Computed tomography (CT) plays an important role in diagnosis of acute intestinal obstruction and planning of surgical treatment. Although internal hernias are uncommon, they may be included in the differential diagnosis in cases of intestinal obstruction, especially in the absence of a history of abdominal surgery or trauma. CT findings of internal hernias include evidence of small bowel obstruction (SBO); the most common manifestation of internal hernias is strangulating SBO, which occurs after closed-loop obstruction. Therefore, in patients suspected to have internal hernias, early surgical intervention may be indicated to reduce the high morbidity and mortality rates. In a study of 13 cases of internal hernias, nine different types of internal hernias were found and the surgical and radiologic findings were correlated. The following factors may be helpful in preoperative diagnosis of internal hernias with CT: (a) knowledge of the normal anatomy of the peritoneal cavity and the characteristic anatomic location of each type of internal hernia; (b) observation of a saclike mass or cluster of dilated small bowel loops at an abnormal anatomic location in the presence of SBO; and (c) observation of an engorged, stretched, and displaced mesenteric vascular pedicle and of converging vessels at the hernial orifice.

Diffusion-weighted imaging is extremely useful in detecting CJD during the very early phase-even before the onset of characteristic clinical findings.

The frequency of delayed adverse reaction to nonionic monomeric contrast media was 2.1%; the most common reactions were itching and limited urticaria.

Dynamic MRI is useful for distinguishing high-flow from low-flow vascular malformations, especially when the contrast rise time of the lesion is measured.

We investigated 7505 inpatients who underwent intravenous urography or contrast-enhanced computed tomography to assess risk factors for delayed adverse drug reactions to iohexol, a non-ionic iodinated contrast medium. Focusing on delayed adverse reactions, all adverse events were prospectively investigated for 7 days after injection of iohexol. To explore the relevant risk factors, the relationship between occurrence of adverse reactions to iohexol and 17 different variables was evaluated by logistic regression analysis. To assess the influence of seasonal factors, adverse reactions were separately evaluated during two periods: February to April (the pollinosis period in Japan) and July to September (the non-pollinosis period). The prevalence of delayed adverse events and delayed adverse reactions was 3.5 and 2.8%, respectively, whereas the prevalence of adverse events and adverse reactions was 5.7 and 5.0%, respectively. Multivariate analysis showed that six parameters had a significant influence on delayed adverse reactions to iohexol, including (a) a history of allergy, (b) season, (c) radiographic procedure, (d) age, (e) concomitant surgery or other invasive procedures, and (f) concomitant medication. The prevalence of delayed reactions was lower than in previous large-scale studies. Significant risk factors included a history of allergy and per-formance of radiography during the pollinosis period, suggesting that allergy was involved in delayed adverse reactions. The type of radiographic procedure also had an influence.