Use of Virtual Microscopy for the Examination of Peripheral Blood Smears at Remote Locations
Juan Gomez-Gelvez, Devon Chabot, Javier Arias-Stella, Kathryn Foucar, Kedar Inamdar, Kristin Karner. Henry Ford Hospital, Detroit, MI; University of New Mexico, Albuquerque, NM
Background: Evaluation of the peripheral blood smear (PBS) is still essential in current medical practice. The introduction of virtual microscopy (VM) has enabled the interpretation of PBS at remote locations. In this study we aimed to validate the use of VM for the evaluation of PBS as an option to provide expert interpretation to remote sites.
Design: We selected 20 PBS representing normal and abnormal findings seen at a community-based hospital. Two hematopathologists evaluated each case using conventional light microscopy (LM) and VM by an Aperio ScanScope and ImageScope software (Aperio, Vista, CA). Reviewers (RV) were provided the patient's age, sex, brief clinical history and CBC data. Each RV performed manual differential, quantitative interpretation and morphologic evaluation of white blood cells (WBC), red blood cells (RBC), and platelets (PLT). RBC findings were graded as 0, 1+ or 2+, depending on percentage of abnormal cells. For the morphologic evaluation of WBC and PLT, all findings were registered as either present or absent. Final diagnoses were written in a free text format and compared for major (e.g. differences in the main findings) and minor (e.g. differences in the interpretation of the possible etiology of the main findings) inter- and intraobserver discrepancies.
Results: On average for the two RV, differences of >15% in the differential count was seen in 3/20 (15%) of cases for neutrophils, in 2/20 (10%) for lymphocytes and 0.5/20 (2.5%) for monocytes. None of the 20 cases showed relevant differences in RBC, WBC and PLT morphology. Comparison of final diagnoses between VM and LM showed minor discrepancies in 2.5/20 (12.5%) of the cases on average for the two RV. Interobserver comparison of LM showed minor discrepancies in 4/20 (20%) of the cases and major discrepancies in 1/20 (5%). Interobserver comparison of VM showed minor discrepancies in 1/20 (5%) of the cases and major discrepancies in 1/20 (5%), same case as in LM. Major discrepancy was due to the failure to identify a scant amount of blast cells by one of the reviewers. Reviewers agreed upon the limited analysis of intracellular inclusions, parasites and specific morphologic features.
Conclusions: VM is a useful tool in the triage of urgent specimens as an option to obtain expert interpretation in locations where experienced staff is not available on site. RBC, WBC and PLT morphology can be reliably identified. VM would be less useful for the identification of intracellular parasites and other inclusions.
Wednesday, March 6, 2013 9:30 AM
Poster Session V # 285, Wednesday Morning