Can an expert testify as to the details of a medical malpractice case if they are otherwise inadmissible?

" 'While an expert may state on direct examination the matters on which he relied in forming his opinion, he may not testify as to the details of such matters if they are otherwise inadmissible. [Citations.] The rule rests on the rationale that while an expert may give reasons on direct examination for his opinions, including the matters he considered in forming them, he may not under the guise of reasons bring before the jury incompetent hearsay evidence. [Citation.]' " (People v. Coleman (1985) 38 Cal.3d 69, 92, 211 Cal.Rptr. 102, 695 P.2d 189.)