Digital image documentation for quality assessment

Image standards in tissue-based diagnosis (diagnostic surgical pathology)

Background

Progress in automated image analysis, virtual microscopy, hospital information systems, and interdisciplinary data exchange require image standards to be applied in tissue-based diagnosis.

Aims

To describe the theoretical background, practical experiences and comparable solutions in other medical fields to promote image standards applicable for diagnostic pathology.

Theory and experiences

Images used in tissue-based diagnosis present with pathology – specific characteristics. It seems appropriate to discuss their characteristics and potential standardization in relation to the levels of hierarchy in which they appear. All levels can be divided into legal, medical, and technological properties. Standards applied to the first level include regulations or aims to be fulfilled. In legal properties, they have to regulate features of privacy, image documentation, transmission, and presentation; in medical properties, features of disease – image combination, human – diagnostics, automated information extraction, archive retrieval and access; and in technological properties features of image acquisition, display, formats, transfer speed, safety, and system dynamics. The next lower second level has to implement the prescriptions of the upper one, i.e. describe how they are implemented. Legal aspects should demand secure encryption for privacy of all patient related data, image archives that include all images used for diagnostics for a period of 10 years at minimum, accurate annotations of dates and viewing, and precise hardware and software information. Medical aspects should demand standardized patients' files such as DICOM 3 or HL 7 including history and previous examinations, information of image display hardware and software, of image resolution and fields of view, of relation between sizes of biological objects and image sizes, and of access to archives and retrieval. Technological aspects should deal with image acquisition systems (resolution, colour temperature, focus, brightness, and quality evaluation procedures), display resolution data, implemented image formats, storage, cycle frequency, backup procedures, operation system, and external system accessibility. The lowest third level describes the permitted limits and threshold in detail. At present, an applicable standard including all mentioned features does not exist to our knowledge; some aspects can be taken from radiological standards (PACS, DICOM 3); others require specific solutions or are not covered yet.

Conclusion

The progress in virtual microscopy and application of artificial intelligence (AI) in tissue-based diagnosis demands fast preparation and implementation of an internationally acceptable standard. The described hierarchic order as well as analytic investigation in all potentially necessary aspects and details offers an appropriate tool to specifically determine standardized requirements.

Medical laboratory informatics

Laboratory informatics is the application of computers and information systems to information management in the pathology laboratory. Effective information management is crucial to the success of pathologists and laboratorians. Informatics has become one of the key pillars of pathology, and the requirement for skilled informaticists in the laboratory has quickly grown. This article provides a wide-ranging review of pertinent aspects of laboratory informatics, and deals with important technical and management processes. Topics covered include personal computing, networks, databases, fundamentals and advanced functions of the laboratory information system, interfaces and standards, digital imaging, coding, hospital information systems and electronic medical records.

A comparison of colour micrographs obtained with a charged couple device (CCD) camera and a 35-mm camera

PURPOSE

The purpose of this study was to determine if micrographs produced with a colour charged couple device (CCD) camera were comparable in quality to micrographs obtained with a 35-mm colour film camera. The Axiocam (Zeiss, Jena, Germany) CCD camera produced images of 3900 x 3090 pixels.

METHODS

Each picture in a series of 50 pairs of film and digital micrographs was rated independently by each of three observers on the categories of colour, detail and overall impression. A total of 28 of the 50 pairs of micrographs were discarded due to colour differences.

RESULTS

Digital micrographs were rated lower on colour and higher on detail compared to film micrographs. The film and digital micrographs were rated equally on overall impression. The difference in colour between film and digital micrographs can be compensated for using image processing software on the digital image. However, such manipulation was not carried out as part of the present study. The study originally included 50 digital micrographs and 50 film micrographs. The micrographs were paired and 22 of the 50 pairs of micrographs were assessed. Thus 28 pairs were not evaluated due to colour differences in the non-manipulated pictures. The interobserver difference on colour in the remaining 22 pairs given as mean square +/- standard error of the mean was - 0.27 +/- 0.10, 0.62 +/- 0.10 and 0.90 +/- 0.11. The interobserver difference on detail was - 0.48 +/- 0.10, 0.95 +/- 0.10 and 1.43 +/- 0.10. The interobserver difference on overall impression was - 0.70 +/- 0.10, 0.57 +/- 0.10 and 1.27 +/- 0.10. All the results differed significantly (p < 0.001).

