1) Patient motion is a common source of artifacts in MRI and can limit exam quality. Fast and effective motion correction provides better patient care and increases scanner efficiency and profitability.
2) Current main strategies are retrospective correction after scanning or "inline" correction during scanning using navigators. Navigators add minimal time but only work for periodic motion like breathing.
3) Emerging techniques like 3D-PACE can prospectively correct for unpredictable bulk motion like in brain scans, improving accuracy of techniques like fMRI. Further development may improve motion correction.
Assessment of Intrafraction Motion during real-time tracking in the treatment...Subrata Roy
In our experience, intrafraction motion for intracranial targets treated with fiducial free, frameless cranial SRS / SRT on CyberKnife with 6-D skull tracking, is within the acceptable range, and can be reliably detected and corrected. A PTV margin of 1 mm appears adequate to account for most of the intrafraction motion in this situation. However, significant intrafraction motion occurs during treatment delivery when mask based immobilization is used, and hence the same should be accounted for, in situations where intrafraction imaging is not being practiced. Owing to the highest level of precision, excellent automation, ease of treatment planning and delivery and avoidance of anaesthesia, CyberKnife Stereotactic Radiosurgery / Radiotherapy is highly recommended as an alternative to complex cranial neurosurgical procedures.
Automated Fetal Brain Segmentation from 2D MRI Slices for Motion Correction (...Kevin Keraudren
This document proposes an automated method for segmenting the fetal brain from 2D MRI slices that have been misaligned due to fetal motion. It combines fetal brain localization in each slice using Maximally Stable Extremal Regions (MSER) and Scale-Invariant Feature Transform (SIFT) features with a patch-based propagation and Conditional Random Field (CRF) to generate a segmentation mask for each slice. It then integrates this slice-by-slice segmentation with a motion correction process to iteratively refine the segmentation as the reconstruction proceeds. The method was tested on 66 datasets ranging from 22-39 weeks gestation and produced a motion corrected volume of diagnostic quality in 85% of cases while also generating a mean 93
Intuitionistic Fuzzy Clustering Based Segmentation of Spine MR ImagesIRJET Journal
This document presents a new method for segmenting spine MRI images using intuitionistic fuzzy clustering. Traditional fuzzy c-means clustering fails to account for spatial dependencies and noise in medical images. The proposed method applies anisotropic diffusion filtering for pre-processing to reduce noise. It then uses intuitionistic fuzzy clustering, which considers membership, non-membership, and hesitation values, to segment the vertebrae. Post-processing with morphological operations extracts and labels the vertebral bodies. Experimental results on 14 spine MRI images show the intuitionistic fuzzy clustering method achieves better segmentation performance than traditional fuzzy c-means, as measured by dice coefficient, Jaccard coefficient, precision, and recall.
Monitoring Motor Function in Children with Stroke Combining a Computer Game w...Virtual Sensei
It has been demonstrated that early diagnosis and development of effective rehabilitation strategies will substantially improve functional recovery in children with ischemic injury and that regular assessment of function and motor abilities is critical to implementation of correct rehabilitation interventions after a stroke. However, access to specialized care is limited for patients living in rural areas, particularly for pediatric ones. Our objective is to develop a computer-aided system to accurately monitor upper extremity motor function. This system is based on the combination of a “functional” test (video-game) that we have recently developed, with a prototyped sensor glove which measures angles of movement of wrist and elbow. Such a system would allow for self-evaluation and regular home-based monitoring of treatment efficacy and drive timely modification of clinical interventions.
Smart Noise Cancellation Processing: New Level of Clarity in Digital RadiographyCarestream
Smart Noise Cancellation (SNC) is a deep learning technique developed by Carestream Health to reduce noise in medical images while preserving fine detail. It uses a U-Net convolutional neural network trained on pairs of low-noise and simulated high-noise images. SNC predicts and subtracts a noise field from input images. Objective tests found SNC reduced noise by 2-4x while maintaining high-contrast sharpness and improving low-contrast detail detection. Subjective reader tests with radiologists found images processed with SNC were slightly to strongly preferable over traditional processing and had higher diagnostic capability ratings. SNC allows lowering radiation dose levels while maintaining image quality.
Mulligan Robust Optical Eye Detection During Head MovementKalle
Finding the eye(s) in an image is a critical rst step in a remote gaze-tracking system with a working volume large enough to encompass head movements occurring during normal user behavior. We briey review an optical method which exploits the retroreective properties of the eye, and present a novel method for combining difference images to reject motion artifacts. Best performance is obtained when a curvatur operator is used to enhance punctate features, and search is restricted to a neighborhood about the last known location. Optimal setting of the size of this neighborhood is aided by a statistical model of naturally-occurring head movements; we present head-movement statistics mined from a corpus of around 800 hours of video, collected in a team-performance experiment.
Digital Tomosynthesis: Theory of OperationCarestream
Digital Tomosynthesis (DT) is a new radiographic imaging technique that is revived from the nearly century-old traditional film-screen tomography. This rejuvenation is all made possible by the recent advances in high frame-rate, high-sensitivity flat-panel digital radiographic detector, rapid pulsed-exposure sequence-capable high-frequency x-ray generator, the widely available and low-cost computer GPU processing power, and the precision motion controls built in the digital radiography system hardware. Read the white paper.
Whitepaper: Image Quality Impact of SmartGrid Processing in Bedside Chest Ima...Carestream
Scattered radiation is known to degrade image quality in
diagnostic X-ray imaging. A new image processing tool, SmartGrid, has been developed that compensates for the effects of X-ray scatter in an image, and produces results comparable to those of a physical antiscatter grid. Read the white paper to learn more.
Assessment of Intrafraction Motion during real-time tracking in the treatment...Subrata Roy
In our experience, intrafraction motion for intracranial targets treated with fiducial free, frameless cranial SRS / SRT on CyberKnife with 6-D skull tracking, is within the acceptable range, and can be reliably detected and corrected. A PTV margin of 1 mm appears adequate to account for most of the intrafraction motion in this situation. However, significant intrafraction motion occurs during treatment delivery when mask based immobilization is used, and hence the same should be accounted for, in situations where intrafraction imaging is not being practiced. Owing to the highest level of precision, excellent automation, ease of treatment planning and delivery and avoidance of anaesthesia, CyberKnife Stereotactic Radiosurgery / Radiotherapy is highly recommended as an alternative to complex cranial neurosurgical procedures.
Automated Fetal Brain Segmentation from 2D MRI Slices for Motion Correction (...Kevin Keraudren
This document proposes an automated method for segmenting the fetal brain from 2D MRI slices that have been misaligned due to fetal motion. It combines fetal brain localization in each slice using Maximally Stable Extremal Regions (MSER) and Scale-Invariant Feature Transform (SIFT) features with a patch-based propagation and Conditional Random Field (CRF) to generate a segmentation mask for each slice. It then integrates this slice-by-slice segmentation with a motion correction process to iteratively refine the segmentation as the reconstruction proceeds. The method was tested on 66 datasets ranging from 22-39 weeks gestation and produced a motion corrected volume of diagnostic quality in 85% of cases while also generating a mean 93
Intuitionistic Fuzzy Clustering Based Segmentation of Spine MR ImagesIRJET Journal
This document presents a new method for segmenting spine MRI images using intuitionistic fuzzy clustering. Traditional fuzzy c-means clustering fails to account for spatial dependencies and noise in medical images. The proposed method applies anisotropic diffusion filtering for pre-processing to reduce noise. It then uses intuitionistic fuzzy clustering, which considers membership, non-membership, and hesitation values, to segment the vertebrae. Post-processing with morphological operations extracts and labels the vertebral bodies. Experimental results on 14 spine MRI images show the intuitionistic fuzzy clustering method achieves better segmentation performance than traditional fuzzy c-means, as measured by dice coefficient, Jaccard coefficient, precision, and recall.
Monitoring Motor Function in Children with Stroke Combining a Computer Game w...Virtual Sensei
It has been demonstrated that early diagnosis and development of effective rehabilitation strategies will substantially improve functional recovery in children with ischemic injury and that regular assessment of function and motor abilities is critical to implementation of correct rehabilitation interventions after a stroke. However, access to specialized care is limited for patients living in rural areas, particularly for pediatric ones. Our objective is to develop a computer-aided system to accurately monitor upper extremity motor function. This system is based on the combination of a “functional” test (video-game) that we have recently developed, with a prototyped sensor glove which measures angles of movement of wrist and elbow. Such a system would allow for self-evaluation and regular home-based monitoring of treatment efficacy and drive timely modification of clinical interventions.
