Photo of the Week

December 19, 2006

We have embarked on a new collaborative research project with Prof Charlie Marcus and his group at the Harvard Physics Department. We are developing novel molecular imaging probes for MRI based on hyperpolarized silicon nanoparticles. 29Si in its pure state can exhibit extremely long NMR T1 times, or polarization lifetimes, providing potential for the particles to be hyperpolarized and retain their polarization while reaching a targeted site in a subject. This project is only in preliminary stages at this point, and above, Jacob Aptekar and Jonathan Marmurek, a MIT HST student, are shown in the process of measuring basic Si nanoparticle NMR properties using our 4.7 T NMR spectrometer. The sample had previously been polarized via thermal mixing at high field and low temperature in a superconducting cryostat from the Marcus Group laboratories in the Physics Department that has recently been relocated to the CFA lab to be adjacent to the NMR system. Related details here.
 

December 5, 2006

We have embarked on a new collaborative research project with Prof Charlie Marcus and his group at the Harvard Physics Department. We are developing novel molecular imaging probes for MRI based on hyperpolarized silicon nanoparticles. 29Si in its pure state can exhibit extremely long NMR T1 times, or polarization lifetimes, providing potential for the particles to be hyperpolarized and retain their polarization while reaching a targeted site in a subject. This project is only in preliminary stages at this point, and above, Jacob Aptekar and Rob Barton, a student of Prof. Marcus, are shown in the process of transferring a Si nanoparticle sample from a transport vessel filled with liquid nitrogen, to our 4.7 T NMR spectrometer. The sample had previously been polarized via thermal mixing at high field and low temperature in a superconducting cryostat in the Marcus Group laboratories in the Physics Department. Related details here.
 

November 20, 2006

        

We have acquired the first map of oxygen distribution in the human lung in a subject in the vertical orientation. The image was acquired with the open-access human-research very-low-field MRI system now in use in the Walsworth Group laboratory at the Center for Astrophysics. The subject inhaled a bag of hyperpolarized helium, and their lungs were imaged repeatedly over a breath-hold. The decay rate of the 3He MRI signal can be related to partial pressure of oxygen in each pixel in the image. The resulting pO2 map shows the partial pressure of oxygen, in torr, accroding to the colorbar at right. This image shows a significant gradient in pO2 from head to toe, a phenomenon first postulated in the 1960's but unable to be measured using current clinical imaging methodologies which restrict subjects to lying horizontally. If you'd like to be a subject, contact Ross
 

September 25, 2006

Optics lab equipment and personnel. Visible on the large optical table are three sets of Rb vapor cell experiments (each with its own magnetic shields) for studies of slow and stored light, diffusion-induced Ramsey narrowing, and preliminary Ives-Stilwell tests. Associated lasers and optics are also visible. The N-resonance clock is on a smaller optical table in the background. Related details here.
 

August 28, 2006

        

The second generation, open-access human-research very-low-field MRI system for human lung imaging with hyperpolarized helium is now in use in the Walsworth Group laboratory at the Center for Astrophysics. Human subjects approval was granted by Brigham and Women's Hospital IRB and human trials are under way. If you'd like to be a subject, contact Ross! The photograph above shows a volunteer subject sitting in the magnet in a vertical orientation. The central image shows a 2D projection (no slice selection) image of hypeprolarized helium in the subject's lungs while they are in the sitting position. Fake color is used to enhance the contrast. At right is a 3D volume-rendered image of the subject's lungs while lying horizontally. The lead student on this project for the last three years has just graduated, so if you'd like to work on this exciting project, contact Ron
 

July 26, 2006

After three enjoyable and amazingly productive years, our senior postdoc and CFA fellowship holder, Irina Novikova, is moving on. She will take up a faculty position of College of William and Mary in Williamsburg, Virginia, setting up a new quantum optics research laboratory. On one of her last days at the CFA, Irina and the rest of the current optics group researchers held a last research planning meeting. Irina is shown above with the remainder of the group, from left: Saee Paliwal, Michael Hohensee, Cleo Leung, David Phillips, Yanhong Xiao, Irina, and Mason Klein. We all wish Irina and her family the best for the future adventures. Details of the work Irina contributed to are here and here.
 

May 5, 2006

 

The second generation, open-access human-research very-low-field MRI system is ready for full operation in the Walsworth Group laboratory at the Center for Astrophysics. The magnet and associated hardware has been under construction for 18 months now, and RF B1 coils to accomodate the human chest have been built. Ron is shown above trialling the human chest coil to determine the amount that the coil frequency is changed with a human body inside. This is one of the last steps before human imaging can begin. If you'd like to be a subject, contact Ross! The open-access magnet will eventually be used for imaging the lungs of human subjects in a variety of orientations and postures, as the magnet design allows for two-dimensional rotation of subjects between the magnet coils. 
 

March 21, 2006

Mason Klein is shown preparing for some delicate adjustments to the optical hardware in the Walsworth Group's main optics/stored light laboratory. He is preparing the optical set-up for use in new rubidium-based stored light measurements. Related details here
 

February 8, 2006

The second generation, human-research very-low-field MRI system is nearing completion in the Walsworth Group laboratory at the Center for Astrophysics. The magnet and associated hardware has been under construction for 18 months now, and in the past two weeks, we have assembled a subject support table that integrates the human chest B1 coil. The B1 was built on the form of a cylndircal cardboard sonotube, of the type used for concrete pours on building columns, which we acquired last November. Our success in acquiring 1H MR images of water phantoms is leading us to attempt 1H MRI of body tissue with human subjects, as a precursor for 3He lung MRI. Human experiments will begin as soon as all the relevant safety inspections have been made. If you'd like to be a subject, contact Ross! The open-access magnet will eventually be used for imaging the lungs of human subjects in a variety of orientations and postures, as the magnet design allows for two-dimensional rotation of subjects between the magnet coils.