CT的分叶征表现在肺内孤立结节影像诊断中的价值

目的探讨CT的分叶征表现在肺内孤立结节影像诊断的价值以及CT多平面重组（MPR）对此征检出的意义。方法观察病理证实的周围型小肺癌137例及良性肺内结节45例，将结节的边缘分为4型。对28例肺癌、22例良性结节行MPR，考察其显示分叶征的作用。引入可能性比值（likelihood ratios，LR）以量化良恶性病变在形态学上存在重叠的表现。结果Ⅰ型边缘结节对良性病变的特异性为83．3％（20／24），敏感性为44．4％（20／45）。Ⅳ型边缘结节对周围型小肺癌的特异性为97．6％（83／85），敏感性为60．7％（83／137）。表明Ⅰ型边缘是良性病变的特点；而Ⅳ型边缘是恶性病变的特征。Ⅳ型边缘的结节恶性病变在MPR重组图像上的检出率为64．3％（18／28），与横断面扫描差异有统计学意义（P〈0．01）。结论分叶征对肺内孤立结节的诊断有价值，MPR配合横断面薄层图像有助于提高该征的检出率。     

多层螺旋CT血管成像在支气管动脉灌注化疗前的定位价值

目的探讨多层螺旋CT血管成像(MSCTA)在支气管动脉(BA)灌注化疗前的定位价值。方法分析15例经支气管动脉介入治疗前的的肺癌病例,中央型13例,周围型2例。15例均行螺旋CT增强扫描,后传至工作站利用多平面重组(MPR)、最大密度投影(MIP)和容积再现(VR)等后处理技术观察支气管动脉。结果13例中央型肺癌均由肿瘤性支气管动脉供血,重建图像清晰显示肿瘤性支气管动脉的起点、分支情况及走行特点;其中2例右侧肿瘤性支气管动脉与肋间动脉共干。2例周围型肺癌中有1例由肿瘤性支气管动脉供血,1例找不到明确发自支气管动脉的供血血管。结论多层螺旋CT血管成像能够显示肺癌特别是中央型肺癌的肿瘤性支气管动脉并能为经支气管动脉灌注化疗提供准确定位。     

肺灌注显像在Ⅲ期非小细胞肺癌调强放疗中对功能肺的保护

目的 探讨肺灌注显像在Ⅲ期非小细胞肺癌(NSCLC)调强放疗(IMRT)保护功能肺的可行性。方法 选择拟行放疗的Ⅲ期NSCLC患者24例,分别行PET-CT和SPECT定位,图像传至治疗计划系统进行图像融合。根据SPECT图像确定功能肺(FL)和非功能肺(NFL),FL是指放射性计数为最大放射性计数的30%以上(包括30%)的区域,其他区域为NFL。肺灌注受损分为4级:0级,无灌注受损;1级,肿瘤及其周围局部肺灌注受损;2级,达1叶肺灌注受损;3级,超过1叶肺灌注受损。根据SPECT图像提供的肺功能信息制定IMRT计划进行优化,尽可能降低FL的照射体积剂量。采用配对t检验统计分析优化前后的IMRT计划的肺组织剂量参数变化。结果 患者均有不同程度的肺灌注缺损,其中肺灌注受损1级8例,2级6例,3级10例。根据SPECT提供的肺功能信息优化IMRT计划后WLV和FLV均有不同程度降低,而FLV降低程度更加明显。优化后WLV₁₀、WLV₁₅、WLV₂₀、WLV₂₅、WLV₃₀和FLV₁₀、FLV₁₅、FLV₂₀、FLV₂₅、FLV₃₀差异有统计学意义。结论 根据SPECT图像提供的肺功能信息优化IMRT计划以保护Ⅲ期NSCLC功能肺是可行的。     

CT对急性坏死性胰腺炎的诊断和预后评价

目的探求CT对急性坏死性胰腺炎的诊断及预后的关系。方法回顾性分析符合急性坏死性胰腺炎15例患者并做CT扫描,其中10例增强扫描。结果胰腺呈局限性肿胀者9例,普遍性肿胀者6例,胰腺实质内见到点状低密度灶5例,片状低密度影10例,其中4例同时有小片状高密度出血影;10例增强扫描中,低密度坏死灶与正常胰腺有明显的对比。胰腺周围有大量渗出和3例形成假囊性肿物,1例形成＂气泡＂样脓肿。结论CT征象不仅能对急性坏死胰腺炎做出正确诊断,同时对预后的评价都有重要的指导意义。     

