Technical Aspects on Magnetic Resonance Imaging of the Spine at 1.5 Tesla

1987 ◽  
Vol 28 (4) ◽  
pp. 375-381 ◽  
Author(s):  
S. L. Holtås ◽  
D. B. Plewes ◽  
J. H. Simon ◽  
S. Ekholm ◽  
D. K. Kido ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Image Quality ◽  
Surface Coil ◽  
Motion Artifacts ◽  
The Body ◽  
Acquisition Time ◽  
Slice Thickness ◽  
Resonance Imaging ◽  
Technical Aspects

Technical aspects on surface coil magnetic resonance imaging of the spine using a superconducting system with a field strength of 1.5 tesla are described. By using a flat surface coil instead of the body coil the image quality was markedly improved and the signal-to-noise ratio (S/N) was increased approximately 2.6 times. Small voxels resulted in low S/N. The best image quality was achieved with a slice thickness of 5 mm, a field of view of 20 to 24 cm and a matrix of 256×256. Interleaved slices provided superior image quality compared with contiguous slices at the expense of acquisition time. For sagittal images the phase encoding gradient should be in the cranio-caudal direction to minimize motion artifacts. To obtain T1 and T2 images of high quality, spin echo pulse sequences with TR 600/TE 20 ms and TR 2000/TE 40 to 80 ms are useful.

scholarly journals A preliminary study of synthetic magnetic resonance imaging in rectal cancer: imaging quality and preoperative assessment

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Li Zhao ◽  
Meng Liang ◽  
Pu-yeh Wu ◽  
Yang Yang ◽  
Hongmei Zhang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Rectal Cancer ◽  
Magnetic Resonance ◽  
Image Quality ◽  
Motion Artifacts ◽  
Nodal Staging ◽  
Resonance Imaging ◽  
T Stage ◽  
Lesion Conspicuity ◽  
Synthetic Mri

Abstract Purpose To compare the imaging quality, T stage and extramural venous invasion (EMVI) evaluation between the conventional and synthetic T2-weighted imaging (T2WI), and to investigate the role of quantitative values obtained from synthetic magnetic resonance imaging (MRI) for assessing nodal staging in rectal cancer (RC). Methods Ninety-four patients with pathologically proven RC who underwent rectal MRI examinations including synthetic MRI were retrospectively recruited. The image quality of conventional and synthetic T2WI was compared regarding signal-to-noise ratio (SNR), contrast-to-noise (CNR), sharpness of the lesion edge, lesion conspicuity, absence of motion artifacts, and overall image quality. The accuracy of T stage and EMVI evaluation on conventional and synthetic T2WI were compared using the Mc-Nemar test. The quantitative T1, T2, and PD values were used to predict the nodal staging of MRI-evaluated node-negative RC. Results There were no statistically significant differences between conventional and synthetic T2WI in SNR, CNR, overall image quality, lesion conspicuity, and absence of motion artifacts (p = 0.058–0.978). There were no significant differences in the diagnostic accuracy of T stage and EMVI between conventional and synthetic T2WI from two observers (p = 0.375 and 0.625 for T stage; p = 0.625 and 0.219 for EMVI). The T2 value showed good diagnostic performance for predicting the nodal staging of RC with the area under the receiver operating characteristic, sensitivity, specificity, and accuracy of 0.854, 90.0%, 71.4%, and 80.3%, respectively. Conclusions Synthetic MRI may facilitate preoperative staging and EMVI evaluation of RC by providing synthetic T2WI and quantitative maps in one acquisition.

Surface-Coil Magnetic Resonance Imaging of the Internal Auditory Canal and the Inner Ear Preliminary Report

1995 ◽  
Vol 104 (10) ◽  
pp. 776-782 ◽  
Author(s):  
Iwao Honjo ◽  
Eri Naito ◽  
Yasushi Natto ◽  
Haruo Takahashi ◽  
Kazumasa Nishimura ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Inner Ear ◽  
Internal Auditory Canal ◽  
Surface Coil ◽  
Cochlear Nerve ◽  
Acquisition Time ◽  
Computer Assisted ◽  
Resonance Imaging ◽  
Eighth Nerve

Parasagittal surface-coil magnetic resonance imaging of the internal auditory canal and the inner ear was performed. We used T2-weighted fast spin-echo sequences to visualize the inner ear and the individual nerves in the internal auditory canal with high contrast in a short acquisition time. Computer-assisted quantitative measurement of the nerves was performed to estimate the cross-sectional areas and the diameters of the nerves. The average diameters of the facial nerve, the cochlear nerve, and the vestibular nerve of normal-hearing individuals were, respectively, 1.1 ± 0.2 mm (mean ± SD), 1.2 ± 0.2 mm, and 1.5 ± 0.2 mm. In the cerebellopontine angle, the average diameter of the eighth nerve was 1.8 ± 0.2 mm. Two patients with unilateral and bilateral hearing loss were also presented. In the patient with unilateral deafness, the cochlear nerve of the diseased side was not identified and the eighth cranial nerve diameter was smaller than that of the normal side. In the patient with bilateral deafness, fibrosis of the inner ear and atrophy of the eighth nerve were demonstrated in the ear with posttraumatic deafness. The present method may represent a new approach to the assessment of pathologic processes involving the inner ear and the nerves in the internal auditory canal.

scholarly journals Surface coil intensity correction in magnetic resonance imaging in spinal metastases

Open Medicine ◽  
2017 ◽  
Vol 12 (1) ◽  
pp. 138-143 ◽  
Author(s):  
Hong Ren ◽  
Wei Lin ◽  
Xianjun Ding
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Image Quality ◽  
Signal Intensity ◽  
Reading Time ◽  
Phased Array ◽  
Spinal Metastases ◽  
Surface Coil ◽  
Resonance Imaging ◽  
T1 And T2

AbstractObjectiveTo evaluate the clinical application of phased-array surface coil intensity correction in magnetic resonance imaging (MRI) in spinal metastases.Methods3 phantoms and 50 patients with a corresponding total number of 80 spinal metastases were included in this study. Fast spin echo T1- and T2- weighted MRI with and without surface coil intensity correction was routinely performed for all phantoms and patients. Phantoms were evaluated by means of variance to mean ratio of signal intensity on both T1- and T2- weighted MRI obtained with and without surface coil intensity correction. Spinal metastases were evaluated by image quality scores; reading time per case on both T1- and T2- weighted MRI obtained with and without surface coil intensity correction.ResultsSpinal metastases were diagnosed more successfully on MRI with surface coil intensity correction than on MRI with conventional surface coil technique. The variance to mean ratio of signal intensity was 53.36% for original T1-weighted MRI and 53.58% for original T2-weighted MRI. The variance to mean ratio of signal intensity was reduced to 18.99% for T1-weighted MRI with surface coil intensity correction and 22.77% for T2-weighted MRI with surface coil intensity correction. The overall image quality scores (interface conspicuity of lesion and details of lesion) were significantly higher than those of the original MRI. The reading time per case was shorter for MRI with surface coil intensity correction than for MRI without surface coil intensity correction.ConclusionsPhased-array surface coil intensity correction in MRIs of spinal metastases provides improvements in image quality that leads to more successfully detection and assessment of spinal metastases than original MRI.

Systematic Analysis and Review of Magnetic Resonance Imaging (MRI) Reconstruction Techniques

2021 ◽  
Vol 16 ◽  
Author(s):  
Penta Anil Kumar ◽  
R. Gunasundari ◽  
R. Aarthi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Optimization Technique ◽  
Motion Artifacts ◽  
Reconstruction Technique ◽  
Resonance Imaging ◽  
Research Gaps ◽  
Conventional Mri ◽  
Mri Reconstruction ◽  
Magnetic Resonance Imaging Mri

Background: Magnetic Resonance Imaging (MRI) plays an important role in the field of medical diagnostic imaging as it poses non-invasive acquisition and high soft-tissue contrast. However, the huge time is needed for the MRI scanning process that results in motion artifacts, degrades image quality, misinterpretation of data, and may cause uncomfortable to the patient. Thus, the main goal of MRI research is to accelerate data acquisition processing without affecting the quality of the image. Introduction: This paper presents a survey based on distinct conventional MRI reconstruction methodologies. In addition, a novel MRI reconstruction strategy is proposed based on weighted Compressive Sensing (CS), Penalty-aided minimization function, and Meta-heuristic optimization technique. Methods: An illustrative analysis is done concerning adapted methods, datasets used, execution tools, performance measures, and values of evaluation metrics. Moreover, the issues of existing methods and the research gaps considering conventional MRI reconstruction schemes are elaborated to obtain improved contribution for devising significant MRI reconstruction techniques. Results: The proposed method will reduce conventional aliasing artifacts problems, may attain lower Mean Square Error (MSE), higher Peak Signal-to-Noise Ratio (PSNR), and Structural SIMilarity (SSIM) index. Conclusion: The issues of existing methods and the research gaps considering conventional MRI reconstruction schemes are elaborated to devising an improved significant MRI reconstruction technique.

Magnetic Resonance Imaging in the Diagnosis of Disruption of the Posterior Tibial Tendon

Foot & Ankle ◽  
1987 ◽  
Vol 8 (3) ◽  
pp. 144-147 ◽  
Author(s):  
Ian J. Alexander ◽  
Kenneth A. Johnson ◽  
Thomas H. Berquist
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Soft Tissues ◽  
Diagnostic Technique ◽  
Clinical Findings ◽  
The Body ◽  
Posterior Tibial Tendon ◽  
Resonance Imaging ◽  
Posterior Tibial ◽  
Magnetic Resonance Imaging Mri

Magnetic resonance imaging (MRI), a useful technique of studying soft tissues of the body, can be very effective in assessing the integrity of tendons. Usually a patient with a complete tear of the posterior tibial tendon has characteristic physical findings. In the patient presented, MRI demonstrated a complete disruption of the posterior tibial tendon, despite the absence of the commonly associated clinical findings. In view of the difficulties encountered with attempted tenography of the completely torn posterior tibial tendon, MRI provides a sensitive alternative diagnostic technique.

Magnetic Resonance Imaging of Spinal Cord Disease of Childhood

PEDIATRICS ◽  
1986 ◽  
Vol 78 (2) ◽  
pp. 251-256
Author(s):  
Roger J. Packer ◽  
Robert A. Zimmerman ◽  
Leslie N. Sutton ◽  
Larissa T. Bilaniuk ◽  
Derek A. Bruce ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Spinal Cord ◽  
Magnetic Resonance ◽  
Vertebral Body ◽  
Congenital Anomalies ◽  
Correct Diagnosis ◽  
Surface Coil ◽  
Resonance Imaging ◽  
Spinal Cord Disease ◽  
Magnetic Resonance Imaging Mri

Correct diagnosis of spinal cord disease in childhood is often delayed, resulting in irreversible neurologic deficits. A major reason for this delay is the lack of a reliable means to noninvasively visualize the spinal cord. Magnetic resonance imaging (MRI) should be useful in the evaluation of diseases of the spinal cord. A 1.5 Tesla MRI unit with a surface coil was used to study 41 children, including eight patients with intrinsic spinal cord lesions, eight patients with masses compressing the cord, 12 patients with congenital anomalies of the cord or surrounding bony structures, three patients with syrinxes, and three patients with vertebral body abnormalities. Intrinsic lesions of the cord were well seen in all cases as intrinsic irregularly widened, abnormally intense cord regions. MRI was helpful in following the course of disease in patients with primary spinal cord tumors. Areas of tumor were separable from syrinx cavities. Extrinsic lesions compressing the cord and vertebral body disease were also well visualized. Congenital anomalies of the spinal cord, including tethering and lipomatous tissue, were better seen on MRI than by any other radiographic technique. MRI is an excellent noninvasive "screening" technique for children with suspected spinal cord disease and may be the only study needed in many patients with congenital spinal cord anomalies. It is also an excellent means to diagnose and follow patients with other forms of intra- and extraspinal pathology.

Sign in / Sign up

Export Citation Format

Share Document