scholarly journals Feasibility study of using simultaneous multi-slice RESOLVE diffusion weighted imaging to assess parotid gland tumors: comparison with conventional RESOLVE diffusion weighted imaging

2020 ◽  
Author(s):  
Jia-Suo Jiang ◽  
Liu-Ning Zhu ◽  
Qian Wu ◽  
Yi Sun ◽  
Wei Liu ◽  
...  
Keyword(s):  
Image Quality ◽  
Parotid Gland ◽  
Diffusion Weighted Imaging ◽  
Signal To Noise Ratio ◽  
Anatomical Structure ◽  
Parotid Gland Tumors ◽  
Diffusion Weighted ◽  
Scan Time ◽  
Significant Difference ◽  
Noise Ratio

Abstract Background To evaluate the feasibility of using simultaneous multi-slice (SMS) readout segmentation of long variable echo-trains (RESOLVE) diffusion-weighted imaging (DWI) to assess parotid gland tumors, compared with conventional RESOLVE DWI Methods From September 2018 to December 2018, 20 consecutive patients with parotid tumors who underwent MRI scan for pre-surgery evaluation were enrolled. SMS-RESOLVE DWI and conventional RESOLVE DWI were scanned with matched imaging parameters, respectively. The scan time of two DWI sequences was recorded. Qualitative (anatomical structure differentiation, lesion display, artifact, and overall image quality) and quantitative (apparent diffusion coefficient, ADC; ratio of signal-to-noise ratio, SNR ratio; ratio of contrast-to-noise ratio, CNR ratio) assessments of image quality were performed, and compared between SMS-RESOLVE DWI and conventional RESOLVE DWI. Paired t-test was used for statistical analyses. Results The scan time was 3 minutes and 41 seconds for SMS-RESOLVE DWI, and 5 minutes and 46 seconds for conventional RESOLVE DWI. SMS-RESOLVE DWI produced similar qualitative image quality with RESOLVE DWI (anatomical structure differentiation, P = 0.164; lesion display, P = 0.193; artifact, P = 0.330; overall image quality, P = 0.083). Meanwhile, there were no significant difference on ADCLesion (P = 0.298), ADCMasseter (P = 0.122), SNR ratio (P = 0.584) and CNR ratio (P = 0.217) between two DWI sequences. Conclusion Compared with conventional RESOLVE DWI, SMS-RESOLVE DWI could provide comparable image quality using markedly reduced scan time. SMS could increase the clinical usability of RESOLVE technique for DWI of parotid gland.

scholarly journals Feasibility study of using simultaneous multi-slice RESOLVE diffusion weighted imaging to assess parotid gland tumors: comparison with conventional RESOLVE diffusion weighted imaging

2020 ◽  
Author(s):  
Jia-Suo Jiang ◽  
Liu-Ning Zhu ◽  
Qian Wu ◽  
Yi Sun ◽  
Wei Liu ◽  
...  
Keyword(s):  
Image Quality ◽  
Parotid Gland ◽  
Diffusion Weighted Imaging ◽  
Signal To Noise Ratio ◽  
Anatomical Structure ◽  
Parotid Gland Tumors ◽  
Diffusion Weighted ◽  
Scan Time ◽  
Significant Difference ◽  
Noise Ratio

Abstract Background To evaluate the feasibility of using simultaneous multi-slice (SMS) readout segmentation of long variable echo-trains (RESOLVE) diffusion-weighted imaging (DWI) to assess parotid gland tumors, compared with conventional RESOLVE DWIMethods From September 2018 to December 2018, 20 consecutive patients with parotid tumors who underwent MRI scan for pre-surgery evaluation were enrolled. SMS-RESOLVE DWI and conventional RESOLVE DWI were scanned with matched imaging parameters, respectively. The scan time of two DWI sequences was recorded. Qualitative (anatomical structure differentiation, lesion display, artifact, and overall image quality) and quantitative (apparent diffusion coefficient, ADC; ratio of signal-to-noise ratio, SNR ratio; ratio of contrast-to-noise ratio, CNR ratio) assessments of image quality were performed, and compared between SMS-RESOLVE DWI and conventional RESOLVE DWI by using Paired t-test. Two-sided P value less than 0.05 indicated significant difference.[l1] Results The scan time was 3 minutes and 41 seconds for SMS-RESOLVE DWI, and 5 minutes and 46 seconds for conventional RESOLVE DWI. SMS-RESOLVE DWI produced similar qualitative image quality with RESOLVE DWI (anatomical structure differentiation, P=0.164; lesion display, P=0.193; artifact, P=0.330; overall image quality, P=0.083). Meanwhile, there were no significant difference on ADCLesion (P=0.298), ADCMasseter (P=0.122), SNR ratio (P=0.584) and CNR ratio (P=0.217) between two DWI sequences. Conclusion Compared with conventional RESOLVE DWI, SMS-RESOLVE DWI could provide comparable image quality using markedly reduced scan time. SMS could increase the clinical usability of RESOLVE technique for DWI of parotid gland.

