Dentsply Sirona Inc.

Sirona Dental Systems Gmbh

Siemens Healthineers Ag

Stefan Wundrak

Mario Zeller

Stephan Biber

Andreas Greiser

Volker Rasche

Matthias Gebhardt

Lars Lauer

Kai Lindenberg

Edgar Müller

Johannes Ulrici

Jörg Rothard

Sebastian Dennert

Susanne Maur

Florian Odoj

Tobias Wichmann

Marco Geissner

Titus Lanz

A method of x-ray projection geometry calibration in x-ray cone beam computed tomography, including: at least one step (S) of obtaining two-dimensional x-ray images or a sinogram of at least a part of an object, generated through relatively rotating around the object a detector and an x-ray source projecting x-rays towards the detector; further including: at least one step (S) of detecting in the two dimensional x-ray images or the sinogram at least one feature of the object by using a trained artificial intelligence algorithm; and at least one step of creating, based on the detection, calibration information which defines the geometry of the x-ray projection.

Method of calibrating x-ray projection geometry in x-ray cone beam computed tomography

Described is a method for detecting and displaying the movement of a temporomandibular joint which connects a lower jaw and an upper jaw by magnetic resonance imaging. A marker is secured to the lower jaw, a marker movement curve is generated using magnetic resonance imaging measurement data sets during a first measurement interval, during which the lower jaw is moved relative to the upper jaw, and a point which corresponds to a first position of the lower jaw relative to the upper jaw is ascertained on the movement curve. An image data set is generated during a second measurement interval, during which the temporomandibular joint is not moved, and a first model, which represents at least one part of the upper jaw and/or a temporal bone part that comprises the temporomandibular joint socket, and a second model, which represents at least one part of the lower jaw, are ascertained therefrom. A movement curve of the second model relative to the first model is calculated and displayed using the marker movement curve.

Method for detecting the movement of a temporomandibular joint

Disclosed herein is a method for generating an MRI image in which a radial or spiral k-chamber path with a constant angular increment Psi is used to take an MRI image, the angular increment Psi being in the angular range of between 5-55 degrees or being in the corresponding supplementary angle Psi' and is selected according to the formula Psi=pi/(N+1/(M+tau&#x2212;1)). Alternatively, for an angular increment Psi which deviates from the angle increment of the optimal distribution of n radial profiles Psi=180&#xb0;/n, the minimum scanning efficiency of the angular increment Psi for n&#x3e;21 profiles is greater than 0.95, the angular increment Psi is in an angular range of 5&#xb0; to less than 68.7537&#xb0;, in particular between 5-55 degrees or in the corresponding supplementary angle Psi&#x2032;. Compared to the arrangement of the radial or spiral profile using the golden angle of 111.24&#xb0;, the angle increments calculated according to the above formula lead to lower eddy current artifacts, for example during the use of a b-SSFP-pulse sequence.

Method for generating a radial or spiral MRT image

The invention relates to a method for capturing a three-dimensional x-ray image () of an object () by means of an x-ray system () comprising an x-ray source (), an x-ray detector () and a shutter matrix (), the shutter matrix () having a plurality of shutter elements (), the x-ray absorption properties of which are controllable. In the first method step, at least one region () to be captured of the object () is defined, wherein settings are planned for the individual shutter elements () of the shutter matrix () for different rotary positions (), taking into account the defined area () to be captured. Then, a plurality of two-dimensional x-ray images is captured from the planned rotary positions () during at least one partial rotation () using the planned settings of the shutter elements (), wherein the overall three-dimensional x-ray image () of the area () to be captured is generated from the individual two-dimensional x-ray images.

Method for capturing a three-dimensional x-ray image

Disclosed is a method for producing magnetic resonance tomography images (B) of at least one phase of a cyclic movement, comprising the method steps: production of raw data sets (r, . . . , rx) of the cyclic movement during a recording period (T) having radial or almost radial k-space part trajectories (k, . . . , kx); reconstruction of a series of intermediate images (z, . . . , zy), each from at least one raw data set (r, . . . , rx) with high time resolution at least for each region (region of interest, ROI) of the raw data sets (r, . . . , rx); calculation of a distance matrix (D) from the series of intermediate images (z, . . . , zy), wherein each matrix element (D) corresponds to the distance of a first intermediate image (z, . . . , zy) of the series to the first or a further intermediate image (z, . . . , zy) of the series; fitting of functions (vi, . . . , vz) to structures forming in the distance matrix (D) by means of an active contour method and reconstruction of at least one image (B) from the raw data sets (r, . . . , rx), said raw data sets corresponding to intersection (S) of the fitted curves (v, . . . , vz) with a line of the distance matrix (D).

Method for producing magnet resonance tomography recordings of cyclic movement

The invention relates to a method for checking tooth positions, wherein an initial three-dimensional volume exposure () of teeth () to be checked is implemented, wherein the position and orientation of the teeth () to be checked are determined based on the initial volume exposure (); wherein the teeth to be checked are natural teeth () comprised of tooth stumps () and tooth roots () and/or are artificial teeth comprised of artificial tooth stumps and implants; wherein the positional relationship and orientation of the tooth stumps () relative to the tooth roots () and/or to the implants are determined in particular. For checking, a first optical surface monitoring exposure () of the teeth () is implemented, wherein using the positional relationship thus determined the position and orientation of the tooth roots () and/or of the implants relative to one another and/or relative to a jawbone () are determined based on the position of the surfaces () of the tooth stumps () from the optical surface monitoring exposure ().

Method for checking tooth positions

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Gronau, Germany

Stefan Wundrak