Smart Noise Cancellation Processing: New Level of Clarity in Digital RadiographyCarestream
Smart Noise Cancellation (SNC) is a deep learning technique developed by Carestream Health to reduce noise in medical images while preserving fine detail. It uses a U-Net convolutional neural network trained on pairs of low-noise and simulated high-noise images. SNC predicts and subtracts a noise field from input images. Objective tests found SNC reduced noise by 2-4x while maintaining high-contrast sharpness and improving low-contrast detail detection. Subjective reader tests with radiologists found images processed with SNC were slightly to strongly preferable over traditional processing and had higher diagnostic capability ratings. SNC allows lowering radiation dose levels while maintaining image quality.
Mulligan Robust Optical Eye Detection During Head MovementKalle
Finding the eye(s) in an image is a critical rst step in a remote gaze-tracking system with a working volume large enough to encompass head movements occurring during normal user behavior. We briey review an optical method which exploits the retroreective properties of the eye, and present a novel method for combining difference images to reject motion artifacts. Best performance is obtained when a curvatur operator is used to enhance punctate features, and search is restricted to a neighborhood about the last known location. Optimal setting of the size of this neighborhood is aided by a statistical model of naturally-occurring head movements; we present head-movement statistics mined from a corpus of around 800 hours of video, collected in a team-performance experiment.
Digital Tomosynthesis: Theory of OperationCarestream
Digital Tomosynthesis (DT) is a new radiographic imaging technique that is revived from the nearly century-old traditional film-screen tomography. This rejuvenation is all made possible by the recent advances in high frame-rate, high-sensitivity flat-panel digital radiographic detector, rapid pulsed-exposure sequence-capable high-frequency x-ray generator, the widely available and low-cost computer GPU processing power, and the precision motion controls built in the digital radiography system hardware. Read the white paper.
Whitepaper: Image Quality Impact of SmartGrid Processing in Bedside Chest Ima...Carestream
Scattered radiation is known to degrade image quality in
diagnostic X-ray imaging. A new image processing tool, SmartGrid, has been developed that compensates for the effects of X-ray scatter in an image, and produces results comparable to those of a physical antiscatter grid. Read the white paper to learn more.
The most powerful diagnostic image processing software from Carestream Health, EVP Plus enables users to automatically render images without a priori knowledge of exam or body-part.
For more information, please visit us at: http://www.carestream.com/directview-evp-plus-software.html
Neurorobotics and Advances in rehabilitation engineeringBhaskarBorgohain4
Advances in robotics,mechatronics,cyborgs and disruptive technologies for heptics, brain machine interfaces and neurorobotics are bringing a sea change to the field of rehabilitation engineering. Carbon fibre cheetah blades, Bionic arms, c legs are helping the amputees to the extent that amputees can now run in competitive sports at the level of summer Olympics.
EVP Plus Software delivers state-of-the-art image processing for CR and DR sy...Carestream
Radiographic technologists expect a high degree of
automation and efficiency in the technology they use in their
daily workflow, which means they expect minimal interaction
with the technology’s modality software. At the same time,
radiologists also need the flexibility to specify their site’s
individualized diagnostic viewing preferences. The CARESTREAM DirectView EVP Plus Software successfully
overcomes this challenge for digital-projection radiography.
EVP Plus automatically processes and delivers diagnostic-quality DR and CR images to PACS, based on look preferences that can be uniquely specified by each site.
1) The document describes a real-time 3D MR acquisition technique for capturing respiratory motion during simultaneous PET-MR imaging to correct for motion in the PET reconstruction.
2) A fast 3D radial projection sequence was used with a 2-parameter golden angle scheme to continuously and uniformly sample k-space without repeating projections.
3) Image reconstruction of sliding window frames used sparse reconstruction to generate motion images, and 4D registration analyzed all frames to determine the 3D motion vector field.
The document discusses quality assurance procedures for a Tomotherapy unit used for cancer treatment. It describes the treatment planning and delivery process, as well as quality assurance checks performed daily by therapists and physicists to verify calibration, beam characteristics, and accuracy of patient plans and treatments. These include daily, monthly, and annual checks of the system using phantoms and dosimetry equipment to ensure safe and effective radiation therapy.
This document discusses high-field open MR imaging using the Altaire system. It provides background on open MR and notes that the Altaire achieves one of the highest field strengths for open MR at 0.7T. The Altaire incorporates noise reduction technology and advanced gradients to improve image quality comparable to closed MR systems. It utilizes a vertical quadrature solenoid coil design that increases SNR by 40% over other systems. Contributing authors and their institutions are listed.
This document discusses using through-time radial GRAPPA reconstruction to achieve high temporal and spatial resolution for real-time cardiac imaging. Radial acquisitions are more tolerant to undersampling than Cartesian, allowing higher acceleration. Through-time radial GRAPPA uses multiple calibration frames to calculate geometry-specific GRAPPA kernels for each missing k-space sample, improving over segmentation approaches. This allows reconstruction of images from highly accelerated radial data with temporal resolution under 50ms as recommended by SCMR, enabling assessment of cardiac function without breath-holds. Initial results show this technique can provide diagnostic quality real-time cardiac images.
Event recognition image & video segmentationeSAT Journals
Abstract This paper gives a clear look at the segmentation process at the basic level. Segmentation is done at multiple levels so that we will get different results. Segmentation of relative motion descriptors gives a clear picture about the segmentation done for a given input video. Relative motion computation and histograms incrementation are used to evaluate this approach. Also here we will give complete information about the related research which is done about how segmentation can be done for the both images and videos. Keywords: Image Segmentation, Video Segmentation.
Bone Suppression for Chest Radiographic ImagesCarestream
Learn about Carestream's Bone Suppression Software and how it's used to aid in the detection of lung diseases.
For more information on Carestream's software solutions, please visit http://carestream.com/software
Reconstruction of the upper human femur from microCT images and FEM(Post-grad...Katerina Stamou
The document describes a post-graduate thesis that aims to reconstruct the 3D structure of the upper femur from computed tomography images and analyze its mechanical properties using finite element meshes. It involves segmenting the CT images using algorithms in the Insight Toolkit to create a model of the bone that can then be discretized and have differential equations representing static loading conditions solved on it. The segmentation uses a region growing method implemented in 3D Slicer to isolate the bone from surrounding tissue.
Tube and Line and Pneumothorax Visualization SoftwareCarestream
Carestream has implemented companion views in its digital
radiography systems. A companion view is designed to
complement the standard processed radiographic image
delivered from the digital radiography capture modality to
PACS, to provide an additional rendering tailored for the visual
interpretation needed for a specific diagnostic or clinical
purpose. Two companion views are available in Carestream
products for chest radiography: one for the optimal
visualization of tubes and lines in chest radiographs
(CARESTREAM Tube & Line Visualization Software), and the
other for enhancing the conspicuity of a pneumothorax
(CARESTREAM Pneumothorax Visualization Software).
4D radiotherapy aims to adapt treatment plans based on organ and tumor motion over time. This requires 4D data management systems to record treatment delivery and portal images over time. Image processing tools like deformable registration and model-based segmentation can help automate identifying organ motion between 3D scans. Adaptive planning approaches could modify plans at intervals of multiple fractions, daily, or intra-fraction to account for changes. Determining if daily replanning is practical requires considering workload, data management, and the incremental clinical benefits versus costs.
Fuzzy Clustering Based Segmentation of Vertebrae in T1-Weighted Spinal MR Imagesijfls
The document summarizes a study that developed an automated method for segmenting vertebrae from T1-weighted spinal MRI images using fuzzy c-means clustering. The method first performs anisotropic diffusion filtering for pre-processing. It then applies fuzzy c-means clustering to segment the vertebrae. Various morphological operations are used as post-processing to extract and label the individual vertebrae. The method is compared to Otsu thresholding and K-means clustering. Validation using the Dice coefficient and Hausdorff distance measures showed the fuzzy clustering method provided more accurate segmentation of the vertebrae from the MR images.
There are three major complications of diabetes which lead to blindness. They are retinopathy, cataracts, and glaucoma among which diabetic retinopathy is considered as the most serious complication affecting the blood vessels in the retina. Diabetic retinopathy (DR) occurs when tiny vessels swell and leak fluid or abnormal new blood vessels grow hampering normal vision.
Diabetic retinopathy is a widespread problem of visual impairment. The abnormalities like microaneurysms, hemorrhages and exudates are the key symptoms which play an important role in diagnosis of diabetic retinopathy. Early detection of these abnormalities may prevent the blurred vision or vision loss due to diabetic retinopathy. Basically exudates are lipid lesions able to be seen in optical images. Exudates are categorized into hard exudates and soft exudates based on its appearance. Hard exudates come out as intense yellow regions and soft exudates have fuzzy manifestations. Automatic detection of exudates may aid ophthalmologists in diagnosis of diabetic retinopathy and its early treatment. Fig. 1 shows the key symptoms of diabetic retinopathy.
