DOI: 10.1148/rg.27si075514
Breast MR Imaging Artifacts: How to Recognize and Fix Them1
Jennifer A. Harvey, MD,
R. Edward Hendrick, PhD,
Jennifer M. Coll, MD,
Brandi T. Nicholson, MD,
Brian T. Burkholder, RT, and
Michael A. Cohen, MD
1 From the Department of Radiology, University of Virginia, PO Box 800170, Charlottesville, VA 22908 (J.A.H., J.M.C., B.T.N., B.T.B., M.A.C.); and Lynn Sage Comprehensive Breast Center, Northwestern University’s Feinberg Medical School and Northwestern Memorial Hospital, Chicago, Ill (R.E.H.). Presented as an education exhibit at the 2006 RSNA Annual Meeting. Received March 12, 2007; revision requested April 5 and received May 3; accepted May 10. J.A.H. is a researcher with GE Healthcare, Wyeth, and Organon; R.E.H. is with the speakers’ bureau of GE Healthcare and a member of the medical advisory boards of BioLucent and Koning; all remaining authors have no financial relationships to disclose.
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Figure 1. Improper positioning of the breasts in the breast coil. Sagittal T1-weighted scout MR image (repetition time msec/echo time msec = 20/5) demonstrates signal intensity changes at the superior breast (arrowhead) and inclusion of the upper abdomen (arrow), findings that indicate that the patient is centered too cephalad in the coil. The approximate location of the coil aperture is circled.
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Figure 2a. Improper positioning. (a) Axial T1-weighted MR image (4/1) shows how, if the breasts are not pulled down into the coil, portions of the breast tissue remain above the coil (arrow) between the chest wall and the center partition of the coil. Because this area is compressed by the patient’s body weight due to prone positioning, the contrast enhancement of the compressed area may be poor. (b) On an axial T1-weighted MR image (4/1) obtained with improved patient positioning, no breast tissue remains above the coil.
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Figure 2b. Improper positioning. (a) Axial T1-weighted MR image (4/1) shows how, if the breasts are not pulled down into the coil, portions of the breast tissue remain above the coil (arrow) between the chest wall and the center partition of the coil. Because this area is compressed by the patient’s body weight due to prone positioning, the contrast enhancement of the compressed area may be poor. (b) On an axial T1-weighted MR image (4/1) obtained with improved patient positioning, no breast tissue remains above the coil.
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Figure 3. Difficulty of positioning in a woman with large breasts. Sagittal T1-weighted MR image (26/6) of the right breast demonstrates that positioning in the breast coil can be difficult for women with large breasts, which tend to overfill the coil. Deformities are seen where the coil support touches the breast (arrowheads), and signal intensity changes are seen where breast tissue is in proximity to coil elements (arrows).
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Figure 4. Motion artifact. Axial fat-saturated T2-weighted MR image (5210/123) reveals considerable motion blurring along the phase-encoding direction (left to right) due to vessel pulsation. This blurring was present on only a few sections in the series.
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Figure 5a. Misregistration resulting from patient motion. (a) Axial fat-saturated T1-weighted MR image (4/2) obtained following the intravenous administration of gadolinium-based contrast material demonstrates a small spiculated mass (arrow). The mass proved to be invasive ductal carcinoma at core needle biopsy. (b) Subtracted image of the same lesion shows good detail. (c) Axial fat-saturated T1-weighted MR image (4/2) obtained in a different patient following the intravenous administration of gadolinium-based contrast material demonstrates a small, lobular enhancing mass with internal nonenhancing septa (arrow), findings that are consistent with a fibroadenoma. (d) On a subtracted image, the lesion (arrow) is poorly delineated due to misregistration from slight patient motion between pre- and postcontrast sequences (cf c). It is not apparent on this image that the lesion is a fibroadenoma.
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Figure 5b. Misregistration resulting from patient motion. (a) Axial fat-saturated T1-weighted MR image (4/2) obtained following the intravenous administration of gadolinium-based contrast material demonstrates a small spiculated mass (arrow). The mass proved to be invasive ductal carcinoma at core needle biopsy. (b) Subtracted image of the same lesion shows good detail. (c) Axial fat-saturated T1-weighted MR image (4/2) obtained in a different patient following the intravenous administration of gadolinium-based contrast material demonstrates a small, lobular enhancing mass with internal nonenhancing septa (arrow), findings that are consistent with a fibroadenoma. (d) On a subtracted image, the lesion (arrow) is poorly delineated due to misregistration from slight patient motion between pre- and postcontrast sequences (cf c). It is not apparent on this image that the lesion is a fibroadenoma.
