Analysis of C9orf72 repeat expansion in 563 Japanese patients with amyotrophic lateral sclerosis.

Recently, a hexanucleotide repeat expansion in C9orf72 was identified as the most common cause of both sporadic and familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia in Western populations. We analyzed 563 Japanese patients with ALS (552 sporadic and 11 familial) using fluorescent fragment-length analysis of C9orf72 and repeat-primed polymerase chain reaction analysis. Haplotype analysis was performed for 42 single nucleotide polymorphisms in patients with C9orf72 repeat expansion. C9orf72 repeat expansion was found in 2 patients with sporadic ALS (2/552 = 0.4%) and no patients with familial ALS (0/11 = 0%). In the probands' families, 1 primary progressive aphasia patient and 1 asymptomatic 76-year-old individual exhibited C9orf72 repeat expansion. All of the patients with the C9orf72 repeat expansion carried the 20-single nucleotide polymorphism consensus risk haplotype. The frequency of the C9orf72 repeat expansion among Japanese patients is much lower than in Western populations. The existence of a 76-year-old asymptomatic carrier supported the notion of incomplete penetrance. The C9orf72 mutation should be analyzed in sporadic ALS patients after determining their family histories not only of frontotemporal dementia but also of primary progressive aphasia.

[Clinical evaluation of 3D delayed-enhancement MRI using parallel imaging in the assessment of myocardial viability].

This study aimed to evaluate the efficacy of breath-hold three-dimensional (3D)delayed-enhancement MRI using parallel imaging in terms of the effect of parallel imaging on the image quality and visualization of myocardial infarction. Twenty-two patients (17 men and 5 women) with suspected myocardial infarction underwent breath-hold 3D late-enhanced viability examination at least 30 days after occurrence. All patients underwent a Tl-scintigraphy examination. First, 10 patients were examined without applying parallel imaging, then the next 12 patients were studied using parallel imaging. All 3D late-enhanced images at the short axis were acquired 10, 15, and 20 min after an injection of contrast agent, and both the long axis and the four-chamber views were acquired after 15 min. In quantitative analysis, the late-enhanced myocardial images at 10, 15, and 20 min showed higher contrast-to-noise ratios (CNR) in parallel imaging than those with no parallel imaging. During the time-intensity curve of the myocardium, no significant change was observed at 10 or 15 min; however, marked signal reduction was observed at 20 min. In diagnostic evaluation, images obtained with parallel imaging were superior to those without parallel imaging. In general, the application of parallel imaging reduces acquisition time with an expense of reduction in SNR. However, the breath-hold 3D late-enhanced images with parallel imaging showed no apparent SNR reduction. Furthermore, parallel imaging provided clear edge definition between the infarction and the normal region. The reduction of acquisition time with parallel imaging may be less susceptible to fast cardiac motion. In conclusion, breath-hold 3D delayed-enhancement MRI using parallel imaging was highly evaluated in our study and may show promise in clinical application.