This document summarizes a new computer-aided detection method for intracranial aneurysms that enhances 3D images and highlights potential aneurysms. The method segments arteries from MRI images, determines artery centerlines, and assigns voxels to centerlines. It then colors the anatomical surface from cool to hot based on the change in distance from the centerline, signaling potential aneurysms. An evaluation of 8 subjects found the method detected all 9 true aneurysms with 3.875 false positives per subject on average. The structural information provided by the enhancements could help radiologists better diagnose and plan treatment for aneurysms.
IGRT (Image-Guided Radiotherapy) uses x-rays and scans before and during radiation therapy to more precisely target tumors and reduce radiation exposure to healthy tissues. IGRT allows doctors to detect and correct errors in patient positioning and account for changes in tumor size or position during treatment. This improves accuracy and allows higher radiation doses to tumors or reduced margins around tumors, lowering toxicity risks and improving patient outcomes and quality of life. While requiring additional resources, IGRT has become a standard part of radiation therapy by improving precision and reducing uncertainties.
INHIBITION AND SET-SHIFTING TASKS IN CENTRAL EXECUTIVE FUNCTION OF WORKING ME...sipij
Understanding of neuro-dynamics of a complex higher cognitive process, Working Memory (WM) is
challenging. In WM, information processing occurs through four subsystems: phonological loop, visual
sketch pad, memory buffer and central executive function (CEF). CEF plays a principal role in WM. In this
study, our objective was to understand the neurospatial correlates of CEF during inhibition and set-shifting
processes. Thirty healthy educated subjects were selected. Event-Related Potential (ERP) related to visual
inhibition and set-shifting task was collected using 32 channel EEG system. Activation of those ERPs
components was analyzed using amplitudes of positive and negative peaks. Experiment was controlled
using certain parametric constraints to judge behavior, based on average responses in order to establish
relationship between ERP and local area of brain activation and represented using standardized low
resolution brain electromagnetic tomography. The average score of correct responses was higher for
inhibition task (87.5%) as compared to set-shifting task (59.5%). The peak amplitude of neuronal activity
for inhibition task was lower compared to set-shifting task in fronto-parieto-central regions. Hence this
proposed paradigm and technique can be used to measure inhibition and set-shifting neuronal processes in
understanding pathological central executive functioning in patients with neuro-psychiatric disorders.
Paulin hansen.2011.gaze interaction from bedmrgazer
This document describes a low-cost gaze tracking system designed for bedbound people. The system uses off-the-shelf hardware including a video camera, projector, and computer running open-source gaze tracking software. A large image is projected on a wall in front of the bed to allow visibility for others in the room while freeing up space around the bedridden user. An experiment tested the system's accuracy and precision with 12 subjects in both seated and lying positions. Gaze tracking was found to be most accurate and precise when subjects were seated versus lying down, and in the bottom half of the projected image versus the top half. The system achieved sufficient accuracy for basic gaze-based interaction applications.
Abstract:
A technique for exudate detectionin fundus image is been presented in this paper. Due to diabetic retinopathy an abnormality is caused known as exudates.The loss of vision can be prevented by detecting the exudates as early as possible. The work mainly aims at detecting exudates which is present in the green channel of the RGB image by applying few preprocessing steps, DWT and feature extraction. The extracted features are fed to 3 different classifiers such as KNN, SVM and NN. Based on the classifier result if an exudate is present the extraction of exudate ROI is done based on canny edge detection followed by morphological operations. The severity of the exudates is established on the area of the detected exudate.
Keywords:Exudates, Fundus image, Diabetic retinopathy, DWT, KNN, SVM, NN, Canny edge detection, Morphological operations.
Treatment planning involves defining target volumes and organs at risk on imaging scans. Virtual simulation uses CT scans to delineate structures and localize the treatment isocenter. This allows improved volume definition compared to conventional simulation. Treatment planning optimization selects parameters like beam number, weighting, and modifiers to best conform the dose distribution to planning objectives while minimizing dose to organs at risk. Beam modifiers like wedges and compensators can be used to modify the dose distribution for target coverage and organ sparing.
This document discusses advances in neuroimaging techniques using MRI. It covers 4 basic steps in MRI including placing the patient in a magnet, sending and receiving radiofrequency pulses, and transforming signals into images. Improvements discussed include large field of view imaging using sliding tables, high field strength 3T imaging for improved resolution, efficient data processing techniques like parallel imaging, and improved pulse sequences. Specific sequences covered are fast spin echo, fluid attenuated inversion recovery, gradient echo imaging, steady state sequences, susceptibility weighted imaging, diffusion imaging, perfusion imaging, and magnetic resonance spectroscopy.
Steady-state free precession (SSFP) is a unique MRI sequence that uses both spin echo and gradient echo techniques. In SSFP, gradient echoes are acquired in each repetition time (TR) while maintaining coherence between excitations using balanced gradients. This results in a signal dependent on T1 and T2 properties. SSFP provides high signal-to-noise ratio and is used for cardiac imaging, flow imaging, T1/T2 mapping, and whole body imaging, but is sensitive to field inhomogeneities. Sensitivity encoding (SENSE) uses knowledge of multiple receiver coils' spatial sensitivities to unfold aliased signals and reduce scan time.
The most powerful diagnostic image processing software from Carestream Health, EVP Plus enables users to automatically render images without a priori knowledge of exam or body-part.
For more information, please visit us at: http://www.carestream.com/directview-evp-plus-software.html
Neurorobotics and Advances in rehabilitation engineeringBhaskarBorgohain4
Advances in robotics,mechatronics,cyborgs and disruptive technologies for heptics, brain machine interfaces and neurorobotics are bringing a sea change to the field of rehabilitation engineering. Carbon fibre cheetah blades, Bionic arms, c legs are helping the amputees to the extent that amputees can now run in competitive sports at the level of summer Olympics.
EVP Plus Software delivers state-of-the-art image processing for CR and DR sy...Carestream
Radiographic technologists expect a high degree of
automation and efficiency in the technology they use in their
daily workflow, which means they expect minimal interaction
with the technology’s modality software. At the same time,
radiologists also need the flexibility to specify their site’s
individualized diagnostic viewing preferences. The CARESTREAM DirectView EVP Plus Software successfully
overcomes this challenge for digital-projection radiography.
EVP Plus automatically processes and delivers diagnostic-quality DR and CR images to PACS, based on look preferences that can be uniquely specified by each site.
1) The document describes a real-time 3D MR acquisition technique for capturing respiratory motion during simultaneous PET-MR imaging to correct for motion in the PET reconstruction.
2) A fast 3D radial projection sequence was used with a 2-parameter golden angle scheme to continuously and uniformly sample k-space without repeating projections.
3) Image reconstruction of sliding window frames used sparse reconstruction to generate motion images, and 4D registration analyzed all frames to determine the 3D motion vector field.
The document discusses quality assurance procedures for a Tomotherapy unit used for cancer treatment. It describes the treatment planning and delivery process, as well as quality assurance checks performed daily by therapists and physicists to verify calibration, beam characteristics, and accuracy of patient plans and treatments. These include daily, monthly, and annual checks of the system using phantoms and dosimetry equipment to ensure safe and effective radiation therapy.
This document discusses high-field open MR imaging using the Altaire system. It provides background on open MR and notes that the Altaire achieves one of the highest field strengths for open MR at 0.7T. The Altaire incorporates noise reduction technology and advanced gradients to improve image quality comparable to closed MR systems. It utilizes a vertical quadrature solenoid coil design that increases SNR by 40% over other systems. Contributing authors and their institutions are listed.
This document discusses using through-time radial GRAPPA reconstruction to achieve high temporal and spatial resolution for real-time cardiac imaging. Radial acquisitions are more tolerant to undersampling than Cartesian, allowing higher acceleration. Through-time radial GRAPPA uses multiple calibration frames to calculate geometry-specific GRAPPA kernels for each missing k-space sample, improving over segmentation approaches. This allows reconstruction of images from highly accelerated radial data with temporal resolution under 50ms as recommended by SCMR, enabling assessment of cardiac function without breath-holds. Initial results show this technique can provide diagnostic quality real-time cardiac images.
Event recognition image & video segmentationeSAT Journals
Abstract This paper gives a clear look at the segmentation process at the basic level. Segmentation is done at multiple levels so that we will get different results. Segmentation of relative motion descriptors gives a clear picture about the segmentation done for a given input video. Relative motion computation and histograms incrementation are used to evaluate this approach. Also here we will give complete information about the related research which is done about how segmentation can be done for the both images and videos. Keywords: Image Segmentation, Video Segmentation.
Bone Suppression for Chest Radiographic ImagesCarestream
Learn about Carestream's Bone Suppression Software and how it's used to aid in the detection of lung diseases.
