scholarly journals Retinal image quality with multifocal, EDoF, and accommodative intraocular lenses as studied by pyramidal aberrometry

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jorge L. Alio ◽  
Francesco D’Oria ◽  
Francesca Toto ◽  
Joan Balgos ◽  
Antonio Palazon ◽  
...  
Keyword(s):  
Image Quality ◽  
Retinal Image ◽  
Quality Parameters ◽  
Intraocular Lenses ◽  
Clinical Image ◽  
Control Group ◽  
Strehl Ratio ◽  
High Order Aberration ◽  
I 11 ◽  
Group B

Abstract Background To study and compare the clinical optical image quality following implantation with different premium IOLs by analysing the point spread function (PSF) Strehl ratio using a pyramidal wavefront sensor (PWS)-based aberrometer. Methods This study included 194 eyes implanted with: (a) 19 AcrySof SA60AT (control group); (b) 19 Miniwell; (c) 24 LENTIS Mplus LS-313 MF30; d) 33 LENTIS Mplus LS-313 MF15; (e) 17 AkkoLens Lumina; (f) 31 AT LISA Tri 839MP; (g) 20 Precizon Presbyopic; (h) 20 AcrySof IQ PanOptix; (i) 11 Tecnis Eyhance. Main outcome measures were PSF Strehl ratio, PSF Strehl ratio excluding second-order aberrations (PSFw2), total root mean square (RMS), low-order aberration (LOA) and high-order aberration (HOA) RMS measured by PWS aberrometer. Results AT LISA Tri had the highest PSFw2 Strehl ratio at both 3.0- and 4.0-mm pupil size (0.52 ± 0.14 and 0.31 ± 0.10; P < 0.05), followed by SA60AT (0.41 ± 0.11 and 0.28 ± 0.07) and PanOptix (0.4 ± 0.07 and 0.26 ± 0.04). AT LISA Tri was found to provide a significantly better retinal image quality than PanOptix at both 3.0 mm (P < 0.0001) and 4.0 mm (P = 0.004). Mplus MF15 was found to be significantly better than Mplus MF30 at both 3.0 mm (P < 0.0001) and 4.0 mm (P = 0.002). Total RMS, LOA RMS, HOA RMS, PSF Strehl ratio and PSFw2 varied significantly between the studied groups (P < 0.001). Conclusions Far distance clinical image quality parameters measured by PWS aberrometer differed significantly according to the technology of the implanted lens. AT LISA Tri, SA60AT and PanOptix showed the highest values of far distance retinal image quality, while the lowest PSFw2 Strehl ratios were displayed by Miniwell, Mplus MF30 and Precizon Presbyopic.

scholarly journals Retinal Optical Quality of Multifocal Refractive and Monofocal Intraocular Lenses

Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 559
Author(s):  
Francesco D’Oria ◽  
Ali Nowrouzi ◽  
Jorge L. Alio del Barrio ◽  
Francesco Versaci ◽  
Jorge L. Alio
Keyword(s):  
Image Quality ◽  
Quality Parameters ◽  
Optical Quality ◽  
Intraocular Lenses ◽  
Clinical Image ◽  
Control Group ◽  
Strehl Ratio ◽  
Group 2 ◽  
Group B

(1) Background: This study aimed to evaluate and compare the clinical optical image quality following implantation with different premium IOLs by the analysis of the point spread function (PSF) Strehl ratio using a Pyramidal WaveFront-based sensor (PWS) aberrometer at two different pupil sizes. (2) Methods: This study included 96 eyes of 70 patients implanted with: (1) 19 AcrySof SA60AT (control group); (2) 24 LENTIS Mplus LS-313 MF30; (3) 33 LENTIS Mplus LS-313 MF15; and (4) 20 Precizon Presbyopic. Main outcome measures were PSF Strehl ratio, PSF Strehl ratio excluding second-order aberrations (PSFw2), total root-mean-square (RMS), and low- and high-order aberrations’ RMS measured by PWS aberrometer. Results: SA60AT had the highest significant PSFw2 Strehl ratio at both 3- and 4-mm pupil size (0.41 ± 0.11 and 0.28 ± 0.07) followed by LENTIS Mplus 15 (group C, 0.35 ± 0.1 and 0.21 ± 0.06) and a near tie between LENTIS MPLUS 30 (group B, 0.27 ± 0.08 and 0.18 ± 0.06) and Precizon Presbyopic (group D, 0.27 ± 0.07 and 0.17 ± 0.04). MPlus MF15 was found to be significantly better than MPlus MF30 at both 3.00 mm (p < 0.0001) and 4.00 mm (p = 0.002). (4) Conclusions: The PSFw2 represents a new tool to objectively evaluate the far distance retinal image quality of multifocal IOLs, and the far distance clinical image quality parameters measured by PWS aberrometer differed significantly according to the technology of the implanted lens.

scholarly journals Comparison of retinal image quality with spherical and customized aspheric intraocular lenses

