Long-term computed tomography follow-up after open surgical repair of abdominal aortic aneurysms

Purpose: To describe the findings on computed tomography (CT) of the aortic sac (AS) in patients operated on for abdominal aortic aneurysm (AAA) with insertion of a coated Dacron prosthesis.

Material and Methods: A prospective study of 36 consecutive patients operated on for AAA over 2 years and followed longitudinally with CT for up to 10 years.

Results: All patients had a fluid-filled AS on CT 7-10 days postoperatively. At 6 months, the AS had decreased in most patients, mainly in the antero-posterior diameter, and in two had disappeared completely. In five patients with complications, the AS increased in size. The AS disappeared completely at 10 years' follow-up in 13 patients. When present, a retroperitoneal hematoma always disappeared after 6 months.

Conclusion: These data indicate that the AS after graft implantation will diminish gradually but will persist for at least 6 months. Usually the transverse diameter is bigger than the antero-posterior diameter. If the AS enlarges and becomes rounded and distended with an inhomogeneous interior, it might be a sign of graft infection. In these cases an ultrasound-guided or CT-guided puncture is recommended.     

肺动脉瘤的MSCTA

目的：探讨多层螺旋CT血管成像（MSCTA）诊断肺动脉瘤（PAA）的价值。方法：回顾性分析7例经临床确诊的PAA临床及影像资料。所有病例均行64层螺旋CT扫描,所获数据传输至工作站进行三维后处理。结果：7例PAA均累及肺动脉干,其中2例为单纯肺动脉干动脉瘤,4例同时累及左、右肺动脉,1例累及左肺动脉。MSCTA表现为肺动脉干及分支的瘤样扩张。结论：MSCTA可简单明确诊断PAA,并将逐步取代肺动脉造影成为诊断PAA的可靠有效检查方法。     

CT血管造影对脑动脉瘤的临床应用价值

目的 评价ＣＴ血管造影（ＣＡＴ）对脑动脉瘤的诊断价值。方法 脑动脉瘤,１９例行ＤＳＡ检查,１８例手术。用最大强度投影（ＭＩＰ）法进行血管重建。结果 ２０例患者中ＤＳＡ及手术发现２１个动脉瘤,ＣＴＡ发现０个。１９例为单发,１９例为单发,１例为多发（２个）,ＤＳＡ示位于基底动脉和左后交通动脉,ＣＴＡ未能显示后者动脉径为３～３３ｍｍ。１例有血管。靶重建、ＣＴＡ像与原始图像后交通动脉,ＣＴＡ像与原有显始图     

Endovascular coil embolization of residual or recurrent aneurysms after surgical clipping

Purpose: Treatment of residual or recurrent aneurysms after surgical clipping is a challenge and most surgeons prefer to avoid a second surgical attempt. We present treatment of 4 residual or recurrent aneurysms after surgical clipping with electrolytically detachable coils.Material and Methods: In 3 of 4 patients, recurrent aneurysms were diagnosed with angiography 2 months, 5 years and 14 years after surgery, although the domes of the aneurysms were opened following clipping during the surgery. In the 4th patient, an early postoperative angiogram revealed filling of a residual aneurysm secondary to the incomplete neck clipping. Guglielmi detachable coils were used to occlude the residual or recurrent aneurysm.Results: The endovascular approach was successful in all patients and the control angiograms showed complete obliteration of the aneurysms with no recanalization.Conclusion: The endovascular approach is a good treatment option for patients in whom complete obliteration of the aneurysm cannot be achieved by surgical clipping. Opening of the aneurysm sac after clipping does not necessarily preclude aneurysm regrowth from a neck remnant proximal to the clip.     

