Imaging system and methods of high resolution Cherenkov dose images

Patent metadata

Field	Value
Publication number	US-12196894-B2
Application number	US-202117796488-A
Country	US
Kind code	B2
Filing date	Jan 29, 2021
Priority date	Jan 29, 2020
Publication date	Jan 14, 2025
Grant date	Jan 14, 2025

Abstract

A Cherenkov imaging system includes a high-speed radiation detector configured to provide a first timing signal synchronized with pulses of radiation to control operation of at least one pulse-gated, multiple-pulse-integrating, (PG-MPI) CMOS camera synchronized through the digital time signal to pulses of the radiation beam source, to image Cherenkov radiation; and a digital image-processing system. The high-speed radiation detector is either a solid-state radiation detector or a scintillator with a photodetector. The system images Cherenkov light emitted by tissue by using a timing signal synchronized to pulses of a pulsed radiation beam to control the PG-MPI camera by integrating light received by the PG-MPI camera during multiple pulses of the radiation beam while excluding light received by the camera between pulses of the radiation beam.

First claim

What is claimed is:

1. A Cherenkov imaging system comprising:
a radiation detector configured to provide a first timing signal synchronized with pulses of radiation provided by a pulsed radiation beam source;
the first timing signal is coupled to control operation of at least one camera capable of imaging Cherenkov radiation; and
a digital image-processing system;
where the radiation detector is selected from the group consisting of solid-state radiation detectors and radiation detectors of the type comprising a scintillator and a photodetector;
where the at least one camera capable of imaging Cherenkov radiation comprises a pulse-gated, multiple-pulse-integrating, (PG-MPI) CMOS image sensor synchronized through the first time signal to pulses of the radiation beam source.

2. A Cherenkov imaging system of claim 1 wherein a plurality of pixels of the PG-MPI CMOS image sensor each comprise a photodiode coupled through a precharge gate to a precharge level signal, the photodiode also coupled through a transfer gate to a capacitor associated with a storage node, the storage node also coupled through a reset transistor to a reset voltage signal, the storage node also coupled to a gate of a source follower, the source of the source follower being coupled through a select transistor to a data readout line.

3. The Cherenkov imaging system of claim 1 further comprising a second radiation detector configured to provide a second timing signal, and the camera capable of imaging Cherenkov radiation is controlled to image Cherenkov radiation when both the first and second radiation detectors simultaneously detect radiation.

4. The Cherenkov imaging system of claim 3 wherein the digital image-processing system is configured to use the camera capable of imaging Cherenkov radiation to capture an image of Cherenkov emissions and a background image, and to subtract the background image from the image of Cherenkov emissions to generate a corrected Cherenkov image.

5. The Cherenkov imaging system of claim 4 wherein the digital image-processing system is further configured to apply calibration tables to the corrected Cherenkov image to generate a dose map.

6. The system of claim 1 where the pulses of the radiation source have width on the order of microseconds and repeat with period on the order of milliseconds.

7. An imaging unit comprising:
a trigger input adapted for connection to a beam-on output signal provided by a pulsed radiation beam source, the trigger input receiving a digital timing signal;
apparatus configured to communicate the digital timing signal to trigger operation of at least one camera capable of imaging Cherenkov radiation;
where the camera capable of imaging Cherenkov radiation is a pulse-gated, multiple-pulse-integrating, (PG-MPI) CMOS camera synchronized through the digital time signal to pulses of the radiation beam source.

8. A Cherenkov imaging system of claim 7 wherein each pixel of a plurality of pixels of the PG-MPI CMOS camera comprises a photodiode coupled through a precharge gate to a precharge level signal, the photodiode also coupled through a transfer gate to a capacitor associated with the storage node, the storage node also coupled through a reset transistor to a reset voltage signal, the storage node also coupled to a gate of a source follower, the source of the source follower being coupled through a select transistor to a data readout line.

9. The Cherenkov imaging system of claim 7 wherein the digital image-processing system is configured to use the PG-MPI CMOS camera to capture an image of Cherenkov emissions and a background image, and to subtract the background image from the image of Cherenkov emissions to generate a corrected Cherenkov image.

10. The Cherenkov imaging system of claim 9 wherein the digital image-processing system is further configured to apply calibration tables to the corrected Cherenkov image to generate a dose map.

11. A method of imaging Cherenkov light emitted by a phantom or tissue comprising:
providing a timing signal synchronized to pulses of a pulsed radiation beam;
applying the pulsed radiation beam to the phantom or tissue, the pulsed radiation beam causing the phantom or tissue to emit the Cherenkov light;
imaging the Cherenkov light with a pulse-gated, multiple-pulse-integrating, (PG-MPI) camera; imaging the Cherenkov light being performed by integrating light received by the PG-MPI camera during multiple pulses of the radiation beam and not integrating light received by the PG-MPI camera between pulses of the radiation beam.

12. The method of claim 11 where the timing signal synchronized to pulses of the pulsed radiation beam is provided by a radio-optical triggering unit (RTU) configured to detect scattered radiation from pulses of the radiation beam.

13. The method of claim 11 where the timing signal synchronized to pulses of the pulsed radiation beam is provided by a source of the pulsed radiation beam.

14. The method of claim 11 where the timing signal synchronized to pulses of the pulsed radiation beam is provided by logically “AND”-ing signals from two radio-optical triggering units configured to detect scattered radiation from pulses of the radiation beam.

15. The method of claim 14 wherein the PG-MPI camera is configured to integrate the Cherenkov light over at least 10 pulses of the pulsed radiation beam while forming the Cherenkov light image.

16. The method of claim 15 wherein the PG-MPI camera is used to generate a background image of light received from tissue of the subject when pulses of the radiation beam are not present; and further comprising subtracting the background image from the Cherenkov light image to form a corrected Cherenkov image.

17. The method of claim 16 further comprising using calibration tables to convert corrected Cherenkov light images to dose maps.

18. The method of claim 17 further comprising using the dose maps to verify correct treatment is being applied to a subject.

Assignees

• Dartmouth College
• Doseoptics Llc

Inventors

• Bruza Petr
• Pogue Brian
• Krishnaswamy Venkataramanan

Classifications

• G06T2207/30096

  Tumor; Lesion · CPC title

• G06T2207/20224

  Image subtraction · CPC title

• G06T5/50

  using two or more images, e.g. averaging or subtraction · CPC title

• G01T1/02

  Dosimeters (G01T1/15 takes precedence) · CPC title

• H04N25/76

  Addressed sensors, e.g. MOS or CMOS sensors · CPC title