Aortic valve calcification on computed tomography predicts the severity of aortic stenosis

AIM: Incidental aortic valve calcification is often detected during computed tomography. The aim was to compare the severity of valvular stenosis and calcification in patients with aortic stenosis. MATERIALS AND METHODS: One hundred and fifty-seven patients aged 68+/-11 years (range: 34-85) with aortic valve stenosis underwent multislice helical computed tomography and Doppler echocardiography performed by independent, blinded observers. The aortic valve calcium score was determined using automated computer software calibrated with a phantom. RESULTS: Doppler echocardiography demonstrated a post-valve velocity of 3.45+/-0.66 m/s and a peak gradient of 49+/-11 mmHg. Computed tomography showed excellent reproducibility and the median aortic valve calcium score was 5858 AU (interquartile range, 1555-14,596). The computed tomography aortic valve calcium score positively correlated with the Doppler post-valve velocity and peak gradient (r=0.54, p<0.0001 for both) of the aortic valve. All patients with severe aortic stenosis had a calcium score of >3700 AU. CONCLUSION: Calcification of the aortic valve is closely associated with the severity of aortic stenosis, and heavy calcification suggests the presence of severe aortic stenosis that requires urgent cardiological assessment. Patients with lesser degrees of aortic valve calcification should be screened for aortic stenosis and monitored for disease progression.     

CT of aortic aneurysms: the distinction between mural and thrombus calcification

Aortic calcification, either mural or thrombus, is a common finding in patients with abdominal aortic aneurysms. Differentiating between the two sites of calcification is necessary in order to avoid confusing simple thrombus calcification with displaced calcified intima in aortic dissection. The CT scans of 145 cases of abdominal aortic aneurysm and seven cases of abdominal aortic aneurysm with dissection were analyzed with respect to the location of the calcification: mural only or mural and thrombus. Mural calcification was seen in all 152 patients with aneurysms whereas thrombus calcification was identified in only 33 (24%) of the 136 patients with thrombus. Displaced intimal calcification caused by aortic dissection can either appear similar to or, at times, be indistinguishable from thrombus calcification. Thrombus calcification was present in four (57%) of the seven patients with abdominal aortic aneurysms and dissection. To avoid the possibility of a false-positive diagnosis of aortic dissection in patients with abdominal aortic aneurysm, other signs of aortic dissection should be sought such as separation of the true and false lumina by an intimal flap.     

主动脉弓左侧分支追踪法诊断胎儿右位主动脉弓与双主动脉弓

目的探讨主动脉弓左侧分支追踪法诊断胎儿右位主动脉弓与双主动脉弓的价值。资料与方法纳入60例主动脉弓畸形胎儿,于三血管-气管(3VT)切面均探及“U”形环结构。传统横断面扫查法在3VT切面上诊断主动脉弓畸形。追踪法在3VT切面基础上寻找从主动脉弓向左侧发出的血管,观察其走行并作出诊断。结果经尸检或产后超声心动图证实共5例双主动脉弓,46例右位主动脉弓合并左锁骨下动脉迷走,9例右位主动脉弓合并左无名动脉。传统扫查方法与追踪法对胎儿主动脉弓畸形的诊断率分别为63.33%、96.67%,差异有统计学意义(X^2=20.83,P<0.01)。结论追踪主动脉弓左侧分支法可以有效地诊断不同类型的右位主动脉弓及双主动脉弓,方法简单,提高了主动脉弓畸形的检出率。     

Intramural hematomas of the aorta

Intramural hematomas (IMH) are regarded as a hemorrhage into the aortic wall. In general a traumatic form can de differentiated from a spontaneous non-traumatic. There is a predisposition of IMH with arterial hypertension and mesoectodermal dysplastic syndromes. The diagnosis is established with the clinical presentation in combination with the findings of different imaging modalities. Acute and subacute discomfort associated with a tendency of collaps are considered as typical presenting complaints. A semicircular or concentric thickening of the aortic wall with the absence of blood flow or a dissection membran are typical findings in transesophageal echocardiography, computed tomography and magnetic resonance tomography. From a differential diagnostic point of view a distinction from atherosclerotic wall changes, intraluminal thrombi and inflammatory aortic diseases is essential. The IMH is considered as an early presentation of aortic dissection, put into and treated according to the Stanford classification. In the course of natural history an IMH can disappear, rupture or progress into a classic aortic dissection.     

