Abdominal CT angiography before surgery as a predictor of postoperative death in acute aortic dissection

OBJECTIVE: The purpose of our study was to search for a relationship between postoperative death in acute aortic dissection and abdominal helical CT findings before surgery. MATERIALS AND METHODS: We retrospectively included 48 patients admitted to our institution for emergent surgery of acute aortic dissection diagnosed with helical CT angiography. We recorded postoperative deaths and analyzed abdominal helical CT vessels and parenchymal abnormalities, including the presence of dissected abdominal aortic branches, a compressed aortic lumen, and low enhancement of the parenchyma in abdominal organs. RESULTS: Among the 48 patients, 11 died after surgery. Postoperative death occurred in one of five patients with low enhancement of the parenchyma in one abdominal organ and in seven of eight patients with low enhancement of the parenchyma in at least two abdominal organs. The postoperative death rates strongly correlated with the number of low-enhanced abdominal organs per patient (p < 0.00005) but did not correlate with the number of dissected abdominal aortic branches. CONCLUSION: The rate of abdominal organs with low enhancement of the parenchyma seen on CT before surgery is a strong factor in outcome in patients with acute aortic dissection. Additional analysis of low enhancement of the parenchyma in abdominal organs on CT might be a useful tool to detect, before surgery, patients at risk of postoperative death.     

Clinical application of single shot GRE-EPI as non-enhanced MRA (EPI-MRA) for aortic aneurysm and dissection

We investigated the usefulness of single shot gradient echo type echo planar imaging (GRE-EPI) as magnetic resonance angiography (MRA) for the diagnosis of aortic aneurysm and dissection. This technique can detect blood flow signals in several tenths of a milliseconds without the need for contrast medium, breath-holding, or electrocardiographic (ECG) gating. By scanning approximately 20 frames in the coronal plane, three-dimensional (3D) imaging can be achieved by maximum intensity projection (MIP) at different angles. Three radiologists evaluated the ability of this single shot GRE-EPI as non-enhanced MRA (EPI-MRA) to diagnose aortic aneurysm and dissection. The examined lesions consisted of three cases of thoracic aortic aneurysm, seven of abdominal aortic aneurysm and eight of aortic dissection with a total of 15 involved aorta. In all patients with aortic aneurysm, EPI enabled detection and diagnosis of the aneurysm. However, the size of the lesion and relationship with major branches were determined only in the abdominal aorta, and could not be determined precisely in thoracic lesions. Similar results were obtained for patients with aortic dissection. The technique visualized the intimal flap and enabled determination of the extent of dissection in the abdominal aorta. In the thoracic aorta, serious magnetic susceptibility artifacts caused image distortion, and as a result only the dissection could be detected and diagnosed. No entry site was detected at either the abdominal or thoracic aorta. These results suggest that EPI-MRA may have a clinical potential for screening patients with acute aortic disease who cannot undergo physical restraint for scanning.     

CT diagnosis of acute aortic dissection; clinical importance of acute aortic dissection with non-opacified false lumen

Sixteen (47.5%) of 35 patients with acute aortic dissection showed a non-opacified crescent in the aorta on an initial contrast CT. Seven of these 16 patients underwent cineangiography soon after the initial CT, and in all 7 patients, neither an intimal tear nor an intimal flap was obtained. All but one of above 16 patients were followed by CT. Mean duration of follow-up was 9.6 months. In 10 of 15 patients with non-opacified false lumen, the false lumen remained non-opacified until the last examination. Moreover, in 6 of these 10 patients, the false lumen shrunk, and in the other 3, it disappeared completely on follow-up CT. On the other hand, in remaining 5 of these 15 patients who were initially diagnosed to have non-opacified false lumen, the false lumen became opacified and enlarged in size on follow-up CT performed in the first 14 weeks. Moreover, in 4 of these 5 patients, the false lumen became opacified in the only first 6 weeks. No matter how intensive care should be paid at least for the first 6 weeks, it seems that patients with aortic dissection which have non-opacified false lumen had good prognosis in comparison to patients with ordinary aortic dissections which have opacified false lumen. We believe aortic dissection with non-opacified false lumen may consist of two type of aortic dissection, one has no intimal tear, the other has some intimal tears and a thrombosed false lumen. In conclusion, CT is the most useful modality in diagnosing acute aortic dissection. The reasons are the incidence of acute aortic dissection with non-opacified false lumen was high, patients with non-opacified false lumen had good prognosis, and it was difficult to diagnose aortic dissection with non-opacified false lumen by conventional cineangiography and/or DSA.     

