“Good to Know” Canon MRI
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“Good to Know” Canon MRI
Canon’s Good to Know helps to make complex topics simple by providing explanations from our expert employees. We try to make it easy to understand with videos and links to useful information, and PDFs are made available to print out if you would like to keep the information handy. If you would like more information or to suggest ideas for other topics, please email us on CMSC-goodtoknow@medical.canon and we will have our experts get in touch with you.
WHAT?
IMC is a Deep Learning-based motion correction method to improve the quality of images affected by patient motion.
WHY?
Patient motion creates artifacts that can cause images to lose their diagnostic value and may necessitate a repeated scan.
WHEN?
IMC can reduce imaging artifacts from sporadic, rigid, and nonrigid patient motion in fast spin-echo (FSE) sequences. IMC supports multiple imaging weightings such as T2, T1 IR, STIR & FLAIR, and in any plane for brain and cervical spine examinations.
IMC is a Deep Learning-based motion correction method to improve the quality of images affected by patient motion.
WHY?
Patient motion creates artifacts that can cause images to lose their diagnostic value and may necessitate a repeated scan.
WHEN?
IMC can reduce imaging artifacts from sporadic, rigid, and nonrigid patient motion in fast spin-echo (FSE) sequences. IMC supports multiple imaging weightings such as T2, T1 IR, STIR & FLAIR, and in any plane for brain and cervical spine examinations.
Additional Links and Resources
Internal links
White paper on IMC solution (by Srikant Kamesh Iyer, PhD)
External links (may require logins)
Conference abstract on IMC evaluation (ISMRM 2023)
Workshop abstract on shuffle encoding technique (ISMRM Workshop 2022)
White paper on IMC solution (by Srikant Kamesh Iyer, PhD)
External links (may require logins)
Conference abstract on IMC evaluation (ISMRM 2023)
Workshop abstract on shuffle encoding technique (ISMRM Workshop 2022)
WHAT?
Metal artifact reduction strategies and sequences are designed to reduce susceptibility artifacts caused by the presence of metal in an MR imaging volume.
WHY?
In MRI, most metallic implants cause artifacts which can interfere with the anatomy of interest in the image by causing distortion or signal loss, due primarily to strong magnetic susceptibility.
WHEN?
In patients with metallic implants, artifact reduction techniques are especially useful for reducing the interference of related artifacts thus facilitating a more confident diagnosis.
Metal artifact reduction strategies and sequences are designed to reduce susceptibility artifacts caused by the presence of metal in an MR imaging volume.
WHY?
In MRI, most metallic implants cause artifacts which can interfere with the anatomy of interest in the image by causing distortion or signal loss, due primarily to strong magnetic susceptibility.
WHEN?
In patients with metallic implants, artifact reduction techniques are especially useful for reducing the interference of related artifacts thus facilitating a more confident diagnosis.
WHAT?
A specialized pulse sequence modified from original Look Locker technique for myocardial T1 mapping.
WHY?
T1 measurement could be time consuming due to multiple data acquisition successively after magnetization inversion. MOLLI techniques enable a fast assessment of myocardial T1 in one breath hold.
WHEN?
Myocardial T1 mapping provides a non-invasive quantitative tool for tissue characterization in myocardial disease.
A specialized pulse sequence modified from original Look Locker technique for myocardial T1 mapping.
WHY?
T1 measurement could be time consuming due to multiple data acquisition successively after magnetization inversion. MOLLI techniques enable a fast assessment of myocardial T1 in one breath hold.
WHEN?
Myocardial T1 mapping provides a non-invasive quantitative tool for tissue characterization in myocardial disease.
WHAT?
Fast scans of the whole brain every few seconds along a rest-task paradigm or during resting state.
WHY?
To assess neural activity based on the detection of blood oxygen level dependent (BOLD) changes.
WHEN?
For multiple purposes such as functional area mapping, evaluation of brain state (related to stroke, trauma or neurodegenerative disorders) and pre-surgical planning.
Fast scans of the whole brain every few seconds along a rest-task paradigm or during resting state.
WHY?
To assess neural activity based on the detection of blood oxygen level dependent (BOLD) changes.
WHEN?
