Assessment of Coronary Stents by 64-slice Computed Tomography: In-stent Lumen Visibility and Patency

Objective To assess lumen visibility of coronary stents by 64-slice computed tomography (CT) coronary angiography, and determine the value of 64-slice CT in non-invasive detecting of in-stent restenosis after coronary artery stent implantation. Methods Totally, 60 patients (54 males, aged 57.0±12.7 years) and 105 stents were investigated by 64-slice CT at a mean interval of 20.0±16.6 months after coronary stents implantation. Axial multi-planar reconstruction images of the stents and curved-planar reconstruction images through the median of the stents were reconstructed for evaluating stent image quality on a 5-point scale (1=excellent, 5=non assessable), and stent lumen diameter was detected. Conventional coronary angiography was performed in 18 patients, and 32 stents were evaluated. Results Image quality was good to excellent on average (score 1.71±0.76). Stent image quality score was correlated to heart rate (r=0.281, P<0.01) and stent diameter (r=-0.480, P<0.001). All the stents were assessable in lumen visibility with an average visible lumen diameter percentage of 60.7%±13.6%. Visible lumen diameter percentage was correlated to heart rate (r=-0.193, P<0.05), stent diameter (r=0.403, P<0.001), and stent image quality score (r=-0.500, P<0.001). Visible lumen diameter percentage also varied depending on the stent type. In comparison with the conventional coronary angiography, 4 of 6 in-stent stenoses were correctly detected. The sensitivity and specificity for the detection of in-stent stenosis were 66.7% and 84.6%, respectively. Conclusions Using a 64-slice CT, the stent lumen is partly visible in most of the stents. And 64-slice CT may be useful in the assessment of stent patency.

Long-term effect of triamcinolone acetonide in the treatment of upper lid retraction with thyroid associated ophthalmopathy

AIM： To report the long-term outcomes of a large cohort of upper lid retraction patients treated with subconjunctival triamcinolone acetonide injections.METHODS： This retrospective clinical study was conducted from 2009 to 2016. The documents of 97 patients（126 eyes） were reviewed. The patients were treated with subconjunctival triamcinolone acetonide injections monthly and evaluated pre-and post-treatment by taking measurements of the upper margin reflex distance（MRD1, the distance between the upper-lid margin and the pupil center）, lid aperture, lagophthalmos and proptosis. The patients were divided into the cured group, the improved group and the ineffective group based on the final treatment effectiveness. The improved group and the ineffective group were combined into non-cured group.RESULTS： The follow-up time was 23.45±14.86 mo. Of the patients, 63（64.9%） were assigned to the cured group, 22（22.7%） in the improved group, 12（12.4%） in the ineffective group. Injection times for cured group was 4.66±1.74, and for non-cured group was 5.17±2.08（P≤0.05）. The MRD1 was significantly reduced between baseline and 1 mo after the initiation of treatment in the cured and improved groups（P〈0.001）. The values did not change significantly after 4 mo for the improved group, while they continued to decrease in the cured group. In the ineffective group, the MRD1 did not significantly change after treatment. A statistically significant difference was observed between the baseline and post-treatment values of the mean muscle thickness（2.95±0.99 mm vs 2.04±0.63 mm, P〈0.05） and surface area（27.27±10.5 mm2 vs 18.3±7.04 mm2,P〈0.05） of the levator superioris with magnetic resonance imaging examination. Twelve patients（12.4%） relapsed after treatment and required additional subconjunctival injections. The main side effects included menstrual cycle disturbances（32%） and elevations of intra-ocular pressure（18.6%）. CONCLUSION： A repeated subconjunctival injection of triamcinolone is an effective and relatively safe treatment for upper lid retraction due to thyroid-associated ophthalmopathy. This is related to the anti-inflammation effect of the medicine and the levator thickness can become thinner. Patients must be monitored regularly for recurrences and side effects.