Atypical presentation of dissection of the ascending aorta in young men with cystic medial necrosis: MR findings

Dissection of the ascending aorta is usually associated with severe chest and/or back pain. We describe three young men, with pathologically proven cystic medial necrosis, who presented with atypical clinical symptoms and ascending aortic dissection diagnosed by MR imaging and surgery. Patients with cystic medial necrosis and aortic dissection may not present with a classic acute chest pain syndrome.     

CT recognition of acute aortic dissection

Twenty-six patients with suspected acute aortic dissection were investigated using computed tomography (CT) as the primary mode of investigation. The diagnosis was controlled by aortography or surgery or both. There were no false-positive or false-negative studies using CT. Aortography was performed on 19 of the 21 patients with aortic dissection and was positive in each instance. However, in two illustrated cases, CT indicated proximal or type A aortic dissection, whereas the corresponding aortograms indicated distal or type B aortic dissection. In two of the 21 acute aortic dissections, only CT was performed, and in both instances surgical confirmation was obtained. The results suggest that CT is at least as accurate as aortography in the diagnosis of acute aortic dissection.     

彩超在诊断主动脉夹层中的应用

目的评价彩超诊断主动脉夹层的临床价值。方法采用HP—Image Point Hx和PH—HD11彩超，对2000年2月至2007年1月间诊断的21例主动脉夹层患者进行总结分析。结果19例主动脉夹层患者均经彩超确诊，2例可疑病例经尸检证实。结论彩超对主动脉夹层的诊断、治疗方案选择及预后判断具有重要的临床价值。     

主动脉夹层磁共振成像研究

本文对２３例经ＭＲ自旋回波序列和梯度回波序列诊断为主动脉夹层患者进行了研究，探讨了不同序列及不同体位对观察主动脉夹层内膜片、破口位置、分支血管受累情况、区分真腔和假腔的诊断价值。并分析了ＭＲＩ的局限性。作者认为，ＭＲＩ是诊断主动脉夹层首选和最好的诊断方法，对主动脉夹层的临床治疗具有非常重要的指导意义。     

Acute and chronic complications of aortic intramural hematoma on follow-up computed tomography: incidence and predictor analysis

OBJECTIVE: To ascertain the incidence of acute and chronic complications of aortic intramural hematoma (IMH) and to analyze the predictors of the development of each complication. MATERIALS AND METHODS: This retrospective study includes 107 consecutive patients diagnosed with aortic IMH by means of computed tomography (CT) during the period from January 1998 to December 2003 and followed up with serial CT examinations (median follow-up period, 320 days). There were 36 patients with type A and 71 with type B IMH. Initial and follow-up CT scans were reviewed, with special attention given to the development of complications, such as increase in the thickness of IMH, clinical and hemodynamic evolution requiring urgent surgery, and development of aortic dissection and/or aneurysm. If each complication developed within 30 days after the initial episode, we classified it as an acute complication; the others were classified as chronic complications. The time interval between the initial and the subsequent CT examination showing each complication was recorded. To identify the predictors of each complication, we analyzed the demographic and CT findings with regard to the following factors: age, sex, maximum thickness of the hematoma, maximum aortic diameter on initial CT examination, ulcerlike projection (ULP) on initial and follow-up CT examinations, and the degree of atherosclerosis. The Cox proportional hazards regression model with stepwise multivariate analyses was used to determine the significant predictors of each complication. RESULTS: Sixteen patients had acute complications consisting of aortic dissection (n = 7), aortic aneurysm (n = 6), and acute clinical and hemodynamic evolution requiring operation (n = 3). Three additional patients with aortic dissection (n = 1) and aneurysm (n = 2) underwent emergency surgery. Twenty-three patients with chronic complications had aortic dissection (n = 3), and aortic aneurysm (n = 20). Cox proportional hazards regression model revealed that the maximal diameter of involved aorta is the only significant predictor of the development of acute complications (P = 0.006), whereas the age (P = 0.040), type A IMH (P = 0.015), presence of ULP (P = 0.015), and newly developed ULP as revealed on follow-up CT examination (P = 0.032) were significant predictors of the development of chronic complications. With regard to the aortic dissection in 10 patients (9.3%; type A/B ratio, 5:5; median time interval, 34 days), Cox proportional hazards regression model revealed that the maximal thickness of the hematoma is the only significant predictor (P = 0.018). Twenty-one saccular and 5 fusiform aneurysms (24.3%) developed, as revealed on follow-up CT examinations (median time interval, 180 days). The presence of ULP (P = 0.030), type A (P = 0.038) and the maximal thickness of the hematoma (P = 0.017) were significant predictors for the development of an aneurysm. CONCLUSIONS: The maximum thickness of a hematoma on the initial CT is the significant factor predicting the development of aortic dissection and aortic aneurysm. Patients with type A IMH and ULP, as revealed by initial and short-term follow-up CT examinations, should be carefully followed up with subsequent CT examination to monitor the development of an aortic aneurysm, which is a relatively common chronic complication of IMH.     

