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Protocol - Chest Computed Tomography (CT)

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Description:

A chest computed tomography (CT) is a non-invasive test that shows the size, shape, and structure of the lungs and other structures in the thorax. The chest CT scanning machine takes many pictures, called slices, of the lungs and the inside of the chest. A computer processes these pictures to be viewed on a monitor or printed on film. The computer can also stack the pictures to create a very detailed, three-dimensional (3D) model of the organs. This three-dimensional digital information can be used to measure the dimensions of the structure, such as the bronchial tree, or the density of the structure, such as the lung parenchyma. It is very important that the CT scanner used in any clinical research study be calibrated regularly against calibration standards that are provided by the manufacturer or in some instances by the study itself.

Specific Instructions:

None

Protocol:

A. Subject Preparationfor CT Scan

1. Prior to the study, the subjects identity will be confirmed according to institutional policy.

2. The subject will remove all metallic devices from the chest area.

3. The subject will be informed of the importance of compliance with the breathing instructions. Ability to comply with instructions should be assessed, and conditions that might impair compliance such as deafness, breathlessness, or mental impairment should be noted.

4. At least one rehearsal of the end-inspiratory breath-hold should be performed.

B. CT Acquisition

All CT scans will be obtained using the protocol and breathing instructions as indicated. Scans must be reconstructed using two algorithms, edge enhancing and smooth. Contiguous end-expiratory CT images will also be obtained where possible.

Instructions for CT Scan Acquisition

GENERAL: This study consists of two scouts (topograms) and two scans. All scans use the same parameter grid.

CONTRAST: Oral/IV. None.

SUPINE INSPIRATION: Start at bottom of lungs, end at top of lungs. Instruct the patient to breathe as follows:

"For the first part of this study you will be asked to hold your breath for about 20 seconds. If you cannot hold your breath that long, try the best you can and then take very shallow, slow breaths if you need to."

"For now, take several easy, deep breaths and relax while we prepare to take a CT scan of your lungs."

Allow patient to breathe and relax for at least 15 seconds.

"I am now going to give you specific breathing instructions. Try to follow as best you can."

"Take in a deep breath....and let it out."

"Take in another deep breath....and let it out."

"Take in another deep breath, and hold your breath in. Keep holding your breath!"

Scan the patient in one breath-hold at full-inspiration.

When the scan is completed, tell the study participant to "Breathe and relax!"

SUPINE EXPIRATION: Same protocol as SUPINE INSPIRATION. Start at bottom of lungs, end at top of lungs. Instruct the patient to breathe as follows:

"For the second part of this study you will be asked to blow out your breath and hold it out for about 20 seconds. This is usually more difficult than holding your breath in, but do the best that you can. If you cannot hold your breath out that long, take a very slow shallow breath in if you need to."

"For now, take several easy, deep breaths and relax while we prepare to take the last CT scan of your lungs."

Allow patient to breathe and relax for at least 15 seconds.

"I am now going to give you more specific breathing instructions. Try to follow as best you can. "

"Take in a deep breath....and let it out."

"Take in another deep breath....and let it out."

"Take in another deep breath, let it out, and hold your breath out! Do not breathe!"

Scan the patient in one breath-hold at expiration as quickly as possible.

When the scan is completed, tell the study participant to "Breathe and relax!"

Inspiratory CT
Inspiratory CT
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Expiratory CT
Expiratory CT
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Protocol Name from Source:

The Expert Review Panel has not reviewed this measure yet.

Availability:

Publicly available

Personnel and Training Required

A trained radiologic technologist

Equipment Needs

The equipment necessary is an MDCT scanner. These are usually in the radiology departments of any major hospital. General Electric® (GE), Philips®, Siemens®, and Toshiba® all make MDCT scanners, which cost around $2 million; the room that the scanner is contained in generally costs around $1 million to build because of the need for lead shielding. Therefore, clinical study scans are usually performed under subcontract to a radiology department at a hospital or clinic or through a study radiologist with access to an MDCT machine. If computerized image segmentation processing and analysis is to be performed, this will require a separate computer workstation, usually a Personal Computer (PC), with the image sets from the MDCT scanner being transferred to the computer workstation by direct computer link or through burning DVDs.

General Electric® is a registered trademark of the General Electric Company.

Philips® is a registered trademark of Koninklijke Philips Electronics N.V.

Siemens® is a registered trademark of Siemens Healthcare.

Toshiba® is a registered trademark of Toshiba Corporation.

Requirements
Requirement CategoryRequired
Major equipment Yes
Major equipment Yes
Specialized training Yes
Specialized training Yes
Specialized requirements for biospecimen collection No
Specialized requirements for biospecimen collection No
Average time of greater than 15 minutes in an unaffected individual No
Average time of greater than 15 minutes in an unaffected individual No
Mode of Administration

Physical Measurement

Life Stage:

Adult, Adult

Participants:

Ages 18 and above

Selection Rationale

The recommended protocol is taken from the COPDGene Study. This is a multi-center National Institutes of Health-funded study that is looking at genome-wide association studies (GWAS) in human subjects with chronic obstructive pulmonary disease (COPD) and is using MDCT scanning to define the phenotype of these subjects. The protocol for undertaking MDCT scanning in clinical trials is changing as the MDCT scanners become more technologically advanced. Effectively, the protocol used should balance the radiation exposure from the MDCT scan against the information that the MDCT scan is expected to provide. In general, the lowest radiation dose to achieve the objectives of the study is what is required. As the radiation dose increases, the image clarity is also better, whereas in low radiation doses, the image may not be as clear (so-called "noise").

Language

English, English

Standards
StandardNameIDSource
Common Data Elements (CDE) Person Chest Computed Tomography Text 2969940 CDE Browser
Logical Observation Identifiers Names and Codes (LOINC) Resp chest CT proto 62617-6 LOINC
Derived Variables

Done

Process and Review

The Expert Review Panel has not reviewed this measure yet.

Source
National Institutes of Health, COPDGene Study, Manual of Procedure, 2008.
General References

None

Protocol ID:

90401

Variables:
Export Variables
Variable NameVariable IDVariable DescriptionVersiondbGaP Mapping
Respiratory
Measure Name:

Chest Computed Tomography (CT)

Release Date:

January 29, 2010

Definition

Chest computed tomography (CT) is a painless, non-invasive test that creates precise images of the structures in the chest, such as the lungs.

Purpose

The purpose of multi-detector computerized tomography (MDCT) scanning for research purposes relating to the thorax is generally to provide anatomical images. This structural assessment is a very accurate depiction of the lungs and their components, including airways, lung parenchyma, and lung vasculature. Additionally, the heart is also imaged when the lung images are acquired. At times, heart images can also be informative in the clinical research subject with lung problems.

Keywords

respiratory, lung, chest, CT scan, chest computed tomography, multi-detector computerized tomography, MDCT, COPDGene Study