Minimizing table time in patients with claustrophobia using focused ferumoxytol-enhanced MR angiography (f-FEMRA): a feasibility study

2021 ◽  
Vol 94 (1125) ◽  
pp. 20210430
Author(s):  
Puja Shahrouki ◽  
Kim-Lien Nguyen ◽  
John M. Moriarty ◽  
Adam N. Plotnik ◽  
Takegawa Yoshida ◽  
...  
Keyword(s):  
Image Quality ◽  
Mr Angiography ◽  
Signal To Noise Ratio ◽  
Diagnostic Image Quality ◽  
Diagnostic Confidence ◽  
Motion Artefact ◽  
Scan Time ◽  
Wilcoxon Rank Sum Test ◽  
Significant Difference ◽  
Noise Ratio

Objectives: To assess the feasibility of a rapid, focused ferumoxytol-enhanced MR angiography (f-FEMRA) protocol in patients with claustrophobia. Methods: In this retrospective study, 13 patients with claustrophobia expressed reluctance to undergo conventional MR angiography, but agreed to a trial of up to 10 min in the scanner bore and underwent f-FEMRA. Thirteen matched control patients who underwent gadolinium-enhanced MR angiography (GEMRA) were identified for comparison of diagnostic image quality. For f-FEMRA, the time from localizer image acquisition to completion of the angiographic acquisition was measured. Two radiologists independently scored images on both f-FEMRA and GEMRA for arterial and venous image quality, motion artefact and diagnostic confidence using a 5-point scale, five being best. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in the aorta and IVC were measured. The Wilcoxon rank-sum test, one-way ANOVA with Tukey correction and two-tailed t tests were utilized for statistical analyses. Results: All scans were diagnostic and assessed with high confidence (scores ≥ 4). Average scan time for f-FEMRA was 6.27 min (range 3.56 to 10.12 min), with no significant difference between f-FEMRA and GEMRA in diagnostic confidence (4.86 ± 0.24 vs 4.69 ± 0.25, p = 0.13), arterial image quality (4.62 ± 0.57 vs 4.65 ± 0.49, p = 0.78) and motion artefact score (4.58 ± 0.49 vs 4.58 ± 0.28, p > 0.99). f-FEMRA scored significantly better for venous image quality than GEMRA (4.62 ± 0.42 vs 4.19 ± 0.56, p = 0.04). CNR in the IVC was significantly higher for steady-state f-FEMRA than GEMRA regardless of the enhancement phase (p < 0.05). Conclusions: Comprehensive vascular MR imaging of the thorax, abdomen and pelvis can be completed in as little as 5 min within the magnet bore using f-FEMRA, facilitating acceptance by patients with claustrophobia and streamlining workflow. Advances in knowledge: A focused approach to vascular imaging with ferumoxytol can be performed in patients with claustrophobia, limiting time in the magnet bore to 10 min or less, while acquiring fully diagnostic images of the thorax, abdomen and pelvis.

Clinical impact of ultra-high b-value (3000 s/mm2) diffusion-weighted magnetic resonance imaging in prostate cancer at 3T: comparison with b-value of 2000 s/mm2

2021 ◽  
pp. 20210465
Author(s):  
Tsutomu Tamada ◽  
Ayumu Kido ◽  
Yu Ueda ◽  
Mitsuru Takeuchi ◽  
Takeshi Fukunaga ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Diagnostic Performance ◽  
Signal To Noise Ratio ◽  
B Value ◽  
Single Shot ◽  
Signal To Noise ◽  
High B Value ◽  
Diffusion Weighted ◽  
Significant Difference ◽  
Noise Ratio

