Frédéric Cohen

Measurement of trabeculated left ventricular mass using cardiac magnetic resonance imaging in the diagnosis of left ventricular non-compaction

AIMS To describe a method for measuring trabeculated left ventricular (LV) mass using cardiac magnetic resonance imaging and to assess its value in the diagnosis of left ventricular non-compaction (LVNC). METHODS AND RESULTS Between January 2003 and 2008, we prospectively included 16 patients with LVNC. During the mean period, we included 16 patients with dilated cardiomyopathy (DCM), 16 patients with hypertrophic cardiomyopathy (HCM), and 16 control subjects. Left ventricular volumes, LV ejection fraction, and trabeculated LV mass were measured in the four different populations. The percentage of trabeculated LV mass was almost three times higher in the patients with LVNC (32 +/- 10%), compared with those with DCM (11 +/- 4%, P < 0.0001), HCM (12 +/- 4%, P < 0.0001), and controls (12 +/- 5%, P < 0.0001). A value of trabeculated LV mass above 20% of the global mass of the LV predicted the diagnosis of LVNC with a sensitivity of 93.7% [95% confidence interval (CI), 71.6-98.8%] and a specificity of 93.7% (95% CI, 83.1-97.8%; kappa = 0.84). CONCLUSION The method described is reproducible and provides an assessment of the global amount of LV trabeculation. A trabeculated LV mass above 20% of the global LV mass is highly sensitive and specific for the diagnosis of LVNC.

Ethylene vinyl alcohol copolymer (Onyx®) in peripheral interventional radiology: indications, advantages and limitations.

Onyx(®) is a remarkable liquid embolizing agent that may allow a well-trained operator to undertake challenging embolization procedures. In multiple interventional radiology indications, the physico-chemical properties of Onyx(®) allow safe embolization. The purpose of this article is to review the advantages and disadvantages of Onyx(®) and identify its main indications.

Prognostic value of preoperative coronary computed tomography angiography in patients treated by orthotopic liver transplantation.

Objectives The aim of this study was to assess the feasibility of 64-slice coronary computed tomography (CT) angiography in patients treated by orthotopic liver transplantation, and to compare prognostic values of CT angiography and dobutamine stress echocardiography in the same population. Methods Eighty-two consecutive patients, without known coronary artery disease, who underwent orthotopic liver transplantation, were included in this study. A CT angiography was performed along with usual explorations including dobutamine stress echography. A one-year minimal follow-up was performed to seek cardiac events. Results Fifty-two (65.8%) patients underwent a CT angiography. Thirty-seven (71%) were totally normal or showed nonobstructive coronary plaque, six (12%) showed at least one obstructive coronary plaque greater than 50%. Nine (17%) of the examined patients had at least one nonassessable segment. A total of six (7.6%) major cardiac events occurred in a mean-time follow-up of 17.8±12.7 months. Conclusion CT angiography that is normal or with a nonobstructive coronary plaque has a negative predicting value of 95% [0.82–0.99] for major cardiac adverse events, and of 100% [0.91–1] for clinical coronary events in patients undergoing orthotopic liver transplantation. The prognostic value of CT angiography was comparable with that of dobutamine stress echography.

Pathological effects of lung radiofrequency ablation that contribute to pneumothorax, using a porcine model

Abstract Objectives: The incidence of pneumothorax is 7 times higher after lung radiofrequency ablation (RFA) than after lung biopsy. The reasons for such a difference have never been objectified. The histopathologic changes in lung tissue are well-studied and established for RF in the ablation zone. However, it has not been previously described what the nature of thermal injury might be along the shaft of the RF electrode as it traverses through normal lung tissue to reach the ablation zone. The purpose of this study was to determine the changes occurring around the RF needle along the pathway between the ablated zone and the pleura. Material and methods: In 3 anaesthetised and ventilated swine, 6 RFA procedures (right and left lungs) were performed using a 14-gauge unipolar multi-tined retractable 3 cm radiofrequency LeVeen probe with a coaxial introducer positioned under CT fluoroscopic guidance. In compliance with literature guidelines, we implemented a gradually increasing thermo-ablation protocol using a RF generator. Helical CT images were acquired pre- and post-RFA procedure to detect and evaluate pneumothorax. Four percutaneous 19-gauge lung biopsies were also performed on the fourth swine under CT guidance. Swine were sacrificed for lung ex vivo examinations, scanning electron microscopy (SEM) and pathological analysis. Results: Three severe (over 50 ml) pneumothorax were detected after RFA. In each one of them, pathological examination revealed a fistulous tract between ablation zone and pleura. No fistulous tract was observed after biopsies. In the 3 cases of severe pneumothorax, the tract was wide open and clearly visible on post procedure CT images and SEM examinations. The RFA tract differed from the needle biopsy tract. The histological changes that are usually found in the ablated zone were observed in the RFA tract’s wall and were related to thermal lesions. These modifications caused the creation of a coagulated pulmonary parenchyma rim between the thermo-ablation zone and the pleural space. The structural properties of the damage can explain why the RFA tract is remains patent after needle withdrawal. Conclusion: Our study demonstrates for the first time that the changes around the RF needle are the same as in the ablated zone. The damage could create fistulous tracts along the needle path between thermo-ablation zone and pleural space. These fistulas could certainly be responsible for severe pneumothorax that occurs in many patients treated with lung RFA.

Postmortem Whole Body CT Angiography Using Aqueous Contrast Agent

In modern postmortem imaging, the visualization of the vascular system by postmortem angiography is mostly done using multidetector computed tomography (CT). Like clinical radiologic investigations, whole body angiography makes the vascular system visible and allows identification of vascular lesions such as traumatic dissection or rupture. Additionally, the injection of contrast agent enhances soft tissue and aids in the visualization of lesions in organ parenchyma. In this chapter, we describe two methods of whole body postmortem CT angiography (PMCTA) that can be classed in the category of “PMCTA using aqueous contrast agent.”

Hemorrhages of the ENT Area

Arterial embolization is the treatment of choice for refractory epistaxes and can be indicated in hemorrhages of the ENT area. When carried out by trained radiologists, it proves to be an efficient method that presents little risk of complications.

Lymphome développé dans l’espace épicardique

Un homme de 65 ans est hospitalise pour le bilan d’une dyspnee rapidement progressive. le bilan echographique revele la presence d’une masse cardiaque droite et de masses surrenaliennes bilaterales. Une IRM est demandee pour completer le bilan.

Bourrelet graisseux de la veine cave

Patiente de 45 ans, obese, chez qui on retrouve, sur un scanner demande pour le bilan d’une douleur abdominale, une masse dans la veine cave inferieure retrohepatique. Une IRM et un scanner sont demandes pour l’exploration de cette masse.

Malformation vasculaire de type veineuse intracardiaque (ancien hémangiome)

Patient de 55 ans qui nous est adresse pour la realisation d’une IRM devant la decouverte d’une masse dans l’oreillette droite. Ce patient est asymptomatique et ne presente pas d’antecedent particulier.

Thrombus au cours des cardiomyopathies dilatées (CMD)

Monsieur F., 80 ans, est hospitalise pour decompensation cardiaque globale. Son echocardiographie montre une dilatation cardiaque globale et une fraction d’ejection diminuee. L’IRM est demandee pour faire le bilan etiologique de cette cardiomyopathie de decouverte recente.