内頸動脈の偽閉塞を同定するための多相コンピュータ断層撮影血管造影所見

Multiphasic Computed Tomography Angiography Findings for Identifying Pseudo-Occlusion of the Internal Carotid Artery.

• Jai Ho Choi
• Jinhee Jang
• Jaseong Koo
• Kook-Jin Ahn
• Yong Sam Shin
• Bum-Soo Kim

抄録

背景と目的:

急性虚血性脳卒中患者の治療計画において，内頸動脈（ICA）の擬似閉塞と真の閉塞の鑑別は重要である．我々は，前循環型急性虚血性脳卒中患者における頸部ICA偽閉塞と頸部ICA真性閉塞の多相CTアンギオグラフィの所見を比較し，診断的価値を検討した．

BACKGROUND AND PURPOSE: Differentiation between pseudo-occlusion and true occlusion of internal carotid artery (ICA) is important in treatment planning for acute ischemic stroke patients. We compared the findings of multiphasic computed tomography angiography between cervical ICA pseudo-occlusion and true occlusion at the cervical ICA in patients with anterior circulation acute ischemic stroke to determine their diagnostic value.

方法:

近位ICAが非視認性であった30例を対象とした。ICAの偽閉塞と真閉塞の診断は、デジタルサブトラクションアンギオグラフィを用いて行った。多相CTアンギオグラフィ所見-(1)炎状の切り株と(2)頸部ICAでの遅延造影充填-の診断性能を評価し、比較した。データ解析には、Fisher exact test、χ test、Wilcoxon rank-sum test、McNemar testを用いた。

METHODS: Thirty patients with nonvisualization of the proximal ICA were included. Diagnosis of pseudo- or true occlusion of the ICA was made based on digital subtraction angiography. Diagnostic performances of multiphasic computed tomography angiography findings-(1) a flame-shaped stump and (2) delayed contrast filling at the cervical ICA- were evaluated and compared. The Fisher exact test, χ test, or Wilcoxon rank-sum test and McNemar test were used in the data analysis.

結果:

12例が真の近位ICA閉塞、18例が偽閉塞であった。多相CT（コンピュータ断層撮影）による頸部ICAの造影剤充填の遅延は偽閉塞の全例で認められたが，真性閉塞の1例では造影剤充填の遅延が認められた（<0.001）．炎状切株の存在は疑似閉塞群と真性閉塞群で有意差は認められなかった。遅発性造影充填の感度（0.94 [95% CI, 0.73-1]）は、炎状切株の有無（0.75 [95% CI, 0.36-0.83]）よりも有意に高かった。

RESULTS: Twelve patients had true proximal ICA occlusion and 18 had pseudo-occlusion. Delayed contrast filling at the cervical ICA on multiphasic computed tomography angiography was found in all patients with pseudo-occlusion of the ICA, while 1 case of true occlusion showed delayed contrast filling (<0.001). The presence of a flame-shaped stump was not significantly different between the pseudo- and true occlusion groups. The sensitivity of delayed contrast filling (0.94 [95% CI, 0.73-1]) was significantly higher than that of flame-shaped stump (0.75 [95% CI, 0.36-0.83]).

結論:

我々は，多相CTアンギオグラフィにおける遅延充填標識が，近位ICA偽閉塞と真の閉塞を鑑別するために有用であり，かつ容易に利用可能な所見であることを示した．

CONCLUSIONS: We demonstrated that the delayed filling sign on multiphasic computed tomography angiography could be a useful and readily available finding for differentiating proximal ICA pseudo-occlusion from true occlusion.