Ignite Creation Date:
2024-05-05 @ 11:34 AM
Last Modification Date:
2024-10-26 @ 9:10 AM
Study NCT ID:
NCT00088361
Status:
COMPLETED
Last Update Posted:
2008-03-04
First Post:
2004-07-23
Brief Title:
Effect of Respiratory Motion on Positron Emission Tomography Imaging
Sponsor:
National Institutes of Health Clinical Center CC
Organization:
National Institutes of Health Clinical Center CC
Study Overview
Official Title:
The Effects of Respiratory Motion on CT Based Attenuation Correction of Positron Emission Tomography Data Liver and Heart Studies
Status:
COMPLETED
Status Verified Date:
2006-06
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
This study will determine how breathing motions may affect positron emission tomography PET scans It has been discovered that the quality of PET scans varies according to which part of the breathing cycle patients hold their breath
NIH Clinical Center patients 12 years of age and older who are scheduled to have PET and computed tomography CT scans as part of their standard medical care may be eligible for this study
Participants have their scheduled PET or CT scan as they normally would and are asked to hold their breath after breathing out as is usual In addition for this study patients are also asked hold their breath after breathing in and again at a point between breathing in and out Each breath-hold is for around 15 seconds The scans for each of the three different breath-holds are examined for differences
Some patients may also be asked to breathe through a tube called a pneumotachometer or spirometer to determine their normal breathing pattern This involves breathing through a mouthpiece similar to a snorkel mouthpiece and takes about 2 minutes
NIH Clinical Center patients 12 years of age and older who are scheduled to have PET and computed tomography CT scans as part of their standard medical care may be eligible for this study
Participants have their scheduled PET or CT scan as they normally would and are asked to hold their breath after breathing out as is usual In addition for this study patients are also asked hold their breath after breathing in and again at a point between breathing in and out Each breath-hold is for around 15 seconds The scans for each of the three different breath-holds are examined for differences
Some patients may also be asked to breathe through a tube called a pneumotachometer or spirometer to determine their normal breathing pattern This involves breathing through a mouthpiece similar to a snorkel mouthpiece and takes about 2 minutes
Detailed Description:
Current clinical FDG imaging with the NIHs PETCT machine and in fact with most commercial PETCT machines requires a CT scan be acquired prior to the PET scan This CT scan is used for attenuation correction of the PET data and to permit fusion of anatomical and metabolic image data
One difficulty with use of the CT scan for attenuation correction CTAC is that the CT scan is rapid compared to the breathing cycle Each CT slice captures the lungs at one usually arbitrary phase of the respiratory cycle The PET data on the other hand take many minutes to acquire and so average the motion effects of the entire respiratory cycle together This freezing of the respiratory cycle by the CT and blurring of the respiratory cycle during PET produces a mis-match between the PET and CT data This mis-match can produce improper attenuation correction during PET reconstruction especially at soft tissuelung interfaces The existence of this phenomenon has been reported in the literature 1-7 especially at the dome of the liver but it has not been thoroughly quantified Little or no data is available to indicate the quantitative errors the effect produces in cardiac imaging8 This despite the fact that the myocardium is only about 10mm thick and it has been reported that the heart moves on average 9mm and as much as 14mm during a single average respiratory cycle9
The purpose of this protocol is to determine the degree to which respiratory motion may influence quantitative PET imaging especially at the lungliver interface and free wall of myocardium By characterizing the magnitude of the effect we hope to gain knowledge about when correction for the effect is and is not necessary It is hoped that the information gained will also allow us to suggest potential methods to perform such corrections
To gain the above information we will modify the CT acquisition protocol for subjects already scheduled to undergo a whole body FDG PETCT scan In summary rather than acquiring the usual single full radiation exposure CT taking approx 20-30 seconds we will acquire 3 CT scans each taking approximately 20-30 seconds each at 13 the usual radiation exposure Each CT will be acquired at a different phase of the respiratory cycle as opposed to current acquisition which is only at end-expiration The subsequent PET data will be acquired as usual but will be processed and analyzed separately with each of the CT scans and also with a summed CT scan
Note that subjects agreeing to participate in this protocol will receive no additional radiation exposure Participation in the protocol will extend the current overall scan time typically greater than 45 minutes a very small amount about 40-60 additional seconds for imaging and about 60 additional seconds for patient set up etc
One difficulty with use of the CT scan for attenuation correction CTAC is that the CT scan is rapid compared to the breathing cycle Each CT slice captures the lungs at one usually arbitrary phase of the respiratory cycle The PET data on the other hand take many minutes to acquire and so average the motion effects of the entire respiratory cycle together This freezing of the respiratory cycle by the CT and blurring of the respiratory cycle during PET produces a mis-match between the PET and CT data This mis-match can produce improper attenuation correction during PET reconstruction especially at soft tissuelung interfaces The existence of this phenomenon has been reported in the literature 1-7 especially at the dome of the liver but it has not been thoroughly quantified Little or no data is available to indicate the quantitative errors the effect produces in cardiac imaging8 This despite the fact that the myocardium is only about 10mm thick and it has been reported that the heart moves on average 9mm and as much as 14mm during a single average respiratory cycle9
The purpose of this protocol is to determine the degree to which respiratory motion may influence quantitative PET imaging especially at the lungliver interface and free wall of myocardium By characterizing the magnitude of the effect we hope to gain knowledge about when correction for the effect is and is not necessary It is hoped that the information gained will also allow us to suggest potential methods to perform such corrections
To gain the above information we will modify the CT acquisition protocol for subjects already scheduled to undergo a whole body FDG PETCT scan In summary rather than acquiring the usual single full radiation exposure CT taking approx 20-30 seconds we will acquire 3 CT scans each taking approximately 20-30 seconds each at 13 the usual radiation exposure Each CT will be acquired at a different phase of the respiratory cycle as opposed to current acquisition which is only at end-expiration The subsequent PET data will be acquired as usual but will be processed and analyzed separately with each of the CT scans and also with a summed CT scan
Note that subjects agreeing to participate in this protocol will receive no additional radiation exposure Participation in the protocol will extend the current overall scan time typically greater than 45 minutes a very small amount about 40-60 additional seconds for imaging and about 60 additional seconds for patient set up etc
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| 04-CC-0237 | None | None | None |