Resonance Imaging
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2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Cecilia Cavalli ◽  
Claudia Maggi ◽  
Sebastiana Gambarini ◽  
Anna Fichera ◽  
Amerigo Santoro ◽  
...  

Abstract Objectives We aimed to assess the performance of ultrasound (US) and magnetic resonance imaging (MRI) signs for antenatal detection of placenta accreta spectrum (PAS) disorders in women with placenta previa (placental edge ≤2 cm from the internal uterine orifice, ≥260/7 weeks’ gestation) with and without a history of previous Caesarean section. Methods Single center prospective observational study. US suspicion of PAS was raised in the presence of obliteration of the hypoechoic space between uterus and placenta, interruption of the hyperechoic uterine-bladder interface and/or turbulent placental lacunae on color Doppler. All MRI studies were blindly evaluated by a single operator. PAS was defined as clinically significant when histopathological diagnosis was associated with at least one of: intrauterine balloon placement, compressive uterine sutures, peripartum hysterectomy, uterine or hypogastric artery ligature, uterine artery embolization. Results A total of 39 women were included: 7/39 had clinically significant PAS. There were 6/18 cases of PAS with anterior placenta: hypoechoic space interruption and placental lacunae were the most sensitive sonographic signs (83%), while abnormal hyperechoic interface was the most specific (83%). On MRI, focal myometrial interruption and T2 intraplacental dark bands showed the best sensitivity (83%), bladder tenting had the best specificity (100%). 1/21 women with posterior placenta had PAS. There was substantial agreement between US and MRI in patients with anterior placenta (κ=0.78). Conclusions US and MRI agreement in antenatal diagnosis of clinically significant PAS was maximal in high-risk women. Placental lacunae on ultrasound scan and T2 intraplacental hypointense bands on MRI should trigger the suspicion of PAS.


2021 ◽  
Author(s):  
Osama Hamadelseed ◽  
Thomas Skutella

Abstract INTRODUCTION: Down syndrome (DS) is the most common genetic cause of intellectual disability. Here, we use magnetic resonance imaging (MRI) on children and adults with DS to characterize changes in the volume of specific brain structures involved in memory and language and their relationship to features of cognitive-behavioral phenotypes.METHODS: Thirteen children and adults with the DS phenotype and 12 age- and gender-matched healthy controls were analyzed by MRI and underwent a psychological evaluation for language and cognitive abilities.RESULTS: The neuropsychological profile of DS patients showed deficits in different cognition and language domains in correlation with reduced volumes of specific regional and subregional brain structures.CONCLUSIONS: The memory functions and language skills affected in our DS patients correlate significantly with the reduced volume of specific brain regions, allowing us to understand DS's cognitive-behavioral phenotype. Our results provide an essential basis for early intervention and the design of rehabilitation management protocols.


2021 ◽  
Vol 11 ◽  
pp. 65
Author(s):  
Kenichi Yamada ◽  
Junichi Yoshimura ◽  
Masaki Watanabe ◽  
Kiyotaka Suzuki

Ultra-high field magnetic resonance imaging (MRI) has been introduced for use in pediatric developmental neurology. While higher magnetic fields have certain advantages, optimized techniques with specific considerations are required to ensure rational and safe use in children and those with pediatric neurological disorders (PNDs). Here, we summarize our initial experience with clinical translational studies that utilized 7 tesla (T)-MRI in the fields of developmental neurology. T2-reversed images and three-dimensional anisotropy contrast imaging enabled the depiction of targeted pathological brain structures with better spatial resolution. Diffusion imaging and susceptibility-weighted imaging enabled visualization of intracortical, subcortical, and intratumoral microstructures in vivo within highly limited scan times appropriate for patients with PNDs. 7T-MRI appears to have significant potential to enhance the depiction of the structural and functional properties of the brain, particularly those associated with atypical brain development.


