下消化道出血术前影像：DSA

理想的技术（Optimal Technique）

诊断和下消化道出血的栓塞需要高质量的血管造影图像显示清晰的解剖轮廓，做到

Proper rate to fill vessel without inflow 合适的注射速率充盈血管

充足的容量能够发现造影剂外溢（通常4-5秒）Adequate volume to be able to identify extravasation (usually 4-5 seconds)

肠系膜上造影

Using Air in Colon（air infufflation ）

Failure to Cover Full Extent of Artery

出血点险些出覆盖范围（最下方）	右结肠动脉出自腹腔动脉

投照没有足够低的中心 Failing to Center Low Enough

Value of Selective Injection



Non selective injection from SMA trunk	Selective injection in ileocolic branch

Value of Selective Injection


造影剂外溢？	Yes！

治疗干预的机会

OPPORTUNITY FOR THERAPEUTIC INTERVENTION

造影剂外溢发现 0.5 mL/min

敏感性 40-86%，激发试验血管造影（妥拉苏林15-30mg）改善敏感性，

SENSIVITY 40-86%, CAN BE FURTHER SENSITIVE WITH PROVOCATIVE ANGIOGRAPHY (VASODILATOR TOLAZOLINE 15-30 mg)

痉挛有助于避免伪影
SPASMOLYTICS CAN BE HELPFUL TO AVOID IMAGE ARTEFACTS

SELECTIVE ANGIOGRAPHY OF SMA, IMA AND IIA WITH 4-5F CATHETER

20mL AT 5mL/s FOR SMA; 12mL AT 3mL/s FOR IMA

DIRECT SIGNS - EXTRAVAZATION OF CONTRAST MEDIA

INDIRECT SIGNS 一 PSA, ARTERIAL WALL IRREGULARITIES

OR VASCULAR TANGLE WITH EARLY VEIN DRAINAGE