To objectively and quantitatively study the effect of JPEG2000 lossy compression of nuclear medicine image, line source images of various noise levels, actual quadrant-bar phantom images and simulated quadrant-bar phantom images of various noise levels were compressed using a JPEG2000 plug-in at 10 : 1 to 50 : 1 with a 10 : 1 step. Modulation transfer function (MTF), full width at half-maximum (FWHM) and the peak to total count ratio (PTCR) of line spread function of the simulated line source images were analyzed quantitatively. Image quality of the quadrant-bar phantom images was visually evaluated according to quality control procedures and the result was used to verify the quantitative analysis. It was observed that PTCR decreased as compression ratio increased and the higher the noise level, the faster PTCR decreased, which was in accordance with the increase of the width of the smallest bars that can be visually resolved in the actual quadrant-bar phantom images and simulated quadrant-bar phantom images. On the other hand, no significant change of MTF and FWHM was observed as compression ratio increased. It was concluded that PTCR may serve as an objectively quantitative metrics of image quality assessment.
Algorithms ; Data Compression ; methods ; standards ; Diagnostic Imaging ; standards ; Humans ; Image Processing, Computer-Assisted ; Nuclear Medicine ; methods

To study the usefulness of JPEG2000 compression for nuclear medicine (NM) image, normal and abnormal static images were compressed using a JPEG2000 plug-in. For lossless algorithm, the compressing ratio (CR) was calculated. For lossy algorithm, images were visually analyzed by NM physicians and ROC curves were generated. The area under ROC curve (AUC) was used as the index of image diagnostic quality. Paired sample t tests were performed to compare the AUCs. It was found that the lossless CR was (1.34+/-0.05) : 1. For lossy algorithm, the AUC decreased with the increase of CR. Comparison between the original and the compressed images revealed no significant difference for 10:1 CR but significant difference for bigger CRs. It was concluded that lossless compression has little usefulness for NM image because of very low CR. While lossy compression isused, the diagnostic quality of static NM images is preserved at CRs 50 : 1,40 : 1, 30 : 1,20 : 1 up to 10 : 1. For other types of NM image, CR should be increased or decreased according to their characteristics, especially the level of intrinsic statistical noise of NM image.
Algorithms ; Area Under Curve ; Artifacts ; Data Compression ; methods ; standards ; Humans ; Image Processing, Computer-Assisted ; Nuclear Medicine ; methods ; Radionuclide Imaging ; Thyroid Gland ; diagnostic imaging

BACKGROUND: The use of mouse bone marrow mesenchymal stem cells (mBMSCs) represents a promising strategy for performing preclinical studies in the field of cell-based regenerative medicine; however, mBMSCs obtained via conventional isolation methods have two drawbacks, i.e., (i) they are heterogeneous due to frequent macrophage contamination, and (ii) they require long-term culturing for expansion. METHODS: In the present study, we report a novel strategy to generate highly pure mBMSCs using liposomal clodronate.This approach is based on the properties of the two cell populations, i.e., BMSCs (to adhere to the plasticware in culture dishes) and macrophages (to phagocytose liposomes). RESULTS: Liposomal clodronate added during the first passage of whole bone marrow culture was selectively engulfed by macrophages in the heterogeneous cell population, resulting in their effective elimination without affecting the MSCs.This method allowed the generation of numerous high-purity Sca-1 ＋ CD44 ＋ F4/80 - mBMSCs ([ 95%) with just one passaging. Comparative studies with mBMSCs obtained using conventional methods revealed that the mBMSCs obtained in the present study had remarkably improved experimental utilities, as demonstrated by in vitro multilineage differentiation and in vivo ectopic bone formation assays. CONCLUSION Our newly developed method, which enables the isolation of mBMSCs using simple and convenient protocol, will aid preclinical studies based on the use of MSCs.

Vibrio splendidus is an opportunistic pathogen in aquaculture. It can infect a variety of aquaculture animals and has caused huge losses to the aquaculture industry. In this study, a novel and efficient method for detecting V. splendidus was developed by combining the exonuclease Ⅲ amplification strategy with a nucleic acid test strip developed based on gold nanoparticles-labeled DNA probe. The results could be directly visualized by naked eyes, and this system overcame the difficulty in preparation of the monoclonal antibody used in conventional immunostrip. Upon optimization of experimental conditions, the detection limit of the strip was 5 ng/mL for the synthetic oligonucleotide DNA fragment and 10 ng/mL for the actual genomic DNA sample of V. splendidus. This test strip was more sensitive compared with the PCR method and was specific for the detection of V. splendidus. The rapid preparation of nucleic acid strip and the efficient detection of V. splendidus open a new way for the prevention and control of aquatic diseases.
Animals ; DNA Probes ; Gold ; Metal Nanoparticles ; Vibrio/genetics*