For more information on Carestream's software solutions, please visit http://carestream.com/software
Reconstruction of the upper human femur from microCT images and FEM(Post-grad...Katerina Stamou
The document describes a post-graduate thesis that aims to reconstruct the 3D structure of the upper femur from computed tomography images and analyze its mechanical properties using finite element meshes. It involves segmenting the CT images using algorithms in the Insight Toolkit to create a model of the bone that can then be discretized and have differential equations representing static loading conditions solved on it. The segmentation uses a region growing method implemented in 3D Slicer to isolate the bone from surrounding tissue.
Tube and Line and Pneumothorax Visualization SoftwareCarestream
Carestream has implemented companion views in its digital
radiography systems. A companion view is designed to
complement the standard processed radiographic image
delivered from the digital radiography capture modality to
PACS, to provide an additional rendering tailored for the visual
interpretation needed for a specific diagnostic or clinical
purpose. Two companion views are available in Carestream
products for chest radiography: one for the optimal
visualization of tubes and lines in chest radiographs
(CARESTREAM Tube & Line Visualization Software), and the
other for enhancing the conspicuity of a pneumothorax
(CARESTREAM Pneumothorax Visualization Software).
4D radiotherapy aims to adapt treatment plans based on organ and tumor motion over time. This requires 4D data management systems to record treatment delivery and portal images over time. Image processing tools like deformable registration and model-based segmentation can help automate identifying organ motion between 3D scans. Adaptive planning approaches could modify plans at intervals of multiple fractions, daily, or intra-fraction to account for changes. Determining if daily replanning is practical requires considering workload, data management, and the incremental clinical benefits versus costs.
Fuzzy Clustering Based Segmentation of Vertebrae in T1-Weighted Spinal MR Imagesijfls
The document summarizes a study that developed an automated method for segmenting vertebrae from T1-weighted spinal MRI images using fuzzy c-means clustering. The method first performs anisotropic diffusion filtering for pre-processing. It then applies fuzzy c-means clustering to segment the vertebrae. Various morphological operations are used as post-processing to extract and label the individual vertebrae. The method is compared to Otsu thresholding and K-means clustering. Validation using the Dice coefficient and Hausdorff distance measures showed the fuzzy clustering method provided more accurate segmentation of the vertebrae from the MR images.
There are three major complications of diabetes which lead to blindness. They are retinopathy, cataracts, and glaucoma among which diabetic retinopathy is considered as the most serious complication affecting the blood vessels in the retina. Diabetic retinopathy (DR) occurs when tiny vessels swell and leak fluid or abnormal new blood vessels grow hampering normal vision.
Diabetic retinopathy is a widespread problem of visual impairment. The abnormalities like microaneurysms, hemorrhages and exudates are the key symptoms which play an important role in diagnosis of diabetic retinopathy. Early detection of these abnormalities may prevent the blurred vision or vision loss due to diabetic retinopathy. Basically exudates are lipid lesions able to be seen in optical images. Exudates are categorized into hard exudates and soft exudates based on its appearance. Hard exudates come out as intense yellow regions and soft exudates have fuzzy manifestations. Automatic detection of exudates may aid ophthalmologists in diagnosis of diabetic retinopathy and its early treatment. Fig. 1 shows the key symptoms of diabetic retinopathy.
This document summarizes a new computer-aided detection method for intracranial aneurysms that enhances 3D images and highlights potential aneurysms. The method segments arteries from MRI images, determines artery centerlines, and assigns voxels to centerlines. It then colors the anatomical surface from cool to hot based on the change in distance from the centerline, signaling potential aneurysms. An evaluation of 8 subjects found the method detected all 9 true aneurysms with 3.875 false positives per subject on average. The structural information provided by the enhancements could help radiologists better diagnose and plan treatment for aneurysms.
IGRT (Image-Guided Radiotherapy) uses x-rays and scans before and during radiation therapy to more precisely target tumors and reduce radiation exposure to healthy tissues. IGRT allows doctors to detect and correct errors in patient positioning and account for changes in tumor size or position during treatment. This improves accuracy and allows higher radiation doses to tumors or reduced margins around tumors, lowering toxicity risks and improving patient outcomes and quality of life. While requiring additional resources, IGRT has become a standard part of radiation therapy by improving precision and reducing uncertainties.
INHIBITION AND SET-SHIFTING TASKS IN CENTRAL EXECUTIVE FUNCTION OF WORKING ME...sipij
Understanding of neuro-dynamics of a complex higher cognitive process, Working Memory (WM) is
challenging. In WM, information processing occurs through four subsystems: phonological loop, visual
sketch pad, memory buffer and central executive function (CEF). CEF plays a principal role in WM. In this
study, our objective was to understand the neurospatial correlates of CEF during inhibition and set-shifting
processes. Thirty healthy educated subjects were selected. Event-Related Potential (ERP) related to visual
inhibition and set-shifting task was collected using 32 channel EEG system. Activation of those ERPs
components was analyzed using amplitudes of positive and negative peaks. Experiment was controlled
using certain parametric constraints to judge behavior, based on average responses in order to establish
relationship between ERP and local area of brain activation and represented using standardized low
resolution brain electromagnetic tomography. The average score of correct responses was higher for
inhibition task (87.5%) as compared to set-shifting task (59.5%). The peak amplitude of neuronal activity
for inhibition task was lower compared to set-shifting task in fronto-parieto-central regions. Hence this
proposed paradigm and technique can be used to measure inhibition and set-shifting neuronal processes in
understanding pathological central executive functioning in patients with neuro-psychiatric disorders.
Paulin hansen.2011.gaze interaction from bedmrgazer
This document describes a low-cost gaze tracking system designed for bedbound people. The system uses off-the-shelf hardware including a video camera, projector, and computer running open-source gaze tracking software. A large image is projected on a wall in front of the bed to allow visibility for others in the room while freeing up space around the bedridden user. An experiment tested the system's accuracy and precision with 12 subjects in both seated and lying positions. Gaze tracking was found to be most accurate and precise when subjects were seated versus lying down, and in the bottom half of the projected image versus the top half. The system achieved sufficient accuracy for basic gaze-based interaction applications.
Abstract:
A technique for exudate detectionin fundus image is been presented in this paper. Due to diabetic retinopathy an abnormality is caused known as exudates.The loss of vision can be prevented by detecting the exudates as early as possible. The work mainly aims at detecting exudates which is present in the green channel of the RGB image by applying few preprocessing steps, DWT and feature extraction. The extracted features are fed to 3 different classifiers such as KNN, SVM and NN. Based on the classifier result if an exudate is present the extraction of exudate ROI is done based on canny edge detection followed by morphological operations. The severity of the exudates is established on the area of the detected exudate.
Keywords:Exudates, Fundus image, Diabetic retinopathy, DWT, KNN, SVM, NN, Canny edge detection, Morphological operations.
Treatment planning involves defining target volumes and organs at risk on imaging scans. Virtual simulation uses CT scans to delineate structures and localize the treatment isocenter. This allows improved volume definition compared to conventional simulation. Treatment planning optimization selects parameters like beam number, weighting, and modifiers to best conform the dose distribution to planning objectives while minimizing dose to organs at risk. Beam modifiers like wedges and compensators can be used to modify the dose distribution for target coverage and organ sparing.
This document discusses advances in neuroimaging techniques using MRI. It covers 4 basic steps in MRI including placing the patient in a magnet, sending and receiving radiofrequency pulses, and transforming signals into images. Improvements discussed include large field of view imaging using sliding tables, high field strength 3T imaging for improved resolution, efficient data processing techniques like parallel imaging, and improved pulse sequences. Specific sequences covered are fast spin echo, fluid attenuated inversion recovery, gradient echo imaging, steady state sequences, susceptibility weighted imaging, diffusion imaging, perfusion imaging, and magnetic resonance spectroscopy.
Steady-state free precession (SSFP) is a unique MRI sequence that uses both spin echo and gradient echo techniques. In SSFP, gradient echoes are acquired in each repetition time (TR) while maintaining coherence between excitations using balanced gradients. This results in a signal dependent on T1 and T2 properties. SSFP provides high signal-to-noise ratio and is used for cardiac imaging, flow imaging, T1/T2 mapping, and whole body imaging, but is sensitive to field inhomogeneities. Sensitivity encoding (SENSE) uses knowledge of multiple receiver coils' spatial sensitivities to unfold aliased signals and reduce scan time.
Role of medical imaging in management of arteriovenous fistula Dr. Muhammad B...Dr. Muhammad Bin Zulfiqar
This presentation is very helpful for vascular sergeons, interventional radiologists and sonographers that how to map Vasculature before construction of AV fistula for hemodialysis, how to check its patency, how to check its proper functioning ,to comment on its failure and decide when to reintervene.
