Contrast-enhanced, real-time volumetric ultrasound imaging of tissue perfusion: preliminary results in a rabbit model of testicular torsion.

Contrast-enhanced ultrasound (US) imaging is potentially applicable to the clinical investigation of a wide variety of perfusion disorders. Quantitative analysis of perfusion is not widely performed, and is limited by the fact that data are acquired from a single tissue plane, a situation that is unlikely to accurately reflect global perfusion. Real-time perfusion information from a tissue volume in an experimental rabbit model of testicular torsion was obtained with a two-dimensional matrix phased array US transducer. Contrast-enhanced imaging was performed in 20 rabbits during intravenous infusion of the microbubble contrast agent Definity® before and after unilateral testicular torsion and contralateral orchiopexy. The degree of torsion was 0° in 4 (sham surgery), 180° in 4, 360° in 4, 540° in 4, and 720° in 4. An automated technique was developed to analyze the time history of US image intensity in experimental and control testes. Comparison of mean US intensity rate of change and of ratios between mean US intensity rate of change in experimental and control testes demonstrated good correlation with testicular perfusion and mean perfusion ratios obtained with radiolabeled microspheres, an accepted 'gold standard'. This method is of potential utility in the clinical evaluation of testicular and other organ perfusion.

Transcranial Doppler analysis of cerebral hemodynamics in primary craniosynostosis: study in progress.

BACKGROUND: Regional elevations in intracranial pressure (ICP) have been monitored adjacent to areas of cranial stenosis by some authors [9,19,20]; however, noninvasive techniques such as transcranial Doppler (TCD) would be preferable if increased ICP could be detected just as reliably. METHODS: TCD examinations of basal cerebral arteries were performed in 31 children with skull deformities. Skull X rays and computed tomography (CT) scans or magnetic resonance imaging (MRI) were analyzed for degree of cranial vault abnormality, as well as for presence or absence of intracranial pathology. Neurodevelopmental examination and clinical signs of increased ICP, if any, were recorded. RESULTS: The overall incidence of increased resistivity indices (RI) was 70%. Patients with asymmetric skull deformities (plagiocephaly) or sagittal synostosis (scaphocephaly) were statistically more prone to exhibit increased RI compared to previously reported prevalences. CONCLUSIONS: Because TCD is a convenient, rapid, accurate, and noninvasive method by which to gauge ICP, it should be considered in the preliminary work-up of a patient with craniosynostosis.