Siemens Aktiengesellschaft

Sandra Martin

Stefan Böhm

Tong Fang

Yunqiang Chen

Peter Durlak

Ti-chiun Chang

Stefan Boehm

Ralph Wössner

The invention relates to a method for noise suppression in medical images comprising steps of measuring the gradient field strength of an image pixel and selecting a suitable filter mask for noise suppression as a function of the gradient field strength, with the value of the gradient field strength being compared with a predetermined threshold value. The method is repeated when an additional image pixel is selected. A decision is made per read-in image pixel as to which type of filter mask is used for filtering. A selection can be made between filter masks of different sizes or isotropic or anisotropic or directional filter masks. The decision is based on the measured gradient field strength of the respective pixel. The use of different filter masks allows the signal-to-noise ratio to be improved, without distorting structures like edges for instance and without generating artificial structures in homogenous noise regions.

Method and device for noise suppression in medical images

A method and system for intelligent digital subtraction is disclosed. The method and system for intelligent digital subtraction can be used in a roadmap application for a coronary intervention. A mask image is obtained with vessels highlighted by contrast media. A guide wire is inserted into the vessels, and a guide wire image is obtained. A direct subtraction image is generated from the guide wire image and the mask image. A reduced noise subtraction image is generated based on mutual image information between the subtraction image and the guide wire image and mutual image information between the subtraction image and the mask image.

Method and system for intelligent digital subtraction

A method for setting a control variable of a filter for noise reduction in medical images is provided. Image data of the medical images is classified into at least one noise region and at least one structure region. A variance measurement is performed either for all the image pixels or a subset of them to determine the edge thicknesses. A histogram is generated from the edge thicknesses. The maximum of the histogram is determined and a Gaussian curve is fitted to the histogram. A threshold value for noise and structure is determined as a function of the standard deviation of the Gaussian curve. The noise and structure are measured in the regions. The standard noise and structure deviations are determined and compared. The control variable is setup as a function of the comparison of noise and structure. The invention can be used for reduction of temporal noise in bandpass images.

Method for setting at least one control variable of a filter for noise reduction in medical images

A method and system for correcting butting artifacts in x-ray images is disclosed. In order to correct a butting artifact in an x-ray image, a butting artifact region in the x-ray image is normalized. Multiple intensity shift estimators are calculated for each pixel of each line of the butting artifact. Confidence intervals are calculated for each intensity shift estimator. A multiple hypothesis hidden Markov model (MH-HMM) is formulated based on the intensity shift operators and confidence measures subject to a smoothness constraint, and the MH-HMM is solved to determine intensity shift values for each pixel. A corrected image is generated by adjusting the intensity of each pixel of the butting artifact based on the intensity shift value for that pixel.

Method and system for correcting butting artifacts in X-ray images

The present invention relates to a method for image reproduction, in particular for single or serial medical exposures, whereby one or more main images are reproduced on a display device. The method is characterized in that additional or interim images are generated using image interpolation prior to image reproduction from the one or more main images and in that additional image noise which varies from image to image is applied to the one or more main images and the additional or interim images, said image noise being generated by a noise generator, and image reproduction taking place by displaying in chronological order the one or more main images and additional or interim images to which the additional image noise has been applied. The method in particular improves the visual image impression in the case of fluoroscopic X-ray image exposures, without having to increase the applied X-ray dose.

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Herzogenaurauch, Germany

Sandra Martin