Arts and Sciences ATP Tagging MRI Wall motion evaluation of the ischemic myocardium using the adenosine triphosphate medication Tagging MRI 1 52330 2 1 53751 1 1 1 56568 1 18674 1 22485 1 2 Key words: magnetic resonance imaging; ATP; myocardial perfusion imaging; myocardial infarction; tagging. Tagging MRI ATP Tagging MRI C-strain C-strain ATP C-strain Abstract Tagging MRI is applied to assess the myocardium using grid-like pulses. The quantitative analysis of distortion of the lattice allowed the evaluation of the regional myocardial wall motion. In this study, we assess the ischemic myocardium wall motion quantitatively using circumferential strain value (C-strain value), obtained with tagging MRI in adenosine triphosphate stress. In ATP stress, the intact myocardium showed increased C-strain value, whereas the ischemic myocardium showed decreased that significantly. The C-strain value may detect the ischemic myocardium quantitatively. 06 MRI 1 tagging MRI cine 2 tagging MRItag pulse strain 3 Yasuhiro Shiraishi 1) (52330), Tomoyuki Kido 2), Akihiko Kojima 1) (53751), Haruka Okubo 1), Hiroshi Suekuni 1), Satoshi Yamauchi 1) (56568), Kosuke Ueda 1) (18674), Hiroyuki Tagashira 1) (22485) 1) Department of Radiology, Ehime University Hospital 2) Department of Radiology, Ehime University Graduate School of Medicine tag pulse 3.0T SNR signal-noise ratio B 0 4 cine Steady-state Steady-state B 0 Banding 5 tagging MRI tag pulse 6 adenosine triphosphate ATP perfusion MRI LGE late gadolinium enhanced MRI ATP 2 3 7 8 5 10 23 1303
MRI 9 ATP ST 10 ST MRI 9 ATP 2 1 ATP tagging MRI ATP tagging MRI strain 1-2MRI ATP MRI Figure 1. meglumine gadopentetate perfusion MRI 0.05mmol/kg total:0.1mmol/kg 11 ATP 140 g kg -1 min -1 11 tagging MRI 3 ATP perfusion MRItagging MRI 5 perfusion MRI LGE late gadolinium enhanced MRI 5 11 look-locker 12 inversion time Rest Stress Stress LV Rest Lookscout LGE tagging PWI tagging function PWI Locker 1 1-1 Table 1. ATP MRI CABG 22 11 8 52 12 1061.3 20-82 11 28.2 Characteristic Table 1. Value Number of patients 22 Age (years; mean SD) 61.3 14.1 Male sex 12 (55%) Hypertension 12 (55%) Hyperlipidemia 8 (36%) Diabetes mellitus 5 (23%) Family history 4 (18%) Smoking 9 (41%) BMI 23.5 4.0 LVEF (%) 55.8 11.4 LVEDV (ml) 125.4 43.6 LVESV (ml) 59.0 38.6 1-3 MRIAchieva 3.0T Quasar Dual; Philips Healthcare Best the Netherlands 10min 15min 25min 45min Figure 1. ATPMRI 32-element cardiac phased-array coil 16posterior elements 16 anterior elements Osirix in Tag http:// www. osirix-viewer. com 1-4 C-strain C-strain Circumferential strain tag pulse Figure 2. strain strain = d t -d 0 /d 0 d t t d 0 24 1304 2013. vol.60 no.732
ATP Tagging MRI Arts and Sciences circumferential strain a) Basal b) Mid b) Apical radial strain Figure 3. a b c 1-5 Figure 2. tagging MRI 2D turbo fieldecho sequence with a rest-grid pulse TR = 4.6ms TE = 2.7ms FA = 12 slice thickness = 8mm FOV = 380mm matrix size = 288 195 SENSE factor = 2.5 tag grid = 6.0mm and 20 cardiac phases perfusion MRI 3D-T 1 turbo field echo with k-t BLAST 3D-T 1 TFE with k-t BLASTTR = 3.7ms TE = 1.85ms FA = 20 slice thickness = 8mm FOV = 400mm matrix size = 256 179 k-t BLAST factor = 5. LGE late gadolinium