Signa Voyager MRI Artifact Solutions Guide

GE Signa Voyager Artifact tips and workarounds solutions guide provides quick resolutions to the most common MRI artifacts. Whether you are experiencing image quality issues or looking for the latest GE Signa Voyager applications resources, this article contains everything you need to know about image artifacts on the Signa Voyager 1.5T MRI platform. Use the table of contents below to quickly jump to a section or use ctrl+F to search by keyword.

The following information is for reference only. All procedures should be verified in the GE MRI Signa Voyager operator manual available for download at https://www.gehealthcare.com/support/documentation. MRIPETCTSOURCE is not responsible for the misuse of material. See disclaimer below for additional information.

Annefact Artifact

Annefact is a signal artifact that appears as ribbons of signal smeared through the image. This artifact is caused by signal generated outside the scan FOV that are detected by the receiver.

In FSE scans, Annefact appears as bright, ghosting signals through the image in the phase direction. It typically appears on sagittal spines or pelvis scans using a phased array surface coil.

Annefact artifacts originate far from the isocenter, where the gradients are non-linear, similar to a Star artifact. Uncompensated eddy currents in this area cause phase errors in the compressed signal. As a result, this signal is smeared through the image.

Tips to Prevent GE Signa Voyager MRI Annefact Artifact

• Select receive coils that match the imaging FOV, such as Spine 18 1, Spine 18 2, etc., to lessen the likelihood of picking up peripheral signals that are generated outside the FOV.
• Verify frequency direction is set to S/I for sagittal spine imaging
• Place a SAT Band anterior to the spine.

C-Spine MRI Annefact Artifact

An annefact is displayed in the following FSE sagittal cervical spine image, which was acquired with CTLOP, 24 cm FOV, and swapped phase and frequency.

To prevent a C-spine artifact, select 2 coils like CS12 that closely match the scan FOV and avoid swapping phase and frequency. Additionally, use Annefact Suppression User CV.

Knee MRI Annefact Artifact

Placing the HD Knee Array coil at isocenter can result in an annefact artifact on the sagittal or coronal knee images. To prevent this, the coil should be positioned right or left off-center, within a range of 60 to 120 mm. Specifically, the recommended positioning range is approximately 60 to 70 mm off-center.

High Baseline Noise on Spectrum Considerations

Several conditions can cause a high background noise on a spectrum. These include:

Under specific conditions, a high background noise can occur on a spectrum when setting a spectroscopy localized volume approximately 50 mm or farther from iso-center. Additionally, turning on the User CV AWS optimization can also cause this issue.

C-Spine Fat SAT (Bulk Susceptibility) Uniformity Artifact

The occurrence of poor chemical fat SAT uniformity in C-spine imaging is influenced by various factors. These include:

Poor chemical Fat Sat uniformity can arise in C-spine imaging due to poor B0 uniformity in the C-spine region. This phenomenon is commonly referred to as a bulk susceptibility artifact.

B0 uniformity depends on various factors such as the patient’s size, shape, and positioning within the magnet. A static magnetic field can become inhomogeneous within a patient due to their irregular geometry and the distribution of material magnetic susceptibility. As a result, certain regions of inhomogeneity can cause poor fat suppression.

In the C-spine region, for instance, variations in the B0 field exceeding 3 ppm can exist, which is roughly the fat-water separation range. Consequently, imaging sequences that rely on chemical saturation to achieve fat suppression are highly sensitive to Bo inhomogeneity, which can cause regions to exhibit partial or incomplete fat saturation.

Tips to Prevent FAT SAT Uniformity Artifact

To minimize poor chemical fat SAT uniformity and bulk susceptibility artifact in C-spine imaging:

• position the patient’s neck parallel to the main magnetic field.
• Use a STIR sequence with a TI time of 140 to 160 ms instead of using chemical FAT SAT, which is sensitive to B0 inhomogeneity.

DWI and DTI Ring Artifact

A ring-like artifact can occur on T2-weighted EPI DWI/DTI, ADC/eADC, and Synthetic DWI images due to intense orbit signal.

Using the HyperBand Imaging Option with the DWI scan and type-in PSD: epi2altoff can cause the ring artifact to occur on superior brain slices.

