The present invention provides a method of detecting microbubbles in a vessel of an affected part, comprising aggregates the microbubbles, acquiring phase-contrast magnetic resonance images and analyzing the phase-contrast magnetic resonance images. Thus, we can detect or monitor the size and location of MBs in vessels of any part of body.本發明提供一種偵測一待測部位之管狀物內微氣泡的方法,包含:施予一超音波於該待測部位以聚集該複數個微氣泡,以及取得並分析一相位對比磁振影像。經由本發明之技術而能夠偵測在身體任何部位之血管中微氣泡的大小與位置。