For multiple purposes such as functional area mapping, evaluation of brain state (related to stroke, trauma or neurodegenerative disorders) and pre-surgical planning.
Additional Links and Resources
External links (may require logins)
Simple explanations on fMRI by mriquestions.com
Recommendations regarding fMRI paradigms (ASFNR website)
Wikipedia webpage of QIBA profiles, including fMRI for sensorimotor mapping
Peer-reviewed paper on aging biomarkers, including rs-fMRI (Mech Ageing Dev. 2020)
Task-fMRI part of the Human connectome project
Simple explanations on fMRI by mriquestions.com
Recommendations regarding fMRI paradigms (ASFNR website)
Wikipedia webpage of QIBA profiles, including fMRI for sensorimotor mapping
Peer-reviewed paper on aging biomarkers, including rs-fMRI (Mech Ageing Dev. 2020)
Task-fMRI part of the Human connectome project
WHAT?
A family of MR angiography techniques that utilize fresh spins to depict the contrast in blood vessels as an alternative to an injection of an exogenous contrast agent. In particular, Fresh Blood Imaging (FBI), Flow Spoiled FBI (FS-FBI) and Time-Spatial Labeling Inversion Pulse (Time-SLIP), are discussed.
WHY?
Non-contrast angiography (NC-MRA) provides the safest option for MR Angiography. It can exquisitely depict arteries and veins throughout the body in 3 dimensions, while eliminating the need for gadolinium-based contrast agents.
WHEN?
Any time visualization of the arteries or veins is needed for clinical diagnosis and follow-up related to narrowing or blockage of blood vessels, NC-MRA can be used for evaluation. NC-MRA is especially important for those patients who have a contraindication to exogenous contrast agents.
A family of MR angiography techniques that utilize fresh spins to depict the contrast in blood vessels as an alternative to an injection of an exogenous contrast agent. In particular, Fresh Blood Imaging (FBI), Flow Spoiled FBI (FS-FBI) and Time-Spatial Labeling Inversion Pulse (Time-SLIP), are discussed.
WHY?
Non-contrast angiography (NC-MRA) provides the safest option for MR Angiography. It can exquisitely depict arteries and veins throughout the body in 3 dimensions, while eliminating the need for gadolinium-based contrast agents.
WHEN?
Any time visualization of the arteries or veins is needed for clinical diagnosis and follow-up related to narrowing or blockage of blood vessels, NC-MRA can be used for evaluation. NC-MRA is especially important for those patients who have a contraindication to exogenous contrast agents.
Additional Links and Resources
Internal links
White paper on renal artery stenosis diagnosis (by Cesar H. Nomura, PhD)
White paper on fresh blood imaging for peripheral angiography (by Timothy Albert, MD)
White paper on Time-Spatial Labeling Inversion Pulse (by Timothy Albert, MD)
External links (may require logins)
Peer-reviewed paper on renal 3D MR angiography (MAGMA 2020)
Review article on Non-contrast enhanced MR angiography (JMRI 2012)
Peer-reviewed paper on portography with time-spatial labeling inversion pulses (JMRI 2009)
White paper on renal artery stenosis diagnosis (by Cesar H. Nomura, PhD)
White paper on fresh blood imaging for peripheral angiography (by Timothy Albert, MD)
White paper on Time-Spatial Labeling Inversion Pulse (by Timothy Albert, MD)
External links (may require logins)
Peer-reviewed paper on renal 3D MR angiography (MAGMA 2020)
Review article on Non-contrast enhanced MR angiography (JMRI 2012)
Peer-reviewed paper on portography with time-spatial labeling inversion pulses (JMRI 2009)
WHAT?
Acquisition of diffusion-weighted images (DWI) using multiple b-values.
WHY?
To improve sensitivity of DWI and obtain further information regarding tissue behavior (apart from pure diffusion).
WHEN?
For several clinical applications and all body regions, but mostly used for oncological purposes.
Acquisition of diffusion-weighted images (DWI) using multiple b-values.
WHY?
To improve sensitivity of DWI and obtain further information regarding tissue behavior (apart from pure diffusion).
WHEN?
For several clinical applications and all body regions, but mostly used for oncological purposes.
WHAT?
PIQE is a solution designed to increase the reconstructed matrix size, providing finer resolution while maintaining or improving SNR.
