Magnetic Resonance Imaging Metallic Artifact of Commonly Encountered Surgical Implants and Foreign Material

Sutherland‐Smith, James; Tilley, Brenda

doi:10.1111/j.1740-8261.2011.01916.x

Cited by 11 publications

(18 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…There are several disadvantages and limitations of the T2* sequence: it has an inherently low signal‐to‐noise ratio, which likely accounts for the inability to discern some of the parenchymal lesions seen on T2 and FLAIR in this study; any para‐ or ferromagnetic material or air‐brain interfaces near the field of view will result in marked susceptibility artifact, which can impair interpretation or even render the sequence nondiagnostic, as occurred in one of the cases in this study , . In addition, the susceptibility artifact can “bloom,” making the size or internal characteristics of a lesion difficult to determine, and it is often not possible to accurately age a hemorrhagic lesion based on T2*‐weighted images since there can be overlap among the appearances of different stages of hemorrhage on T2* .…”

Section: Discussionmentioning

confidence: 94%

“…There are several disadvantages and limitations of the T2 * sequence: it has an inherently low signal-to-noise ratio, which likely accounts for the inability to discern some of the parenchymal lesions seen on T2 and FLAIR in this study; any para-or ferromagnetic material or air-brain interfaces near the field of view will result in marked susceptibility artifact, which can impair interpretation or even render the sequence nondiagnostic, as occurred in one of the cases in this study. 23,24,[65][66][67] In addition, the susceptibility artifact can "bloom," making the size or internal characteristics of a lesion difficult to determine, and it is often not possible to accurately age a hemorrhagic lesion based on T2 * -weighted images since there can be overlap among the appearances of different stages of hemorrhage on T2 * . 23,68 An additional problem encountered with the T2 * -weighted gradient recalled echo sequence was misinterpretation of normal structures as pseudolesions, leading to the conclusion that subtle parenchymal changes not associated with susceptibility artifact on T2 * -weighted images should be interpreted with caution and should always be compared to sequences with better soft tissue contrast and signal-tonoise ratio.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Use of the T2*‐weighted Gradient Recalled Echo Sequence for Magnetic Resonance Imaging of the Canine and Feline Brain

Hodshon

Hecht

Thomas

2014

Vet Radiology Ultrasound

View full text Add to dashboard Cite

T2*-weighted magnetic resonance imaging (MRI) has been reported to help improve detection of intracranial hemorrhage and is widely used in human neuroimaging. To assess the utility of this technique in small animals, interpretations based on this sequence were compared with those based on paired T2-weighted and fluid-attenuated inversion recovery (FLAIR) sequences in 200 dogs and cats that underwent brain MRI for suspected intracranial disease. Two sets of images (T2 + FLAIR and T2*) were reviewed separately in random order unaccompanied by patient information and were interpreted as normal or abnormal based on whether intracranial abnormalities were seen. The number and location of intracranial lesions were recorded. Eighty-five studies were considered normal and 88 were considered abnormal based on both sets of images, with good agreement (κ = 0.731) between the two. Susceptibility artifact was present in 33 cases (16.5%) on T2*-weighted images. In 12 cases (6%) a total of 69 lesions were seen on T2*-weighted images that were not seen on T2/FLAIR, all of which were associated with susceptibility artifact caused by presumed intracranial hemorrhage. Pseudolesions were seen on T2*-weighted images in five cases, none of which were associated with susceptibility artifact. Abnormalities were seen on T2/FLAIR images that were not seen on T2*-weighted images in 35 cases, confirming that T2* does not replace standard spin echo sequences. These results support inclusion of T2*-weighted sequences in small animal brain MRI studies and indicate that that a large number of abnormalities (especially hemorrhagic lesions) can go undetected if it is not performed.

show abstract

Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Use of the T2*‐weighted Gradient Recalled Echo Sequence for Magnetic Resonance Imaging of the Canine and Feline Brain

Hodshon

Hecht

Thomas

2014

Vet Radiology Ultrasound

View full text Add to dashboard Cite

show abstract

“…For example, metallic structures may result in artifacts such as geometrical distortion, central areas of signal loss, and peripheral linear hyperintensities due to differences in magnetic susceptibility between normal tissue and implant. [12][13][14] Tantalum cages are known to produce drastically less distortion of MR images than stainless steel or titanium implants because they have lower magnetic susceptibility. Although previous authors have suggested that this artifact is negligible, our experience has been different, particularly at the surgical level (Fig.…”

mentioning

confidence: 99%

Magnetic resonance imaging artifact following anterior cervical discectomy and fusion with a trabecular metal cage

