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Biomedical subjects

M A Trambert

Publications and source records attributed to M A Trambert.

9 recordsLinked to original sources

Perflubron as an oral contrast agent for MR imaging: results of a phase III clinical trial.

PURPOSE: To assess perflubron for magnetic resonance (MR) imaging in the abdomen and pelvis in a multicenter trial. MATERIALS AND METHODS: MR images were obtained in 127 subjects before and after ingestion of perflubron with T1-, proton-density-, and T2-weighted sequences at 0.38, 1.0, or 1.5 T. Postcontrast images were compared with baseline images, and percentage of additional bowel darkened, distinction of bowel from adjacent tissue, and change in image artifact were graded. RESULTS: Perflubron increased the bowel darkening in over 92% of subjects with all sequences and field strengths. It improved definition of the left lobe of the liver and body and tail of the pancreas in 67%, 29%, and 42% of subjects, respectively, and of the uterus and bladder in 80% and 76%. Abnormal tissue was more conspicuous in 69% of subjects. Highest scores were achieved when the upper abdomen was imaged 5-30 minutes and the pelvis 10-40 minutes after ingestion. No image artifacts or side effects were attributed to perflubron. CONCLUSION: Perflubron is safe, and its efficacy was unaffected by pulse sequences, magnetic field strength, or time delay.

Abdomen

Perfluorocarbon-enhanced sonography: value in detecting acute venous thrombosis in rabbits.

OBJECTIVE: We have previously shown that perfluorocarbon emulsions administered i.v. act as contrast material during sonography by creating moving echoes in veins. Accordingly, we performed a study on rabbits designed to establish the value of perfluorocarbon-enhanced sonography in detecting acute venous thrombi. MATERIALS AND METHODS: Constriction of the inferior vena cava (IVC) just above the renal veins was established surgically in 15 rabbits. Thrombus was induced in the IVC in 10 of these; the other five served as controls. Gray-scale and color Doppler sonography were performed before and after the i.v. infusion of 3 ml/kg of perflubron emulsion (formulation AF0102, Alliance Pharmaceutical, San Diego, CA). Sonograms were evaluated for the presence and extent of thrombus. Three additional rabbits with percutaneously induced IVC thrombosis were studied before and after the i.v. administration of 0.2 ml of a preparation of microbubbles of perfluorocarbon gas (formulation PRD002, Alliance Pharmaceutical). In these animals thrombi were confirmed at autopsy. RESULTS: Unenhanced sonograms allowed detection of thrombi in the IVC in nine of the 10 animals with surgically induced thrombus but were inaccurate in determining clot extent. Filling the lumen of the IVC with moving echoes created by administration of perflubron emulsion allowed more complete delineation of the size and extent of thrombus and permitted detection of residual venous flow not observed on unenhanced scans. The perfluorocarbon gas microbubbles provided similar benefits. CONCLUSION: Our results show that i.v. administration of perflubron emulsion or perfluorocarbon gas microbubbles improves imaging of veins on sonography and may aid in the assessment of thrombi.

Acute Disease

Subacute scrotal pain: evaluation of torsion versus epididymitis with MR imaging.

Torsion knot and whirlpool patterns result from the twisting of the spermatic cord, which produces distortion of cord structures. These two findings, along with spermatic cord vascularity, were used to prospectively differentiate testicular torsion from epididymitis in 11 patients with subacute scrotal pain who underwent magnetic resonance (MR) imaging. The final diagnosis was established clinically in four patients and surgically in five. MR imaging enabled the recognition of each entity without error. Retrospective review of findings highlighted other potential discriminating features, the most important of which were testicular size and vascularity. Because of its ability to highlight vessels and detail normal and abnormal intrascrotal anatomy, MR imaging in this small series enabled the differentiation of subacute torsion from epididymitis with 100% accuracy. This high degree of accuracy warrants further investigation.

Adolescent

Cellular logic implementation on a generalized image processor applied to biomedical image processing.

The implementation on a generalized image processor of a cellular logic package that performs non-recursive cellular-logic operations (CLOs) in real time is described. This system takes advantage of up to 20 512 X 512 X 8-bit memory planes within the image processor and can manipulate cells with up to 256 symbolic states. The flexibility of the image processor allows the use of an expanded cellular transition set, beyond bit-on or bit-off, as well as application-specific neighborhood configurations. The use of concurrent data-dependent global calculations, including CLO iteration termination control, is described. The array processor implementation specifics are discussed. This general cellular logic package is applied to biomedical images in the Image Processing Laboratory, Department of Radiological Sciences, University of California at Los Angeles. Geometric information is acquired from the images using real-time operators on the image array processor. This information includes image segmentation, area calculation, object counting, centroid determination and shape analysis. Initial clinical results are presented, and possible future medical applications are discussed.

Computers

Cystosarcoma phyllodes of the prostate: MRI findings.

Cystosarcoma phyllodes of the prostate is a rare, relatively benign sarcoma of the prostate. We describe the magnetic resonance imaging findings in an unusual case of cystosarcoma phyllodes which resulted in extensive local recurrence and sarcomatous degeneration. Although uncommon, radiologists should be aware of the existence of cystosarcoma phyllodes of the prostate.

Aged

MR imaging of vasculitis of the testis.

Vasculitis of the testis, although common pathologically, has been difficult to diagnose clinically and to detect noninvasively. This report describes the added benefit of MR imaging in directing clinical management in a patient where the first manifestation of vasculitis was scrotal pain and swelling. This subject was diagnosed and treated for epididymitis. Although he had a normal appearing testis on sonography, magnetic resonance showed testicular changes more characteristic for focal infarcts which led to testicular biopsy and to altered diagnosis and treatment.

Humans