Combining Coronary with Carotid and Cerebrovascular Angiography Using Prospective ECG Gating and Iterative Reconstruction with 256-slice CT.

OBJECTIVE: To investigate the image quality and radiation dose of combined coronary and carotid/cerebrovascular angiography with ECG gating and iterative reconstruction using 256-slice CT compared with the findings with the two examinations performed separately. PATIENTS AND METHODS: One hundred sixty-five consecutive patients underwent a single-injection single-pass combination of coronary and carotid/cerebrovascular CT angiography (group A), coronary CT angiography alone (group B), or carotid/cerebrovascular CT angiography alone (group C). We assessed the image quality of the combined and separate examinations and calculated the respective effective radiation doses. We evaluated the differences in the proportions of image quality grade between the combination and single-examination groups. Diagnostic performance of the combined scanning for detecting significant vascular stenosis has been compared with reference digital subtraction angiography (DSA) in the patient subgroup of group A. RESULTS: There was no significant difference in age, body mass index (BMI), or gender distribution among the 3 groups (all P > 0.05). But there was significant difference in scan length, DLP, and effective dose among the 3 groups (all P < 0.05). There were no significant differences in the effective radiation dose of coronary scanning between groups A and B (P > 0.05), while the effective radiation dose of carotid/cerebrovascular scanning in group A was significantly lower than that in group C (P < 0.05), and the total effective radiation dose in group A were relatively low (2.21 ± 1.38 mSv). The differences of the proportion of carotid/cerebrovascular image quality grades between groups A and C were not significant (P > 0.05). In a subgroup of group A of 30 patients with DSA, combined computed tomographic angiography successfully detected 56 coronary stenosis on per-segment basis, and 62 stenosis on carotid and cerebral artery. The sensitivity, specificity, positive and negative predictive value (NPV) of coronary stenosis were 91.80%, 95.60%, 87.50% and 97.21%, respectively. The sensitivity, specificity, positive and NPV of carotid/cerebrovascular stenosis were 93.55%, 94.68%, 92.06% and 95.70%, respectively. CONCLUSION: Combination of coronary and carotid/cerebrovascular angiography with 256-slice CT scanner with prospective ECG gating and iterative reconstruction produces diagnostic-quality images of the coronary, carotid, and cerebrovascular systems in a single examination, using less contrast medium and a lower radiation dose than when the two examinations are performed separately. This novel technique has high accuracy in detecting significant stenosis in one image setting.

Assessment of tumor vascularization with functional computed tomography perfusion imaging in patients with cirrhotic liver disease.

BACKGROUND: Hepatocellular carcinoma (HCC) is a common malignant tumor in China, and early diagnosis is critical for patient outcome. In patients with HCC, it is mostly based on liver cirrhosis, developing from benign regenerative nodules and dysplastic nodules to HCC lesions, and a better understanding of its vascular supply and the hemodynamic changes may lead to early tumor detection. Angiogenesis is essential for the growth of primary and metastatic tumors due to changes in vascular perfusion, blood volume and permeability. These hemodynamic and physiological properties can be measured serially using functional computed tomography perfusion (CTP) imaging and can be used to assess the growth of HCC. This study aimed to clarify the physiological characteristics of tumor angiogenesis in cirrhotic liver disease by this fast imaging method. METHODS: CTP was performed in 30 volunteers without liver disease (control subjects) and 49 patients with liver disease (experimental subjects: 27 with HCC and 22 with cirrhosis). All subjects were also evaluated by physical examination, laboratory screening and Doppler ultrasonography of the liver. The diagnosis of HCC was made according to the EASL criteria. All patients underwent contrast-enhanced ultrasonography, pre- and post-contrast triple-phase CT and CTP study. A mathematical deconvolution model was applied to provide hepatic blood flow (HBF), hepatic blood volume (HBV), mean transit time (MTT), permeability of capillary vessel surface (PS), hepatic arterial index (HAI), hepatic arterial perfusion (HAP) and hepatic portal perfusion (HPP) data. The Mann-Whitney U test was used to determine differences in perfusion parameters between the background cirrhotic liver parenchyma and HCC and between the cirrhotic liver parenchyma with HCC and that without HCC. RESULTS: In normal liver, the HAP/HVP ratio was about 1/4. HCC had significantly higher HAP and HAI and lower HPP than background liver parenchyma adjacent to the HCC. The value of HBF at the tumor rim was significantly higher than that in the controls. HBF, HBV, HAI, HAP and HPP, but not MTT and PS, were significantly higher in the cirrhotic liver parenchyma involved with HCC than those of the controls. Perfusion parameters were not significantly different between the controls and the cirrhotic liver parenchyma not involved with HCC. CONCLUSIONS: CTP can clearly distinguish tumor from cirrhotic liver parenchyma and controls and can provide quantitative information about tumor-related angiogenesis, which can be used to assess tumor vascularization in cirrhotic liver disease.

A Guideline-Based Decision Tree Achieves Better Glucose Control with Less Hypoglycemia at 3 Months in Chinese Diabetic Patients.