WHY?
PIQE can lead to a higher throughput and/or a better clinical confidence.
WHEN?
PIQE can be used on 2D Fast Spin Echo (FSE) sequences, at both 1.5 and 3T, especially when SNR is low but more sharpness is needed.
PIQE is a solution designed to increase the reconstructed matrix size, providing finer resolution while maintaining or improving SNR.
WHY?
PIQE can lead to a higher throughput and/or a better clinical confidence.
WHEN?
PIQE can be used on 2D Fast Spin Echo (FSE) sequences, at both 1.5 and 3T, especially when SNR is low but more sharpness is needed.
Additional Links and Resources
Internal links
Good to Know on AiCE solution (by Hung Do, PhD)
White paper on PIQE testimonials (by MD and Daniel Chow, MD)
External links (may require logins)
Peer-reviewed paper on PIQE applied to DWI in brain patients (Neuroradiology 2023)
Conference abstract on PIQE development (ISMRM 2023)
Conference abstract on PIQE clinical validation on knee patients (ISMRM 2023)
Good to Know on AiCE solution (by Hung Do, PhD)
White paper on PIQE testimonials (by MD and Daniel Chow, MD)
External links (may require logins)
Peer-reviewed paper on PIQE applied to DWI in brain patients (Neuroradiology 2023)
Conference abstract on PIQE development (ISMRM 2023)
Conference abstract on PIQE clinical validation on knee patients (ISMRM 2023)
WHAT?
The Shape Coil is part of a new line of coil technology, offering flexibility in design for imaging many regions of the body including the torso, pelvis, joints, bones and extremities.
WHY?
The Shape Coil is flexible, soft, and light. It can be adapted to conform with each patient’s body shape and anatomy to improve patient comfort.
WHEN?
The Shape Coil can be used when more flexibility in positioning, orientation, acceleration, or coverage than traditional rigid or Flex coils is needed.
The Shape Coil is part of a new line of coil technology, offering flexibility in design for imaging many regions of the body including the torso, pelvis, joints, bones and extremities.
WHY?
The Shape Coil is flexible, soft, and light. It can be adapted to conform with each patient’s body shape and anatomy to improve patient comfort.
WHEN?
The Shape Coil can be used when more flexibility in positioning, orientation, acceleration, or coverage than traditional rigid or Flex coils is needed.
WHAT?
Elastography is an imaging technique that creates a map where the pixel value represents the stiffness of tissue (measured as the elastic modulus in kilopascals, kPa) at a given location.
WHY?
In many diseases, tissue stiffness can change. For example, stiffness increases with increasing fibrosis, which is directly linked to the clinical outcome of many diseases, such as liver cirrhosis, hepatitis, and steatohepatitis.
WHEN?
MRE is the most effective non-invasive technique for diagnosis, staging, disease monitoring, and treatment follow-up for multiple chronic liver diseases.
Elastography is an imaging technique that creates a map where the pixel value represents the stiffness of tissue (measured as the elastic modulus in kilopascals, kPa) at a given location.
WHY?
In many diseases, tissue stiffness can change. For example, stiffness increases with increasing fibrosis, which is directly linked to the clinical outcome of many diseases, such as liver cirrhosis, hepatitis, and steatohepatitis.
WHEN?
MRE is the most effective non-invasive technique for diagnosis, staging, disease monitoring, and treatment follow-up for multiple chronic liver diseases.
Additional Links and Resources
External links (may require logins)
Website of Resoundant (MRE Hardware provider)
Wikipedia webpage of QIBA profiles, including MR Elastography of the liver
Review article on MRE guidelines (Abdom Radiol 2022)
Review article on the MRE accuracy for staging liver fibrosis in patients (Clin Gastroenterol Hepatol 2015)
Review article on MRE, laboratory tests and ultrasound to detect fibrosis in patients (Hepatology 2017)
Website of Resoundant (MRE Hardware provider)
Wikipedia webpage of QIBA profiles, including MR Elastography of the liver
Review article on MRE guidelines (Abdom Radiol 2022)
Review article on the MRE accuracy for staging liver fibrosis in patients (Clin Gastroenterol Hepatol 2015)
Review article on MRE, laboratory tests and ultrasound to detect fibrosis in patients (Hepatology 2017)
WHAT?
