to quantitatively estimate plasma volume and microvascular transendothelial permeability for both tumor and normal soft tissue. Using identical doses of iodine, 300 mg iodine/kg, blood curves for this MMCM and iohexol were compared. RESULTS: Serial whole-body CT angiograms using PEG12000-Gen4-triiodo showed diagnostic vascular detail through 20 minutes, and the blood enhancement curve was higher and more persistent than with small-molecular iohexol. Permeability estimates were significantly (P<0.02; paired t test) higher in tumors (48.2+/-18.1 microL/min-1 100 mL) than in muscle (2.5+/-5.7 microL/min-1 100 mL). CONCLUSIONS: Use of PEG-based MMCM for experimental CT allowed for a persistent angiographic enhancement and for quantitative estimation of tumor microvascular characteristics.

Animals↗
PubMed2004

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

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.

Animals↗
PubMed2004

Magnetic resonance imaging detects early changes in microvascular permeability in xenograft tumors after treatment with the matrix metalloprotease inhibitor Prinomastat.

Macromolecular contrast medium-enhanced magnetic resonance imaging was applied to monitor the effect of matrix metalloprotease (MMP) inhibition on microvascular characteristics of human breast cancers implanted in athymic rats. Twice-daily intraperitoneal administration of Prinomastat over 1.5 days induced significant declines in MRI-assayed microvascular permeabilities (p<0.05); but this leak suppression effect had extinguished by the 10(th) day of MMP treatment using the same dose and time schedule. Results demonstrate that Prinomastat produces a rapid but transient decrease in tumor vascular permeability. Contrast-enhanced MRI using macromolecular contrast medium may prove useful as a biomarker for the dynamic MMP biological effect in cancers.

Animals↗
PubMed2002

Can CT replace bronchoscopy in the detection of the site and cause of bleeding in patients with large or massive hemoptysis?

OBJECTIVE: We assessed the capacity of chest radiography and CT to determine the cause and site of bleeding in patients with either large or massive hemoptysis compared with bronchoscopy. MATERIALS AND METHODS: We reviewed the chest radiographs, CT scans, and bronchoscopic findings in 80 patients with either large or massive hemoptysis who were admitted to our intensive care unit between January 1995 and June 1999. RESULTS: Findings on chest radiography were normal in only 13% of patients, of whom 70% had bronchiectasis. The chest radiographs revealed the site of bleeding in 46% of the patients and the cause in 35%, most of whom had tuberculosis or tumors. CT was more efficient than bronchoscopy for identifying the cause of bleeding (77% vs 8%, respectively; p < 0.001), whereas the two methods were comparable for identifying the site of bleeding (70% vs 73%, respectively; p = not significant). CONCLUSION: These data suggest that CT could replace bronchoscopy as the first-line procedure for screening patients with large and those with massive hemoptysis. However, these results must be confirmed in a prospective multicenter study.

Adult↗