Re: cardiac PET scan

"John Wendel" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I heard,if the patient has normal resting blood flow perfusion the
FDG-PET is not indicated.and FDG is not used in te rest/stress
study.The need for FDG-PET study is based on the results of rest/stress
study.If the above is true, is cardiolite(resting) blood flow perfusion
with SPECT camera as accurate as with rubidium resting blood flow
perfusion and PET camera,since resting cardiolite blood flow perfusion
results tells whether or not FDG-PETis indicated?Is inconclusive
cardiolite resting blood flow perfusion study followed with rubidium
resting blood flow perfusion studyThanks

Most places would do Cardiolite first, then follow up with PET if there is a
question on the Cardiolite. This is basically a cost factor. PET is more
expensive than SPECT.

Andrew

What happens if cardiolite resting blood perfusion is false negative
and thus person does not follow up with FDG PET and rubidium? Should
person just skip half PET/half SPECT study and do whole study with
PET(because of better accuracy)?Thanks

"John Wendel" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Does anyone know if cardiac PET or SPECT testing distinguish an area of
old injury(scar tissue) from a newer injury caused by a recent heart
attack?Thanks

If the tissue is dead, both tests will show an area with no perfusion.

PET is better than SPECT at finding tissue that is still viable, and thus
would benifit from revascularization. There are also ways to show this in
conventional SPECT, such as delayed thallium imaging.

Andrew

1) If SPECT (cardiolite) testing can't distinguish an area of old injury
(scar tissue) from a newer injury caused by a recent heart attack what
test can? 2) If a person has normal resting cardiolite blood flow
perfusion would this mean person never had (even small) heart attack in
his life?Thanks

[email hidden] (John Wendel) wrote in message news:<[email hidden]>...

Quoted message said:

1) If SPECT (cardiolite) testing can't distinguish an area of old injury
(scar tissue) from a newer injury caused by a recent heart attack what

Ø test can?
Ø
A PYP, aka (PPi or Tc-99m pyrophosphate scan) and In-111
antimyosin(which I don't think is available anymore) can see very
early injury, out too about 7 days, but it is not a particularly
useful test now since the other test for acute myocardial injury are
so good. The short answer in general is no.

2) If a person has normal resting cardiolite blood flow

Quoted message said:

perfusion would this mean person never had (even small) heart attack in
his life?Thanks

In an absolute sense, no. SPECT is relatively low resolution. A small
scar or subendocardial scar could be blurred out and not be
identified. There may be a slight drop in intensity in that region,
but the normal heterogeneity of the images is too great to be able to
always reliably separate normal from miniscule scar. The numbers
quoted for the sensitivity and specificity vary but assuming 85% for
both, simplistically this would mean that 15% tested with disease
would test as normal, false-negative and 15% of those without disease
would test positive, false-positive.

The tests are very good if used properly, but are not perfect.

1) I am not cardiologist,but I always thought that heart attack causes a
dead tissue,but is the tissue that did not die and became scar tissue
called heart attack? 2) If the normal resting cardiolite blood flow
perfusion can not rule out all old large and small heart attacks what
imaging test can? 3) Does FDG with either resting cardiolite or resting
rubidium rules out all old small heart attacks?Thanks

[email hidden] (John Wendel) wrote in message news:<[email hidden]>...

Quoted message said:

1) I am not cardiologist,but I always thought that heart attack causes a
dead tissue,but is the tissue that did not die and became scar tissue
called heart attack?

Tissue, that does not die, does not become scar tissue but stays as heart muscle.

Quoted message said:

2) If the normal resting cardiolite blood flow
perfusion can not rule out all old large and small heart attacks what
imaging test can?

Positron imaging and echocardiography are more sensitive.

Sometimes, a plain old EKG is more sensitive.

Quoted message said:

3) Does FDG with either resting cardiolite or resting
rubidium rules out all old small heart attacks?Thanks

Rubidium would be more sensitive than cardiolite.

--
Dr. Andrew B. Chung, MD/PhD
Board-Certified Cardiologist
http://www.heartmdphd.com

What's sensivity% and specifity% of resting cardiolite,resting rubidium
and echo in ruling out all small heart attacks? What's the sensivity
with FDG and without?Is sensivity higher when both rest and stress
studies are done?Thanks

Dr.Andrew B. Chung I am new at this forum,but I did not get reply from
you to my three questions dated August 12,2003.Thanks

John Wendel said:

Dr.Andrew B. Chung I am new at this forum,but I did not get reply from
you to my three questions dated August 12,2003.Thanks

You'll have to repost them. Sorry.

--
Dr. Andrew B. Chung, MD/PhD
Board-Certified Cardiologist
http://www.heartmdphd.com/

1.Up to what size in cm is heart attack considered large,moderate and
small?2. What's the smallest (in cm) heart attack that PET scan (with
FDG and rubidium) or SPECT (with cardiolite) can easily detect? 3. Which
test is better in diagnosing CAD: a resting only PET scan with FDG and
rubidium or stress echo?Thanks

[email hidden] (John Wendel) wrote in message news:<[email hidden]>...

Quoted message said:

1.Up to what size in cm is heart attack considered large,moderate and
small?

Less than 1-2 cm would be small while greater than 2 cm would be significant.

2. What's the smallest (in cm) heart attack that PET scan (with

Quoted message said:

FDG and rubidium)

0.3-0.5 cm.

or SPECT (with cardiolite) can easily detect?

greater than 2 cm.

Quoted message said:

3. Which
test is better in diagnosing CAD: a resting only PET scan with FDG and
rubidium or stress echo?Thanks

Stress Echo.

--
Dr. Andrew B. Chung, MD/PhD
Board-Certified Cardiologist
http://www.heartmdphd.com