家族性颅骨锁骨发育不全的影像学表现(附6例分析)

目的探讨家族性锁骨颅骨发育不全的X线及CT表现特征。方法分析6例(2个家庭)锁骨颅骨发育不全的临床、X线及CT表现,并从遗传学角度进行探讨。结果家族性锁骨颅骨发育不全的X线及CT表现主要为颅顶膨隆或下陷、囟门未闭、颅缝增宽、多发缝间骨、颅底相对较窄,蝶骨短、蝶窦小,颅底骨明显增厚,并呈棉花团状改变,边缘模糊、牙齿发育不良、锁骨发育不全或缺如、全身骨骼发育不全。结论家族性锁骨颅骨发育不全的X线及CT表现具有特征性,能够作出正确的诊断。     

CT导引经皮穿刺注射无水乙醇治疗溶骨性骨转移瘤

目的探讨CT导引下经皮穿刺注射无水乙醇（CT～PEI）治疗溶骨性骨转移瘤的价值及安全性。方法对17例骨转移瘤患者（25个病灶）采用CT—PEI治疗，使用无水乙醇和超化碘油10：1的混合剂，用CT精确定位、准确穿刺瘤灶并密切监控无水乙醇弥散情况及用量，以减少并发症。对接近椎管及椎间孔的病灶，采用利多卡因实验性治疗以避免严重并发症。术前及术后定期CT检查，3例病人行同位素骨扫描检查，与治疗前检查进行对照研究。对患者随访3～30个月观察其临床疗效。结果所有患者经1次CT—PEI治疗后，疼痛即明显减轻，经2～3次CT-PEI治疗后疼痛完全缓解（CR）16例（24处病灶），疼痛部分缓解（PR）1例。术后随访3个月时，23处病灶内肿瘤组织均发生坏死，被高密度碘油混合液均匀浸润。其中，9处病灶体积缩小。随访3～30个月，除1例因周边出现新的肿瘤浸润灶而再次出现疼痛，其余病例转移瘤处止痛效果无反复。所有病例无严重并发症。结论CT—PEI是一种治疗骨转移瘤有效、微创、安全、简便的方法，使骨转移瘤内肿瘤组织坏死，最大限度的杀灭肿瘤细胞，从而达到满意的止痛效果，明显改善恶性肿瘤溶骨性转移病人的生活质量。     

Evaluation of left ventricular mechanical dyssynchrony as determined by phase analysis of ECG-gated SPECT myocardial perfusion imaging in patients with left ventricular dysfunction and conduction disturbances

Background  Cardiac resynchronization therapy (CRT) is approved for the treatment of patients with advanced systolic heart failure and evidence of dyssynchrony on electrocardiograms. However, a significant percentage of patients do not demonstrate improvement with CRT. Echocardiographic techniques have been used for more accurate determination of dyssynchrony. Single photon emission computed tomography (SPECT) myocardial perfusion imaging has not previously been used to evaluate cardiac dyssynchrony. The objective of this study is to evaluate mechanical dyssynchrony as described by phase analysis of gated SPECT images in patients with left ventricular dysfunction, conduction delays, and ventricular paced rhythms. Methods and Results  A novel count-based method is used to extract regional systolic wall thickening amplitude and phase from gated SPECT images. Five indices describing the phase dispersion of the onset of mechanical contraction are determined: peak phase, phase SD, bandwidth, skewness, and kurtosis. These indices were determined in consecutive patients with left ventricular dysfunction (n=120), left bundle branch block (n=33), right bundle branch block (n=19), and ventricular paced rhythms (n=23) and were compared with normal control subjects (n=157). Phase SD, bandwidth, skewness, and kurtosis were significantly different between patients with left ventricular dysfunction, left bundle branch block, right bundle branch block, and ventricular paced rhythms and normal control subjects (all P<.001) Peak phase was significantly different between patients with right ventricular paced rhythms and normal control subjects (P=.001). Conclusions  A novel SPECT technique for describing left ventricular mechanical dyssyn-chrony has been developed and may prove useful in the evaluation of patients for CRT. This study was funded in part by a research grant from the Medtronic-Duke Strategic Alliance, of which Dr Borges-Neto is the primary investigator.     

