scholarly journals Penerapan Teknik Parallel Imaging Pada Pesawat MRI 0,35 Tesla Untuk Optimalisasi Kualitas Informasi Anatomi Pada MRI Lumbal Pembobotan T1WI dan T2WI Potongan Sagital

2015 ◽  
Vol 1 (1) ◽  
pp. 19-22
Author(s):  
Gatot Murti Wibowo ◽  
Dartini Dartini ◽  
Hari Prayitno
Keyword(s):  
Image Quality ◽  
Parallel Imaging ◽  
Imaging Techniques ◽  
Spin Echo ◽  
Clinical Image ◽  
Good Imaging ◽  
Scan Time ◽  
Significant Difference ◽  
Lumbar Mri

Background : Parallel imaging is one of the MRI Scanning techniques used to reduce the overall scan time when the patients with unvoluntary movement being examined with a low magnetic field of 0,35 T.  This research aims to determine the difference between the clinical image quality of the conventional turbo spin echo (TSE) with mSENSE and that of the TSE with GRAPPA parallel imaging techniques from which resulting the MRI T1 and T2 Weighted Images (T1WI and T2WI) sagittal view of lumbar spines, and to define the techniques that clinically provide the most approriate anatomical information.Methods :  This experimental study is made performed by the MRI 0.35 T in which 10 patients who had hernia nucleus pulposus (HNP) desease participated in the experiments ramdomly. The appointed Radiologists blended in the image evaluation using an image checklist to assess the visualisation of anatomical organs on the resulted sagittal lumbar MRI T1WI and T2WI. The two non-parametric statistical tools, Friedman test and the post hoc Wilcoxon matched pairs test, is used to analyze all the data descriptively. Testing the resesearch hypotheses with 95% of confident interval is to proved the differences between resulted sagittal lumbar MRI T1WI and T2WI..Results : The results shown there is a significant difference on the image quality of anatomical information when conventional TSE, parallel imaging-mSENSE and -GRAPPA, with T1WI are applied in the imaging techniques. When those imaging techniques are employed to obtain T2WI, the result is not significant in  contrast.Conclusion : Good imaging techniques with adequate clinical image quality are ranked sequently as the conventional TSE, the  mSENSE and GRAPPA.

scholarly journals Radial self-navigated native magnetic resonance angiography in comparison to navigator-gated contrast-enhanced MRA of the entire thoracic aorta in an aortic patient collective

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Martina Correa Londono ◽  
Nino Trussardi ◽  
Verena C. Obmann ◽  
Davide Piccini ◽  
Michael Ith ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Image Quality ◽  
Magnetic Resonance Angiography ◽  
Thoracic Aorta ◽  
Aortic Root ◽  
Aortic Disease ◽  
Ascending Aorta ◽  
Scan Time ◽  
Contrast Enhanced

Abstract Background The native balanced steady state with free precession (bSSFP) magnetic resonance angiography (MRA) technique has been shown to provide high diagnostic image quality for thoracic aortic disease. This study compares a 3D radial respiratory self-navigated native MRA (native-SN-MRA) based on a bSSFP sequence with conventional Cartesian, 3D, contrast-enhanced MRA (CE-MRA) with navigator-gated respiration control for image quality of the entire thoracic aorta. Methods Thirty-one aortic native-SN-MRA were compared retrospectively (63.9 ± 10.3 years) to 61 CE-MRA (63.1 ± 11.7 years) serving as a reference standard. Image quality was evaluated at the aortic root/ascending aorta, aortic arch and descending aorta. Scan time was recorded. In 10 patients with both MRA sequences, aortic pathologies were evaluated and normal and pathologic aortic diameters were measured. The influence of artifacts on image quality was analyzed. Results Compared to the overall image quality of CE-MRA, the overall image quality of native-SN-MRA was superior for all segments analyzed (aortic root/ascending, p < 0.001; arch, p < 0.001, and descending, p = 0.005). Regarding artifacts, the image quality of native-SN-MRA remained superior at the aortic root/ascending aorta and aortic arch before and after correction for confounders of surgical material (i.e., susceptibility-related artifacts) (p = 0.008 both) suggesting a benefit in terms of motion artifacts. Native-SN-MRA showed a trend towards superior intraindividual image quality, but without statistical significance. Intraindividually, the sensitivity and specificity for the detection of aortic disease were 100% for native-SN-MRA. Aortic diameters did not show a significant difference (p = 0.899). The scan time of the native-SN-MRA was significantly reduced, with a mean of 05:56 ± 01:32 min vs. 08:51 ± 02:57 min in the CE-MRA (p < 0.001). Conclusions Superior image quality of the entire thoracic aorta, also regarding artifacts, can be achieved with native-SN-MRA, especially in motion prone segments, in addition to a shorter acquisition time.