Objective: High b-value diffusion-weighted imaging (hDWI) with a b-value of 2000 s/mm2 provides insufficient image contrast between benign and malignant tissues and an overlap of apparent diffusion coefficient (ADC) between Gleason grades (GG) in prostate cancer (PC). We compared image quality, PC detectability, and discrimination ability for PC aggressiveness between ultra-high b-value DWI (uhDWI) of 3000 s/mm2 and hDWI. Methods: The subjects were 49 patients with PC who underwent 3T multiparametric MRI. Single-shot echo-planar DWI was acquired with b-values of 0, 2000, and 3000 s/mm2. Anatomical distortion of prostate (AD), signal intensity of benign prostate (PSI), and lesion conspicuity score (LCS) were assessed using a 4-point scale; and signal-to-noise ratio, contrast-to-noise ratio, and mean ADC (×10–3 mm2/s) of lesion (lADC) and surrounding benign region (bADC) were measured. Results: PSI was significantly lower in uhDWI than in hDWI (p < 0.001). AD, LCS, signal-to-noise ratio, and contrast-to-noise ratio were comparable between uhDWI and hDWI (all p > 0.05). In contrast, lADC was significantly lower than bADC in both uhDWI and hDWI (both p < 0.001). In comparison of lADC between tumors of ≤GG2 and those of ≥GG3, both uhDWI and hDWI showed significant difference (p = 0.007 and p = 0.021, respectively). AUC for separating tumors of ≤GG2 from those of ≥GG3 was 0.731 in hDWI and 0.699 in uhDWI (p = 0.161). Conclusion: uhDWI suppressed background signal better than hDWI, but did not contribute to increased diagnostic performance in PC. Advances in knowledge: Compared with hDWI, uhDWI could not contribute to increased diagnostic performance in PC.

The Influence of Alteration of kVp and mAs towards the Image Quality of Acrylic Using CBCT

2019 ◽  
Vol 829 ◽  
pp. 252-257
Author(s):  
Azhari ◽  
Yohanes Hutasoit ◽  
Freddy Haryanto
Keyword(s):  
Image Quality ◽  
Signal To Noise Ratio ◽  
Region Of Interest ◽  
Signal To Noise ◽  
Bite Block ◽  
Significant Difference ◽  
Noise Ratio ◽  
Post Hoc ◽  
Radiograph Image

CBCT is a modernized technology in producing radiograph image on dentistry. The image quality excellence is very important for clinicians to interpret the image, so the result of diagnosis produced becoming more accurate, appropriate, thus minimizing the working time. This research was aimed to assess the image quality using the blank acrylic phantom polymethylmethacrylate (PMMA) (C­5H8O2)n in the density of 1.185 g/cm3 for evaluating the homogeneity and uniformity of the image produced. Acrylic phantom was supported with a tripod and laid down on the chin rest of the CBCT device, then the phantom was fixed, and the edge of the phantom was touched by the bite block. Furthermore, the exposure of the X-ray was executed toward the acrylic phantom with various kVp and mAs, from 80 until 90, with the range of 5 kV and the variation of mA was 3, 5, and 7 mA respectively. The time exposure was kept constant for 25 seconds. The samples were taken from CBCT acrylic images, then as much as 5 ROIs (Region of Interest) was chosen to be analyzed. The ROIs determination was analyzed by using the ImageJ® software for recognizing the influence of kVp and mAs towards the image uniformity, noise and SNR. The lowest kVp and mAs had the result of uniformity value, homogeneity and signal to noise ratio of 11.22; 40.35; and 5.96 respectively. Meanwhile, the highest kVp and mAs had uniformity value, homogeneity and signal to noise ratio of 16.96; 26.20; and 5.95 respectively. There were significant differences between the image uniformity and homogeneity on the lowest kVp and mAs compared to the highest kVp and mAs, as analyzed with the ANOVA statistics analysis continued with the t-student post-hoc test with α = 0.05. However, there was no significant difference in SNR as analyzed with the ANOVA statistic analysis. The usage of the higher kVp and mAs caused the improvement of the image homogeneity and uniformity compared to the lower kVp and mAs.

scholarly journals Pelvis imaging: Achieving dose reduction with different patient positions

