scholarly journals Simultaneous Multislice Brain MRI T1 Mapping with Improved Low-Rank Modeling

Tomography ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 545-554
Author(s):  
Sugil Kim ◽  
Suhyung Park
Keyword(s):  
Optimization Problem ◽  
T1 Mapping ◽  
Null Space ◽  
Brain Mri ◽  
Low Rank ◽  
Brain Scans ◽  
Joint Reconstruction ◽  
Simultaneous Multislice ◽  
Acquisition Speed ◽  
Magnetic Resonance Imaging Mri

To accelerate data acquisition speed in magnetic resonance imaging (MRI), multiple slices are simultaneously acquired using multiband pulses. Simultaneous multislice (SMS) imaging typically unfolds slice aliasing from the acquired collapsed slices. In this study, we extended the SMS framework to accelerated MR parameter quantification such as T1 mapping. Assuming that the slice-specific null space and signal subspace are invariant along the parameter dimension, we formulated the SMS framework as a constrained optimization problem under a joint reconstruction framework such that the noise and signal subspaces are used for slice separation and recovery, respectively. The proposed method was validated on 3T MR human brain scans. We successfully demonstrated that the proposed method outperforms competing methods in suppressing aliasing artifacts and noise at high SMS accelerations, thus leading to accurate T1 maps.

An Algorithm Combining Analysis-based Blind Compressed Sensing and Nonlocal Low-rank Constraints for MRI Reconstruction

2019 ◽  
Vol 15 (3) ◽  
pp. 281-291 ◽  
Author(s):  
Mei Sun ◽  
Jinxu Tao ◽  
Zhongfu Ye ◽  
Bensheng Qiu ◽  
Jinzhang Xu ◽  
...  
Keyword(s):  
Compressed Sensing ◽  
Signal Reconstruction ◽  
Low Rank ◽  
Mr Images ◽  
Scanning Time ◽  
Previous State ◽  
Rank Approximation ◽  
Mri Reconstruction ◽  
Magnetic Resonance Imaging Mri ◽  
Rank Constraints

Background: In order to overcome the limitation of long scanning time, compressive sensing (CS) technology exploits the sparsity of image in some transform domain to reduce the amount of acquired data. Therefore, CS has been widely used in magnetic resonance imaging (MRI) reconstruction. </P><P> Discussion: Blind compressed sensing enables to recover the image successfully from highly under- sampled measurements, because of the data-driven adaption of the unknown transform basis priori. Moreover, analysis-based blind compressed sensing often leads to more efficient signal reconstruction with less time than synthesis-based blind compressed sensing. Recently, some experiments have shown that nonlocal low-rank property has the ability to preserve the details of the image for MRI reconstruction. Methods: Here, we focus on analysis-based blind compressed sensing, and combine it with additional nonlocal low-rank constraint to achieve better MR images from fewer measurements. Instead of nuclear norm, we exploit non-convex Schatten p-functionals for the rank approximation. </P><P> Results & Conclusion: Simulation results indicate that the proposed approach performs better than the previous state-of-the-art algorithms.

scholarly journals Methomyl poisoning presenting with decorticate posture and cortical blindness

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Chih-Ming Lin
Keyword(s):  
Brain Mri ◽  
Vital Signs ◽  
Altered Mental Status ◽  
Cortical Blindness ◽  
High Signal ◽  
Blurred Vision ◽  
Cerebral Disease ◽  
Cerebral Magnetic Resonance Imaging ◽  
Neurological Effects ◽  
Magnetic Resonance Imaging Mri

