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Medical Imaging International
New System Expands Neuro and Cardiac MRI Capabilities new magnetic resonance imaging (MRI) system enables healthcare providers to produce higher resolution images for myriad exams in less than five minutes. The Canon Medical Systems (Otawara, Japan; https://global.medical.canon) Galan 3T XGO offers the ability to conduct quick, comfortable, and high-quality neuro MRI exams, as well as faster sampling and higher-resolution images. The system comes with the allnew Saturn X Gradient, which provides up to 30% improved signal-to-noise ratio (SNR) for brain diffusion weighted imaging (DWI), resulting in even higher resolution neuro images. And by stacking protocol sequences, neuro sequences such as SAG T1, AX T2, AX T2 FLAIR, AX T2 and AX DWI/ADC can be performed in less than five minutes. Galan 3T XGO also delivers enhanced cardiac capabilities, including T1 mapping using a modified looklocker inversion (MOLLI) recovery sequence that allows quantitative characterization of myocardial tissue within a single breath hold. In addition, cardiac phase sensitive inversion recovery (PSIR) provides improved contrast in late-enhanced imaging and eliminates the need for inversion time (TI) calibration scan, allowing cardiac exams to be completed with fewer breath holds and greater patient comfort. New PURERF shielding technology maximizes the radiofrequency
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Oxygen Microbubbles Sensitize Tumors to Radiation Therapy njecting breast cancer with oxygen-filled microbubbles makes tumors three times more sensitive to radiation therapy (RT), according to a new study. Researchers at Thomas Jefferson University (TJU; Philadelphia, PA, USA; www.jefferson.edu), Drexel University (Philadelphia, PA, USA; www.drexel.edu), and other institutions conducted a murine study in order to investigate if surfactant-shelled oxygen microbubbles injected intravenously into a tumor and “popped” by noninvasive ultrasound could elevate hypoxic tumor oxygen levels, thus making them more sensitive to RT. The researchers managed to show that the injected oxygen microbubbles successfully increased breast tumor oxygenation levels by 20 mmHg, significantly more than control injections of saline or untriggered oxygen microbubbles. Using photoacoustic imaging, the researchers also showed that using the microbubbles ensured that oxygen delivery was independent of hemoglobin transport, and thus effective in avascular regions of the tumor. Overcoming hypoxia by this method immediately prior to RT nearly triples RT radiosensitivity, resulting in roughly 30 days of improved tumor control, as well as statistically significant improvements in tumor growth and survival. The study was published on January 21, 2018, in the International Journal of Radiation Oncology* Biology* Physics. “Finding a way to reverse oxygen deficiency in tumors has been a goal in radiation therapy for over 50 years. Oxygen microbubbles flush tumors with the gas, and make radiation therapy significantly more effective in animal models,” said senior author John Eisenbrey, PhD, of Jefferson University. “The very act of bursting these microbubbles within the tumor tissue seems to change the local physiology of the tumor and make cells generally more permeable to oxygen and potentially to chemotherapy as well.” Microbubbles are bubbles smaller than one mm in diameter, but larger than one micrometer. Gas-filled microbubbles oscillate and vibrate when a sonic energy field is applied and may reflect ultrasound waves. But because gas bubbles in liquid lack stability and therefore quickly dissolve, microbubbles must be encapsulated with a solid shell made from a lipid or a protein, such as albumin.
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Medical Imaging International November-December/2018
(RF) transmission efficiency for optimal image quality and an increase of up to 20% in SNR, while MultiBand SPEEDER technology allows for multiple slices to be acquired at the same time, reducing DWI scan times by up to two times. Patients undergoing MR exams can also enjoy the new MR Theater, an immersive virtual experience that gives patients a visual focal point to distract them from the exam, encouraging them to relax and stay still, enabling clinicians to produce efficient, highquality imaging. Image: An immersive virtual experience helps patients relax during an MRI scan (photo courtesy of Canon Medical Systems).