scholarly journals Co-registration Comparison of On-Scalp Magnetoencephalography and Magnetic Resonance Imaging

2021 ◽  
Vol 15 ◽  
Author(s):  
Fuzhi Cao ◽  
Nan An ◽  
Weinan Xu ◽  
Wenli Wang ◽  
Yanfei Yang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Source Localization ◽  
Structured Light ◽  
Laser Scanner ◽  
High Signal ◽  
Resonance Imaging ◽  
Registration Error ◽  
Structured Light Scanner ◽  
Reference Phantom

Magnetoencephalography (MEG) can non-invasively measure the electromagnetic activity of the brain. A new type of MEG, on-scalp MEG, has attracted the attention of researchers recently. Compared to the conventional SQUID-MEG, on-scalp MEG constructed with optically pumped magnetometers is wearable and has a high signal-to-noise ratio. While the co-registration between MEG and magnetic resonance imaging (MRI) significantly influences the source localization accuracy, co-registration error requires assessment, and quantification. Recent studies have evaluated the co-registration error of on-scalp MEG mainly based on the surface fit error or the repeatability error of different measurements, which do not reflect the true co-registration error. In this study, a three-dimensional-printed reference phantom was constructed to provide the ground truth of MEG sensor locations and orientations relative to MRI. The co-registration performances of commonly used three devices—electromagnetic digitization system, structured-light scanner, and laser scanner—were compared and quantified by the indices of final co-registration errors in the reference phantom and human experiments. Furthermore, the influence of the co-registration error on the performance of source localization was analyzed via simulations. The laser scanner had the best co-registration accuracy (rotation error of 0.23° and translation error of 0.76 mm based on the phantom experiment), whereas the structured-light scanner had the best cost performance. The results of this study provide recommendations and precautions for researchers regarding selecting and using an appropriate device for the co-registration of on-scalp MEG and MRI.

scholarly journals Custom, spray coated receive coils for magnetic resonance imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. M. Zamarayeva ◽  
K. Gopalan ◽  
J. R. Corea ◽  
M. Z. Liu ◽  
K. Pang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Silver Nanoparticle ◽  
Material Selection ◽  
Spray Deposition ◽  
Dielectric Materials ◽  
Patient Specific ◽  
High Signal ◽  
Resonance Imaging ◽  
3D Printed

AbstractWe have developed a process for fabricating patient specific Magnetic Resonance Imaging (MRI) Radio-frequency (RF) receive coil arrays using additive manufacturing. Our process involves spray deposition of silver nanoparticle inks and dielectric materials onto 3D printed substrates to form high-quality resonant circuits. In this paper, we describe the material selection and characterization, process optimization, and design and testing of a prototype 4-channel neck array for carotid imaging. We show that sprayed polystyrene can form a low loss dielectric layer in a parallel plate capacitor. We also demonstrate that by using sprayed silver nanoparticle ink as conductive traces, our devices are still dominated by sample noise, rather than material losses. These results are critical for maintaining high Signal-to-Noise-Ratio (SNR) in clinical settings. Finally, our prototype patient specific coil array exhibits higher SNR (5 × in the periphery, 1.4 × in the center) than a commercially available array designed to fit the majority of subjects when tested on our custom neck phantom. 3D printed substrates ensure an optimum fit to complex body parts, improve diagnostic image quality, and enable reproducible placement on subjects.

scholarly journals Hepatic epithelioid hemangioendothelioma: a report from three university centers

2016 ◽  
Vol 49 (5) ◽  
pp. 288-294 ◽  
Author(s):  
Antonello Giardino ◽  
Frank H. Miller ◽  
Bobby Kalb ◽  
Miguel Ramalho ◽  
Diego R. Martin ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Epithelioid Hemangioendothelioma ◽  
Magnetic Resonance Images ◽  
Central Core ◽  
Magnetic Resonance Imaging Examination ◽  
High Signal ◽  
Resonance Imaging ◽  
Peripheral Ring ◽  
Venous Phase