Impact on dose and image quality of a software-based scatter correction in mammography

2017 ◽  
Vol 59 (6) ◽  
pp. 649-656 ◽  
Author(s):  
Teresa Monserrat ◽  
Elena Prieto ◽  
Benigno Barbés ◽  
Luis Pina ◽  
Arlette Elizalde ◽  
...  
Keyword(s):  
Image Quality ◽  
Scatter Correction ◽  
Inverse Image ◽  
Clinical Image ◽  
Air Kerma ◽  
Average Glandular Dose ◽  
Standard Mode ◽  
Entrance Surface Air Kerma ◽  
Clinical Cases

Background In 2014, Siemens developed a new software-based scatter correction (Progressive Reconstruction Intelligently Minimizing Exposure [PRIME]), enabling grid-less digital mammography. Purpose To compare doses and image quality between PRIME (grid-less) and standard (with anti-scatter grid) modes. Material and Methods Contrast-to-noise ratio (CNR) was measured for various polymethylmethacrylate (PMMA) thicknesses and dose values provided by the mammograph were recorded. CDMAM phantom images were acquired for various PMMA thicknesses and inverse Image Quality Figure (IQFinv) was calculated. Values of incident entrance surface air kerma (ESAK) and average glandular dose (AGD) were obtained from the DICOM header for a total of 1088 pairs of clinical cases. Two experienced radiologists compared subjectively the image quality of a total of 149 pairs of clinical cases. Results CNR values were higher and doses were lower in PRIME mode for all thicknesses. IQFinv values in PRIME mode were lower for all thicknesses except for 40 mm of PMMA equivalent, in which IQFinv was slightly greater in PRIME mode. A mean reduction of 10% in ESAK and 12% in AGD in PRIME mode with respect to standard mode was obtained. The clinical image quality in PRIME and standard acquisitions resulted to be similar in most of the cases (84% for the first radiologist and 67% for the second one). Conclusion The use of PRIME software reduces, in average, the dose of radiation to the breast without affecting image quality. This reduction is greater for thinner and denser breasts.

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.

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 A comparative study on image quality of two digital intraoral sensors

2019 ◽  
Vol 48 (7) ◽  
pp. 20190063 ◽  
Author(s):  
Cinar Aziman ◽  
Kristina Hellén-Halme ◽  
Xie-Qi Shi
Keyword(s):  
Image Quality ◽  
Observer Agreement ◽  
Visual Grading ◽  
Intra Class Correlation ◽  
Subjective Image Quality ◽  
Significant Difference ◽  
General Dentists ◽  
Parallel Technique ◽  
Specialist Group

Objectives The aims of this study were to evaluate the subjective image quality and reliability of two digital sensors. In addition, the image quality of the two sensors evaluated by specialists and general dentists were compared. Methods: 30 intraoral bitewings from five patients were included in the study, 15 were exposed with a Dixi sensor (CCD-based) and 15 with a ProSensor (CMOS-based) using modified parallel technique. Three radiologists and three general dentists evaluated the images in pair. A five-point scale was used to register the image quality. Visual grading characteristics (VGC) analysis was performed to compare the image quality and the observer agreement was assessed in terms of intra class correlation co-efficient. Results No statistically significant difference was found on image quality between the sensors. The average scores of the observer agreement were moderate with an average of 0.66 and an interval of 0.30 to 0.87, suggesting that there was a large variation on preference of image quality. However, there was a statistically significant difference in terms of the area under the VGC- curves between the specialist group and the general dentist group ( p = 0.043), in which the specialist group tended to favor the ProSensor. Conclusions Subjective image quality of the two intraoral sensors were comparable when evaluated by both general and oral radiologists. However, the radiologists seemed to prefer the ProSensor to the Dixi as compared to general dentists. Inter- observer conformance showed a large variation on the preference of the image quality.