Dynamic computed tomography of cerebral parenchymal tuberculomata

Summary The technique of intravenous dynamic cranial computed tomography has been applied to our patient population in Saudi Arabia in which parenchymal tuberculomata make up approximately 10–15% of all cerebral mass lesions. A spectrum of perfusion patterns was observed in tuberculosis progressing from presentation, through treatment, to resolution. These patterns reflect the microscopic vascular evolution of tuberculomata and parallel at least in part the effects of treatment. The method of dynamic scanning further demonstrates its value in improving the specificity of computed tomography in the evaluation of cerebral masses, thereby enhancing patient-beneficial triage.Presented at the 7th Meeting of the Pan African Association of Neurological Sciences: 27–30 April, 1986, Abidjan, Ivory Coast     

High-dose contrast-enhanced computed tomography (CECT) with iopamidol in the detection of cerebral metastases

Summary Intravenously admistered iodinated contrast media have been demostrated, since early experience with computed tomography of the brain, to improve clinical value of the procedure for detecting intracranial lesions. There is no universal agreement about the amount and the method of administration of the contrast medium. Many authors maintain that the use of large doses gives better results for the diagnosis of tumors and metastases. The purpose of this paper is to evaluate the tolerance of iopamidol administered by rapid intravenous infusion in a large number of patients undergoing contrast enhanced computed tomography to detect brain metastases. The authors examined 969 consecutive adult patients suffering from lung cancer, brain metastases have been detected in 17% of cases. Adverse reactions to contrast media occurred in 3 patients. Non ionic contrast media are recommended in this diagnostic procedure.     

脑动脉瘤螺旋CT血管造影的评价

目的：探讨螺旋CT血管造影在脑动脉瘤诊断和治疗中的价值。方法：16例脑动脉瘤患者行SCTA和DSA检查，并进行对照研究，其中8例行MRI检查。4例行GDC栓塞治疗，2例巨大动脉瘤行球囊导管栓塞术，1例行外科手术，其余病例行内科保守治疗。结果：所有16例动脉瘤均在SCTA和DSA上清晰显示，瘤颈和瘤体大小2种方法测量统计学差异无显著性意义(P值均＞0.05)，对瘤壁钙化、瘤内情况如血栓、瘤颈情况、动脉瘤在颅内空间定位及动脉瘤与载瘤动脉的关系，SCTA较DSA具有优势，又对瘤体及瘤颈的测量SCTA较DSA方便、准确，SCTA操作简单、微创、无危险性，患者易于接受。结论：SCTA对动脉瘤具有诊断作用，可作为脑动脉瘤诊断的筛查技术，对其治疗有重要的指导作用，可作为动脉瘤术前常规检查。     

Accuracy of high resolution computed tomography in direct diagnosis of cerebral aneurysms

Summary With high resolution computed tomography (CT) of the skull, performing rapid series of 1.5 mm slices during an intravenous bolus injection of contrast medium, an angiography-like image (angio-CT) of the basal cerebral arteries can be obtained. From 76 consecutive angiographically or autopsy-verified cerebral aneurysms of vaious size down to 3 mm in diameter, 74 (97.4%) were shown up by the angio-CT. One ruptured and one incidental aneurysm escaped CT visualization. Besides the correct localization of the aneurysms, angio-CT provides information concerning the size and main direction of the aneurysms and yields, in addition, a coronal view of the aneurysms and their surrounding structures. Pitfalls for mis-diagnosis can be the following: Aneurysms of below 5 mm in diameter, located at the supraclinoid part of the carotid artery, multiple or non-ruptured aneurysms, bony or movement artefacts, poorly contrasted vessels due to wrong injection technique of contrast medium or vasospasm, and incorrect interpretation.     

