Wireless amplified NMR detector for improved visibility of image contrast in heterogeneous lesions

Zeng, Xian‐Chun; Xu, Shengqiang; Cao, Changyong; Wang, Jian; Cui, Qian

doi:10.1002/nbm.3963

Cited by 6 publications

(4 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Initially, the WD was used as an implantable detector mounted on the surface of the kidney (8). Subsequently, to image heterogeneous tumors or aorta walls more clearly, the WD was reengineered with cylindrical symmetry for nonsurgical use inside the digestive tract (9)(10)(11)(12). In this study, a disc-shaped WD, which is more suitable for body superficial tissue or organ examination, was used to overcome the sensitivity limitation of conventional MRI in TMJ condylar imaging.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of condylar osseous changes using a wireless detector with proton density–weighted imaging sequences

Ming¹,

Cheng²,

Tian³

et al. 2023

Quant Imaging Med Surg

View full text Add to dashboard Cite

Background: Cone-beam computed tomography (CBCT) is the gold standard for evaluating condylar osseous changes. However, the radiation risk and low soft-tissue resolution of CBCT make it unsuitable for evaluating soft tissue such as the articular disc and lateral pterygoid muscle. This study aimed to qualitatively and quantitatively evaluate the feasibility and advantages of using wireless detectors (WD) with proton density-weighted imaging (PDWI) sequences to image condyle changes in patients with temporomandibular disorders (TMD).Methods: This study involved 20 patients (male =8, female =12; mean age 31.65 years, SD 12.68 years) with TMD. All participants underwent a closed oblique sagittal PDWI scan with head/neck coupling coiling (HNCC) and wireless detector-HNCC (WD-HNCC) on a 3.0 T magnetic resonance imaging (MRI) scanner. Subsequently, the changes in the condyle bones in the scanned images for the 2 image types were scored subjectively and compared qualitatively. The contrast-to-noise ratio (CNR) of the 2 types of scanned images was compared quantitatively. The comparison of CNR differences between the 2 types of images was performed using the paired t-test. The kappa statistic was used to test the consistency of quantitative analyses of MRI images between observers. The subjective scores of condylar osseous changes in the 2 types of images were compared by paired rank-sum test. A P value <0.05 was considered statistically significant.Results: A total of 40 condyles from 20 patients were scanned. Among them, 8 condyles showed no bone changes, and the other 32 condyles demonstrated condylar osseous changes of varying degrees and nature. These 32 condyles were used in the subsequent analysis. As compared to images acquired by HNCC in the PDWI sequence, the WD-HNCC images more clearly showed mandibular osteophyte, bone cortical erosion, subcortical cystic focus, and bone cortical hyperplasia and thickening. In addition, the WD-HNCC was demonstrated to improve image CNR by 158.9% compared to HNCC (28.17±16.01 vs. 10.88±6.53; t=8.63; P=0.001).Conclusions: WD-HNCC in PDWI sequences is suitable for imaging the condylar bone changes of patients with TMD and significantly improves the image quality.

show abstract

Section: Introductionmentioning

confidence: 99%

Evaluation of condylar osseous changes using a wireless detector with proton density–weighted imaging sequences

Ming¹,

Cheng²,

Tian³

et al. 2023

Quant Imaging Med Surg

View full text Add to dashboard Cite

show abstract

“…Although, there has been significant progress in improving the MRI sensitivity detection by increasing the field strengths [2], working with RF coil arrays [3], and parallel imaging acquisition [4]- [8], these techniques still have their own limitations to obtain sufficient signal sensitivity, especially in target regions that are deep inside the body. Recently, a complementary method is demonstrated to improve the detection sensitivity of the deep lying tissues using a Wireless Amplified Nuclear Magnetic Resonance (NMR) Detector (WAND) [9]- [12]. In this approach, weak MR signals, which are emitted from deep lying Regions-of-Interest (ROIs), could be sensitively detected by the use of a localized WAND with an integrated amplifier.…”

Section: Introductionmentioning

confidence: 99%

“…WANDs [9]- [11] are initially developed as implantable detectors to observe individual nephrons in vivo, but with sub-optimal homogeneity. Subsequently, they are redesigned with cylindrical symmetry [12], [25], [26] to get a panoramic view of their surrounding areas. Yet, all these detector designs are restricted by their limited diameters to effectively observe wider surrounding regions.…”

Section: Introductionmentioning

confidence: 99%

A Novel Expandable Catheter Wireless Amplified NMR Detector for MR Sensitivity Accessing the Kidney in Rodent Model

Timilsina

Cui

2019

IEEE Trans. Biomed. Circuits Syst.

