Reduction of scan time in imaging mass spectrometry

• US 20070141718A1
• Filed: 12/19/2005
• Published: 06/21/2007
• Est. Priority Date: 12/19/2005
• Status: Abandoned Application

• Current Assignee: Thermo Finnigan LLC (Thermo Fisher Scientific Incorporated)
• Original Assignee: Thermo Finnigan LLC (Thermo Fisher Scientific Incorporated)
• Inventors: Bui, Huy
• Application Number:
  US11/312,294
• Publication Number:
  US 20070141718A1
• Time in Patent Office: Days
• US Class Current: 436/173
• CPC Class Codes: H01J 49/0004 Imaging particle spectrometry
• CPC Class Codes: Y10T 436/24 Nuclear magnetic resonance, electron spin resonance or other spin effects or mass spectrometry

Abstract

Techniques are disclosed for reducing scan times in mass spectral tissue imaging studies. According to a first technique, a tissue imaging boundary is defined that closely approximates the edges of a tissue sample. According to a second technique, a low-resolution scan is performed to identify one or more areas of interest within the tissue sample, and the identified areas of interest are subsequently scanned at higher resolution.

Claims

1. A method for irradiating tissue samples for mass spectrometric analysis, comprising steps of:

capturing an image of at least a portion of a tissue sample; and

generating a non-rectangular tissue imaging boundary.

2. The method of claim 1, further comprising the steps of:

selecting a set of spaced apart target regions lying within the tissue imaging boundary; and

irradiating the target regions sequentially.

3. The method of claim 1, wherein the step of generating the tissue imaging boundary includes:

displaying the image of the tissue sample;

receiving operator input defining the tissue imaging boundary; and

displaying the tissue imaging boundary superimposed on the image of the tissue sample.

4. The method of claim 3, wherein the operator input is a free-drawn line.

5. The method of claim 3, wherein the operator input includes at least one point at least partially defining a non-rectangular shape.

6. The method of claim 2, wherein the spaced apart target locations are arranged in a rectilinear grid.

7. The method of claim 1, wherein the step of generating a non-rectangular boundary comprises automatically processing the tissue sample image to locate the outer border of the tissue sample.

8. The method of claim 2, wherein the step of irradiating the target locations sequentially comprises directing a laser beam to impinge on a first target region, and repositioning at least one of the laser beam or the tissue sample such that the laser beam impinges on a second target region.

9. A method of operating a mass spectrometer for tissue imaging, comprising steps of:

loading a sample support plate into the mass spectrometer, the sample support plate having a tissue sample placed on a surface thereof;

capturing an image of at least a portion of a tissue sample;

generating a non-rectangular tissue imaging boundary;

storing data representing the tissue imaging boundary;

removing the sample support plate from the mass spectrometer;

preparing the tissue sample; and

re-loading the sample support plate into the mass spectrometer.

10. The method of claim 9, wherein the step of preparing the tissue sample includes applying a layer of matrix to the tissue sample.

11. The method of claim 9, wherein the step of re-loading the sample plate into the mass spectrometer includes reading sample support plate position indicia.

12. The method of claim 9, further comprising the steps of:

selecting a set of spaced apart target regions lying within the tissue imaging boundary; and

irradiating the target regions sequentially following the re-loading step.

13. The method of claim 9, wherein the step of generating the tissue imaging boundary includes:

displaying the image of the tissue sample;

receiving operator input defining the tissue imaging boundary; and

displaying the tissue imaging boundary superimposed on the image of the tissue sample.

14. The method of claim 13, wherein the operator input is a free-drawn line.

15. A mass spectrometer system, comprising:

an imaging device for capturing an image of a tissue sample;

a processing unit, coupled to the imaging device, configured to generate a non-rectangular tissue imaging boundary and select a set of target regions located within the boundary;

a radiation source configured to sequentially irradiate the target locations to produce analyte ions; and

a mass analyzer for measuring the mass-to-charge ratios of the analyte ions or product ions derived therefrom.

16. The mass spectrometer of claim 15, wherein the processing unit is configured to cause the tissue sample image to be displayed, to receive operator input defining the tissue imaging boundary;

and to cause the tissue imaging boundary to be displayed superimposed on the image of the tissue sample.

17. The mass spectrometer of claim 16, wherein the operator input is a free-drawn line.

18. The mass spectrometer of claim 15, wherein the target regions are arranged in a rectilinear grid.

19. A processing unit for a mass spectrometer configured to:

receive an image of an image of a tissue sample;

generate a non-rectangular tissue imaging boundary; and

select a set of target regions lying within the tissue imaging boundary.

20. The processing unit of claim 19, wherein the processing unit is further configured to cause the tissue sample image to be displayed, to receive operator input defining the tissue imaging boundary;

and to cause the tissue imaging boundary to be displayed superimposed on the image of the tissue sample.

21. The processing unit of claim 20, wherein the operator input is a free-drawn line.