Re: HEALTH: Diagnostic imaging details urgently desired

From: Geraint Rees (
Date: Fri Jan 18 2002 - 08:54:44 MST

On 18/1/02 1:43 pm, "Robert J. Bradbury" <> wrote:

> Finally one needs to balance the benefit any diagnostic information
> might provide with technology trends. If exposure to ionizing
> radiation produces a cancer or accelerates aging one has to
> balance that against diagnostic information that might result
> with regard to pre-existing conditions.

I agree.

> Our ability to deal
> with the ill-effects of current tests will be significantly
> increased in the future. So tests which significantly serve
> to promote one surviving to that future time (without having
> to be suspended) are perhaps justifiable even if they would
> be considered undesirable in a perfect world.

I agree. However, whole body CT scanning (or NMR scanning, or ultrasound
scanning) is regretfully not a test that significantly serves the goal of
promoting survival to the future. The problem is not just one of risk
(ionizing radiation) vs benefit (diagnose cancer etc). It's also one of
diagnosis; all tests have false-negative and false-positive rates, and this
has to be born in mind when considering the relevance of the test to the
desired outcome. Essentially that's why the American College of Radiology
and the American Cancer Society don't support full-body CT scans.

I'm all in favour of exploring and utilising new technologies that enhance
survival, but imaging techniques might not be the way to go. They tend to be
increasingly successful in diagnostic and treatment decsisions for
individual diseases (e.g. staging lung cancer with positron emission
tomography), but not so much for screening. Perhaps genetic profiling and/or
gene expression arrays will be a better way to go.

Best wishes,


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