WO2002036011A1 - Method and apparatus for 3d-rotational x-ray imaging - Google Patents
Method and apparatus for 3d-rotational x-ray imaging Download PDFInfo
- Publication number
- WO2002036011A1 WO2002036011A1 PCT/EP2001/012079 EP0112079W WO0236011A1 WO 2002036011 A1 WO2002036011 A1 WO 2002036011A1 EP 0112079 W EP0112079 W EP 0112079W WO 0236011 A1 WO0236011 A1 WO 0236011A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- ray
- reconstruction
- images
- ray imaging
- imaging method
- Prior art date
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
- A61B6/54—Control of apparatus or devices for radiation diagnosis
- A61B6/541—Control of apparatus or devices for radiation diagnosis involving acquisition triggered by a physiological signal
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
- A61B6/48—Diagnostic techniques
- A61B6/481—Diagnostic techniques involving the use of contrast agents
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
- A61B6/50—Clinical applications
- A61B6/504—Clinical applications involving diagnosis of blood vessels, e.g. by angiography
Definitions
- the present invention relates to an X-ray imaging method comprising forming a set of 2-dimensional X-ray images of an object to be examined, for example the coronary vascular system of a patient, by means of a scan rotation of an X-ray source around said object over a run length, said X-ray images being acquired at predetermined characteristic time moments in cardiac cycle of the object and a reconstruction of a 3 -dimensional volume thereof.
- the invention further relates to a 3D-rotational X-ray apparatus for applying this method, the apparatus comprising a circular C-arm with a drive, the C-arm accommodating an X-ray source and an X-ray image pick-up device and being rotatable over an angle of substantially 180° around its center, triggering means for triggering the X-ray images at predetermined characteristic time moments in the cardiac cycle of the object and means for processing the images obtained to reconstruct a 3 -dimensional volume of the object.
- a 3 -dimensional volume of an object can be derived from a number of 2- dimensional computer tomograms by means of a CT-apparatus.
- the obtained 3-dimensional volume is related to the X-ray images; an association of corresponding projection images of this volume with the X-ray images results in a series of superposition images, which reproduces the two anatomic structures in geometrically correct association.
- information inherent to CT-measuring methods, e.g. information about tumors, is combined with typically X-ray information, e.g. information about blood vessels.
- a similar set of X-ray images can be obtained by using an X-ray apparatus with a rotatable source around its isocenter.
- conventional X-ray apparata are equipped with a C-arm, the technical details of such a construction falling within the scope of general knowledge of a person skilled in the art of X-ray imaging.
- a moving object such as a beating heart or more specifically the coronary vascular system of a beating heart of a human or animal, f ⁇ lle4 with a contrast medium
- a C-arm rotation speed in the X-ray apparatus of about 30°/s (degrees per second) or a scan duration or run length of about 6 s.
- During each run images are obtained for only certain angle areas. To cover the whole angle area of 180° several runs are necessary, the starting angle of each run relative to the cardiac cycle being adjusted by triggering the start of the run with a certain phase within the cardiac cycle.
- the images obtained can be used for a reconstruction of a 3- dimensional volume.
- a movement of the heart contributes to artefacts in the reconstructed image.
- a heart rate of 60 beats per minute and a framerate of for example 25 images per second during a scan movement over 180° during each heart beat 25 images are obtained and with 5 images in each specific phase of the cardiac cycle, 6 times 5 images are obtained, or, in other words, during each scan 5 times 6 corresponding X-ray images of a quasi-stationary heart can be obtained, which can be used for reconstruction of a 3 -dimensional volume.
- Problems of the known method are the necessity to correlate the different sub-runs in order to produce the 180° run as well as poor quality of the reconstructed image.
- the method as described in the opening paragraph is characterized in that the run length of the scan rotation over substantially 180° is at least 15 s and preferably about 20 s. Contrary to the present tendency to increase the C-arm rotation speed, it has been found that the above method can be improved by a slower rotational scanning speed. With a run length of about 20 s, i.e. a C-arm rotation speed of substantially 10°/s, and with the above parameters, during each scan about 5 times 20 corresponding X- ray images of a quasi-stationary heart can be obtained. Thus, by reducing the speed of the rotation of the X-ray source around the object more X-ray images corresponding to the same phase in the cardiac cycle are acquired. This leads to reduced noise in the resulting reconstructed 3-dimentional volume.
