肺动静脉瘘的影像学诊断

目的:探讨肺动静脉瘘不同影像学方法的诊断价值。材料与方法:9例肺动静脉瘘分别作了心血管造影、核磁共振及CT检查及心脏超声。结果:9例中6例为局限性的肺动静脉瘘,3例为弥漫性的肺动静脉瘘,3例中2例有肝脏疾病史。结论:肺动静脉瘘心血管造影为主要的诊断手段,但对毛细血管床前型的弥漫性肺动静脉瘘诊断有局限性,MRI、CT对局限性的肺动静脉瘘的诊断有帮助,心脏超声有助于毛细血管床前型的弥漫性肺动静脉瘘诊断。     

Radionuclide left ventricular volume determination. Influence of scattered radiation and surrounding activity

Summary. Radionuclide measurements of left ventricular volumes, ejection fractions and stroke volumes were performed by an equilibrium technique in nine patients using left anterior oblique projection and individual depth correction. Phantom studies were made in order to evaluate attenuation and scattering of the radiation. It was found that a simple depth correction factor, k(d)= e^μd, can be used under certain conditions. However, the determination of left ventricular volume by radionuclide techniques is not a truly absolute method. The depth correction factor to be used is dependent on the condition of measuring and evaluation, for instance how the region of interest for the left ventricle is selected. Therefore, this method should be carefully standardized, evaluated and compared to other techniques. Stroke volume measured by radionuclide and dye-dilution technique showed a correlation coefficient of 0·76 (nine patients) at rest and 0·77 (seven patients) at work. This method can be easily performed during routine ejection fraction determination and can thus be useful in clinical studies.     

心脾综合征中肺静脉回流的影像学诊断

目的:分析76例心脾综合征中肺静脉回流特点对手术的影响,并评价其影像学诊断方法。方法:76例均做了心血管造影。其中38例做了MRI检查。结果:56例无脾综合征中33例伴肺静脉异位引流(APVC),28例为完全性肺静脉异位引流(TAPVC),12例为心上型,3例为心下型。20例多脾综合征中,5例伴APVC。结论:心脾综合征肺静脉回流特点多样,完全性肺静脉异位引流发生率高,术前正确诊断对先天性心脏病的手术治疗很重要。心血管造影仍有很高的诊断价值,造影增强磁共振血管成像(CE-MRA)是最好的辅助诊断方法。     

16层CT冠状动脉成像技术及临床应用

目的探讨16层CT冠状动脉成像(CTCA)的技术要点及临床应用价值。方法对76例患者(临床疑诊为冠心病者65例,支架置入术后8例,冠脉旁路成形术后3例)进行回顾性心电门控平扫及增强,后处理用VesselView软件包对所有病人做了多平面重建(MPR)、最大密度投影法重建(MIP)、容积再现技术(VRT)重建及血管剖面技术分析;其中35例可疑冠心病患者有选择性冠状动脉造影(SCA)作比较。以管腔直径减少≥50%作为判定狭窄的标准,对各冠状动脉主要分支进行节段(血管直径≥2mm)分析。结果85.1%的冠状动脉节段图像质量可以用于评价,可较准确地显示冠状动脉通畅情况及管壁病变。与SCA对照,敏感度和特异度分别为86.5%(32/37)和95.1%(214/225),若将不能满足诊断要求的46节段算在内,则敏感度为78.0%(32/41)。结论16层CT冠状动脉成像可显示较长节段的冠状动脉,较为准确地认定冠状动脉病变,具有较高的临床应用价值。     

Operator-interactive method for simultaneous measurement of left and right ventricular volumes and ejection fraction by tomographic electrocardiography-gated blood pool radionuclide ventriculography

BACKGROUND: A method that uses single photon emission computed tomography (SPECT) equilibrium radionuclide angiocardiography (ERNA) to measure right ventricular (RV) and left ventricular (LV) volumes (in milliliters) and ejection fraction (EF) is described. METHODS AND RESULTS: We recorded 35 paired SPECT ERNA and electron beam computed tomography (EBCT) cardiac studies in 27 patients; for comparison with EBCT, a method for measurement of RV and LV volumes and EF with SPECT ERNA was developed in 18 paired studies and was validated and assessed for reproducibility in 17. Validation indicated that SPECT ERNA and EBCT were similar for measurement of RV volume (end-systolic and end-diastolic volumes in a combined analysis) and EF (180+/-74 mL vs 182+/-80 mL and 0.44+/-0.11 vs 0.43+/-0.11, respectively) and for measurement of LV volume and EF (88+/-36 mL vs 84+/-43 mL and 0.53+/-0.081 vs 0.59+/-0.07, respectively). The SPECT ERNA method was quite reproducible. CONCLUSIONS: RV and LV volumes and EF can be measured readily via SPECT ERNA.     

