SEMAC-VAT and MSVAT-SPACE sequence strategies for metal artifact reduction in 1.5T magnetic resonance imaging

Tao Ai, Abraham Padua, Frank Goerner, Mathias Nittka, Zbigniew Gugala, Siddharth Jadhav, Miguel Trelles, Raleigh F. Johnson, Ronald Lindsey, Xiaoming Li, Val M. Runge

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

Objectives: To evaluate the ability of four magnetic resonance imaging (MRI) techniques to correct for metallic artifacts. These techniques consisted of 3 2D techniques and one 3D technique. In 2D imaging the techniques View Angle Tilting (VAT), Slice Encoding for Metal Artifact Correction (SEMAC) and a technique that employed a combination of the first two (SEMAC-VAT) were evaluated. In 3D imaging the technique Multiple Slab acquisition with VAT based on a SPACE sequence was evaluated (MSVAT-SPACE). Materials and Methods: Agarose phantoms and tissue phantoms with two commonly used metal implants (stainless steel and titanium) as well as two volunteers with metal implants were imaged at 1.5T. All phantoms and volunteers were imaged using VAT, SEMAC, SEMAC-VAT and MSVAT-SPACE techniques, as well as 2D and 3D conventional imaging techniques. Each technique was optimized for different image contrast mechanisms. Artifact reduction was quantitatively assessed in the agarose phantoms by volumetric measurement. Image quality was qualitatively assessed by blinded reads employing two readers. Each reader independently viewed the tissue phantom images and in vivo human images. Statistical analysis was performed using a Friedman test, Wilcoxon test and weighted Cohen's kappa test. Results: T1-weighted, T2-weighted, PD-weighted and STIR image contrasts were successfully implemented with the evaluated artifact reduction sequences in both the phantom experiments and in vivo images. For all evaluated image contrasts and both metal implants, a reduction in the volume of metal artifacts was seen when compared with 2D conventional acquisitions. The 2D metal artifact volumes on average were reduced by 49% ± 16%, 56% ± 15% and 63% ± 15% for VAT, SEMAC and SEMAC-VAT acquisitions respectively. When Friedman and Wilcoxon tests were applied the difference in metal artifact volume was found to be statistically significant when VAT, SEMAC and SEMAC-VAT were compared with the 2D conventional techniques. In 3D imaging on average MSVAT-SPACE reduced metal artifact volume compared with the 3D conventional imaging technique by 72% ± 23% for all evaluated image contrasts and both metal implants. The metal artifact volume differences were statistically significant when MSVAT-SPACE was compared with the 3D conventional technique. The blinded reads demonstrated that SEMAC-VAT and MSVAT-SPACE had distinctly superior quality compared with conventional acquisitions. Quality was measured in terms of artifact size, distortions, image quality and visualization of bone marrow and soft tissues adjacent to metal implants. This was the case for both tissue phantom images and human images with good interobserver agreement. Conclusions: SEMAC-VAT (2D) and MSVAT-SPACE (3D) demonstrated a consistent, marked reduction of metal artifacts for different metal implants and offered flexible image contrasts (T1, T2, PD and STIR) with high image quality. These techniques likely will improve the evaluation of postoperative patients with metal implants.

Original languageEnglish (US)
Pages (from-to)267-276
Number of pages10
JournalInvestigative Radiology
Volume47
Issue number5
DOIs
StatePublished - May 2012

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Artifacts
Metals
Magnetic Resonance Imaging
Sepharose
Volunteers
Stainless Steel

Keywords

  • magnetic resonance imaging
  • metal artifact reduction
  • MSVAT-SPACE
  • orthopedic implants
  • SEMAC
  • SEMAC-VAT
  • stainless steel
  • titanium
  • VAT
  • view angle tilting

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this

SEMAC-VAT and MSVAT-SPACE sequence strategies for metal artifact reduction in 1.5T magnetic resonance imaging. / Ai, Tao; Padua, Abraham; Goerner, Frank; Nittka, Mathias; Gugala, Zbigniew; Jadhav, Siddharth; Trelles, Miguel; Johnson, Raleigh F.; Lindsey, Ronald; Li, Xiaoming; Runge, Val M.

In: Investigative Radiology, Vol. 47, No. 5, 05.2012, p. 267-276.