Aortic dissection presenting as stroke with focal neurologic deficits: A case report

Aortic dissection is a relatively uncommon and potentially misdiagnosed disease. Early and accurate diagnosis and appropriate treatment are imperative for patient survival. In this case, we present a 55-year-old male who presented to the Emergency Department with severe abdominal pain and acute neurological deficits who was triaged for stroke protocol. After unexpected findings on physical examination, other diagnostic hypotheses were evaluated, culminating in the diagnosis of aortic dissection. The purpose of this article is to exemplify a patient who presents with noteworthy neurologic clinical features who ultimately was diagnosed with Type B aortic dissection, to help benefit the rapid diagnosis and subsequent treatment for future patients with similar presentations.     

Thoracic aortic disease: Spectrum of multidetector computed tomography imaging findings

The clinical presentation of diseases involving the thoracic aorta ranges from a large number of asymptomatic patients with clinically undetectable thoracic aortic aneurysm to patients with symptoms of severe chest pain as a result of acute aortic dissection. Thoracic aortic disease often remains undiagnosed until a life-threatening complication occurs or the disease is discovered serendipitously on imaging studies performed for other purposes. Multidetector row computed tomography (MDCT) imaging of the aorta is used to diagnose various acute and chronic conditions, including aortic aneurysms, aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, traumatic injury, rupture, inflammatory disorders, and congenital malformations. This review illustrates the wide range of MDCT imaging findings of thoracic aortic disease.     

Triple rule-out CT in the emergency department: protocols and spectrum of imaging findings

Triage decisions in patients suffering from acute chest pain remain a challenge. The patient’s history, initial cardiac enzyme levels, or initial electrocardiograms (ECG) often do not allow selecting the patients in whom further tests are needed. Numerous vascular and non-vascular chest problems, such as pulmonary embolism (PE), aortic dissection, or acute coronary syndrome, as well as pulmonary, pleural, or osseous lesions, must be taken into account. Nowadays, contrast-enhanced multi-detector-row computed tomography (CT) has replaced previous invasive diagnostic procedures and currently represents the imaging modality of choice when the clinical suspicion of PE or acute aortic syndrome is raised. At the same time, CT is capable of detecting a multitude of non-vascular causes of acute chest pain, such as pneumonia, pericarditis, or fractures. Recent technical advances in CT technology have also shown great advantages for non-invasive imaging of the coronary arteries. In patients with acute chest pain, the optimization of triage decisions and cost-effectiveness using cardiac CT in the emergency department have been repetitively demonstrated. Triple rule-out CT denominates an ECG-gated protocol that allows for the depiction of the pulmonary arteries, thoracic aorta, and coronary arteries within a single examination. This can be accomplished through the use of a dedicated contrast media administration regimen resulting in a simultaneous attenuation of the three vessel territories. This review is intended to demonstrate CT parameters and contrast media administration protocols for performing a triple rule-out CT and discusses radiation dose issues pertinent to the protocol. Typical life-threatening and non-life-threatening diseases causing acute chest pain are illustrated.     

Type B aortic dissection complicating renal artery angioplasty and stent placement

Percutaneous renal artery stent placement has been demonstrated to improve blood pressure control and stabilize renal function in patients with atherosclerotic renal artery disease. However, this procedure is not without risk of significant morbidity, and its effectiveness, as compared to alternative treatments, has not been adequately established. The authors report a case of acute type B aortic dissection complicating renal artery stent placement. The authors postulate that an intimal disruption occurred during initial balloon angioplasty, and that repeated application of radial, shear, and torque forces during stent placement may have extended the injury. The diagnosis of acute aortic dissection should be considered in patients with suggestive symptoms immediately after stent placement.     

