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Purpose This study suggests a noninvasive and repetitive measurement method using 1 H magnetic resonance spectroscopy to monitor changes in cellular metabolites within a single sample. Methods Longitudinal acquisition of cellular metabolites from three-dimensional cultured human osteosarcoma (MG-63) cells was conducted using 3.0 Tesla 1 H MRS for 2 weeks at three time points: days 1, 7, and 14. During the MR spectroscopy (MRS) scan, cell specimen temperatures were kept constant at 37°C by a lab-developed magnetic resonance compatible thermostatic device. A DNA assay and live/dead staining of the cell specimens were carried out at each time point to verify the MRS measurements. Results Cell viability in the proposed device did not significantly differ from that of cells in a conventional incubator (P = 0.946). Cell proliferation and choline concentration increased during the first week, but remained constant during the second week. Lactate did not change during the first week, but increased during the second week. Likewise, cell viability remained constant until day 7, then decreased. Conclusion The proposed MRS technique results in a survivable environment for longitudinal studies of cells and provides a new way to measure metabolomic changes over time in single specimens of cells. Magn Reson Med 76:1912-1918, 2016. © 2016 International Society for Magnetic Resonance in Medicine.

Aims The aim of the present study was to investigate whether the effects of vitamin B12 and homocysteine on brain volume are influenced by apolipoprotein E (APOE) genotype. We examined the effects in each subgroup (APOE e4 carriers and non-carriers) of Alzheimer's disease (AD) patients and healthy normal controls. Methods Forty participants with AD and 20 healthy normal controls were recruited from memory impairment clinics at Pusan National University Hospital in Korea. All participants were APOE genotyped and underwent magnetic resonance imaging, including 3-D volumetric images for grey matter (GM) volume. A multiple regression model integrated into statistical parametric mapping was used to see if there was any correlation between vitamin B12 or homocysteine and GM volume in each subgroup (APOE e4 carriers and non-carriers) of AD patients and healthy normal controls. Results There was a significant positive correlation between serum concentrations of vitamin B12 and regional GM volume in APOE e4 carriers with AD but not in non-carriers. We also found that there was a significant negative correlation between serum concentrations of homocysteine and regional GM volume in APOE e4 non-carriers with AD but not in carriers (P < 0.001, uncorrected for multiple comparisons; extent threshold = 100 voxel). Conclusion The present findings suggest that the effects of vitamin B12 and homocysteine on GM volume might be influenced by APOE genotype.

Aims An association between white matter hyperintensities (WMH) and cognitive dysfunction has long been recognized. However, subjects with identically appearing WMH on magnetic resonance imaging present with a wide variance in cognitive function ranging from normal cognition to dementia. The aim of this study was to compare cortical atrophy and integrity of white matter of patients with subcortical vascular dementia of Binswanger type (SVaD-BT) with those of the normal cognition group with WMH (ncWMH). Methods Eleven patients with SVaD-BT and 11 age-, sex-, education- and grade of WMH-matched ncWMH underwent magnetic resonance imaging, including 3-D volumetric images for cortical atrophy and diffusion tensor imaging for integrity of white matter. Results Compared to ncWMH, SVaD-BT patients showed cortical atrophies in frontal (i.e. frontal pole, precentral gyrus and frontal medial cortex) and occipital areas (i.e. lingual gyrus) followed by atrophies in temporal (i.e. fusiform cortex and middle temporal gyrus) areas. Along with cortical atrophies, reduced integrity with low fractional anisotropy and high mean diffusivity values in genu and splenium of the corpus callosum were detected in SVaD-BT patients. Conclusions Our findings suggest that cognitive decline from ncWMH to SVaD-BT may be associated with cortical atrophy and reduced integrity of white matter.

Purpose: To evaluate the temporal and spatial resolution of magnetic resonance (MR) temperature imaging when using the proton resonance frequency (PRF) method combined with the keyhole technique. Materials and Methods: Tissue-mimicking phantom and swine muscle tissue were microwave-heated by a coaxial slot antenna. For the sake of MR hardware safety, MR images were sequentially acquired after heating the subjects using a spoiled gradient (SPGR) pulse sequence. Reference raw (k-space) data were collected before heating the subjects. Keyhole temperature images were reconstructed from full k-space data synthesized by combining the peripheral phase-encoding part of the reference raw data and the center phase-encoding keyhole part of the time sequential raw data. Each keyhole image was analyzed with thermal error, and the signal-to-noise ratio (SNR) was compared with the self-reference (nonkeyhole) images according to the number of keyhole phase-encoding (keyhole-data size) portions. Results: In applied keyhole temperature images, smaller keyhole-data sizes led to more temperature error increases, but the SNR did not decreased comparably. Additionally, keyhole images with a keyhole-data size of

To assess the clinical utility of the breath-hold turbo spin-echo T2-weighted MRI in patients with acute myocardial infarction, the results of MRI were compared with those of electrocardiography, coronary angiography, and thallium-201 single photon emission tomography (SPECT) in 23 patients and 5 healthy volunteers. To compare MRI and thallium-SPECT, the left ventricle was divided into five segments, and the presence of myocardial infarction was determined in each segment. MRI demonstrated an abnormally bright signal in 49 of 140 segments (five segments each from 23 patients and 5 volunteers); thallium-SPECT showed a fixed perfusion defect in 52 segments, for an 85% diagnostic concordance rate. The size of the myocardial infarction measured on MRI corresponded well to that measured on thallium-SPECT (r = .70, P < .01). Breath-hold turbo spin-echo T2 MRI can be used for detection of acute myocardial infarction in conjunction with thallium-SPECT, especially when accurate localization of lesion, increased spatial resolution, and anatomic landmarks are needed.

On the basis of the principles of the time-of-flight method and the 3-D angiogram obtained by the 2-D planar image scanning technique using 90° RF pulses with short repetition time, we have obtained a coronary angiogram around the heart including the coronary arteries and veins. The cine NMR imaging technique is also incorporated in synchronizing ECG R waves to reduce the motion artifact and at the same time to induce the saturation effect on the static samples. Images of the large bulk blood flow corresponding to the heart chamber and descending aorta are further removed by postprocessing. The final 3-D angiogram is then formed by stacking the 2-D images and contrast is further enhanced by the maximum ray tracing algorithm. © 1991 Academic Press, Inc.

A simple and new flow velocity measurement technique using conventional spin-echo sequence is proposed and its applications to a preclinical result are presented. This technique utilizes the phase velocity encoding effect due to 180 degrees rf and its corresponding selection gradient. This phase encoding and its phase velocity relations have been obtained by numerical solution of the Bloch equation. A flow velocity measurement obtained with a volunteer using this proposed technique indicates close agreement with other previously measured values.

An NMR imaging technique applicable to high-velocity flow imaging is described. By subtraction of two phase images obtained by varying the flow-encoding gradient, it is possible to extract much larger ranges of velocity components. This differential phase-encoding technique is tested by experiments in a phantom as well as a human volunteer. © 1987 Academic Press, Inc.