Blood in the belly: CT findings of hemoperitoneum.

Hemoperitoneum may occur in various emergent conditions. In the trauma setting, evidence of intraperitoneal blood depicted at computed tomography (CT) should lead the radiologist to conduct a careful search of images for the injured visceral organ (the liver or spleen). Specific CT signs, such as a sentinel clot or extravasation of intravascular contrast material, may indicate the source of bleeding and help direct management. In addition, the configuration of accumulated blood may help identify the injured organ; for example, triangular fluid collections are observed in the mesentery most often in the setting of bowel or mesenteric injury. Less commonly, hemoperitoneum may have a nontraumatic origin. Iatrogenic hemoperitoneum may occur as a complication of surgery or other interventional procedures in the abdominal cavity or as a result of anticoagulation therapy. Hemoperitoneum also may be seen in the setting of blood dyscrasias such as hemophilia and polycythemia vera. Tumor-associated hemorrhage, which most often occurs in hepatocellular carcinoma, hepatic adenoma, or vascular metastatic disease, also may produce hemoperitoneum. Other potential causes of nontraumatic hemoperitoneum are gynecologic conditions such as hemorrhage or rupture of an ovarian cyst and rupture of the gestational sac in ectopic pregnancy, and hepatic hematoma in syndromic hemolysis with elevated liver enzymes and low platelet count (HELLP syndrome). Vascular lesions (visceral artery aneurysms and pseudoaneurysms) that occur in systemic vascular diseases such as Ehlers-Danlos syndrome or in pancreatitis are another less common source of hemoperitoneum.

CT of pregnancy-related complications.

During pregnancy, the risk of radiation exposure to the fetus is increased so that more than the usual benefit is necessary to justify computed tomography (CT; or other radiation exposure) than in non-pregnant patients. In the setting of a life-threatening illness, CT may be indicated to assess for potentially fatal complications such as hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome. After delivery, patients rarely develop serious problems requiring radiologic evaluation. When indicated, however, CT may be invaluable in making the diagnosis or determining the severity of peri- and post-partum complications, including uterine perforation, hemorrhage, endometritis, thrombophlebitis, and abscess formation. At times, CT may be the first to uncover conditions, such as post-partum cardiomyopathy, and heart failure, which are usually diagnosed by other modalities but may explain the symptoms for which the study was ordered. In some centers, CT pulmonary angiography represents the standard of care to diagnose pulmonary thromboembolism. In this article, we illustrate the spectrum of peri-partum and post-partum complications on CT to familiarize the radiologist with the CT features of these potentially life-threatening pregnancy-related complications.

High rates of recombination in otitis media isolates of non-typeable Haemophilus influenzae.

Non-typeable (NT) or capsule-deficient, Haemophilus influenzae (Hi) is a common commensal of the upper respiratory tract of humans and can be pathogenic resulting in diseases such as otitis media, sinusitis and pneumonia. The lipopolysaccharide (LPS) of NTHi is a major virulence factor that displays substantial intra-strain and inter-strain variation of its oligosaccharide structures. To investigate the genetic basis of LPS variation we sequenced internal regions of each of seven genes required for the biosynthesis of either the inner or the outer core oligosaccharide structures. These sequences were obtained from 25 representative NTHi isolates from episodes of otitis media. We found abundant evidence of recombination among LPS genes of NTHi, a finding in marked contrast to previous analyses of biosynthetic genes for capsular polysaccharide, a well-documented virulence factor of Hi. We found mosaic sequences, linkage equilibrium between loci and a lack of congruence between gene trees. These high rates were not confined to LPS genes since evidence for similar amounts of recombination was also found in eight housekeeping genes in a subset of the same 25 isolates. These findings provide a population based foundation for a better understanding of the role of NTHi LPS as a virulence factor and its potential as a candidate vaccine.