Radiological approach to Congenital skeletal dysplasiaSachin Balutkar
This document provides an overview of skeletal dysplasias and their radiological diagnosis. It defines osteochondrodysplasias as abnormalities of bone and cartilage growth due to abnormal gene expression, and dysostoses as altered bone formation in the first 6 weeks of life with a fixed phenotype. International classifications of osteochondrodysplasias are described, along with imaging approaches for antenatal ultrasound and post-natal skeletal surveys. Specific skeletal dysplasias are then discussed in more detail based on their classification group, with a focus on characteristic radiological findings for each condition. The Radiological Electronic Atlas Of Malformation Syndromes And Skeletal Dysplasias (REAMS) is also introduced as an online
1. The document describes several medical cases with imaging findings and diagnoses. It discusses abnormalities seen on CT scans and x-rays indicating conditions like diffuse idiopathic skeletal hyperostosis, tuberculous spondylitis, leaking dermoid tumour, Takayasu arteritis, and advanced bronchial carcinoma.
2. Key findings mentioned include flowing osteophytes, ossification of the posterior longitudinal ligament, calcified psoas abscesses, hydronephrosis, widened mediastinum with sternotomy sutures, dissecting aneurysm of the aorta, occlusion of arteries, and diffuse mural thickening of the rectum and colon.
3. The document
Imaging in obstetrics & gynaecology (part 1- Gynaecological scans in benign c...drmcbansal
Ultrasonography is a type of medical imaging that uses high-frequency sound waves to visualize structures within the body. It is a non-invasive technique that provides real-time images and does not use radiation. Common applications of ultrasound in gynecology include evaluating the uterus, ovaries, and fallopian tubes. A transvaginal probe is often used to obtain detailed images of the pelvic organs. Normal ultrasound appearances of the ovaries include scattered antral follicles that develop during the menstrual cycle. Ovulation is identified by a decrease in size of the dominant follicle. The corpus luteum that forms after ovulation can be seen as a cyst or echogenic area on ultrasound.
Brain Image Fusion using DWT and Laplacian Pyramid Approach and Tumor Detecti...INFOGAIN PUBLICATION
Image fusion is the process of combining important information from two or more images into a single image. The resulting image will be more enhanced than any of the input pictures. The idea of combining multiple image modalities to furnish a single, more enhanced image is well established, special fusion methods have been proposed in literature. This paper is based on image fusion using laplacian pyramid and Discreet Wavelet Transform (DWT) methods. This system uses an easy and effective algorithm for multi-focus image fusion which uses fusion rules to create fused image. Subsequently, the fused image is obtained by applying inverse discreet wavelet transform. After fused image is obtained, watershed segmentation algorithm is applied to detect the tumor part in fused image.
This document reviews and classifies techniques for motion segmentation in computer vision. It discusses several categories of techniques, including image differencing, statistical approaches using maximum a posteriori probability, particle filtering and expectation maximization, wavelet-based methods, and optical flow. For each category, some example algorithms are described and their strengths and weaknesses are discussed. The document provides an overview of common challenges in motion segmentation and attributes to consider for algorithms.
iaetsd Image fusion of brain images using discrete wavelet transformIaetsd Iaetsd
1) The document discusses using discrete wavelet transform to fuse MRI and CT brain images. This allows physicians to view soft tissue details from MRI and bone details from CT in a single fused image.
2) Discrete wavelet transform decomposes images into different frequency bands, allowing salient features like edges to be separated. It is proposed to fuse MRI and CT brain images using discrete wavelet transform to reduce noise and computational load compared to other methods.
3) Fusing the images provides advantages for physicians by having both soft tissue and bone details in a single image, reducing storage costs compared to viewing images separately.
Analysis of Efficient Wavelet Based Volumetric Image CompressionCSCJournals
Recently, the wavelet transform has emerged as a cutting edge technology, within the field of image compression research. Telemedicine, among other things, involves storage and transmission of medical images, popularly known as teleradiology. Due to constraints on bandwidth and storage capacity, a medical image may be needed to be compressed before transmission/storage. This paper is focused on selecting the most appropriate wavelet transform for a given type of medical image compression. In this paper we have analysed the behaviour of different type of wavelet transforms with different type of medical images and identified the most appropriate wavelet transform that can perform optimum compression for a given type of medical image. To analyze the performance of the wavelet transform with the medical images at constant PSNR, we calculated SSIM and their respective percentage compression.
This document proposes a novel method for medical image denoising that combines contourlet thresholding, bilateral filtering, and non-local means filtering. Specifically, it introduces scaling factors to the universal threshold for wavelet and contourlet transforms. It then uses the contourlet-based thresholding as a pre-processing step before bilateral or non-local means filtering for denoising. Simulation results show the combined approach achieves better PSNR and perceptual quality than using bilateral or non-local means filtering alone.
ADAPTIVE, SCALABLE, TRANSFORMDOMAIN GLOBAL MOTION ESTIMATION FOR VIDEO STABIL...cscpconf
Video Stabilization, which is important for better analysis and user experience, is typically done through Global Motion Estimation (GME) and Compensation. GME can be done in image domain using many techniques or in Transform domain using the well-known Phase Correlation methods which relate motion to phase shift in the spectrum. While image domain methods are generally slower (due to dense vector field computations), they can do global as well as local motion estimation. Transform domain methods cannot normally do local motion, but are faster and more accurate on homogeneous images, and are resilient to even rapid illumination changes and large motion. However both these approaches can become very time consuming if one needs more accuracy and smoothness because of the nature of the tradeoff. We show here that wavelet transforms can be used in a novel way to achieve a very smooth stabilization along with a significant speedup in this Fourier domain computation without sacrificing accuracy. We
do this by adaptively selecting and combining motion computed on a specific pair of sub-bands using the wavelet interpolation capability. Our approach yields a smooth, scalable, fast and
adaptive algorithm (based on time requirement and recent motion history) to yield significantly better accuracy than a single level wavelet decomposition based approach.
This document is a final progress report for an fMRI study investigating individual differences in visual perception within low signal-to-noise environments. The study used a random dot motion task with varying coherence levels to evaluate brain activation patterns across 15 participants. Preliminary results found some variability between individuals in activated brain areas. Further analysis is needed to characterize differences between subjects and better understand individual abilities in visual signal detection.
1) The document presents a novel scheme for calculating Standardized Uptake Values (SUV) from PET scans using DICOM files without specialized application software.
2) SUV is a semi-quantitative measure used to analyze FDG-PET images in clinical practice, with a value above 2.5 often indicating malignant lesions.
3) The scheme calculates SUVmax, which is less affected by partial volume effects, and its results are compared to values from GE healthcare software, showing a significant correlation.
3D Spherical Harmonics Deformation Visualization of Intraoperative OrganIOSR Journals
This document provides a literature review of recent experiments on real-time 3D visualization of intraoperative organ deformations. It describes several techniques used for real-time 3D visualization, including 3D echocardiography, intraoperative MRI, intraoperative MRI at 3 Tesla, laparoscopic radiofrequency ablation of liver tumors, magneto-optic tracking, navigation in endoscopic soft tissue surgery, adaptive 4D imaging, radiofrequency ablation of liver tumors, and intraoperative fast 3D shape recovery. It provides details on the features, advantages, and disadvantages of each technique. The document concludes by introducing a new approach for real-time 3D visualization using spherical harmonics deformation modeling to reconstruct organ shapes from sparse surface samples
This document describes a low-cost 3D ultrasound system developed to image the brachial plexus for regional anesthesia procedures. The system uses two webcams and custom tracking hardware attached to an ultrasound probe to optically track its movement and reconstruct a 3D image from a series of 2D ultrasound images. Initial results demonstrated a proof of concept for generating a 3D image using freely available software, though processing was slow at 8 hours. Faster processing is expected once the software is compiled. The 3D ultrasound system has the potential to help physicians more accurately locate anatomy like the brachial plexus during regional anesthesia procedures.
Image restoration model with wavelet based fusionAlexander Decker
1. The document discusses various techniques for image restoration, which aims to recover a sharp original image from a degraded one using mathematical models of degradation and restoration.
2. It analyzes techniques like deconvolution using Lucy Richardson algorithm, Wiener filter, regularized filter, and blind image deconvolution on different image formats based on metrics like PSNR, MSE, and RMSE.
3. Previous studies have applied techniques like Wiener filtering, wavelet-based fusion, and iterative blind deconvolution for motion blur restoration and compared their performance.