Tips to Prevent DWI and DTI Artifact

To minimize the artifact, position an angled anterior SAT band over the orbits (not the cortex) to suppress the orbit signal intensity.

The epi2alt type-in PSD is another method that potentially reduces eyeball artifact. It reverses or swaps the distortion direction from the default DWI PSD.

Gradient Echo Chemical Shift Artifact

When a voxel contains both fat and water and the TE is timed for the vectors to be in or out of phase, chemical shift effects can occur.

Boundaries between fat and tissues with much water can either be bright or dark. When using certain PSDs like FSPGR, one can select the TE as either In Phase or Out of Phase. Choosing In Phase will result in a bright fat/water border, while Out of Phase will make the fat/water boundary dark and structures will appear outlined with a black marker.

Tips to Prevent Gradient Echo Chemical Shift Artifact

To minimize this effect, select In Phase as the TE parameter or manually enter a TE parameter as close to the fat/water in-phase time as possible.

Signa Voyager MRI In-Flow Artifact

Normally, saturation effects cause a dark vessel signal in T1-weighted images. In regions with a short T1, this can be clinically confusing. An in-flow effect around the edge slices or in 2D multiple acquisitions with an interleaved slice order causes the vessel signal to become bright.

Tips to Prevent In-Flow Artifact

To minimize the artifact caused by slow flow signal, use the In-flow signal reduction User CV with 2D FSPGR or 2D Dual Echo.

Metal Artifact

MR conditional metal implants can cause ringing, stripe, signal void and image distortion artifacts.

Tips to Prevent Metal Artifacts

MAVRIC SL, a one-click imaging application, can reduce the artifacts, but not remove them entirely.

Non-Uniformity of Signal Artifact

The MRI RF receiver efficiently detects signals closest to it, which can cause non-uniform signal in the image. Surface coils show more localized bright areas close to the coil than volume coils. This variability may cause incomplete fat suppression in chemical fat suppression techniques.

Tips to Prevent Non-Uniformity Artifact

Consider using a different coil or applying coil intensity correction techniques to address non-uniform signal.

Instead of additional fat saturation techniques, try a STIR sequence.

For surface coils, localized bright areas close to the coil may appear, but PURE and SCIC/SCENIC techniques can help minimize these variations. Consult the PURE technique for more information on using compatible surface coils.

GE Signa Voyager MRI PROPELLER Artifact

PROPELLER generates unique or different artifacts. Below are ways to minimize them. Consider these trade-offs: as frequency resolution increases, crinkling increases; increase ETL to reduce crinkling. As ETL increases, TE increases; increase Bandwidth to lower TE. As Bandwidth increases, SNR decreases.

PROPELLER Crinkling Artifact

A crinkling artifact on PROPELLER sequences can be caused by:

• Using the wrong ETL. This may appear in the superior slices and the most common cause is low ETL protocol prescriptions. To resolve, increase the ETL
• Extreme patient movement
• Phase Wrap in Image

Tips to Prevent PROPELLER Crinkling Artifact

Increase scan FOV to fully contain the anatomy. If that does not resolve issue, increase ETL.

Top of Scalp Artifact

Not having enough data to perform motion correction causes top of scalp artifacts.

Tips to Prevent Top of Scalp Artifact

Try prescribing fewer slices to cover only anatomy of interest.

Blurred Images

Blurred images occur in all three PROPELLER applications due to inadequate blade matching, resulting in poor blade correlation. The GE syslog displays the message “Image quality may be degraded due to poor blade correlation…”

Signal Voids

Signal voids in DW PROPELLER can result in black holes on the diffusion-weighted images, but not in every scan. These voids may be caused by system calibrations out of spec, such as eddy currents. To resolve, contact your MRI service engineer to ensure system is within specification.

Ripples

Wrap can cause ripples in PROPELLER images, and they can be observed with all three applications.
However, due to the radial acquisition, the ripples look different. To prevent wrap, increase the FOV or reposition the slice prescription.

