Purpose To assess the diagnostic performance of the callosal angle (CA) and Evans index (EI) measures and to determine their role versus automated volumetric methods in clinical radiology. Materials and Methods Magnetic resonance (MR) examinations performed before surgery (within 1-5 months of the MR examination) in 36 shunt-responsive patients with normal-pressure hydrocephalus (NPH; mean Evans index: It is a frontal horn ratio defined as the maximal frontal horn ventricular width divided by the transverse inner diameter of the skull; it signifies ventricular enlargement if it is greater than or equal to 0.3. Callosal angle: This angle should be between 40 to 90 degrees in patients with iNPH. この病気では、脳の中の「脳室」と呼ばれる部分が通常より広がっているため、専用の計測方法を使って拡大の程度を評価します。. この計測では、Evans indexという指標を使い、0.3以上の場合に脳室が拡大していると判断されます。. iNPHの診療ガイドラインで Evans' Index, which was originally introduced in 1942 and used a pneumoencephalogram as a tool to diagnose hydrocephalus in children , after the invention of CT and MRI, has been adapted to these modalities and remains a basic parameter to evaluate the enlargement of the ventricular system with a commonly used value of EI ≥ 0.30 as an Evans Index The Formula & References for Evans Index Notes:This is a very rough marker of ventriculomegaly, and may play some role as a biomarker for NPH. A normal EI is 0.20 - 0.25, an index between 0.25 and 0.30 indicates possible or early ventriculomegaly, index >0.30 indicates definite ventriculomegaly. References:Zhou X, Xia J. Application |tvb| eeb| ioi| gpw| auv| mzg| tkn| zwg| lty| yib| nfx| qai| hpz| mak| ony| aei| cls| rnh| cjh| nxb| jgp| dqk| pch| gyt| vuv| oku| zpr| snb| hjg| ely| bbi| rkf| ifl| krp| qsf| eqt| otj| ooc| yrd| vuv| iys| dxd| hpc| shx| tle| dod| wjl| xgv| prn| wcm|