Bench Press

A few weeks ago I wrote a post about the development of the Standoff Patient Triage Tool, an impressive use of lasers in order to make health critical readings of patients from a distance. Well one of the best things about science is that many people can utilize the same tools to come up with unique methods and solutions for any given problem. In this case, researchers have used lasers to develop a technology that could someday revolutionize imaging procedures in medicine.

Photoacoustic imaging of melanoma in vivo.

Photoacoustic tomography is the basis behind a new imaging technology being developed in hopes of providing more flexible and cost effective devices for physicians. The technique takes advantage of ultrasonic emissions produced when a non-ionizing laser pulse is directed towards a tissue. The emissions, resulting from transient thermoelastic expansion of the target tissue due to absorption of the laser energy, are detected and analyzed with various algorithms to construct an image (2D or 3D) of the targeted area. This differs from the reliance on the doppler shift produced by the reflected laser beam in the SPTT.

Images of vasculature like the one seen on the right can be produced by using photoacoustic tomography without the injection of contrast as differences between the molecular composition of the target can be used instead. In the example to the right, the difference between oxygenated and deoxygenated blood is an effective natural contrast. Photoacoustic tomography also presents other benefits over traditional imaging techniques as explained by The Economist:

CT scans also involve potentially harmful ionising radiation. And MRI and CT scans are very expensive, using machines that cost millions of dollars and require dedicated staff to operate them. Photoacoustic tomography, by contrast, could eventually be performed using portable hand-held devices, similar to those used for ultrasound scanning. This would allow doctors to diagnose and monitor patients in clinics, and reduce the need to refer them to consultants.

The adaptability of this nascent technology is also impressive as researchers are already looking at using it to detect specific ailments such as brain lesions and cancer. In the case of cancer, the ability to accurately image vasculature could allow doctors to monitor patients for the development of new blood vessels (angiogenesis) a hallmark of cancer development.

While there are some issues to work out with this new technique, such as the lack of imaging depth (ultrasound signal emitted is reduced the deeper the tissue lies) and ultrasound distortion from varying tissue types within the human body (e.g. bone vs muscle), photoacoustic imaging is a very promising new technology.

(Source)

While reading through VentureBeat.com, I chanced upon an article written by Dean Takahashi which caught my interest. Apparently, a team of IBM researchers have developed a microscope with 100 million times the resolution of a conventional MRI. The secret to this amazing success? Magnetic resonance force microscopy (MRFM). Combining the ideas of magnetic resonance imaging and atomic force microscopy, MRFM is sensitive enough to detect the magnetic spin of a single electron and thus, provides a substantially greater resolving power.

From IBM’s abstract:

We have combined ultrasensitive magnetic resonance force microscopy (MRFM) with 3D image reconstruction to achieve magnetic resonance imaging (MRI) with resolution <10 nm. The image reconstruction converts measured magnetic force data into a 3D map of nuclear spin density, taking advantage of the unique characteristics of the “resonant slice” that is projected outward from a nanoscale magnetic tip. The basic principles are demonstrated by imaging the 1H spin density within individual tobacco mosaic virus particles sitting on a nanometer-thick layer of adsorbed hydrocarbons.

While we have seen other exciting developments in the MR industry as well as the imaging industry, this breakthrough is especially revolutionary because of how much it influences the scientific community. If IBM’s new microscope is as good as advertised, we will be able to produce three dimensional images of viruses, view the structure and interactions of proteins, and study the physical nature of certain chemical reactions, all while evading the disadvantages which plague electron microscopy. The benefits of understanding how things work at a molecular level can lead to better modeling, better drugs, smaller chips, and maybe even better detection mediums for cancer.

Here’s a video describing the technique:

A completed magnetometer.

The age old dilemma of magnetic resonsance imaging: do you sacrifice precision for size, or size for precision?

Generally, behemoth MR machines are required to produce images of great detail. The downside? Price, immobility, and an inability to take the device to the field. The tradeoff of using their smaller, less expensive counterparts, however, is their lackluster resolving power. This could all change with John Kitching’s new developments in MR technology. Kitching, a physicist at the National Institute of Standards and Technology, is working on smaller, less expensive MR machines with resolutions that rival their larger cousins. Taking a new spin on an old idea, Kitching has adapted the procedure of producing atomic magnetometers and taken it to a significantly smaller scale.

The result: highly sensitive magnetic sensors about the size of a grain of rice. Kitching believes that mass production is not too far off in the horizon, and with an army of tiny magnetic sensors, the possibilites are endless. Pocket-sized MRIs, anyone?