2021 ◽  
pp. 028418512110582
Author(s):  
Takumi Yokohama ◽  
Motoyuki Iwasaki ◽  
Daisuke Oura ◽  
Sho Furuya ◽  
Yoshimasa Niiya

Background Recent studies have indicated that injuries such as muscle tears modify the microstructural integrity of muscle, leading to substantial alterations in measured diffusion parameters. Therefore, the fractional anisotropy (FA) value decreases. However, we hypothesized that soft tissue, such as muscle tissue, undergoes reversible changes under conditions of compression without fiber injury. Purpose To evaluate the FA change due to compression in muscle tissue without fiber injury. Material and Methods Diffusion tensor imaging (DTI) was performed on both feet of 10 healthy volunteers (mean age = 35.0 ± 10.39 years; age range = 23–52 years) using a 3.0-T magnetic resonance imaging (MRI) scanner with an eight-channel phased array knee coil. An MRI-compatible sphygmomanometer was applied to the individuals’ lower legs and individuals were placed in a compressed state. Then, rest intervals of 5 min were set in re-rest state after compression. The FA value, apparent diffusion coefficient (ADC), and eigenvalues (λ1, λ2, λ3) of the gastrocnemius and soleus muscle were measured at each state. Results The mean FA values increased in all muscles in a compressed state, while the mean λ3 decreased. In all muscles, significant differences were found between the rest and compressed states in terms of mean FA and λ3 ( P < 0.0001). Conclusion We confirmed the reversibility of the DTI metrics, which suggests that there was no muscle injury during this study. In cases of compression without fiber injury, the FA value increases, because fibers are strongly aligned in the longitudinal direction.


Author(s):  
Nora-Josefin Breutigam ◽  
Matthias Günther ◽  
Daniel Christopher Hoinkiss ◽  
Klaus Eickel ◽  
Robert Frost ◽  
...  

Abstract Object In this work, we present a technique called simultaneous multi-contrast imaging (SMC) to acquire multiple contrasts within a single measurement. Simultaneous multi-slice imaging (SMS) shortens scan time by allowing the repetition time (TR) to be reduced for a given number of slices. SMC imaging preserves TR, while combining different scan types into a single acquisition. This technique offers new opportunities in clinical protocols where examination time is a critical factor and multiple image contrasts must be acquired. Materials and methods High-resolution, navigator-corrected, diffusion-weighted imaging was performed simultaneously with T2*-weighted acquisition at 3 T in a phantom and in five healthy subjects using an adapted readout-segmented EPI sequence (rs-EPI). Results The results demonstrated that simultaneous acquisition of two contrasts (here diffusion-weighted imaging and T2*-weighting) with SMC imaging is feasible with robust separation of contrasts and minimal effect on image quality. Discussion The simultaneous acquisition of multiple contrasts reduces the overall examination time and there is an inherent registration between contrasts. By using the results of this study to control saturation effects in SMC, the method enables rapid acquisition of distortion-matched and well-registered diffusion-weighted and T2*-weighted imaging, which could support rapid diagnosis and treatment of acute stroke.


2021 ◽  
Author(s):  
Shotaro Fujiwara ◽  
Ryo Ishibashi ◽  
Azumi Tanabe-Ishibashi ◽  
Ryuta Kawashima ◽  
Motoaki Sugiura

Sincere praise reliably conveys positive or negative feedback, while flattery always conveys positive but unreliable feedback. These two praise types have not been compared in terms of communication effectiveness and individual preferences using neuroimaging. Through functional magnetic resonance imaging, we measured brain activity when healthy young participants received sincere praise or flattery after performing a visual search task. Higher activation was observed in the right nucleus accumbens during sincere praise than during flattery, and praise reliability correlated with posterior cingulate cortex activity, implying a motivational effect of sincere praise. In line with this, sincere praise uniquely activated several cortical areas potentially involved in concern regarding others' evaluations. A high praise-seeking tendency was associated with lower activation of the inferior parietal sulcus during sincere praise compared to flattery after poor task performance, potentially reflecting suppression of negative feedback to maintain self-esteem. In summary, the neural dynamics of the motivational and socio-emotional effects of praise differed.


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