Left lower abdominal quadrant contains sigmoid colon,
sigmoid mesentery,
left ureter, lower pole of left kidney,
left ovary and its vasculature at women,
ilopsoas muscle in addition to the retroperitoneal and intraperitoneal spaces and iliac artery and vein.
Despite left lower quadrant pain is not very common; it can be caused by any pathologies of these anatomical structures.
Appendigitis eppiploica,
sigmoid divetriculitis,
ureterolitiasis,
ovarian cyst rupture and abscess of iliacus muscle are some of the pathologies that may resuly in LLQP.
Appendigitis eppiploica (AE) is inflammation of fingerlike fatty tissue from the serosal surface of the colon due to torsion or ischemia.
This is an uncommon condition and presents with acute abdomen and can mimic other acute abdomen etiologies as acute appendicitis,
diverticulitis or cholecystitis according to its location.
Accurate diagnosis is crucial because these patients can be treated without surgery.
Computed tomography findings of AE are:
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Anti-mesenteric ovoid fatty mass with a hyperattenuated ring sign,
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Fat straining at the adjacent fat,
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Thickening of the bowel wall,
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In a minority of cases,
a central high-attenuating dot or line,
corresponding to a thrombosed draining appendageal vein(1,2).
Sigmoid diverticulitis is the most common gastro intestinal reason of LLQP seen at elderly patients.
CT scanning demonstrates
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localized thickening of that part of the sigmoid colon,
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target shaped images of diverticula,
and
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infiltration of the fatty tissue surrounding the colon.
This situation can be complicated with
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abscess of the sigmoid colon or at distant sites,
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fistulae,
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mesenteric vein thrombophlebitis,
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perforation,
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gas in the portal system or the mesentery and finally
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obstructions(3).
By using CT both diagnosis and evaluation of complications of diverticular disease can be made confidently.
Also decision making for percutaneous drainage can be made by CT. The complications of diverticulitis of the sigmoid colon can result in conservative treatment to fail(3).
Ureteroilthiasis. Left ureter traveling through the LLQP can be the cause of the pain.
Secondary CT findings of ureterolithiasis are
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obstruction,
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including hydronephrosis and hydroureter,
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ipsilateral renal enlargement,
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perinephric and periureteric fat stranding,
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perinephric fluid,
and
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ureterovesical edema(4).
Ovarian pathologies. Hemorrhagic ovarian cyst is the most frequent gynecologic condition presenting with lower abdominopelvic pain. Hemorrhagic ovarian cyst and ruptured ovarian cyst may simulate appendicitis when it is on the right side.
On helical CT,
a hemorrhagic ovarian cyst appears as a well-circumscribed structure with attenuation greater than that of simple fluid .
Rupture of the ovarian cyst results in free pelvic fluid and/or fat stranding(5).
Despite the fact that ultrasound is the primary imaging modality of choice for the evaluation of pelvic pathologies in the women,
the usage of CT in the evaluation of abdominal and pelvic pain
continues to expand especially in order to exclude other pathologies of differential diagnosis(6).
Abscess of the iliopsoas muscle is not very common.
It might be idiopathic or secondary,
due to haematogenous spread or contiguous spread from adjacent organs.
CT scanning demonstrates
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enlarged muscle,
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a hypodense fluid collection with thick walls
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indistinct borders,
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sometimes multiple loculations,
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infiltration of adjacent fatty tissue(7).
The treatment is percutaneous drainage and a course of suitable antibiotics (3)