Research output: Contribution to journalArticle

Ai, T, Padua, A, Goerner, F, Nittka, M, Gugala, Z, Jadhav, S, Trelles, M, Johnson, RF, Lindsey, R, Li, X & Runge, VM 2012, 'SEMAC-VAT and MSVAT-SPACE sequence strategies for metal artifact reduction in 1.5T magnetic resonance imaging', Investigative Radiology, vol. 47, no. 5, pp. 267-276. https://doi.org/10.1097/RLI.0b013e318240a919
Ai, Tao ; Padua, Abraham ; Goerner, Frank ; Nittka, Mathias ; Gugala, Zbigniew ; Jadhav, Siddharth ; Trelles, Miguel ; Johnson, Raleigh F. ; Lindsey, Ronald ; Li, Xiaoming ; Runge, Val M. / SEMAC-VAT and MSVAT-SPACE sequence strategies for metal artifact reduction in 1.5T magnetic resonance imaging. In: Investigative Radiology. 2012 ; Vol. 47, No. 5. pp. 267-276.
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abstract = "Objectives: To evaluate the ability of four magnetic resonance imaging (MRI) techniques to correct for metallic artifacts. These techniques consisted of 3 2D techniques and one 3D technique. In 2D imaging the techniques View Angle Tilting (VAT), Slice Encoding for Metal Artifact Correction (SEMAC) and a technique that employed a combination of the first two (SEMAC-VAT) were evaluated. In 3D imaging the technique Multiple Slab acquisition with VAT based on a SPACE sequence was evaluated (MSVAT-SPACE). Materials and Methods: Agarose phantoms and tissue phantoms with two commonly used metal implants (stainless steel and titanium) as well as two volunteers with metal implants were imaged at 1.5T. All phantoms and volunteers were imaged using VAT, SEMAC, SEMAC-VAT and MSVAT-SPACE techniques, as well as 2D and 3D conventional imaging techniques. Each technique was optimized for different image contrast mechanisms. Artifact reduction was quantitatively assessed in the agarose phantoms by volumetric measurement. Image quality was qualitatively assessed by blinded reads employing two readers. Each reader independently viewed the tissue phantom images and in vivo human images. Statistical analysis was performed using a Friedman test, Wilcoxon test and weighted Cohen's kappa test. Results: T1-weighted, T2-weighted, PD-weighted and STIR image contrasts were successfully implemented with the evaluated artifact reduction sequences in both the phantom experiments and in vivo images. For all evaluated image contrasts and both metal implants, a reduction in the volume of metal artifacts was seen when compared with 2D conventional acquisitions. The 2D metal artifact volumes on average were reduced by 49{\%} ± 16{\%}, 56{\%} ± 15{\%} and 63{\%} ± 15{\%} for VAT, SEMAC and SEMAC-VAT acquisitions respectively. When Friedman and Wilcoxon tests were applied the difference in metal artifact volume was found to be statistically significant when VAT, SEMAC and SEMAC-VAT were compared with the 2D conventional techniques. In 3D imaging on average MSVAT-SPACE reduced metal artifact volume compared with the 3D conventional imaging technique by 72{\%} ± 23{\%} for all evaluated image contrasts and both metal implants. The metal artifact volume differences were statistically significant when MSVAT-SPACE was compared with the 3D conventional technique. The blinded reads demonstrated that SEMAC-VAT and MSVAT-SPACE had distinctly superior quality compared with conventional acquisitions. Quality was measured in terms of artifact size, distortions, image quality and visualization of bone marrow and soft tissues adjacent to metal implants. This was the case for both tissue phantom images and human images with good interobserver agreement. Conclusions: SEMAC-VAT (2D) and MSVAT-SPACE (3D) demonstrated a consistent, marked reduction of metal artifacts for different metal implants and offered flexible image contrasts (T1, T2, PD and STIR) with high image quality. These techniques likely will improve the evaluation of postoperative patients with metal implants.",
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author = "Tao Ai and Abraham Padua and Frank Goerner and Mathias Nittka and Zbigniew Gugala and Siddharth Jadhav and Miguel Trelles and Johnson, {Raleigh F.} and Ronald Lindsey and Xiaoming Li and Runge, {Val M.}",
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TY - JOUR

T1 - SEMAC-VAT and MSVAT-SPACE sequence strategies for metal artifact reduction in 1.5T magnetic resonance imaging

AU - Ai, Tao

AU - Padua, Abraham

AU - Goerner, Frank

AU - Nittka, Mathias

AU - Gugala, Zbigniew

AU - Jadhav, Siddharth

AU - Trelles, Miguel

AU - Johnson, Raleigh F.

AU - Lindsey, Ronald

AU - Li, Xiaoming

AU - Runge, Val M.

