CT contrast phase

視懷疑什麼病，決定CT要掃哪些phase

懷疑aortic dissection: Noncontrast + early arteriole phase

懷疑H.C.C: Noncontrast + late arteriole + portal vein + delayed phase

懷疑appendicitis: Noncontrast + venous phase

Early arteriole (25s): vascular lesion (ex: aortic aneurysm, dissection)
Late arteriole (35s): Hypervascular solid organ (liver, kidney, spleen, pancreas)

Portal vein(75s): H.C.C iso-/hypodense, portal vein thrombosis
Venous phase(90-120s): other solid organ(ex: appendicitis), IVC structure

Delayed phase(240s): H.C.C hypodense
Excretory phase, ex: CT urography(5 min)