- a further embodiment of the X-ray imaging method according to the invention is characterized in that before reconstruction, images obtained at predetermined corresponding characteristic time moments in successive cardiac cycles are correlated with each other. This technical measure is based on the insight that each phase in the spectrum of cardiac activity in general represents the same spatial orientation and geometry of the heart muscle. Thus by correlating the X-ray images corresponding to the same phase of the cardiac activity, for example by known mathematical algorithms, one can further reduce noise in the final reconstruction of the 3-dimentional volume.
- a further embodiment of the X-ray imaging method according to the invention is characterized in that the characteristic time moments substantially correspond to R-peaks of the cardiac cycle. This technical measure provides the possibility to acquire images of the quasi-stationary heart, when the cardiac muscle is relaxed, thus reducing the image reconstruction noise due to the movement of the cardiac muscle.
- the methods of ECG- triggering are known and present no technical difficulty for those skilled in the art.
- a further embodiment of the X-ray imaging method according to the invention is characterized in that before a reconstruction, images obtained at neighbouring time moments in a predetermined characteristic time interval of a cardiac cycle are correlated with each other.
- This technical measure is based on the insight that if one determines a certain time interval around a characteristic moment in the ECG spectrum, for example around the R-peak, the movement of the heart muscle within this time interval has taken place to a such small degree that the X-ray images acquired within this predetermined time interval can be used for the image reconstruction.
- This technical measure provides the net noise reduction as the minor spatial movements or deformations of the heart muscle are compensated by the total number of the useful X-ray images contributing to the final dataset.
- the invention also relates to a 3D-rotational X-ray apparatus for applying the above method.
- a 3D-rotational X-ray apparatus for applying the above method.
- Such is an apparatus is already described in the opening paragraph and is, in accordance with the invention, further characterized in that the drive of the C-arm is adjusted to a run length of a scan rotation over substantially 180° which is at least 15 s and preferably about 20 s.
- Fig. 1 shows diagrammatically an X-ray imaging apparatus, in which the method according to the invention can be applied;
- Fig. 2 shows a cardiac cycle and preferred data acquisition times.
- the imaging apparatus of fig. 1 serves to form two-dimensional X-ray images of an object to be examined, particularly a periodically moving object such as the heart and the coronary vascular system of the heart of a patient, from which two-dimensional images via reconstruction a 3 -dimensional volume of the object can be obtained.
- the imaging apparatus 1 includes a circular C-arm 10 which is mounted on a (only partly shown) stand 11.
- the C-arm can be rotated over an angle of for example 180° around its center in the direction of the double arrow 20 by means of a motor drive (not shown in the figure).
- the C-arm 10 accommodates an X-ray source 12 and an X-ray image pick-up device 13, which are aligned relative to each other in such a manner that an X-ray image can be formed of a volume to be examined around said center.
- a plurality of X-ray images can thus be formed.
- This plurality of X-ray images shows the volume to be examined from different angular positions (some of which are denoted by dashed lines) of the image- forming system 12, 13.
- the X-ray image pick-up device 13 may be an X-ray image intensifier whereto a television chain is connected whose output signals are digitized by an analogue-to-digital converter 14 and stored in a memory 15 so that the overall X-ray image series ( ...Dn, Dj, D; +1 , Di +2 , ...) will have been stored at the end of the examination.
- These X- ray images can be processed by known reconstruction methods in an image processing unit 16 to obtain the 3 -dimensional volume to be examined. This volume or projections or cross sections thereof can be displayed on a monitor 18.
- the various components of the imaging apparatus 1 are controlled by means of a control unit 17.
- Fig. 2 is a diagram showing the substantially periodic cardiac cycles H and preferred data acquisition time intervals during end diastole ED on an ECG scale.
- a heart is relatively stationary during the end diastole time interval.
- the drive of the C-arm 10 is able or adjusted to perform a scan with a run length over 180° of at least 15 s and preferably about 20 s.
