Comparison of Positron Emission Tomography Using 2-18F-fluoro-2-deoxy-D-glucose and 3-deoxy-3-18F-fluorothymidine in Lung Cancer Imaging / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The detection of solitary pulmonary nodules (SPNs) that may potentially develop into a malignant lesion is essential for early clinical interventions. However, grading classification based on computed tomography (CT) imaging results remains a significant challenge. The 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)/CT imaging produces both false-positive and false-negative findings for the diagnosis of SPNs. In this study, we compared 18F-FDG and 3-deoxy-3-[18F]-fluorothymidine (18F-FLT) in lung cancer PET/CT imaging.</p><p><b>METHODS</b>The binding ratios of the two tracers to A549 lung cancer cells were calculated. The mouse lung cancer model was established (n = 12), and micro-PET/CT analysis using the two tracers was performed. Images using the two tracers were collected from 55 lung cancer patients with SPNs. The correlation among the cell-tracer binding ratios, standardized uptake values (SUVs), and Ki-67 proliferation marker expression were investigated.</p><p><b>RESULTS</b>The cell-tracer binding ratio for the A549 cells using the 18F-FDG was greater than the ratio using 18F-FLT (P < 0.05). The Ki-67 expression showed a significant positive correlation with the 18F-FLT binding ratio (r = 0.824, P< 0.01). The tumor-to-nontumor uptake ratio of 18F-FDG imaging in xenografts was higher than that of 18F-FLT imaging. The diagnostic sensitivity, specificity, and the accuracy of 18F-FDG for lung cancer were 89%, 67%, and 73%, respectively. Moreover, the diagnostic sensitivity, specificity, and the accuracy of 18F-FLT for lung cancer were 71%, 79%, and 76%, respectively. There was an obvious positive correlation between the lung cancer Ki-67 expression and the mean maximum SUV of 18F-FDG and 18F-FLT (r = 0.658, P< 0.05 and r = 0.724, P< 0.01, respectively).</p><p><b>CONCLUSIONS</b>The 18F-FDG uptake ratio is higher than that of 18F-FLT in A549 cells at the cellular level. 18F-FLT imaging might be superior for the quantitative diagnosis of lung tumor tissue and could distinguish lung cancer nodules from other SPNs.</p>

Combination of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography and magnetic resonance imaging is an optimal way to evaluate rheumatoid arthritisin rats dynamically / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Rheumatoid arthritis (RA) is a chronic, systemic autoimmune inflammatory disorder. Many methods have been used to observe the progress of RA. The purpose of this study was to observe the progress of RA in rats with 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), magnetic resonance (MR) imaging and arthritis score, and analyze the relationships among different methods in evaluation of RA.</p><p><b>METHODS</b>Sixteen healthy Sprague Dawley (SD) rats about 8-week old were randomly assigned to a RA group and a control group. Bovine type II emulsified incomplete Freud's adjuvant was used to induce arthritis in the RA group. Arthritis score of the rats in two groups were recorded, and (18)F-FDG PET/CT, MR imaging were performed both on the corresponding rats every 3 days. All the rats were sacrificed at week 5, and histopathological examination was performed on rat knees stained with haematoxylin and eosin.</p><p><b>RESULTS</b>The arthritis score and the standard uptake value (SUV) of knee joints in RA rats increased with the progression of arthritis gradually. Both peaks of arthritis score and SUV appeared at 21 days after the first immune injection, then the arthritis score and SUV of knee joints decreased slowly. The arthritis scores of knee joints in RA rats were positively correlated with their SUV changes. The MR images were confirmed by the histopathological studies.</p><p><b>CONCLUSION</b>PET/CT can detect the earliest molecular metabolism changes of RA, and MR imaging can follow up the dynamical anatomical changes of RA, all of which indicated that PET/CT and MR imaging may be applied as useful tools to monitor the progress of RA.</p>