C臂CT在颅内动脉瘤诊疗中研究进展

C臂CT在血管内介入治疗中的应用越来越广泛,其较高的空间分辨率和术中影像即时采集,为临床提供了更多选择。颅内动脉瘤诊断金标准仍为DSA,C臂CT可提供更多信息辅助动脉瘤诊断。术中即刻获取影像可为支架置放提供参考,较为清晰地显示支架、动脉瘤、弹簧圈等相对位置,这在术后随访中也有相当大的价值。现就C臂CT在颅内动脉瘤诊断、治疗和随访复查中的应用研究进展作一综述。     

螺旋CT血管造影在脑动脉瘤血管内栓塞治疗中的价值

目的 探讨螺旋CT血管造影（SCTA）在指导脑动脉瘤血管内栓塞治疗中的应用价值。方法 脑动脉瘤患者48例,行SCTA明确动脉瘤的部位、形态及与载瘤动脉、邻近其他结构的关系,选择最佳显示动脉瘤与载瘤动脉关系的角度,测量动脉瘤的瘤颈、瘤体大小及动脉瘤与载瘤动脉的夹角,以指导血管内电解可脱弹簧圈（GDC）栓塞治疗。1周内行DSA造影,合适病例行GDC栓塞治疗,将SCTA与DSA结果进行对照比较。结果 （1）SCTA检出了DSA确诊的56个脑动脉瘤中的53个（94．6％）,正确诊断51个（91．1％）。（2）43个脑动脉瘤选择血管内GDC栓塞治疗,SCTA选择的血管内治疗的最佳投照角度与DSA相符41个（95．35）,SCTA测量这41个动脉瘤的瘤体与载瘤动脉夹角、瘤体及瘤颈大小并分别与DSA测量值比较,差异均无显著性意义（P值均＞0．05）。SCTA选择最佳投照角度及测量数值应以最大密度投影（MIP）图像为准,结合表面遮盖法（SSD）图像。结论 SCTA不仅对脑动脉瘤的诊断准确率高,而且对动脉瘤治疗方案的制定、术前准确及血管内栓塞治疗有很高的指导价值。     

Multi-slice computed tomography angiography in the diagnosis of pulmonary artery aneurysms

目的:探讨多层螺旋CT血管成像(MSCTA)诊断肺动脉瘤(PAA)的价值.方法:回顾性分析7例经临床确诊的PAA临床及影像资料.所有病例均行64层螺旋CT扫描,所获数据传输至工作站进行三维后处理.结果:7例PAA均累及肺动脉干,其中2例为单纯肺动脉干动脉瘤,4例同时累及左、右肺动脉,1例累及左肺动脉.MSCTA表现为肺动脉干及分支的瘤样扩张.结论:MSCTA可简单明确诊断PAA,并将逐步取代肺动脉造影成为诊断PAA的可靠有效检查方法.     

多层螺旋CT血管造影在主动脉瘤腔内带膜内支架置入术后并发症诊断中的应用

目的：探讨多层螺旋CT血管造影（CTA）在主动脉瘤腔内带膜内支架置入术后并发症诊断中的应用。方法：31例腹主动脉瘤和主动脉夹层腔内带膜内支架置入术后行多层螺旋CT血管造影，采用准直2.5mm，层厚3.0mm，螺矩6-8，重建方法为容积显示（VR）、表面遮盖显示（SSD）、最大密度投影法（MIP）及多层面重建法（MPR）。观察图像确定有无术后并发症，并比较4种重建方法对并发症的显示情况。结果：31例中有1例术后内支架出现局限性断裂，VR、MIP及MPR均清晰显示了内支架的变化，SSD未能显示。1例内支架展开不良，4种重建方法均明确显示；5例术后出现渗漏，VR及MPR清晰显示渗漏的部位、形态及内漏量，MIP、SSD仅显示其中的4例。在显示支架内血流情况及瘤周血栓方面，VR及MPR能明确支架内有无血栓形成及腔内带膜内支架置入术后的转归变化，VR及MPR显示1例术后支架内血栓形成，SSD及MIP未能显示。结论：多层螺旋CTA有利于主动脉瘤腔内带膜内支架置考试术后并发症的诊断；VR及MPR图像优于SSD及MIP，能为术后内支架情况作出更准确的判断 。     

Gadolinium-enhanced computed tomography angiography in multi-detector row computed tomography: initial observations

