Reproducibility of CBF using pCASL

Purpose : To determine the reproducibility of corrected quantitative cerebral blood flow (qCBF) through measurement of transit flow time using multi-delay three-dimensional pseudo-continuous arterial spin labeling (pCASL) in healthy men and women and to evaluate the differences in qCBF between not only men and women, but also the follicular and luteal phases of the women’s menstrual cycle. Methods : The participants were 16 healthy volunteers (8 men and 8 women ; mean age, 25.3 years). Two MRI were conducted for all participants ; female participants were conducted in the follicular and luteal phases. The reproducibility of qCBF values was evaluated by the intraclass correlation coefficient (ICC) and differences between the two groups were estimated by voxel-based morphometry (VBM) analysis. Results : The qCBF values were lower in men than in women, and those in females were significantly different between the follicular and luteal phases (P < 0.05). In VBM analysis, the qCBF values of the lower frontal lobes were significantly higher in women than in men (P < 0.05). The qCBF values of the frontal pole were significantly higher in the follicular phase than in the luteal phase (P < 0.01). Conclusion : Multi-delay pCASL can reveal physiological and sex differences in cerebral perfusion

MR perfusion imaging by alternate slab width inversion recovery arterial spin labeling (AIRASL): a technique with higher signal-to-noise ratio at 3.0 T

Object: To propose a new arterial spin labeling (ASL) perfusion-imaging method (alternate slab width inversion recovery ASL: AIRASL) that takes advantage of the qualities of 3.0 T. Materials and methods: AIRASL utilizes alternate slab width IR pulses for labeling blood to obtain a higher signal-to-noise ratio (SNR). Numerical simulations were used to evaluate perfusion signals. In vivo studies were performed to show the feasibility of AIRASL on five healthy subjects. We performed a statistical analysis of the differences in perfusion SNR measurements between flow-sensitive alternating inversion recovery (FAIR) and AIRASL. Results: In signal simulation, the signal obtained by AIRASL at 3.0 and 1.5 T was 1.14 and 0.85%, respectively, whereas the signal obtained by FAIR at 3.0 and 1.5 T was 0.57 and 0.47%, respectively. In an in vivo study, the SNR of FAIR (3.0 T) and FAIR (1.5 T) were 1.73 ± 0.49 and 1.02 ± 0.20, respectively, whereas the SNRs of AIRASL (3.0 T) and AIRASL (1.5 T) were 3.93 ± 1.65 and 1.34 ± 0.31, respectively. SNR in AIRASL at 3.0 T was significantly greater than that in FAIR at 3.0 T. Conclusion: The most significant potential advantage of AIRASL is its high SNR, which takes advantage of the qualities of 3.0 T. This sequence can be easily applied in the clinical setting and will enable ASL to become more relevant for clinical application. © 2012 ESMRMB.Article in Press エンバーゴ設定 Thesis of Fujiwara, Yasuhiro / 藤原 康博 博士学位論文(金沢大学 / 大学院医薬保健学総合研究科

Three-Dimensional Anisotropy Contrast MRI and Functional MRI of the Human Brain: Clinical Application to Assess Pyramidal Tract in Patients with Brain Tumor and Infarction

We describe and evaluate the findings of three-dimensional anisotropy contrast MR axonography (3DAC MRX) and functional MRI (fMRI) in brain tumor and infarction. We obtained diffusion-weighted images (DWI) in 28 patients including 23 brain tumors and 15 acute infarctions located in or near pyramidal tract. Three anisotropic DWIs were transformed into graduations color-coded as red, green or blue, and then composed to form a combined color 3DAC MRX. We also performed functional MRI in 7 of the 28 patients and compared with cortical mapping of 3DAC MRX. 3DAC MRX with 23 brain tumors showed that the ipsilateral pyramidal tract was either discontinuous due to impaired anisotropy (n=8) or compressed due to mass effect (n=15). In 10 patients of acute infarction with motor impairment, pyramidal tract involvement was visually more conspicuous on 3DAC MRX compared to standard DWI. On functional MRI, hand motor activation was observed between blue vertical directional colors of pre- and post central gyrus. In conclusion, 3DAC MRX is a new noninvasive approach for visualization of the white matter neuronal tract and provides the information concerning pyramidal tract involvement

3 Tesla MRI detects accelerated hippocampal volume reduction in postmenopausal women

Purpose To clarify age-related structural changes specific to hippocampal volume by hierarchizing according to age, gender, and menopausal status. Many studies report the neuroprotective effects of estrogen and age-related brain volume changes; however, there are no studies regarding age-related change specific to hippocampal volume in terms of age, gender, and menopausal status. Materials and Methods T1-weighted MR images were obtained in 412 healthy adults divided into eight groups according to age and gender, to analyze brain volume change focusing on hippocampal volume. Results Voxel-based morphometry (VBM) revealed significantly smaller gray matter volume in the hippocampus bilaterally in females aged in their fifties (51 of 59 females were at menopause) compared with females in their forties (3 of 46 females were at menopause). No significant difference was found, however, between female groups in their fifties versus sixties, or sixties versus seventies; or between male groups in their forties versus fifties, fifties versus sixties, or sixties versus seventies. In addition, VBM revealed significant hippocampal volume reduction bilaterally in all postmenopausal women compared with all premenopausal women. Conclusion The results of the current study suggest that the menopause may be associated with hippocampal volume reduction. © 2010 Wiley-Liss, Inc.Thesis of Goto,Masami / 後藤 政実 博士学位論文(金沢大学 / 大学院医薬保健学総合研究科

A Cluster of Respiratory Syncytial Virus Infections in a Hospital Ward for Adult Immunocompromised Patients

Four male patients admitted to the same ward in the first half of September 201Y were identified to have respiratory syncytial virus（RSV）infection. Their ages ranged from 49 to 85 years（median 72.5）. One patient was infected with human immunodeficiency virus and three patients had hematological malignancies. Following immuno-chromatological testing with a nasal cavity swab, RSV infection was diagnosed. Although blood and sputum cultures were performed in three patients, no significant bacteria were detected. Two cases responded to supportive therapy. However, one patient died secondary to multiple myeloma, and another patient developed pneumonia and died with an exacerbation of leukemia. RSV infections in immunocompromised hosts are associated with a poor prognosis. Early diagnosis will facilitate isolation of infected individuals to prevent hospital outbreaks