An MRI pulse sequence that allows acquisition of multi-echo data with ultra short echo times (TEs).
WHY?
Ultra short TEs allows reception of signals from tissues with short T2* which can not be obtained with conventional field echo (gradient echo) sequences.
WHEN?
UTE multi-echo is available at both 1.5T and 3T and can be used to visualize tissues with short T2* and to generate associated T2* maps.
An MRI pulse sequence that allows acquisition of multi-echo data with ultra short echo times (TEs).
WHY?
Ultra short TEs allows reception of signals from tissues with short T2* which can not be obtained with conventional field echo (gradient echo) sequences.
WHEN?
UTE multi-echo is available at both 1.5T and 3T and can be used to visualize tissues with short T2* and to generate associated T2* maps.
WHAT?
A deep learning based reconstruction method for MRI that intelligently removes noise while maintaining feature integrity.
WHY?
To increase SNR of the reconstructed images. This increased SNR could be translated to increased resolution and/or shortened scan time. This could also enable high field-like image quality without high-field challenges (e.g. higher cost, B0 & B1 inhomogeneity, etc.).
WHEN?
Applicable to all anatomies and available at both 1.5T and 3T, for both wide and narrow bore system.
A deep learning based reconstruction method for MRI that intelligently removes noise while maintaining feature integrity.
WHY?
To increase SNR of the reconstructed images. This increased SNR could be translated to increased resolution and/or shortened scan time. This could also enable high field-like image quality without high-field challenges (e.g. higher cost, B0 & B1 inhomogeneity, etc.).
WHEN?
Applicable to all anatomies and available at both 1.5T and 3T, for both wide and narrow bore system.
Additional Links and Resources
Internal links
White paper on knee exploration at 3T using AiCE (by Garry Gold, MD PhD)
White paper on full brain exploration at 3T using AiCE (by Vincent Dousset, MD PhD)
White paper on AiCE explanation (by Hung Do, PhD)
External links (may require logins)
Peer-reviewed paper on brain imaging at 3T using AiCE (Magn Reson Med Sci 2020)
Peer-reviewed paper on non-contrast coronary angiography at 3T using AiCE (Can Assoc Radiol J 2021)
Conference abstract on quantitative imaging on brain at 3T using AiCE (ISMRM 2020)
Conference abstract on multi-anatomy imaging at 1.5T using AiCE (ISMRM 2021)
Conference abstract on short scan time imaging at 1.5T using AiCE (ISMRM 2021)
White paper on knee exploration at 3T using AiCE (by Garry Gold, MD PhD)
White paper on full brain exploration at 3T using AiCE (by Vincent Dousset, MD PhD)
White paper on AiCE explanation (by Hung Do, PhD)
External links (may require logins)
Peer-reviewed paper on brain imaging at 3T using AiCE (Magn Reson Med Sci 2020)
Peer-reviewed paper on non-contrast coronary angiography at 3T using AiCE (Can Assoc Radiol J 2021)
Conference abstract on quantitative imaging on brain at 3T using AiCE (ISMRM 2020)
Conference abstract on multi-anatomy imaging at 1.5T using AiCE (ISMRM 2021)
Conference abstract on short scan time imaging at 1.5T using AiCE (ISMRM 2021)
WHAT?
Arterial Spin Labeling (ASL) method allows quantitative imaging of blood flow perfusion without the use of external contrast agent.
WHY?
Non-contrast angiography (NC-MRA) provides the safest option for MR Angiography. It can exquisitely depict arteries and veins throughout the body in 3 dimensions, while eliminating the need for gadolinium-based contrast agents.
WHEN?
To study perfusion disorders such as stroke or blood flow alterations induced by cancer, epilepsy, and neurodegenerative diseases.
Arterial Spin Labeling (ASL) method allows quantitative imaging of blood flow perfusion without the use of external contrast agent.
WHY?
Non-contrast angiography (NC-MRA) provides the safest option for MR Angiography. It can exquisitely depict arteries and veins throughout the body in 3 dimensions, while eliminating the need for gadolinium-based contrast agents.
WHEN?