Rationale and Objectives. The feasibility of using gadolinium contrast medium for computed tomography angiography (CTA) in multi-detector row computed tomography and the effect of contrast medium dilution was investigated.Materials and Methods. Three pigs were each scanned in multiple sessions with injections of non-dilute and dilute contrast medium at a dose of 0.3 mmol/kg body weight. Non-spiral dynamic scanning at a fixed mid-abdominal aortic level and thoracoabdominal CTA were performed.Results. The magnitude of peak aortic enhancement was not significantly different between dilute and non-dilute contrast medium injections (P = .88), but the former showed earlier enhancement (mean of 2.3 seconds sooner, P < .01) than the latter. CT angiography with gadolinium contrast medium showed much lower enhancement than iodine contrast medium, but small vessels were readily identifiable.Conclusion. Gadolinium contrast medium combined with multi-detector row computed tomography may provide clinically useful CTA. Dilution of contrast medium shortens the enhancement time but has little effect on the magnitude.     

The value of computed tomography in cerebral syphilis

Summary The computed tomographic findings of three patients with cerebral syphilis, including cerebral gumma, which regressed completely under penicillin therapy, syphilitic angiitis with cerebral infarction, and syphilitic cerebral atrophy, are reported. CT is unable to provide specific diagnostic data for these conditions. The etiology can be clarified only by taking into consideration the clinical findings and course, the serological results, and the result of therapy.     

数字减影CT血管成像对颅内小动脉瘤的诊断价值

目的：评价数字减影 CT 血管成像(DSCTA)在颅内小动脉瘤诊断中的价值。方法回顾性分析92例经数字减影血管造影(DSA)或手术确诊为颅内动脉瘤患者的临床及 CT 影像资料,比较 DSCTA 和常规 CT 血管成像(CTA)2种技术对颅内动脉瘤检测的准确性。结果92例患者经证实共有102个动脉瘤,DSCTA 检出其中100个,常规 CTA 检出其中89个(χ2=8.707,P =0.003)。DSCTA 漏诊海绵窦段和床突下段动脉瘤各1例,而常规 CTA 漏诊13例床突下段及海绵窦段与颅骨紧贴<5.0 mm 的小动脉瘤。进一步将<3.0 mm 和3.0~5.0 mm 的动脉瘤合并计算,DSCTA 对检出5.0 mm 以下动脉瘤的敏感性显著高于常规CTA 技术(χ2=8.393,P =0.004)。结论DSCTA 对颅内动脉瘤诊断优于常规 CTA,尤其对颅底毗邻小动脉瘤的诊断有明显的优势,可作为筛查和诊断颅内动脉瘤的首选检查技术。     

Noninvasive gadolinium-enhanced three dimensional computed tomography coronary angiography

RATIONALE AND OBJECTIVES: Although the use of gadolinium (Gd)-based contrast agents for angiographic studies of abdominal aorta, renal vasculature, and digital subtraction angiography has been reported, no studies have shown their diagnostic efficacy and image quality in coronary computed tomography angiography (CTA). The aim of this study is to evaluate the image quality of Gd-based contrast agents during coronary CTA. MATERIALS AND METHODS: A phantom study was done to evaluate the attenuation of serial dilutions of Gd and iodinated agents. This study was done on a 64-slice multirow detector CT (MDCT) scanner and e-speed scanner and CT attenuation Hounsfield units (CTHU) were compared. We evaluated 35 consecutive patients who underwent Gd-enhanced CTA. CTHU of aorta was measured at first, mid, and lowest slice levels with and without contrast administration. The image quality was graded on the basis of visualization of the coronary arteries (scale I-III; III demonstrating diagnostic image quality of the distal-most vessels). In a substudy, four patients with borderline renal insufficiency underwent CTA using Gd and iodinated contrast agents admixed in a 50:50 ratio. RESULTS: The phantom study showed that enhancement of various dilutions of Gd and iodine resulted in near identical CTHU with both e-speed and 64-slice scanners (r(2) > or = 0.997). Mean CTHU with contrast at the top slice was 116 HU, at middle slice was 125 HU, and at the lower slice was 93 (111.14 +/- 22). Quality evaluation showed 2 grade III, 9 grade II, and 24 grade I images (average quality of images 1.35). Mean CTHU was 222. CONCLUSION: Gd-enhanced contrast medium provides adequate enhancement of coronary vasculature, allowing for diagnostic evaluation of coronary arteries with new CT systems. Use of newer generations of multirow detector CT scanners should further enhance the quality of images.     

