Using Fourier ptychography microscopy to achieve high-resolution chromosome imaging: an initial evaluation

Abstract

. Significance: Searching analyzable metaphase chromosomes is a critical step for the diagnosis and treatment of leukemia patients, and the searching efficiency is limited by the difficulty that the conventional microscopic systems have in simultaneously achieving high resolution and a large field of view (FOV). However, this challenge can be addressed by Fourier ptychography microscopy (FPM) technology. Aim: The purpose of this study is to investigate the feasibility of utilizing FPM to reconstruct high-resolution chromosome images. Approach: An experimental FPM prototype, which was equipped with or objective lenses to achieve a theoretical equivalent NA of 0.48 and 0.63, respectively, was developed. Under these configurations, we first generated the system modulation transfer function (MTF) curves to assess the resolving power. Next, a group of analyzable metaphase chromosomes were imaged by the FPM system, which were acquired from the peripheral blood samples of the leukemia patients. The chromosome feature qualities were evaluated and compared with the results accomplished by the corresponding conventional microscopes. Results: The MTF curve results indicate that the resolving power of the FPM system is equivalent and comparable to the conventional microscope, whereas the performance of the FPM system is close to the conventional microscope. When imaging the chromosomes, the feature qualities of the FPM system are comparable to the results under the conventional lens, whereas the feature qualities of the FPM system are better than the conventional lens and comparable to the conventional lens. Conclusions: This study initially verified that it is feasible to utilize FPM to develop a high-resolution and wide-field chromosome sample scanner.

Analysis of postreconstruction digital refocusing in Fourier ptychographic microscopy

“…The second approach would be to perform FPM imaging in its aperture scanning modality. 8,27,[29][30][31] In this modality, instead of using a tilted illumination to selectively move different portions of the angular spectrum into the collecting numerical aperture of the microscope, we use a high NA imaging system and illuminate the sample at normal incidence. To select different portions of the angular spectrum for detection, an aperture is then scanned at the Fourier plane of the microscope.…”

“…1,2 FPM has significant advantages in achieving wide-field and high-resolution imaging. [3][4][5][6][7][8] In combination with other imaging modalities, it can additionally achieve 3D, high-speed, or subwavelength imaging. [9][10][11][12][13] The key concept in FPM is that synthetic aperture and phase retrieval can be combined to increase the space-bandwidth product of the optical system.…”

Peripheral Blood Leukocyte Detection Based on an Improved Detection Transformer Algorithm

“…Based on the advantages of FPM, in just a few years of development, it has been applied in many fields, such as bioimaging of living samples [ 15 ], cell detection [ 16 ], cell counting [ 17 , 18 ], and digital pathology [ 19 ]. In recent years, FPM has been improved in terms of implementation methods [ 20 , 21 , 22 ], imaging performance [ 23 , 24 , 25 ], and reconstruction efficiency [ 26 , 27 , 28 ]. These applications and improvements in biomedicine also further reflect the great potential of FPM.…”

Evaluating the depth of field for Fourier ptychography microscopy

“…Additionally, since the raw patterns are acquired under low magnification objective lens (e.g. 4×) and the depth of the field (DOF) of the raw patterns determines the DOF of the final image, FPM has a larger DOF as compared to conventional microscopes of comparable numerical aperture (NA) 7 . As a result, the FPM scanner does not require high precision moving stages, which vastly reduces the total cost of the system.…”