To study perfusion disorders such as stroke or blood flow alterations induced by cancer, epilepsy, and neurodegenerative diseases.
WHAT?
Calculate new diffusion-weighted images from acquired images.
WHY?
To obtain additional diffusion information of the tissues without additional scan time.
WHEN?
Mostly used for oncologic purposes; high b-value images may result in better tumor conspicuity.
Calculate new diffusion-weighted images from acquired images.
WHY?
To obtain additional diffusion information of the tissues without additional scan time.
WHEN?
Mostly used for oncologic purposes; high b-value images may result in better tumor conspicuity.
WHAT?
Acceleration technique based on incoherent undersampling in k-space.
It relies on the principles of compressed sensing technology.
WHY?
Compressed SPEEDER allows scan time reduction with higher acceleration factors than conventional SPEEDER while avoiding aliasing artifacts.
WHEN?
It is recommended for high-matrix situations, especially when the scanning conditions do not support traditional coil based parallel imaging.
Acceleration technique based on incoherent undersampling in k-space.
It relies on the principles of compressed sensing technology.
WHY?
Compressed SPEEDER allows scan time reduction with higher acceleration factors than conventional SPEEDER while avoiding aliasing artifacts.
WHEN?
It is recommended for high-matrix situations, especially when the scanning conditions do not support traditional coil based parallel imaging.
Additional Links and Resources
Internal links
Good to Know on Parallel Imaging (by Min Xu, PhD)
White Paper on time reduction and additional benefits for MSK protocols (by Xavier Alomar, MD)
White Paper on workflow acceleration in neuro imaging (by Benoit Doche de Laquintane, MD)
White Paper on knee pathologies combining Compressed SPEEDER and AiCE (by Xavier Alomar, MD and Elena Ferre)
External links (may require logins)
Article on Compressed Sensing description and applications (IEEE Signal Processing Magazine 2008)
Review of Compressed Sensing from signal processing perspective (BMC Biomedical Engineering 2019)
Youtube Video on maths behind Compressed Sensing (by Steve Brunton, PhD)
Good to Know on Parallel Imaging (by Min Xu, PhD)
White Paper on time reduction and additional benefits for MSK protocols (by Xavier Alomar, MD)
White Paper on workflow acceleration in neuro imaging (by Benoit Doche de Laquintane, MD)
White Paper on knee pathologies combining Compressed SPEEDER and AiCE (by Xavier Alomar, MD and Elena Ferre)
External links (may require logins)
Article on Compressed Sensing description and applications (IEEE Signal Processing Magazine 2008)
Review of Compressed Sensing from signal processing perspective (BMC Biomedical Engineering 2019)
Youtube Video on maths behind Compressed Sensing (by Steve Brunton, PhD)
WHAT?
One fat suppression approach based on the difference between the precessional frequencies of fat and water protons.
WHY?
To get a more efficient and reproducible fat signal suppression technique to improve visualization of lesions.
WHEN?
One fat suppression approach based on the difference between the precessional frequencies of fat and water protons.
WHY?
To get a more efficient and reproducible fat signal suppression technique to improve visualization of lesions.
WHEN?
- For varied clinical applications, initially focused on abdominal regions, and then extended to musculoskeletal imaging, such as the neck, spine, the knee, brachial plexus, and the hands.
- Useful when conventional fat suppression technique is not reliable (large FOV, neck and plexus, off-center imaging...)
Additional Links and Resources
Internal links
White paper on clinical application of Dixon technique on neck region (by Seppo Kortelainen, MD)
White paper on efficiency and usefulness of Dixon technique on the whole spine and the abdominal region (by Akihiko Arakawa, MD)
Good to Know on Fat Fraction Quantification (by Mo Kadbi, PhD)
External links (may require logins)
Peer-review paper on Dixon technique applied to knee exploration at 3T (J Med Radiat Sci 2019)
Simple explanations on Dixon technique by mriquestions.com
Review article on Dixon technique (JMR 2008)
White paper on clinical application of Dixon technique on neck region (by Seppo Kortelainen, MD)
White paper on efficiency and usefulness of Dixon technique on the whole spine and the abdominal region (by Akihiko Arakawa, MD)
Good to Know on Fat Fraction Quantification (by Mo Kadbi, PhD)
External links (may require logins)
Peer-review paper on Dixon technique applied to knee exploration at 3T (J Med Radiat Sci 2019)
Simple explanations on Dixon technique by mriquestions.com
Review article on Dixon technique (JMR 2008)
WHAT?