INTRODUCTION: China has the world's largest diabetes epidemic and has been facing a serious shortage of primary care providers for chronic diseases including diabetes. To help primary care physicians follow guidelines and mitigate the workload in primary care communities in China, we developed a guideline-based decision tree. This study aimed to validate it at 3 months with real-world data. METHODS: The decision tree was developed based on the 2017 Chinese Type 2 Diabetes (T2DM) guideline and 2018 guideline for primary care. It was validated with the data from two registry studies: the NEW2D and ORBIT studies. Patients' data were divided into two groups: the compliance and non-compliance group, depending on whether the physician's prescription was consistent with the decision tree or not. The primary outcome was the difference of change in HbA1c from baseline to 3 months between the two groups. The secondary outcomes included the difference in the proportion of patients achieving HbA1c < 7% at 3 months between the two groups, the incidence of self-reported hypoglycemia at 3 months, and the proportion of patients (baseline HbA1c ≥ 7%) with a HbA1c reduction ≥ 0.3%. The statistical analysis was performed using linear or logistic regression with inverse probability of treatment weighting with adjustments of confounding factors. RESULTS: There was a 0.9% reduction of HbA1c in the compliance group and a 0.8% reduction in the non-compliance group (P < 0.001); 61.1% of the participants in the compliance group and 44.3% of the participants in the non-compliance group achieved a HbA1c level < 7% at 3 months (P < 0.001). The hypoglycemic events occurred in 7.1% of patients in the compliance group vs. 9.4% in the non-compliance group (P < 0.001). CONCLUSION: The decision tree can help physicians to treat their patients so that they achieve their glycemic targets with fewer hypoglycemic risks. ( http://www.clinicaltrials.gov NCT01525693 & NCT01859598).

Integrating Clinical Knowledge and Real-World Evidence for Type 2 Diabetes Treatment.

Clinical decision support system (CDSS) plays a significant role nowadays and it assists physicians in making decisions for treatment. Generally based on clinical guideline, the principles of the recommendation are provided and may suggest several candidate medications for similar patient group with certain clinical conditions. However, it is challenging to prioritize these candidates and even refine the guideline to a finer level for patient-specific recommendation. Here we propose a method and system to integrate the clinical knowledge and real-world evidence (RWE) for type 2 diabetes treatment, to enable both standardized and personalized medication recommendation. The RWE is generated by medication effectiveness analysis and subgroup analysis. The knowledge model has been verified by clinical experts from the advanced hospitals. The data verification results show that the medications that are consistent with the method recommendation can lead to better clinical outcome in terms of glycemic control, compared to those inconsistent.

Investigation on the optical scan condition for imaging of multi-slice spiral CT liver perfusion in rats.

BACKGROUND: Multi-slice CT liver perfusion has been widely used in experimental studies of hemodynamic changes in liver lesions, and is usually performed as an adjunct to a conventional CT examination because of its high temporal and spatial resolution, simple protocol, good reproducibility, and ability to measure hemodynamic changes of liver tissues at the capillary level. Experimental rat models, especially those of induced liver cancer, are often used in studies of hemodynamic changes in liver cancer. Carcinogenesis in rats has a similar pathological progression and characteristics resembling those in human liver cancer; as a result, rat models are often used as ideal animal models in the study of human liver cancer. However, liver perfusion imaging in rats is difficult to perform, because rats' livers are so small that different concentrations, flow rates, and dose of contrast agents during the CT perfusion scanning can influence the quality of liver perfusion images in rats. The purpose of this study, therefore, was to investigate the optimal scan protocol for the imaging of hepatic perfusion using a deconvolution mathematical method in rats by comparing the results of rats in different injection conditions of the contrast agent, including concentration, rate and time. METHODS: Plain CT scan conditions in eighty 2-month-old male Wistar rats were 5.0 mm slice thickness, 5.0 mm interval, 1.0 pitch, 120 kV tube voltage, 60 mA tube current, 512 × 512 matrix, and FOV 9.6 cm. Perfusion scanning was carried out with different concentrations of diatrizoate (19%, 38%, 57%, and 76%), different injection rates (0.3 and 0.5 ml/s), and different injection times (1, 2-3, 4-5, and 6 seconds). The above conditions were randomly matched and adjusted to determine the best perfusion scan protocol. Three-phase contrast-enhanced scanning was performed after CT perfusion. Histological examination of the liver tissues with hematoxylin and eosin stains was done after CT scanning. RESULTS: When the concentration of the contrast agent was 19% or 38%, no pseudo-color map was created. The viscosity increased when the concentration of the contrast agent was 76%; so it is difficult to inject the contrast agent at such a high concentration. Also no pseudo-color map was generated when the injection time was short (1, 2-3, and 4-5 seconds) or the injection rate was low (0.3 ml/s). The best perfusion images and perfusion parameters were obtained during 50 seconds scanning. Each rat was given an injection of 57% diatrizoate at 0.5 ml/s via the tail vein using a high-pressure syringe for 6 seconds. The perfusion parameters included hepatic blood flow (HBF), hepatic blood volume (HBV), mean transit time (MTT) of the contrast agent, capillary permeability-surface area product (PS), hepatic arterial index (HAI), hepatic artery perfusion (HAP), and hepatic portal perfusion (HPP). All these parameters reflected the perfusion status of liver parenchyma in normal rats. Three phases of enhancement were modified according to the time-density curves (TDCs) of the perfusion imaging: hepatic arterial phase (7 seconds), hepatic portal venous phase (15 seconds), and a delayed phase (23-31 seconds). On examination by microscopy, the liver tissues were pathologically normal. CONCLUSIONS: The appropriate protocol with multi-slice spiral CT liver perfusion reflected normal liver hemodynamics in rats. This study laid a solid foundation for further investigation of the physiological characteristics of liver cancer in a rat model, and was an important supplement to and reference for conventional contrast-enhanced CT scans.