主动脉壁内血肿的影像学诊断

目的 分析总结主动脉壁内血肿(AIH)的影像学特点。资料与方法 回顾8例影像学资料完整的AIH病例，分析其胸部X线平片、CT、MRI及血管造影特点。结果 8例AIH，1例累及升主动脉根部至腹主动脉远端，1例累及主动脉弓及降主动脉，6例累及降主动脉和／或腹主动脉，其中2例为降主动脉近中段动脉粥样硬化斑块穿通溃疡(PAU)形成局部AIH。胸部X线平片、增强CT、MRI及血管造影均可见阳性征象，CT、MRI直接观察到病变程度及累及的范围。结论 CT和MRI是确诊AIH的最主要检查手段。     

Penetrating aortic ulcers: diagnosis with MR imaging

The authors studied seven patients with penetrating aortic ulcers with use of magnetic resonance (MR) imaging. All patients were evaluated for acute chest symptoms, and the presence of aortic ulcers was confirmed by means of angiography in all seven patients. Five patients also underwent computed tomography (CT). Three patients underwent surgical repair of the thoracic aorta. MR findings included intramural hematoma and focal aortic wall ulceration in four patients, focal ulceration in one, focal intramural hematoma in one, and focal intramural hematoma with rupture in one. The diagnosis of intramural hematoma was made by the detection of increased signal intensity on T1- and T2-weighted MR images. MR imaging was superior to angiography in depicting the extent of intramural thrombus, although one ulceration diagnosed at angiography was missed at MR imaging. MR imaging was superior to CT in differentiating acute intramural hematoma from atherosclerotic plaque and chronic intraluminal thrombus, although it did not depict displaced intimal calcification in one patient with extensive intramural hematoma.     

Computed tomography evaluation of traumatic rupture of the thoracic aorta: an outcome study.

OBJECTIVE: [corrected] To assess the long-term outcome of blunt trauma patients with suspected thoracic aortic or great vessel injury that was evaluated with contrast-enhanced chest computed tomography (CT). METHODS: We studied the outcome of 278 consecutive patients who received contrast-enhanced CT for blunt chest trauma with computerized searches of the regional trauma database, hospital medical records, universal government medical coverage plan billing records, and regional vital statistics databases. Data retrieved included patient demographics, mechanism of injury, status of the aorta and proximal great vessels at contrast-enhanced CT, hospital discharge diagnoses, and outpatient procedural billings with specific attention to aortic or great vessel injury. Median follow-up was 615 days following the traumatic event. RESULTS: Six subjects demonstrated direct signs of aortic or proximal great vessel injury on contrast-enhanced chest CT, as follows: aortic pseudoaneurysm and intimal flap (n = 4), carotid artery dissection (n = 1), and aortic dissection (n = 1). All were surgically treated, except the patient with aortic dissection, who was treated medically. In the other subjects, contrast-enhanced CT was negative (n = 230) or showed isolated mediastinal hematoma (n = 42). The computerized searches of the medical databases showed that none of these 272 subjects had procedures for, or died from, aortic or great vessel injury during the follow-up period. CONCLUSION: Computerized searches of medical databases found no evidence of missed thoracic aortic or proximal great vessel injury in blunt trauma patients who were evaluated with contrast-enhanced chest CT.     

Radiologic evaluation of penetrating aortic atherosclerotic ulcer

Patients with penetrating atherosclerotic ulcers of the aorta present with back or chest pain that mimics classic aortic dissection. The pathologic findings, however, are distinctly different from those of aortic dissection in that an atherosclerotic lesion with ulceration penetrates into the internal elastic lamina, allowing hematoma formation within the media of the aortic wall. This may lead to false aneurysm or, rarely, transmural rupture of the aorta. Imaging findings of penetrating aortic atherosclerotic ulcers are also different from those of classic aortic dissection. We have found computed tomography to be especially useful in differentiating between these entities and present several illustrative cases.     