CORONARY ANGIOGRAPHY WITH DUAL SOURCE COMPUTED TOMOGRAPHY:INITIAL EXPERIENCE

Objective To explore the scan technique and image quality of coronary angiography with dual source computed tomography(CT) without oral metoprolol preparation.Methods Plain and enhanced dual source CT coronary angiography without oral metoprolol preparation was prospectively performed in 600 patients.Calcium scoring with plain scan images as well as multi-planar reconstruction(MPR),maximum intensity projection(MIP),and volume rendering technique(VRT) reconstruction with enhanced scan images were performed in all cases.The scan technique and post-reconstruction experience was summarized.The image quality was classified as 1 to 4 points,and coronary segments classified according to the American Heart Association standards were evaluated.Results The average calcium score of the 600 cases was 213.6±298.7(0-3 216.5).The average heart rate of the enhanced scan was 82.1±16.2(47-139) bpm.The post-reconstruction methods with which coronary segments could be shown as best as possible consisted of single phase reconstruction method,two or more phases supplemented method,and electrocardiogram editing method.Altogether 8 457 coronary segments were evaluated,among which 97.2% were evaluated as point 1,1.7% point 2,0.5% point 3,and 0.6% point 4.The coronary segments in 261 cases were completely normal,while 360 segments were diagnosed with <50% stenosis and 625 segments with ≥50% stenosis.Conclusions Excellent coronary artery image can be obtained with dual source CT in patients with any heart rate without oral metoprolol preparation.Heart rate is not a major source of the artifact,coronary segments can be well shown with single or multiple-phase reconstruction method.

Normative Measurements of Extraocular Musculature by Multislice Computed Tomography

Objective To establish the normal measurements of diameter of extraocular muscles (EOMs) by multislice computed tomography (CT). Methods Orbits of 50 volunteers (25 male and 25 female) were scanned with a multislice CT scanner. For each subject, one axial image at the central level of the eyeball, one coronal image about 1 cm behind globe, and two oblique sagittal images respectively along the left and right optic nerve were used for measurements of the thickness and width of EOMs. The statistic significance of measurement value between male and female and between left and right eyes was evaluated. Results There were no significant differences in the thickness and width of superior muscle group, lateral rectus, medial rectus, lateral rectus, superior oblique, inferior oblique and the thickness of levator palpebrae superioris between the left and right eyes as well as between male and female groups (all P>0.05). The thickness of superior muscle group and inferior rectus had not significant difference (2.9±0.7 vs. 3.3±0.8 mm, P=0.162), while the thickness of medial rectus was significantly higher than that of lateral rectus (3.1±0.5 vs. 2.2±0.6 mm, P=0.000). Conclusions The CT measurement of extraocular musculature is simple and time-saving and can be applied in the clinical work. The normative data obtained may be useful in determining pathologic enlargement of the EOMs in both thyroid-associated orbitopathy patients and other various orbital conditions.

Electromechanical coupling effect on electronic properties of double-walled boron nitride nanotubes

We report on a first-principles study of a novel band modulation in zigzag double-walled boron nitride nan- otubes （DBNNTs） by applying radial strain and coupled ex- ternal electric field. We show that the band alignment be- tween the inner and outer walls of the DBNNTs can be tuned from type I to type II with increasing radial strain, accompa- nied with a direct to indirect band gap transition and a sub- stantial gap reduction. The band gap can be further signifi- cantly reduced by applying a transverse electric field. The coupling of electric field with the radial strain makes the field-induced gap reduction being anisotropic and more re- markable than that in undeformed DBNNTs. In particular, the gap variation induced by electric field perpendicular to the radial strain is the most remarkable among all the modu-lations. These tunable properties by electromechanical cou- pling in DBNNTs will greatly enrich their versatile applica- tions in future nanoelectronics.