Pitfalls in the diagnosis of thoracic aortic dissection at CT angiography.

Two hundred seventy-five computed tomographic (CT) angiograms of the thoracic aorta were obtained over a period of approximately 4 years in patients with suspected or known aortic dissection. In all cases, unenhanced images were initially obtained, followed by contrast material-enhanced images. A variety of pitfalls were encountered that mimicked aortic dissection. These pitfalls were attributable to technical factors (eg, improper timing of contrast material administration relative to image acquisition); streak artifacts generated by high-attenuation material, high-contrast interfaces, or cardiac motion; periaortic structures (eg, aortic arch branches, mediastinal veins, pericardial recess, thymus, atelectasis, pleural thickening or effusion adjacent to the aorta); aortic wall motion and normal aortic sinuses; aortic variations such as congenital ductus diverticulum and acquired aortic aneurysm with thrombus; and penetrating atherosclerotic ulcer. Although several of these pitfalls are easy to recognize and therefore unlikely to present a diagnostic problem, others are potentially confusing. Familiarity with these common pitfalls, coupled with a knowledge of normal intrathoracic anatomy, will facilitate recognition of true aortic dissection and help avoid misdiagnosis at thoracic aortic CT angiography.     

Digital subtraction angiography of the aortic arch

We evaluated the utility of intravenous digital subtraction angiography (IV DSA) for diagnosing lesions of the aortic arch and great vessels in 25 patients. Digital subtraction angiography (DSA) was found useful in evaluating congenital and acquired lesions of the arch and great vessel origins, and it proved adequate for follow-up of patients who had graft replacement. Cases examined included: right aortic arch, double arch, aortic coarctation, aberrant vascular origins, aortic aneurysm and pseudoaneurysm, changes in atherosclerotic great vessels, and revascularization procedures for patients with pulmonary atresia and aortic interruption. In our experience, DSA is a useful tool for screening and following patients with aortic arch or great vessel lesions; it is often the only diagnostic imaging examination necessary.     

主动脉夹层支架置入术前CT的诊断价值(附9例报告)

目的:探讨主动脉夹层行支架置入术前CT检查的诊断价值及对手术的指导意义.方法:回顾性分析9例主动脉夹层患者的支架置入术及CT影像资料,分析术前CT对支架置入术的指导作用及手术对CT的诊断要求.结果:主动脉夹层支架置入术前行CT平扫、增强及三维重建可较准确地反映主动脉夹层的分型、内膜裂口、周围脏器血供等情况.根据术前CT诊断信息设计手术,8例手术成功,1例术中发现病情发展而中止手术.结论:CT可较准确地诊断主动脉夹层,并为支架置入术提供重要信息.     

Right aortic arch with isolation of the left innominate artery

Isolation of the left innominate artery and right aortic arch, a rare variant of right aortic arch anomalies, was diagnosed in a four-year-old boy with other congenital cardiac anomalies. Isolation of vessels from the aortic arch is predicted from the primitive double aortic arch model of Edwards. In this patient there was no evidence of a vascular ring or of a significant subclavian steal syndrome.     

多层螺旋CT血管造影在主动脉病变诊断中的应用价值

目的:探讨多层螺旋CT血管造影(MSCTA)诊断主动脉病变的能力。方法:对临床可疑主动脉病变75例患者行MSCTA检查,对比剂使用碘海醇90~100ml,流速3~4ml/s,采用Surestar技术跟踪扫描,阈值140~160HU;采用多种图像后处理技术,包括容积重组(VR)、多平面重组(MPR)、曲面重组(CPR)及最大密度投影(MIP)。结果:主动脉瘤20例(发生在开主动脉3例,主动脉弓部7例,腹主动脉10例);主动脉壁内血肿2例,主动脉硬化性溃疡6例,主动脉缩率1例,其中,主动脉瘤及夹层动脉瘤行介入治疗13例,与选择性血管造影结果一致。结论:从SCTA作为一种无创性血管成像技术应用于主动脉病变的诊断,具有安全、可靠、简便、快捷的优势,为临床诊断与治疗提供可靠依据。     