完全性肺静脉畸形连接X线与超声心动图的对照研究

本文对１９例手术证实的完全性肺静脉畸形连接进行了Ｘ线（平片、造影）及超声心动图的对照研究，结果表明平片对引流入左上腔静脉者有相当的价值，心内型者无特异性。Ｍ型超声心动图诊断本症限度大，双维超声既能定性亦能做出分型诊断。对混合型完全性肺静脉畸型连接以及其他诸型亚型的诊断，仍以造影检查最佳。     

Cardiac evaluation of candidates for kidney transplantation: value of exercise radionuclide angiocardiography

In view of the high incidence and mortality of coronary artery disease (CAD) in patients with kidney transplantation, a systematic cardiac evaluation was prospectively performed in 103 uraemic patients eligible for transplantation. After clinical examination, 28 patients with symptoms of CAD or diabetes mellitus were referred directly for coronary angiography, whereas the remaining 75 patients had rest and exercise radionuclide angiocardiography for evaluation of possible asymptomatic CAD. Among them, left ventricular ejection fraction was below 40% at rest or fell during exercise by at least 5 EF% in 12 patients; coronary angiography in nine showed CAD in four and hypertensive heart disease in five. In the remaining 63 (of 75) patients without severe resting left ventricular dysfunction or exercise ischaemia, the follow-up of 28 +/- 7 months revealed no clinical manifestation of CAD. Overall incidence of CAD in symptomatic and asymptomatic patients during a follow-up of 27 months after cardiac evaluation was 20 and 25% in nondiabetic and diabetic candidates for kidney transplantation, respectively (P = n.s.). Thus, clinical examination combined with exercise radionuclide angiocardiography in patients without signs or symptoms of heart disease had a high predictive accuracy for presence or absence of late manifestations of CAD. Exercise radionuclide angiocardiography is therefore a useful method for screening kidney transplantation candidates for asymptomatic CAD.     

On-line evaluation of systolic performance by densitometry in digital left ventriculography

The angiocardiographic evaluation of left ventricular end-diastolic (LVEDV) and end-systolic (LVESV) volumes and ejection fraction (EF) is routinely performed by the area-length method (ALM) but may lead to erroneous results. Digital imaging in real time allows densitometric procedures of determining left ventricular (LV) performance to be applied alternatively. In this study, we present densitometric algorithms for the analysis of LVEDV, LVESV, and EF from digital image data, establish accuracy and reproducibility, and determine value and limitations in comparison with ALM in single-plane 30°right anterior oblique (RAO) projection. A linear relationship between iodine depth and measured densities is mainly burdened with scatter radiation and beam hardening which reduce primary radiation and suppress iodine depth. However, facilities such as deconvolution and correction algorithms are capable of reducing these sources of error. In the present study, computer-analyzed contrast images of iodine-filled wedges and spheres showed a near-linear relationship between iodine depth between 50-100 mg/cm² and measured densities. Contrast images of heart casts and LV an-gio-grams of 54 patients were obtained with a digital image acquisition and processing system, and evaluated by two in dependent observers. The phantom study resulted in significantly (p≤0.01) better densitometric standard errors of estimate for volumes [3.3 ml densitometry (DENS) vs. 8.9 ml (ALM)] and simulated EF [4.3% (DENS) vs. 7.8% (ALM)] than ALM. The standard error of estimate for the comparison between both methods was 8.4 ml for volumes and 7.5% for EF. Densitometric volumes tended to underestimate volumes calculated by ALM. The angiographic study of patients demonstrated significant correlations between both methods (LVEDV r = 0.78, LVESV r = 0.83, total volumes: r = 0.89;EF r = 0.88). The standard errors of estimate can be ascribed to systematic, method-related errors of both DENS and ALM (LVEDV ± 28.9 ml, LVESV ± 23.4 ml, total volumes (EDV and ES V) ± 27.1 ml; EF ± 8.1 %). The intra- and interobserv-er variability, respectively, exhibited significantly smaller (p ≤0.01 and p ≤0.05, respectively) standard errors of estimate for densitometric EF [4.6% (DENS) vs. 8.5% (ALM) and 7.1% (DENS) vs. 10.3% (ALM), respectively]. Inclined but not significant differences were found for LVEDV and LVESV. In conclusion, the data presented indicate that the calculation of LV volumes and EF in digital left ventriculography may be performed accurately by densitometric calculation in single-plane 30°RAO projection. Minor underestima-tions in densitometric volume determination may be anticipated in the evaluation of LV geometry.     

Pediatric cardiac angiography using a 4 French Catheter

Thirty specially designed 4 French pigtail white Teflon catheters 50 cm in length were utilized for angiography using the retrograde arterial approach in 26 infants and children. Angiographic opacification was considered very satisfactory. Apart from one episode of temporary occlusion of the right coronary artery ostium, there were no other significant complications. The catheters were introduced percutaneously in 21 instances and distal pulses were palpable in 18 patients by the second day after catheterization. At postcatheterization testing with increasing volumes and flow rates, the first rupture occurred, delivering 13 ml at 13 ml/second. On testing an additional 15 catheters using fixed volumes of 5, 10, and 15 ml at increasing flow rates, rupture first occurred at 34, 22, and 18 ml/second, respectively. We conclude that this small catheter is relatively safe and satisfactory for the retrograde arterial approach in the study of infants and children.