[Computed tomography in the diagnosis of complications in the early postoperative period in patients with tumors of the posterior cranial fossa].

The authors analyse the results of clinico-CT studies in complicated course of the early postoperative period in 104 patients (87 adults and 17 children) with tumors of the posterior cranial fossa (PCF). According to the histological structure and predominant topography of the neoplasm, the cases were divided into 46 extracerebral parastem tumors (meningiomas, neurinomas, chordomas, cholesteatomas) among which 24 extended supratentorially and 22 to Blumenbach's clivus; 23 gliomas of the cerebellum and fourth ventricle; 16 primary gliomas of the stem; 19 other new growths (hemangioblastomas, hamartomas, choroid papillomas, germinomas). A common factor was coexistence of the main complicating condition--circulatory disorder in the stem with edema and dislocation of the stem, disturbed spatial relations between the PCF structures. Dynamic CT studies allowed the authors to differentiate 3 main variants of pathological changes differing in the character of cerebral circulatory disorders: 1st--a wide zone of reduced density in the brain stem; the extent of this zone in the orocaudal direction and its relation to the diameter of the stem (dorsal, ventral, lateral parts) varied; 2nd--combination of zones of reduced density in the stem and cerebellum with hemorrhagic inclusions--multiple "punctate" inclusions or in the form of blood clots; 3rd--in mosaic pattern of the ischemic foci in the stem and cerebellum there was a prevalence of hemorrhages in the form of multiple small extravasations of blood at different levels of the stem, in the subcortical parts, blood clots in the seat of the tumor, hemotamponade of the brain ventricles.(ABSTRACT TRUNCATED AT 250 WORDS)