The complementary role of computerized axial transmission tomography and radionuclide imaging of the brain

Leucocyte scanning--a valuable tool in diagnosing cerebral abscess--a survey

Intracerebral abscess is a diagnosis which occasionally can be difficult to establish by using CT scan only. This survey describes the usefulness of a supplementary indium-111 autologous granulocyte scan which may increase the diagnostic specificity in the differential diagnosis between neoplasm and intracranial abscess. Judging from the literature and our own investigations the application of the granulocyte scan is discussed with special reference to the possible pitfalls which can give both false negative and false positive results.

Clinical indications for optimal use of the radionuclide brain scan

427 radionuclide brain scans, performed in 1981 at Guy's Hospital Nuclear Medicine Department, were reviewed retrospectively to define clinical circumstances in which the study provided useful information. It was concluded that the radionuclide brain scan was the appropriate first line investigation in patients with known non-cerebral malignancy, in whom the possibility of cerebral metastases exists; and in patients with a low to moderate probability of subdural haematoma. The radionuclide brain scan can provide a valuable alternative to computed tomography studies:--(1) in patients without known underlying disease who develop localising signs; (2) in patients with focal fits; (3) in patients with underlying vascular disease and gradual onset of localising signs; and (4) in patients with suspected inflammatory conditions of the central nervous system. Outside these groups, the radionuclide brain scan rarely provided useful information.

Radionuclide brain imaging--its role and relation to CT scanning

Separate CNS disease entities are discussed with either the complementary or exclusive indications for radionuclide brain imaging and computerized cranial tomography. Either modality alone has a potential overall precision somewhat in excess of 90% in the localization of cerebral lesions with the effectiveness of each modality differing according to the histology and anatomic location of the lesion. Most investigators agree that the combined application of the two procedures is far superior to their separate use. Routine dynamic isotope studies are essential and in addition, new radiopharmaceuticals and technological advances may improve the radionuclide evaluation of CNS disease. Areas discussed include: primary and secondary CNS neoplasms; acute cerebrovascular accidents; arteriovenous malformations; traumatic cerebrovascular disease; hydrocephalus and dementia; and intracranial inflammatory processes.

Evaluation of x-ray CT (EMI scan) and isotope brain studies, including radioisotope axial tomography

A comparison is made of the results of computer-assisted X-ray tomography (EMI scan) and those of radionuclide brain scan supplemented by computer-assisted isotope tomography. The X-ray examination shows a wider range of positive diagnosis, but the radionuclide examination is complementary in the detection of supratentorial gliomas. A similar comparative value of the isotope tomogram is noted in the detection of cerebral infarcts.