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F Tranquart

Publications and source records attributed to F Tranquart.

At least 19 recordsLinked to original sources
PubMed2006

Diagnostic accuracy of contrast-enhanced ultrasound in focal lesions of the liver using cadence contrast pulse sequencing.

UNLABELLED: The purpose of this study was to assess the accuracy of Cadence Contrast Pulse Sequencing (Siemens-Acuson, CA) method with injection of SonoVue (Bracco Imaging SpA, Italy) for the detection and characterisation of focal liver lesions in comparison with a reference modality during routine use. METHODS: 138 consecutive patients (62 women, 76 men; mean age: 52 years for women and 63 years for men) corresponding to 144 examinations with 381 lesions participated in this prospective study from December 2002 to November 2003. Inclusion criteria were lesions detected by conventional US and the availability of a reference imaging examination (CT or MR imaging) within three weeks. The underlying liver lesions characterised by a reference modality (including biopsy in 29 lesions) were distributed as follows: haemangioma (n = 56), focal nodular hyperplasia (n = 27), hepatocellular carcinoma (n = 44), hepatocellular adenoma (n = 5), liver metastasis (n = 174), abscess (n = 2), cysts (n = 45), other benign lesions (n = 24) and 3 peritoneal metastases. RESULTS: A significant improvement was reported in the number of detected lesions between contrast-enhanced ultrasound and baseline ultrasonography (351 lesions versus 280 lesions, respectively, p < 0.01), whereas no significant difference was noted between contrast-enhanced ultrasound and reference imaging (351 versus 377 lesions, respectively). On the whole, contrast-enhanced ultrasound allowed a complete diagnosis in 96 % of the detected nodules with a significant improvement compared to conventional sonography in which the diagnosis was suspected in only 52 % out of these cases (p < 0.001). No significant difference was noted between contrast-enhanced ultrasound and the reference modality concerning characterisation of nodules. CONCLUSION: The present study clearly indicates that contrast-enhanced sonography using Sonovue and Cadence Contrast Pulse Sequencing allows real-time imaging with high accuracy and thus will be a competitive alternative to other modalities such as CT and MR imaging for liver imaging.

Adult↗
PubMed2005

A posteriori respiratory gating in contrast ultrasound for assessment of hepatic perfusion.

An original strategy is proposed to minimize the impact of respiratory motion on hepatic contrast-enhanced ultrasound studies. It is based on the a posteriori triggering of dynamic image sequences. It was tested on perfusion studies acquired with a high temporal resolution (8 images s-1) to enable parametric imaging. A respiratory component was first estimated by independent component analysis. The estimation of the local minima and maxima of this curve enabled us to select two subsets of frames, corresponding to the end-of-inspiration plane and to the end-of-expiration plane. Both subsets were simultaneously analysed using factor analysis of medical image sequences. This method identified the main contrast uptake kinetics and their associated localizations. The global strategy was validated firstly on a simulated study and then applied to 11 patients' studies. In both cases, the frame selection was judged relevant and a necessary preliminary step before applying methods of parametric imaging. In conclusion, the a posteriori gating method that is proposed is a first step towards local quantification of hepatic contrast-enhanced ultrasound studies.

Computer Simulation↗
PubMed2005

Power Doppler vascularity index for predicting malignancy of adnexal masses.

OBJECTIVE: To assess the performance of a power Doppler vascularity index in the preoperative diagnosis of ovarian malignancy. METHODS: Adnexal masses (n = 101) were examined prospectively with power Doppler ultrasonography before surgical treatment. The tumor vascularity index (power Doppler index, PDI) was determined by quantification of the number of pixels in a defined region of interest according to the formula: number of colored pixels/(total number of pixels minus the number of pixels in the fluid or avascular areas). It was estimated on selected frames of the tumors using an in-house color-quantifying program added to MATLAB 6.0 software. Inter- and intraobserver reproducibilities of PDI assessment were evaluated. Intratumoral blood flow velocity waveforms were obtained to determine the lowest resistance index (RI). A subjective visual score of power Doppler signals in the tumor was used to classify it as having low, moderate or high vascularity. The discriminatory ability of this score was compared to that of RI and PDI measurement. RESULTS: Histology identified 23 malignant and 78 benign lesions. The PDI was considerably higher in malignant than in benign lesions (0.34 +/- 0.04 vs. 0.12 +/- 0.06; P < 0.001). The intra- and interobserver variabilities of PDI were low (intraclass correlation coefficients of 0.99 and 0.97, respectively). The PDI cut-off value to differentiate malignant from benign tumors was set at 0.265 (26.5% of the tumor being colored). Using this cut-off, sensitivity and specificity were 100% (95% CI, 87.8-100.0) and 97.4% (95% CI, 91.0-99.7) compared to 78.3% (95% CI, 56.3-92.5) and 83.1% (95% CI, 72.9-90.7) for RI (cut-off value of 0.53) and 78.3% (95% CI, 56.3-92.5) and 94.9% (95% CI, 87.4-98.6) for visual scoring. Logistic regression demonstrated that PDI was the best parameter for differentiating between malignant and benign tumors. CONCLUSION: The power Doppler vascularity index obtained using customized color quantifying software has high diagnostic value in discriminating between benign and malignant adnexal masses.