2019 ◽  
Vol 34 (4) ◽  
pp. 375-383
Author(s):  
Anja Resnik ◽  
Janez Zibert ◽  
Nejc Mekis
Keyword(s):  
Image Quality ◽  
Effective Dose ◽  
Signal To Noise Ratio ◽  
Absorbed Dose ◽  
Field Size ◽  
Optimal Position ◽  
Dose Area Product ◽  
Significant Difference ◽  
Noise Ratio ◽  
Area Product

The purpose of this research was to determine how dose area product, effective dose, absorbed doses to specific organs, and image quality changed according to different automatic exposure control positions in pelvis imaging. The research was carried out in two parts. The study was conducted on an anthropomorphic phantom and 200 patients referred to pelvic imaging. We measured the dose area product, field size, height, and mass. Then we calculated the effective dose and absorbed dose for individual organs accordingly. Lateral ionizing cells were first positioned in line with the iliac crests (head towards position) and subsequently, with the femoral neck (head away position). All the images were independently evaluated by three radiologists using ViewDEX and objective image analysis was performed measuring contrast-to-noise ratio and signal-to-noise ratio. We found no significant differences in the Siemens Luminos unit in any of the inspected parameters. However, there was a significant difference in dose area product (37.3 %), effective dose (35.7 %) and average absorbed dose to selected individual organs (36.7 %) when the head away position of the patient was used and the image quality increased. Based on these results, we can propose that the optimal position of the patient regarding the ionizing cells is the head away position.

scholarly journals Performance of TGSE BLADE DWI in the diagnosis of cholesteatoma compared with RESOLVE DWI

2020 ◽  
Author(s):  
Yaru Sheng ◽  
Rujian Hong ◽  
Yan Sha ◽  
Zhongshuai Zhang ◽  
Kun Zhou ◽  
...  
Keyword(s):  
Image Quality ◽  
Pulse Sequence ◽  
Signal To Noise Ratio ◽  
Spin Echo ◽  
Quantitative Imaging ◽  
Geometric Distortion ◽  
Imaging Parameters ◽  
Diffusion Weighted ◽  
Ghosting Artifacts ◽  
Noise Ratio

Abstract Background: Based on the high resolution of soft tissue, MRI has gained increasing importance in the evaluation of cholesteatoma, especially diffusion-weighted imaging(DWI). The purpose of this study was to evaluate the role of 2D turbo gradient- and spin-echo (TGSE) diffusion-weighted (DW) pulse sequence with BLADE trajectory technique in the diagnosis of cholesteatoma at 3T and to qualitatively and quantitatively compare the image quality between the TGSE BLADE and RESOLVE methods.Method: A total of 42 patients (23 males, 19 females; age range, 7-65 years; mean, 40.1 years) with surgically confirmed cholesteatoma in the middle ear were enrolled in this study. All patients underwent DWI (both the prototype TGSE BLADE DWI sequence and RESOLVE DWI sequence) using a 3-T scanner with a 64-channel brain coil.Qualitative imaging parameters (imaging sharpness, geometric distortion, ghosting artifacts, and overall imaging quality) and quantitative imaging parameters (apparent diffusion coefficient [ADC], signal-to-noise ratio [SNR], contrast, and contrast-to-noise ratio [CNR] for the two diffusion acquisition techniques were assessed by two independent radiologists. Result: Comparison of the qualitative scores indicated that TGSE BLADE DWI produced less geometric distortion and ghosting artifacts (P<0.001) and higher image quality (P<0.001) than RESOLVE DWI. Comparison of the evaluated quantitative image parameters between TGSE and RESOLVE showed that TGSE BLADE DWI produced a significantly lower SNR (P<0.001) and higher parameter values (both contrast and CNR (P < 0.001)) than RESOLVE DWI.The ADC (P<0.001) measured by TGSE BLADE DWI (0.763×10-3 s/mm2) is significantly lower than that measured by RESOLVE DWI (0.928×10-3 s/mm2). Conclusion: Comparing with RESOLVE DWI, TGSE BLADE DWI can significantly improve the image quality of cholesteatoma by reducing magnetic sensitive artifacts, distortion, and blurring. TGSE BLADE DWI is more valuable for the diagnosis of small-sized (2mm) cholesteatoma lesions compare with RESOLVE DWI image. However, TGSE BLADE DWI also has some disadvantages: the whole image intensity is slightly low, so that the anatomical details of the air-bone interface are not well shown, which is the place to be improved in the future.

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