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Figure 5c. Misregistration resulting from patient motion. (a) Axial fat-saturated T1-weighted MR image (4/2) obtained following the intravenous administration of gadolinium-based contrast material demonstrates a small spiculated mass (arrow). The mass proved to be invasive ductal carcinoma at core needle biopsy. (b) Subtracted image of the same lesion shows good detail. (c) Axial fat-saturated T1-weighted MR image (4/2) obtained in a different patient following the intravenous administration of gadolinium-based contrast material demonstrates a small, lobular enhancing mass with internal nonenhancing septa (arrow), findings that are consistent with a fibroadenoma. (d) On a subtracted image, the lesion (arrow) is poorly delineated due to misregistration from slight patient motion between pre- and postcontrast sequences (cf c). It is not apparent on this image that the lesion is a fibroadenoma.
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Figure 5d. Misregistration resulting from patient motion. (a) Axial fat-saturated T1-weighted MR image (4/2) obtained following the intravenous administration of gadolinium-based contrast material demonstrates a small spiculated mass (arrow). The mass proved to be invasive ductal carcinoma at core needle biopsy. (b) Subtracted image of the same lesion shows good detail. (c) Axial fat-saturated T1-weighted MR image (4/2) obtained in a different patient following the intravenous administration of gadolinium-based contrast material demonstrates a small, lobular enhancing mass with internal nonenhancing septa (arrow), findings that are consistent with a fibroadenoma. (d) On a subtracted image, the lesion (arrow) is poorly delineated due to misregistration from slight patient motion between pre- and postcontrast sequences (cf c). It is not apparent on this image that the lesion is a fibroadenoma.
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Figure 6a. Metallic artifact in a woman who had undergone prior lumpectomy of the right breast. (a) Axial fat-saturated GRE T2-weighted MR image (5210/123) shows surgical clips at the lumpectomy site creating a local signal intensity void and distortion (arrow). Detection of a small local recurrence may be difficult due to the artifact. (b) Axial fat-saturated T1-weighted MR image (5/1) obtained after intravenous contrast material administration demonstrates an irregular enhancing mass with a small signal intensity void centrally (arrow). Invasive ductal carcinoma had recently been diagnosed at this site with ultrasonography (US)–guided core needle biopsy. The signal intensity void is due to a titanium clip that was placed within the cancer after biopsy. (c) Axial fat-saturated T1-weighted MR image (4/2) of the left breast shows a large signal intensity void (arrow) with distortion (arrowhead) in the lateral breast due to prior percutaneous placement of a stainless steel clip after US-guided core needle biopsy of a benign mass.
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Figure 6b. Metallic artifact in a woman who had undergone prior lumpectomy of the right breast. (a) Axial fat-saturated GRE T2-weighted MR image (5210/123) shows surgical clips at the lumpectomy site creating a local signal intensity void and distortion (arrow). Detection of a small local recurrence may be difficult due to the artifact. (b) Axial fat-saturated T1-weighted MR image (5/1) obtained after intravenous contrast material administration demonstrates an irregular enhancing mass with a small signal intensity void centrally (arrow). Invasive ductal carcinoma had recently been diagnosed at this site with ultrasonography (US)–guided core needle biopsy. The signal intensity void is due to a titanium clip that was placed within the cancer after biopsy. (c) Axial fat-saturated T1-weighted MR image (4/2) of the left breast shows a large signal intensity void (arrow) with distortion (arrowhead) in the lateral breast due to prior percutaneous placement of a stainless steel clip after US-guided core needle biopsy of a benign mass.
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Figure 6c. Metallic artifact in a woman who had undergone prior lumpectomy of the right breast. (a) Axial fat-saturated GRE T2-weighted MR image (5210/123) shows surgical clips at the lumpectomy site creating a local signal intensity void and distortion (arrow). Detection of a small local recurrence may be difficult due to the artifact. (b) Axial fat-saturated T1-weighted MR image (5/1) obtained after intravenous contrast material administration demonstrates an irregular enhancing mass with a small signal intensity void centrally (arrow). Invasive ductal carcinoma had recently been diagnosed at this site with ultrasonography (US)–guided core needle biopsy. The signal intensity void is due to a titanium clip that was placed within the cancer after biopsy. (c) Axial fat-saturated T1-weighted MR image (4/2) of the left breast shows a large signal intensity void (arrow) with distortion (arrowhead) in the lateral breast due to prior percutaneous placement of a stainless steel clip after US-guided core needle biopsy of a benign mass.