Infected aortic aneurysms: imaging findings

PURPOSE: To determine the imaging characteristics of infected aortic aneurysms. MATERIALS AND METHODS: Review of records of patients with surgical and/or microbiologic proof of infected aortic aneurysm obtained over a 25-year period revealed 31 aneurysms in 29 patients. This study included 21 men and eight women (mean age, 70 years). One radiologist reviewed 28 computed tomographic (CT) studies (22 patients underwent CT once and three patients underwent CT twice), 12 arteriograms (12 patients underwent arteriography once), eight nuclear medicine studies (six patients underwent nuclear medicine imaging once and one patient underwent nuclear medicine imaging twice), and three magnetic resonance (MR) studies (three patients underwent MR imaging once). Features evaluated included aneurysm size, shape, and location; branch involvement; aortic wall calcification; gas; radiotracer uptake on nuclear medicine studies; and periaortic and associated findings. The location of infected aortic aneurysms was compared with that of arteriosclerotic aneurysms. RESULTS: Aneurysms were located in the ascending aorta (n = 2, 6%), descending thoracic aorta (n = 7, 23%), thoracoabdominal aorta (n = 6, 19%), paravisceral aorta (n = 2, 6%), juxtarenal aorta (n = 3, 10%), infrarenal aorta (n = 10, 32%), and renal artery (n = 1, 3%). Two patients had two infected aortic aneurysms. CT revealed 25 saccular (93%) and two fusiform (7%) aneurysms with a mean diameter at initial discovery of 5.4 cm (range, 1-11 cm). Paraaortic soft-tissue mass, stranding, and/or fluid was present in 13 (48%) of 27 aneurysms, and early periaortic edema with rapid aneurysm progression and development was present in three (100%) patients with sequential studies. Other findings included adjacent vertebral body destruction with psoas muscle abscess (n = 1, 4%), kidney infarct (n = 1, 4%), absence of calcification in the aortic wall (n = 2, 7%), and periaortic gas (n = 2, 7%). Angiography showed 13 saccular aneurysms with lobulated contour in 10 (77%). Nuclear medicine imaging showed increased activity consistent with infection in six (86%) of seven aneurysms. MR imaging showed three saccular aneurysms. Adjacent abnormal vertebral body marrow signal intensity was seen in one (33%) of three patients. CONCLUSION: Saccular aneurysms (especially those with lobulated contour) with rapid expansion or development and adjacent mass, stranding, and/or fluid in an unusual location are highly suspicious for an infected aneurysm.     

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。     

16层螺旋CT血管成像技术在主动脉夹层中的临床价值

目的:探讨16层CT血管成像在主动脉夹层的诊断和临床治疗中的应用价值。方法:27例主动脉夹层患者均行16层CT胸腹联合平扫和增强扫描,采用多平面重组(MPR)、最大密度投影(MIP)、容积再现(VR)及表面遮盖显示(SSD)等后处理方法,重点观察和评价主动脉夹层的真假腔、内膜片、内膜破口以及重要分支血管的受累情况。结果:原始横轴位图像对病变信息的存储最为可靠;不同的重组方式所得图像有不同的显示特点;27例均很好地显示了主动脉全程及其分支,显示真、假腔27例(100%)、显示内膜片(100%)、内膜破口24例(88.9%)、假腔内血栓形成9例(30%)。结论:16层螺旋CT血管成像可以全面显示主动脉夹层的病变和解剖细节,在主动脉夹层的诊断和临床治疗中有重要的临床应用价值。     

Primary Stenting of Focal Atherosclerotic Infrarenal Aortic Stenoses: Long-Term Results in 13 Patients and a Literature Review

We conducted this study to investigate the value of primary stent implantation for the endovascular treatment of focal atherosclerotic stenoses of the infrarenal abdominal aorta. The data of 13 patients with a localized complex infrarenal aortic stenosis who underwent primary stenting was retrospectively evaluated. The patients (6 females, 7 males) had a mean age of 57.3 ± 9.1 years (mean ± SD). In all patients, the aortic diameter was measured on CT sections, and a self-expanding endoprosthesis was primarily implanted followed by dilatation with single or double balloons. In 3 patients, additional distal stenoses were also endovascularly treated. The procedure was technically successful in all patients. No complications occurred except for 2 minor groin hematomas. During the 43 ± 23 months (mean ± SD) follow-up (range: 12–96 months), all stented aortic segments remained patent. Clinical patency was lost in 4 patients, which was due to atherosclerosis or restenosis distal to the aorta. In view of the excellent early and long-term results, we believe that primary stenting should be considered the first line treatment in properly selected patients with focal atherosclerotic infrarenal stenoses of the abdominal aorta.     

