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Biomedical subjects

J-Y Meuwly

Publications and source records attributed to J-Y Meuwly.

5 recordsLinked to original sources

[Percutaneous image-guided breast biopsy].

Breast cancer is the most frequent cancer among women. Screening programs are able to diagnose early lesions in an infra-clinic state. Percutaneous procedures are simple to do and well tolerated by women, they provide an histological diagnosis. This way of doing may reensure rapidly, without a surgical approach, the women with benign lesions. In cases of invasive cancers, percutaneous procedures are also able to optimize the ongoing therapeutic strategy. The type of the radiological anomaly determines the technical guidage of the procedure and the type of material. Ultrasonographic guidage is used for opacities and needles of small size can be used (micro-biopsy). With microcalcifications, the guidage is made with mammographic stereotaxis, these lesions are usually complex and they need needles of big size (macrobiopsy).

Biopsy, Needle↗

[Current value of sonography for the detection of focal liver lesions].

Current value of sonography for the characterization of focal liver lesions Incidental focal lesions are frequently discovered during sonographic exploration of the liver. Solid lesions remain often questionable, particularly in oncological or infectious patients. Doppler exploration generally doesn't help and other modalities, such as CT, MRI or even biopsy are necessary to definitively categorize the lesion. Ultrasound contrast agents associated with contrast detection ultrasound mode give the opportunity to follow the blood flow until the capillary level. Thus the dynamical behavior of blood flow in tissue is now observable with US, as it was previously with CT or MRI alone. The aim of this paper is to review the actual knowledge about the characterization of focal liver lesions with sonographic dynamic enhancement and to discuss the advantages and limitations of this particular technique.

Contrast Media↗

[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↗

Life-threatening vascular complications after central venous catheter placement.

The purpose of this retrospective study was to report 11 cases of severe vascular complications after central venous catheter misplacement. For each patient, data collection included body mass index, the diagnosis at admission, the site of the procedure, the type of catheter, coagulation parameters, the imaging modalities performed and the applied treatment. Eight patients had a lesion of the subclavian artery. Brachiocephalic vein perforations were assessed in three more patients. All patients had a chest roentgenogram after the procedure, six a CT examination, and four an angiographic procedure. Seven patients had a body mass index above 30, and 5 patients had coagulation disorders prior to the procedure. Seven patients were conservatively managed, 2 patients died despite resuscitation, 1 patient was treated with a stent graft, and one by superselective embolization. Subclavian or jugular vein temporary catheter positioning is a practical approach. Identification of any iatrogenic perforation of the subclavian artery or central veins urges obtaining a chest roentgenogram and, when required, a chest CT, selective angiograms or venograms. Body mass index superior to 30, previous unsuccessful catheterization attempts, and coagulation factor depletion seemed to account for risk factors. Recognition of clinical and radiological complications is mandatory.

Adult↗