Reference Values of Native T1 at 3T Cardiac Magnetic Resonance—Standardization Considerations between Different Vendors

This study aimed at establishing native T1 reference values for a Canon Vantage Galan 3T system and comparing them with previously published values from different vendors. A total of 20 healthy volunteers (55% Women; 33.9 ± 11.1 years) underwent left ventricular T1 mapping at 3T MR. A MOLLI 5(3)3 sequence was used, acquiring three short-axis slices. Native T1 values are shown as means (±standard deviation) and Student’s independent samples t-test was used to test gender differences in T1 values. Pearson’s correlation coefficient analysis was used to compare two processes of T1 analysis. The results show a global native T1 mean value of 1124.9 ± 55.2 ms (exponential analysis), that of women being statistically higher than men (1163 ± 30.5 vs. 1077.9 ± 39.5 ms, respectively; p < 0.001). There were no specific tendencies for T1 times in different ventricular slices. We found a strong correlation (0.977, p < 0.001) with T1 times derived from parametric maps (1136.4 ± 60.2 ms). Native T1 reference values for a Canon 3T scanner were provided, and they are on par with those already reported from other vendors for a similar sequence. We also found a correlation between native T1 and gender, with higher values for women.

Brain Volume Alterations Using 3tesla Magnetic Resonance and Neuropsychological Findings in Gaucher Disease Patients

Gaucher Disease (GD) is a metabolic inherited disorder, that classically includes three clinical phenotypes. Type I GD (GD1) is considered as a non-neuronopathic variant and can mimic a hematologic disease; type II (GD2) is classified as an acute neuropathic form and type III (GD3) is characterized by a slower and progressive neurological involvement. A protective role of N370S mutation against neurological impairment had been previously hypothesized in GD1, however, increasing data and our experience show that patients with GD1 may present clinical signs of parkinsonism, frequently combined with cognitive impairment and behavioral alterations. Structural brain changes associated with cognitive impairments in GD patients, especially type I, has not yet been reported. The prospective study, called SENOPRO_GAUCHER, has investigated in depth, the neurological status in GD patients using a multidisciplinary approach, including 3Tesla magnetic resonance (3T MR). This study was approved by our Ethics Committee. Baseline data on neurological, psychological, psychiatric, somatosensory, and motor evaluations, and electroencephalography (EEG) surprisingly revealed two, or more, clinical and/or instrumental, neurological signs in all GD1 patients, and a wide spectrum of neurological abnormalities in all GD3 patients. We, hereby, report the results of investigations on brain structure of GD patients, compared to that of healthy subjects, using 3T MR, in order to evaluate whether brain alterations can predict neurocognitive impairment in GD patients, especially GD1. Out of 22 GD patients, assessed for neuropsychological and psychiatric functions, 19 (17 GD1, 2 GD3, median age = 44, range 17 - 68 years) underwent 3T MR examination. Regarding genotyping, all but one of the 17 GD1 patients was N370S mutation heterozygous. A Voxel-based Morphometry (VBM) analysis was performed to investigate brain structure in the 19 GD patients and in 19 healthy subjects with no neurological or neuropsychiatric disease. The healthy subjects, matched to patients by age, sex, and education, in addition to 3T MR, underwent neuropsychological assessment using Mini-Mental State Exam and Mental Deterioration Battery, to evaluate cognitive functions and mental deterioration, respectively. Qualitative MR examinations revealed unspecific abnormalities in 7/17 GD1 patients. In particular, cortical and/or subcortical areas of gliosis (4 patients), vascular ectasia extended from the left frontal surface of the brain to the lateral ventricle (1 patient), dilation of perivascular spaces in the sub-cortical and nucleus-basal area (1 patient), diffuse suffering of the brain white matter due to a chronic ischemic vascular damage (1 patient) were found. Concurrently, results of the VBM analysis revealed that a set of regions, mostly located in the prefrontal and parieto-occipital cortex, were significantly reduced in GD patients, compared to healthy subjects. The most affected regions included the frontal eye fields, the dorso-lateral prefrontal cortex, the posterior cingulate cortex, and the V3B area. Psychological and psychiatric evaluations underlined anxiety, depression, and somatic concerns in 10/17 GD1 patients, combined with cognitive impairments in two of them. Moreover, 1/2 GD3 and 5/17 GD1 patients showed cognitive impairments in attention, language, short-term memory, and executive cognitive functions. The local brain volume reductions, detected in GD1 patients, were in line with the cognitive impairments resulted in the neuropsychological assessment. Cortical reductions of fronto-parietal regions, responsible for the planning and execution of movements, are compatible with impairments in executive functions (digit-span) and visuo-spatial memory, found in GD1 patients. Moreover, impairments in short-term memory observed in GD1 patients are compatible with cortical reductions in the frontal cortex found by the VBM analysis. In conclusion, focal brain differences found between GD1 patients and healthy subjects may predict and clarify the cognitive impairments and behavioural alterations observed in GD patients. The brain structural analyses, associated with neuropsychological assessment, suggest that a multidisciplinary approach is necessary in evaluating GD1 patients. Disclosures Giona: Sanofi Genzyme: Consultancy, Research Funding, Speakers Bureau; Takeda: Speakers Bureau; Novartis: Consultancy.

Visualization of wrist anatomy—a comparison between 7T and 3T MRI

Objective Injuries to the wrist are, due to its small size and complex anatomical structures, difficult to assess by MR, and surgical interventions such as diagnostic arthroscopy are often necessary. Therefore, improved visualization using non-invasive methods could be of clinical value. As a first step of improvement, the purpose of this study was to evaluate visualization of anatomical structures at 7T compared with 3T MR. Methods Eighteen healthy volunteers (three males and three females from each age decade between 20 and 49 years) were examined with 7T and 3T MR. Four musculoskeletal radiologists graded 2D and 3D images on a five-level grading scale for visibility of ligaments, cartilage, nerves, trabecular bone, and tendons, as well as overall image quality (i.e., edge sharpness, perceived tissue contrast, and presence of artefacts). Statistical analysis was done using a visual grading characteristics (VGC) analysis. Results Visibility of cartilage, trabecular bone, tendons, nerves, and ligaments was graded significantly higher at 7T with an area under the curve (AUCVGC) of 0.62–0.88 (95% confidence interval [CI] 0.50–0.97, p = < 0.0001–0.03) using either 2D or 3D imaging. Imaging with 3T was not graded as superior to 7T for any structure. Image quality was also significantly superior at 7T, except for artefacts, where no significant differences were found. Conclusions Tendons, trabecular bone, nerves, and ligaments were all significantly better visualized at 7T compared to 3T. Key Points • MRI of the wrist at 7T with a commercially available wrist coil is feasible at similar acquisition times as for 3T MRI. • The current study showed 7T to be superior to 3T in the visualization of anatomical structures of the wrist, including ligaments, tendons, nerves, and trabecular bone. • Image quality was significantly superior at 7T, except for artefacts, where no significant differences were found.