Aortobronchopulmonary fistula complicating aortic aneurysm: diagnosis in four cases

Aortobronchopulmonary fistula, a fistulous connection between the aorta and lung, is uniformly fatal in untreated cases. However, with early recognition and surgery, the survival rate exceeds 80%. We have had four patients with aortobronchopulmonary fistula, all of which resulted from thoracic aortic aneurysms (two after grafting of thoracic aortic aneurysms, one mycotic, one atherosclerotic). All four patients presented with hemoptysis. All four had a chest radiograph, which in two showed the aneurysm and in three showed airspace disease adjacent to the aorta. The aneurysm was shown by CT in one of two patients and by aortography in two of three patients. Neither CT nor aortography showed the fistula. Aortobronchopulmonary fistula was proved by surgery in two of the patients and by autopsy in the other two. A high index of suspicion is necessary to make the diagnosis of aortobronchopulmonary fistula. The diagnosis should be considered in patients who have minor or major hemoptysis, with either coexisting thoracic aortic aneurysms or history of thoracic aneurysm repair.     

Acute non-opacified dissection of the ascending thoracic aorta--significance of retrograde dissection and re-dissection]

Thirteen cases of acute aortic dissection with non-opacified false lumen of the ascending aorta were examined by CT and other imaging modalities. On the basis of the initial CT findings, these cases were classified into two types; one was pure non-opacified dissection not associated with opacified false lumen (Type N, n = 7), the other was non-opacified dissection of the ascending aorta associated with opacified false lumen of the following aorta (Type N+O, n = 6). On examining the relation between the entry site and the false lumen in Type N+O, the dissection of the ascending aorta was considered to be retrograde. Retrograde dissection seemed to be an important factor in the development of the non-opacified dissection of the ascending aorta. During the follow-up period, re-dissection in the ascending aorta occurred in four of the 13 cases (Type N = 3, Type N+O = 1). The re-dissection occurred within the first four weeks in all of them, and the diagnosis of re-dissection was possible at its early stage. In one case, ulcerlike projection (ULP) was detected by aortography. In another case, ULP was identified by cine-MR imaging. Contrast CT also revealed enlargement and small opacification of the false lumen. In two other cases, similar CT findings were observed. Three of the four patients recovered by surgical treatment. One died the day after the diagnosis of re-dissection. Early diagnosis and earliest possible surgical intervention for re-dissection were considered necessary to save the patients with re-dissected false lumen in the ascending aorta. Close observations with several imaging modalities, mainly CT examination, should be paid in the patients with non-opacified dissection of the ascending aorta for at least four weeks after the onset of dissection.     

Chest radiography in acute aortic syndrome: pearls and pitfalls

Acute aortic syndrome is a group of life-threatening diseases of the thoracic aorta that usually present to the emergency department. It includes aortic dissection, aortic intramural hematoma, and penetrating aortic ulcer. Rare aortic pathologies of aorto-esophageal fistula and mycotic aneurysm may also be included in this list. All these conditions require urgent treatment with complex clinical care and management. Most patients who present with chest pain are evaluated with a chest radiograph in the emergency department. It is important that maximum diagnostic information is extracted from the chest radiograph as certain signs on the chest radiograph are extremely useful in pointing towards the diagnosis of acute aortic syndrome.     

