453 results about "Mr angiography" patented technology

A method and system for co-registration of angiography data and intra vascular ultrasound (IVUS) data is disclosed. A vessel branch is detected in an angiogram image. A sequence of IVUS images is received from an IVUS transducer while the IVUS transducer is being pulled back through the vessel branch. A fluoroscopic image sequence is received while the IVUS transducer is being pulled back through the vessel branch. The IVUS transducer and a guiding catheter tip are detected in each frame of the fluoroscopic image sequence. The IVUS transducer detected in each frame of the fluoroscopic image sequence is mapped to a respective location in the detected vessel branch of the angiogram image. Each of the IVUS images is registered to a respective location in the detected vessel branch of the angiogram image based on the mapped location of the IVUS transducer detected in a corresponding frame of the fluoroscopic image sequence.

A method of and system for performing intravenous tomographic digital angiography imaging which combines the principles of intravenous digital angiography with those of cone-beam volume tomography for generating a direct, unambiguous and accurate 3-D reconstruction of stenosis and other irregularities and malformations from 2-D cone-beam tomography projections is disclosed in which several different data acquisition geometries, such as a circle-plus-arc data acquisition geometry, may be utilized to provide a complete set of data so that an exact 3-D reconstruction is obtained. Only a single IV contrast injection with a short breathhold by the patient is needed for use with a volume CT scanner which uses a cone-beam x-ray source and a 2-D detector for fast volume scanning in order to provide true 3-D descriptions of vascular anatomy with more than 0.5 lp/mm isotropic resolution in the x, y and z directions is utilized in which one set of cone-beam projections is acquired while rotating the x-ray tube and detector on the CT gantry and then another set of projections is acquired while tilting the gantry by a small angle. The projection data is preweighted and the partial derivatives of the preweighted projection data are calculated. Those calculated partial derivatives are rebinned to the first derivative of the Radon transform, for both the circular orbit data and the arc orbit data. The second partial derivative of the Radon transform is then calculated and then the reconstructed 3-D images are obtained by backprojecting using the inverse Radon transform.

A system provides a single composite image including multiple medical images of a portion of patient anatomy acquired using corresponding multiple different types of imaging device. A display processor generates data representing a single composite display image including, a first image area showing a first image of a portion of patient anatomy acquired using a first type of imaging device, a second image area showing a second image of the portion of patient anatomy acquired using a second type of imaging device different to the first type. The first and second image areas include first and second markers respectively. The first and second markers identify an estimated location of the same corresponding anatomical position in the portion of patient anatomy in the first and second images respectively. A user interface enables a user to move at least one of, (a) the first marker in the first image and (b) the second marker in the second image, to correct the estimated location so the first and second markers identify the same corresponding anatomical position in the portion of patient anatomy.

In part, the invention relates to processing, tracking and registering angiography images and elements in such images relative to images from an intravascular imaging modality such as, for example, optical coherence tomography (OCT). Registration between such imaging modalities is facilitated by tracking of a marker of the intravascular imaging probe performed on the angiography images obtained during a pullback. Further, detecting and tracking vessel centerlines is used to perform a continuous registration between OCT and angiography images in one embodiment.

A technique for detecting and localising vascular occlusions in the brain of a patient is presented. The technique uses volumetric angiographic data of the brain. A mid-sagittal plane and/or lines is/are identified within the set of angiographic data. Optionally, the asymmetry of the hemispheres is measured, thereby obtaining an initial indication of whether an occlusion might be present. The angiographic data is mapped to pre-existing atlas of blood supply territories, thereby obtaining the portion of the angiographic data corresponding to each of the blood supply territories. For each territory (including any sub-territories), the asymmetry of the corresponding portion of the angiographic data about the mid-sagittal plane/lines is measured, thereby detecting any of the blood supply territory including an occlusion. The angiographic data for any such territory is displayed by a three-dimensional imaging technique.

A technique is provided for automatically generating a bone mask in CTA angiography. In accordance with the technique, an image data set may be pre-processed to accomplish a variety of function, such as removal of image data associated with the table, partitioning the volume into regionally consistent sub-volumes, computing structures edges based on gradients, and/or calculating seed points for subsequent region growing. The pre-processed data may then be automatically segmented for bone and vascular structure. The automatic vascular segmentation may be accomplished using constrained region growing in which the constraints are dynamically updated based upon local statistics of the image data. The vascular structure may be subtracted from the bone structure to generate a bone mask. The bone mask may in turn be subtracted from the image data set to generate a bone-free CTA volume for reconstruction of volume renderings.

