Traditional hospital autopsy rates for patients who die of natural causes have fallen from a high of about 50 percent in the 1960s to about 10 percent today, researchers said Monday.

Johns Hopkins medical experts said in a statement on Monday that one of the reasons behind the drop in conventional autopsy rates is “medical overconfidence” in modern body imaging results, also called “virtopsy” and is also to blame for a high number of diagnostic errors.

Modern virtual imaging technologies which include full-body computed tomography scans, magnetic resonance imaging, ultrasound, X-ray and angiography are helpful in autopsies, but cannot replace the “gold standard” of direct physical inspection of bodily organs, according to autopsy and body imaging experts.

"The traditional autopsy, though less and less frequently performed, is still the gold standard for determining why and how people really died," says pathologist Elizabeth Burton, deputy director of the autopsy service at Johns Hopkins in a statement.

However, modern imaging technologies are valuable when used in combination with autopsies according to researchers but common diagnoses are routinely missed when imaging results are compared to autopsy findings.

"If we chose the right test at the right time in the right people, and followed clinical guidelines to the letter, then modern diagnostic tests would produce optimal results. But we don't," said Burton.

Approximately 23 percent of new diagnoses are detected by autopsies that are missed by modern imaging results, according to Burton.

Burton noted that physicians often choose to skip autopsies to avoid the uncomfortable talk of asking grieving relatives for permission to perform an autopsy that could cost around $3,000 with the prospect of delayed funeral arrangements as well as possible disfigurement to a loved one’s body.

Burton also said many physicians are uninformed on how to get an autopsy performed which includes paperwork and approvals.

German researchers from a previous study that tested the effectiveness of virtopsy, autopsy and the combination of both found that virtual autopsy by CT scan failed to pick up 20.8 percent of new diagnoses while conventional autopsy missed about 13.4 percent.

"Steady progress in imaging technology is refining conventional autopsy, making it better and more accurate," said Mahmud Mossa-Basha, a clinical fellow in neuroradiology at Johns Hopkins and co-author of the review in a statement.

Researchers said that the most common diagnoses missed by imaging techniques were heart attack, pulmonary emboli and cancer.

"Physicians really need to be selective and proactive -- even before a critically injured patient in hospital dies -- in deciding whether an autopsy is likely to be needed and, if so, whether to approach the family in advance. Only in this way do we ensure that we are using the latest scanning devices appropriately during autopsy and when it is most effective in producing the most accurate-as-possible death certificates," said Mossa-Basha.

The Johns Hopkins review is published online in the Annals of Internal Medicine on Tuesday.