Stanford type A aortic dissection with pulmonary arterial intramural hematoma and pulmonary hemorrhage

A rare complication of a Stanford type A aortic dissection is extension along the pulmonary arteries. We present a case that shows main and right pulmonary artery intramural hematoma and pulmonary hemorrhage in an 80-year-old woman who presented with a type A Stanford aortic dissection. The 11-month follow-up multidetector CT angiogram for this patient showed that the right pulmonary artery had become aneurysmal.     

Vascular diseases of the thorax: evaluation with multidetector CT

The list of vascular diseases in the thorax has been narrowed to three, which are considered essential information for radiologists interpreting CT scans of the thorax: (1) aortic dissection and its variants, intramural hematoma and penetrating atherosclerotic ulcer; (2) acute pulmonary embolism; and (3) coronary artery disease. The spatial resolution of multidetector CT is such that CT has become the imaging modality of choice for aortic dissection and pulmonary embolism. This move away from angiography has transpired over the last decade; perhaps the next decade will see the same occur for evaluation of coronary artery disease.     

Suspected aortic dissection and other aortic disorders: multi-detector row CT in 373 cases in the emergency setting

PURPOSE: To retrospectively review the authors' experience with multi-detector row computed tomography (CT) for detection of aortic dissection in the emergency setting. MATERIALS AND METHODS: The investigation was institutional review board approved, did not require informed patient consent, and was HIPAA compliant. In 373 clinical evaluations in the emergency setting, 365 patients suspected of having aortic dissection and/or other aortic disorders underwent multidetector CT. Criteria for acute aortic disorder were confirmed by using surgical and pathologic diagnoses or findings at clinical follow-up and any subsequent imaging as the reference standard. Positive cases were characterized according to type of disorder interpreted. Resulting sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated by using two-way contingency tables. All cases found to be negative for acute aortic disorders were grouped according to alternative CT findings. RESULTS: Sixty-seven (18.0%) of the 373 cases were interpreted as positive for acute aortic disorder. One hundred twelve acute aortic disorders were identified in these 67 cases: 23 acute aortic dissections, 14 acute aortic intramural hematomas, 20 acute penetrating aortic ulcers, 44 new or enlarging aortic aneurysms, and 11 acute aortic ruptures. Three hundred five (81.8%) cases were interpreted as negative for acute aortic disorder. In 48 negative cases, multidetector CT depicted alternative findings that accounted for the clinical presentation. Of these, three included both acute aortic disorders and alternative findings, and 45 included only alternative findings. One (0.3%) case was indeterminate for acute aortic disorder. Overall, 112 findings were interpreted as positive for acute aortic disorder, an alternative finding, or both at CT. No interpretations were false-positive, one was false-negative, 67 were true-positive, and 304 were true-negative. Sensitivity, specificity, PPV, NPV, and accuracy were 99% (67 of 68), 100% (304 of 304), 100% (67 of 67), 99.7% (304 of 305), and 99.5% (371 of 373), respectively. CONCLUSION: The positivity rate for acute aortic dissection or other acute aortic disorder in 373 cases examined at multi-detector row CT was 18.0%.     

急性主动脉综合征高风险MDCT特征评估及研究进展

急性主动脉综合征(AAS)包括主动脉夹层、壁内血肿、穿透性主动脉溃疡、创伤性主动脉撕裂及不稳定的胸主动脉瘤,是一组病情进展迅速,具有较高病死率的病变。采用多层螺旋CT可对AAS高风险影像特征进行动态定量评估。综述各类病变的病理机制及典型CT表现,从病灶位置、大小、累及范围、有无并发症及随访中的变化等角度介绍AAS高风险影像特征,分析其中哪些征象可为临床选择治疗方案提供依据。     

Isolated interrupted aortic arch accompanied by type B aortic dissection and extensive collateral arteries diagnosed with MDCT angiography

Interrupted aortic arch (IAA) is a rare congenital cardiovascular condition. A patient with uncorrected IAA accompanied by rich collateral arteries can survive to adulthood asymptomatically. However, IAA complicated by aortic dissection is life threatening. Herein, we report a rare case of an isolated IAA accompanied by type B aortic dissection and extensive collateral arteries detected by multidetector computed tomography in a 38-year-old man. The imaging findings of the case are presented, and the utility of multidetector computed tomography in the evaluation of this condition is discussed.     