Methomyl is a potent pesticide that is widely used in the field of agriculture. The systemic toxic effects of methomyl have been well described. However, the neurological effects of methomyl intoxication are not well understood. In this study, we report a 61-year-old Taiwanese man sent to our emergency department because of altered mental status. His family stated that he had consumed liquid methomyl in a suicide attempt. He was provided cardiopulmonary resuscitation because of unstable vital signs. He was then sent to an intensive care unit for close observation. On the second day of admission, he regained consciousness but exhibited irregular limb and torso posture. On the sixth day, he started to complain of blurred vision. An ophthalmologist was consulted but no obvious abnormalities could be identified. On suspicion of cerebral disease, a neurologist was consulted. Further examination revealed cortical blindness and decorticate posture. Cerebral magnetic resonance imaging (MRI) was arranged, which identified bilateral occipital regions lesions. The patient was administered normal saline and treated with aspirin and piracetam for 3 weeks in hospital. During the treatment period, his symptom of cortical blindness resolved, whereas his decorticate posture was refractory. Follow-up brain MRI results supported our clinical observations by indicating the disappearance of the bilateral occipital lesions and symmetrical putaminal high signal abnormalities. In this article, we briefly discuss the possible mechanisms underlying the cerebral effects of methomyl poisoning. Our study can provide clinicians with information on the manifestations of methomyl intoxication and an appropriate treatment direction.

Pediatric Reversible Cerebral Vasoconstriction Syndrome: Two Unique Cases with a Review of all Reported Children

2021 ◽  
Author(s):  
Neelu Desai ◽  
Rahul Badheka ◽  
Nitin Shah ◽  
Vrajesh Udani
Keyword(s):  
Magnetic Resonance ◽  
Cerebral Arteries ◽  
Brain Mri ◽  
Brain Magnetic Resonance Imaging ◽  
Reversible Cerebral Vasoconstriction Syndrome ◽  
Neurological Deficits ◽  
Cerebral Vasoconstriction ◽  
Magnetic Resonance Imaging Mri ◽  
Reversible Encephalopathy ◽  
Mr Angiogram

AbstractReversible cerebral vasoconstriction syndrome (RCVS) has been well described in adults, but pediatric cases are yet under recognized. We describe two children with RCVS and review similar already published pediatric cases. The first patient was a 10-year-old girl who presented with severe headaches and seizures 3 days after blood transfusion. Brain magnetic resonance imaging (MRI) showed changes compatible with posterior reversible encephalopathy syndrome and subarachnoid hemorrhage. Magnetic resonance angiogram showed diffuse vasoconstriction of multiple cerebral arteries. The second patient was a 9-year-old boy who presented with severe thunderclap headaches. Brain MRI showed isolated intraventricular hemorrhage. Computed tomography/MR angiogram and digital subtraction angiogram were normal. A week later, he developed focal neurological deficits. Repeated MR angiogram showed diffuse vasospasm of multiple intracranial arteries. Both children recovered completely. A clinico-radiological review of previously reported childhood RCVS is provided.

scholarly journals Prevalence and Clinical Implications of Incidentally Detected Parotid Lesions as Blind Spot on Brain MRI: A Single-Center Experience

Medicina ◽  
2021 ◽  
Vol 57 (8) ◽  
pp. 836
Author(s):  
In-Chul Nam ◽  
Hye-Jin Baek ◽  
Kyeong-Hwa Ryu ◽  
Jin-Il Moon ◽  
Eun Cho ◽  
...  
Keyword(s):  
Brain Mri ◽  
Brain Magnetic Resonance Imaging ◽  
Blind Spot ◽  
Clinical Implications ◽  
Single Center Experience ◽  
Superficial Lobe ◽  
Mean Size ◽  
Magnetic Resonance Imaging Mri ◽  
Clinical Awareness ◽  
Low Prevalence