An apparatus and method for detecting, tracking and registering a device (218) within a tubular organ (210) of a subject. The devices include guide wire (216) tip or therapeutic devices, and the detection and tracking uses fluoroscopic images taken prior to or during a catheterization operation. The devices are fused with images or projections of models depicting tile tubular organs. Tile method and apparatus are used for treating chronic total occlusion or near total occlusion situations, by navigating a driller along the tubular organ (210) proximally to the occlusion point, in areas which are-not viewable in an angiogram, and optionally enabling the penetration of the occlusion in a preferred area.

Methods of acquiring magnetic resonance imaging (MRI) data for angiography. The present invention includes novel magnetization preparation schemes where the navigator and fat saturation pulses are executed in steady state after the preparatory pulses in order to minimize the delay between the magnetization preparation and the image echoes. The present invention also provides for improved methods of contrast-enhanced MRI where data are collected along non-linear trajectories through k-space and may also involve novel view ordering. In addition, the present methods employ novel motion corrections that minimize motion artifacts. The present invention further provides novel methods of self-calibrated sensitivity-encoded parallel imaging that allow for accurate and rapid scanning of subjects.

The invention relates to a method for high-resolution display of vessel implants in angiographic images, featuring the steps: recording at least two images of an object-catheter combination including catheter markers with a medical imaging method; detection of an region of interest created in the form of an area between the balloon markers which completely contains the object to be registered for each recorded image; coarse registration of the region of interest images by registration of the respective pairs of balloon markers of all recorded images; fine registration of the region of interest image content/of the region of interest image by registration of the region of interest content; and arithmetic averaging across the fine-registered images.

An integrated catheter system for performing angiography on a human patient, the integrated catheter system consisting of an angiographic catheter onto which a thin-walled sheath is co-axially mounted. The angiographic catheter having an essentially straight and elongated proximal section in the form of a cylindrical shaft that is surrounded for less than one-half of its length by the thin-walled sheath that has an outer diameter that is less than 0.25 mm greater than the outside diameter of the angiography catheter. The strength to prevent buckling of the thin-walled sheath being provided by the shaft of the angiographic catheter. The integrated catheter system also being ideal for the placement of stents using small diameter stent delivery systems such as the stent-on-a-wire system.

Methods for improved acquisition and processing of optical coherence tomography (OCT) angiography data are presented. One embodiment involves improving the acquisition of the data by evaluating the quality of different portions of the data to identify sections having non-uniform acquisition parameters or non-uniformities due to opacities in the eye such as floaters. The identified sections can then be brought to the attention of the user or automatically reacquired. In another embodiment, segmentation of layers in the retina includes both structural and flow information derived from motion contrast processing. In a further embodiment, the health of the eye is evaluating by comparing a metric reflecting the density of vessels at a particular location in the eye determined by OCT angiography to a database of values calculated on normal eyes.

Methods and systems to analyze soft tissue or vasculature in a subject, form images with enhanced soft tissue contrast, determine blood flow parameters in soft tissue or vasculature, and to aid in the diagnosis of disease using thermoacoustic methods. Pulsed electromagnetic energy is administered to tissue to excite a thermoacoustic signal in the soft tissue or vasculature. An acoustic receiver or receiver array is coupled to a subject to detect and record the thermoacoustic signals produced. Thermoacoustic data are acquired after administration of a physiologically-tolerable tracer or contrast agent. The acquired data may be analyzed to produce images of the soft tissue and vasculature (angiogram), to determine blood flow parameters, and/or to diagnose disease in a subject.

A system and method for imaging a desired region of the circulatory system uses the subtraction of data from two acquisitions using substantially different RF pulses and/or pulse sequence timing parameters. In one or both data sets, the longitudinal magnetization of spins within a selected imaging volume has been altered by the application of one or more RF preparatory (prep) pulses. The prep is applied in such a way that subtraction eliminates signals from static background spins, such as fat, while maintaining the signal intensity of intravascular spins.

An improved ophthalmic imaging instrument including a wavefront sensor-based adaptive optical subsystem that measures phase aberrations in reflections derived from light produced by an imaging light source and compensates for such phase aberrations when capturing images of reflections derived from light produced by the same imaging light source. The high-resolution image data captured by the improved ophthalmic imaging instrument can be used to assist in detection and diagnosis (such as color imaging, fluorescein angiography, indocyanine green angiography) of abnormalities and disease in the human eye and treatment (including pre-surgery preparation and computer-assisted eye surgery such as laser refractive surgery) of abnormalities and disease in the human eye.