Annefact

All PROPELLER applications are susceptible to Annefact artifact, but it may appear differently due to the radial acquisition technique. To prevent or reduce Annefact:

• Select the receive coils that match the scan FOV. This lessens the likelihood of the MRI receivers picking up signal generated outside the scan region.
• Turn on the Accel checkbox and increase Phase Acceleration Factor to increase the the effective area of the blade.
• Toggling Fat Shift Direction shifts the artifact, but does not eliminate it. This can be used as a workaround to increase image quality in the area of interest.
• Select the Oversampling Factor, as indicated in the chart below.

Signa Voyager MRI RF Leak Artifact

In PROPELLER sequences, RF leak shows as criss-crossed lines. In GRE sequences, RF leak appears as a zipper artifact. To resolve, contact your MRI service engineer to troubleshoot source of RF leak.

RF Inhomogeneity Artifact

RF inhomogeneity artifacts appear as drop in signal intensity in a section of the anatomy. This often indicates the presence of ferromagnetic material or the failure of an MRI coil element.

First, verify with the patient that no artifact is caused by anything on or inside them. Then, perform manual prescan and inspect each coil element. Discontinue coil use if faulty receive channel is found. Consult with your MRI service engineer upon isolating a faulty element.

Shading Artifact

Shading artifacts appear as areas of reduced signal intensity or bands of signal cancellation. Improper positioning of the coil or patient often causes shading artifacts.

Tips to Prevent Shading Artifact

• To get the best signal from the patient, reposition the coil and/or the patient to match coil selection.
• Place the anatomy of interest in the center of the magnetic field, coil and the group of sections.
• Make sure patient does not come in direct contact with the coil by placing a pad or folded sheet.

Star Artifact

Star artifact is a peripheral signal artifact that appears as a bright spot close to the middle of the image, caused by signals generated outside the desired FOV. The signals that originate far from isocenter and are not crushed out in the non-linear region.

Tips to Prevent Shading Artifact

Avoid swapping phase and frequency, use Annefact Suppression User CV, and use a 3-coil selection, such as USCTS234, for closer surface coil coverage matching the scan FOV.

Surface Coil Artifact

When scanning with surface coils, keep these basic principles in mind:

• To optimize SNR for the desired scan time, match the coil to the anatomy. Match the FOV to the size of the coil or number of coil elements selected.
• Aliased signal from tissue outside the FOV can be removed by oversampling in the phase direction.
• It may be necessary to use an alternative coil (such as a Flex coil) to get the best image possible.
• Select a coil configuration and FOV based on the number of elements chosen, and always read the manual for the particular coil configuration you are using.
• Always read the coil manual for the specific coil configuration you are using.
• Be aware of and follow safe MR scanning procedures.

Truncation Artifact

When k-space data is not fully acquired, the truncation artifact can appear around bright tissue and spread along the partial k-space direction. Additionally, this artifact is intensified if the brightness changes sharply.

Tips to Reduce Truncation Artifact

• Reduce scan FOV to avoid sharp changes in contrast
• Increase matrix values (256 x 256 or 512 x 512) to apply full k-space data acquisition.
• Change TE value to Min Full if Minimum is selected

Worm Hole Artifact

Diffusion Weighted Echo Planar Imaging combines partial k-space acquisition with homodyne reconstruction. Rotational motion during the diffusion lobe shifts k-space data, causing wormhole-like artifacts. The artifact frequency increases with higher b-values due to stronger diffusion gradient lobes.

Tips to Prevent Worm Hole Artifact

Non-conductive padding can be used to support the sides of the patient’s head and restraints can be applied to prevent rotational motion in the A/P direction to prevent in-plane rotational motion.

GE Signa Voyager MRI Artifact Overview

In conclusion, the GE Signa Voyager platform offers flexible imaging options and workarounds to resolve MRI artifacts. We are happy to provide you with the radiology resources to resolve your GE Signa Voyager MRI artifact. You can find related resources in the GE Signa Voyager Operator Manual Procedures page. Also, consider signing up to our newsletter below to stay up to date on the latest technical resources.

Additional Resources

• GE MRI ZIP 512 Explained
• GE MRI Protocols and imaging Options
• GE MRI Technologists Resources Page
• MRIPETCTSOURCE YouTube Channel

Additional information about MRI artifacts available at