- a heart rate of 60 beats per second and 25 images per second and a run length of about 20 s i.e. a C-arm rotation speed of substantially 10°/s, during each scan about 5 times 20 corresponding non-moving X-ray images are obtained so that an improved reconstruction of the 3 -dimensional volume will be possible.
Abstract
An X-ray imaging method comprises forming 2-dimensional X-ray images of an object to be examined, for example the coronary vascular system of a patient, and reconstruction of a 3-dimensional volume thereof. With a relatively long run length of a scan rotation over substantially 180° of at least 15 sec. and preferably about 20 sec. A sufficient number of images is obtained to perform a more accurate volume reconstruction. This reconstruction method may be combined with existing modelling techniques.
Description
METHOD AND APPARATUS FOR 3D-ROTATIONAL X-RAY IMAGING
The present invention relates to an X-ray imaging method comprising forming a set of 2-dimensional X-ray images of an object to be examined, for example the coronary vascular system of a patient, by means of a scan rotation of an X-ray source around said object over a run length, said X-ray images being acquired at predetermined characteristic time moments in cardiac cycle of the object and a reconstruction of a 3 -dimensional volume thereof. The invention further relates to a 3D-rotational X-ray apparatus for applying this method, the apparatus comprising a circular C-arm with a drive, the C-arm accommodating an X-ray source and an X-ray image pick-up device and being rotatable over an angle of substantially 180° around its center, triggering means for triggering the X-ray images at predetermined characteristic time moments in the cardiac cycle of the object and means for processing the images obtained to reconstruct a 3 -dimensional volume of the object.
Such a method and apparatus are well known, e.g. from US-A-5, 852,646. In said document a 3 -dimensional volume of an object can be derived from a number of 2- dimensional computer tomograms by means of a CT-apparatus. The obtained 3-dimensional volume is related to the X-ray images; an association of corresponding projection images of this volume with the X-ray images results in a series of superposition images, which reproduces the two anatomic structures in geometrically correct association. In such a way information, inherent to CT-measuring methods, e.g. information about tumors, is combined with typically X-ray information, e.g. information about blood vessels.
In general, a similar set of X-ray images can be obtained by using an X-ray apparatus with a rotatable source around its isocenter. To enable such rotations conventional X-ray apparata are equipped with a C-arm, the technical details of such a construction falling within the scope of general knowledge of a person skilled in the art of X-ray imaging. When a method as described in the opening paragraph is applied to a moving object, such as a beating heart or more specifically the coronary vascular system of a beating heart of a human or animal, fιlle4 with a contrast medium, it is often standard practice to use a C-arm rotation speed in the X-ray apparatus of about 30°/s (degrees per second) or a scan duration or run
length of about 6 s. During each run images are obtained for only certain angle areas. To cover the whole angle area of 180° several runs are necessary, the starting angle of each run relative to the cardiac cycle being adjusted by triggering the start of the run with a certain phase within the cardiac cycle. The images obtained can be used for a reconstruction of a 3- dimensional volume. During this process a movement of the heart contributes to artefacts in the reconstructed image. With a heart rate of 60 beats per minute and a framerate of for example 25 images per second during a scan movement over 180°, during each hart beat 25 images are obtained and with 5 images in each specific phase of the cardiac cycle, 6 times 5 images are obtained, or, in other words, during each scan 5 times 6 corresponding X-ray images of a quasi-stationary heart can be obtained, which can be used for reconstruction of a 3 -dimensional volume. Problems of the known method are the necessity to correlate the different sub-runs in order to produce the 180° run as well as poor quality of the reconstructed image.
It is an object of the invention to provide a method where the above problems are solved. According to the invention, the method as described in the opening paragraph is characterized in that the run length of the scan rotation over substantially 180° is at least 15 s and preferably about 20 s. Contrary to the present tendency to increase the C-arm rotation speed, it has been found that the above method can be improved by a slower rotational scanning speed. With a run length of about 20 s, i.e. a C-arm rotation speed of substantially 10°/s, and with the above parameters, during each scan about 5 times 20 corresponding X- ray images of a quasi-stationary heart can be obtained. Thus, by reducing the speed of the rotation of the X-ray source around the object more X-ray images corresponding to the same phase in the cardiac cycle are acquired. This leads to reduced noise in the resulting reconstructed 3-dimentional volume.