Bronchopulmonary sequestration: CT assessment

Computed tomographic (CT) scans of 24 bronchopulmonary sequestrations in 23 patients were reviewed. Seventeen sequestrations were diagnosed at surgery, three at angiography, and four on the basis of radiographic or CT findings combined with appropriate history. Sixteen sequestrations were intralobar, and eight were extralobar; 21 were posterobasal. Seventeen occurred on the left side and seven on the right. Anomalous systemic arterial supply was demonstrated by CT in 16 sequestrations. In the others, a systemic artery was not shown, presumably because of unfavorable orientation or small size of the vessel. The lung abnormalities shown by CT were classified into three types: A = cysts containing air or fluid (n = 8), or soft-tissue masses (n = 2); B = emphysematous lung surrounding cysts, and/or soft-tissue nodules (n = 13); and C = lung hypervascularity (n = 2). In only three cases did the chest radiograph show the emphysematous lung tissue. Such emphysematous lung has rarely before been reported as a CT finding, and lung hypervascularity has not, to the authors' knowledge, been reported. The authors conclude that CT can be helpful in the diagnosis and evaluation of bronchopulmonary sequestration. Characteristic manifestations are (a) a complex lesion containing solid or fluid components combined with emphysematous lung or (b) any basal lesion supplied by a systemic artery.     

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.     

Pulmonary blastoma: radiologic findings in five patients

PURPOSE: To determine the radiologic findings of pulmonary blastoma on chest radiograph and CT. MATERIALS AND METHODS: Chest radiographs and CT scans of five patients with pathologically proven pulmonary blastoma were retrospectively evaluated and radiologic findings were correlated with histopathologic findings. RESULTS: On chest radiograph, the pulmonary blastoma manifested as a solitary parenchymal mass (n = 2), a solitary parenchymal nodule (n = 1), hilar bulging with fingerlike parenchymal opacities (n = 1), or opacification of hemithorax (n = 1). On CT, the pulmonary blastoma manifested as a solitary parenchymal mass (n = 2), a solitary parenchymal nodule (n = 1), an endobronchial mass with postobstructive pneumonitis (n = 1), or a parenchymal mass with multiple subpleural masses and pleural effusion (n = 1). CONCLUSION: Pulmonary blastomas most commonly manifested as a solitary parenchymal mass on chest radiograph and CT. These radiologic features are nonspecific and many primary or metastatic tumors of the lung could be included in differential diagnosis.     

Diagnostic accuracy of mediastinal width measurement on posteroanterior and anteroposterior chest radiographs in the depiction of acute nontraumatic thoracic aortic dissection

We aimed to explore the diagnostic accuracy of various mediastinal measurements in determining acute nontraumatic thoracic aortic dissection with respect to posteroanterior (PA) and anteroposterior (AP) chest radiographs, which had received little attention so far. We retrospectively reviewed 100 patients (50 PA and 50 AP chest radiographs) with confirmed acute thoracic aortic dissection and 120 patients (60 PA and 60 AP chest radiographs) with confirmed normal aorta. Those who had prior history of trauma or aortic disease were excluded. The maximal mediastinal width (MW) and maximal left mediastinal width (LMW) were measured by two independent radiologists and the mediastinal width ratio (MWR) was calculated. Statistical analysis was then performed with independent sample t test. PA projection was significantly more accurate than AP projection, achieving higher sensitivity and specificity. LMW and MW were the most powerful parameters on PA and AP chest radiographs, respectively. The optimal cutoff levels were LMW?=?4.95 cm (sensitivity, 90?%; specificity, 90?%) and MW?=?7.45 cm (sensitivity, 90?%; specificity, 88.3?%) for PA projection and LMW?=?5.45 cm (sensitivity, 76?%; specificity, 65?%) and MW?=?8.65 cm (sensitivity, 72?%; specificity, 80?%) for AP projection. MWR was found less useful and less reliable. The use of LMW alone in PA film would allow more accurate prediction of aortic dissection. PA chest radiograph has a higher diagnostic accuracy when compared with AP chest radiograph, with negative PA chest radiograph showing less probability for aortic dissection. Lower threshold for proceeding to computed tomography aortogram is recommended however, especially in the elderly and patients with widened mediastinum on AP chest radiograph.     

