CT scanning demonstrates enlarged lymphatic nodes and annular thickening of the intestinal wall, especially at the terminal ileum; diffuse enlargement of the spleen with uneven density of some nidi and sheet nidi with low density that reveal splenic abscess or destruction, which can be identified by enhancement scanning; moderate enlargement of the liver compared with enlarged spleen; and even thickening of the cholecystic wall with even low density by enhancement scanning. Some results show ascites and a few reveal intestinal perforation, bleeding, and abscess (Figs. 24.2, 24.3, and 24.4).

Examinations reveal mild hydrocephalus, slightly expanded encephalocele but without sulcus and cistern expansion, localized and diffuse decrease of white matter density, and parts of enhanced nidi. In addition, enhanced meninx line and diffusely enhanced gyri are often seen, while basilar cistern and ependyma are rarely enhanced. CT scanning reveals common features of encephalitis, meningitis, and meningoencephalitis, which may exist together or solely.

Pulmonary infections often involve pulmonary mesenchyme, which is characterized by bronchial vascular bundles and interlobular and intralobular septum thickening. Reticular opacity and reticular nodes with clear edges and slightly high density can be seen in the lungs.

Imaging demonstrations of paratyphoid fever A, B, and some paratyphoid fever C are similar, which are generally characterized by annular thickening of the intestinal wall, especially the terminal ileum. Mesenteric lymphatic nodes, spleen, and liver enlarge. Some of the cases are present with ascites and a few with intestinal perforation, bleeding, and abscess. Septicopyemia caused by paratyphoid fever C can mainly induce suppurative inflammation, which is characterized by systemic suppurative metastatic nidi, of which localized suppurative inflammation in the lungs, bones, and joints, meningitis as well as endocarditis are the most common (Fig. 24.5).