Abstract Objective: To determine common imaging findings of hepatic epithelioid hemangioendothelioma on magnetic resonance images. Materials and Methods: A search was made of three institutional databases between January 2000 and August 2012. Seven patients (mean age, 47 years; range, 21-66 years; 6 women) with pathology-confirmed diagnosis of hepatic epithelioid hemangioendothelioma who had undergone magnetic resonance imaging were identified. None of the patients had received any treatment for hepatic epithelioid hemangioendothelioma at the time of the initial magnetic resonance imaging examination. Results: Hepatic epithelioid hemangioendothelioma tumors appeared as focal masses in 7/7 patients, greater than 5 in number, with a coalescing lesion in 1/5, and peripheral localization in 6/7. Capsular retraction was present in 4/7, and was associated with peripherally located lesions. Early ring enhancement was appreciated in the majority of lesions in 7/7 patients. Centripetal progressive enhancement was shown in 5/7 patients on venous phase that exhibited a distinctive thick inner border of low signal on venous phase images, and a central core of delayed enhancement. Small lesions did not show this. Conclusion: The combination of multifocal round-configuration lesions that are predominantly peripheral and exhibit early peripheral ring enhancement and late appearance of an inner thick border of low signal and central core of high signal may represent an important feature for hepatic epithelioid hemangioendothelioma.

Magnetic resonance imaging of spinal arteriovenous malformations

1987 ◽  
Vol 66 (6) ◽  
pp. 830-834 ◽  
Author(s):  
John L. Doppman ◽  
Giovanni Di Chiro ◽  
Andrew J. Dwyer ◽  
Joseph L. Frank ◽  
Edward H. Oldfield
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Arteriovenous Malformations ◽  
High Signal ◽  
Resonance Imaging ◽  
Content Type ◽  
Spinal Arteriovenous Malformations ◽  
Magnetic Resonance Imaging Mri ◽  
Spinal Avm ◽  
Fine Print

✓ Magnetic resonance imaging (MRI) was performed on 12 patients with spinal arteriovenous malformations (AVM's). Six lesions were intramedullary, five were dural, and one was in a posterior extramedullary location. Serpentine filling defects similar to the classic myelographic findings were demonstrated within the high-signal cerebrospinal fluid on T2-weighted coronal scans. The intramedullary nidus was identified by MRI as an area of low-signal intensity within the cord in all six intramedullary AVM's. Neither the dural nor the posterior extramedullary lesions showed intramedullary components. It is concluded that MRI may noninvasively provide the initial diagnosis of a spinal AVM and distinguish intramedullary from dural and extramedullary lesions.

scholarly journals Visualisation of fetal meconium on post-mortem magnetic resonance imaging scans: a retrospective observational study

2020 ◽  
Vol 9 (11) ◽  
pp. 205846012097054
Author(s):  
Georgia Hyde ◽  
Andrew Fry ◽  
Ashok Raghavan ◽  
Elspeth Whitby
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Signal Intensity ◽  
Interrater Reliability ◽  
Hepatic Flexure ◽  
Radiology Department ◽  
High Signal ◽  
Post Mortem ◽  
Resonance Imaging ◽  
Tertiary Referral Centre

Background Less invasive techniques for fetal post-mortems are increasingly used to correlate with parental wishes. With the use of post-mortem magnetic resonance imaging (MRI), normal appearance of the organs must be established. Purpose To investigate the after death appearance of the fetal meconium throughout gestation using the hyperintense appearance of meconium on T1 weighted MRI. Material and Methods This was a retrospective study that took place in a tertiary referral centre radiology department. Sixty-two fetal body post-mortem MRI scans (January 2014 to May 2018) between 12 and 41 weeks gestation were reviewed. Signal intensity of meconium at the rectum, sigmoid colon, splenic flexure and hepatic flexure was evaluated and correlated with gestational age. Interrater reliability was calculated. Results Meconium did not consistently have high signal intensity on T1 scans and was not always obvious. Rectal meconium had the highest intensity, and the more proximal the bowel the lower the intensity. The meconium had higher intensity at earlier gestations. Interrater reliability for rectal meconium gradings was excellent. Conclusion This study provides the first published primary research on the appearance of fetal meconium on post-mortem MRI. Overall, results were variable and suggest an alteration of bowel contents after death, but further investigation is needed to effectively inform practice.