A further embodiment of the X-ray imaging method according to the invention is characterized in that before reconstruction, images obtained at predetermined corresponding characteristic time moments in successive cardiac cycles are correlated with each other. This technical measure is based on the insight that each phase in the spectrum of cardiac activity in general represents the same spatial orientation and geometry of the heart muscle. Thus by correlating the X-ray images corresponding to the same phase of the cardiac activity, for example by known mathematical algorithms, one can further reduce noise in the final reconstruction of the 3-dimentional volume.
A further embodiment of the X-ray imaging method according to the invention is characterized in that the characteristic time moments substantially correspond to R-peaks of the cardiac cycle. This technical measure provides the possibility to acquire images of the quasi-stationary heart, when the cardiac muscle is relaxed, thus reducing the image reconstruction noise due to the movement of the cardiac muscle. The methods of ECG- triggering are known and present no technical difficulty for those skilled in the art.
A further embodiment of the X-ray imaging method according to the invention is characterized in that before a reconstruction, images obtained at neighbouring time moments in a predetermined characteristic time interval of a cardiac cycle are correlated with each other. This technical measure is based on the insight that if one determines a certain time interval around a characteristic moment in the ECG spectrum, for example around the R-peak, the movement of the heart muscle within this time interval has taken place to a such small degree that the X-ray images acquired within this predetermined time interval can be used for the image reconstruction. This technical measure provides the net noise reduction as the minor spatial movements or deformations of the heart muscle are compensated by the total number of the useful X-ray images contributing to the final dataset. Furthermore, it is still possible to correlate measurements at corresponding time moments of successive cardiac cycles with each other and, in case a reconstruction of a diminished quality is obtained, to combine the reconstruction with existing modelling techniques.
As already said, the invention also relates to a 3D-rotational X-ray apparatus for applying the above method. Such is an apparatus is already described in the opening paragraph and is, in accordance with the invention, further characterized in that the drive of the C-arm is adjusted to a run length of a scan rotation over substantially 180° which is at least 15 s and preferably about 20 s.
These and other aspects of the invention will be apparent from and elucidated with reference to the drawing and the embodiment described hereinafter. In the drawing:
Fig. 1 shows diagrammatically an X-ray imaging apparatus, in which the method according to the invention can be applied; and
Fig. 2 shows a cardiac cycle and preferred data acquisition times.
The imaging apparatus of fig. 1 serves to form two-dimensional X-ray images of an object to be examined, particularly a periodically moving object such as the heart and the coronary vascular system of the heart of a patient, from which two-dimensional images via reconstruction a 3 -dimensional volume of the object can be obtained.
The imaging apparatus 1 includes a circular C-arm 10 which is mounted on a (only partly shown) stand 11. The C-arm can be rotated over an angle of for example 180° around its center in the direction of the double arrow 20 by means of a motor drive (not shown in the figure). The C-arm 10 accommodates an X-ray source 12 and an X-ray image pick-up device 13, which are aligned relative to each other in such a manner that an X-ray image can be formed of a volume to be examined around said center. A plurality of X-ray images can thus be formed. This plurality of X-ray images shows the volume to be examined from different angular positions (some of which are denoted by dashed lines) of the image- forming system 12, 13. The X-ray image pick-up device 13 may be an X-ray image intensifier whereto a television chain is connected whose output signals are digitized by an analogue-to-digital converter 14 and stored in a memory 15 so that the overall X-ray image series ( ...Dn, Dj, D;+1, Di+2, ...) will have been stored at the end of the examination. These X- ray images can be processed by known reconstruction methods in an image processing unit 16 to obtain the 3 -dimensional volume to be examined. This volume or projections or cross sections thereof can be displayed on a monitor 18. The various components of the imaging apparatus 1 are controlled by means of a control unit 17.
Fig. 2 is a diagram showing the substantially periodic cardiac cycles H and preferred data acquisition time intervals during end diastole ED on an ECG scale. A heart is relatively stationary during the end diastole time interval.
