2009-02-27 Nobuyuki Kudomi

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MMRO2 using [¹⁵O]O₂-PET

Model

Please check the references below.

Manual for MBF and MMRO2 analyses with [¹⁵O]H₂O and [¹⁵O]O₂ PET study

The procedure works with and without [¹⁵O]CO scan.

1. Setup

Setup your computer as specified here and use the MSYS environment to execute the following commands.

2. Computation of VB if you have [¹⁵O]CO scan

The procedure computes blood volume and provide β value which will be used for input computation.

2-1 Please skip this section and go to section 4, if no [¹⁵O]CO scan

2-2 Draw ROI on LV

        colv.sh <image(ECAT7 format)> <Blood count value>

Firstly, image viewer appears, then draw LV ROI(s) on that image.

1. The image can be enlarged by ‘s’, change the value of ‘zoom’ and cntl-v
2. Also, you can change the scale by inputting the value and change mode as: ‘input by user’
3. ROI could be drawn as: cntl-r, polygon, follow LV region (left click) and close polygon (midle click).
4. Then push ‘ROI calc’ button.
5. Repeat this as far as possible.
6. Finally, close the viewer, File - Quit

After that, program will show the beta value. Beta=0.718009

3. Computation of MBF (With [¹⁵O]CO scan)

The procedure computes MBF and partial tissue fraction (α) values both of which will be used for MMRO2 computation.

3-1 Please go to 4th section if no [¹⁵O]CO scan

3-2 The same ROI on LV from [¹⁵O]CO is used in this procedure

        mbf_with_co.sh <Water image (ECAT7 format)> <beta value>

Firstly, image viewer appears, then draw Myo ROI(s) on that image.

1. The image can be enlarged by ‘s’, change the value of ‘zoom’ and cntl-v
2. Also, you can change the scale by inputting the value and change mode as: ‘input by user’
3. ROI could be drawn as: cntl-r, polygon, follow LV region (left click) and close polygon (midle click).
4. Then push ‘ROI calc’ button.
5. Repeat this as far as possible.
6. Finally, close the viewer, File - Quit

Program will show the K1, Alpha and MBF values in ROI on myocardial tissue.

4. Computation of MBF (Without [¹⁵O]CO scan)

The procedure computes MBF and partial tissue fraction (α) values both of which will be used for MMRO2 computation.

4-1 Please go to 3rd section if you utilize data of [¹⁵O]CO scan

4-2 The procedure draw ROI on LV and myocardial regions and estimate MBF values

        mbf_without_co.sh <Water image(ECAT7 format)>

Firstly, image viewer will appear, then draw LV ROI(s) on that image. Then, image viewer will appear again, then, draw Myo ROI(s) on that image

1. The image can be enlarged by ‘s’, change the value of ‘zoom’ and cntl-v
2. Also, you can change the scale by inputting the value and change mode as: ‘input by user’. When change the setting, ‘cntl-v’ will clean and re-draw the images.
3. ROI could be drawn as: cntl-r, polygon, follow LV region (left click) and close polygon (midle click). Once if you touch a slice, then you cannot go to another slice, so, please be careful about this.
4. Then push ‘ROI calc’ button.
5. Repeat this as far as possible.
6. If zooming is large, part of slices are shown, in this case nest set of slices can be shown by ‘v’.
7. Finally, close the viewer, File - Quit

Program will show the K1, Alpha and MBF values in ROI on myocardial tissue.

5. Generate inverse image of transmission and draw lung ROI

The procedure computes inverse image of transmission image and create lung-TAC, both od which will be used in computing MMRO2 for spillover effect of [¹⁵O]O₂ gas from lung.

4-1 The procedure draw ROI on Lung

        Tr_inverse.sh <Transmission image(ECAT7 format)>

Firstly, image viewer will appear, then draw lung ROI(s) on that image.

1. The image can be enlarged by ‘s’, change the value of ‘zoom’ and cntl-v
2. Also, you can change the scale by inputting the value and change mode as: ‘input by user’. When change the setting, ‘cntl-v’ will clean and re-draw the images.
3. ROI could be drawn as: cntl-r, polygon (or find edge will help you more), follow LV region (left click) and close polygon (midle click). Once if you touch a slice, then you cannot go to another slice, so, please be careful about this.
4. Then push ‘ROI calc’ button.
5. Repeat this as far as possible.
6. If zooming is large, part of slices are shown, in this case nest set of slices can be shown by ‘v’.
7. Finally, close the viewer, File - Quit

Program will generate inverse image.

6. Other parameters,

6-1 If you don’t have blood count data of [¹⁵O]O₂ scan

If you don’t have blood count data of [¹⁵O]O₂ scan,
        o2_blood.sh <O2 image> <Beta>
will estimate it. Beta value can be obtained from either section 2 or 4.

6-2 To obtain Va value from [¹⁵O]CO data

To obtain Va value from [¹⁵O]CO data (If you have estimated beta from [¹⁵O]CO data),
        co_myo.sh

7. Computation of MMRO2 and OEF

The procedure computes MMRO2 and OEF value.

7-1 input following command:

        mmro2_steady.sh <Image (ECAT7 Format)> <Frame from> <to> <Blood volume in Myo> <Blood count> <O2cnt> <MBF> <Alpha>

1. <Image (ECAT7 Format)>: [¹⁵O]O₂ steady state image
2. <Frame from>: First frame to be summed.
3. <to>: last frame to be summed
4. <Blood volume in Myo>: This is from either [¹⁵O]CO data (section 6) or water data (section 4 ‘Va’)
5. <Blood count>: This is from either blood measured data or [¹⁵O]O₂ data (section 6)
6. <O2cnt>: oxygen content = 1.36×<Hb>×<SaO2>
7. <MBF> and <Alpha>: both from section 3 or 4.

8. The process should be done in a same folder for same set of study, but should be different folder for different set of study.

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References:

Agostini D, Iida H, Takahashi A, Tamura Y, Henry Amar M, Ono Y. Regional myocardial metabolic rate of oxygen measured by O₂-15 inhalation and positron emission tomography in patients with cardiomyopathy. Clin Nucl Med. 2001; 26(1): 41-49.

Iida H, Rhodes CG, Araujo LI, Yamamoto Y, de Silva R, Maseri A, Jones T. Noninvasive quantification of regional myocardial metabolic rate for oxygen by use of ¹⁵O₂ inhalation and positron emission tomography. Theory, error analysis, and application in humans. Circulation 1996; 94(4): 792-807.

Katoh C, Ruotsalainen U, Laine H, Alenius S, Iida H, Nuutila P, Knuuti J. Iterative reconstruction based on median root prior in quantification of myocardial blood flow and oxygen metabolism. J Nucl Med. 1999; 40(5): 862-867.

Laine H, Katoh C, Luotolahti M, Yki-Järvinen H, Kantola I, Jula A, Takala TO, Ruotsalainen U, Iida H, Haaparanta M, Nuutila P, Knuuti J. Myocardial oxygen consumption is unchanged but efficiency is reduced in patients with essential hypertension and left ventricular hypertrophy. Circulation 1999; 100(24): 2425-2430.

Yamamoto Y, de Silva R, Rhodes CG, Iida H, Lammertsma AA, Jones T, Maseri A. Noninvasive quantification of regional myocardial metabolic rate of oxygen by ¹⁵O₂ inhalation and positron emission tomography. Experimental validation. Circulation 1996; 94(4): 808-816.

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