Tuesday, January 20, 2009

Brain imaging using brain power

Brain imaging studies, especially those based on behavioral or social aspects, always get a lot of publicity. Most top journals including Nature, Science, PNAS, etc. often highlight works in this research area. It is quite easy to get side-tracked by some of these works. This is partly because so little is known that any interpretation can easily sell without enough proof. There, however, are researchers who strictly follow evidence-based medicine. The studies these researchers conduct take a lot longer to finish and it means less papers. However, in the long run, the latter have a lasting impact on the field. This post highlights a paper by researchers from MIT and UCSD (Vul et al., Perspectives on Psychological Science, 2009, in press), where they have critically examined metrics that are used to describe brain imaging studies in social neuroscience experiments. This work is extremely interesting and presents a lot of food for thought.

Monday, January 12, 2009

Rebinning of time-of-flight Positron Emission Tomography data to no-time-of-flight

Positron Emission Tomography scanners that are capable of measuring time-of-flight (TOF) have undergone several iterations over the past 30 years. However, while there is little doubt that, theoretically, these scanners should yield improved spatial resolution, the amount of data measured are overwhelming. Thus, taking full advantage of the additional timing parameter has becomes difficult. This post highlights work done to address this issue at Dr Richard M. Leahy's laboratory at USC (Cho et al., Phys Med Biol. Feb 2009), where the Fourier re-binning technique has been used for dimensionality reduction of the TOF data to convert it to non-TOF data. This work has been short-listed in Institute of Physics' selected papers. Very promising work, to say the least.

Thursday, January 8, 2009

pH activated fluorescent probes

Fluorescent probes activated by the environment they are in show tremendous promise for molecular imaging because of their improved specificity, and in turn, reduced autofluorescence from the background. This post highlights a paper from a Japanese group (Urano et al., Nature Medicine, Dec 2008) that shows imaging results of a fluorescent agent that, "is activated after cellular internalization by sensing the pH change in the lysosome." These probes potentially should be useful in optical fluorescence tomography, where small lesions can be missed because of autofluorescence effects.

Tuesday, January 6, 2009

Combined optical imaging and mammography

Multimodality imaging has become the buzzword this decade as many medical systems that combine two or more imaging modalities have become commercially available. My first post is about a paper from Dr David Boas's research group at MGH (Fang et al, IEEE Trans Med Imaging, Jan 2009). This paper shows preliminary data and reconstructed images obtained from healthy subjects using a system that combines diffuse optical breast imaging with X-ray mammography. The analysis of pressure from breast compression as it affects blood re-distribution is extremely interesting. Highly recommended by me!