选择腰椎椎弓根螺钉长度的放射解剖学研究

目的 :探讨在腰椎侧位片及CT片上推算椎弓根螺钉长度的方法 ,为临床提供参考。方法 :随机在 3 0个腰椎骨标本上用 1mm软钢丝在椎弓根最狭窄处缠绕 ,按人字嵴进钉方法打入椎弓根直钢丝 ,拍正侧位片、横断面片及椎弓根CT扫描 ,分别在标本、CT及侧位片上测量椎弓根螺钉长度 ,三组数据比较。结果 :腰椎侧位片上测量的自关节突关节间隙下缘至椎体前缘距离乘以 0 .83即是螺钉长度 ,椎弓根CT扫描测量其长度更为准确。结论 :正常拍照条件下 ,用腰椎侧位片和椎弓根CT片可准确地推算螺钉长度 ,具有临床实用意义。     

Infrared spectroscopy: A new diagnostic tool in Alzheimer disease

Biological markers play an evolving role in the diagnosis of Alzheimer disease (AD). We compare conventional measurements of cerebrospinal fluid (CSF) tau and β-amyloid_1–42 proteins to a novel approach – Fourier transformed infrared (FT-IR) spectroscopy – a simple technique derived from chemical and physical sciences that characterizes intramolecular bonds. For automatic diagnostic analysis, we developed an artificial neural network (ANN). We examined 71 patients with a clinical diagnosis of AD and 66 controls. β-Amyloid_1–42 was decreased (sensitivity 80% and specificity 78%); tau was elevated (sensitivity 76% and specificity 88%) in CSF of AD patients. The combined tau/β-amyloid_1–42 quotient was able to distinguish healthy from diseased subjects with 99% sensitivity and 86% specificity. The ANN could separate FT-IR spectroscopy data with 88.5% sensitivity and 80% specificity. FT-IR spectroscopy proved to be cost-effective and simple to perform. Diagnostic sensitivity and specificity is in the range of CSF tau and β-amyloid_1–42 protein analysis. Larger sample numbers for ANN training and validation could increase diagnostic accuracy and thus prove to be a useful screening tool.     

Near‐infrared spectroscopy determined brain and muscle oxygenation during exercise with normal and resistive breathing

To elevate effects of carbon dioxide (CO₂) retention by way of an increased respiratory load during submaximal exercise (150 W), the concentration changes of oxy‐ (ΔHbO₂) and deoxy‐haemoglobin (ΔHb) of active muscles and the brain were determined by near‐infrared spectroscopy (NIRS) in eight healthy males. During exercise, pulmonary ventilation increased to 33 (28–40) L min^–1 (median with range) with no effect of a moderate breathing resistance (reduction of the pneumotach diameter from 30 to 14 and 10 mm). The end‐tidal CO₂ pressure (P_ETCO ₂) increased from 45 (42–48) to 48 (46–58) mmHg with a reduction of only 1% in the arterial haemoglobin O₂ saturation (S_aO ₂). During control exercise (normal breathing resistance), muscle and brain ΔHbO₂ were not different from the resting levels, and only the leg muscle ΔHb increased (4 (–2–10) μM , P < 0.05). Moderate resistive breathing increased ΔHbO₂ of the intercostal and vastus lateralis muscles to 6 ± (–5–14) and 1 (–7–9) μM (P < 0.05), respectively, while muscle ΔHb was not affected. Cerebral ΔHbO₂ and ΔHb became elevated to 6 (1–15) and 1 (–1–6) μM by resistive breathing (P < 0.05). Resistive breathing caused an increased concentration of oxygenated haemoglobin in active muscles and in the brain. The results indicate that CO₂ influences blood flow to active skeletal muscle although its effect appears to be smaller than for the brain.     

螺旋CT动态扫描对肝癌大血管侵犯的对比研究

目的 :进一步认识肝癌大血管侵犯的螺旋CT表现特征。方法 :75例肝癌伴大血管侵犯的病例中 ,2 6例前瞻性设计了动脉期同层面扫描加全肝门静脉期扫描的程序 ,选择兼顾病变及门静脉的靶平面 ,并与 31例双期扫描和 18例单纯门静脉期扫描的病例作对照。结果 :动脉期同层面扫描在动 静脉瘘和门静脉早显方面优于双期扫描 ,动脉期对显示大血管侵犯征象有特征性 ,癌栓在动脉期总强化率为 66 67% ( 38/ 5 7例 ) ,单纯门静脉期扫描不能显示动 静脉瘘和癌栓新生血管。结论 :动脉期同层面扫描能显示肿瘤和大血管侵犯引起的血流动力学异常 ,有助于定性和发现动 静脉瘘     