Traumatic laceration of the ascending aorta: angiographic assessment

Radiographic evaluation of ascending aortic injuries is rare because they are almost always immediately fatal. We report three cases of ascending aortic laceration studied by angiography, with a review of the literature and discussion of mechanisms of injury. The type of deceleration trauma resulting in ascending aortic laceration differs from the usual driver deceleration injury in that no attenuation of force on the victim occurs at the time of impact. Traction-torsion forces on the aorta at points of fixation and increased intraluminal aortic pressure are the likely mechanisms of rupture. Adequate angiographic evaluation of these patients requires visualizing the entire aortic arch from aortic valve to diaphragm.     

The aortic diverticulum: A remnant of the partially involuted dorsal aortic root

The aortic diverticulum, a large bulge on the lesser curvature of the aortic isthums, is an occasional variation found during thoracic aortography in patients with a left aortic arch and normal origin of the brachiocephalic arteries. Although it is commonly thought to be a remnant of the closed ductus arteriosus, the results of this study support the hypothesis that it is a remnant of the right dorsal aortic root.     

分体式支架-移植物治疗主动脉病变的初步报告

目的 介绍分体式支架-移植物（separating stent—graft）及其早期应用体会。方法 器械采用12F输送器，先后1次性经皮穿刺置入主动脉分体式支架-移植物的外、内两部分。4例患者为主动脉夹层StanfordB型、胸主动脉瘤与腹主动脉瘤。结果 1例夹层破口被封闭，病灶被隔绝；1例胸主动脉瘤病灶被隔绝，有轻度内瘘；2例腹主动脉瘤，瘤体均被隔绝。结论 分体式支架-移植物治疗主动脉夹层与主动脉瘤是1种有效、方便、更安全、更微创的治疗方法。     

The role of aortic wall CT attenuation measurements for the diagnosis of acute aortic syndromes

Objectives

To determine if measurements of aortic wall attenuation can improve the CT diagnosis of acute aortic syndromes.

Methods

CT reports from a ten year period were searched for acute aortic syndromes (AAS). Studies with both an unenhanced and a contrast enhanced (CTA) series that had resulted in the diagnosis of intramural hematoma (IMH) were reviewed. Diagnoses were confirmed by medical records. The attenuation of aortic wall abnormalities was measured. The observed attenuation threshold was validated using studies from 39 new subjects with a variety of aortic conditions.

Results

The term “aortic dissection” was identified in 1206, and IMH in 124 patients’ reports. IMH was confirmed in 31 patients, 21 of whom had both unenhanced and contrast enhanced images. All 21 had pathologic CTA findings, and no CTA with IMH was normal. Attenuation of the aortic wall was greater than 45 HUs on the CTA images in all patients with IMH. When this threshold was applied to the new group, sensitivity for diagnosing AAS was 100% (19/19), and specificity 94% (16/17). Addition of unenhanced images did not improve accuracy.

Conclusions

Measurements of aortic wall attenuation in CTA have a high negative predictive value for the diagnosis of acute aortic syndromes.     

Blunt traumatic injury of the ascending aorta: multidetector CT findings in two cases

Blunt ascending aortic injuries are rare in clinical practice. We have encountered two types of injuries to the ascending aorta with multidetector computed tomography: (1) a tear of the wall of the aortic root with a contained rupture and associated hemopericardium and (2) a tear at the level of the aortic valve cusp without associated hemopericardium. In reviewing our experience with aortic trauma at our institution under IRB waiver of consent, we encountered two cases of ascending aortic rupture that illustrate the two injury patterns. We present these two cases to alert radiologists to the multidetector computed tomographic findings of this life-threatening injury.     