Quantitative T2 mapping evaluation for articular cartilage lesions in a rabbit model of anterior cruciate ligament transection osteoarthritis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Quantitative T2 mapping has been a widely used method for the evaluation of pathological cartilage properties, and the histological assessment system of osteoarthritis in the rabbit has been published recently. The aim of the study was to investigate the effectiveness of quantitative T2 mapping evaluation for articular cartilage lesions of a rabbit model of anterior cruciate ligament transection (ACLT) osteoarthritis.</p><p><b>METHODS</b>Twenty New Zealand White (NZW) rabbits were divided into ACLT surgical group and sham operated group equally. The anterior cruciate ligaments of the rabbits in ACLT group were transected, while the joints were closed intactly in sham operated group. Magnetic resonance (MR) examinations were performed on 3.0T MR unit at week 0, week 6, and week 12. T2 values were computed on GE ADW4.3 workstation. All rabbits were killed at week 13, and left knees were stained with Haematoxylin and Eosin. Semiquantitative histological grading was obtained according to the osteoarthritis cartilage histopathology assessment system. Computerized image analysis was performed to quantitate the immunostained collagen type II.</p><p><b>RESULTS</b>The average MR T2 value of whole left knee cartilage in ACLT surgical group ((29.05±12.01) ms) was significantly higher than that in sham operated group ((24.52±7.97) ms) (P=0.024) at week 6. The average T2 value increased to (32.18±12.79) ms in ACLT group at week 12, but remained near the baseline level ((27.66±8.08) ms) in the sham operated group (P=0.03). The cartilage lesion level of left knee in ACLT group was significantly increased at week 6 (P=0.005) and week 12 (P<0.001). T2 values had positive correlation with histological grading scores, but inverse correlation with optical densities (OD) of type II collagen.</p><p><b>CONCLUSION</b>This study demonstrated the reliability and practicability of quantitative T2 mapping for the cartilage injury of rabbit ACLT osteoarthritis model.</p>

Magnetic resonance urography and X-ray urography findings of congenital megaureter / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To observe the imaging findings of congenital megaureter in order to enhance the understanding of this disease.</p><p><b>METHODS</b>Image data of 5 patients with congenital megaureter and 2 misdiagnosed patients were analyzed, and image findings of congenital megaureter were summarized.Elscint Prestig 2.0T superconductive magnetic resonance urography (MRU) with conventional sequence (spin-echo, T1WI560 ms/16 ms; fast spin-echo, T2WI 9600 ms/96 ms ) was performed. Raw data were acquired with fastspin-echo sequence from heavy T2-weighted image (9600 ms/120 ms). Post-processing method of MRU was the maximum intensity projection with three-dimensional reconstruction in the workstation. Intravenous pyelography (IVP) was conducted, in which X-rayfilms were taken 7 minutes, 15 minutes, and 30 minutes after injecting contrast agent, exceptthat in 2 patients the films were taken delayed at 60 and 90 minutes .X-ray retrograde pyelography was performed on 2 patients, successful in one butfailed in the other.</p><p><b>RESULTS</b>The dilated ureter showed hypointensity on T1-weighted images and hyperintensity on T2-weighted images in conventional MRI. The mass wall was intact, uniform in thickness, and showing hypointensity on T1-weighted and T2-weighted images. The MRU images showed a retroperitoneal mass appearing as an elongated tubular cystic structure spreading from kidney to bladder. MRU also revealed dilated calices and renal pelvis, pelviureteric obstruction, and renal duplication. The main signs of congenital megaureter in X-urography was significant dilatation of ureter, or normal renal pelvis with ureter dilatation, hydronephrosis, deformity, and displacement.</p><p><b>CONCLUSIONS</b>MRU with X-urography could visualizethe characteristics of congenital megaureter, including the dilation of renal pelvis and ureter, calculi, urinary tract duplication, and stenosis location. The two techniques can complement each other in disease diagnosis and provide more detailed information for preoperative treatment.</p>

Quantitive evaluation of coronary artery stenosis and in-stent restenosis by 64-slice spiral CT angiography and DSA / 中华放射学杂志

Objective To evaluate the diagnostic accuracy and reliability for coronary artery stenosis and in-stent restenosis detection using 64-slice spiral computed tomography(multislice CT,MSCT) angiography and digital subtraction angiography(DSA).Methods A pulsating cardiac phantom with two simulated coronary arteries was scanned on a 64- slice CT scanner and underwent DSA at static state,at 4 different sinus rhythms of 0,50,70,and 90 beats per minute(bpm).One simulated artery was 3 mm in lumen diameter with 3 segments of 25%,50%,and 75% stenoses.A stent with 2 segments of 50% and 75% stenoses was placed into the other artery with 4mm in lumen diameter.Images from MSCT were analyzed and compared with those from DSA.Results(1)The mean values of the 25%,50%,and 75% stenoses measured with MSCT were(30.0?1.4)%,(49.5?1.3)%,and(72.9?3.9)%,respectively (P values were 0.005,0.531,and 0.369 respectively).The mean values of the 25%,50%,and 75% stenoses measured with DSA were(24.8?2.0)%,(48.2?2.1)%,(75.3?2.4)% respectively (P values were 0.883,0.180,and 0.796,respectively).(2)MSCT was susceptible to heart rate,with artifact increasing as heart rate increasing,especially when the heart rate were ≥70 bpm.(3)There was a good correlation between 64-slice MSCT and DSA(r=0.995,P=0.000).(4)64-slice MSCT could show the stent and in- stent restenosis simutaneously.Its capability to depict in-stent restenosis was limited.The depiction rate of 50% in- stent restenosis were(46.4?4.5)%(0 bpm)and(43.6?5.7)%(50 bpm) respectively(P