Traumatic rupture of the thoracic aorta. A review of 49 cases

We examined retrospectively the chest radiograph of forty nine patients with angiographically proven aortic ruptures. The plain film findings found most consistently were a wide mediastinum (69.5%), partial obliteration of the descending aorta (67.3%), left apical cap (65.3%), downward displacement of the left main bronchus (65.3%), tracheal deviation to the right (63.2%), obscuration of the aortic arch (55.1%), right paratracheal stripe thickening (53%) and nasogastric tube deviation to the right (50%). We also examined 113 sequential aortograms performed after thoracic trauma over 3 years, to determine the positive rate in our series; 14 studies were positive for a rate of 12.4%. No single case of proved ruptured aorta with a normal chest radiograph was detected.     

Summer-type hypersensitivity pneumonitis: comparison of high-resolution CT and plain radiographic findings.

Summer-type hypersensitivity pneumonitis is an immunologic disease that occurs only in Japan. It is a form of hypersensitivity pneumonitis in which the clinical symptoms appear in the summer and subside spontaneously in mid autumn. The purpose of our study was to determine the CT findings in this condition, to compare the CT findings with those on chest radiographs, and to assess the variations in the CT findings over time. Accordingly, high-resolution CT scans and chest radiographs of 15 patients with summer-type hypersensitivity pneumonitis were retrospectively studied. Seven patients had sequential CT examinations 18-37 days apart. The CT scans and chest radiographs were reviewed by two observers independently. CT findings included diffuse micronodules (n = 15), slightly elevated lung density (n = 13), and patchy air-space consolidation (n = 13). In one patient, the findings on a chest radiograph were normal, while CT showed parenchymal abnormalities. In two cases, follow-up CT showed micronodular abnormalities after findings on the chest radiograph had returned to normal. Our results show that high-resolution CT findings of summer-type hypersensitivity pneumonitis include pulmonary micronodules, increased lung density, and air-space consolidation. High-resolution CT appears to be more useful than plain chest radiographs in the evaluation of pulmonary parenchymal abnormalities in this condition.     

外伤性主动脉夹层的CT诊断(附2例报告)

目的：探讨外伤性主动脉夹层的早期CT表现。方法：回顾性分析在我院漏诊及确诊的外伤性主动脉夹层的CT表现。2例中1例行3次CT平扫,1例行CT平扫和增强扫描。结果：2例均为DeBakeyIU型主动脉夹层,1例3次CT平扫示降主动脉管腔进行性增宽,伴双侧胸腔积液;此例因漏诊,患者于2周后死亡。另1例CT平扫示降主动脉增粗,CT增强扫描明确诊断,主要表现为降主动脉扩张,可见真腔、假腔及内膜线;此例患者行支架植入术后,患者预后良好。结论：对于胸部外伤患者,CT平扫时应注意观察主动脉的直径,如果降主动脉增粗、尤其是进行性增粗时,应考虑主动脉夹层的可能。     

Pulmonary nodule simulated on the lateral chest radiograph by branches of the aortic arch

A prospective study of 500 lateral radiographs of the chest showed a nodular opacity superimposed on the trachea above the aortic arch in 15 patients (3%). Because no abnormalities were identified on the posteroanterior radiograph or on CT scans, we assume that this pseudonodule is produced by branches of the aorta. In all cases, CT showed that the left subclavian artery or the innominate artery-right subclavian complex protruded into the lung.     

Concurrent dissections of ascending aorta and right coronary artery during primary coronary angioplasty

We present a case of dissection in ascending aorta (AA) accompanying dissection of the right coronary artery (RCA) during transfemoral primary coronary angioplasty (PCA) for acute inferior myocardial infarction (MI). To our best knowledge, this is the first case of dissection both in AA and RCA during angioplasty for acute MI. The dissection in RCA was caused by balloon inflation during PCA. Most probably, an angiographically invisible retro-dissection in RCA resulted in the dissection in AA. A computed tomography (CT) confirmed the diagnosis of aortic dissection that was restrained in AA. The patient was treated conservatively. Five days after the event, a control CT demonstrated that the false lumen in AA disappeared and the dissection was healed entirely.