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1.
Investigative Magnetic Resonance Imaging ; : 210-222, 2017.
Article in English | WPRIM | ID: wpr-119939

ABSTRACT

PURPOSE: To develop a novel combination of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) with integrated SSFP (CAIPI-iSSFP) for accelerated SSFP imaging without banding artifacts at 3T. MATERIALS AND METHODS: CAIPI-iSSFP was developed by adding a dephasing gradient to the balanced SSFP (bSSFP) pulse sequence with a gradient area that results in 2π dephasing across a single pixel. Extended phase graph (EPG) simulations were performed to show the signal behaviors of iSSFP, bSSFP, and RF-spoiled gradient echo (SPGR) sequences. In vivo experiments were performed for brain and abdominal imaging at 3T with simultaneous multi-slice (SMS) acceleration factors of 2, 3 and 4 with CAIPI-iSSFP and CAIPI-bSSFP. The image quality was evaluated by measuring the relative contrast-to-noise ratio (CNR) and by qualitatively assessing banding artifact removal in the brain. RESULTS: Banding artifacts were removed using CAIPI-iSSFP compared to CAIPI-bSSFP up to an SMS factor of 4 and 3 on brain and liver imaging, respectively. The relative CNRs between gray and white matter were on average 18% lower in CAIPI-iSSFP compared to that of CAIPI-bSSFP. CONCLUSION: This study demonstrated that CAIPI-iSSFP provides up to a factor of four acceleration, while minimizing the banding artifacts with up to a 20% decrease in the relative CNR.


Subject(s)
Acceleration , Artifacts , Brain , Liver , White Matter
2.
Psychol. neurosci. (Impr.) ; 2(2): 189-193, Dec. 2009. ilus, tab
Article in English | LILACS | ID: lil-574096

ABSTRACT

Changes in cortical thickness can be related to neuropsychiatric disorders and neurodegenerative processes. Previous studies have been conducted to characterize the pattern of changes in cortical thickness in several psychiatric diseases. The aim of the present study was to evaluate changes in cortical thickness with magnetic resonance imaging (MRI) in patients with bipolar disorder. Twenty-seven patients with bipolar disorder (14 male, 36.0 ± 16.2 years old; 13 female, 41.6 ± 10.7 years old) and 40 healthy controls (16 male, 36.0 ± 10.5 years old; 24 female, 37.0 ± 4.7 years old) underwent 3T MRI. Sagittal T1-weighted magnetization prepared rapid acquisition gradient echo images were acquired (voxel size, 1.33 mm³; 128 slices; in-plane matrix resolution, 256 × 256; flip angle, 7º; repetition time, 2530 ms; echo time, 3.39 ms; inversion time, 1100 ms). Cortical segmentation was performed using FreeSurfer 4.0.5. The results indicated both thinning and thickening of the cerebral cortex in patients with bipolar disorder compared with controls, depending on gender. Significant (p < .01) thickening was observed in the right hemisphere superior-parietal cortex in female patients with bipolar disorder, and significant (p < .05) thinning was observed in the left hemisphere caudal-anterior cingulate in male patients with bipolar disorder. The other regions did not show significant differences. The results suggest that an analysis of cortical thickness with MRI in patients with bipolar disorder may allow identification of areas that may be morphologically changed compared with controls. Demonstration of these alterations will elucidate the pathophysiology of bipolar disorder and may contribute to better therapies for this disorder.


Subject(s)
Humans , Male , Female , Adult , Cerebral Cortex , Magnetic Resonance Imaging , Bipolar Disorder/psychology
3.
IJRM-Iranian Journal of Reproductive Medicine. 2005; 3 (2): 83-89
in English | IMEMR | ID: emr-172902

ABSTRACT

About 90% of the world's contraceptive users are women. This gender-based usage has occurred due to the emphasis of family planning programs and contraception research. Condom, vasectomy and withdrawal are the only male contraception devices available with less assurance for men. For new male contraceptive to have an impact, they must be acceptable to both men and women, as well as effective. A hormonal method will likely come to the market within the next few years. It is necessary to use biologically active botanical substances or fertility-regulating agents of plant origin which are ecofriendly. The epididymis is a site which can be exploited for male contraception without undue side effects. It was therefore of interest to investigate the effect of biologically active botanical ecofriendly plants such as Azadirchta Indica [neem] seed alcoholic extract as an efficient and competent male contraceptive on male mouse epididymis. In this experimental case control study sixty adult healthy mice divided into two groups of 40 as the control and 20 as the treated group. The treated group was administered by Iranian Botanical Azadirachta Indica seed alcoholic extract, cultivated at Dashteh Moghan [Ardabil province]. The seeds were extracted with ethanol then administered first 50 mg/kg body weight /day then 100 mg/kg body weight/day orally for 15 days, following WHO guide lines [MB-50]. The target organ, epididymis parameters viz. sperm motility, sperm count fertility rate, Scanning Electron Microscopic [SEM] morphology of spermatozoa and ATPase activity of epididymis of the two groups were compared. The 50 mg/kg body weight [BW] day showed no significant change in epididymis sperm motility, as compare to the control. Therefore the dose was changed to 100 mg/kg BW/day for 15 days. The body and organ weights [epididymis] of the treated animals were not significantly changed as compare to control group [p>0.05]. The treatment brought about a significant reduction in fertility rate when normal cycling female mice were mated with treated males [p<0.001]. Decline in ATPase activity in caput and cauda epididymis was observed [p<0.001]. SEM photographs showed spermatozoa with abnormal head and bent mid-piece region. Decrease in ATPase activity could be attributed to androgen dependent parameters. However, the fertility rate was also significantly reduced which can be due to the decrease in cauda epididymal sperm motility and their morphological abnormalities. Since the effect on epididymal sperm motility and morphology was manifested in short period of 15 days, it is evident that the extract has potential as an antifertility agent. As this extract do not cause change in the body and organ weight, it is likely that no effect occurred on electrolyte balance

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