Satoshi Sugiura

Non-contrast-enhanced MR angiography using 3D ECG-synchronized half-Fourier fast spin echo

A non‐contrast‐enhanced three‐dimensional (3D) magnetic resonance angiography (MRA) technique, which acquires images in a reasonably short scanning time and requires no contrast agent, is developed. An electrocardiographically (ECG) synchronized 3D half‐Fourier fast spin‐echo (FSE) technique with an appropriate ECG delay time for every slice encoding in 3D terms was used to examine the thoracic and iliac regions in 16 healthy volunteers at both 0.5 and 1.5 T. Prior to each 3D fresh blood imaging (FBI) experiment, an ECG preparation (ECG‐prep) scan was acquired, and an appropriate ECG triggering time was selected for 3D FBI acquisition to optimize visualization of the vessel of interest. In the thoracic and abdominal regions, good‐quality 3D MRA images were obtained. Furthermore, the weighted subtraction of two images in different phases provides contrast enhancement between arteries and veins. J. Magn. Reson. Imaging 2000;12:776–783.

Automated shimming of B0 for spectroscopic imaging

Abstract A method for automated shimming of B0 in whole body imaging magnets is demonstrated. The method employs spectroscopic imaging [ T. R. Brown, B. M. Kincaid, and K. Ugurbil, Proc. Natl. Acad. Sci. USA, 79, 3532, 1982 ] of 1H to map the B0 field of the region of interest with the subject in situ. Correction currents for the shims, based on prior measurement of shim fields versus shim currents, are then calculated and applied by computer. The chief application of the method is shimming for multivoxel spectroscopy examinations in vivo wherein it is shown to produce marked improvement of 31P spectra from spectroscopic imaging exams of brain and calf muscle, in normal and diseased subjects.

Metabolic response of glioblastoma to adoptive immunotherapy: detection by phosphorus MR spectroscopy.

In a patient with cerebral glioblastoma, metabolic disturbances were detected within the tumor and in the surrounding brain. Within the volume occupied by the tumor, phosphocreatine (PCr)/adenosine triphosphate was reduced and inorganic phosphate/PCr elevated, indicative of tissue necrosis. Loss of total 31P signal was consistent with reduced metabolite content within the area of tumor defined by CT and magnetic resonance (MR). These studies were accomplished with 31P MR spectroscopy at 2 T, using a volume head coil and the technique of two-dimensional phase-encoding to map regional metabolism across the entire cerebral cortex in voxels of 30 cm3. Using the same method, only minor variations in 31P metabolism were noted in six normal controls. Treatment with locally placed Interleukin-2 activated lymphocytes resulted in changes in both MR and 31P MR spectroscopy in the region of the tumor.