ObjectiveTo analyze the influencing factors for image quality of 18F-deoxyglucose (FDG) positron emission tomography (PET)/CT systemic tumor imaging and explore the method of control in order to improve the PET/CT image quality. MethodsRetrospective analysis of image data from March to June 2011 collected from 1 000 18F-FDG whole body tumor imaging patients was carried out. We separated standard films from non-standard films according to PET/CT image quality criteria. Related factors for non-standard films were analyzed to explore the entire process quality control. ResultsThere were 158 cases of standard films (15.80%), and 842 of non-standard films (84.20%). Artifact was a major factor for non-standard films (93.00%, 783/842) followed by patients’ injection information recording error (2.49%, 21/842), the instrument factor (1.90%, 16/842), incomplete scanning (0.95%, 8/842), muscle and soft tissue uptake (0.83%, 7/842), radionuclide contamination (0.59%, 5/842), and drug injection (0.24%, 2/842). The waste film rate was 5.80% (58/1 000), and the redoing rate was 2.20% (22/1 000). ConclusionComplex and diverse factors affect PET/CT image quality throughout the entire process, but most of them can be controlled if doctors, nurses and technicians coordinate and cooperate with each other. The rigorous routine quality control of equipment and maintenance, patients’ full preparation, appropriate position and scan field, proper parameter settings, and post-processing technology are important factors affecting the image quality.
In recent years, the incidence of thyroid cancer has been increasing. Researchers around the world have begun to pay more attention to the exploration of its pathogenesis, disease evolution and prognosis. Among them, research in the field of gene molecules has become a hotspot, which includes the mutations of v-raf murine sarcoma viral oncogene homologue B1 (BRAF) and the telomerase reverse transcriptase (TERT) promoter. However, this field is not mature, and there are many problems and challenges need to be solved. This paper explores the value of BRAF mutation in the treatment, recurrence, mortality and prognosis of papillary thyroid carcinoma. In addition, we also explore the relationship between BRAF mutation and TERT promoter mutations and their influences in thyroid cancer. We hope this paper could help later scholars understand the current situation in this field and find a research direction in the future.
Depression is a common psychiatric disorder, and approximately 30% patients with depression do not respond effectively to standard antidepressant medication; this condition is termed treatment resistant depression (TRD) and its neurobiological mechanism remains unclear. Neuroimaging techniques can non-invasively explore changes in brain structure, function and metabolism. These techniques have been applied in neurobiological research of TRD and revealed critical abnormalities in brain structure, function and metabolism in fronto-limbic system. In this paper, we reviewed the latest progress in neuroimaging researches on TRD, providing new insight and imaging evidence for further neurobiological studies of TRD.
ObjectiveTo improve health care quality and safety by monitoring the performance of PhilipsPrecedence Dual-head single photon emission computed tomography (SPECT). MethodsWith our own homemade point source and the center of rotation model, in accordance with NEMA standards and manufacturers' design conditions, these three indicators including energy peak position of the instrument, intrinsic uniformity and center of rotation were routinely tested between 2008 and 2012 for the Philips-Precedence Dual-head SPECT in our hospital. In addition, the quality control was performed twice a week, and every year the total number of quality control was basically the same. We calculated the results by the weighted average method. ResultsThe 5-year average energy peaks of detector 1 and 2 were (139.23±0.32) and (138.97±0.45) keV, respectively, and they were both within the range of reference values [(140±3) keV]. In addition, the results of center of rotation were also in the normal range, and kept stable. Based on the analysis of quality-control data, for detector 1, compared with the data of 2008, there was no significant diTherence for central field of vision (CFOV) and useful field of vision (UFOV) in these three years from 2009 to 2011 (P>0.05). The diTherence was only significant between data of 2008 and that of 2012 (P<0.05). For detector 2, compared with the data of 2008, there was no significant diTherence for CFOV and UFOV in 2009 and 2011(P>0.05), while there was significant diTherent in 2010 and 2012 (P<0.05). ConclusionThe uniformity of SPECT will gradually deteriorate with prolonged use. However, regular quality control and maintaining can keep the function stabilization, and enhance the availability rate.
ObjectiveTo investigate the effects of the operation of nuclear medicine technologists on the quality and efficiency of whole-body bone imaging with single-photon emission computed tomography (SPECT). MethodsWe collected all the data from patients who underwent whole-body bone imaging with SPECT in the whole year of 2012 in Department of Nuclear Medicine, West China Hopsital of Sichuan University.From January to June 2012, no intervention was made.Between July and December 2012, a formal training including vein puncture, image processing, and post image processing improving was made for the technologists on the operation of whole-body bone scan.The difference in incidence rate of artifacts between the first and second half of the year was analyzed by χ2 test. ResultsIn all the 12 424 whole-body bone scan patients, the first and second six months had respectively 5 920 and 7 186.And the artifacts incidence rates were 15.6% vs.8.9%(χ2=137.483, P < 0.001).In addition, the daywork efficiency was highly improved by 16.7%(48.5 patients/day vs.56.6 patients/day). ConclusionThe operation of the nuclear medicine technologists not only affects the quality of whole-body bone imaging but also improves the work efficiency.
This paper is aimed to assess the diagnostic value of MRI versus 99Tcm-methylene diphosphonate (99Tcm-MDP) bone scan (BS) for osseous metastases in patients with prostate cancer. The computer-based retrieval was conducted on PubMed, EMBASE, EBSCO, Web of Knowledge, the Cochrane Library and Ovid data bases to search for trials about diagnosing osseous metastases of prostate cancer with MRI and 99Tcm-MDP BS. Selected with time acceptance and time exclusion criteria, the data quality were evaluated with QUADAS quality assessment tool and collected. We used the Meta-Disc software to conduct meta-analysis, and then calculated the pooled sensitivity, specificity and diagnostic odds ratio (DOR), drew the summary receiving operating characteristic (SROC) curve, and measured the area under curve (AUC) and Q* value. Then five studies were included, involving 353 patients. The pooled sensitivity of MRI and BS was 0.95 (95% CI 0.90~0.98) and 0.67 (95% CI 0.58~0.75), respectively. The pooled specificity was 0.97 (95% CI 0.94~0.99) and 0.88 (95% CI 0.83~0.91), respectively. The pooled DOR was 402.99 (95% CI 119.05~1 364.15) and 23.85 (95% CI 1.32~431.48), respectively. The AUC was 0.990 1 and 0.624 1, respectively. The Q* was 0.958 7 and 0.593 8. It can well be concluded that MRI is more effective than 99Tcm-MDP BS in the diagnosis of osseous metastases in patients with prostate cancer.