Image processing techniques in nm 08,09Rutuja Solkar
Digital images in nuclear medicine consist of grids of pixels that represent discrete picture elements. Image processing techniques are used to analyze these images. Key techniques include:
1. Visualizing images by adjusting grayscale, color scale, and windowing.
2. Defining regions and volumes of interest to extract numerical data from tissues.
3. Co-registering images acquired at different times to compare changes in the same subject.
4. Creating time-activity curves from series of frames to analyze radiotracer uptake over time in regions of interest.
5. Smoothing images reduces noise but blurs details, while edge detection and segmentation identify boundaries and classify tissues.
Neuroendoscopy Adapter Module Development for Better Brain Tumor Image Visual...IJECEIAES
The issue of brain magnetic resonance image exploration together with classification receives a significant awareness in recent years. Indeed, various computer-aided-diagnosis solutions were suggested to support radiologist in decision-making. In this circumstance, adequate image classification is extremely required as it is the most common critical brain tumors which often develop from subdural hematoma cells, which might be common type in adults. In healthcare milieu, brain MRIs are intended for identification of tumor. In this regard, various computerized diagnosis systems were suggested to help medical professionals in clinical decision-making. As per recent problems, Neuroendoscopy is the gold standard intended for discovering brain tumors; nevertheless, typical Neuroendoscopy can certainly overlook ripped growths. Neuroendoscopy is a minimally-invasive surgical procedure in which the neurosurgeon removes the tumor through small holes in the skull or through the mouth or nose. Neuroendoscopy enables neurosurgeons to access areas of the brain that cannot be reached with traditional surgery to remove the tumor without cutting or harming other parts of the skull. We focused on finding out whether or not visual images of tumor ripped lesions ended up being much better by auto fluorescence image resolution as well as narrow-band image resolution graphic evaluation jointly with the latest neuroendoscopy technique. Also, within the last several years, pathology labs began to proceed in the direction of an entirely digital workflow, using the electronic slides currently being the key element of this technique. Besides lots of benefits regarding storage as well as exploring capabilities with the image information, among the benefits of electronic slides is that they can help the application of image analysis approaches which seek to develop quantitative attributes to assist pathologists in their work. However, systems also have some difficulties in execution and handling. Hence, such conventional method needs automation. We developed and employed to look for the targeted importance along with uncovering the best-focused graphic position by way of aliasing search method incorporated with new Neuroendoscopy Adapter Module (NAM) technique.
The document discusses techniques for magnetic resonance neurography (MRN). It describes various 2D and 3D pulse sequences that can be used for MRN, including T1-weighted, T2-weighted, STIR and SPAIR sequences. 3D sequences like SPACE are commonly used and provide isotropic images. The document highlights the benefits of different sequences for visualizing peripheral nerves and discusses interpretation considerations. It emphasizes the importance of fat suppression and resolution for accurate depiction of the smallest nerve structures.
This document discusses a hand gesture recognition system using electromyography (EMG) signals. EMG sensors on the forearm detect muscle signals which are preprocessed, analyzed in the frequency domain, and classified. Features like Fourier transforms, power spectra, and autoregressive coefficients are extracted from the signals. Various classification algorithms are tested and Naive Bayes achieves the highest accuracy of 95% for categorizing five different hand gestures.
Este documento describe un estudio sobre el uso de resonancia magnética no ecoplanar para diagnosticar colesteatoma. El estudio evaluó 8 pacientes con sospecha de colesteatoma mediante resonancia magnética no ecoplanar, cirugía y anatomía patológica. Los resultados mostraron que la resonancia magnética no ecoplanar confirmó correctamente el diagnóstico de colesteatoma en 6 de los casos y descartó el diagnóstico en 1 caso. La resonancia magnética no ecoplanar podría usarse para reducir el
El documento describe la anatomía y patologías del oído. Describe las tres partes principales del oído: externo, medio e interno. El oído externo incluye la aurícula, el meato auditivo externo y la membrana timpánica. El oído medio contiene los tres huesecillos auditivos y la cavidad timpánica. El oído interno alberga la cóclea, el vestíbulo y los canales semicirculares. También describe varias patologías comunes como el colesteatoma ad
This document provides information on several medical imaging topics and technologies:
- It highlights abstracts from the ECR 2014 conference focusing on adaptive diagnostics and how they can solve clinical challenges. Abstracts discuss the latest 3T MRI experience, a new metal artifact reduction algorithm, and lung subtraction versus dual energy CT.
- It also provides information on Toshiba's new products and technologies including the next generation Aquilion ONE CT scanner, planning for hybrid labs, dual energy CT applications, and dose reduction techniques for interventional procedures.
- Additional sections profile customer sites and applications of Toshiba ultrasound, CT, and MRI systems.
Dr. Punwani at University College London Hospital uses the Philips Ingenia 3.0T MRI for multi-parametric prostate and whole-body oncology exams. Multi-parametric MRI provides more information than standard anatomical imaging alone by including techniques like diffusion-weighted imaging, dynamic contrast-enhanced imaging, and spectroscopy. This additional data helps localize and characterize lesions, assisting in initial diagnosis and monitoring treatment effectiveness. The Ingenia's dS coils enable high-quality, whole-body multi-parametric MRI exams within a reasonable scan time.
This document discusses advanced neuroimaging solutions from Philips including high performance susceptibility weighted imaging, arterial spin labeling for non-contrast perfusion imaging, and high-end diffusion weighted imaging technologies. It provides information on visualization and analysis tools for multi-modality viewing as well as dedicated offerings for neuroscientists including high-end DTI, fMRI, and quality assurance tools. The document also highlights specific neuro imaging techniques such as diffusion tensor imaging with up to 128 directions and 32 b-values, fat-free diffusion weighted imaging, and comprehensive tools and quality assurance for fMRI.
The new Siemens SOMATOM Force CT scanner, installed at the University Medical Center Mannheim in Germany, enables more individualized patient diagnostics and contributions to personalized medicine. It is twice as fast as previous Dual Source CT systems and allows for improved image quality. Radiologists believe the SOMATOM Force opens possibilities for value-based medicine by targeting the clinical outcomes of medical procedures and patient recovery. The consistency of quantitative data produced by the high-end CT system cannot be matched by other imaging modalities, making CT an accepted imaging biomarker.
This document summarizes experiences using dual energy CT (DECT) from experts in Germany, the Netherlands, and Japan. DECT provides additional clinical information compared to conventional CT. Experts in Munich are researching using single source DECT to quantify iodine uptake in lesions. Experts in Rotterdam are using dual source DECT in pediatric patients to assess heart and lung abnormalities without sedation. Experts in Japan find DECT useful for distinguishing thyroid cartilage from head and neck tumors to avoid overtreatment. DECT is becoming more widely used in clinical practice and research due to improved diagnostic capabilities.
1) The syngo.via system and CT Oncology Engine allow radiologist Catherine Radier to spend more time with patients by automating and streamlining tasks like lesion detection, data retrieval, and comparing scans over time.
2) For acute stroke patients, neuroradiologist Peter Schramm uses the CT Neuro Engine and syngo.via to quickly identify the ischemic core, tissue at risk of infarction (penumbra), and location of blood clots within 10 minutes to determine appropriate treatment like thrombolysis or clot retrieval.
3) Dynamic CT angiography applications in syngo.via help estimate clot size over time which is difficult to assess from single timepoint scans, aiding decisions
The Sainte-Marie Clinic in Osny, France was one of the first places to install the new SOMATOM Perspective CT scanner in early 2012. They have already examined around 800 patients for almost all types of pathologies. The medical team is satisfied with the scanner's diagnostic performance, speed of exams, and ability to reduce radiation doses by around 50% compared to their previous scanner. The easy workflow and quick exams are beneficial when imaging children and patients needing repetitive exams.
The article discusses advances in computed tomography (CT) for neuroimaging that enable both exceptional image quality and low radiation dose. It profiles Duke University Medical Center's use of Siemens CT equipment for neuroimaging. New techniques like CT perfusion, Neuro Best Contrast, and dual energy applications have changed the diagnostic approach. CT is now routinely used as the primary modality for evaluating acute neurological diseases before treatment to detect hemorrhages or other causes of symptoms like stroke. The low dose capabilities and high image quality of Siemens CT scanners are helping radiologists maximize diagnostic confidence.
This article discusses Siemens' efforts over the past two decades to reduce radiation dose in CT scans through technological innovations. It provides a timeline of important milestones in dose reduction, including the introduction of CARE Dose4D in 1994, ECG-pulsing in 1999, the Definition Flash scanner in 2008, and Iterative Reconstruction in Image Space (IRIS) in 2009. The article highlights feedback from physicians on the clinical benefits of CARE Dose4D, the Adaptive Dose Shield, the Definition Flash, and IRIS, which together have reduced radiation exposure to a fraction of original levels while maintaining image quality. Siemens' goal is to continuously improve dose reduction and expand the clinical applications of CT
This article discusses the clinical experience and performance of the SOMATOM Definition Flash Dual Source CT scanner. Initial results from early testing at the University of Erlangen-Nuremberg show that the scanner is exceeding expectations. It can perform a thorax scan in under 1 second and a cardiac scan in 270 ms with a radiation dose of under 1 mSv. The extremely fast scan speed provides motion-free images and expands clinical applications to include patients who cannot hold their breath. Early results also indicate potential for cardiac CT screening due to the very low radiation dose.