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Figure 7. Metallic artifact in a 46-year-old woman who had undergone breast reduction surgery 3 years earlier. Sagittal T1-weighted MR image (26/6) of the right breast shows multiple areas of magnetic susceptibility (arrows) in postoperative areas, including the skin of the inferior breast, inferior breast tissue, and the areola. Mammography did not show any evidence of metal fragments in the breast.
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Figure 8a. Incorrectly sized FOV. (a) Axial T1-weighted MR image (4/2) of both breasts shows the results of using an oversized FOV. (b) Axial T1-weighted MR image (15/4) of the left breast shows the results of using an undersized FOV. The lateral portion of the breast is not visualized, and there is phase wrap artifact from the opposite breast overlying the area of interest (arrows).
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Figure 8b. Incorrectly sized FOV. (a) Axial T1-weighted MR image (4/2) of both breasts shows the results of using an oversized FOV. (b) Axial T1-weighted MR image (15/4) of the left breast shows the results of using an undersized FOV. The lateral portion of the breast is not visualized, and there is phase wrap artifact from the opposite breast overlying the area of interest (arrows).
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Figure 9a. Undersized FOV in the section-select direction. (a) Axial T1-weighted MR image (4/2) representing the first section of the imaging sequence shows fibroglandular breast tissue (arrow), a finding that indicates that the superior portion of the breast was not included in the sequence. (b) On an axial T1-weighted MR image (4/2) from a repeat sequence that was obtained more superior on the chest, no fibroglandular tissue is visualized, a finding that indicates that the entire breast mound is included.
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Figure 9b. Undersized FOV in the section-select direction. (a) Axial T1-weighted MR image (4/2) representing the first section of the imaging sequence shows fibroglandular breast tissue (arrow), a finding that indicates that the superior portion of the breast was not included in the sequence. (b) On an axial T1-weighted MR image (4/2) from a repeat sequence that was obtained more superior on the chest, no fibroglandular tissue is visualized, a finding that indicates that the entire breast mound is included.
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Figure 10a. Use of body coil versus breast coil. (a) Axial T2-weighted MR image (4630/123) obtained with the body coil as the receiver coil is quite noisy because the technologist inadvertently failed to select the breast coil for use. (b) Axial T2-weighted MR image (4630/123) obtained after selecting the breast coil demonstrates considerably decreased noise and improved SNR.
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Figure 10b. Use of body coil versus breast coil. (a) Axial T2-weighted MR image (4630/123) obtained with the body coil as the receiver coil is quite noisy because the technologist inadvertently failed to select the breast coil for use. (b) Axial T2-weighted MR image (4630/123) obtained after selecting the breast coil demonstrates considerably decreased noise and improved SNR.
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Figure 11. Lack of fat saturation in a patient with silicone breast implants. Axial T1-weighted MR image (28/5) demonstrates no suppression of the fat signal intensity, leaving fatty tissues bright (arrows).
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Figure 12a. Inhomogeneous fat saturation. (a) Axial T1-weighted MR image (4/2) shows inhomogeneous fat saturation (arrow). This finding is more common in breasts that are predominantly fatty. (b) Sagittal T1-weighted MR image (26/6) of the right breast obtained in a different patient shows signal flare (arrow) where the breast is near a breast coil element.
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Figure 12b. Inhomogeneous fat saturation. (a) Axial T1-weighted MR image (4/2) shows inhomogeneous fat saturation (arrow). This finding is more common in breasts that are predominantly fatty. (b) Sagittal T1-weighted MR image (26/6) of the right breast obtained in a different patient shows signal flare (arrow) where the breast is near a breast coil element.
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Figure 13. Smearing from incorrect choice of phase-encoding direction. Sagittal T2-weighted MR image (4267/106) of the left breast shows smearing of the image at the lower portion of the breast (arrows), which resulted from phase encoding in the anteroposterior direction. Note that this image was part of a nondiagnostic study and that fat suppression was not used.
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Figure 14. Ghosting from vascular pulsation. Sagittal fat-suppressed T2-weighted MR image (9128/60) of the right breast obtained in a patient with a silicone implant (arrow) shows periodic bright artifacts (arrowheads) due to ghosting of high-signal-intensity blood in a pulsating subclavian vein.
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Figure 15. Ghosting from cardiac motion in a 51-year-old woman who had undergone prior left mastectomy and right lumpectomy. On an axial T1-weighted MR image (4/2), one of the right serratus anterior muscles (arrow) has higher signal intensity than the surrounding muscle tissue. This hyperintensity could be mistaken for possible involvement with cancer but is actually due to ghosting along the phase-encoding direction from cardiac motion.
