Chronic pulmonary thromboembolism diagnosed on the basis of characteristic mosaic patterns on lung computed tomograms]

We report on a 59-year-old woman who presented with characteristic findings on lung computed tomographic (CT) scans and was therefore suspected to have chronic pulmonary thromboembolism. She visited our hospital because of worsening exertional dyspnea over the preceding year, and because she was dissatisfied with an earlier diagnosis made by another institution. Chest roentgenograms disclosed nonhomogeneous hyperlucency in both lungs associated with linear and bundle shadows, dullness of the right costophrenic angle, and dilatation of the descending branch of the right pulmonary artery. The patient experienced moderate hypoxemia even at rest. Pulmonary function tests demonstrated a restrictive ventilatory pattern associated with reduced diffusion capacity. The lung CT scans disclosed a mosaic pattern of attenuation in the lung parenchyma, which probably reflected scattered areas of low perfusion. The unique characteristics of such CT findings drew our attention to chronic pulmonary thromboembolism as a possible diagnosis. We eventually confirmed the diagnosis on the basis of enhanced CT scans, pulmonary perfusion and ventilation scintigrams, and digital subtraction angiography. In our view, chronic pulmonary thromboembolism should be kept in mind as a possible differential diagnosis of the mosaic patterns of attenuation on lung CT scans.     

Pulmonary artery sarcoma mimicking pulmonary thromboembolism

A 30 years old male patient was referred to our hospital with a diagnosis of pulmonary thromboembolism due to thorax-computerized tomography (CT) angiography, revealing a thrombus totally occluding left main pulmonary artery. The lesion was evaluated as tumoural mass. Positron emission tomography (PET)-CT revealed pathologic uptake at pulmonary artery mass. Due to localization of tumour, left pneumonectomy was performed. The pathological diagnosis revealed to be pulmonary artery sarcoma. The patient was presented because pulmonary artery sarcomas are very rare tumors and can mimick pulmonary thromboembolism. The true prevalence is underestimated as many pulmonary artery sarcomas are misdiagnosed as pulmonary thromboembolism. PET-CT may help to make a differential diagnosis.     

急性非大面积肺血栓栓塞症9例随访分析

目的探讨9例急性非大面积肺血栓栓塞症（PTE）患者的临床特点、抗凝治疗3月或6月的转归。方法分析9例经多排螺旋CT肺动脉造影（CTPA）确诊的急性非大面积PTE患者的临床特点,对于首次发作伴随可去除危险因素（如手术、长期制动、长途乘车、长时间服用糖皮质激素等）的患者抗凝治疗3月,对于特发性或存在恶性肿瘤等持续性危险因素的患者抗凝治疗6月,在抗凝治疗期间监测国际标准化比值（INR）,使其稳定在2.0～3.0,且分别自抗凝治疗起随访6月和9月。结果 1例（11.1%）6月抗凝治疗组患者死亡（死于胆囊癌晚期所致全身衰竭）,8例（88.9%）3月抗凝治疗组患者均痊愈,随访期间未新发血栓。结论对于首次发作的伴随可去除危险因素的急性非大面积PTE患者选择抗凝治疗3月是安全有效的,血清D-二聚体是急性PTE可靠的初筛检查,多排螺旋CT肺动脉造影为可靠的确诊急性肺栓塞（PE）的检查。     

以晕厥就诊的肺血栓栓塞症12例临床分析

目的观察急性肺血栓栓塞症（PTE）合并晕厥时的临床表现及疾病严重度判定。方法回顾性分析2004年4月～2008年12月以晕厥就诊的12例急性PTE患者临床特点,心脏超声、CT肺动脉造影检查,治疗后14d～20d进行临床疗效评价。结果 12例出现晕厥的急性PTE患者中以大面积PTE为主,CT肺动脉造影（CTPA）显示,PTE伴晕厥者有75%累及中央肺动脉。结论 PTE伴晕厥者多有血流动力学异常或右心功能障碍,肺血管堵塞面积较大,容易发生病情恶化。     

Imaging of pulmonary thromboembolism

Pulmonary thromboembolism usually results from deep venous thrombi originating in the lower extremities. Therefore, imaging of venous thromboembolism includes evaluation of the pulmonary arteries and the deep veins of the lower extremities. The introduction of helical CT and multidetector row CT into daily use has enabled direct visualization of pulmonary arteries. CT venography, performed 3 minutes after CT pulmonary angiography (without additional contrast administration), adds the ability to evaluate the veins of the lower extremities and pelvis. The modalities currently used in the diagnostic workup of venous thromboembolic disease and their advantages and disadvantages are discussed in this article.     