空回肠结肠多发性憩室的临床X线诊断

目的 探索空回肠结肠多发性憩室的临床X线表现,评价消化道造影的诊断价值。方法 对18例患者的临床及X线表现进行了回顾性分析。结果 空肠多发性憩室12例,其中并发十二指肠多发性憩室10例,2例合并回肠多发性憩室。结肠多发性憩室6例,1例并发回肠多发性憩室及结肠癌。结论 空肠多发性憩室多并发于十二指肠多发性憩室,近－中段是好发部位。结肠多发性憩室多见于右半结肠,可有结肠变形。未见独立发生的回肠多发性憩室。钡餐造影能够确诊,小肠灌钡及钡灌肛可提高发现率。     

化学感受器瘤的X线、CT、MRI表现分析

目的：探讨X线,CT、MRI对化学感受器瘤的诊断价值。方法,收集5例经手术病理证实的化学感受器瘤,分析其X线,CT、MRI表现,结果：颈动脉体瘤血管造影显示肿瘤敌国供丰富,颈动脉分叉张开,呈握球状改变;MRI表现为肿瘤T1、T2-WI均呈高信号,并显示瘤内血管流空现象。肺部化学感受器瘤X线表现为类圆形、密度均匀、边缘清楚致密阴影腹后腔化学感受器瘤血管造影、CT均表现为血供丰富的肿块,瘤内可有缺血坏死的低密度区。结论：血管造影,CT、MRI颈部化学感受器瘤具有特征性的表现,而对其他部位病变的定位、定量诊断准确度高,但定性诊断尚有限度。     

中耳占位性病变的CT诊断

目的：探讨中耳不同占位性病变的CT诊断及鉴别诊断问题。方法：对手术病理证实的25例中耳良性及恶性占位性病变患者的CT图像资料进行分析,分别总结其CT诊断及鉴别诊断要点。结果：（1）胆脂瘤：肿物多为单发,中心多位于上鼓室或鼓窦入口区,常破坏鼓室盾板,骨破坏区边缘多清晰硬化,常见听小骨受压移位表现。（2）炎性肉芽肿：肿物呈多发结节状或斑片状,病灶常相连并紧贴鼓室或鼓窦壁附壁分布伴边缘清楚的骨破坏。（3）中耳癌：肿物及骨破坏区形态极不规则,边缘模糊不清,可累及中耳结构以外的骨结构;骨破坏区达乳突或岩骨边缘者,CT横断层面示乳突或岩骨边缘骨壁呈“多点中断”表现。结论：听小骨移位及鼓室盾板骨破坏为诊断胆脂瘤最可靠和重要的依据;骨破坏区边缘模糊,乳突或岩骨边缘骨壁呈“多点中断”表现为中耳癌的特征性CT征象。     

呼气相电子计算机体层扫描在诊断慢性气道疾病方面的应用

目的：评价呼气相电子计算机体层扫描（CT）在诊断慢性气道疾病方面的应用价值。方法：对25例临床确诊为慢性气道疾病的患者（病例组）12例健康志愿者（对照组）,使用螺旋CT分别进行吸气末和呼气末的胸部CT扫描,测量和计算横断面积衰减分数（CLARS）、肺密度衰减值（LDAV）、象素指数（PI）。对两组结果进行了比较。结果：病例组和对照组的横断面积衰减分数分别为25和48,肺密度衰减值分别为79HU和186HU,呼气末病例组和正常对照组的PI值分别为11．36％和0．13％,两组结果有显著统计学差异。结论：呼气相CT对慢性气道疾病的诊断和定量有较大的帮助,能够在一定程度上反映气道的功能,是一种有发展前途的检查方法。     

计算机X线摄影的临床应用

计算机X线摄影（CR）是一个较新的概念,能有效地减少X线摄影的失败,并提供一个更完整的解剖境界,以帮助放射医师显示图像。该技术能改善靶点的清晰度和定性,使投照放射学有其他数字技术的功能,包括电子贮存、电子检索、传递数字网络及数字影像处理,在多房产运用此设备时,CR技术是一个经济的方法,它代表了计算机X线摄影的潜在优势。我们认为使用CR对于资金有限的情况下改善影像质量是实用的和有价值的。在今后的10年内,许多医学影像中心以CR取代屏－片X线摄影是可能的。