This abdominal CT you may often miss!

The patient, a 61-year-old male, had increased stool frequency in the past 3 months, yellow and soft stool, no blood and black stool, no nausea and vomiting
.
The inflammatory and tumor indexes were negative, and the full abdominal enhanced CT was performed after coming to the hospital, as follows↓

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Poor midgut rotation

Origin of the small intestine

The proximal end of the small intestine, ascending colon, and transverse colon mainly originate from the midgut in the embryonic stage and are supplied by the superior mesenteric artery; The distal transverse colon, descending colon, sigmoid colon, and rectum originate in the hindgut in the embryonic stage and are supplied by the submesenteric artery
.

The length of the small intestine in adults is about 5 meters, so its development rate is significantly faster than that of other organs in the embryonic stage, but the volume of the blastocyst is so large, what to do? Only this pile of midgut tubes first through the umbilical cord "hernia" out of the abdominal cavity, and then wait for the abdominal cavity to vacate the place to "herniate" this part of the intestine back, in this process of entering and exiting, the midgut tube to this oversized midgut undergo 2 physiological rotations, after that, the mesentery and posterior peritoneum fuse, and fix the midgut evolved intestinal tube on the
posterior peritoneum.

Poor rotation

If these two physiological rotations cannot be successfully completed, it is called midgut malrotation, which is a congenital disease, and the imaging manifestations are jejunum, ileum, and large intestine position disorders
.
Severe congenital intestinal malrotation, neonates may present with frequent vomiting, milk spraying, vomit containing bile; Mild midgut malrotation usually has no obvious clinical symptoms, and often presents with less severe dyspepsia, constipation and other atypical symptoms, so it is difficult to detect
.
These patients are often diagnosed by "sharp-eyed" radiologists when they need to go to the hospital for abdominal CT because of other diseases
.

However, patients with poor rotation of the midgut have imperfect mesentery and ligament development, which is more likely to occur intestinal obstruction, volvulus and other diseases than normal people, and will also lead to unexplained stool frequency, indigestion and other symptoms, and it is easy to accept a large number of unnecessary examinations as potential gastrointestinal tumor patients, so it is necessary for radiologists to deepen their understanding of this disease and improve the diagnosis rate
.

Image representation

Imaging diagnosis of poor rotation of the midgut is not difficult, mainly to remember the normal anatomical position of the small intestine, the normal imaging features of the jejunum and the normal walking of the superior mesenteric artery branch.

Keep in mind the normal anatomical location and features of the abdominal cavity tube in the figure above: the jejunum is located in the left upper quadrant, the mucosal folds are abundant, and the ileum
is strengthened above the same level.

In patients with small bowel obstruction, the contrast between the dilated jejunum (red arrow) and the ileum is conducive to understanding the imaging features
of both.

Keep in mind the important walking characteristics of the SMA branch in the figure above: jejunal artery branches are more numerous and go to the lower left (yellow dotted line box), while the ileum, ileosic artery, ascending colon, and proximal transverse colonic artery branches are sparse.

Finally, look at it again to deepen the impression!