High signal intensity on magnetic resonance imaging is a better predictor of neurobehavioral performances than blood manganese in asymptomatic welders

2009 ◽  
Vol 30 (4) ◽  
pp. 555-563 ◽  
Author(s):  
Yongmin Chang ◽  
Yangho Kim ◽  
Seung-Tae Woo ◽  
Hui-Jin Song ◽  
Suk Hwan Kim ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Signal Intensity ◽  
High Signal Intensity ◽  
High Signal ◽  
Resonance Imaging ◽  
Blood Manganese

scholarly journals Differentiation between Pure Mucinous Breast Carcinomas and Fibroadenomas with Strong High-Signal Intensity on T2-Weighted Images from Dynamic Contrast-Enhanced Magnetic Resonance Imaging

Breast Care ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 32-37
Author(s):  
Ning Qu ◽  
Yahong Luo ◽  
Tao Yu ◽  
Huihui Yu
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Signal Intensity ◽  
High Signal ◽  
Breast Carcinomas ◽  
Resonance Imaging ◽  
Enhancement Pattern ◽  
Dce Mri ◽  
Dynamic Contrast Enhanced ◽  
Contrast Enhanced

Objective: This study aimed to identify characteristics that can differentiate between pure mucinous breast carcinomas (PMBCs) and fibroadenomas (FAs) with strong high-signal intensity on T2-weighted images (T2-SHi) from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Methods: The DCE-MRI tumor characteristics were compared and analyzed between 35 PMBCs and 70 FAs with T2-SHi. Results: Multivariate analysis revealed that delayed enhancement pattern was the only significant independent predictor (p = 0.007). Conclusion: A delayed enhancement pattern is the most reliable characteristic for differentiating PMBCs from FAs with T2-SHi from DCE-MRI.

Analysis on the Diagnosis of Ovarian Follicular Membrane Cell Tumor by Magnetic Resonance Imaging Under Statistical Discrepancy Algorithm

2021 ◽  
Vol 11 (2) ◽  
pp. 612-617
Author(s):  
Yirong Zhao ◽  
Cuifang Liu ◽  
Xiaoyu Zhang ◽  
Henglian Liu ◽  
Lingfeng Zou ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Cell Tumor ◽  
High Signal ◽  
Lesion Site ◽  
Resonance Imaging ◽  
Image Characteristics ◽  
Unilateral Disease ◽  
Diagnosis Rate ◽  
Membrane Cell

In order to improve the early diagnosis rate of follicular cell tumor (C-Tu), reduce the occurrence of malignant tumor, make the patients receive timely treatment, and reduce the mortality, in this research, a total of 48 patients diagnosed as follicular C-Tu admitted to Chongqing Traditional Chinese Medicine Hospital from January 2017 to December 2018 were selected. Computed tomography (CT) and functional magnetic resonance imaging (MRI) images were used to obtain the image of lesion site and analyze the image characteristics. Patients were grouped and compared according to the difference of image characteristics based on statistical discrepancy algorithm (SDA). The specificity (Sp) and sensitivity (Se) of CT scan and MRI images were compared and analyzed to provide the most effective detection method for the subsequent clinical diagnosis. The results showed that most patients had unilateral disease, and most of them were round or oval, with different sizes. The SDA can effectively organize and analyze the influence characteristics of patients. Patients can be grouped according to the proportion of cystic firmness shown in the image. MRI plain scan showed moderate or low signal on T1WI and high signal on T2WI. The T2WI signal could be enhanced with the continuous cystic change of lesion site. The diagnosis efficiency (DE) of CT and MRI was compared with that of surgical pathology as the gold standard. The Se and accuracy (Ac) of MRI diagnosis were higher than that of CT diagnosis, and the comparison of kappa consistency was 0.73 (P < 0.05), which showed that the imaging diagnosis of follicular membrane cell tumour by MRI could obtain higher diagnosis Ac.

Sign in / Sign up

Export Citation Format

Share Document