Elliott¹,

Fox

Ashforth

et al. 2016

SPI

View full text Add to dashboard Cite

OBJECT This study was undertaken to evaluate the impact of postoperative MRI artifact on the assessment of ongoing spinal cord or nerve root compression after anterior cervical discectomy and fusion (ACDF) using a trabecular tantalum cage or bone autograft or allograft. METHODS The authors conducted a retrospective review of postoperative MRI studies of patients treated surgically for cervical disc degenerative disease or cervical instability secondary to trauma. Standard ACDF with either a trabecular tantalum cage or interbody bone graft had been performed. Postoperative MR images were shown twice in random order to each of 3 assessors (2 spine surgeons, 1 neuroradiologist) to determine whether the presence of a tantalum interbody cage and/or anterior cervical fixation plate or screws imparted MRI artifact significant enough to prevent reliable postoperative assessment of ongoing spinal cord or nerve root compression. RESULTS A total of 63 patients were identified. One group of 29 patients received a tantalum interbody cage, with 13 patients (45%) undergoing anterior plate fixation. A second group of 34 patients received bone auto- or allograft, with 23 (68%) undergoing anterior plate fixation. The paramagnetic implant construct artifact had minimal impact on visualization of postoperative surgical level spinal cord compression. In the cage group, 98% (171/174) of the cases were rated as assessable versus 99% in the bone graft group (201/204), with high intraobserver reliability. In contrast, for the assessment of ongoing surgical level nerve root compression, the presence of a tantalum cage significantly decreased visualization of nerve roots to 70% (121/174) in comparison with 85% (173/204) in the bone graft group (p < 0.001). When sequences using turbo spin echo (TSE), a T2-weighted axial sequence, were acquired, nerve roots were rated as assessable in 88% (69/78) of cases; when only axial T2-weighted sequences were available, the nerve roots were rated as assessable in 54% (52/96) of cases (p < 0.01). The presence of anterior plate fixation had minimal impact on visualization of the spinal cord (99% [213/216] for plated cases vs 98% [159/162] for nonplated cases; p = 1.0) or nerve roots (79% [170/216] for plated cases vs 77% [124/162] for nonplated cases; p = 0.62). CONCLUSIONS Interbody fusion with tantalum cage following anterior cervical discectomy imparts significant paramagnetic artifact, which significantly decreases visualization and assessment of ongoing surgical level nerve root, but not spinal cord, compression. Anterior plate constructs do not affect visualization of these structures. TSE T2-weighted sequences significantly improve nerve root visualization and should be performed as part of a standard postoperative protocol when imaging the cervical spine following interbody implantation of materials with potential for paramagnetic artifact.

show abstract

“…Einfluss der Phasen-/Frequenzkodierung: Wird die Phasenkodierung in y-Richtung (Frequenzkodierung in z-Richtung) und vertikal zur Längsachse des metallischen Objekts gewählt, können größere Suszeptibilitätsartefakte verursacht werden (2,31,32). Mit der dreidimensionalen Messmethode ließ sich dies bei SE-Sequenzen nachvollziehen.…”

Section: Diskussionunclassified

Größenvergleich von Suszeptibilitätsartefakten verursacht durch Mikrochips unterschiedlicher Geometrie am 1,5-Tesla-Magnetresonanztomographen

Dengg¹,

Kneissl²

2013

Tierarztl Prax Ausg K

View full text Add to dashboard Cite

Zusammenfassung Gegenstand und Ziel: Ferromagnetisches Material als Bestandteil eines Mikrochips zur Tierkennzeichnung verursacht in der Magnetresonanztomographie lokale Signalanhebungen, Bildauslöschungen und -verzerrungen (Suszeptibilitätsartefakte). Ziel dieser Studie war, den Einfluss unterschiedlicher Mikrochipgeometrie auf die Größe der Suszeptibilitätsartefakt standardisiert zu prüfen. Material und Methode: Mikrochips der Marken Datamars®, Euro-I.D.® und Planet-ID® (n = 15) wurden nacheinander in ein Messphantom eingebracht und unter Berücksichtigung der ASTM-Standardtestmethode F2119–07 (Spinecho [TR 500 ms, TE 20 ms], Gradientenecho [TR 300 ms, TE 15 ms, Kippwinkel 30°], Schichtdicke 3 mm, Field of View 250 x 250 mm, Akquisitionsmatrix 256 x 256 Pixel, Bandbreite 32 kHz) bei 1,5 Tesla untersucht. Die Bildakquisition erfolgte jeweils mit einer Mikrochiplage in x- und z-Richtung sowie einer Phasenkodierung in y- und z-Richtung. Die Artefaktgröße wurde mittels a) Messung laut Testmethode F2119–07 unter Zuhilfenahme eines homogenen Punktoperators, b) Signalintensitätsmessung nach Matsuura et al. und c) Zählen der Pixel im Artefakt nach Port und Pomper ermittelt. Ergebnisse: Für die drei Mikrochips ergaben sich bei allen drei Messmethoden signifikante Unterschiede hinsichtlich der Artefaktgröße (Wilcoxon p = 0,032). Bei einer Zunahme des Mikrochipvolumens um das Zweibis Dreifache vergrößerte sich das Artefakt um bis zu 76%, je nach Sequenztechnik, Phasenkodierung und Chiplage zu B0. Schlussfolgerungen und klinische Relevanz: Je kleiner die Chipgeometrie, desto geringer das Suszeptibilitätsartefakt. Spinechos (SE) verursachen kleinere Artefakte als Gradientenechos (GE). Die Änderung der Phasenkodierung hat bei dreidimensionaler Messung des Artefakts bei GESequenzen eine geringere Auswirkung auf die Artefaktgröße als bei SE-Sequenzen. Allerdings kann dadurch bei Letzteren die Artefaktform und -richtung beeinflusst werden. Die Größe des durch den Mikrochip verursachten Artefakts spielt für die Bildauswertung der MRT-Untersuchung im Bereich Kopf, Hals und Schulter eine wesentliche klinische Rolle.

show abstract

Magnetic Resonance Imaging Metallic Artifact of Commonly Encountered Surgical Implants and Foreign Material

Cited by 11 publications

References 19 publications

Use of the T2*‐weighted Gradient Recalled Echo Sequence for Magnetic Resonance Imaging of the Canine and Feline Brain

Use of the T2*‐weighted Gradient Recalled Echo Sequence for Magnetic Resonance Imaging of the Canine and Feline Brain

Magnetic resonance imaging artifact following anterior cervical discectomy and fusion with a trabecular metal cage

Größenvergleich von Suszeptibilitätsartefakten verursacht durch Mikrochips unterschiedlicher Geometrie am 1,5-Tesla-Magnetresonanztomographen

Contact Info

Product

Resources

About