Digital Slide Imaging in Cervicovaginal Cytology: A Pilot Study

Abstract

Context.-Digital whole slide imaging is the anticipated future of anatomic pathology, where sign-out of glass slides will be replaced by scanned images. Whole slide imaging has been successfully used in surgical pathology, but its usefulness and clinical application have been limited in cytology for several reasons, including lack of availability of z-axis depth focusing and large file size. Recently, several systems have become available in the United States for whole slide imaging with z-axis technology.Objective.-To determine the accuracy and efficiency of whole slide imaging, as compared with traditional glass slides, for use in cervicovaginal diagnostic cytology.Design.-Eleven cervicovaginal cytology cases (ThinPrep and SurePath) scanned at 320, 340, and 340 z-stack magnifications using the BioImagene iScan Coreo Au 3.0 scanner were evaluated by 4 cytotechnologists and 3 pathologists in a blinded study. Different magnification scans were recorded as separate cases and presented in a randomized sequence. Corresponding glass slides were also reviewed. For each case, the diagnoses and total time to reach each diagnosis were recorded.Results.-Diagnostic accuracy was higher and average time per case was lower with glass slides as compared with all digital images. Among the digital images, the 340 or 340 z-stack had the highest diagnostic accuracy and lowest interpretation time.Conclusions.-Whole slide imaging is a viable option for the purposes of teaching and consultations, and as a means of archiving cases. However, considering the large file size and total time to reach diagnosis on digital images, whole slide imaging is not yet ready for daily cervicovaginal diagnostic cytology screening use.(Arch Pathol Lab Med. 2013;137:618-624; doi: 10.5858/ arpa.2012-0430-OA) D igital imaging is the creation, storage, and transmission of an image file using a computer and is considered by many to be the future of anatomic pathology. Most pathologists currently use some form of digital imaging, such as static images obtained by microscope-mounted optical cameras. Within the field of cytology, digital images are routinely being used for automated computer-assisted screening of Papanicolaou test slides, as well as for training and education. Proficiency testing is currently performed on glass slides, though the future use of digital slides is anticipated. The development of greater image quality and resolution within digital pathology has promoted the use of telepathology, including telecytology, which has been shown to be acceptable for both adequacy checks and rapid cytology diagnoses. [1][2][3][4] Other uses of digital imaging in pathology include image-enhanced reports, live imaging through robotic microscopy, 5 remote surgical frozen section review, 6,7 quality assurance testing, 3 and image cytometry/ analysis.Whole slide imaging (WSI), a subset of digital imaging, is the process of scanning an entire glass slide and converting the data into a high-resolution digital image that is viewed and manipulated on a computer....

Digital Pathology and Federalism

“…[9][10][11][12] Indeed, in both surgical pathology and cytopathology, [13][14][15] digital pathology is poised to do no less than ''redefine how pathology is practiced and the role of the pathologist.'' 16 Of course, substantial challenges accompany the establishment of digital pathology, including technical and workflow issues, standardization, and whole-slide imaging validation, and these are currently being addressed by the College of American Pathologists and other organizations.…”

A method for quantitative analysis of clump thickness in cervical cytology slides

“…With WSI, the specimens are first scanned as digital images and suspicious cells can be tirelessly and consistently detected by digital image processing algorithms [27]. However, WSI faces some significant issues limiting its adoption in clinical use, such as poor standardisation of image quality and resolution, large file size of the digitised slides and slow acquisition speeds, especially when multiple focal planes are required [26,7]. Among them, the scan speed is the main bottleneck, because acquisition has be fast enough for clinical use, but improved image quality and acquisition of multiple focal planes both result in significantly longer scan times.…”

“…In addition, important diagnostic cells are often found within these cell clumps, such as secretory cells from the endocervic and low-grade squamous intraepithelial lesions [15]. Therefore, it is no surprise to see that the acquisition of multiple focal planes achieves better diagnostic performances than acquiring only one or a few focal planes [26,8]. Additionally, interpreting cellular objects requires the microscope to operate at high magnification (40x), preferably at resolutions close to the diffraction limit (∼0.2µm/pixel), where the depth-of-field is reduced to around one micron [5].…”

“…For example, it was first shown that digital cervical cytology slides with seven focal planes achieved higher diagnostic accuracy than those of a single focal plane (both at 40X), but both were outperformed by conventional glass slides [26]. Another study reported that cervical specimens scanned with 21 focal planes at a 1.5µm interval achieved better diagnostic accuracy than those scanned with 5 focal planes at 1µm interval [8].…”

Desenvolvimento de uma laminoteca digital

“…Na citopatologia, os microscópios óticos têm vindo a ser continuamente desenvolvidos com vista à melhoria contínua da ergonomia e da qualidade de imagem. Neste sentido, o avanço da tecnologia aliado aos constantes desafios do diagnóstico impulsionaram o desenvolvimento de microscópios com a capacidade de digitalização de preparações citológicas cuja utilidade tem sido crescente entre os profissionais da área [1][2][3][4][5][6] . Na Anatomia Patológica, a digitalização de amostras têm revolucionado as áreas da histologia, citologia, imunohistoquímica e citogenética, contribuindo para uma automatização diagnóstico 1,6 .…”