A method to visualize, display, analyze and quantify angiography, perfusion, and the change in angiography and perfusion in real time, is provided. This method captures image data sequences from indocyanine green near infra-red fluorescence imaging used in a variety of surgical procedure applications, where angiography and perfusion are critical for intraoperative decisions.

The device is provided with a laser (1) for exciting the fluorescent imaging agent which emits radiation at a wavelength that causes any of the agent located within the vasculature or tissue of interest (3) irradiated thereby to emit radiation of a particular wavelength. Advantageously, a camera capable of obtaining multiple images over a period of time, such as a CCD camera (2) may be used to capture the emissions from the imaging agent. A band-pass filter (6) prevents the capture of radiation other than that emitted by the imaging agent. A distance sensor (9) incorporates a visual display (9a) providing feedback to the physician saying that the laser be located at a distance from the vessel of interest that is optimal for the capture of high quality images.

Methods for quantitative perfusion analysis for embolotherapy are presented. The method quantitatively measures blood flow changes based on angiographic information. The method may provide potential evaluation of optimal embolization endpoints in vascular vessels. The method may be used in various applications such as transcatheter arterial chemoembolization (TACE), or other medical procedures that affect blow flow within bodily tissues. The method is applicable towards treatment of tumors in liver, kidney, brain, and other organs.

Disclosed herein is a medical imaging technique that uses a fluorinated nanoparticle contrast agent for imaging of an interior portion of a body. The fluorinated nanoparticles preferably comprise nontargeted intravascular fluorocarbon or perfluorocarbon nanoparticles. The interior body portion may be a patient's vasculature, and the medical imaging is preferably noninvasive MR angiography, which may encompass (either for 2D imaging or 3D imaging) MR coronary angiography, MR carotid angiography, MR peripheral angiography, MR cerebral angiography, MR arterial angiography, and MR venous angiography. Coils tuned to match to the ¹⁹F signal can be used, or dual tuned coils for ¹⁹F and ¹H imaging can be used. Clinical field strengths (e.g. 1.5 T) and clinical doses may be used while still providing effective images.

Multiple volumes that are to be aligned to form a single volume are processed. The system and method use an equalization step, a edge detection step and a correlation step to determine the overlapping positions between the first volume and the second volume of a volume pair having a maximum correlation value, and the best alignment of the first volume and the second volume of the volume pair is determined by the correlation value. A coarse correlation step using lower resolution volumes can be performed first followed by a fine correlation step using higher resolution images to save processing time. Initial preprocessing steps such as volume shearing can be performed. Equalization involves equalizing voxel size and edge detection can be performed using a Canny edge detector.

In a method and processing device for a magnetic resonance tomography apparatus, with which a test bolus measurement is conducted for a subsequent angiography measurement using contrast agent, a test bolus pop-up is displayed in an interactive graphic user interface, and a time curve of at least the arterial contrast agent concentration is automatically determined from the test bolus measurement and presented in the test bolus pop-up, for time planning of the subsequent angiography measurement.

In a magnetic resonance angiography method with flow-compensated and flow-sensitive imaging and a magnetic resonance apparatus for implementing such a method, a first MR data set of the examination region is acquired with an imaging sequence in which vessels in the examination region are shown with high signal intensity, a second MR data set of the examination region with an imaging sequence in which the vessels in the examination region are shown with low signal intensity, and the angiographic magnetic resonance image is calculated in a processor by taking the difference of the first and second data set. The first data set is acquired with an imaging sequence with reduced flow sensitivity and the second data set is acquired with an imaging sequence with an increased flow sensitivity compared to the initial imaging sequence.

The present invention includes a method and apparatus to perform rapid multi-slice MR imaging without ECG gating or requiring breath-holding that is capable of renal profusion analysis and angiographic screening. An ungated interleaved pulse sequence is applied in rapid succession, followed by a delay interval. The ungated interleaved pulse sequence is repeatedly played out with the predefined delay interval between each application of the pulse sequence. The resulting images provide not only a series of temporal phases of contrast-enhanced blood uptake for renal profusion analysis, but also provide enough dynamic range to include angiographic screening of the renal arteries.

A method and system for detecting lymph nodes in multiple complementary magnetic resonance (MR) sequences is disclosed. Anatomical landmarks, such as blood vessels, are extracted in a first MR sequence, such as an MR angiography (MRA) image. A search area is defined in at least one second MR sequence, such as a T1 weighted VIBE image, based on the anatomical landmarks extracted the first MR sequence. Lymph nodes are then detected in the search area of the second MR sequence. The lymph nodes can be detected by segmenting the search area into homogenous regions and determining whether each region is a lymph node using feature analysis.