PY - 2012/5

Y1 - 2012/5

N2 - Objectives: To evaluate the ability of four magnetic resonance imaging (MRI) techniques to correct for metallic artifacts. These techniques consisted of 3 2D techniques and one 3D technique. In 2D imaging the techniques View Angle Tilting (VAT), Slice Encoding for Metal Artifact Correction (SEMAC) and a technique that employed a combination of the first two (SEMAC-VAT) were evaluated. In 3D imaging the technique Multiple Slab acquisition with VAT based on a SPACE sequence was evaluated (MSVAT-SPACE). Materials and Methods: Agarose phantoms and tissue phantoms with two commonly used metal implants (stainless steel and titanium) as well as two volunteers with metal implants were imaged at 1.5T. All phantoms and volunteers were imaged using VAT, SEMAC, SEMAC-VAT and MSVAT-SPACE techniques, as well as 2D and 3D conventional imaging techniques. Each technique was optimized for different image contrast mechanisms. Artifact reduction was quantitatively assessed in the agarose phantoms by volumetric measurement. Image quality was qualitatively assessed by blinded reads employing two readers. Each reader independently viewed the tissue phantom images and in vivo human images. Statistical analysis was performed using a Friedman test, Wilcoxon test and weighted Cohen's kappa test. Results: T1-weighted, T2-weighted, PD-weighted and STIR image contrasts were successfully implemented with the evaluated artifact reduction sequences in both the phantom experiments and in vivo images. For all evaluated image contrasts and both metal implants, a reduction in the volume of metal artifacts was seen when compared with 2D conventional acquisitions. The 2D metal artifact volumes on average were reduced by 49% ± 16%, 56% ± 15% and 63% ± 15% for VAT, SEMAC and SEMAC-VAT acquisitions respectively. When Friedman and Wilcoxon tests were applied the difference in metal artifact volume was found to be statistically significant when VAT, SEMAC and SEMAC-VAT were compared with the 2D conventional techniques. In 3D imaging on average MSVAT-SPACE reduced metal artifact volume compared with the 3D conventional imaging technique by 72% ± 23% for all evaluated image contrasts and both metal implants. The metal artifact volume differences were statistically significant when MSVAT-SPACE was compared with the 3D conventional technique. The blinded reads demonstrated that SEMAC-VAT and MSVAT-SPACE had distinctly superior quality compared with conventional acquisitions. Quality was measured in terms of artifact size, distortions, image quality and visualization of bone marrow and soft tissues adjacent to metal implants. This was the case for both tissue phantom images and human images with good interobserver agreement. Conclusions: SEMAC-VAT (2D) and MSVAT-SPACE (3D) demonstrated a consistent, marked reduction of metal artifacts for different metal implants and offered flexible image contrasts (T1, T2, PD and STIR) with high image quality. These techniques likely will improve the evaluation of postoperative patients with metal implants.

AB - Objectives: To evaluate the ability of four magnetic resonance imaging (MRI) techniques to correct for metallic artifacts. These techniques consisted of 3 2D techniques and one 3D technique. In 2D imaging the techniques View Angle Tilting (VAT), Slice Encoding for Metal Artifact Correction (SEMAC) and a technique that employed a combination of the first two (SEMAC-VAT) were evaluated. In 3D imaging the technique Multiple Slab acquisition with VAT based on a SPACE sequence was evaluated (MSVAT-SPACE). Materials and Methods: Agarose phantoms and tissue phantoms with two commonly used metal implants (stainless steel and titanium) as well as two volunteers with metal implants were imaged at 1.5T. All phantoms and volunteers were imaged using VAT, SEMAC, SEMAC-VAT and MSVAT-SPACE techniques, as well as 2D and 3D conventional imaging techniques. Each technique was optimized for different image contrast mechanisms. Artifact reduction was quantitatively assessed in the agarose phantoms by volumetric measurement. Image quality was qualitatively assessed by blinded reads employing two readers. Each reader independently viewed the tissue phantom images and in vivo human images. Statistical analysis was performed using a Friedman test, Wilcoxon test and weighted Cohen's kappa test. Results: T1-weighted, T2-weighted, PD-weighted and STIR image contrasts were successfully implemented with the evaluated artifact reduction sequences in both the phantom experiments and in vivo images. For all evaluated image contrasts and both metal implants, a reduction in the volume of metal artifacts was seen when compared with 2D conventional acquisitions. The 2D metal artifact volumes on average were reduced by 49% ± 16%, 56% ± 15% and 63% ± 15% for VAT, SEMAC and SEMAC-VAT acquisitions respectively. When Friedman and Wilcoxon tests were applied the difference in metal artifact volume was found to be statistically significant when VAT, SEMAC and SEMAC-VAT were compared with the 2D conventional techniques. In 3D imaging on average MSVAT-SPACE reduced metal artifact volume compared with the 3D conventional imaging technique by 72% ± 23% for all evaluated image contrasts and both metal implants. The metal artifact volume differences were statistically significant when MSVAT-SPACE was compared with the 3D conventional technique. The blinded reads demonstrated that SEMAC-VAT and MSVAT-SPACE had distinctly superior quality compared with conventional acquisitions. Quality was measured in terms of artifact size, distortions, image quality and visualization of bone marrow and soft tissues adjacent to metal implants. This was the case for both tissue phantom images and human images with good interobserver agreement. Conclusions: SEMAC-VAT (2D) and MSVAT-SPACE (3D) demonstrated a consistent, marked reduction of metal artifacts for different metal implants and offered flexible image contrasts (T1, T2, PD and STIR) with high image quality. These techniques likely will improve the evaluation of postoperative patients with metal implants.

KW - magnetic resonance imaging

KW - metal artifact reduction

KW - MSVAT-SPACE

KW - orthopedic implants

KW - SEMAC

KW - SEMAC-VAT

KW - stainless steel

KW - titanium

KW - VAT

KW - view angle tilting

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