Comparative study of USPIO-enhanced and Gd-enhanced MRI in the diagnosis of atherosclerotic plaques in rabbits / 实用医学杂志

Objective To investigate the imaging characteristics of USPIO-enhanced and Gd-enhanced MRI in atherosclerosis and to compare the detection rate of atherosclerotic plaque between them. Methods Thirty-five healthy male rabbits were assigned to experimental group (n=30) to establish a model of atherosclerosis by damaging aortic tunica intima with Foley′s tube in combination with a high fat diet and 5 to control group without any intervention. At week 12, USPIO-enhanced and Gd-enhanced MRI scanning were conducted to compare the signal changes of atherosclerotic plaque before and after enhancement with the 2 contrast media. Ninety seven pictures were randomly selected respectively from the pictures enhanced by the 2 contrast media to compare the detection rate plaque between them. Pthology examination was used for detection standard. For the control group , pictures were randomly selected. Results In the experimental group, 7 rabbits died of Foley′s tube damaging, 2 died of raising and 1 died of anesthesia. All 5 rabbits in control group survived. A total of 172 pathological sections were made with 134 plaques and 72 vulnerable plaques pathologically confirmed. In pictures enhanced by USPIO , 84 plaques were confirmed by HE staining with a detection rate of 86.6%. In pictures enhanced by Gd, 72 plaques were confirmed by HE staining with a detection rate of 74.2%. Detection rate of USPIO-enhanced MRI in atherosclerosis plaque was significantly higher than that of Gd-enhanced MRI (X2=3.96, P=0.046). Conclusion USPIO shows its superiority as a new contrast medium in detection of atherosclerosis plaque.

Ultrasmall superparamagnetic iron oxide-enhanced magnetic resonance angiography combined with inflammatory factors for detecting atherosclerotic plaques in rabbits / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the feasibility of Ultrasmall superparamagnetic iron oxide-enhanced magnetic resonance angiography (USPIO-MRA) combined with interleukin-6 (IL-6) and IL-10 detection for detecting atherosclerotic plaques in rabbits.</p><p><b>METHODS</b>Twenty-four normal male rabbits were randomly assigned (n=8) into group A with atherosclerosis induced by damaging the aortic tunica intima with Foley's tube in combination with a high fat diet, group B with a high fat diet, and group C without any intervention. At week 12, plain and USPIO-MRA was performed in all the 24 rabbits and the results were compared with pathological examinations; blood samples were collected from the ear vein to examine blood lipids and levels of IL-6 and IL-10.</p><p><b>RESULTS</b>The rabbits in groups A and B showed significantly different IL-6 levels (167 ± 21.3 vs 116 ± 14.3 pg/ml, P<0.05) but comparable blood lipids and IL-10 levels (P>0.05). The levels of IL-6, IL-10, TC, TG, and LDL, but not HDL, differed significantly between groups A and C and between groups B and C (P<0.01). Continuous MRA scan showed significantly different signal-to-noise ratios (SNR) between the 3 groups.</p><p><b>CONCLUSION</b>USPIO-MRA combined with IL-6 and IL-10 detection is feasible in detecting atherosclerotic plaques in rabbits.</p>

Pump models assessed by transesophageal echocardiography during cardiopulmonary resuscitation / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>Transesophageal echocardiography was performed during closed-chest cardiopulmonary resuscitation (CPR) in in-hospital cardiac arrest to further explore the hemodynamic mechanism of CPR.</p><p><b>METHODS</b>CPR attempts were performed according to advanced cardiovascular life support guidelines in 6 cases of in-hospital cardiac arrest. Multi-plane transesophageal echocardiography was carried out within 15 min of initiation of CPR. Throughout CPR, the motion of the mitral, tricuspid and aortic valves, the changes in the left ventricular cavity size and the thoracic aortic diameter were observed. Trans-mitral and trans-aortic Doppler files of blood flow were also documented.</p><p><b>RESULTS</b>A closure of the mitral and tricuspid valves with simultaneous opening of the aortic valve occurred exclusively during chest compression, resulting in forward blood flow in the pulmonary and systemic circulation. Peak forward aortic flow at a velocity of 58.8 +/- 11.6 cm/s was recorded during the compression phase. Whereas, a closure of the aortic valve and rapid opening of the atrioventricular valves associated with ventricular filling during relaxation of chest compression was noted in all 6 patients. Peak forward mitral flow at a velocity of 60.6 +/- 20.0 cm/s was recorded during the release phase. Mitral regurgitation during the chest compression period was detected in 5 patients, reflecting a positive ventricular-to-atrial pressure gradient. A reduction in the left ventricular chamber and an increase in the thoracic aortic diameter during the compression phase was found in all patients, indicating that direct cardiac compression contributed to forward blood flow.</p><p><b>CONCLUSION</b>These observations favor the cardiac pump theory as the predominant hemodynamic mechanism of forward blood flow during CPR in human beings.</p>