Indirect CT venography following CT pulmonary angiography: spectrum of CT findings

SUMMARY: Pulmonary embolism (PE) and deep venous thrombosis (DVT) represent two manifestations of the same syndrome, venous thromboembolism. Contrast-enhanced computed tomography (CT) angiography is a practical, efficient alternative to conventional imaging for PE. Following the pulmonary examination, the inferior vena cava (IVC) and the iliac, femoral, and popliteal veins can be studied with CT without additional intravenous contrast administration. Indirect CT venography (CTV) after CT pulmonary angiography (CTPA) simplifies and shortens venous thromboembolism work-up. Initial studies indicate that CTV is comparable to ultrasound in the evaluation of femoral/popliteal DVT. CTV has the advantage of evaluating the iliac veins and inferior vena cava, vessels poorly seen on sonography and venography. Combining CTV with CTPA increases confidence in withholding treatment when results for both the pulmonary arteries and leg veins are negative and increases the diagnosis of venous thromboembolism by 25% over CTPA alone. This pictorial essay will review the normal venous anatomy, CTV technique, and the findings of acute and chronic DVT. Interpretive pitfalls and alternative diagnoses are also reviewed.     

In the era of multislice CT, do we still need leg ultrasonography to diagnose pulmonary embolism?

The results of a multicenter, randomized, prospective, noninferiority trial by Righini et al., together with the low prevalence of a positive CT venography (CTV) scan alone shown by many other investigators, indicate that leg studies after multislice CT angiography for thromboembolism are redundant. The proportion of diagnoses that are made on the basis of a positive CTV scan in patients with a negative multislice CT angiography scan, however, is 14% on average. The diagnostic yield of CTV and of compression ultrasound could be increased by their select use in patients who are likely to have deep-vein thrombosis. Radiation exposure from CTV can be reduced by eliminating imaging of the pelvic veins and by obtaining discontinuous axial images of the proximal leg veins. There are several valid reasons for recommending or not recommending leg studies in patients with suspected pulmonary embolism, and the choice of diagnostic tests should be individualized on a patient-by-patient basis.     

Bilateral pleural effusion and pulmonary edema caused by a fistulous aneurysm of the ductus arteriosus

We report an unusual case of pulmonary edema and rapid collection of bilateral pleural effusion caused by a fistulous large aneurysm of the ductus arteriosus (DAA). The diagnosis was performed by contrast CT and aortography. The cause of pulmonary edema and effusion was thought to be both elevated capillary pressure due to overload of the pulmonary circulation and decreased water clearance due to compression of the lymphatic system by the large DAA itself. Therefore, fistulous DAA should be considered when a continuous heart murmur and swelling in the aortic window are recognized. Once DAA is diagnosed, surgery should be performed without delay.     

Thromboembolism and Toxic Shock Syndrome: A Case Presentation and Literature Update

A case of progressive shock and multisystem organ failure is reported for an 18 year old Lebanese woman, clinically diagnosed as toxic shock syndrome (TSS). The patient developed cough and dyspnea during hospitalization; chest CT angiography revealed thromboembolism of the pulmonary artery. CBC analysis showed leukocytosis with a white cell count (WCC) with a marked increase in PT and PTT coupled with reduced protein S, antithrombin III, and protein C levels. The patient improved gradually and was discharged from the hospital 7 days later on oral anticoagulation, and was followed up for six months with no disease recurrence or complications. To our knowledge, this is the first reported case in the literature of toxic shock syndrome associated with pulmonary thromboembolism.     

Pulmonary thromboembolism during the Niigata Chuetsu earthquake in 2004]

We encountered 2 cases of pulmonary thromboembolism developed during refuge for Niigata Chuetsu earthquake in 2004. Case 1 was a 76-year-old woman who moved to the back seat of a car for refuge since the earthquake struck on October 23rd, 2004. When she emerged from the car on the morning of October 25th, she felt sudden dyspnea and lost consciousness. On arrival at the hospital, she had low blood pressure and hypoxemia, hypocapnia, and metabolic acidosis. Based on her clinical history and her symptoms, pulmonary thromboembolism was suspected and heparinization was begun immediately. In our hospital, the chest CT angiography proved the diagnosis. She was transferred to a university hospital for further treatment. Case 2 was a 79-year-old woman. She spent only one night in a car. Fifteen days after the earthquake, chest tightness and dyspnea occurred. Although her symptoms were improved and disappeared, she came to our hospital. Chest CT images confirmed pulmonary thromboembolism, and treatment with heparin was begun. We think this pulmonary thromboembolism was related to the knee-bending position she had assumed in the car and decreased activity during refuge. This is a clinical condition which could happen during disasters in the future. We should recognize the likelihood of pulmonary thromboembolisms in the disasters in the future.     

