Automated Imaging In Cytology Flashcards
How many individual features are evaluated by the BD Focalpoint system? How does it do this?
Up to 300 individual features are evaluated by the BD Focalpoint slide profiler using both morphometric and densiometric algorithms.
What percentage of successful processed slides does the BD Focalpoint slide profiler identify as requiring no further review (NFR)?
Up to 25%
The BD Focalpoint profiler can be used in conjunction with a Guided Screener Workstation. What functionality will this add?
When used in conjunction with a BD Focalpoint guided screener workstation the 10 highest scoring fields of view (FOV) from each qualified slide are presented to the screener for review through the use of an automated stage fitted to a standard laboratory microscope.
List some of the key dates for the approval of the use of the FDA Focalpoint slide profiler.
1995 - FDA approved its use for QC of conventional smears.
1998 - FDA approved its used for primary screening of conventional smears.
2001 - FDA approved its use for primary screening of SurePath slides.
2008 - FDA approval was granted to use both the BD Focalpoint slide profiler and the BD Focalpoint GS imaging system together for the primary screening of SurePath slides.
How many slides per 24 hours can the BD Focalpoint system process on average?
The machines can be run 24/7 and process 412 slides every 24 hours.
This can amount to up to 144k slides per year if the machines are run 7 days a week.
Can the BD Focalpoint system be used with thinprep slides?
No. The system cannot scan thinprep slides.
What human processing steps are required when using the BD Focalpoint system?
It is a ‘load and leave’ system.
You add a barcode and the labelled SurePath slides to a slide tray (8 slides per tray).
The slide trays are then loaded onto the input hopper of the profiler with a maximum of 36 slide trays (288 slides) loaded at any one time.
Racks can be loaded and unloaded at any time. Minimum of 120 slides per run.
What basic steps occur during the automated processing steps of the BD Focalpoint profiler?
There is a system integrity test and then slide scanning takes place.
What the system integrity processing step of the BD Focalpoint system entail?
The system integrity step is performed at the beginning and end of each slide tray. It characterises the performance of the mechanical, optical and electrical subsystems.
The test ensures optimal functioning of the system.
If the test fails then the 8 slides from the tray will need to be re run.
The system integrity test validates the performance of the BD Focalpoint system both before and after each slide tray.
What processes take place in the BD Focalpoint system after the system integrity test to prepare for slide scanning?
1) . Barcode on the slide tray is read.
2) . Tray is positioned beneath the microscope.
3) . Touch sensor detects presence and orientation of slide.
4) . Barcode of first slide in tray is read.
5) . Slide running can begin.
Describe what take place during the slide scanning process of the BD Focalpoint system.
A 4X low res scan takes place followed by a 20X hi res scan.
The slide is scanned three times using the 4X objective. Top to bottom, left to right, middle to outward (spiral). This generates a 3D map of the entire cell deposition area.
Each 4X field of view is then divide into 25 subsections. Each subsection is then scanned using a 20X objective and a SIL and GRP score are given to each subsection (between 1 and 10). 1000 of the highest scoring 20X subsections will go for further analysis.
A 20X scan of the highest scoring subsections then takes place. Each FOV is scanned twice. A high resolution image is acquired for each of the 1000 FOVs. Segmentation of the image takes place of the acquired FOV image whereby meaningful objects are separated from the background. Objects are classified as single cells, groups and thick groups. A single cell, group and thick group score is given for each FOV. The FOV scores are accumulated and integrated into a final score between 0 and 1.
Focalpoint uses densiometric and morphometric algorithms to determine slide score. More than 300 different features are calculated within a tree classification system (e.g. Size of nuclei, texture of nuclei, cytoplasm features, nuclear density, NC ratio, contrast etc).
Describe the BD Focalpoint slide profiler user workflow.
Slides are scanned and then are classified as either qualified or unqualified slides.
Qualified slides will be split into groups for review and no further review.
Unqualified slides will be re run or a process review will take place. They may require manual screening.
Describe the evaluation of slides that have qualified and been categorised for review.
Qualified slides for review will be visually evaluated.
A minimum of 75% of qualified slides will be put for review.
Slides adequacy information is evaluated including squamous component, endocervical component, inflammation and obscuration.
Slides are ranked for likelihood of abnormality.
What happens to qualified slides that are categorised as needing no further review.
These slides are to be archived without visual inspection.
A maximum of 25% of qualified slides should be categorised as in need of no further review but the number should be as close to 25% as possible.
What happens to slides that are classified ‘unqualified’ by the profiler system?
They will be re run if there is a full tray and the system integrity test has failed or no scanning data is available. The entire tray should be reloaded. If this happens frequently the system will stop.
They unqualified slides may be put through for process review. This will happen if a single slide with message comes up as unqualified or no scanning data is available. May need to improve the error and scan again. If this is not possible then slides will need to be screened visually. Slides may be classed as ‘unqualified’ due to too many bubbles, barcode not readable, slide tilted etc.
The number of slides put through for process review should be as low as possible.