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Figure 17a. Wraparound artifact due to a breast coil. (a) Axial fat-suppressed T1-weighted MR image (4/2) shows medium-signal-intensity artifact (single arrows) on the upper part of the image. Because the patient is prone, this artifact represents part of the breast coil. This phenomenon can occur with collected moisture in the coil structure. Dotted line and double arrow indicate the center partition of the coil. (b) Axial fat-suppressed T1-weighted MR image (4/2) obtained in a different patient shows the same type of artifact (single arrows) overlying the breast tissue due to larger breast size. The artifact is the same distance from the center partition of the coil (dotted line and double arrow) as it is in a, and will, in fact, occur at the same distance from the center partition in all cases.
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Figure 17b. Wraparound artifact due to a breast coil. (a) Axial fat-suppressed T1-weighted MR image (4/2) shows medium-signal-intensity artifact (single arrows) on the upper part of the image. Because the patient is prone, this artifact represents part of the breast coil. This phenomenon can occur with collected moisture in the coil structure. Dotted line and double arrow indicate the center partition of the coil. (b) Axial fat-suppressed T1-weighted MR image (4/2) obtained in a different patient shows the same type of artifact (single arrows) overlying the breast tissue due to larger breast size. The artifact is the same distance from the center partition of the coil (dotted line and double arrow) as it is in a, and will, in fact, occur at the same distance from the center partition in all cases.
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Figure 18. Three-dimensional phase wrap artifact. Sagittal T2-weighted MR image (4/2) of the left breast obtained with a 3D volume sequence demonstrates 3D phase wrap artifact (arrows) in the section-select direction. The artifact appears as a ghostlike outline of signal-producing breast tissues.
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Figure 19. Zebra artifact. Axial T1-weighted MR image (5/2) obtained with a body coil shows concentric rings of high and low signal intensity (arrowhead), a finding that is consistent with zebra (moiré) artifact. Poor shimming caused inhomogeneous fat saturation; the fat appears dark on the lateral portions of the right breast and bright on the left breast (open arrow). Image wrap (solid arrows) occurred in the phase-encoding direction because signal-producing tissues were excluded from the selected FOV. The zebra artifact is the result of a phase shift across the image, likely due in this case to both poor shimming and image wrap of signal-producing tissues. The phase difference between tissues included in the selected FOV and tissues wrapping into the image cause the light-dark banding.
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Figure 20. RF interference artifact. (20) Axial T2-weighted MR image (5210/123) demonstrates multiple high-signal-intensity bands (arrows) in the phase-encoding direction due to external RF noise. The door to the imaging room had not been completely shut, allowing external RF noise to leak into the room during imaging.
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Figure 21a. (21a) Axial T1-weighted MR image (4/2) demonstrates a linear high-signal-intensity band overlying the right breast (arrows) due to RF noise occurring at a particular frequency within the bandwidth of the acquired image. The RF artifact propagates in the phase-encoding direction, which is left to right on this image. (21b) Photograph shows damage to the copper seal (arrows) on the door to the imaging room. This damage proved to be the cause of the RF leak.
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Figure 21b. (21a) Axial T1-weighted MR image (4/2) demonstrates a linear high-signal-intensity band overlying the right breast (arrows) due to RF noise occurring at a particular frequency within the bandwidth of the acquired image. The RF artifact propagates in the phase-encoding direction, which is left to right on this image. (21b) Photograph shows damage to the copper seal (arrows) on the door to the imaging room. This damage proved to be the cause of the RF leak.
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Figure 22. Zipper artifact. Axial fat-suppressed T2-weighted MR image (9000/67) shows a band of small high-signal-intensity foci (arrowheads). The band was located in the center of the original image (measuring from top to bottom), a finding that is characteristic of zipper artifact. The high-signal-intensity area in the left breast (arrow) represents a silicone implant.
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Figure 23a. Chemical shift artifact. GRE MR imaging was performed to demonstrate the effects of varying the echo time and bandwidth on chemical shift artifacts. (a) On a sagittal GRE MR image (200/7) of the right breast obtained at a typical intermediate bandwidth of 81.4 Hz/pixel, the bandwidth produces a water-fat displacement of 2.8 pixels in the horizontal (anteroposterior) direction. The echo time (7 mm) is such that, in GRE imaging, water and fat are out of phase, producing a black border at all water-fat interfaces. (b) Sagittal GRE MR image (200/7) obtained at a lower bandwidth (23.3 Hz/pixel) shows a water-fat displacement of 9.6 pixels. (c) On a sagittal GRE MR image (200/9) obtained at the same intermediate bandwidth as a, the pixel shift between water and fat is 2.8 pixels left to right. At this echo time (9 mm), water and fat are nearly in phase. The displacement of fat relative to water produces a bright band where water and fat overlap and a dark band where water and fat are shifted apart. (d) On a sagittal GRE MR image (200/9) obtained at a lower bandwidth of 15.8 Hz/pixel, fat and water are again nearly in phase, but the lower bandwidth causes a fat-water displacement of 14.1 pixels, creating wider bright bands where fat and water overlap and wider dark bands where fat and water are shifted apart (cf c).