A Virtual Image Chain for Perceived and Clinical Image Quality of Medical Display

2008 ◽  
Vol 4 (4) ◽  
pp. 356-368 ◽  
Author(s):  
CÉdric Marchessoux ◽  
Tom Kimpe ◽  
Tom Bert
Keyword(s):  
Image Quality ◽  
Clinical Image ◽  
Virtual Image

Digital Luminescence Radiography Using a Chest Phantom

1993 ◽  
Vol 34 (5) ◽  
pp. 440-444 ◽  
Author(s):  
K. Lyttkens ◽  
M. Kehler ◽  
B. Andersson ◽  
S. Carlsen ◽  
A. Ebbesen ◽  
...  
Keyword(s):  
Image Quality ◽  
Operating Characteristic ◽  
Roc Curves ◽  
Diagnostic Image Quality ◽  
Diagnostic Image ◽  
Digital Radiographs ◽  
Significant Difference ◽  
Digital Luminescence Radiography ◽  
Optical Discs

With the introduction of picture and archiving communicating systems an alternative image display for the wards might be a personal computer (PC). The intention with this study was to evaluate the diagnostic image quality of the monitor of a PC compared to that of a workstation. Eighty-five digital radiographs of a chest phantom with simulated tumors in the mediastinum and right lung were saved on optical discs. The examinations were reviewed by 4 radiologists on a monitor at a workstation and at a PC, and receiver operating characteristic (ROC) curves were constructed. No significant difference was found between performance of the PC and the workstation.

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 Sparse 3D contrast-enhanced whole-heart imaging for coronary artery evaluation

Herz ◽  
2022 ◽  
Author(s):  
Uzair Ansari ◽  
Sonja Janssen ◽  
Stefan Baumann ◽  
Martin Borggrefe ◽  
Stephan Waldeck ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Image Quality ◽  
Cardiac Computed Tomography ◽  
Acquisition Time ◽  
Cohen’S Kappa ◽  
Cohen's Kappa ◽  
Contrast Enhanced ◽  
Significant Difference ◽  
Whole Heart

Abstract Background We investigated the feasibility of evaluating coronary arteries with a contrast-enhanced (CE) self-navigated sparse isotropic 3D whole heart T1-weighted magnetic resonance imaging (MRI) study sequence. Methods A total of 22 consecutive patients underwent coronary angiography and/or cardiac computed tomography (CT) including cardiac MRI. The image quality was evaluated on a 3-point Likert scale. Inter-reader variability for image quality was analyzed with Cohen’s kappa for the main coronary segments (left circumflex [LCX], left anterior descending [LAD], right coronary artery [RCA]) and the left main trunk (LMT). Results Inter-reader agreement for image quality of the coronary tree ranged from substantial to perfect, with a Cohen’s kappa of 0.722 (RCAmid) to 1 (LCXprox). The LMT had the best image quality. Image quality of the proximal vessel segments differed significantly from the mid- and distal segments (RCAprox vs. RCAdist, p < 0.05). The LCX segments showed no significant difference in image quality along the vessel length (LCXprox vs. LCXdist, p = n.s.). The mean acquisition time for the study sequence was 553 s (±46 s). Conclusion Coronary imaging with a sparse 3D whole-heart sequence is feasible in a reasonable amount of time producing good-quality imaging. Image quality was poorer in distal coronary segments and along the entire course of the LCX.

Sign in / Sign up

Export Citation Format

Share Document