PET/CT is a new imaging technology that combines high-quality Positron Emission Tomography (PET) and Computed Tomography (CT). This imaging provides simultaneous anatomical and metabolic information. Therefore PET/CT is useful diagnostic modality for early detection of malignant tumor, accurate staging, decision on therapeutic plan, monitoring response to therapy and rapid detection of recurrence. We report oral and maxillofacial cancers diagnosed by using PET/CT and the usefulness of PET/CT in the evaluation of postoperative recurrence.
Mouth Neoplasms* ; Positron-Emission Tomography ; Positron-Emission Tomography and Computed Tomography* ; Recurrence ; Tomography, X-Ray Computed

In this study, through the analysis of the composition of domestic large radioactive medical equipment PET/CT and the characteristics of each subsystem, combing the vulnerable spots, according to the standard requirements of PET/CT for 10 years in its service life, we research the PET/CT service life's effectiveness. Firstly, this study introduces the concept of service life, the relationship between service life and risk analysis, the pivotal system composition of PET/CT, the importance of reliability of each component, the traditional test method to verify its reliability is researched. This study suggests a test procedure and method to prove the reliability of various components of PET/CT equipment during the service life. This method is described in detail, and the specific test process in practical engineering application is discussed, which proves that it is beneficial to ensure the effectiveness of PET/CT during the service life.
Positron Emission Tomography Computed Tomography ; Positron-Emission Tomography ; Reproducibility of Results ; Tomography, X-Ray Computed

PET/CT imaging can reflect the physiological metabolic process in living body which is the model experiment incapable to simulate. Animal experiment may be considered for systematic validation of PET/CT products. The obtained research data can be used to evaluate the feasibility, effectiveness and safety of PET/CT products, and be submitted as supporting documents for research data or clinical evaluation data when doing product registration or alteration registration. In this study, the functions and advantages of animal experiments were expounded, and relevant research cases were given as well as the issues that should be paid attention to. It can be a reference for the validation and review of PET/CT products.
Animal Experimentation ; Animals ; Positron Emission Tomography Computed Tomography ; Positron-Emission Tomography ; Tomography, X-Ray Computed

Adrenal incidentalomas are adrenal masses serendipitously detected during an imaging study performed for reasons unrelated to suspicion of adrenal disease. The incidence of adrenal incidentalomas has increased because of the widespread use of various imaging modalities. In oncology patients with adrenal incidentalomas, the characterization of the adrenal masses is challenging because nearly 50% of incidental adrenal masses are metastatic lesions that need special medical attention. Although unenhanced computed tomography (CT) densitometry, chemical shift magnetic resonance imaging (MRI), delayed contrast-enhanced CT and CT histogram analysis have been used as sensitive and specific modalities for differentiating benign from malignant adrenal masses, F-18 fluoro-2-deoxy-D-glucose positron emission tomography (F-18 FDG PET)/CT is a highly accurate imaging modality compared to CT or MRI, especially when these two imaging modalities are combined. In addition, a semiquantitative analysis using standardized uptake value ratio further improves the diagnostic accuracy of F-18 FDG PET/CT in differentiating benign from malignant adrenal masses. Thus, F-18 FDG PET/CT is very helpful for determining the best therapeutic management, especially for assessing the need for surgery.
Densitometry ; Diagnosis, Differential* ; Electrons* ; Fluorodeoxyglucose F18 ; Humans ; Incidence ; Magnetic Resonance Imaging ; Multidetector Computed Tomography ; Positron-Emission Tomography ; Positron-Emission Tomography and Computed Tomography ; Tomography, X-Ray Computed

With the development of molecular imaging technology, incorporate multiple modes of medical imaging imaging techniques of SPECT/CT and PET/CT technology with a certain degree of development. But compared to SPECT/CT and PET/CT technologies, SPECT/CT far earlier than PET/CT technology to clinical applications, due to a variety of factors influence SPECT/CT far PET/CT clinical applications to grow faster. This article highlights the progress and problems of SPECT/CT technology.
Diagnostic Imaging ; Positron-Emission Tomography ; Tomography, Emission-Computed, Single-Photon ; Tomography, X-Ray Computed

Conventional biomedical imaging modalities in wide clinical use, such as ultrasound imaging, X-ray computed tomography, magnetic resonance imaging, and positron emission tomography, can provide morphological, anatomical, and functional information about biological tissues. However, single mode imaging in conventional medicine provides only limited information for definitive diagnoses. Thus, combinational diagnosis using multiple imaging modalities has become increasingly important. Recently, photoacoustic imaging (PAI) has gained significant attention, and several PAI prototypes have been used in clinical trials. At the same time, PAI has been tested in combination with conventional imaging modalities. For all these imaging modalities, various contrast-enhancing agents have been developed for various purposes. In this review article, we will focus on recent progress in developing dual mode contrast agents for PAI in combination with other conventional imaging modalities.
Contrast Media ; Diagnosis ; Magnetic Resonance Imaging ; Positron-Emission Tomography ; Tomography, X-Ray Computed ; Ultrasonography