Isolated ductus arteriosus aneurysm in the fetus and infant: a multi-institutional experience

OBJECTIVES: The purpose of this study was to describe the clinical characteristics and outcome and to elucidate the pathogenesis of ductus arteriosus aneurysm (DAA). BACKGROUND: Ductus arteriosus aneurysm is a rare lesion that can be associated with severe complications including thromboembolism, rupture and death. METHOD: We reviewed the clinical records, diagnostic imaging studies and available histology of 24 cases of DAA, diagnosed postnatally (PD) in 15 and antenatally (AD) in 9 encountered in five institutions. RESULTS: Of PD cases, 13 presented at <2 months, and all AD cases were detected incidentally after 33 weeks of gestation during a late trimester fetal ultrasound study. Of the 24, only 4 had DAA-related symptoms and 6 had associated syndromes: Marfan, Smith-Lemli-Opitz, trisomies 21 and 13 and one possible Ehlers-Danlos. Three had complications related to the DAA: thrombus extension into the pulmonary artery, spontaneous rupture, and asymptomatic cerebral infarction. Six underwent uncomplicated DAA resection for ductal patency, DAA size or extension of thrombus. In the four examined, there was histologic evidence of reduced intimal cushions in two and abnormal elastin expression in two. Five of the 24 died, with only one death due to DAA. Of 19 survivors, all but one remain clinically asymptomatic at a median follow-up of 35 months; however, two have developed other cardiac lesions that suggest Marfan syndrome. A review of 200 consecutive third trimester fetal ultrasounds suggests an incidence of DAA of 1.5%. CONCLUSIONS: Ductus arteriosus aneurysm likely develops in the third trimester perhaps due to abnormal intimal cushion formation or elastin expression. Although it can be associated with syndromes and severe complications, many affected infants have a benign course. Given the potential for development of other cardiac lesions associated with connective tissue disease, follow-up is warranted.     

急性肺血栓栓塞症患者溶栓前后影像改变特点的研究

目的探讨急性肺血栓栓塞症患者溶栓前后影像学改变的特征。方法对29例急性肺血栓栓塞症患者溶栓前和溶栓后第3天、1周及第2周进行肺部CT平扫和CT肺动脉造影（CTPA）,溶栓前后影像改变对比分析。结果溶栓后第3天、1周及第2周肺不张楔形致密影的复张率分别为16.0%、12.0%、4.0%,病灶肺动脉充盈缺损存在率为13.8%、6.9%、3.5%,病灶局限性血管纹理稀疏存在率为31.0%、6.9%、3.5%,胸腔积液存在率73.7%、52.6%、42.1%,局部胸腔增厚存在率63.6%、59.1%、40.9%。结论溶栓能够大部分消除异常影像征象,但短期内依然存在不同程度的异常影像征,肺异常影像消除率最高是肺不张和局限性血管纹理,消除率最低是局部胸腔增厚,动态观察异常影像时决策治疗有重要临床意义。     

Three-dimensional helical computed tomographic angiography in neonates and infants with complex congenital heart disease

BACKGROUND: For the clinical management of patients with complex congenital heart disease (CHD), accurate evaluation of their morphologic conditions is critical. Three-dimensional (3D) helical computed tomography (CT) angiography has been used to assess the vascular system in adult patients; the indication for complex CHD, especially in the neonatal period, has not yet been defined. Therefore the purposes of our study were to determine the quality and limitations of current 3D helical CT angiography for neonates and infants with complex CHD and to assess the clinical utility of this technique. METHODS AND RESULTS: 3D helical CT angiography was performed in 17 patients with various types of complex CHD. Their median age was 41 days (range 3 days to 9 months), and mean body weight was 3.6 kg (range 2.2 to 8.5 kg). All 3D images were produced with the 3D reconstruction algorithm of shaded-surface display. Oral sedation was required in only 4 infants during the procedure. 3D helical CT angiography clearly demonstrated the shape and spatial relation of great arteries, proximal branch pulmonary arteries, anomalous pulmonary venous connections, the patent ductus arteriosus, and a shunt. The 3D information of extracardiac morphologic characteristics and 3D anatomic relation of each extracardiac structure were easily recognized by this imaging process. However, intracardiac structure could not be visualized because of blurred and/or unclear edges of the ventricular wall caused by respiratory movement. CONCLUSIONS: 3D helical CT angiography represents an important additional diagnostic tool and may become an alternative method to angiography or other noninvasive techniques used in the evaluation of extracardiac anomalies in neonates and infants with complex CHD.     

The use of D-dimers in the diagnosis of occult pulmonary emboli in HIV pulmonary disease--two case reports

Pulmonary thromboembolism is not considered a common cause of morbidity in HIV disease. Although anti-phospholipid antibodies are often seen in HIV disease, they are not associated with an increased thrombotic risk. Computed tomographic (CT) pulmonary angiography has been described as the imaging modality of first choice, as abnormal baseline chest X-rays may reduce the diagnostic utility of ventilation perfusion (VIQ) scanning. In HIV-negative individuals D-dimer testing has been shown to be a good screening tool in suspected pulmonary embolism. We present 2 cases where the diagnosis of pulmonary embolus was established using tests for the clotting degradation products D-dimers.     