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Figure 23b. Chemical shift artifact. GRE MR imaging was performed to demonstrate the effects of varying the echo time and bandwidth on chemical shift artifacts. (a) On a sagittal GRE MR image (200/7) of the right breast obtained at a typical intermediate bandwidth of 81.4 Hz/pixel, the bandwidth produces a water-fat displacement of 2.8 pixels in the horizontal (anteroposterior) direction. The echo time (7 mm) is such that, in GRE imaging, water and fat are out of phase, producing a black border at all water-fat interfaces. (b) Sagittal GRE MR image (200/7) obtained at a lower bandwidth (23.3 Hz/pixel) shows a water-fat displacement of 9.6 pixels. (c) On a sagittal GRE MR image (200/9) obtained at the same intermediate bandwidth as a, the pixel shift between water and fat is 2.8 pixels left to right. At this echo time (9 mm), water and fat are nearly in phase. The displacement of fat relative to water produces a bright band where water and fat overlap and a dark band where water and fat are shifted apart. (d) On a sagittal GRE MR image (200/9) obtained at a lower bandwidth of 15.8 Hz/pixel, fat and water are again nearly in phase, but the lower bandwidth causes a fat-water displacement of 14.1 pixels, creating wider bright bands where fat and water overlap and wider dark bands where fat and water are shifted apart (cf c).
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Figure 23c. Chemical shift artifact. GRE MR imaging was performed to demonstrate the effects of varying the echo time and bandwidth on chemical shift artifacts. (a) On a sagittal GRE MR image (200/7) of the right breast obtained at a typical intermediate bandwidth of 81.4 Hz/pixel, the bandwidth produces a water-fat displacement of 2.8 pixels in the horizontal (anteroposterior) direction. The echo time (7 mm) is such that, in GRE imaging, water and fat are out of phase, producing a black border at all water-fat interfaces. (b) Sagittal GRE MR image (200/7) obtained at a lower bandwidth (23.3 Hz/pixel) shows a water-fat displacement of 9.6 pixels. (c) On a sagittal GRE MR image (200/9) obtained at the same intermediate bandwidth as a, the pixel shift between water and fat is 2.8 pixels left to right. At this echo time (9 mm), water and fat are nearly in phase. The displacement of fat relative to water produces a bright band where water and fat overlap and a dark band where water and fat are shifted apart. (d) On a sagittal GRE MR image (200/9) obtained at a lower bandwidth of 15.8 Hz/pixel, fat and water are again nearly in phase, but the lower bandwidth causes a fat-water displacement of 14.1 pixels, creating wider bright bands where fat and water overlap and wider dark bands where fat and water are shifted apart (cf c).
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Figure 23d. Chemical shift artifact. GRE MR imaging was performed to demonstrate the effects of varying the echo time and bandwidth on chemical shift artifacts. (a) On a sagittal GRE MR image (200/7) of the right breast obtained at a typical intermediate bandwidth of 81.4 Hz/pixel, the bandwidth produces a water-fat displacement of 2.8 pixels in the horizontal (anteroposterior) direction. The echo time (7 mm) is such that, in GRE imaging, water and fat are out of phase, producing a black border at all water-fat interfaces. (b) Sagittal GRE MR image (200/7) obtained at a lower bandwidth (23.3 Hz/pixel) shows a water-fat displacement of 9.6 pixels. (c) On a sagittal GRE MR image (200/9) obtained at the same intermediate bandwidth as a, the pixel shift between water and fat is 2.8 pixels left to right. At this echo time (9 mm), water and fat are nearly in phase. The displacement of fat relative to water produces a bright band where water and fat overlap and a dark band where water and fat are shifted apart. (d) On a sagittal GRE MR image (200/9) obtained at a lower bandwidth of 15.8 Hz/pixel, fat and water are again nearly in phase, but the lower bandwidth causes a fat-water displacement of 14.1 pixels, creating wider bright bands where fat and water overlap and wider dark bands where fat and water are shifted apart (cf c).
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Copyright © 2007 by the Radiological Society of North America.