OBJECTIVE: To investigate the imaging characteristics of F-FDG positron emission computed tomography (F-FDG PET/CT) in multiple myeloma (MM) patients and to analyze its application value in MM and bone metastases. METHODS: A retrospective analysis was made on MM patients (n=72) and bone metastases patients (n=50) admitted to Hainan Western Central Hospital from January 2017 to March 2019. All patients underwent F-FDG PET/CT examination. The distribution of lesions, bone destruction, maximum standardized uptake (SUV) and metabolic homogeneity were analyzed in both groups. RESULTS: More than 80% of MM and bone metastases involved thoracic bone, spine and pelvis, followed by limbs. MM was more common in the lesions of thoracic bone and skull than those in bone metastases, the difference was statistically significant (P＜0.05). The majority of MM patients presented osteolytic bone destruction (97.2%), mostly showing "insect-like phagocytic pattern", so the bone showed dilated changes, and osteogenic changes were rarely seen (2.8%). Osteolytic bone destruction accounted for 74.0% in patients with bone metastatic tumor, presenting "focal" appearance more often, and osteogenic changes accounted for 26.0%. Osteolytic bone destruction in patients with MM was significantly higher than that in patients with bone metastases（χ=14.757，P＜0.05）. The SUV of MM (4.25±2.16)was significantly lower than that of bone metastases (7.84±3.25) (t=6.830, P＜0.05). Diffuse mild uptake of F-FDG was more common in patients with MM, and heterogeneous high uptake of F-FDG was more common in patients with bone metastasis, the difference was statistically significant (P＜0.05). CONCLUSION F-FDG PET/CT examination is helpful to acquire the imaging features of bone structure and metabolic changes, and shows an important clinical value in the differential diagnosis of MM and bone metastases.
Fluorodeoxyglucose F18 ; Humans ; Multiple Myeloma ; Positron Emission Tomography Computed Tomography ; Positron-Emission Tomography ; Radiopharmaceuticals ; Retrospective Studies ; Tomography, X-Ray Computed

Compared with conventional imaging, 18F-fluorodeoxyglucose positron-emission tomography compared with computed tomography (18F-FDG PET/CT) possesses higher sensitivity and specificity in the diagnosis of solitary pulmonary nodule (SPN) and lung cancer. From the perspective of health economics, PET/CT is more suitable strategy for diagnose of SPN with intermediate probability of malignancy, and has good health economics value in preoperative staging diagnosis and follow-up after radiotherapy and chemotherapy of lung cancer. The evaluation method, effect index and comparison method used in the health economics research of PET/CT for lung cancer diagnosis and treatment are cost-effect analysis, life year and incremental cost-effect ratio, respectively. Case tracking and follow-up was a means of early studies on PET/CT health economics, and in recent years mathematical models are used in most studies.
Fluorodeoxyglucose F18 ; Humans ; Lung Neoplasms ; Neoplasm Staging ; Positron Emission Tomography Computed Tomography ; Positron-Emission Tomography ; Radiopharmaceuticals ; Tomography, X-Ray Computed

The current PET/CT system with high quality CT images not only increases diagnostic value by providing anatomic localization, but also shortens the acquisition time for attenuation correction than primary PET system. All commercially available PET/CT system uses the CT scan for attenuation correction instead of the transmission scan using radioactive source such as 137Cs, 68Ge. However the CT scan may substantially increase the patient dose. The purpose of this study was to evaluate quality of PET images reconstructed by CT attenuation map using various tube currents. In this study, images were acquired for 3D Hoffman brain phantom and cylindrical phantom using GE DSTe PET/CT system. The emission data were acquired for 10 min using phantoms after injecting 44.03 MBq of 18F-FDG. The CT images for attenuation map were acquired by changing tube current from 10 mA to 95 mA with fixed exposure time of 8 sec and fixed tube voltage of 140 kVp. The PET images were reconstructed using these CT attenuation maps. Image quality of CT images was evaluated by measuring SD (standard deviation) of cylindrical phantom which was filled with water and 18F-FDG solution. The PET images were evaluated by measuring the activity ratio between gray matter and white matter in Hoffman phantom images. SDs of CT images decrease by increasing tube current. When PET images were reconstructed using CT attenuation maps with various tube currents, the activity ratios between gray matter and white matter of PET images were almost same. These results indicated that the quality of the PET images using low dose CT data were comparable to the PET images using general dose CT data. Therefore, the use of low dose CT is recommended than the use of general dose CT, when the diagnostic high quality CT is not required. Further studies may need to be performed for other system, since this study is limited to the GE DSTe system used in this study.
Brain ; Fluorodeoxyglucose F18 ; Humans ; Positron-Emission Tomography and Computed Tomography* ; Tomography, X-Ray Computed ; Water

Experiments and simulation were done to study the impact of contrast agent when CT scan was used to attenuation correction for PET images in PET/CT system. Whole body phantom was imaged with various concentration of iodine-based contrast agent using CT. Mathematical emission and transmission density map with liver were made to simulate for whole body FDG imaging. A variety of factors were estimated, including non-uniform enhancement of contrast agent, concentration and distribution size of contrast agent, noise level, image resolution, reconstruction algorithm, hypo-attenuation of contrast agent, and different time phases for contrast agent. Experimental studies showed that Hounsfield unit depends on the concentration of contrast agent and tube voltage. From the simulation data, contrast agents introduced artifacts and degraded image quality on the attenuation-corrected PET images. The severity of these effects depends on a variety of factors, including the concentration and distribution size of contrast agent, the noise levels, and the image resolution. These results indicated that the impact of contrast agents should be considered with a full understanding of their potential problems in clinical PET/CT images.
Artifacts ; Contrast Media ; Liver ; Noise ; Positron-Emission Tomography and Computed Tomography ; Tomography, X-Ray Computed