According to the invention, the drive of the C-arm 10 is able or adjusted to perform a scan with a run length over 180° of at least 15 s and preferably about 20 s. With a heart rate of 60 beats per second and 25 images per second and a run length of about 20 s, i.e. a C-arm rotation speed of substantially 10°/s, during each scan about 5 times 20 corresponding non-moving X-ray images are obtained so that an improved reconstruction of the 3 -dimensional volume will be possible.
The present invention is not restricted to the embodiment described with reference to the accompanying drawing, but also relates to modifications thereof as far as such modifications fall within the scope of the following claims. So, it is possible to reduce the number of measuring points in the end diastole time intervals or to reduce the number of corresponding measuring points in successive cardiac cycles. Although such a reduction
results in a reconstruction of less quality, the negative effect thereof may be compensated by combination of the reconstruction method with existing modelling techniques. Of course, also in the preferred embodiment with a large number of measuring points in each diastole time interval, reconstruction may be combined with modelling techniques.
Claims
1. An X-ray imaging method comprising forming a set of 2-dimensional X-ray images (18) of an object to be examined, for example the coronary vascular system of a patient, by means of a scan rotation of an X- ray source (12) around said object over a run length (20), said X-ray images (3) being acquired at predetermined characteristic time moments in cardiac cycle (ED) of the object and reconstruction of a 3 -dimensional volume thereof, characterized in that the run length (20) of the scan rotation over substantially 180° is at least 15 s and preferably about 20 s.
2. An X-ray imaging method according to claim 1 , characterized in that, before reconstruction, images obtained at predetermined corresponding characteristic time moments in successive cardiac cycles are correlated with each other.
3. An X-ray imaging method according to claim 2, characterized in that the characteristic time moments substantially correspond to R-peaks of the cardiac cycle.
4. An X-ray imaging method according to claim 1 , characterized in that, before a reconstruction, images obtained at predetermined neighbouring time moments in a predetermined characteristic time interval of a cardiac cycle are correlated with each other.
5. An X-ray imaging method according to any one of the preceding claims, characterized in that the reconstruction is combined with modelling techniques.
6. 3D-rotational X-ray apparatus (1) for applying the method according to claim 1, comprising a circular C-arm (10) with a drive, the C-arm accommodating an X-ray source (12) and an X-ray image pick-up device (13) and being rotatable over an angle of substantially 180° around its center by means of said drive, triggering means for triggering the X-ray images at predetermined characteristic time moments in the cardiac cycle of the object, and means for processing the images obtained to reconstruct a 3 -dimensional volume of the object, characterized in that the drive of the C-arm (10) is adjusted to a run length of a scan rotation over substantially 180° which is at least 15 s and preferably about 20 s.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE60132004T DE60132004T2 (en) | 2000-11-02 | 2001-10-17 | METHOD AND DEVICE FOR 3D ROTATION X-RAY IMAGING |
EP01992530A EP1330186B1 (en) | 2000-11-02 | 2001-10-17 | Method and apparatus for 3d-rotational x-ray imaging |
JP2002538827A JP2004512130A (en) | 2000-11-02 | 2001-10-17 | Method and apparatus for three-dimensional rotary x-ray imaging |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP00203825.5 | 2000-11-02 | ||
EP00203825 | 2000-11-02 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2002036011A1 true WO2002036011A1 (en) | 2002-05-10 |
Family
ID=8172215
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2001/012079 WO2002036011A1 (en) | 2000-11-02 | 2001-10-17 | Method and apparatus for 3d-rotational x-ray imaging |
Country Status (5)
Country | Link |
---|---|
US (1) | US6959067B2 (en) |
EP (1) | EP1330186B1 (en) |