RETROSPECTIVE ANALYSIS OF MAGNETIC RESONANCE MYOCARDIAL DELAYED ENHANCEMENT

Objective To explore the imaging and related clinical characteristics of magnetic resonance (MR) delayed enhancement in patients with ischemic or nonischemic heart disease. Methods Thirty-two cases who underwent MR myocardial cine and delayed enhancement imaging from January 2004 to October 2006 were retrospectively analyzed. The cine sequence imaging included the four-chamber view and the left ventricular short axis view. The delayed enhancement imaging was taken 10 minutes after the infusion of gadolinium from the antecubital vein with a segmented inversion-recovery-prepared T1-weighted fast gradient echo sequence. Patients underwent coronary computed tomography angiography (CTA) two weeks before or after the MR imaging examination. Combined with clinical history, the clinical and MR imaging characteristics of the patients who had delayed enhancement were analyzed. Results MR delayed enhancement could be found in 16 cases. Among them, 12 cases had ischemic heart disease. Their coronary CTA showed one to three vessel diseases. The delayed enhancement was transmural or subendocardium, and the area of delayed enhancement corresponded well with one or more coronary arteries which had severe stenosis or occlusion. Four cases had nonischemic heart diseases. One case was dilated cardiomyopathy, with diffuse small midwall spots in delayed enhancemen and only 30% stenosis of the anterior descending coronary artery in coronary CTA. One case was hypertrophic cardiomyopathy, with delayed enhancement of strip- and patch-shaped at midwall of the hypertrophic myocardium. One case was restrictive cardiomyopathy, and the delayed enhancement was located in the area of subendocardium of both the right and left ventricles. Coronary CTA of these two cases were normal. The other case was a mass of the lateral wall of the left ventricle, and the delayed enhancement with a clumpy shape was located in the lateral wall of the left ventricle. Conclusions MR myocardial delayed enhancement is not a specific sign of myocardial infarction of ischemic heart disease. Nonischemic heart diseases including all kinds of primary cardiomyopathy and some other diseases affecting myocardium can also cause delayed enhancement, but their characteristics are different. The differentiation of the etiology of the nonischemic heart disease with delayed enhancement relies upon the intimate connection with clinical history and the cine sequence MR images.

ASSESSMENT OF MYOCARDIAL VIABILITY WITH CONTRAST-ENHANCED MAGNETIC RESONANCE IMAGING AND COMPARISON WITH SINGLE-PHOTON EMISSION COMPUTED TOMOGRAPHY

客观：与 chronicischemic 心疾病在病人为对心肌的生存能力的评价把提高对比的磁性的回声成像(ceMRI ) 与原子新陈代谢的成像作比较。方法：二十个病人与怀疑长期化学家心疾病经历了单个光子的排放计算了的 ceMRI 和 technetium-99m sestamibi 断层摄影术(SPECT ) 。有积极 SPECT 结果的病人也经历了 18F-fluorodeoxyglucose (FDG ) SPECT。在 a17 片断模型，由 ceMRI 的亢奋的改进(SEH ) 的部分程度由 SPECT 与部分 FDG 和 sestamibi 举起相比。在亢奋的改进 byceMRI 和左室的功能的程度之间的关联被分析。结果：七个病人在 ceMRI 和 technetium-99m sestamibi SPECT 两个都得到了否定结果。剩余的有积极结果的 13 个病人然后经历了 18F-FDG SPECT。在 13 个病人的 221 个片断， SEH 是( 2.1 +/- 8.2 )%，( 25.0 +/- 13.7 )%，并且( 57.7 +/- 23.6 )在有正常新陈代谢/灌注，新陈代谢/灌注失配，和匹配的缺点的片断的%，分别地并且他们中的任何一个二个之间有重要差别(所有 P 【 0.05 )。由操作典型曲线分析的接收装置，在为在可行、不能生存的片断之间的区别的曲线 was0.95 下面的区域。在 34% 的截止价值， SEHoptimally 区分了从 SPECT 定义的不能生存的片断可行。用这阀值， ceMRI 的敏感和特性由 SPECT were92% 定义检测是的不能生存的心肌层并且 93% 分别地。由 ceMRI 的 Hyperenhancement 尺寸与左室的喷射部分否定地被相关(r =- 0.90， P 【 0.01 ) 并且断然与左室的体积(r= 0.62 为结束心脏舒张的体积， r = 0.75 为结束收缩的体积，两 P 【 0.05 ) 。结论: CeMRI 与 chronicischemic 在病人与高精确性允许对心肌的生存能力的评价心疾病。

Resolution of Pseudoptosis after Anti-inflammatory Treatment of the Contralateral Eye in Thyroid-associated Ophthalmopathy

Thyroid-associated ophthalmopathy （TAO） is an autoimmune inflammatory disease. Pseudoptosis （or ptosis）, which involves a reduction in the opening of the upper eyelid with a normal levator muscle, is rarely reported in TAO patients. In this article, we reported three cases of unilateral pseudoptosis due to inflammation of the levator in the contralateral eye. The effect of the unilateral use of triamcinolone acetonide （TA） on contralateral lid position and contour was also investigated.