一位患有 COPD 的72歲男性正坐在標準的金屬輪椅上，被推往放射科進行緊急的 MRI (磁振造影) 掃描。他正從一個未經固定的直立式 D 型氧氣鋼瓶接受氧氣補充。當護理師將病患推向 MRI 掃描室大門（第 IV 區）時，必須立即攔截哪一項災難性的安全風險？
A 72-year-old male with COPD is being transported via a standard metal wheelchair to the radiology suite for a stat MRI scan. He is receiving supplemental oxygen from a free-standing, unsecured D-tank oxygen cylinder. As the nurse pushes the client toward the door of the MRI suite (Zone IV), what catastrophic safety risk must be immediately intercepted?
- AThe static electricity generated by the MRI machine will ignite the high-flow oxygen, causing an explosion.MRI 機器產生的靜電會點燃高流量氧氣，引起爆炸。
- BThe ferromagnetic cylinder and wheelchair will be subjected to the "missile effect," being violently pulled into the machine's magnetic field at high speed.✓ 正解鐵磁性圓柱體和輪椅將遭受「飛射物效應」，被高速強力吸入機器的磁場中。
- CThe unsecured oxygen cylinder can violently tip over, breaking the valve and launching the tank across the hallway.未固定的氧氣鋼瓶可能會猛烈傾倒，閥門斷裂並將鋼瓶發射到走廊另一端。
- DThe electromagnetic field will disrupt the patient's respiratory drive and neutralize the supplemental oxygen saturation.電磁場會干擾病人的呼吸驅動力並中和補充氧氣的飽和度。
本題測試極重要的醫學影像安全：磁振造影（MRI）防護。MRI 掃描儀的心臟是一塊日夜無休、永不關閉的超級磁鐵。當任何含鐵金屬（Ferromagnetic materials，例如標準鋼製輪椅、非鋁合金的氧氣鋼瓶、剪刀、甚至點滴架）一靠近掃描室（Zone 4 區域），就會被無形的龐大磁力瞬間吸入掃描機中心，這個致命的物理現象被廣泛稱為「飛彈效應 (Missile effect)」。由於病患與物體就在途中，這個重達幾十公斤的鋼瓶會像飛彈一樣高速砸碎阻礙它的軀體，導致人員當場死亡。選項C確實是鋼瓶傾倒折斷閥門的潛在風險，但與靠近 MRI 特定環境無關；選項A MRI 本身並未產生導致氧氣燃燒的靜電（那是火災爆炸源）；選項D電磁場不會中和血氧也沒有直接停止呼吸中樞的效力。
This item tests a critically important imaging safety topic: MRI safety. At the heart of the MRI scanner is a super-magnet that never turns off, operating day and night. As soon as any ferromagnetic material (such as a standard steel wheelchair, a non-aluminum oxygen cylinder, scissors, or even an IV pole) approaches the scanner suite (Zone 4), it can be drawn instantly into the center of the scanner by the immense invisible magnetic force, a deadly physical phenomenon widely known as the 'missile effect.' Because the client and other objects are along its path, a cylinder weighing tens of kilograms would fly like a missile and strike anyone in the way, potentially causing immediate death. Option C is indeed a risk if the valve snaps off an unsecured cylinder, but it is unrelated to the specific MRI environment; option A is incorrect because the MRI itself does not generate static electricity that ignites oxygen (oxygen combustion requires an ignition source); option D is incorrect because electromagnetic fields do not neutralize blood oxygen or directly halt the respiratory drive.
飛彈效應 (Missile Effect) 是全球防護 MRI 的金科玉律。在台美醫院，放射科門口均有極其嚴格的管制安檢，即使緊急插管病患推進去前也必須換成全鋁合金氧氣瓶（Non-magnetic cylinder）及塑膠輪椅。