Myocardial perfusion SPECT reconstruction: Receiver operating characteristic comparison of CAD detection accuracy of filtered backprojection reconstruction with all of the clinical imaging information available to readers and solely stress slices iteratively reconstructed with combined compensation

BACKGROUND: Past receiver operating characteristic (ROC) studies have demonstrated that single photon emission computed tomography (SPECT) perfusion imaging by use of iterative reconstruction with combined compensation for attenuation, scatter, and detector response leads to higher area under the ROC curve (A(z)) values for detection of coronary artery disease (CAD) in comparison to the use of filtered backprojection (FBP) with no compensations. A new ROC study was conducted to investigate whether this improvement still holds for iterative reconstruction when observers have available all of the imaging information normally presented to clinical interpreters when reading FBP SPECT perfusion slices. METHODS AND RESULTS: A total of 87 patient studies including 50 patients referred for angiography and 37 patients with a lower than 5% likelihood for CAD were included in the ROC study. The images from the two methods were read by 4 cardiology fellows and 3 attending nuclear cardiologists. Presented for the FBP readings were the short-axis, horizontal long-axis, and vertical long-axis slices for both the stress and rest images; cine images of both the stress and rest projection data; cine images of selected cardiac-gated slices; the CEQUAL-generated stress and rest polar maps; and an indication of patient gender. This was compared with reading solely the iterative reconstructed stress slices with combined compensation for attenuation, scatter, and resolution. With A(z) as the criterion, a 2-way analysis of variance showed a significant improvement in detection accuracy for CAD for the 7 observers (P = .018) for iterative reconstruction with combined compensation (A(z) of 0.895 +/- 0.016) over FBP even with the additional imaging information provided to the observers when scoring the FBP slices (A(z) of 0.869 +/- 0.030). When the groups of 3 attending physicians or 4 cardiology fellows were compared separately, the iterative technique was not statistically significantly better; however, the A(z) for each of the 7 observers individually was larger for iterative reconstruction than for FBP. Compared with results from our previous studies, the additional imaging information did increase the diagnostic accuracy of FBP for CAD but not enough to undo the statistically significantly higher diagnostic accuracy of iterative reconstruction with combined compensation. CONCLUSIONS: We have determined through an ROC investigation that included two classes of observers (experienced attending physicians and cardiology fellows in training) that iterative reconstruction with combined compensation provides statistically significantly better detection accuracy (larger A(z)) for CAD than FBP reconstructions even when the FBP studies were read with all of the extra clinical nuclear imaging information normally available.     

腔隙性脑梗死的MRI与CT的诊断价值

目的:探讨腔隙性脑梗死的影像学特点及其临床意义,比较MRI和CT的诊断价值。方法:对120例经临床、MRI诊断明确为腔隙性脑梗死患者的病灶形态大小、部位、数量进行统计。结果:①120例行MRI检查患者共发现病灶890个,最多见于豆状核(占40.8%),其次为放射冠、丘脑、内囊、尾状核、桥脑,可为圆形、椭圆形、条索状病灶。②32例既做CT,又做MRI患者中,MRI检出的病灶数为CT的5.1倍,其中绝大多数CT漏检病灶直径≤5mm或位于幕下。结论:①腔隙性脑梗死常为多发,且第一次临床发病时多数患者颅内已存在无症状性腔隙性脑梗死病灶;②腔隙性脑梗死灶易为CT忽略,尤其是幕下病灶或≤5mm的病灶,这是造成既往文献报道腔隙性脑梗死好发部位差异较大的一个主要原因;③尽管腔隙性脑梗死病灶较小(≤10mm),但大部分(60.0%)急性期存在在周边水肿,需要相应的临床治疗。     

Interobserver Agreement for the Diagnosis of Venous Thromboembolism on Computed Tomography Chest Angiography and Indirect Venography of the Lower Extremities in Emergency Department Patients

Objectives: To determine interobserver agreement between radiologists for computed tomography (CT) angiography and venography. CT venography of the lower extremities combined with standard CT angiography of the chest may result in an increased overall diagnosis rate of venous thromboembolism (pulmonary embolism or deep venous thrombosis).
Methods: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other.
Results: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest κ = 0.83) and was good for CT venography (85%, κ = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT.
Conclusions: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography.