Improved signal-to-noise ratio in EPI sequences with highly asymmetric spin echo and highly asymmetric STEAM preparations (HASE-EPI and HASTEAM-EPI)

Background: Time Repetition (TR) is one parameter that can affect the value of Signal to Noise Ratio (SNR) and Contrast to Noise Ratio (CNR). The purpose of this research is to know the effect of variation of TR value on SNR and CNR on cervical MRI examination with Sagital T2 Weighted Fast Spin Echo sequence and to know the most optimal TR value from the variation of TR value to SNR and CNR on cervical MRI examination with Sagital T2 Weighted Fast Spin Echo.Methods: The type of this study was experimental study. The study was conducted using MRI 1.5 Tesla at Kasih Ibu Denpasar Hospital. Data were 40 MRI cervical images of sagital Fast Spin Echo from 10 volunteers with four variations of TR (2500 ms, 3000 ms, 3500 ms, and 4000 ms). The SNR and CNR values are measured by identifying the Region of Interest (ROI) in the corpus, discus, cerebro spinal fluid (CSF), and medula spinalis regions to obtain the average signals and compared with the mean deviation of the background. Data was analyzed by regression test to know the influence and by Anova test.Results: The result of the research showed that there was the influence of TR value to SNR and CNR of MRI Cervical Sagital T2 FSE. There was a strong correlation between the variation of TR values with SNR and CNR Cervical with p-value 0.05, the optimal TR value obtained in Cervical Sagital T2 FSE anatomical image on MRI 1,5 Tesla modality was 3500 ms.Conclusion: Time Repetition affected the signal to noise ratio and contrast to noise ratio. TR 3500 ms produced the most optimal cervical MRI image quality.

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Low Flip Angle Gradient Echo Magnetic Resonance Imaging of the Cervical Spine at 0.3 Tesla

Acta Radiologica ◽

10.1177/028418518903000402 ◽

1989 ◽

Vol 30 (4) ◽

pp. 343-348 ◽

Cited By ~ 2

Author(s):

S. Holtås ◽

F. Ståhlberg ◽

H. Nilsson ◽

E.-M. Larsson ◽

A. Ericsson

Keyword(s):

Cervical Spine ◽

Signal To Noise Ratio ◽

Spin Echo ◽

Flip Angle ◽

Acquisition Time ◽

Gradient Echo ◽

Signal To Noise ◽

Spine Imaging ◽

Spin Echo Sequence ◽

Noise Ratio

The influence of flip angle and TR on signal to noise ratio and contrast between cerebrospinal fluid (CSF) and cord was evaluated in cervical spine imaging in 5 volunteers, using gradient echo technique. All experiments were performed on a 0.3 tesla Fonar β-3000 M scanner using solenoidal surface coils. The most useful sequence was considered to be TR/TE=300/12 ms and 10° flip angle. This sequence provided images with a ‘myelographic appearance’ with good delineation of cord, CSF and epidural space. The grey and white matter was also regularly visualized. The acquisition time was considerably shorter than would have been necessary if a long TR/TE spin echo sequence had been used to obtain the same contrast pattern and the sequence was not as sensitive to motion as was the spin echo sequence. The sequence was also evaluated in 10 patients with degenerative disease and in 5 with lesions in the cord. The gradient echo sequence was found to be equal to or better than short and long TR/TE spin echo sequences in demonstrating narrowing of the spinal canal and cord lesions. The drawback is the limited signal to noise ratio.

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Analisis Pembobotan T2 Turbo Spin Echo (TSE) brain MRI Potongan Axial dengan Penggunaan Sensitivity Encoding (SENSE) dan Tanpa Penggunaan Sense : Evaluasi pada Signal to Noise Ratio (SNR) dan Scan Time

Jurnal Imejing Diagnostik (JImeD) ◽

10.31983/jimed.v2i2.3174 ◽

2016 ◽

Vol 2 (2) ◽

pp. 148-153

Author(s):

Fani Susanto ◽

A. Gunawan Santoso ◽

Bagus Abimanyu

Keyword(s):

Signal To Noise Ratio ◽

Spin Echo ◽

Brain Mri ◽

Statistical Test ◽

Turbo Spin Echo ◽

Signal To Noise ◽

Turbo Spin ◽

Sensitivity Encoding ◽

Scan Time ◽

Noise Ratio

Background: On examination brain MRI often finds non-cooperative patients, requiring rapid acquisition techniques. The parallel imaging sensitivity encoding (SENSE) technique utilizes spatial RF coated phased array information to reduce acquisition time by reducing the K space sampling line to produce good quality and spatial resolution, but has a limitation of signal-to-noise ratio (SNR) reduction. SENSE is used with MRI sequence pulses one of them turbo spin echo (TSE). The purpose of this study was to determine the difference of SNR and scan time on TSE T2 weighting brain MRI axial slices between use SENSE and without SENSE.Methods: This research is quantitative study with experimental approach. The data were collected from May to June 2016 at the Radiology Installation of Premier Bintaro Hospital by calculating the SNR through the software for the region of interest (ROI) and calculating the scan time through the scan timer on the workstation monitor. Data analysis was done by statistical test with SPPS 16 application using paired T-test and descriptiveResults: From the result of statistical test, it is known that SNR at TSE T2 weighting between with and without SENSE is obtained p-value 0,000 (p 0, 05). This is because the encoding of the both image are different, On TSE T2 weighting image without SENSE there is the use 1800 pulses approaching the effective TE so the shallow gradient produces maximum echo, while on TSE T2 weighting with SENSE there is a reduction of phase encoding row in K space and the presence of g-factor causes the SNR to decrease. From descriptive analysis result, is known that scan time on TSE T2 weighting between with and without SENSE usage is obtained by reduction of scan time for 1 minute 24 seconds (49, 01%). This is because the acquisition technique between the both image are different, on the TSE T2 weighting without SENSE there is ETL in charging K space, whereas on the TSE T2 Weighting with SENSE there is R-factor causing the sampling not to fill all K space so that scanning time is reduced.Conclusion: There are SNR and scan time differences on TSE T2 weighting brain MRI of the axial slices with SENSE and without SENSE usage.

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Improvement in Signal-to-noise Ratio and Reduction of Chemical Shift and Motion-induced Artifacts by Summation of Gradient and Spin Echo Data Acquisition

Journal of Computer Assisted Tomography ◽

10.1097/00004728-198911000-00017 ◽

1989 ◽

Vol 13 (6) ◽

pp. 1041-1047 ◽

Cited By ~ 3

Author(s):

Simon Vinitski ◽

Donald G. Mitchell ◽

Matthew D. Rifkin ◽

D. Lawrence Burk

Keyword(s):

Chemical Shift ◽

Data Acquisition ◽

Signal To Noise Ratio ◽

Spin Echo ◽

Signal To Noise ◽

Noise Ratio

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Analisis Pengaruh Perubahan Number Scan Average Terhadap Signal to Noise Ratio Pada Citra MRI Brain Sekuen T2 Fast Spin Echo (FSE)

Jurnal Ilmiah Giga ◽

10.47313/jig.v21i1.578 ◽

2019 ◽

Vol 21 (1) ◽

pp. 1

Author(s):

Rakhmat Kurniawan ◽

Puji Hartoyo ◽

Ni Larasati Kartika Sari

Keyword(s):

Signal To Noise Ratio ◽

Spin Echo ◽

Median Filter ◽

Fast Spin Echo ◽

Signal To Noise ◽

Mri Brain ◽

Noise Ratio ◽

Fast Spin

<div style="’text-align: justify;">Telah dilakukan penelitian tentang pengaruh perubahan nilai parameter Number Scan Average (NSA) terhadap kualitas citra MRI yang direpresentasikan oleh nilai Signal to Noise Ratio (SNR). Penelitian dilakukan menggunakan citra otak potongan aksial menggunakan sekuen T2 Fast Spin Echo. Variasi nilai NSA yang digunakan adalah 2, 4 dan 6. Nilai SNR dihitung memanfaatkan algoritma median filter pada software Matlab 2013a. SNR diperoleh dengan membandingkan nilai piksel rata-rata dari citra setelah diberi median filter dengan nilai piksel rata-rata dari selisih citra sebelum dan sesudah diberi median filter. Nilai SNR pada NSA 2,4 dan 6 masing-masing sebesar 81,3411, 85,8796, dan 87,2757. Hal tersebut menunjukkan bahwa semakin besar nilai NSA, semakin besar pula nilai SNR yang diperoleh. Kenaikan NSA dari 2 ke 4, meningkatkan NSA sebesar 5,6%, dan perubahan NSA dari 4 ke 6, meningkatkan SNR sebanyak 1,6%. Namun, kenaikan nilai NSA juga menambah waktu scanning. Kenaikan NSA dari 2 ke 4, dan 4 ke 6, menambah waktu scanning rata-rata sebesar 2 menit.</div>

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