Self Cite

View full text Add to dashboard Cite

This article demonstrates the enlarged effective range for MRI sensitivity enhancement with a deformable catheter MRI coils integrated with a wirelessly powered amplifier. The expandable balloon Wireless Amplified Nuclear magnetic resonance Detector (WAND) is constructed on a copper-clad polyimide film to resonate at the first and second harmonics of the proton Larmor frequency at 7 Tesla. The WAND is then mounted on a balloon catheter system for easy delivery inside confined orifice. Upon reaching the region of interest, it is unfolded out of the sheath tube to increase its effective size. Magnetic Resonance (MR) imaging experiments with and without the WAND are performed both in a water phantom and in a live rat to evaluate the WAND's sensitivity advantage. Expanded from a 3 mm diameter in its folded state, this deformable WAND can change its width by > 100% in its inflated state to at least 6 mm, leading to a sensitive detection region extending to up to 20 mm in the transverse direction. When the deformable WAND is placed in an artery in the region of the kidney of a live rat, it could achieve at least a 10-fold SNR gain over images acquired by a standard external detector of 22 mm diameter, even though the region of interest is separated from the WAND's surface by a distance larger than the WAND's own width. The proposed expandable catheter WAND could significantly enlarge the effective range for MR sensitivity enhancement in-vivo, enabling versatile applications in interventional MRI.

show abstract

“…Previous designs of WANDs are mostly double frequency resonators [17]- [19] with cylindrical symmetry that used the high frequency resonance mode to receive the pumping signal and the low frequency resonance mode to receive the MR input-signal. As required for efficient parametric signal amplification, the pumping frequency denoted as ω 3 had to be approximately twice the MR detection frequency ω 1 , i.e., ~ 2ω 1 , which required a small ratio (~2.8) between length and diameter, restricting the achievable longitudinal field-ofview (FOV).…”

Section: Introductionmentioning

confidence: 99%

Signal Sensitivity Enhancement of High-Spatial-Resolution MR Imaging With a Concatenated Cylindrical Parametric RF-Resonator

2019

Self Cite

View full text Add to dashboard Cite

Phased array MRI coils can increase sensitivity of superficial tissues owing to their proximity to the detection region. Deep-lying tissues, on the other hand, do not benefit to the same degree. Here we investigate the use of a localized cylindrically symmetric quadruple frequency resonator concatenated with a double frequency resonator to increase the longitudinal field-of-view (FOV) without compromising the spatial-resolution and detection sensitivity. These concatenated array coils work on the principle of a parametric amplification to provide wireless amplification of the locally detected NMR signal prior to inductively coupling the coil to an external pick-up loop with connection to the system receiver. When both the detectors are activated together, the effective range of both overlay to create a larger FOV enabling better identification of detectable regions. Furthermore, the in-vivo test of the concatenated detector provides a worst-case 5-fold SNR gain in regions separated from the cylindrical surface larger than its own diameter. This proposed approach of concatenated detector realization can be individually activated and manipulated to enlarge the sensitivity-enhanced region without sacrificing their individual performance. Compared to double frequency detectors, quadruple frequency detectors offer more flexibility in the choice of detector dimension, enabling multi-element concatenation over an extended FOV.

show abstract

Wireless amplified NMR detector for improved visibility of image contrast in heterogeneous lesions

Cited by 6 publications

References 35 publications

Evaluation of condylar osseous changes using a wireless detector with proton density–weighted imaging sequences

Evaluation of condylar osseous changes using a wireless detector with proton density–weighted imaging sequences

A Novel Expandable Catheter Wireless Amplified NMR Detector for MR Sensitivity Accessing the Kidney in Rodent Model

Signal Sensitivity Enhancement of High-Spatial-Resolution MR Imaging With a Concatenated Cylindrical Parametric RF-Resonator

Contact Info

Product

Resources

About