Golden-angle Radial stack-of-stars VIBEシーケンスを用いた直腸癌の動的造影MR画像：従来の造影3D VIBEシーケンスとの比較

Dynamic contrast-enhanced MR imaging of rectal cancer using a golden-angle radial stack-of-stars VIBE sequence: comparison with conventional contrast-enhanced 3D VIBE sequence.

抄録

目的:

直腸癌患者において、従来の3D volumetric-interpolated breath-hold examination（C-VIBE）シーケンスの画質をgolden-angle radial stack-of-stars acquisition scheme（R-VIBE）シーケンスの画質と比較する。

PURPOSE: To compare conventional 3D volumetric-interpolated breath-hold examination (C-VIBE) sequence image quality to that of golden-angle radial stack-of stars acquisition scheme (R-VIBE) in rectal cancer patients.

方法:

78名の直腸癌患者を対象に、造影前C-VIBE、R-VIBEによるDCE-MRI、造影後C-VIBEを施行した。R-VIBEシーケンスの最初のフェーズと最後のフェーズを、それぞれ造影前C-VIBEシーケンスと造影後C-VIBEシーケンスと比較した。直腸新生物、大殿筋、皮下脂肪の信号対雑音比（SNR）とコントラスト対雑音比（CNR）を2つの異なるシーケンス間で比較した。さらに定性的なスコアシステム（1-5で評価）を用いて画像全体を評価した。2つのシーケンスから得られた定量的および定性的パラメータを比較した。

METHODS: Seventy-eight patients had undergone pre-contrast C-VIBE, followed by DCE-MRI with R-VIBE and post-contrast C-VIBE in the visualization of rectal cancer. The first phase and the last phase of R-VIBE sequence were compared with pre-contrast and post-contrast C-VIBE sequences, respectively. Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of rectal neoplasms, gluteus maximus, and subcutaneous fat were compared between the two different sequences. A further qualitative score system (graded 1-5) was used to evaluate the overall image. Quantitative and qualitative parameters from the two sequences were compared.

結果:

すべての患者において、R-VIBEは造影前と造影後で同じSNRとCNRの評価を得たが（すべてP>0.05）、造影前画像では脂肪のSNRが高かった（P=0.037）。さらに、全体的な画質、病変の明瞭性、直腸壁の境界のスコアにも有意差はなかった（すべてP>0.05）。造影後R-VIBEシーケンスのアーチファクトのスコアは改善した（P=0.005）。

RESULTS: In all patients, R-VIBE achieved the same SNR and CNR ratings in pre- and post-contrast (all P > 0.05), with the exception of a higher SNR of fat in pre-contrast images (P = 0.037). In addition, there were no significant differences in scores of overall image quality, lesion conspicuity, and rectal wall boundary (all P > 0.05). There was an improved score in artifacts of post-contrast R-VIBE sequence (P = 0.005).

結論:

R-VIBEシーケンスはC-VIBEシーケンスに匹敵する画質と少ないモーションアーチファクトを提供することができ、直腸癌の撮像に実行可能である。

CONCLUSION: R-VIBE sequence can provide comparable image quality and less motion artifacts to that of C-VIBE sequence and is feasible for imaging of rectal cancer.