Singular value-guided similarity filter improves detection of vessels in low-dose dynamic CT angiography: application to DIEP flap studies.

Dynamic CT angiography provides much more information compared to static 3D CT angiography, in several clinical applications. The prolonged exposure, on the other hand, results in higher radiation dose for to the patient. Care should be taken when designing noise reduction algorithms so that temporal profiles and spatial resolution is not significantly compromised.

Noise reduction and functional maps image quality improvement in dynamic CT perfusion using a new k-means clustering guided bilateral filter (KMGB).

Purpose: Dynamic CT perfusion (CTP) consists in repeated acquisitions of the same volume in different time steps, slightly before, during and slightly afterwards the injection of contrast media. Important functional information can be derived for each voxel, which reflect the local hemodynamic properties and hence the metabolism of the tissue. Different approaches are being investigated to exploit data redundancy and prior knowledge for noise reduction of such datasets, ranging from iterative reconstruction schemes to high dimensional filters.

Advanced abdominal imaging with dual energy CT is feasible without increasing radiation dose.

Background: Dual energy CT (DECT) has proven its potential in oncological imaging. Considering the repeated follow-up examinations, radiation dose should not exceed conventional single energy CT (SECT). Comparison studies on the same scanner with a large number of patients, considering patient geometries and image quality, and exploiting full potential of SECT dose reduction are rare.

Cardiac responses elicited by stimulation of loci within stellate ganglia of developing swine.

Stimulation with bipolar electrodes of specific loci in stellate ganglia elicited in anesthetized piglets, 1-4 weeks of age, alterations in cardiac function and aortic pressure. Responses were also elicited by chemical stimulation in specific loci of these ganglia. The probability of eliciting a cardiovascular response by stimulating loci in a stellate ganglion increased with increasing postnatal age.

The effects of N-methyl-D-aspartate antagonism on the inspiratory activities of developing animals.

In developing kittens, antagonism of N-methyl-D-aspartate receptors by systemic injections of MK-801 produced: (a) blockage of the inspiratory off-switch, prolonging phrenic and hypoglossal discharges; (b) age-dependent changes of sympathetic inspiratory discharges, elimination of inspiratory-related discharges in animals less than or equal to 36 days old and prolongation of these discharges in older animals; (c) suppression of high-frequency oscillations in phrenic activities.