Investigations of fatal causes of chest pain: case report and literature review

A case of fatal ascending aortic dissection (AAD) misdiagnosed as pulmonary embolism (PE) despite strong radiological evidence is described. The occurrence of this serious pathology is uncommon. Its prompt diagnosis and treatment are crucial. Anticoagulant therapy for pulmonary embolism should be withheld until acute aortic dissection is excluded definitively. A management approach to optimise the outcome of patients with chest pain in which ascending aortic dissection and/or pulmonary embolism are suspected is presented.     

Morphologic Outcome after Endovascular Treatment of Complicated Type B Aortic Dissection

PurposeTo investigate the long-term morphologic changes of the aorta after thoracic endovascular aortic repair (TEVAR) for acute complicated type B aortic dissection and to analyze whether these changes differed between DeBakey class IIIa and IIIb dissections.Materials and MethodsDuring the period 1999–2009, 58 patients with acute complicated type B aortic dissection were treated with TEVAR. Seven patients lacked follow-up data, leaving 51 patients—17 patients with DeBakey IIIa aortic dissection and 34 patients with DeBakey IIIa aortic dissection IIIb—for inclusion in the study. Computed tomography scans performed before and after TEVAR were evaluated. Maximum thoracic and abdominal aortic diameters and diameters of the true lumen and false lumen at the level of the maximum aortic diameter in the thorax and abdomen were analyzed as well as degree of thrombosis of the false lumen.ResultsThere was an overall significant reduction of the thoracic aortic diameter, increased true lumen diameter, and reduced false lumen diameter (P < .05). Total thrombosis of the false lumen, with or without reintervention, was seen in 53% of all patients, in 41% primarily and in 12% after reintervention. The IIIa group had a higher degree of total false lumen thrombosis. All patients in the IIIb group had total thrombosis of the false lumen along the stent graft.ConclusionsLong-term follow-up showed favorable aortic remodeling after TEVAR for acute complicated type B aortic dissection. Total thrombosis of the false lumen occurred more often in patients with DeBakey IIIa aortic dissection compared with patients with DeBakey IIIb aortic dissection.     

The value of narrow CT window settings in the recognition of subtle acute aortic intramural haematoma

Four patients with acute aortic intramural haematoma are presented. In all patients the typical crescentic hyperdense rim within the aortic wall was not obvious on unenhanced CT when reviewed on standard mediastinal windows, but the hyperdense crescentic rim was well seen on narrow window settings. The findings suggest that all patients with a typical clinical presentation of acute thoracic aortic dissection who do not have a classical dissection on contrast-enhanced CT or a hyperdense intramural haematoma on standard mediastinal settings, should have the non-contrast scans reviewed on narrow window settings.     

Helical CT in emergency radiology.

Today, a wide range of traumatic and nontraumatic emergency conditions are quickly and accurately diagnosed with helical computed tomography (CT). Many traditional emergency imaging procedures have been replaced with newer helical CT techniques that can be performed in less time and with greater accuracy, less patient discomfort, and decreased cost. The speed of helical technology permits CT examination of seriously ill patients in the emergency department, as well as patients who might not have been taken to CT previously because of the length of the examinations of the past. Also, helical technology permits multiple, sequential CT scans to be quickly obtained in the same patient, a great advance for the multiple-trauma patient. Higher quality CT examinations result from decreased respiratory misregistration, enhanced intravenous contrast material opacification of vascular structures and parenchymal organs, greater flexibility in image reconstruction, and improved multiplanar and three-dimensional reformations. This report summarizes the role and recommended protocols for the helical CT diagnosis of thoracic aortic trauma; aortic dissection; pulmonary embolism; acute conditions of the neck soft tissues; abdominal trauma; urinary tract stones; appendicitis; diverticulitis; abdominal aortic aneurysm; fractures of the face, spine, and extremities; and acute stroke.     