enhanced 3D inversion recovery T 1 turbo field echo 3D IR-T 1 TFETR = 3.5ms TE = 1.69ms inversion time = 400 500ms null point look-locker FA = 15 slice thickness = 6mm FOV = 350mm matrix size = 224 157 SENSE factor = 2.0 1-6 1-6-1 tagging MRI 3 12Figure 3. ATP perfusion MRI >25 LGE perfusion MRI LGE >25 perfusion MRI LGE 1-6-2 C-strain 3 12ATP C-strain C-strain C-strain C-strain 1-6-3 ROC C-strain perfusion MRI LGE MRI ROC receiver operating characteristics 0.05 C-strain C-strain C-strain JMP version 9; SAS Institute Cary NC USA ROC MRI2 2 2-1 ATP perfusion MRI 842 8 6 06 25 1305
Figure 4. The absolute circumferential-strain(c-strain) differences between stressed and at-rest tagged images. Bars and horizontal lines indicate means and standard deviations. *p<0.01, **p<0.001 2 例で梗塞を認めた LGE において心筋梗塞症例は 5 例で そのうち 21 セグメントを検出した 心筋梗塞 を認めた 5 例中 3 例で虚血は認めず 2 例で虚血を認 めた 2-2 各セグメントの C-strain 値 ATP 負荷時および安静時の C-strain 値をセグメン トごとに分類し Table 2. に示した それぞれをグラ フにし Figure 4. に示した Figure 4. 負荷時および安静時の円周方向のひずみ値 Circumferential-strain; C-strain を グ ラ フ化 バーと横線は平均値と標準偏差を表し ている *p<0.01 **p<0.001 Table 2. ATP負荷時および安静時におけるtagging MRIによって得られた円周方向のひずみ Circumferential strain ; C-strain 値を非虚血 虚血 梗塞心筋ごとに分類 Rest C-strain % Segment No. of segments Non-ischemic 201 14.6 10.8 Ischemic 42 16.4 6.2 Infarcted 21 8.6 6.7 p value Stress C-strain % p value 18.6 13.0 n.s. 9.7 13.2 <0.001 <0.01 3.9 11.5 <0.001 p value: the difference with respect to non-ischemic segments 非虚血およびコントロールセグメントにおける C-strain 値は安静時で 15 ± 11% 18 ± 9% ATP 負荷時で 19 ± 13% 23 ± 11% と ATP 負荷時 で有意に高くなった p<0.001 虚血セグメントに おける C-strain 値は安静時で 16 ± 16% ATP 負 荷時で 10 ± 13% と ATP 負荷時で有意に低くな った p<0.01 梗塞セグメントにおける C-strain 値は安静時で 9 ± 7% ATP 負荷時で 4 ± 12% と ATP 負荷時 で低くなったが p=0.17 有意なものではなかった ATP 負荷時および安静時における梗塞セグメント の C-strain 値は 非虚血およびコントロールセグメ 静時の C-strain 値の差 Δ C-strain 値 は 4 ± 15 Figure 5. Changes in the circumferential-strain(δc-strain) among 5 ± 10 と 虚血および梗塞のΔ C-strain 値 ischemic, non-ischemic infarcted, and control segments. -7and ± 12-5 ± 10indicate P<0.001 Bars horizontal lines means よりも有意に高く and standard deviations. なった Figure *p<0.001. 5. ントに比べ有意に低かった 非虚血セグメントにお ける ATP 負荷時の C-strain 値は 虚血セグメントに 比べ有意に高くなったが 安静時では両者に差は認 められなかった さらにコントロールセグメントの C-strain 値は ATP 負荷 安静時において非虚血 虚血 梗塞のいずれのセグメントと比較しても有意に 高かった 梗塞心筋ごとにグラフ化 2-3 各セグメントのΔ C-strain 値の比較 非虚血およびコントロールセグメントの負荷時と安 26 1306 Figure 5. 負荷時から安静時の円周方向のひずみ値を差 し引 い た も の ΔCircumferential-strain;Δ C-strain を コントロール 非虚血 虚血 日本診療放射線技師会誌 2013. vol.60 no.732
ATP Tagging MRI Arts and Sciences 2-4 ROC C-strainMRI 2 perfusion MRI LGE MRI ROC Figure 6. a) b) C-strain C-strain 74 ATP C-strain Figure 8. perfusion MRI C-strain C-strain a) b) rest C-strain stress C-strain c) Figure 7. 28 ATP Circumferential-strain; C-strain C-strain a C-strain b C-strain 06 a) Figure 6. C-strain MRI 2 perfusion MRILGE MRI ROC a C-strainb C-strainc C-strain C-strain C-strain 0.58 AUC 81% 37% 44% ATP C-strain 0.79 AUC 86% 65% 68% C-strain - -0.05% 0.76 AUC 84.1% 63.1% 66.4% 2-5 Figure 7. 28 b) c) 3 rest C-strain septal anterior stress C-strain Figure 8. 74 ATP MRI Circumferential-strain; C-strain C-strain C-strain b C-strain c C-strain ATP tagging MRI C-strain 27 1307
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