الملخص
Radionuclide hypoxia imaging has become an indispensable core of tumor diagnosis. Nitroimidazole derivatives have been extensively used as the hypoxia imaging agents in preclinical and clinical research. It is the key to design the ideal structure for promising agents. The type and quantity of nitroimidazole, the linker structure and chiral may have an impact on the imaging results. The characteristics of the imaging agents including single electron reduction potential (SERP), oil-water partition coefficient (log P) and pharmacokinetics are also the key factors. In this review, we highlight the factors for hypoxia imaging, providing clues for the structure design of new agents.
الملخص
Objective To stratify the risks of patients with acute pulmonary embolism (APE) and pulmonary hypertension (PH) by dynamic pulmonary perfusion imaging (DPPI) and pulmonary perfusion imaging (PPI). Methods From October 2007 to February 2009, 20 healthy volunteers ( 12 males, 8 females; mean age =48.47 ±13.47 years) and 31 APE patients (21 males, 10 females; mean age =47.68 ±18.06 years; from October 2007 to July 2009) were included in the study. DPPI and PPI were performed in all subjects. Percentage of perfusion defect scores ( PPDs% ) were calculated by semi-quantitative analysis of PPI. Risk levels were defined according to PPDs% calculated from PPI: normal (PPDs% =0); very low risk (0 < PPDs% ≤10% ); low risk (10% < PPDs% ≤20% ); moderate risk (20% < PPDs% ≤40% );high risk (40% < PPDs% ≤60% ) and very high risk ( PPDs% > 60% ). Lung equilibrium time (LET)was calculated on region of interest (ROI) drawn over DPPI. Clinical risk was scored by Aujesky method.The t-test, ANOVA and correlation analysis were used with SPSS 13.0 software. Results ( 1 ) LET in healthy volunteers and APE patients was ( 12.18 ± 3.28) and (32.90 ± 14.29) s respectively (t = 6. 81,P < 0. 01 ). (2) The correlation coefficient, coefficient of determination between LET and PPDs% in APE patients were 0.93 and 0. 87, respectively. The correlation coefficient between LET and clinical risk score was 0.86. (3)The mean LET of APE patients in very low risk (n =5), low risk (n = 12), moderate risk (n=9), high risk (n=4) and very high risk groups (n=1) were (19.59 ±0.04), (25.03 ±0.08),(36.07 ±0. 10), (57.15 ±0.06) and (70 ±0.00) s, respectively. There was significant difference among APE patients with different risk levels (F =16. 78, P <0.01). Conclusions ( 1 ) DPPI was a reliable, convenient and non-invasive method for the evaluation of PH in APE. (2) Combined LET of DPPI and PPDs% of PPI was valuable for risk stratification and prognosis estimation in APE patients.
الملخص
Objective To study the correlation between bone marrow edema (BME), the amount of joint fluid and clinical symptoms in order to strengthen further understandings about clinical significance of BME in osteonecrosis of the femoral head (ONFH). Methods Fifty-seven patients (91 hips) with ONFH proved by clinical follow-up or pathology were examined by conventional radiography, 1.5 T MRI, and radionuclide imaging. BME, necrotic area, and joint fluid were analyzed respectively in ONFH with pre- or post-collapse of the femoral head and different MR signal intensities within necrotic area.Results ①The characteristic “line-like sign” appeared on MRI in 88 of 91 affected hips, and BME was seen in the distal zone away from line(s) in 61 hips, extending to the femoral neck and intertrochanteric region. ②The ratio of the occurance of BME in the collapse was greater than that in noncollapse, and in mixed signals within necrotic area without collapse greater than pure fat-like signal (P0.05), and both were greater than noncollapse without BME (P