[Quantitative measurement of ventricular dilatation on CT scan--a proposal of new index and review of literature].

CT scan is able to show cerebral atrophy more safely and more easily than pneumo-encephalography or cerebral angiography. Then, various methods have been reported for quantitative analysis of cerebral atrophy on CT scan. Generally, cerebral atrophy might be judged from the ventricular dilatation with some indices, calculated from various ventricular width. But, there is no general agreement on what index is the most reliable. In this paper, we attempted to establish the index, easy to measure and most reliable. Our method is as follow. Method. We carried out the CT scan (EMI 1010) on 89 neurologically intact patients. Scans were parallel to orbito-meatal line (OML), and were 10 mm in thickness. On CT scan films, various width, area of anterior horns and area of bodies of lateral ventricles were measured (Fig. 1). Measurement about the anterior horns of lateral ventricles were carried out on image the most clearly showed the foramen of Monro. And measurements about the bodies of lateral ventricles were on image, 20 mm above the image of anterior horn. Correlations of various width and areas were calculated (Table 1). Then we proposed new indices with high correlations (over 0.9) with ventricular area; Anterior horn CVI (Cerebro-Ventricular Index) and Body CVI (Fig. 2, 3). Patients with myotonic dystrophy show cerebral atrophy. We carried out the CT scan (GE-CT/T 8800) on 17 myotonic dystrophy patients and 30 controls. Between the two groups, age and sex were almost matched (Fig. 4).(ABSTRACT TRUNCATED AT 250 WORDS)