Adnexa Uteri↗
PubMed2004

Contrast-enhanced sonography during uterine artery embolization for the treatment of leiomyomas.

Uterine artery embolization (UAE) is a successful and safe treatment for symptomatic leiomyomas. However, rare complications such as premature menopause and uterine necrosis can arise because of embolization of non-target tissues. We studied the feasibility of using contrast-enhanced sonography with intravenous SonoVue just before, during and after complete occlusion of both uterine arteries. In a patient with multiple, large, symptomatic leiomyomas, contrast-enhanced imaging established that the UAE was technically successful and that myometrial vascularity was not reduced. Our case suggests that ultrasound contrast agents may have a role in monitoring UAE and thus may help prevent ischemic complications. Further studies are required to confirm this.

Arteries↗
PubMed2004

Incidental liver lesions: diagnostic value of cadence contrast pulse sequencing (CPS) and SonoVue.

The widespread use of modern imaging modalities has led to an increase in the frequency of detecting coincidental focal liver lesions (cysts, haemangiomas, focal nodular hyperplasia, adenoma, focal fatty sparing and infiltration) in patients with no symptoms of liver disease. A positive diagnosis is needed to avoid overinvestigation or protracted follow-up. The limitations of conventional sonography have led to the use of other imaging modalities and invasive or costly procedures such as CT, MRI or biopsy. The availability of real-time contrast-enhanced ultrasound imaging (CEUS) has changed the strategy in the characterization of such lesions without inconvenience for the patient. Cadence contrast pulse sequencing (CPS) gives strong contrast signals as well as simultaneous acquisition of conventional scans for a perfect match of these two images. In our personal experience, in comparison with reference imaging, CPS with SonoVue has differentiated benign from malignant lesions in all cases and has accurately characterized 96% of lesions. These results are slightly better than those reported in the literature, probably because of the higher sensitivity of CPS in detecting bubbles, whether flowing or stationary, and also because of the possibility of matching simultaneously recorded contrast and conventional images which reinforces confidence in lesion assessment. The high diagnostic value of CEUS makes this method a candidate to be considered a reference imaging modality for incidental lesions.

Contrast Media↗
PubMed2004

[Pulsed transcranial Doppler examination in the acute phase of stroke].

INTRODUCTION: Transcranial pulsed Doppler sonography with or without imagery is used in the acute phase of ischemic stroke in order to define stroke mechanism and intracranial hemodynamic consequences. STATE OF ART: This non-invasive low-cost investigation can be undertaken rapidly, within 10 minutes if guided by focal symptomatology. It detects middle cerebral artery stenosis in >or=50 p. cent of cases with a sensitivity between 75 and 90 p. cent, comparatively with conventional angiography, and middle cerebral artery occlusion with 90 p. cent sensitivity. When a temporal acoustic window is lacking, intravenous injection of a contrast agent allows good visualization of the intracranial vessels and the circle of Willis, in two-third of cases. Moreover, transcranial Doppler data have good prognostic value and facilitate analysis of recanalization after thrombolytic therapy. CONCLUSION: Beside its diagnostic and prognostic interest, transcranial Doppler sonography using a 2 MHz frequency appears to have therapeutic impact by favoring the thrombolysis process. Future developments may include early and prolonged insonation of patients suffering from stroke.

Brain Ischemia↗
PubMed2004

[Feasability of real time contrast enhanced ultrasound in renal disease].

OBJECTIVES: To evaluate feasibility of real-time contrast enhanced ultrasound in renal disease. MATERIALS AND METHODS: Eighteen patients (sex-ratio=1: mean age 62.3 +/-18.1 years) presenting with several renal diseases were enrolled in the present study. Real time contrast enhanced sonography was performed using an ultrasound dedicated system Esatune (Esaote, Firenze, Italy) with a very low mechanical index (MI<0.1) and a dedicated contrast software CnTI after bolus injection of 2.4 ml Sonovue (Bracco, Milan, Italy). Detection, characterization and extension of renal masses as well as inflammatory and ischemic lesions were evaluated. The results were compared to those obtained by reference method such as contrast-enhanced CT-Scan or MRI. RESULTS: This preliminary study gave some valuable results compared to baseline sonography: marked improvement in tumor delineation or internal microvasculature, detection of venous extension, improvement in cystic mass characterization. Diagnosis confidence was improved and reached 83% when diagnosis concordance with reference modality was improved by 50%. CONCLUSION: These preliminary results show that real-time contrast enhanced sonography could improve detection and characterization of renal masses by a complete assessment or arterial phase. Further studies are required to confirm these first results with possible advantages for the diagnosis of renal affections.