Background and objective: This study was conducted to assess the prevalence and clinical implications of parotid lesions detected incidentally during brain magnetic resonance imaging (MRI) examination. Materials and Methods: Between February 2016 and February 2021, we identified 86 lesions in the brain MRI reports of 84 patients that contained the words “parotid gland” or “PG”. Of these, we finally included 49 lesions involving 45 patients following histopathological confirmation. Results: Based on the laboratory, radiological or histopathological findings, the prevalence of incidental parotid lesions was low (1.2%). Among the 45 study patients, 41 (91.1%) had unilateral lesions, and the majority of the lesions were located in the superficial lobe (40/49, 81.6%). The mean size of the parotid lesions was 1.3 cm ± 0.4 cm (range, 0.5 cm–2.8 cm). Of these, 46 parotid lesions (93.9%) were benign, whereas the remaining three lesions were malignant (6.1%). Conclusions: Despite the low prevalence and incidence of malignancy associated with incidental parotid lesions detected on brain MRI, the clinical implications are potentially significant. Therefore, clinical awareness and appropriate imaging work-up of these lesions are important for accurate diagnosis and timely management.

scholarly journals Infant and Child MRI: A Review of Scanning Procedures

2021 ◽  
Vol 15 ◽  
Author(s):  
Anni Copeland ◽  
Eero Silver ◽  
Riikka Korja ◽  
Satu J. Lehtola ◽  
Harri Merisaari ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Brain Mri ◽  
Research Field ◽  
Quality Data ◽  
Birth Cohort Study ◽  
Success Rates ◽  
Older Children ◽  
Factors Affecting ◽  
Scanning Procedure ◽  
Magnetic Resonance Imaging Mri

Magnetic resonance imaging (MRI) is a safe method to examine human brain. However, a typical MR scan is very sensitive to motion, and it requires the subject to lie still during the acquisition, which is a major challenge for pediatric scans. Consequently, in a clinical setting, sedation or general anesthesia is often used. In the research setting including healthy subjects anesthetics are not recommended for ethical reasons and potential longer-term harm. Here we review the methods used to prepare a child for an MRI scan, but also on the techniques and tools used during the scanning to enable a successful scan. Additionally, we critically evaluate how studies have reported the scanning procedure and success of scanning. We searched articles based on special subject headings from PubMed and identified 86 studies using brain MRI in healthy subjects between 0 and 6 years of age. Scan preparations expectedly depended on subject’s age; infants and young children were scanned asleep after feeding and swaddling and older children were scanned awake. Comparing the efficiency of different procedures was difficult because of the heterogeneous reporting of the used methods and the success rates. Based on this review, we recommend more detailed reporting of scanning procedure to help find out which are the factors affecting the success of scanning. In the long term, this could help the research field to get high quality data, but also the clinical field to reduce the use of anesthetics. Finally, we introduce the protocol used in scanning 2 to 5-week-old infants in the FinnBrain Birth Cohort Study, and tips for calming neonates during the scans.

scholarly journals Ensemble classification and segmentation for intracranial metastatic tumors on MRI images based on 2D U-nets

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheng-Chung Li ◽  
Meng-Yun Wu ◽  
Ying-Chou Sun ◽  
Hung-Hsun Chen ◽  
Hsiu-Mei Wu ◽  
...  
Keyword(s):  
Active Contour Model ◽  
Brain Mri ◽  
Gamma Knife Radiosurgery ◽  
Imbalanced Data ◽  
Brain Magnetic Resonance Imaging ◽  
Region Of Interest ◽  
Ensemble Classification ◽  
Metastatic Tumors ◽  
Post Contrast ◽  
Magnetic Resonance Imaging Mri

AbstractThe extraction of brain tumor tissues in 3D Brain Magnetic Resonance Imaging (MRI) plays an important role in diagnosis before the gamma knife radiosurgery (GKRS). In this article, the post-contrast T1 whole-brain MRI images had been collected by Taipei Veterans General Hospital (TVGH) and stored in DICOM format (dated from 1999 to 2018). The proposed method starts with the active contour model to get the region of interest (ROI) automatically and enhance the image contrast. The segmentation models are trained by MRI images with tumors to avoid imbalanced data problem under model construction. In order to achieve this objective, a two-step ensemble approach is used to establish such diagnosis, first, classify whether there is any tumor in the image, and second, segment the intracranial metastatic tumors by ensemble neural networks based on 2D U-Net architecture. The ensemble for classification and segmentation simultaneously also improves segmentation accuracy. The result of classification achieves a F1-measure of $$75.64\%$$ 75.64 % , while the result of segmentation achieves an IoU of $$84.83\%$$ 84.83 % and a DICE score of $$86.21\%$$ 86.21 % . Significantly reduce the time for manual labeling from 30 min to 18 s per patient.

