螺旋CT图像噪声的评价

目的 :评价螺旋CT中内插方式、螺距以及重建间隔对噪声的影响。方法 :采用SomatomPlus 4螺旋CT机。在相同条件下扫描直径为 2 0cm的水模 ,测得水模图像中心 40cm2 兴趣区的CT值标准差作为评价噪声水平的指标。结果 :3 60°线性内插的噪声减少 (t =3 4.87,P <0 .0 0 1) ,180°线性内插的噪声增加 (t =18.78,P <0 .0 0 1)。螺距大于 1.0或小于 1.0与螺距为 1.0时噪声水平的差异无显著性意义 (P >0 .0 5 )。随着重建间隔改变 ,相应噪声水平的差异无显著性意义 (P >0 .0 5 )。结论 :与常规扫描相比 ,螺旋CT内插方式对噪声有一定影响 ,而螺距与重建间隔对噪声水平影响不明显。     

外伤性脑梗死的CT诊断(附39例分析)

目的：探讨螺旋CT在外伤性脑梗死诊断中的价值及其特征。方法：对39例头颈部外伤后临床主要表现为不同程度的偏瘫患者行横断面螺旋CT扫描，分析外伤性脑梗死的CT表现。结果：根据临床和CT表现分为两型：I型(21例)，外伤性腔隙性脑梗死，好发于基底节-内囊区，均位于豆状核、尾状核及内囊区，呈小片状腔隙性低密度区；Ⅱ型(18例)，外伤性大面积脑梗死，为脑叶梗死呈扇形低密度区，与大脑前中后供血动脉或颈内动脉分布一致，范围较大。结论：螺旋CT扫描检查对外伤性脑梗死的准确诊断、估计病变程度，分析两型脑梗死的不同发生机制，为临床诊断、治疗及判断预后提供重要信息。     

Intraoperative Diagnosis Using Sentinel Node Biopsy with Indocyanine Green Dye in Gastric Cancer Surgery: An Institutional Trial by Experienced Surgeons

Background

Reliable indicators that can intraoperatively determine the absence of nodal metastasis are in great demand to avoid unnecessary lymphadenectomy. However, little has been reported about the intraoperative diagnostic performance of sentinel node (SN) biopsy.

Methods

Sentinel node biopsy by subserosal or submucosal injection of indocyanine green (ICG) was performed in 241 patients with American Joint Committee on Cancer tumor, node, metastasis staging system, 7th edition, clinical T1 (n = 190) and T2 (n = 51) gastric cancer by two experienced surgeons. All nodes that stained green (green node, GN), representing SNs, were excised before gastrectomy and were sliced into 2-mm sections for intraoperative histological examinations with hematoxylin and eosin staining. The sliced GNs were also examined simultaneously by imprint cytology.

Results

The GNs were detectable in 240 patients (3.8 ± 2.4 nodes per patient; range 1–17 nodes; median 3 nodes), and the success rate of detection was 99.6 % (240 of 241). Of 240 patients with a successful detection, 29 were found to have lymph node (LN) metastases; 16 were diagnosed with LN metastases in both GNs and non-GNs, 12 in GNs alone, and 1 in non-GNs alone. The false-negative rate based on the SN concept was 3.4 % (1 of 29). However, two patients with cT1 gastric cancer were diagnosed as intraoperative GN negative but were later confirmed as GN positive by histological examinations of paraffin sections. As an intraoperative diagnosis, the false-negative rate was 10.3 % (3 of 29).

Conclusions

Sentinel node biopsy using ICG could be performed intraoperatively within reasonable limits under certain conditions, such as multiplanes for detection, combination use of imprint cytology, and open surgery by experienced surgeons.     