Adult↗
PubMed2004

[Contrast ultrasound imaging in focal liver lesions: diagnostic value and guidelines].

The recent introduction of high quality scanners and contrast agents for ultrasound deeply modifies diagnosis strategy in focal liver lesions by using validated criteria. Non-linear imaging methods using low mechanical index (MI<0.2) and second generation contrast agents allow real-time continuous imaging with concomitant limitation in background tIssue signal and also in agent collapse for a high quality contrast imaging giving dramatic improvement in detection and characterization of lesions. Interpretation is based on the presence of contrast agent within the lesion or not (hyper-, hypo- or isosignal) and the delay after injection (arterial, portal or parenchymal or late phase) as previously used by non-ultrasound methods. This allows an easy differentiation of benign from malignant lesions. Moreover, this allows complete characterization in 85 to 95% of all focal liver lesions and 75% in hepatocellular carcinomas. Those results markedly improve ultrasound accuracy compared to conventional sonography and so put contrast-enhanced sonography among recommended non-invasive imaging methods for focal liver lesions with changes in diagnostic strategy according to the lesion type and actual place of US methods. It is recommended to use contrast ultrasound methods in cancer staging for an optimal detection of liver metastases as well as in characterization of lesions detected during conventional sonography with a consecutive decrease of cost-diagnosis ratio.

Carcinoma, Hepatocellular↗
PubMed2004

[Value of combined conventional and contrast enhanced sonography in the evaluation of hepatic disorders].

PURPOSE: To assess the value of combined conventional and contrast-material enhanced sonography for the characterization of focal liver lesions. MATERIALS AND METHODS: Simultaneous imaging with grey scale and contrast enhanced US was performed in 90 patients following Levovist injection (Schering, Berlin, Germany) using the "Agent Detection Imaging" method (ADI, Siemens-Acuson, Mountain View, USA). US scanning was performed at least 4 minutes after contrast injection with review of both grayscale and contrast enhanced modes. Results for detection and characterization of lesions were compared to the selected gold standard imaging modality (CT or MRI). RESULTS: Final diagnoses included: 20 normal examinations, 41 patients with metastases, 6 patients with hepatocellular carcinoma, 13 patients with hemangioma, 6 patients with other benign lesions, 4 patients with cysts and 6 patients with two types of lesions. Delayed phase contrast enhanced US allowed diagnosis of all lesions except for one metastasis and all hepatocellular carcinomas. While the diagnosis of hepatoma could not be confirmed, the features suggested a malignant etiology. For 7 patients with metastases, more lesions were detected at ADI (4.9 lesions) than at conventional US (1.1 lesion). For 3 patients, CT showed more lesions than ADI US (3.3 versus 1.6 lesions). The accuracy of ADI US for differentiating between benign and malignant lesions was 98.7% compared to 49.6% for conventional US (p<0.001). The total number of lesions detected at ADI US was higher (p<0.01) than at conventional US and not significantly different from that obtained by the gold standard reference methods. Complete characterization was achieved in 92.2% of cases with ADI US compared to 59.2% with conventional US (p<0.001). CONCLUSION: Contrast-material enhanced US combined with conventional US markedly improves the diagnostic accuracy of US in terms of lesion detection and characterization.

Adult↗
PubMed2003

Viral and bacterial DNA in carotid atherosclerotic lesions.

Atherosclerosis is a major health problem in industrialised countries. Several studies have suggested an association exists between certain microorganisms and the development of atherosclerosis. The aim of the study presented here was to assess the presence of viral or bacterial DNA in carotid atherosclerotic lesions. Nucleic acids were extracted from 18 carotid atherosclerotic lesions that had been collected surgically. Polymerase chain reaction was used to screen for specific genomic DNA from Chlamydia pneumoniae, cytomegalovirus and herpes simplex virus types 1 and 2. An original approach, based on the amplification by PCR of conserved bacterial 16S rDNA nucleotide sequences was also used to detect any bacterial species. The amplification product was identified by sequencing. Chlamydia pneumoniae, cytomegalovirus and herpes simplex 2 DNA were not detected in any of the samples. Herpes simplex 1 DNA was detected in 3 of the 18 samples. Genes encoding bacterial 16S rRNA were amplified and sequenced in eight atherosclerotic lesions. DNA sequences were identified by comparison with sequences registered in the GenBank database. These eight carotid atherosclerotic lesions were shown to contain several bacterial species belonging to human flora or the environment. The exact role of these microorganisms in the genesis or development of the atherosclerotic lesions remains unclear, but they may increase the inflammatory process or be an epiphenomenon.