Computed tomography angiography in detection and characterization of ruptured anterior cerebral artery aneurysms at uncommon location for emergent surgical clipping

INTRODUCTION: Cerebral subarachnoid hemorrhage may result from rupture of saccular aneurysms at uncommon location [excluding the anterior communicating artery (ACOM)] of the anterior cerebral artery (ACA). The purpose of this study was to evaluate the usefulness of helical computed tomography angiography (CTA) in detection and characterization of intracranial aneurysms at such uncommon locations before emergent surgical clipping. MATERIALS AND METHODS: Between 1998 and 2003, records for 50 consecutive patients who underwent emergent surgical clipping for intracranial aneurysms were reviewed. Eighteen of these patients had aneurysms in the ACA. After those patients with unequivocal ACOM aneurysms were excluded, eight patients with eight aneurysms in an uncommon location of the ACA were recruited to this study. Plain computed tomography (CT) and CTA were performed in eight patients, and digital subtraction angiographies were done in three patients. Each aneurysm was evaluated for the detection, quantification, and characterization of the aneurysms with 2D multiplanar reformatted and 3D volume-rendering techniques. RESULTS: There were two small aneurysms arising from the A1 segment, one from the A2 segment, two at the junction of triplicated ACAs, two at the junction of A2 and A3 segments, and one at the junction of A2 and A3 segments of the azygos ACA. The average diameter of the aneurysmal sac was 4.44 mm (range, 2.7-7.0 mm), and the aneurysmal neck averaged 2.59 mm (range, 1.2-3.5 mm) in size. The smallest aneurysm measured 2.2x1.8x2.7 mm (neck, 1.2 mm) in the A1 segment of the left ACA. Three patients had intracerebral hematoma, seven had intraventricular hemorrhage, and three had acute hydrocephalus. CONCLUSION: Aneurysms in uncommon locations of ACAs exhibited characteristic features. Rupture of these aneurysms can cause intracerebral hematoma, intraventricular hemorrhage, and/or acute hydrocephalus. Noninvasive CTA can reliably detect and characterize intracranial aneurysms at such uncommon location for planning of emergent surgical intervention.     

螺旋CT血管造影三维成像在脑动脉瘤诊断中的应用

目的:探讨螺旋CT血管造影(SCTA)三维成像及其在脑动脉瘤诊断中的作用。方法:分析23例经手术或血管造影证实的脑动脉瘤,将其术前行螺旋CT血管造影容积扫描所得数据传输到工作站,用表面遮盖法(SSD)、最大密度投影(MIP)等技术进行3D重建。结果:23例患者,共检出脑动脉瘤25个,其中2例为2个。所示病例经SSD、MIP重建处理后能够全面直观地显示动脉瘤的大小、形态、位置,能多方位观察瘤体与载瘤动脉的空间解剖关系。结论:运用多种三维成像技术,能充分显示动脉瘤的空间解剖结构,可部分代替传统脑血管造影,并可作为该病的临床筛选手段。     

Diagnostic accuracy of cardiac computed tomography angiography for myocardial infarction

