A.顱腦腫瘤的檢查首選普通X線,次選CT B.腦出血的檢查首選CT,次選MRI C.腰椎間盤突出的檢查首選CT,次選MRI D.椎管內(nèi)腫瘤的檢查首選MRI,次選CT E.肝臟腫瘤的檢查首選超聲,次選CT
A.物質(zhì)厚度的絕對(duì)值 B.物質(zhì)密度的絕對(duì)值 C.物質(zhì)衰減系數(shù)與水相比的相對(duì)值 D.物質(zhì)厚度的相對(duì)值 E.物質(zhì)衰減系數(shù)的絕對(duì)值
A.≤0.001mm B.≤0.01mm C.≤0.1mm D.≤1mm E.≤10mm