The article discusses the need for fast, high-quality and low-dose CT imaging in acute care and cardiology settings when diagnosing critical injuries. Two experts, Dr. Savvas Nicolaou from Vancouver General Hospital and Dr. Jörg Hausleiter from German Heart Center in Munich, emphasize the importance of CT for making timely diagnoses and treatment decisions. They expect the new Stellar Detector technology to provide improved image quality while further reducing radiation dose. The detector aims to balance diagnostic image quality with lower patient radiation, especially important for younger patients. Its ability to produce high-resolution images at high speed could help physicians make critical decisions within the "golden hour" window for treating conditions like stroke.
The article discusses the need for fast, high-quality and low-dose CT imaging in acute care and cardiology settings when diagnosing critical injuries. Two experts, Dr. Savvas Nicolaou from Vancouver General Hospital and Dr. Jörg Hausleiter from German Heart Center Munich, emphasize the importance of CT for timely diagnosis and treatment decisions. They expect the new Stellar Detector technology to provide improved image quality while further reducing radiation dose. The detector aims to balance diagnostic image quality with low patient exposure, especially important for young patients and repeated scans. Its high spatial and temporal resolution could benefit applications like trauma, stroke and coronary imaging where seconds matter.
This document is an issue of the SOMATOM Sessions magazine from Siemens Healthcare. The main stories discussed are:
1. Iterative reconstruction is becoming mainstream for computed tomography as new techniques like SAFIRE have accelerated the reconstruction process.
2. A new protocol called FAST CARE has significantly reduced scan times for cardiac CT exams.
3. The software syngo.via allows physicians to view CT, MRI, and PET images simultaneously for a complete picture of the patient's condition.
The new FAST CARE software from Siemens aims to standardize and simplify CT scans through several innovations. It guides users intuitively through the entire scan process from planning to reconstruction. This reduces workload and potential for errors. FAST CARE also facilitates dose reduction through tools like iterative reconstruction and automatic selection of optimal scan parameters. Dr. Michael Lell expects FAST CARE to save time and improve efficiency, allowing clinics to examine more patients with fewer resources. He is also hopeful the automatic coupling of contrast injection and scanning can reduce staffing needs. Overall, FAST CARE makes CT scans safer, more reproducible and effective for both patients and clinicians.
The new FAST CARE software from Siemens aims to standardize and simplify CT scans through several innovations. It guides users intuitively through the entire scan process from planning to reconstruction. This reduces workload and potential for errors. FAST CARE also facilitates dose reduction through tools like iterative reconstruction and automatic selection of optimal scan parameters. Dr. Michael Lell expects FAST CARE to save time and improve efficiency, allowing clinics to examine more patients with fewer resources. He is particularly interested in the potential for automatic contrast injection to reduce staffing needs. Overall, FAST CARE enhances productivity while maintaining diagnostic quality and safety.
The document discusses developing optimal protocols for simultaneous MR-PET examinations. Initial experience with the first MR-PET system for clinical use showed promise for anatomically focused and whole-body exams. For focused exams, MR provided high-resolution anatomical maps to localize metabolic information from PET. Whole-body MR-PET allowed metabolic bone imaging with improved localization compared to PET-CT. Continued experience will help optimize protocols to maximize benefits from the multi-parametric data provided by the combined MR-PET system.
This document summarizes techniques for pediatric MRI. It notes that children require specialized skills and equipment due to differences from adults in disease types, sensitivity to radiation, and physiology/behavior. Longer scan times are often needed for neonates due to tissue properties. Techniques to improve image quality include using restore pulses and optimized protocols. Safety is a primary concern, especially for heating risks in neonates/infants. Patient cooperation challenges can be addressed through explanation, mock scans, distraction techniques, and anesthesia if needed. Overall the goal is high quality diagnostic images while minimizing distress.
The document discusses abdominal MRI on the new MAGNETOM Prisma 3T scanner. It notes the advantages of 3T MRI include higher signal-to-noise ratio and contrast-to-noise ratio, allowing for improved spatial resolution and lesion detection. However, challenges at 3T include increased magnetic field inhomogeneities and susceptibility artifacts. The MAGNETOM Prisma addresses these challenges through technical advances, such as improved B0 and B1 field homogeneity which provide better image quality for liver imaging compared to standard 3T scanners. The article demonstrates examples of reduced distortion and improved diffusion-weighted imaging of the liver on MAGNETOM Prisma.
2. Motion Correction for MR Imaging
Kyle A. Salem, PhD
Motion Artifacts in a Clinical Setting or be scanned with another, less ideal, modality.
Patient motion is probably the most common cause Integrated Parallel Acquisition Techniques (iPAT)
of artifacts in today’s MR imaging. This can range significantly reduce scan times and are useful, but in
from physiological motion, such as respiratory or a few cases strategies for motion control are needed.
cardiac movement, to physical movement by the In the setting of the MR department, fast, effective
patient. Physical movement may be due to voluntary motion control provides better care, serves more
movements or involuntary movements as in patients (which increases revenue), and makes
Parkinsonism. Physiologic motion can be controlled scanning more efficient by eliminating repeat
by gating or in the sequence design, so it is really scanning (which could potentially increase profit).
the physical patient movement that creates the
Current Strategies for Motion Control
largest concern and will be addressed here.
Today, the most common strategy for handling
The reality is that patients are often in pain and may motion artifacts is to use retrospective motion
or may not be cooperative. Many times, the patient correction. These post-processing approaches use
for whom the results are most needed is also the a variety of algorithmic, iterative approaches applied
patient who can be the least cooperative. Beyond in the image domain as well as in k-space.1 While
that, the longer a patient spends in the scanner the they can be effective and are certainly applicable
more likely they are to become restless, agitated, or to any acquired image, once the data is corrupted
nervous, which again leads to motion in the images. by motion, you cannot recover ideal data. A better
strategy, as seen in some of the newer techniques
Patient Motion and the Clinical Exam
and research, is to perform the motion control
Since most exams in the chest and abdomen are
during the acquisition, or “inline”, so that the data
dominated by physiologic motion, the goal of most
is never corrupted.
motion correction algorithms is to produce ideal
images in the head or extremities. In the clinic a Navigators
typical head examination consists of T1, T2 Turbo The fastest “inline” method of controlling motion
Spin Echo (TSE), Dark-Fluid (FLAIR) inversion is the “navigator” technique, 1D-PACE (Prospective
recovery (IR), and possibly a diffusion scan (EPI or Acquisition Correction) to Siemens.2 This technique
TSE). Practical imaging times for these exams at only adds about 30 ms to your scan and is typically
1.5T are about 3 minutes, 2 minutes, 3 minutes, used for controlling physiologic motion, such as
and 1 minute, respectively. Notice that the sequences respiratory motion in cardiac or abdominal exams.
with the longest scan times are also those where It works by acquiring a single line of data from
the most motion artifact can occur, simply because a pencil-shaped volume that crosses the boundary
the patient has more time to move. So the diffusion of the diaphragm. This single line of data allows
scans, and to a lesser extent the T2 TSE sequences, the scanner, in real time, to know the exact position
are not as susceptible to patient motion since they of the diaphragm and trigger a scan only when
are also the fastest. the diaphragm is at the appropriate position. So
But motion is still a very real problem that requires misalignment is eliminated by only acquiring data
an efficient solution. Images that are corrupted by when the anatomy is in a specific location.
motion artifacts can be rendered unreadable. Many Siemens provides an enhancement to the traditional
sick patients are unable to cooperate long enough navigator technique that makes it more robust and
to be imaged without artifacts. Some are simply adds quality and reliability. The 2D-PACE technique
unable to complete an exam and must have the scan acquires a low resolution gradient echo image in
repeated, be called back for another appointment, approximately 100 ms. A low flip angle is used to
1
3. Figure 2: Finger tapping fMRI:
trained stimulus-correlated
1.5° rotation head motion. t-test:
3D spatial filter
& t-test:
Motion Correction: None ART 3D PACE
ensure that the magnetization is only minimally An alternative strategy is to use each acquired volume
effected maintaining final image homogeneity. to estimate any motion that may have occurred
Instead of a pencil beam, a box is positioned by using a similar rigid body technique. Each volume
the user and a 2D evaluation of the diaphragm is compared with the previous volume to calculate
position is used. The 2D-image provides much motion in six dimensions (3 translations and 3
more information making the technique broadly rotational axes). Then, in real time, the system uses
applicable. This lead to the emergence of excellent this information to adjust the acquisition parameters
quality “free breathing” or “multi-breath-hold” studies (the imaged volume) so that the brain stays in the
like 3D TSE MRCP. (See Figure 1.) same position in the image, no matter where the
head has moved. Siemens is the only vendor to
It’s not hard to see,
have implemented this strategy. It is called 3D-PACE
however, that navigator
and is used with functional MRI exams.3 3D-PACE
techniques provide little
prospectively adjusts gradient commands according
help in the brain where bulk
to 6-dimensional head motion providing accurate
motion of the entire imaged
fMRI results. (See Figure 2.)
volume is the problem.