CONCLUSION

Digital micrographs are sufficient in detail, colour and overall impression to replace the traditional 35-mm film recordings for use in histopathology.

Digital photography: a primer for pathologists

The computer and the digital camera provide a unique means for improving hematology education, research, and patient service. High quality photographic images of gross specimens can be rapidly and conveniently acquired with a high-resolution digital camera, and specialized digital cameras have been developed for photomicroscopy. Digital cameras utilize charge-coupled devices (CCD) or Complementary Metal Oxide Semiconductor (CMOS) image sensors to measure light energy and additional circuitry to convert the measured information into a digital signal. Since digital cameras do not utilize photographic film, images are immediately available for incorporation into web sites or digital publications, printing, transfer to other individuals by email, or other applications. Several excellent digital still cameras are now available for less than 2,500 dollars that capture high quality images comprised of more than 6 megapixels. These images are essentially indistinguishable from conventional film images when viewed on a quality color monitor or printed on a quality color or black and white printer at sizes up to 11x14 inches. Several recent dedicated digital photomicroscopy cameras provide an ultrahigh quality image output of more than 12 megapixels and have low noise circuit designs permitting the direct capture of darkfield and fluorescence images. There are many applications of digital images of pathologic specimens. Since pathology is a visual science, the inclusion of quality digital images into lectures, teaching handouts, and electronic documents is essential. A few institutions have gone beyond the basic application of digital images to developing large electronic hematology atlases, animated, audio-enhanced learning experiences, multidisciplinary Internet conferences, and other innovative applications. Digital images of single microscopic fields (single frame images) are the most widely utilized in hematology education at this time, but single images of many adjacent microscopic fields can be stitched together to prepare "zoomable" panoramas that encompass a large part of a microscope slide and closely simulate observation through a real microscope. With further advances in computer speed and Internet streaming technology, the virtual microscope could easily replace the real microscope in pathology education. Later in this decade, interactive immersive computer experiences may completely revolutionize hematology education and make the conventional lecture and laboratory format obsolete. Patient care is enhanced by the transmission of digital images to other individuals for consultation and education, and by the inclusion of these images in patient care documents. In research laboratories, digital cameras are widely used to document experimental results and to obtain experimental data.

What Is a Picture Worth?: Digital Imaging Applications in Autopsy Reports

Context.—An image-enhanced report (IER) containing color digital images can serve as an educational tool and document important gross and microscopic findings in anatomic pathology.

Objective.—To determine the clinical impression of IERs on an academic autopsy service.

Design.—Autopsy IERs were initiated at this institution in December 2001. From January 2002 to July 2003, 261 hospital-service autopsies were performed; color images were produced for 39 (15%) of these autopsies. Of these IERs, 29 were distributed to 74 hospital-employed physicians. Each hospital physician recipient was sent a 6-question e-mail survey to evaluate his or her impression of image quality and added value.

Results.—Of the 74 hospital-employed physicians sent an IER, 41 responded to the survey (response rate, 55%). Twenty-one respondents recalled receiving a report with color images. Image quality was uniformly rated as good or excellent. Ninety-five percent thought the images increased their understanding of the report, and 76% thought that the images increased the utility of the report. All respondents stated they would (or did) use the images for educational purposes. Twenty-one percent of all respondents thought the presence of color images would increase their likelihood of requesting a future autopsy.

Conclusions.—Color digital images are perceived as a valuable addition to the autopsy report. Although clinicians did not consider color images a strong motivator to request a future autopsy, most thought that the images enhanced their understanding and the utility of the report. All respondents stated they would use the images to educate themselves, medical students, residents, and/or the patient's family.