An 86-year-old woman with several episodes of bright blood per rectum.
86岁女性，发现鲜血便多次。
Noncontrast, arterial-phase, and delayed-phase CT images of the abdomen are shown below. Click to enlarge.
下图所示分别为CT平扫、动脉期、延迟期。
1.Active gastrointestinal (GI) bleeding is demonstrated in which of the following vascular territories?
活动性消化道出血属于下列哪支血管供血区？
Left hepatic artery 肝左动脉
Middle colic artery 中结肠动脉
Left colic artery 左结肠动脉
Right colic artery 右结肠动脉
Additional questions
2.A lower GI bleed is defined as bleeding originating beyond the ligament of Treitz.
下消化道出血是指出血点位于屈氏韧带远侧。
True
False
3.Positive oral contrast is routinely administered prior to CT imaging for suspected lower GI bleed.
临床怀疑下消化道出血，CT检查时常规口服造影剂有助于诊断？
True
False
选择题答案：
Middle colic artery
True
False
Findings and Diagnosis
FindingsPrecontrast images from abdominal CT demonstrate absence of hyperdense material in the transverse colon. Arterial and venous phase images demonstrate pooling of intraluminal contrast in the midtransverse colon in keeping with active lower gastrointestinal bleed, likely branches from the superior mesenteric artery. There is diverticulosis involving the ascending, transverse, and descending colon without evidence of diverticulitis.
Lower GI bleed due to angiodysplasia 血管发育不良所致下消化道出血
Lower GI bleed due to diverticulosis 憩室病所致下消化道出血
Upper GI bleed 上消化道出血
Artifact 伪影
DiagnosisLower GI bleed due to diverticulosis
憩室病致下消化道出血
Discussion
Lower gastrointestinal (GI) bleed represents a bleeding source distal to the ligament of Treitz and accounts for 25% of all GI bleeding. This is most commonly related to diverticulosis, with diverticular hemorrhage more common in the right colon. Other etiologies include angiodysplasia, inflammatory bowel disease, iatrogenic, and neoplasm.
Bright blood per rectum is more suggestive of lower GI bleed versus upper GI bleed, which may present with melena.
鲜血便一般提示下消化道出血出血，而上消化道出血一般为黑便。
Important vascular territories to consider诊断下消化道出血出血时，需要了解以下重要的血管及其供血区。
Superior mesenteric artery (SMA): Middle colic artery divides into a right and left branch with anastomose with right and left colic.肠系膜上动脉（SMA）:发出中结肠动脉分出左右两支，分别与左结肠动脉、右结肠动脉吻合。
Right colic artery divides into ascending and descending branches and supplies ascending colon.右结肠动脉分为升支和降支，供应升结肠。
Ileocolic artery is the terminal branch of the SMA and supplies cecum and distal ileum.回结肠动脉是SMA最远端的分支，供血盲肠和回肠远端。
Inferior mesenteric artery (IMA): Left colic artery supplies descending colon.肠系膜下动脉（IMA）:发出左结肠动脉，供血降结肠。
Ascending branch of left colic artery: Anastomoses with middle colic artery.左结肠动脉升支：与中结肠动脉吻合。
Superior rectal artery: Terminal branch of IMA.直肠上动脉：IMA最末端的分支。
Marginal artery of Drummond is anastomotic arcade formed by the various IMA branches and courses along the mesenteric border of the colon.边缘动脉，即Drummond血管弓，指IMA分支的弓形吻合，沿着结肠系膜的边缘分布。
Internal iliac artery: Middle and inferior rectal arteries supply rectum.髂内动脉：发出直肠中动脉、直肠下动脉供应直肠。