Additionally, since this Emerging Strategies
motion is not periodic and In recent years there have been a number of new
Figure 1: T2 TSE 3D Restore;
there is no guarantee that methods proposed for motion control, though few
PAT 2; 2D PACE; 1 mm x 1 mm the head will ever move have caught on. Two methods of note are PROPELLER
x 1.5 mm; Body Matrix,
Spine Matrix.
back to the original position, and octant or cloverleaf navigators.
the user is left with only
post-processing techniques. A technique termed “periodically rotated overlapping
parallel lines with enhanced reconstruction”
3D Strategies (PROPELLER) was introduced by Pipe in 1999.4
Other methods have been developed specifically to Originally developed but not implemented on a
deal with this unpredictable bulk motion that is seen Siemens MR scanner, over the last 5 years this
in head examinations. Often rigid body registration method has received quite a bit of attention and
techniques are used as a post-processing strategy. has proven itself to be useful for motion correction
While from an ideal perspective, these should be in some cases. The PROPELLER technique collects
more than sufficient, practical issues such as partial data in concentric rectangular strips rotated about
volume effects and through-plane signal changes the k-space origin. (See Figure 3.) The central region
can create tremendous problems if all of the motion of k-space is sampled for every strip, which
control is left until after the acquisition is complete. (a) allows one to correct spatial inconsistencies
2
4. The results, however, have been positive. In a number
of studies, radiologists have preferred to view
PROPELLER images over conventional T2-weighted TSE
or EPI-DWI scans.6-8 One drawback, recently noted, was
Blade
that EPI-DWI is superior to PROPELLER for quantitative
width analysis (i.e. FA mapping) due to artifactual
high-signal bands in the PROPELLER images.9
X
A concern for PROPELLER is total time required. In
today’s clinical workflow, the goal is to decrease the
Y amount of time needed to perform an examination,
from patient set-up to scanning, etc. PROPELLER,
Figure 3: PROPELLER. however, increases the time it takes to perform a
scan. Specifically, it adds a factor of pi/2 to the
in position, rotation, and phase between strips, acquisition due to the oversampling of the center
(b) allows one to reject data based on a correlation of k-space.4 To its credit, this does increase SNR due
measure indicating through-plane motion, and to increased k-space sampling. Additionally, the series
(c) further decreases motion artifacts through of corrections that are applied to the 2D slices in
an averaging effect for low spatial frequencies. PROPELLER to account for translational, rotation,
However, while PROPELLER does acquire data and phase changes that may occur during acquisition
differently, all of the motion correction occurs each add to the reconstruction time. The intense
as a post-processing technique that attempts to post-processing of the PROPELLER technique adds
correct corrupted data instead of inline correction about 2 to 3 minutes of additional reconstruction
to start with the best data. time per scan.6
In PROPELLER, you can acquire any 2D T2-weighted In all, while PROPELLER can reduce apparent motion
turbo spin echo (TSE) scan4 or a diffusion weighted artifacts that appear in T2 and diffusion weighted
multi-shot TSE scan.5 (See Figures 4A–4B.) These are TSE exams, it fails to seamlessly fit into today’s
clinical workflow and is outperformed by traditional
EPI techniques for quantitative diffusion analysis.
Another new method for controlling motion is the
octant or cloverleaf navigator approach. Developed
by Dale and Van Der Kouwe in 2004, cloverleaf
navigators are an improved k-space trajectory
and associated mapping procedure that allows rapid,
inline correction or rotations and translations with
A B
minimal additional acquisition time.10, 11
Figures 4A–4B: Head with axial rotation in plane. Figure 4A head without The cloverleaf trajectory covers each of the principal
propeller; Standard TSE. Figure 4B head with propeller; motion corrected.
axes and three arcs, which connect each of the three
important images to be able to acquire without axis pairs. A complete navigator set takes only 2.2 ms
image artifacts, however, this falls far short of being inside of each TR to be played out. The inherent 3D
able to provide a full clinical exam, with both T1 nature of the navigator makes it appropriate for both
and IR, on an uncooperative patient. Additionally, 2D and 3D acquisitions and it could be added to
the PROPELLER technique does not provide through- almost any imaging sequence. This provides distinct
plane motion correction.4,6 So while a patient can advantages since it can be used for any contrast,
rotate their head “in-plane”, through-plane motion any acquisition method, and could be applied to
is accounted for by eliminating data. It is rather an entire study for an uncooperative patient.
unrealistic to think that a real patient would only
The navigator correction system works in concert
move their head in the imaging plane.
with a map of k-space in the vicinity of the navigator
3
5. acquired in a short preliminary mapping sequence of 1. Medley M and Yan H. Motion artifact suppression:
15 s. By playing out the navigator in each TR, a linear A review of post-processing techniques. Magnetic
Resonance Imaging. 10(4): 627-635, 1992.
mapping between the acquired navigator and the
preliminary map allows the angle of rotation to be 2. Ehman RL and Felmlee JP. Adaptive technique for high-
definition MR imaging of moving structures. Radiology.
determined with a simple matrix multiplication.
173(1): 255-263, 1989.
The changes due to translational and rotational
3. Thesen S, Heid O, Mueller E and Schad LR. Prospective
motion are then fed back to the MR system that acquisition corrections for head motion with image-
applies gradient corrections during the acquisition. based tracking for real-time fMRI. Magnetic Resonance
This technique carries with it the advantage of in Medicine. 44(3): 457-465, 2000.
finding and correcting motion during the acquisition, 4. Pipe JG. Motion correction with PROPELLER MRI:
as opposed to using post-processing. application to head motion and free-breathing
cardiac imaging. Magnetic Resonance in Medicine.
A very new and promising technique, cloverleaf 42(5): 963-969, 1999.
navigators have shown great promise for inline 5. Pipe JG, Farthing VG and Forbes KP. Multi-shot diffusion
control of motion without the drawback of additional weighted FSE using PROPELLER MRI. Magnetic
scan and reconstruction time. It is hoped that this Resonance in Medicine. 47(1): 42-52, 2002.
will provide a robust method for motion control, 6. Forbes KP, Pipe JG, Bird CR and Heiserman JE. PROPELLER
applicable to today’s demanding clinical environment, MRI: clinical testing of a novel technique for
but to date this technique is unproven clinically. quantification and compensation of head motion.
Journal of Magnetic Resonance Imaging. 14(3): 215-
Conclusion 222, 2001.
A series of motion correction techniques have 7. Forbes KP, Pipe JG, Karis JP, Farthing V and Heiserman JE.
Brain imaging in the usedated pediatric patient:
been proposed over the years. There is common
comparison of periodically rotated overlapping parallel
understanding that the underlying goal is to provide lines with enhanced reconstruction and single-shot fast
MRI to everyone who needs a scan. While many spin-echo sequences. AJNR American Journal of
believe this is best achieved through motion control, Neuroradiology. 24(5): 794-798, 2003.
there are still a number of retrospective correction 8. Forbes KP, Pipe JG, Karis JP and Heiserman JE. Improved
algorithms available. The new techniques, while image quality and detection of acute cerebral infarction
promising, have their drawbacks, as well. The hope with PROPELLER diffusion-weighted imaging. Radiology.
225(2): 551-555, 2002.
is that through further refinement and innovation,
9. Abe O, Mori H, Aoki S, Kunimatsu A, Hayashi N,
a robust method (or combination of methods) will
Masumoto T, Yamada H, Masutani Y, Kabasawa H and
provide perfect motion control for all patients. Ohtomo K. Periodically rotated overlapping parallel lines
with enhanced reconstruction-based diffusion tensor
imaging: comparison with echo planar imaging-based
diffusion tensor imaging. Journal of Computer Assisted
Tomography. 28(5): 654-660, 2004.
10. van der Kouwe AJ and Dale AM. Rapid real-time
prospective rigid body motion correction during
imaging using clover-leaf navigators. Proceedings of
the International Society of Magnetic Resonance in
Medicine. 11: 95, 2004.
11. van der Kouwe AJ and Dale AM. Real-time motion
correction using octant navigators. NeuroImage.
13(6): S48, 2001.
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