Rapid on-site assessment of specimens by biomedical scientists improves the quality of head and neck fine needle aspiration cytology.

OBJECTIVE: Immediate rapid on-site assessment (ROSA) of fine needle aspiration cytology (FNAC) specimens by biomedical scientists (BMS), the UK equivalent of cytotechnologists, or by pathologists may improve specimen quality and cellular adequacy rates for lymph node, head and neck and thyroid FNAC. The aim of this study was to evaluate the effect of introducing ROSA by BMS in an outpatient clinic setting. METHODS: The adequacy rate and sensitivity of histological diagnosis for lymph node, thyroid and salivary gland FNAC samples were determined before and after the introduction of BMS ROSA. The additional financial costs and time required to perform this service were also estimated. RESULTS: Thirty-one patients underwent ultrasound (US)-guided FNAC with ROSA and 151 without. ROSA reduced the number of FNAC insufficient in quality for diagnosis from 43% to 19% (P = 0.0194). The estimated additional cost for pathology per patient for ROSA was between £52.05 and £70.74, equivalent to €65.40/US $83.90 and €88.89/US $114.0, respectively, an increase of between 28% and 49% from the original cost. ROSA necessitated an additional 6 minutes clinic time per patient, reducing the number of patients that could be seen in an average clinic from 13 to 10 as well as requiring increased laboratory time for FNAC slide assessment. CONCLUSION: ROSA by suitably trained biomedical scientists and with appropriate consultant pathologist support can improve the quality of FNAC sampling for head and neck lesions. Although ROSA resulted in both additional financial and time costs, these are more than likely to be offset by a reduction in patients returning to clinic for repeat FNAC or undergoing unnecessary surgery.

A registration and interpolation procedure for subvoxel matching of serially acquired MR images.

OBJECTIVE: Methods for automatically registering and reslicing MR images using an interpolation function that matches the structure of the image data are described. MATERIALS AND METHODS: Phantom and human brain images were matched by rigid body rotations and translations in two and three dimensions using a least-squares optimization procedure. Subvoxel image shifts were produced with linear or sinc interpolation. RESULTS: The use of sinc interpolation ensured that the repositioned images were faithful to the original data and enabled quantitative intensity comparisons to be made. In humans, image segmentation was vital to avoid extraneous soft tissue changes producing systematic errors in registration. CONCLUSIONS: The sinc-based interpolation technique enabled serially acquired MR images to be positionally matched to subvoxel accuracy so that small changes in the brain could be distinguished from effects due to misregistration.