Notes in 17 Magnetic resonance imaging (MRI) physics

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Status	Last Update	Fields
Published	05/01/2023	Imaging Physics: MRIMRI is {{c1::not contraindicated::contraindicated/not contraindicated}} during pregnancy
Published	05/01/2023	Imaging Physics: MRI Gadolinium is {{c1::contraindicated::contraindicated/not contraindicated}} during pregnancy
Published	05/01/2023	Imaging Physics: MRI {{c1::Quenching}} causes loss of {{c2::superconductivity}} of MRI scanner magnet coils
Published	05/01/2023	Imaging Physics: MRI Uncontrolled quenching causes the explosive release of {{c1::helium}} gas, which can then displace {{c1::oxygen}}.
Published	05/01/2023	Imaging Physics: MRI Safety For safety, the {{c1::fringe field}} outside of the MRI controlled access area cannot exceed {{c2::5}} Gauss
Published	05/01/2023	Imaging Physics: MRI Safety MR systems used for clinical imaging do not typically utilize {{c1::static}} magnetic field strength > {{c2::4}} T
Published	05/01/2023	Imaging Physics: MRI Safety {{c1::Time-varying}} magnetic fields can result in peripheral nerve {{c2::stimulation}}, muscle {{c2::movement}}, and disc…
Published	05/01/2023	Imaging Physics: MRI Safety MR systems used for clinical imaging do not typically utilize {{c1::time-varying}} magnetic fields sufficient to produce s…
Published	05/01/2023	Imaging Physics: MRI Safety MR systems used for clinical imaging do not typically utilize {{c1::radiofrequency}} fields that produce a {{c2::core::bod…
Published	05/01/2023	Imaging Physics: MRI Safety Conductive {{c1::loops}} can cause local heating that can lead to a contact burn
Published	05/01/2023	Imaging Physics: MRI Safety {{c1::Metallic::What material}} objects can absorb radiofrequency energy and become hot
Published	05/01/2023	Imaging Physics: MRI Safety The {{c1::specific absorption ratio (SAR)}} is a measure of {{c2::radiofrequency power}} absorbed per {{c2::unit mass}}
Published	05/01/2023	Imaging Physics: MRI Safety The specific absorption ratio (SAR) can be {{c1::de}}creased by {{c2::de}}creasing field strength
Published	05/01/2023	Imaging Physics: MRI Safety The specific absorption ratio (SAR) can be {{c1::in}}creased by {{c2::in}}creasing flip angle
Published	05/01/2023	Imaging Physics: MRI Safety The specific absorption ratio (SAR) can be {{c1::in}}creased by {{c2::de}}creasing pulse duration
Published	05/01/2023	Imaging Physics: MRI Safety The specific absorption ratio (SAR) can be {{c1::de}}creased by {{c2::in}}creasing the repetition time of the sequenc…
Published	05/01/2023	Imaging Physics: MRI Safety The specific absorption ratio (SAR) can be {{c1::both increased and de}}creased by changing the sequence type
Published	05/01/2023	Imaging Physics: MRI SafetyTime-varying magnetic fields interact with the main static magnetic field, causing {{c1::gradient coils}} to vibrate and cr…
Published	05/01/2023	Imaging Physics: MRI Safety MR systems used for clinical imaging do not typically utilize {{c1::time-varying}} magnetic fields that produce acoustic …
Published	05/01/2023	Imaging Physics: MRISignal to noise ratio (SNR) {{c1::in}}creases with {{c2::in}}creasing voxel signal intensity (I)
Published	05/01/2023	Imaging Physics: MRISignal to noise ratio (SNR) {{c1::in}}creases with {{c2::in}}creasing voxel volume (voxelx,y,z)
Published	05/01/2023	Imaging Physics: MRISignal to noise ratio (SNR) {{c1::in}}creases with {{c2::in}}creasing number of excitations (NEX)
Published	05/01/2023	Imaging Physics: MRISignal to noise ratio (SNR) {{c1::de}}creases with {{c2::in}}creasing receiver bandwith (BW)
Published	05/01/2023	Imaging Physics: MRISignal to noise ratio (SNR) {{c1::in}}creases with {{c2::in}}creasing magnetic field strength (B)
Published	05/01/2023	Imaging Physics: MRIA tissue’s {{c1::T1}} signal intensity depends on {{c2::longitudinal}} relaxation time of protons
Published	05/01/2023	Imaging Physics: MRIA tissue’s {{c1::T2}} signal intensity depends on {{c2::transverse}} relaxation time of protons
Published	05/01/2023	Imaging Physics: MRI {{c1::TR}} is also known as the {{c2::repetition}} time
Published	05/01/2023	Imaging Physics: MRI {{c1::TR}} is the amount of time between {{c2::sequential radiofrequency pulses::which two pulses}}.
Published	05/01/2023	Imaging Physics: MRI {{c1::T1}} image contrast depends on T{{c2::R (Time to Repetition)}}
Published	05/01/2023	Imaging Physics: MRI {{c1::TE}} is also known as the {{c2::echo}} time
Published	05/01/2023	Imaging Physics: MRI {{c1::T2}} image contrast depends on T{{c2::E (time to echo)}}
Published	05/01/2023	Imaging Physics: MRI {{c1::T1}} weighted images are obtained with a {{c2::short}} Time to Repetition (TR) and a {{c2::short}} Time to E…
Published	05/01/2023	Imaging Physics: MRI {{c1::T2}} weighted images are obtained with a {{c2::long}} Time to Repetition (TR) and {{c2::long}} Time to Echo …
Published	05/01/2023	Imaging Physics: MRI {{c1::PD}} weighted images are obtained with a {{c2::long}} Time to Repetition (TR) and {{c2::short}} Time to Echo…
Published	05/01/2023	Imaging Physics: MRI {{c1::PD}} weighted images have the {{c2::highest::highest/lowest}} {{c2::signal to noise ratio::signal to noise ratio/contrast}}
Published	05/01/2023	Imaging Physics: MRI {{c1::PD}} weighted images have the {{c2::lowest::highest/lowest}} {{c2::contrast::signal to noise ratio/contrast}}
Published	05/01/2023	Imaging Physics: MRIFat and subacute blood have {{c1::short}} T1 relaxation times and are therefore {{c1::hyper}}intense on T1-wei…
Published	05/01/2023	Imaging Physics: MRIWater has a {{c1::long}} T2 relaxation time and is therefore {{c1::hyper}}intense on T2-weighted imaging
Status	Last Update	Fields