A single breath-hold multi-echo Field Echo scan to accurately and reliably measure Proton Density Fat Fraction (PDFF) and R2*, even in the presence of increased iron concentration.
WHY?
To simultaneously provide, with one scan, quantitative maps of liver fat and R2*, in- & opposed-phase images, and fat- & water-only images.
WHEN?
Quantifying hepatic fat content and iron accumulation is needed for diagnosis, severity grading, disease monitoring, or treatment response assessment.
A single breath-hold multi-echo Field Echo scan to accurately and reliably measure Proton Density Fat Fraction (PDFF) and R2*, even in the presence of increased iron concentration.
WHY?
To simultaneously provide, with one scan, quantitative maps of liver fat and R2*, in- & opposed-phase images, and fat- & water-only images.
WHEN?
Quantifying hepatic fat content and iron accumulation is needed for diagnosis, severity grading, disease monitoring, or treatment response assessment.
WHAT?
MRI images are created by gathering data from what is known in physics as the k-space. Parallel imaging (PI) under-samples data from the k-space by combining signal coming from multiple coils in parallel.
WHY?
By under-sampling data, we can speed-up scan time as less data is required in the acquisition phase.
WHEN?
Parallel Imaging can be used in several ways:
To go faster: higher patient throughput, shorter patient breath-hold, functional MRI, MR Angiography, reduce motion artifacts.
To reduce susceptibility artifacts : single shot EPI with Exsper(diffusion, DTI).
MRI images are created by gathering data from what is known in physics as the k-space. Parallel imaging (PI) under-samples data from the k-space by combining signal coming from multiple coils in parallel.
WHY?
By under-sampling data, we can speed-up scan time as less data is required in the acquisition phase.
WHEN?
Parallel Imaging can be used in several ways:
To go faster: higher patient throughput, shorter patient breath-hold, functional MRI, MR Angiography, reduce motion artifacts.
To reduce susceptibility artifacts : single shot EPI with Exsper(diffusion, DTI).
WHAT?
Advanced approach to reduce 3D imaging scan time by utilizing efficient k-space sampling methods.
WHY?
To acquire 3D images faster, with up to about 50 % reduction in the scan time.
WHEN?
Applicable when acquiring 3D volumes in various anatomies. Some examples include brain imaging or abdominal imaging where breath-holds are required.
Advanced approach to reduce 3D imaging scan time by utilizing efficient k-space sampling methods.
WHY?
To acquire 3D images faster, with up to about 50 % reduction in the scan time.
WHEN?
Applicable when acquiring 3D volumes in various anatomies. Some examples include brain imaging or abdominal imaging where breath-holds are required.
Additional Links and Resources
Internal links
White paper on standardized 3D brain MR examination in 6 minutes (by Vincent Dousset, MD PhD)
White paper on high resolution 3D free breathing technique (by Kohei Hamamoto, MD)
External links (may require logins)
Peer-reviewed paper on Fast 3D for breath-hold 3D magnetic resonance cholangiopancreatography (Eur J Radiol 2021)
Peer-reviewed paper on Fast 3D and AiCE for non-contrast MR coronary angiography (Can Assoc Radiol J 2021)
Conference abstract on Fast 3D wheel for cerebral MR angiography (RSNA 2021)
Conference abstract on fast 3D techniques to reduce scan time (RSNA 2021)
White paper on standardized 3D brain MR examination in 6 minutes (by Vincent Dousset, MD PhD)
White paper on high resolution 3D free breathing technique (by Kohei Hamamoto, MD)
External links (may require logins)
Peer-reviewed paper on Fast 3D for breath-hold 3D magnetic resonance cholangiopancreatography (Eur J Radiol 2021)
Peer-reviewed paper on Fast 3D and AiCE for non-contrast MR coronary angiography (Can Assoc Radiol J 2021)
Conference abstract on Fast 3D wheel for cerebral MR angiography (RSNA 2021)
Conference abstract on fast 3D techniques to reduce scan time (RSNA 2021)
