The traditional SPECT has been considered unable to quantitatively analyze due to the limitations of device performance and reconstructing algorithm. Because of the development of SPECT devices, the emergence of SPECT/CT, and the improvement of reconstructive algorithms, SPECT can be used for quantitative analysis like PET. The current quantitative SPECT researches focus on the usefulness of quantitative SPECT technology in clinical diagnosis and the guidance and evaluation of radionuclide therapy. This review summarizes the development of SPECT quantification, the current status of quantitative SPECT researches in clinical diagnosis and radionuclide therapy, as well as the limitations and advantages of SPECT quantification.

ObjectiveTo explore the mechanism of Yishen Huashi granules in alleviating renal tubular epithelial cell injury and relieving diabetic kidney disease by regulating the mitogen-activated protein kinase （MAPK） signaling pathway. MethodsThe db/db mice of 12 weeks old were randomly assigned into model ， dapagliflozin （1.6 mg·kg^-1）， and Yishen Huashi granules （4.7 g·kg^-1）， and db/m mice were used as the control group. The general conditions of mice were observed， and fasting blood glucose and 24-h urinary protein and albumin-to-creatinine ratio （ACR） were measured at weeks 0 and 12 of administration. After 12 weeks of treatment， the levels of serum creatinine （SCr）， blood urea （UREA）， triglycerides （TG）， total cholesterol （TC）， and low density lipoprotein （LDL） were measured. The pathological changes in the renal tissue were observed by hematoxylin-eosin （HE） staining， Periodic acid-Schiff （PAS） staining， Mallory staining， and transmission electron microscopy. Real-time PCR was employed to determine the mRNA levels of monocyte chemotactic protein-1 （MCP-1） and CC chemokine receptor-2 （CCR2） in the renal tissue of mice. The immunohistochemical assay was employed to examine the expression of p38， phospho-p38 （p-p38）， MCP-1， and CCR2 in the renal tissue of mice. Western blotting was employed to measure the protein levels of p-p38， p38， MCP-1， and CCR2 in the renal tissue of mice.HK-2 cells cultured in vitro were grouped as follows： negative control， high glucose（30 mmol·L^-1）， Yishen Huashi granule-containing serum， and SB203580. After 48 h of cell culture in each group， RNA were extracted and the levels of MCP-1， and CCR2 mRNA were determined by Real-time PCR，proteins were extracted and the levels of p38， p-p38， MCP-1， and CCR2 were determined by Western blot. ResultsThe in vivo experiments showed that before treatment， other groups had higher body weight， blood glucose level， 24 h urinary protein， and ACR than the control group （P<0.05，P<0.01）. After 12 weeks of treatment， compared with the model group， the Yishen Huashi granules group showed improved general conditions， a decreasing trend in body weight， lowered levels of blood glucose， 24-h urinary protein， and ACR （P<0.01）， reduced SCr and UREA （P<0.01）， and declined levels of TC， TG， and LDL （P<0.05，P<0.01）. Compared with the model group， the Yishen Huashi granules group showed alleviated damage and interstitial fibrosis in the renal tissue as well as reductions in glomerular foot process fusion and basement membrane thickening. Moreover， the Yishen Huashi granules group showed down-regulated mRNA levels of MCP-1 and CCR2 （P<0.01）， reduced positive expression of p-p38， MCP-1， and CCR2 （P<0.01）， and down-regulated protein levels of p-p38/p38， MCP-1， and CCR2 （P<0.05） in the renal tissue. The cell experiment showed that compared with the high glucose group， the Yishen Huashi granule-containing serum group showcased down-regulated mRNA levels of MCP-1 and CCR2 （P<0.01） and down-regulated protein levels of p-p38/p38， MCP-1， and CCR2（P<0.05，P<0.01）. ConclusionYishen Huashi granules can regulate glucose-lipid metabolism， reduce 24 h urinary protein and ACR， improve the renal function， alleviate the renal tubule injury caused by high glucose， and protect renal tubule epithelial cells in db/db mice by reducing MCP-1/CCR2 activation via the p38 MAPK signaling pathway.