MRI Characteristic of Cerebral White Matter Maturation Patterns in Normal Infants of Assisted Reproductive

2020 ◽  
Author(s):  
Xiaoming Wu ◽  
Junfeng Wang ◽  
Libo Zou ◽  
Xiaojian Cui ◽  
Youcheng Wang ◽  
...  
Keyword(s):  
Brain Development ◽  
Cerebral White Matter ◽  
Vitro Fertilization ◽  
Brain Scans ◽  
Number Of Children ◽  
Significant Difference ◽  
Mri Scans ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

Abstract Background Assisted reproductive technology (ART) such as in-vitro fertilization (IVF) and embryo transfer (ET) has been essential in the treatment of infertility, and the number of children born after these procedures has now passed 5 million worldwide. Children born after medically assisted reproduction are at higher risk of adverse birth outcomes than are children conceived naturally. In this study, we leveraged MRI technology to investigate whether ART pregnancy methods: intracytoplasmic sperm injection (ICSI) and ET have any effect on the brain development of offspring by comparing with the NAT pregnancy method. Methods A total of 75 infants were recruited in the study from 3 conception groups: 25 children born after ICSI, 25 children born after IVF-ET and 25 children born after natural pregnancy. Magnetic resonance imaging (MRI) scans provide exceptionally detailed information on how the human brain changes throughout childhood, adolescence, and old age. The use of MRI in the evaluation of the developing brain is well established. Results The results of routine brain scans on T1WI and T2WI showed that there was no significant difference among the 5-7, 11-13, and 23-25 months of infants among ET, ICSI, and NAT groups. The MRI values fluctuate at different time points indicating that they may change with the development of the brain. However, they are on a similar level for different conception groups supporting our previous statistical analysis that MRI values of ICSI and ET groups are not significantly different from NAT. Conclusions The results showed that there was no significant difference in brain development patterns between different modes of conception, which proved that ART does not affect the development of brain myelin in fetuses and infants.

scholarly journals Short-lasting unilateral neuralgiform headache with autonomic symptoms associated with idiopathic hypertrophic pachymeningitis

2018 ◽  
Vol 1 ◽  
pp. 251581631879054
Author(s):  
J Matthijs Biesbroek ◽  
Dirk R Rutgers ◽  
Sander van Gulik ◽  
Catherina JM Frijns
Keyword(s):  
Brain Mri ◽  
Resonance Imaging ◽  
Hypertrophic Pachymeningitis ◽  
Trigeminal Autonomic Cephalalgia ◽  
Autonomic Symptoms ◽  
Meningeal Inflammation ◽  
Magnetic Resonance Imaging Mri ◽  
Multiple Episodes ◽  
Rule Out

Short-lasting unilateral neuralgiform headache with autonomic symptoms (SUNA) is a rare form of trigeminal autonomic cephalalgia. SUNA is frequently associated with a trigeminal neurovascular conflict and rarely occurs secondary to other intracranial pathology. We report a patient with SUNA that was associated with ipsilateral meningeal inflammation caused by idiopathic hypertrophic pachymeningitis (HP). During the 9-year follow-up, she experienced multiple episodes of SUNA, most of which occurred during exacerbations of the pachymeningitis. This is the third case of SUNA associated with HP reported in the literature. Based on this observation, we suggest that in patients presenting with SUNA, besides dedicated magnetic resonance imaging (MRI) of the trigeminal nerve, gadolinium-enhanced brain MRI should be performed to rule out HP.

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