2012 ◽  
Vol 3 (4) ◽  
pp. 681 ◽  
Author(s):  
Huanqing Guo ◽  
Alexander V. Goncharov ◽  
Chris Dainty
Keyword(s):  
Image Quality ◽  
Retinal Image ◽  
Intraocular Lenses

First experiences of a low-dose protocol for CT-guided musculoskeletal biopsies combining different radiation dose reduction techniques

2019 ◽  
Vol 61 (1) ◽  
pp. 28-36
Author(s):  
Zlatan Alagic ◽  
Haris Alagic ◽  
Robert Bujila ◽  
Subhash Srivastava ◽  
Saif Jasim ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Success Rate ◽  
Low Dose ◽  
Quality Parameters ◽  
Ct Guided ◽  
Protocol Group ◽  
Group A ◽  
The Mean ◽  
Group B

Background The use of computed tomography (CT) for image guidance during biopsies is a powerful approach. The method is, however, often associated with a significant level of radiation exposure to the patient and operator. Purpose To investigate if a low-dose protocol for CT-guided musculoskeletal (MSK) biopsies, including a combination of different radiation dose (RD) techniques, is feasible in a clinical setting. Material and Methods Fifty-seven patients underwent CT-guided fine-needle aspiration cytology (FNAC) utilizing the low-dose protocol (group A). A similar number of patients underwent CT-guided FNAC using the reference protocol (group B). Between-group comparisons comprised radiation dose, success rate, image quality parameters, and workflow. Results In group A, the mean total dose-length product (DLP) was 41.2 ± 2.9 mGy*cm, which was statistically significantly lower than of group B (257.4 ± 22.0 mGy*cm), corresponding to a mean dose reduction of 84% ( P<0.001). The mean CTDIvol for the control scans were 1.88 ± 0.09 mGy and 13.16 ± 0.40 mGy for groups A and B, respectively ( P < 0.001). The success rate in group A was 91.2% and 87.9% in group B ( P = 0.56). No negative effect on image-quality parameters, time of FNAC, and number of control scans were found. Conclusion We successfully developed a low-dose protocol for CT-guided MSK biopsies that maintains diagnostic accuracy and image quality at a fraction of the RD compared to the reference biopsy protocol at our clinic.

The Value of Low-dose Prospective Dual-energy Computed Tomography with Iodine Mapping in the Diagnosis of Gastric Cancer

2020 ◽  
Vol 16 (4) ◽  
pp. 433-437
Author(s):  
Lifeng Wang ◽  
Xingxing Jin ◽  
Zhenguo Qiao ◽  
Bin Xu ◽  
Jiaqing Shen
Keyword(s):  
Gastric Cancer ◽  
Computed Tomography ◽  
Image Quality ◽  
Radiation Dose ◽  
Low Dose ◽  
Preoperative Staging ◽  
Control Group ◽  
Imaging Quality ◽  
Group A ◽  
Group B

Objectives: This study investigated the radiation dose and value of prospective dualenergy computed tomography (DECT) in the diagnosis of gastric cancer. Methods: Sixty patients scheduled for computed tomography (CT) for preoperative staging were divided into two groups. Thirty patients (Group A) underwent a single contrast-enhanced abdominal CT acquisition using a dual-source mode (100 kV/140 kV). Weighted average images of the two-kilovolt acquisitions and iodine maps were created. The remaining 30 patients underwent a standard CT scan (Group B). Two observers performed a blinded read of the images for gastric lesions, evaluating the image quality and recording effective dose. Results: During the blinded read, observers found 90% (27/30) of the cancers in both groups. The mean imaging quality scores were 2.1±0.9 for Group A, and 2.3±1.1 for Group B. The effective mean doses were 6.59±0.59 mSv and 25.86±0.44 mSv for Groups A and B, respectively. Compared with the control group (B), the imaging quality in the low-dose group decreased a little, but the radiation dose substantially decreased by 74.6%. Conclusion: The new DECT technique is valuable for examining gastric cancer patients. The dualkV scan mode can substantially reduce radiation dose while preserving good diagnostic image quality.

scholarly journals The Value of Iterative Reconstruction of Algorithm-Based Coronary Artery Computed Tomography Imaging in the Diagnosis of Old Myocardial Infarction

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Liang Guo ◽  
Lu Ren ◽  
Yajun Shao ◽  
Wei Li ◽  
Shangxian Yu
Keyword(s):  
Coronary Artery ◽  
Image Quality ◽  
Iterative Reconstruction ◽  
Reconstruction Algorithm ◽  
Quality Parameters ◽  
Control Group ◽  
Iterative Reconstruction Algorithm ◽  
Algebraic Iterative Reconstruction ◽  
Experimental Group ◽  
Number Of Iterations