The many faces of aortic dissections: Beware of unusual presentations

Aortic dissection is gaining recognition in Western societies, and it is being diagnosed with increasing frequency. New diagnostic imaging modalities, longer life expectancy, as well as the increase in the number patients suffering from hypertension have all contributed to the growing awareness of aortic dissection. Nevertheless, as many as 30% of patients ultimately diagnosed with acute dissection are first thought to be suffering from something else. The increased availability and use of multidetector computed tomography has led to the incidental discovery of aortic dissection in very different settings. This article focuses on unusual presentations of painless aortic dissection. It is important for radiologists to remember that aortic dissections may present in different ways, not only as an acute, critical fatality but also with subtle, unusual signs and symptoms, which apparently do not seem to be strictly related to aortic diseases.     

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.     

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.     

Multidetector row CT diagnosis of aortocaval fistula complicating aortic aneurysm: a case report

Aortocaval fistula is a rare complication of abdominal aortic aneurysm involving less than 1% of all abdominal aortic aneurysms and causing severe hemodynamic derangements from a large left-to-right shunt; early diagnosis and repair results in improved morbidity and lower mortality but the diagnosis is difficult. We report a case of prompt diagnosis obtained with thoracoabdominal aortic multidetector row angio-CT as the first imaging procedure and allowing immediate surgical repair. Our report emphasizes the crucial role played by multidetector row CT as the first procedure in thoracoabdominal vascular emergencies.     

CT断层图像和三维重建在主动脉腔内隔绝术术前评估中的价值

目的比较CT断层图像和三维重建在主动脉腔内隔绝术术前评估中的价值。方法将接受主动脉腔内隔绝术的20例主动脉夹层瘤和12例腹主动脉瘤患者作为研究对象,术前分别在CT断层图像与三维重建图像上测量的各相关参数,与主动脉造影所测量的相同参数进行对照分析。结果CT断层图像上所测量的主动脉弓直径及各种长度指标均小于主动脉造影结果;夹层瘤近段主动脉直径及近端瘤颈直径、主动脉中段直径以及左右髂动脉直径均大于主动脉造影结果;三维重建所测量的上述各项参数与主动脉造影结果非常接近,并能清楚显示夹层分离的破裂口,而断层图像上不易发现破裂口;断层图像和三维重建在显示主动脉附壁血栓和测量最大瘤体直径方面优于主动脉造影。以三维重建测量为标准选择覆膜支架,所有患者均成功封闭瘤体。结论主动脉腔内隔绝术术前评估时应结合CT断层图像和三维重建图像综合分析,覆膜支架的选择应以三维重建测量结果为主。     

Useful CT findings for predicting the progression of aortic intramural hematoma to overt aortic dissection

PURPOSE: The purpose of this work was to assess useful CT findings for predicting the progression of aortic intramural hematoma to aortic dissection. METHOD: We analyzed the CT findings of 29 patients with aortic intramural hematoma with regard to the following: involved site, maximum thickness of hematoma, presence or absence of compression of true lumen, and pericardial and pleural effusion. CT findings were compared with those of the patients who progressed to aortic dissection (Group I) and those who did not (Group II). Each CT finding was evaluated with independent t test and Mann-Whitney U test (p < 0.05). RESULTS: Seven of 8 cases of Type A aortic intramural hematoma and 3 of 21 cases of Type B aortic intramural hematoma progressed to aortic dissection. The type of aortic intramural hematoma, maximum thickness of hematoma, compression of true lumen, and pericardial or pleural effusion were significantly different in Groups I and II. CONCLUSION: Type A aortic intramural hematoma, maximum thickness of hematoma, compression of true lumen, and pericardial or pleural effusion are the useful CT findings for predicting the progression of aortic intramural hematoma to aortic dissection.     