AIM:To investigate diagnostic accuracy of high,low and mixed voltage dual energy computed tomography(DECT) for detection of prior myocardial infarction(MI).METHODS:Twenty-four consecutive patients(88% male,mean age 65 ± 11 years old) with clinically documented prior MI(> 6 mo) were prospectively recruited to undergo late phase DECT for characterization of their MI.Computed tomography(CT) examinations were performed using a dual source CT system(64-slice Definition or 128-slice Definition FLASH,Siemens Healthcare) with initial first pass and 10 min late phase image acquisitions.Using the 17-segment model,regional systolic function was analyzed using first pass CT as normal or abnormal(hypokinetic,akinetic,dyskinetic).Regions with abnormal systolic function were identified as infarct segments.Late phase DE scans were reconstructed into:140 kVp,100 kVp,mixed(120 kVp) images and iodine-only datasets.Using the same 17-segment model,each dataset was evaluated for possible(grade 2) or definite(grade 3) late phase myocardial enhancement abnormalities.Logistic regression for correlated data was used to compare reconstructions in terms of the accuracy for detecting infarct segments using late myocardial hyperenhancement scores.RESULTS:All patients reported prior history of documented myocardial infarction,with most occurring more than 5 years prior(n = 18;75% of cohort).Fiftyfive of 408(13%) segments demonstrated abnormal wall motion and were classified as infarct.The remaining 353 segments were classified as non-infarcted segments.A total of 1692 segments were analyzed for late phase enhancement abnormalities,with 91(5.5%) segments not interpretable due to artifact.Combined grades 2 and 3 compared to grade 3 only enhancement abnormalities demonstrated significantly higher sensitivity and similar specificity for detection of infarct segments for all reconstructions evaluated.Evaluation of different voltage acquisitions demonstrated the highest diagnostic performance for the 100 kVp reconstruction which had higher diagnostic accuracy(87%;95%CI:80%-90%),sensitivity(86%-93%;95%CI:54%-78%) and specificity(90%;95%CI:86%-93%) compared to the other reconstructions.For sensitivity,there were significant differences noted between 100 kVp vs 140 kVp(P<0.0005),100 kVp vs mixed(P<0.0001),and 100 kVp vs iodine only(P<0.005) using combined grade 2 and grade 3 perfusion abnormalities.For specificity,there were significant differences noted between 100 kVp vs 140 kVp(P<0.005),and 100 kVp vs mixed(P<0.01) using combined grades 2 and 3 perfusion abnormalities.CONCLUSION:Low voltage acquisition CT,100 kVp in this study,demonstrates superior diagnostic performance when compared to higher and mixed voltage acquisitions for detection of prior MI.     

肺静脉变异的MSCT研究

目的:探讨MSCT对肺静脉与左心房连接方式各种变异的显示,为临床提供解剖学信息。方法:收集例行冠状动脉CTA检查且排除影响肺静脉疾病者共712例,其中男449例,女263例;年龄34～82岁,平均59.63岁。以原始横断面CT图像为基础,采用VR、MIP及MPR等后处理方法,观察并统计肺静脉开口数目、副肺静脉及肺静脉共同开口情况,进行分型,并对肺静脉共干、副肺静脉在性别及肺静脉变异左右侧别有无差异进行统计学分析。结果:肺静脉可分为4种类型,标准型最常见,共532例(74.7%);副肺静脉型85例(11.9%),其中左副肺静脉6例,右副肺静脉72例,最上肺静脉7例;肺静脉共同开口型86例(12.1%),其中左侧肺静脉共干76例,右侧肺静脉共干6例,双侧肺静脉共干4例;混合型9例(1.3%)。肺静脉的变异率为25.3%。副肺静脉发生率男性为14.3%,女性11.4%,肺静脉共干发生率男性14.0%,女性12.2%,以上性别差异无统计学意义。肺静脉变异率左侧13.3%(95/712),右侧12.8%(91/712),差异无统计学意义。结论:肺静脉的解剖变异较大,对肺静脉进行合理的分型,有助于肺静脉与左心房关系的解剖学评估,可为临床手术及房颤射频消融治疗提供有价值的肺静脉解剖路线图。