Three aortic arch anomalies: A review of the literature and proposal of a new classification

Four patients with three rare aortic arch anomalies, all of which can be classified as variants of Edwards' hypothetical double aortic arch system, were studied. The diagnosis was based on angiographic findings in all cases and in addition, on operative findings in three and operative and autopsy findings in one case. All normal and anomalous variants of aortic arches may be incorporated into a new classification based upon Edwards' hypothetical double aortic arch system. In the new classification the term double aortic arch with types A, B, C, or D atresia or interruption of the left or the right arch covers all known arch anomalies. The types A, B, C, and D refer to the site of atresia or interruption of the hypothetical double aortic arch model in relationship to the ductus arteriosus and brachiocephalic vessels.     

MR imaging of congenital anomalies of the aortic arch

Eighteen patients with congenital aortic arch anomalies were evaluated by ECG-gated MR imaging. Transverse images encompassing the heart and thoracic aorta were available in all patients; sagittal or coronal studies were available in 12 patients. Visualization of the aortic arch, its orientation, and the origin and course of the arch vessels was assessed. Associated intracardiac abnormalities were noted, and the effect of aberrant vessels on the trachea or esophagus was determined. Thirteen patients had a right aortic arch. Mirror-image branching was found in 10 cases, and an aberrant left subclavian artery was found in three of these. Three patients had a left aortic arch with aberrant right subclavian artery, and two patients had a double arch. Tracheal compression caused by vascular rings was found in two patients with respiratory symptoms. Corroborating studies (angiography, surgery, CT, and autopsy) in 16 patients confirmed the MR diagnoses in all but one. We conclude that MR could substitute for other techniques as an effective, noninvasive method for the evaluation of congenital aortic arch anomalies.     

An autopsy case of unexpected sudden death due to rupture of a thoracic aortic aneurysm into the left lung

Ruptured aortic aneurysms present with various signs and symptoms depending on the site of rupture and bleeding, often causing sudden death; however, rupture into the lung with hemoptysis and blood aspiration is very rare. We report a case of unexpected sudden death due to blood aspiration from rupture of a thoracic aortic aneurysm into the lung. An 83 year old man, who had a past history of surgery for an abdominal aortic aneurysm about 17 years previously, was found dead on his bed with massive hemoptysis. Medico-legal autopsy revealed rupture of a thoracic aortic aneurysm into the left lung, causing massive blood aspiration. Tight, diffuse pleural adhesion and the vulnerable wall of an aortic aneurysm due to advanced atherosclerosis with active inflammation appeared to have predominantly contributed to the penetration of the ruptured aneurysm into the lung. This case suggests that long-term clinical follow-up and management are needed for a patient with aortic aneurysm, and that a ruptured aortic aneurysm should be taken into consideration to identify the source of bleeding for hemoptysis.     

Radiographic manifestations of congenital anomalies of the aortic arch

This article discusses congenital anomalies of the aortic arch. Many malformations of a left, right, or double aortic arch produce tracheal, bronchial, and esophageal compression and can be recognized on chest radiographs or esophagrams and confirmed by angiography, computed tomography, or magnetic resonance imaging. Other congenital lesions of the aortic arch are characterized by aortic obstruction and include supravalvular aortic stenosis, aortic arch interruption or atresia, and coarctation.     

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 。     

先天性主动脉瓣、瓣上及瓣下狭窄的影像学诊断

目的 :提高影像学诊断先天性主动脉瓣、瓣上及瓣下狭窄的水平。材料和方法 :主动脉瓣狭窄 12例 ,主动脉瓣下狭窄 5例 ,主动脉瓣上狭窄 7例 ,均行X线检查 ,MRI 2 1例 ,心血管造影 (CAG) 15例 ,手术证实 15例。结果 :主动脉瓣狭窄MRI显示瓣膜增厚、瓣口狭窄 2例 ;主动脉瓣下隔膜型狭窄MRI示 3例 ,CAG示 1例 ;MRI示主动脉瓣上纤维嵴型狭窄 6例及发育不良型狭窄 1例。结论 :X线平片难以提供确定诊断的依据 ;超声心动图对主动脉瓣上狭窄的诊断有限 ;除主动脉瓣狭窄外 ,MRI可弥补超声心动图诊断中的不足 ,二者结合可达到术前诊断的目的 ,除特殊适应症外 ,无须行CAG检查。