Safety, efficacy, and indications of beta-adrenergic receptor blockade to reduce heart rate prior to coronary CT angiography

For selected indications, coronary computed tomographic (CT) angiography is an established clinical technology for evaluation in patients suspected of having or known to have coronary artery disease. In coronary CT angiography, image quality is highly dependent on heart rate, with heart rate reduction to less than 60 beats per minute being important for both image quality and radiation dose reduction, especially when single-source CT scanners are used. β-Blockers are the first-line option for short-term reduction of heart rate prior to coronary CT angiography. In recent years, multiple β-blocker administration protocols with oral and/or intravenous application have been proposed. This review article provides an overview of the indications, efficacy, and safety of β-blockade protocols prior to coronary CT angiography with respect to different scanner techniques. Moreover, implications for radiation exposure and left ventricular function analysis are discussed.     

节细胞神经瘤CT诊断

目的 :探讨节细胞神经瘤的CT诊断。方法 :回顾性分析 4例经手术病理证实的节细胞神经瘤的CT表现 ,并结合相关文献复习 ,讨论其影像特征。结果 :肿瘤位于脊柱旁或肾上腺区 ,直径均 >3 .5cm ,呈卵圆形 ,有完整包膜 ,呈较均匀低密度或欠均匀 ,多数病灶内可见点状高密度钙化。增强扫描呈轻度均匀或欠均匀强化。结论 :节细胞有一定的CT影像特点 ,CT能作出正确的定位及较准确的定性诊断     

Induction of mutagenesis and transformation in BALB/c-3T3 clone A31-1 cells by diverse chemical carcinogens.

BALB/c-3T3 cells were employed to examine the genotoxic potential of a variety of known chemical carcinogens. BALB/c-3T3 cells displayed a dose-dependent transformation response to a variety of carcinogens (polycyclic hydrocarbons, methylating agents, ethylating agents, aflatoxin B1 [AFB1], and 4-nitroquinoline-N-oxide [4-NQO]). When the ability of these compounds to induce mutagenesis to resistance to the cardiac glycoside ouabain (OUAR) was examined, we found the short chain alkylating agents to be particularly effective mutagens, causing biologic effects at doses below those necessary to induce a transformation response. In contrast, the polycyclic hydrocarbons which were potent transforming agents were weaker, albeit significant, mutagens for the OUAR locus in this system, while AFB1 was quite weak. Further studies were performed with 5-azacytidine (5-AZA) and the nongenotoxic carcinogen cinnamyl anthranilate (ClN). 5-AZA was a potent transforming agent, but failed to cause mutagenesis. ClN similarly caused in vitro transformation. When a series of eight structurally diverse compounds were examined in both the BALB/c-3T3 and C3H10T1/2 mouse fibroblast transformation systems, the BALB/c-3T3 system was shown to be sensitive to a wide variety of potential carcinogens, whereas the C3H10T1/2 system proved routinely sensitive only to the polycyclic hydrocarbons.     

儿童腹腔脓肿的CT诊断

目的探讨ＣＴ对儿童腹腔脓肿的诊断价值。方法对２３例经手术和穿刺针吸证实的腹腔脓肿的ＣＴ表现进行分析，急性阑尾炎１３例，升结肠穿孔１例，美克尔憩室炎２例，感染源不明确７例。１９例行平扫与增强检查，４例仅平扫检查。结果脓液ＣＴ值与病程及致病菌种类无关，脓液量与病程呈正相关。５２％脓肿内见到气体影，２２％脓肿内见到小钙化斑。病程１周以上者全部见不均匀厚壁强化的脓肿壁。结论脓肿内见到小钙化斑和气体影像具有特征性，脓腔内较大气液平面提示肠瘘存在，脓肿内无气体影不能排除肠瘘。     

Fostering research by radiologists: recommendations of the 1991 Summit meeting.

At the annual Radiology Summit Meeting sponsored by the Intersociety Commission of the American College of Radiology, leaders of U.S. and Canadian radiologic organizations met in part to discuss ways to improve radiology research. Support by radiology departments and radiologic organizations is currently not sufficient to improve the research of the specialty. Five issues of central importance to improving research are (a) the need for a definition of radiology research, (b) a lack of financial resources, (c) a lack of mentors, (d) hesitancy to embark on a research career, and (e) conflicts between clinicians and researchers. The adoption of 31 recommendations regarding these five issues was urged.