JP (1) | JP2004512130A (en) |
DE (1) | DE60132004T2 (en) |
WO (1) | WO2002036011A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2003101300A2 (en) * | 2002-06-04 | 2003-12-11 | Koninklijke Philips Electronics N.V. | Rotational angiography based hybrid 3-d reconstruction of coronary arterial structure |
US7426256B2 (en) | 2003-03-14 | 2008-09-16 | Koninklijke Philips Electronics N.V. | Motion-corrected three-dimensional volume imaging method |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE10119228A1 (en) * | 2001-04-19 | 2002-12-05 | Siemens Ag | Method for three-dimensional imaging of a moving examination object, in particular for cardiac imaging |
US7477928B2 (en) * | 2002-05-17 | 2009-01-13 | Ge Medical Systems Global Technology Company, Llc | Method and system for associating an EKG waveform with a CT image |
WO2004093684A1 (en) * | 2003-04-22 | 2004-11-04 | Philips Intellectual Property & Standards Gmbh | Apparatus for angiographic x-ray photography |
EP1639548B1 (en) | 2003-06-24 | 2008-10-08 | Philips Intellectual Property & Standards GmbH | Device to generate a three-dimensional image of a moved object |
US7782998B2 (en) * | 2004-12-21 | 2010-08-24 | General Electric Company | Method and apparatus for correcting motion in image reconstruction |
DE102005049603B4 (en) * | 2005-10-17 | 2010-09-16 | Siemens Ag | Method and device for imaging an organ |
DE102005061005A1 (en) * | 2005-12-20 | 2007-06-28 | Siemens Ag | Medical analysis device operating method, involves initiating activation of individual operations based on reference signal e.g. electrocardiogram signal, which represents actual motion state of organ which is to be imaged |
FR2924255A1 (en) * | 2007-11-27 | 2009-05-29 | Gen Electric | METHOD FOR PROCESSING RADIOGRAPHIC CARDIAC IMAGES FOR OBTAINING A SUBTRACT AND RECALLED IMAGE |
JP5305747B2 (en) * | 2008-06-17 | 2013-10-02 | キヤノン株式会社 | Radiation image capturing apparatus, driving method thereof, and program |
WO2010108146A2 (en) | 2009-03-20 | 2010-09-23 | Orthoscan Incorporated | Moveable imaging apparatus |
US8693634B2 (en) * | 2010-03-19 | 2014-04-08 | Hologic Inc | System and method for generating enhanced density distribution in a three dimensional model of a structure for use in skeletal assessment using a limited number of two-dimensional views |
US9125611B2 (en) | 2010-12-13 | 2015-09-08 | Orthoscan, Inc. | Mobile fluoroscopic imaging system |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5852646A (en) | 1996-05-21 | 1998-12-22 | U.S. Philips Corporation | X-ray imaging method |
DE19853964C1 (en) * | 1998-11-23 | 2000-05-18 | Siemens Ag | X-ray image recording for examination of rhythmically moving vessel or organ |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3178202B2 (en) | 1992-12-10 | 2001-06-18 | 松下電器産業株式会社 | Servo motor control parameter adjustment device and adjustment method |
DE19740214A1 (en) * | 1997-09-12 | 1999-04-01 | Siemens Ag | Computer tomography device with spiral scanning e.g. for examination of heart |
DE19746096A1 (en) * | 1997-10-17 | 1999-05-06 | Siemens Ag | X-ray device |
DE19746093C2 (en) * | 1997-10-17 | 2002-10-17 | Siemens Ag | C-arm X-ray device |
JPH11332273A (en) | 1998-05-15 | 1999-11-30 | Teikoku Electric Mfg Co Ltd | Operation monitoring apparatus for canned motor |
JP2000341985A (en) | 1999-05-27 | 2000-12-08 | Hitachi Ltd | Motor controller provided with failure diagnosis function |
-
2001
- 2001-10-17 EP EP01992530A patent/EP1330186B1/en not_active Expired - Lifetime
- 2001-10-17 WO PCT/EP2001/012079 patent/WO2002036011A1/en active IP Right Grant
- 2001-10-17 DE DE60132004T patent/DE60132004T2/en not_active Expired - Fee Related
- 2001-10-17 JP JP2002538827A patent/JP2004512130A/en active Pending
- 2001-11-30 US US10/022,383 patent/US6959067B2/en not_active Expired - Fee Related
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5852646A (en) | 1996-05-21 | 1998-12-22 | U.S. Philips Corporation | X-ray imaging method |
DE19853964C1 (en) * | 1998-11-23 | 2000-05-18 | Siemens Ag | X-ray image recording for examination of rhythmically moving vessel or organ |
Non-Patent Citations (1)
Title |
---|