Aortic valve area assessment: multidetector CT compared with cine MR imaging and transthoracic and transesophageal echocardiography

PURPOSE: To prospectively compare the accuracy of multidetector computed tomographic (CT) measurements of the aortic valve area (AVA) with transesophageal echocardiography (TEE) and cine magnetic resonance (MR) measurements of this area for preoperative examination of patients undergoing cardiac surgery, with transthoracic echocardiography (TTE) as the reference standard. MATERIALS AND METHODS: After giving informed consent for the institutional review board-approved study protocol, 48 patients (33 men, 15 women; mean age, 62 years+/-13 [standard deviation]) with (n=27) or without (n=21) aortic stenosis underwent multidetector CT, cine MR, TTE, and TEE before undergoing cardiac surgery. AVAs derived with manual planimetry by using cine short-axis multidetector CT, MR, and TEE images obtained through the aortic valve were compared among each other and with AVAs measured by using continuity equation TTE at regression and Bland-Altman analyses. The diagnostic accuracy of multidetector CT for detection of aortic stenosis was compared with that of TTE by using kappa statistics and receiver operating characteristic curves. RESULTS: Multidetector CT-derived AVA correlated highly with MR-derived (r=0.98, P<.001), TEE-derived (r=0.98, P<.001), and TTE-derived (r=0.96, P<.001) AVA. Multidetector CT planimetry AVAs (mean AVA+/-standard deviation, 2.5 cm2+/-1.7) were not significantly different from MR planimetry (2.4 cm2+/-1.8, P>.99) or TEE planimetery (2.5 cm2+/-1.7, P=.21) AVAs, but they were significantly larger than TTE-derived AVAs (2.0 cm2+/-1.5, P<.001). With TTE as the reference standard, multidetector CT correctly (kappa=0.88, P<.001) depicted all 21 normal, six of eight mildly stenotic (AVA>or=1.2 cm2 and <2.0 cm2), seven of eight moderately stenotic (AVA>or= 0.8 cm2 and <1.2 cm2), and 10 of 11 severely stenotic (AVA<0.8 cm2) valves. It also correctly depicted all 14 bicuspid valves identified with TEE, eight of which were missed with TTE. CONCLUSION: Multidetector CT enables accurate noninvasive assessment of the AVA.     

A case report of a normal aorta misdiagnosed as type A dissection by modern multidetector computed tomography

Computed tomography (CT) is generally considered the investigation of choice to exclude acute aortic syndrome. We report an important potentially disastrous misdiagnosis using a modern 32 slice multidetector CT system.     

Acute traumatic aortic injury: imaging evaluation and management

Despite recent advances in prehospital care, multidetector computed tomographic (CT) technology, and rapid definitive therapy, trauma to the aorta continues to be a substantial source of morbidity and mortality in patients with blunt trauma. The imaging evaluation of acute aortic injuries has undergone radical change over the past decade, mostly due to the advent of multidetector CT. Regardless of recent technologic advances, imaging of the aorta in the trauma setting remains a multimodality imaging practice, and thus broad knowledge by the radiologist is essential. Likewise, the therapy for acute aortic injuries has changed substantially. Though open surgical repair continues to be the mainstay of therapy, percutaneous endovascular repair is becoming commonplace in many trauma centers. Here, the historical and current status of imaging and therapy of acute traumatic aortic injuries will be reviewed.     