Aged↗
PubMed2003

[Detection modes of ultrasound contrast agents].

Ultrasound contrast agents have been used for many many years in cardiology. Their application in other fields is more recent, related to the availability of agents that can pass through the pulmonary circulation. Physical properties of contrast microbubbles are closely bound to their gas content, shell composition, frequency of ultrasound beam, pulse repetition frequency, acoustic power and wave phase. Specific ultrasound sequences have to be used to adequately exploit microbubble-specific interactions with the ultrasound beam. The aim of this paper is to review physical properties of ultrasound contrast agents, present imaging sequences developed for optimal use of these contrasts and general applications.

Artifacts↗
PubMed2003

[Contrast ultrasound imaging in liver disease].

The recent introduction of high-end ultrasound equipments combined with the introduction of contrast agents provides marked improvements in liver imaging for the detection and the characterization of focal lesions. Previous imaging methods were based on high acoustic power and demonstrated improved detection of focal liver lesions. However, good and reliable results were difficult to achieve due to limited number of sweeps, as most of the microbubbles were destroyed within one pass. Non linear imaging methods at low acoustic power allowed great advances in the characterization by limiting signal from background tissue as well as agent collapse allowing continuous imaging starting from the time of contrast injection until complete disappearance of the agent. Contrast-enhanced imaging of the liver follows conventional sonography performed with high standards for detection and localization of lesions using multiple sweeps. Then targeted acquisition is performed for specific lesion characterization after a second contrast injection. Interpretation is based on the presence or not of microbubbles within the lesion (hyper-, hypo- or isosignal) and the delay from injection (arterial, portal or parenchymal or late phase). A well-recognized semiology is reported in this paper. Based on these criteria, sensitivity and specificity are close to those reported with other modalities with accuracy 85-95% for focal liver lesions and 75% for hepatocellular carcinomas. Those results markedly improve ultrasound accuracy compared to conventional sonography, and so put contrast-enhanced sonography among recommended non-invasive imaging methods for focal liver lesions with changes in diagnostic strategy.

Aged↗
PubMed2003

[Contrast-enhanced ultrasonography: renal applications].

Color Doppler US of the urinary tract is still facing a few limitations including, for B-mode imaging, the detection of small lesions, and, for color Doppler, the detection of low flow. Ultrasound contrast agents (USCA) improve these two limitations and allow the development of new functional applications for renal blood flow quantification. This improvement results from an increased acoustic response obtained from the microbubbles, as well as from the development of pulse sequencing and signal processing that led to the concept of specific ultrasound sequences. Most of the clinical indications of contrast-enhanced ultrasonography remain to be validated with the improved detection of the non linear response. USCA improve the detection of abnormal micro and macrovascular disorders of the kidney, particularly for the detection and the characterization of renal artery stenosis, as well as for the visualization of renal infarction. This technique showed potentials for the study of renal masses, especially atypical cystic lesions. Among the remaining indications, the detection of reflux and testicular torsion are the most promising.

Adult↗
PubMed2003

[Sonographic diagnosis of ovarian tumors: pre-operative Doppler evaluation].

Pelvic sonography is the gold standard for diagnosis of ovarian masses. Only 2% of adnexal masses or malignant or bordeline tumors. Does Doppler US improve the diagnostic accuracy of sonography? The purpose of this article is to review current data and identify what areas still require further evaluation with regards to Doppler characterization of adnexal masses. It has been shown that Doppler evaluation of the ovary and cyst or tumor improves the diagnostic accuracy of US to differentiate between benign and malignant lesions. Hemodynamic data collected from pulsed Doppler imaging and Doppler energy vascular mapping have been shown to improve the characterization of malignant lesions. These data improve the accuracy of B-mode US combined with clinical evaluation and CA125 measurement. Nonetheless, the sensitivity and specificity values are between 85-90%, with few missed malignancies, but several false positive results. Useful Doppler data include the resistive index and the central intratumoral location of vascular flow. The use of 3D US with computer post-processing as well as sonographic contrast agents could provide additional information, but these techniques have not yet been validated. All suspicious adnexal lesions should be evaluated by an experienced sonographer and include discriminatory parameters to distinguish between benign and malignant lesions.

Female↗