胸主动脉腔内修复术治疗急性Stanford B型主动脉夹层前后的生化指标变化

目的研究急性Stanford B型主动脉夹层患者行胸主动脉腔内修复术（TEVAR）前后相关实验指标变化情况,评估腔内治疗的近期效果。 方法筛选2012年11月—2013年11月我科收治并行TEVAR的急性Stanford B型主动脉夹层60例,分别检测其术前及术后生化指标白细胞总数、中性粒细胞、淋巴细胞、单核细胞、谷丙转氨酶、谷草转氨酶、尿素氮、肌酐、胱抑素C的变化情况。 结果60例患者TEVRA前后白细胞总数及中性粒细胞总数平均值均高于正常范围,术前及术后对比无明显差异（P>0.05）。TEVAR前谷丙转氨酶及谷草转氨酶平均值均高于正常范围,其中谷丙转氨酶升高占30%,谷草转氨酶升高占21.7%,TEVAR后谷丙转氨酶及谷草转氨酶明显低于术前（P <0.05）,其平均值下降至正常范围。TEVAR前尿素氮、肌酐及胱抑素C平均值均高于正常,其中尿素氮升高占31.7%,肌酐升高占30%,胱抑素C升高占35%,TEVAR后尿素氮及肌酐明显下降（P <0.05）,胱抑素C比术前降低不明显（P>0.05）。 结论TEVAR可以明显改善急性Stanford B型主动脉夹层患者的肝肾功能,对急性Stanford B型主动脉夹层近期效果良好,但远期效果还需大样本长期随访。     

主动脉不典型夹层的电子束CT诊断

目的 评价电子束CT（EBCT）在主动脉不典型夹层诊断中的临床应用。方法 1994年5月至2000年4月15000例EBCT检查中诊断主动脉夹层263例,其中25例为不典型夹层。男21例,女4例。全部患者均以主诉急性胸痛入院检查。采用Imatron 150-XP型EBCT扫描机,连续容积增强扫描,层厚3mm,扫描时间为0．1s。扫描范围自主动脉弓水平至左右髂动脉分叉处,共140层。结果 不典型夹层EBCT血管造影（EBCTA）：直接征象为:(1)25例主动脉壁均呈半月状或环状增厚,达5－23mm,平均15．3mm,无内膜破裂形成的双腔主动脉征象,CT值50－87HU,累及长度为2．5－49．0cm,平均16．3cm;（2）内膜钙化移位5例;（3）6例治疗后EBCT随访,管壁厚度呈动态变化。间接征象为：（1）主动脉壁增厚溃疡形成7例;（2）动脉粥样硬化性改变12例。上述征象结合临床急性胸痛病史,诊断可以成立。病变累及升主动脉（StanfordA型）6例;仅累及降主动脉（StanfordB型）19例。全部病例临床均采取保守治疗,其中6例EBCT复查,3个月至1年血肿吸收。结论 急诊胸痛鉴别诊断中EBCT对主动脉不典型夹层诊断是一种无创、安全、有效的诊断方法,且便于治疗后随诊观察。     

超声、MR、CT、X线诊断主动脉夹层的比较

目的：比较超声、MR、CT及X线对主动脉夹层的诊断价值。方法：2005—01～2008—09经手术病理证实的26例主动脉夹层患者,26例均经超声、X线检查,17例经MR及CT检查,重点观察超声主动脉声像,内膜有无撕裂及撕裂部位,真假腔血流情况,主动脉瓣有无受累及瓣膜反流情况、心包积液、左室收缩功能等。结果．26例超声诊断25例,其中12例为DeB—bakeyI型,占46．2％,5例为Ⅱ型,占19．2％,9例为Ⅲ型,占34．6％,I型最常见。19例中量以上主动脉瓣反流,7例少量主动脉瓣反流,9例少一中量心包积液。16例LVEF％及LVFS％降低。17例经MR及CT检查诊断15例,26例胸片提示主动脉增宽,心影增大。结论：超声可作为诊断主动脉夹层的首选检查项目。     

主动脉夹层的超声心动图诊断与磁共振影像诊断的比较

 目的探讨经胸超声心动图(TTE)、经食管超声心动图(TEE)对主动脉夹层诊断价值,并与磁共振影像(MRI)进行比较.方法对21例经手术证实的主动脉夹层患者影像资料进行分析,对照手术结果,评价超声心动图(CDE)诊断主动脉夹层及其并发症的准确性,并同磁共振影像(MRI)诊断结果进行比较.结果CDE、MRI对主动脉夹层的诊断率分别为95.2%、90.5%.CDE对诊断主动脉瓣损害,显示心腔扩大、心功能降低、心包腔积液等心脏整体情况优于MRI.MRI对内膜破口及主动脉分支受累的诊断优于CDE.结论CDE对主动脉夹层的诊断具有较高的临床应用价值,对主动脉夹层的诊断敏感性与MRI相似,联合应用TTE、TEE、MRI检查有利于全面估计疾病情况,从而为临床医生提供准确而全面的信息.