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Background: Sensitive detection and quantification of cerebral glucose is desired. Purpose: To quantify cerebral glucose by detecting the H1‐α‐glucose peak at 5.23 ppm in 1H magnetic resonance spectroscopy at 7 T. Study Type: Prospective. Subjects: Twenty‐eight non‐fasted healthy subjects (aged 20–28 years). Field Strength/Sequence: Short echo time stimulated echo acquisition mode (short‐TE STEAM) and semi‐localized by adiabatic selective refocusing (semi‐LASER) at 7 T. Assessment: Single voxel spectra were obtained from the posterior cingulate cortex (27‐mL) using a 32‐channel head coil. The H1‐α‐glucose peak in the spectrum with retrospective removal of the residual water peak was fitted using LCModel with a glucose basis set of only the H1‐α‐glucose peak. Conventional spectral analysis was performed with a glucose basis set of a full spectral pattern of glucose, also. Fitting precision was evaluated with Cramér‐Rao lower bounds (CRLBs). The repeatability of glucose quantification via the semi‐LASER sequence was tested. Statistical Tests: Paired or Welch's t‐test were used for normally distributed values. A P value of <0.05 was considered significant. The repeatability of measures was analyzed using coefficient of variation (CV). Results: Removal of the residual water peak improved the flatness and stability of baselines around the H1‐α‐glucose peak and reduced CRLBs for fitting the H1‐α‐glucose peak. The semi‐LASER sequence was superior to the short‐TE STEAM in the higher signal‐to‐noise ratio of the H1‐α‐glucose peak (mean ± SD 7.9 ± 2.5, P < 0.001). The conventional analysis overfitted the H1‐α‐glucose peak. The individual CVs of glucose quantification by detecting the H1‐α‐glucose peak were smaller than the corresponding CRLBs. Data Conclusion: Cerebral glucose concentration is quantitated to be 1.07 mM by detecting the H1‐α‐glucose peak in the semi‐LASER spectra. Despite requiring long scan times, detecting the H1‐α‐glucose peak allows true glucose quantification free from the influence of overlapping taurine and macromolecule signals. Evidence Level: 2 Technical Efficacy Stage: 1 [ABSTRACT FROM AUTHOR]

Rationale and Objectives: Phase resolved functional lung (PREFUL) magnetic resonance imaging (MRI) is a free-breathing 1H-based technique that produces maps of fractional ventilation (FV). This study compared ventilation defect percent (VDP) calculated using PREFUL to hyperpolarized (HP) 129Xe MRI and pulmonary function tests in pediatric cystic fibrosis (CF).Materials and Methods: 27 pediatric participants were recruited (mean age 13.0 ± 2.7), including 6 with clinically stable CF, 11 CF patients undergoing a pulmonary exacerbation (PEx), and 10 healthy controls. Spirometry was performed to measure forced expiratory volume in 1 second (FEV1), along with nitrogen multiple breath washout to measure lung clearance index (LCI). VDP was calculated from single central coronal slice PREFUL FV maps and the corresponding HP 129Xe slice.Results: The stable CF group had a normal FEV1 (p = 0.41) and elevated LCI (p = 0.007). The CF PEx group had a decreased FEV1 (p < 0.0001) and elevated LCI (p < 0.0001). PREFUL and HP 129Xe VDP were significantly different between the CF PEx and healthy groups (p < 0.05). In the stable CF group, PREFUL and HP 129Xe VDP were not significantly different from the healthy group (p = 0.18 and 0.08, respectively). There was a correlation between PREFUL and HP 129Xe VDP (R2 = 0.31, p = 0.004), and both parameters were significantly correlated with FEV1 and LCI.Conclusion: PREFUL MRI is feasible in pediatric CF, distinguishes patients undergoing pulmonary exacerbations compared to healthy subjects, and correlates with HP 129Xe MRI as well as functional measures of disease severity. PREFUL MRI does not require breath-holds and is straight forward to implement on any MRI scanner. [ABSTRACT FROM AUTHOR]

Background: The latest generation of interactive cardiac magnetic resonance (MR) scanners has made cardiac interventions with real-time MRI possible. To date, cardiac MRI has been mostly applied to measure myocardial perfusion, viability, and regional function, but now the application of cardiac MRI can be extended to cardiovascular interventions. The purpose of this article is to illustrate the potential of MRI in stem cell therapy for cardiac restoration. Methods: We have applied MRI to (1) interactively target myocardial injections with a novel stem cell delivery catheter, and to compare gadolinium/blue dye injections to pathology; (2) assess myocardial perfusion with MR first pass imaging in an infarct model treated with stem cell therapy versus control animals; (3) measure regional functional changes using myocardial tissue tagging in the same animals. Results: We were able to demonstrate the feasibility and safety of myocardial injections under MR fluoroscopy. The intramyocardial distribution of the blue dye at necropsy correlated well with the extent of gadolinium, as detected with a three-dimensional inversion recovery MR pulse sequence for late enhancement immediately after contrast injection. Preliminary results show that myocardial perfusion reserve and regional wall motion improved in the stem-cell-treated group, compared to a control group. Conclusions: These preliminary results suggest that (1) injections into the LV myocardium can be performed under real-time MRI guidance using a directed catheter approach, and (2) regional myocardial perfusion and function, measured with MRI, both improve after stem cell therapy. This ongoing study demonstrates the potential of MRI for image-guided interventions, combined with detailed evaluation of anatomy, function, perfusion, and viability. (J Interven Cardiol 2004;17:37–46) [ABSTRACT FROM AUTHOR]

Background: Sensitive detection and quantification of cerebral glucose is desired., Purpose: To quantify cerebral glucose by detecting the H1-α-glucose peak at 5.23 ppm in 1 H magnetic resonance spectroscopy at 7 T., Study Type: Prospective., Subjects: Twenty-eight non-fasted healthy subjects (aged 20-28 years)., Field Strength/sequence: Short echo time stimulated echo acquisition mode (short-TE STEAM) and semi-localized by adiabatic selective refocusing (semi-LASER) at 7 T., Assessment: Single voxel spectra were obtained from the posterior cingulate cortex (27-mL) using a 32-channel head coil. The H1-α-glucose peak in the spectrum with retrospective removal of the residual water peak was fitted using LCModel with a glucose basis set of only the H1-α-glucose peak. Conventional spectral analysis was performed with a glucose basis set of a full spectral pattern of glucose, also. Fitting precision was evaluated with Cramér-Rao lower bounds (CRLBs). The repeatability of glucose quantification via the semi-LASER sequence was tested., Statistical Tests: Paired or Welch's t-test were used for normally distributed values. A P value of <0.05 was considered significant. The repeatability of measures was analyzed using coefficient of variation (CV)., Results: Removal of the residual water peak improved the flatness and stability of baselines around the H1-α-glucose peak and reduced CRLBs for fitting the H1-α-glucose peak. The semi-LASER sequence was superior to the short-TE STEAM in the higher signal-to-noise ratio of the H1-α-glucose peak (mean ± SD 7.9 ± 2.5, P < 0.001). The conventional analysis overfitted the H1-α-glucose peak. The individual CVs of glucose quantification by detecting the H1-α-glucose peak were smaller than the corresponding CRLBs., Data Conclusion: Cerebral glucose concentration is quantitated to be 1.07 mM by detecting the H1-α-glucose peak in the semi-LASER spectra. Despite requiring long scan times, detecting the H1-α-glucose peak allows true glucose quantification free from the influence of overlapping taurine and macromolecule signals., Evidence Level: 2 TECHNICAL EFFICACY STAGE: 1., (© 2023 International Society for Magnetic Resonance in Medicine.)