Implementation of an aortic dissection CT protocol with clinical decision support aimed at decreasing radiation exposure by reducing routine abdominopelvic imaging

Patients suspected of having an acute aortic syndrome in the ED typically undergo CT of the chest/abdomen/pelvis. However, the overwhelming majority of these exams are negative. With the help of clinical decision support, we implemented a new radiologist monitored ‘aortic dissection screening protocol’ that forgoes routine abdominopelvic imaging in order to reduce radiation dose without compromising diagnostic accuracy. The purpose of the present study is to assess the performance of this protocol. A retrospective analysis was performed to study the effect of the dissection screening protocol on the diagnostic yield, radiation and contrast dose on a total of 835 ED patients who underwent CT scans for suspected aortic dissection over a 48-week study period immediately before and after implementation of the protocol. 3.4% (28/835) of examinations were positive for an acute aortic syndrome over the 48-week study period with no difference in positivity before and after implementation of the ‘aortic dissection screening’ protocol, 3.0% vs. 3.7%, respectively (p = 0.57). There was a 14.6% reduction in median radiation dose and a 16% decrease in contrast volume utilization for the total ED population who underwent CT for aortic dissection using any protocol in the period after implementation of the ‘aortic dissection screening’ protocol. Aortic dissection CT in the ED is negative in the overwhelming majority of cases. A monitored ‘aortic dissection screening’ protocol that initially images the chest only significantly reduced contrast and radiation dose without reducing diagnostic accuracy for ED patients who underwent CT for aortic dissection.     

Disección aislada y espontánea de arterias viscerales

We present the cases of two men with isolated spontaneous dissection of visceral arteries diagnosed by multidetector CT. In the first patient, dissection of the celiac trunk was associated with periarterial changes. In the second patient, dissection of the superior mesenteric artery was associated with stenosis at the root of the celiac trunk. Both patients presented with acute pain, which was more intense and longer lasting in the first patient. Aortic dissection was suspected clinically in both patients.     

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.     

Chest CT scanning for clinical suspected thoracic aortic dissection: beware the alternate diagnosis

The aim of the study was retrospectively to evaluate the spectrum of chest diseases in patients presenting with clinical suspicion of thoracic aortic dissection in the emergency department. We performed a retrospective medical records review of 86 men and 44 women (ages ranging between 23 and 106 years) with clinically suspected aortic dissection, for CT scan findings and final clinical diagnoses dating between January 1996 and September 2001. All images were obtained by using a standard protocol for aortic dissection. We found aortic dissection in 32 patients (24.6%), 22 of which were Stanford classification type A and 10 Stanford type B. In 70 patients (53.9%), chest pain could not be explained by the CT scan findings. However, in 28 patients (21.5%), CT scanning did reveal an alternate diagnosis that, along with the clinical impression, probably explained the patients' presenting symptoms, including: hiatal hernia (7), pneumonia (5), intrathoracic mass (4), pericardial effusion/hemopericardium (3), esophageal mass/rupture (2), aortic aneurysm without dissection (2), pulmonary embolism (2), pleural effusion (1), aortic rupture (1), and pancreatitis (1). In cases where there is clinical suspicion of aortic dissection, CT scan findings of an alternate diagnosis for the presenting symptoms are only slightly less common than the finding of aortic dissection itself. Although the spectrum of findings will vary depending upon your patient population, beware the alternate diagnosis. Electronic Publication     

Multidetector CT angiography in spontaneous popliteal artery dissection

Primary dissection of the femoropopliteal or popliteal arteries is rare in the absence of involvement of the aorta or aneurysmal arterial changes. In this report, we present multidetector CT angiography findings of a case of a spontaneous nonaneurysmal dissection limited to the left popliteal artery in an otherwise healthy 40-year-old woman.     

Duplicated right coronary artery: multidetector CT angiographic findings

Multidetector CT is becoming an alternative method for the diagnosis of coronary artery anomalies. We present the multidetector coronary CT angiography findings from a patient with right coronary artery duplication. Two separate right coronary arteries originating from the right aortic sinus were observed. Their anatomical course was well depicted, and atherosclerosis was excluded based on the CT angiography findings.