Image Co-Registration

Multiple imaging modalities exist in the clinic today, each offering it's own unique advantages to the physician. To be able to take advantage of each imaging systems strength is often challenging to the clinician due to the lack of registration marks native in the scan process or that reside in the patient. Current trials to combine modalities often result in 'home-brewed' systems that are clunky and don't make it past the research/testing phase. To date software methods exist that offer multi-modality registration automatically or with a minimal amount of user intervention but often these still have to be examined with scrutiny, espicially in critical area such as head, neck and spinal cord regions.


Figure 1.
CT reconstruction overlayed with an FMT system reconstruction
This image shows a nunu mouse after an CT imaging session and a session on LBMI's second generation continuous wave imaging system. The alignment is done as an option to our reconstruction routines running on Matlab.

In the LBMI group's Matlab based registration routines, the user is presented with a side by side comparison of a planar reflectance photograph (FMT) and a maximum intensity projection along a coronal CT scan. Along with certain markers already present in the system the user is asked for a single click to register one point in the CT space to a marker presented in the FMT image. The CT is used to present fine structure details while FMT data is used to display the tumor, as details in Figure 1. by the yellow and blue structures.

Once the two coordinate spaces are aligned the usual Matlab flexibility applies and the image can be presented any way the user wishes.

Figure 2. CT reconstruction of a nunu mouse showing lungs (dark red), skin (pink) and skeletal structures (white)
Figure 3. CT reconstruction of a nunu mouse showing lungs (dark red), skin (pink) and tumor structures (blue)

These two images are of a nunu mouse. Figure 2 presents a CT reconstruction showing only the skin, lungs and skeletal system. This mouse has three implanted tumors in the lungs. One can see on the CT an abnormally shaped lung tissue body which is due to the density change of normal healthy tissue to denser tumor tissue.

Figure 4. Raw CT slice showing tumor volume in upper left quadrant inside the rib cage.
Figure 4. CT reconstruction of a nunu mouse with a singular tumor volume in the lower right lung.

These two images are also of a nunu mouse. Figure 1 shows the raw CT slice showing the tumor volume inside the ribcage (upper left) and Figure 2 presents the reconstructed CT co-registered with the molecular information obtained from our FMT imager.