本研究為利用MRI 飛躍時間技術掃描TOF (Time of Fly)與利用MIP (Maximum Intensity Projection)技術做出不同切面的威利氏環(Circle of Willis)週遭血管之立體相關位置，不過因為掃描的範圍的限制下可能導致讓診斷出錯誤的結果。一位45 歲男性，疑似有基底動脈中風(vertebral basilar ischemia)，利用一組威利氏環血管的3D-TOFMRA之MIP 影像以及一組使用對比劑(Contrast Median)的頸總動脈CCA (Common Carotid Artery)血管磁振造影，再掃描一組T2 加權(T2 weight)影像。結果掃描出來後3D-TOF MRA 之MIP 顯示出左邊VA 有嚴重狹窄(stenosis)，注射顯影劑後的CCA 影像，因為掃描範圍較廣，可以明顯的指出是右邊VA 接近基底動脈那段才是嚴重狹窄近乎阻塞。因此要觀察腦內血管影像就必須把3D-TOF MRA 之MIP 影像與原始影像(row data)、CCA 影像一起加入診斷參考，這樣就可以大幅降低誤判的結果。

This study used MRI technology, TOF (Time of Fly) and MIP (Maximum Intensity Projection) to show thedifferent aspects of the 3D (three-dimensional) position-related of blood vessels around the Willie’s Cycle. But because ofthe scanning range limitation, it may lead to incorrect diagnosis results. A 45-year-old male, suspected of basilar arterystroke (vertebral basilar ischemia), he accepted the exam, MIP image from 3D-TOF MRA (Magnetic ResonanceAngiography) of Willie’s Cycle, MIP image from 3D contrast-enhanced MRA of CCA (Common Carotid Artery) and T2(T2 weight) image, The MIP image from 3D-TOF MRA of Willie’s Cycle shows severe stenosis on the left side VA(vertebral Artery), the MIP image from 3D contrast-enhanced MRA of CCA was because of the broader scanning range, itobviously indicated that the right side VA near the basilar was serious narrow and almost total occlusion. Therefore, thesurvey of the brain vascular must consider the MIP image from 3D-TOF MRA of Willie’s Cycle, row data image and MIPimage from 3D contrast-enhanced MRA of CCA, and that you can significantly reduce misdiagnosis.