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Type:
Educational Exhibit
Keywords:
Abdomen, Anatomy, Small bowel, CT, Education, Diagnostic procedure, Inflammation, Neoplasia
Authors:
T. Simelane1, H. Khosa2, N. Ramesh2; 1Dublin/IE, 2Portlaoise/IE
DOI:
10.1594/ecr2015/C-1385
Background
The mesentery is a double fold of the peritoneum.
True mesenteries {the small bowel,
the transverse mesocolon and the sigmoid} all connect to the posterior peritoneal wall.
Some mesenteries do not connect to the posterior peritoneal wall--
- The greater omentum: connects the stomach to the colon
- The lesser omentum: connects the stomach to the liver
- The mesoappendix: connects the appendix to the ileum
The small bowel mesentery is a broad fan-shaped fold of peritoneum connecting the loops of jejunum and ileum to the posterior abdominal wall Its connection with the posterior abdominal wall,
its root,
measures about 15 cm and extends obliquely from the duodenojejunal flexure on the left of the second lumbar vertebra to the right lower quadrant anterior to the upper part of the right sacroiliac joint.
Mesenteric fat has a same density as the fat in the subcutaneous tissue {- 100 to -160 HU}.
Infiltration of the increases the density to {- 40 to -60 HU } with loss of the sharp interface with the vascular structures – a hazy appearance that is often referred to as a “Misty Mesentery”
This pathological increase in mesenteric fat attenuation is non-specific and may be secondary to infiltration of the mesenteric fat with inflammatory cells,
malignant cells,
fibrosis or fluid { blood,
oedema,
lymph}
It is ususally an incidental finding,
however,
underlying disease may need to be excluded,
idiopathic is often labelled as mesenteric panniculitis