The objective of this study was to compare the diagnostic value of computed tomography (CT) based on iterative reconstruction algorithm in old myocardial infarction (OMI), thereby providing theoretical guidance and practical basis for clinical treatment. In this study, in order to provide theoretical guidance and practical basis for the diagnosis and treatment of clinical OMI, 10 patients with OMI were selected and divided into two groups, with 5 patients in each group. In addition, an algebraic iterative reconstruction algorithm is constructed, which starts from the initial estimation value, compares, and corrects the estimation results and the measured results continuously until the error between the two results is less than the predetermined value. The experimental group was optimized by algebraic iterative reconstruction algorithm, and the control group was reconstructed by the hospital original method. The image quality parameters under different iteration times were analyzed and compared to obtain the optimal iteration times. The value of iterative reconstruction algorithm in clinical diagnosis was investigated by analyzing the time of drawing and the accuracy of diagnosis after drawing. Through the analysis and comparison of the image quality parameters of the patients from the experimental group, it was found that the image quality firstly increased with the increase in the number of iterations but decreased with the increase of the number of iterations after a certain number of iterations. The results showed that the optimal number of iterations was 13 times. The drawing time of the experimental group and the control group was 54.27 minutes and 117.87 minutes in turn, so the difference between the two groups was significant ( P < 0.05 ). Besides, there was a statistically marked difference in the accuracy rate of the experimental group (93.33%) and the control group (73.33%) ( P < 0.05 ). In conclusion, the time required for coronary artery CT imaging using algebraic iterative reconstruction algorithm was greatly reduced and the diagnostic accuracy was hugely improved. Therefore, the coronary artery CT imaging based on iterative reconstruction algorithm could make more effective use of medical resources and improve the diagnostic accuracy in the diagnosis of OMI.

scholarly journals Optical bench simulation for intraocular lenses using field-tracing technology

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0250543
Author(s):  
Seok Ho Song ◽  
In Seok Song ◽  
Se Jin Oh ◽  
Hyeck-Soo Son ◽  
Min Ho Kang
Keyword(s):  
Image Quality ◽  
Ray Tracing ◽  
Retinal Image ◽  
Spherical Aberration ◽  
Experimental Results ◽  
Intraocular Lenses ◽  
Optical Simulation ◽  
Optical Bench ◽  
Eye Model ◽  
Wave Nature

Purpose To evaluate the image quality of intraocular lenses (IOLs) using field-tracing optical simulation and then compare it with the image quality using conventional ray-tracing simulation. Methods We simulated aspheric IOLs with a decenter, tilt, and no misalignment using an aspheric corneal eye model with a positive spherical aberration. The retinal image, Strehl ratio, and modulation transfer function (MTF) were compared between the ray-tracing and field-tracing optical simulation and confirmed by the results reported in an in vitro experiment using the same eye model. Results The retinal image showed interference fringes from target due to diffraction from the object in a field-tracing simulation. When compared with the experimental results, the field tracing represented the experimental results more precisely than ray tracing after passing over 400 μm of the decentration and 4 degrees of the tilt of the IOLs. The MTF values showed similar results for the case of no IOL misalignment in both the field tracing and ray tracing. In the case of the 200-μm decentration or 8-degree tilt of IOL, the field-traced MTF shows lower values than the ray-traced one. Conclusions The field-tracing optical bench simulation is a reliable method to evaluate IOL performance according to the IOL misalignment. It can provide retinal image quality close to real by taking into account the wave nature of light, interference and diffraction to explain to patients having the IOL misalignment.

scholarly journals Novel Approach for MRI Image Quality Analysis by Hybrid Preprocessing Techniques

2020 ◽  
Vol 6 (5) ◽  
pp. 27-32
Author(s):  
K Phaneendra ◽  
B Tirupathi Rao ◽  
B Nikhila Sree ◽  
J Haswanth Kumar ◽  
B Harshavardhan Raju
Keyword(s):  
Image Quality ◽  
Signal To Noise Ratio ◽  
Quality Parameters ◽  
Quality Analysis ◽  
Clinical Image ◽  
Discrete Wavelet ◽  
Clinical Images ◽  
Novel Approach ◽  
Fundamental Goal ◽  
Information Image

Image pre-preparing methods are utilized to improve the nature of a image before handling into an application. This uses a little neighborhood of a pixel in an information image to get another splendor esteem in the yield image. These pre-preparing methods are likewise called as filtration and goals upgrade. The clinical image quality parameters are fundamentally clamor and goals. The fundamental goal of this paper is to improve the image quality by denoising and goals upgrade. A large portion of the imaging methods are corrupted by clamor. So as to protect the edges and form data of the clinical images, the effective denoising and an improved upgrade method is required. This paper focuses the normal, middle and wiener sifting for image denoising and an addition based Discrete Wavelet Transform (DWT) strategy for goals improvement. The presentation of these strategies is assessed utilizing Peak Signal to Noise Ratio (PSNR). From the outcomes, it uncovers that the effective denoising and goals upgrade method is basic for image pre-handling.

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