MCKINNON G C ET AL: "Towards imaging the beating heart usefully with a conventional CT scanner", IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, IEEE INC. NEW YORK, US, vol. BME-28, no. 2, February 1981 (1981-02-01), pages 123 - 127, XP002164368, ISSN: 0018-9294 * |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2003101300A2 (en) * | 2002-06-04 | 2003-12-11 | Koninklijke Philips Electronics N.V. | Rotational angiography based hybrid 3-d reconstruction of coronary arterial structure |
WO2003101300A3 (en) * | 2002-06-04 | 2004-04-08 | Koninkl Philips Electronics Nv | Rotational angiography based hybrid 3-d reconstruction of coronary arterial structure |
US7180976B2 (en) | 2002-06-04 | 2007-02-20 | Koninklijke Philips Electronics N.V. | Rotational angiography based hybrid 3-D reconstruction of coronary arterial structure |
CN100443050C (en) * | 2002-06-04 | 2008-12-17 | 皇家飞利浦电子股份有限公司 | Rotational angiography based hybrid 3D reconstruction of coronary arterial structure |
US7426256B2 (en) | 2003-03-14 | 2008-09-16 | Koninklijke Philips Electronics N.V. | Motion-corrected three-dimensional volume imaging method |
Also Published As
Publication number | Publication date |
---|---|
EP1330186B1 (en) | 2007-12-19 |
JP2004512130A (en) | 2004-04-22 |
US20020126794A1 (en) | 2002-09-12 |
DE60132004D1 (en) | 2008-01-31 |
US6959067B2 (en) | 2005-10-25 |
EP1330186A1 (en) | 2003-07-30 |
DE60132004T2 (en) | 2008-12-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP4487095B2 (en) | Detection of coronary artery calcification using retrospective cardiac gating in an imaging system | |
EP0257922B1 (en) | System for dynamic scan at cyclic displacement | |
US6266553B1 (en) | Spiral scanning computed tomography apparatus, and method for operating same, for cardiac imaging | |
JP4436601B2 (en) | Method and apparatus for minimizing artifacts due to poor temporal alignment in gated CT images | |
JP4429677B2 (en) | CT imaging method for periodically moving organs | |
US7058440B2 (en) | Dynamic computed tomography imaging using positional state modeling | |
US5751782A (en) | X-ray computerized tomography apparatus and method for controlling the same | |
EP1088517B1 (en) | Method and apparatus for motion-free cardiac CT imaging | |
US6539074B1 (en) | Reconstruction of multislice tomographic images from four-dimensional data | |
US6879656B2 (en) | Method and apparatus for deriving motion information from projection data | |
US7570733B2 (en) | Step-and-shoot cardiac CT imaging | |
US6721386B2 (en) | Method and apparatus of cardiac CT imaging using ECG and mechanical motion signals | |
JP4712331B2 (en) | Organ imaging method, organ imaging apparatus, and computer-readable recording medium recording a computer program | |
JP4157302B2 (en) | X-ray CT system | |
US6959067B2 (en) | X-ray imaging method and a 3D-rotational X-ray apparatus for applying this method | |
JP2010510856A (en) | Reconstruction window adaptation in ECG gated computer tomography | |
JP2003204961A5 (en) | ||
US6956926B2 (en) | Method and apparatus for selecting a reconstruction projection set | |
JP4712956B2 (en) | A hybrid reconstruction method for high pitch multi-slice helical heart imaging | |
WO2004071301A1 (en) | X-ray ct device | |
JP2005040602A (en) | Inspection method for region performing periodic movement of subject and computed tomography device for performing this method | |
JP4007928B2 (en) | X-ray CT system | |
US20040019275A1 (en) | Method and apparatus for positioning a CT reconstruction window | |
Dhanantwari et al. | Correcting organ motion artifacts in x‐ray CT systems based on tracking of motion phase by the spatial overlap correlator. II. Experimental study | |
JPH0430834A (en) | X-ray ct apparatus |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
ENP | Entry into the national phase |
Ref country code: JP Ref document number: 2002 538827 Kind code of ref document: A Format of ref document f/p: F |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2001992530 Country of ref document: EP |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWP | Wipo information: published in national office |
Ref document number: 2001992530 Country of ref document: EP |
|
WWG | Wipo information: grant in national office |
Ref document number: 2001992530 Country of ref document: EP |