Field-of-view-dependent coincidence window for positron emission tomography
View Patent ↗A method and apparatus for determining a coincidence window for imaging a region of interest of an object using a Positron Emission Tomography (PET) scanner. The method includes determining a diameter of a transverse field of view (FOV) for imaging the region of interest of the object; and calculating the coincidence window based on the determined diameter, a ring diameter of the PET scanner, an axial length of the PET scanner, and a time-of-flight resolution of the PET scanner.
1. A method of determining a coincidence window for imaging a region of interest of an object using a Positron Emission Tomography (PET) scanner, the method comprising:
determining a diameter of a transverse field of view (FOV) for imaging the region of interest of the object; and
calculating the coincidence window based on the determined diameter, a ring diameter of the PET scanner, an axial length of the PET scanner, and a time-of-flight resolution of the PET scanner.
2. The method of claim 1 , wherein the determining step comprises;
determining the diameter of the transverse FOV from a computed tomography (CT) scanogram of the region of interest of the object.
3. The method of claim 1 , wherein the calculating step comprises:
calculating the coincidence window (τ) using the following equation:
τ
=
d
(
mm
)
300
(
mm
/
ns
)
1
+
(
L
D
)
2
+
n
·
FWHM
Δ
TOF
2.355
wherein D is the ring diameter of the PET scanner, L is the axial length of the PET scanner, d is the diameter of the transverse FOV, FWHM ΔTOF is the time-of-flight resolution of the PET scanner, and n is a predetermined number.
4. The method of claim 3 , wherein 2≦n≦3.
5. The method of claim 1 , further comprising:
performing, using the PET scanner, a PET scan of the region of interest of the object using the calculated coincidence window.
6. A method of determining a PET coincidence window for imaging a region of interest of an object using a combined Positron Emission Tomography (PET)-Computed Tomography (CT) scanner, the method comprising:
setting a CT field of view (FOV) based on a size of the region of interest of the object;
setting a diameter of a transverse FOV for PET imaging to be equal to the set CT field of view; and
calculating the PET coincidence window based on the determined diameter, a ring diameter of the PET scanner, an axial length of the PET scanner, and a time-of-flight resolution of the PET scanner.
7. The method of claim 6 , wherein the calculating step comprises:
calculating the coincidence window (τ) using the following equation:
τ
=
d
(
mm
)
300
(
mm
/
ns
)
1
+
(
L
D
)
2
+
n
·
FWHM
Δ
TOF
2.355
wherein D is the ring diameter of the PET scanner, L is the axial length of the PET scanner, d is the diameter of the transverse FOV, FWHM ΔTOF is the time-of-flight resolution of the PET scanner, and n is a predetermined number.
8. The method of claim 7 , wherein 2≦n≦3.
9. The method of claim 6 , further comprising:
performing a PET scan of the region of interest of the object using the calculated coincidence window.
10. A combined Positron Emission Tomography (PET)-Computed Tomography (CT) scanning apparatus, the apparatus comprising:
a CT scanner configured to perform a CT scan of a region of interest of an object using a CT field of view (FOV), which is set based on a size of the region of interest of the object;
a PET scanner configured to perform a PET scan of the region of interest of the object using a PET FOV having a diameter in a transverse plane,
wherein the diameter is determined from the CT scan of the region of interest; and
the PET scanner includes a controller configured to calculate a coincidence window based on the determined diameter, a ring diameter of the PET scanner, an axial length of the PET scanner, and a time-of-flight resolution of the PET scanner.
11. The method of claim 10 , wherein the controller is configured to calculate the coincidence window (τ) using the following equation:
τ
=
d
(
mm
)
300
(
mm
/
ns
)
1
+
(
L
D
)
2
+
n
·
FWHM
Δ
TOF
2.355
wherein D is the ring diameter of the PET scanner, L is the axial length of the PET scanner, d is the diameter of the transverse FOV, FWHM ΔTOF is the time-of-flight resolution of the PET scanner, and n is a predetermined number.
12. A combined Positron Emission Tomography (PET)-Computed Tomography (CT) scanning apparatus, the apparatus comprising:
a CT scanner configured to perform a CT scan of a region of interest of an object using a CT field of view (FOV), which is set based on a size of the region of interest of the object;
a PET scanner configured to perform a PET scan of the region of interest of the object using a PET FOV having a diameter in a transverse plane,
wherein the PET scanner includes a controller configured to set the diameter of the PET FOV in the transverse plane to be equal to the set CT FOV, and to calculate a coincidence window based on the set diameter, a ring diameter of the PET scanner, an axial length of the PET scanner, and a time-of-flight resolution of the PET scanner.
13. The apparatus of claim 12 , wherein the controller is configured to calculate the coincidence window (τ) using the following equation:
τ
=
d
(
mm
)
300
(
mm
/
ns
)
1
+
(
L
D
)
2
+
n
·
FWHM
Δ
TOF
2.355
wherein D is the ring diameter of the PET scanner, L is the axial length of the PET scanner, d is the diameter of the transverse FOV, FWHM ΔTOF is the time-of-flight resolution of the PET scanner, and n is a predetermined number.