Diagnosis of venous thromboembolism by single-detector row and multi-detector row CT angiography

Aim of this study is to determine the diagnostic value of pulmonary angiography performed by either single-detector row CT (SDCT) or multi-detector row CT (MDCT) in patients suspected of venous thromboembolism (VTE). SDCT was performed on 36 and MDCT on 18 of total of 54 patients on whom V/Q scintigraphy was obtained with a suspicion of VTE. Sixteen out of 54 cases got additional pulmonary DSA. Statistical analyses were based on final clinical diagnoses of the individual cases. Twenty-six out of 54 cases in the study got the final diagnoses of VTE and VTE was certainly excluded in the remaining 28. Sixteen out of true 26 VTE cases were in the SDCT group while the other 10 cases took place in the MDCT group, none of which was missed by either technique. There was one false positive result in the SDCT group and none in the MDCT group (96% and 100% specificity respectively, 100% sensitivity for both). Only 9% of all pulmonary emboli detected by SDCT assisted pulmonary angiography were located in subsegmental arterial branches, whereas 24% of emboli detected by MDCT angiography were subsegmental. Both SDCT and MDCT angiography are reliable tests in the detection of VTE. MDCT assisted pulmonary angiography is superior than SDCT assisted pulmonary angiography in subsegmental VTE detection.     

Initial clinical experience of real-time three-dimensional echocardiography in neonates with isolated congenital ductus arteriosus aneurysm

BACKGROUND: Congenital ductus arteriosus aneurysm (DAA) was considered rare but potentially fatal abnormality, often followed by surgical intervention after careful evaluation. This prospective study used real-time three-dimensional echocardiography (RT3DE) to assist in evaluation of neonatal DAA. METHODS: A total of 1390 full-term neonates were enrolled in this study between 2002 and 2003. They received two-dimensional echocardiographic (2DE) screening and periodic follow-up. RT3DE was performed selectively for newborns with DAA. RESULTS: DAA were detected in 116 (8.34%) newborns using 2DE. Maximum diameter of the DAAs ranged from 6.8 to 14.0 mm (8.2+/-1.1 mm). None of the cases were symptomatic or had complications related to DAA. There were no significant differences in sex and gestational age between the newborns with and without DAA. Neonates with DAA had a higher birth body weight and a higher incidence of large-for-gestational-age (P<0.05). RT3DE provided instant, consistent and reliable 3D images of DAA and its related structures and allowed for more rapid examination times and reduction of baby wait times. CONCLUSIONS: Congenital DAA is as common as has been previously reported. RT3DE is useful in assisting evaluation of DAA. Preferred images of DAA were typically visualized in the high parasternal short-axis view before the third day of life. Routine use of RT3DE is suggested to enhance assessment of neonates with DAA detected by 2DE.     

急性肺血栓栓塞症57例临床特点分析

目的分析肺血栓栓塞症（PTE）的临床特点,提高其早期诊断率。方法回顾性分析57例PTE患者的临床特点。结果PTE患者临床表现缺乏特异性,常伴有深静脉血栓形成、创伤和（或）骨折、心血管疾病等危险因子;动脉血气分析、D-二聚体、心电图检查可提示PTE;超声心动图对PTE有诊断作用;螺旋CT肺动脉血管造影（CTPA）是确诊PTE较可靠的方法。结论PTE是常见的肺血管疾病,对有症状的高危患者应及早行CTPA检查,以明确诊断。     

新疆维族肺血栓栓塞症患者的PS-K196E多态性探讨

目的探讨蛋白S基因1(protein S1,PROS1)赖氨酸196谷氨酸的(PS-Lys196 Glu即PS-K196E,单字母命名法K-Lys,E-Glu)多态性与新疆地区维族人群肺血栓栓塞症(pulmonary thromboembolism,PTE)发生的相关性。方法采用病例—对照研究,病例组为经放射性肺通气/灌注显像和(或)螺旋CT肺动脉造影检查,并结合临床资料确诊的PTE患者100例,对照组为来自同一地区,性别、年龄匹配的健康对照100例。用酶联免疫吸附试验法测定PS活性(PS:A)。Massarray技术平台进行芯片点制及质谱检测PS-K196E的多态性。结果 PTE组和对照组的PS抗原活性分别是53.84%和90.50%,K196E突变杂合子携带者的PS活性降低到70.29%,纯合子携带者的PS活性降低到49.85%,差异具有统计学意义;病例组和对照组AG基因型的频率分别是55%和40%,对照组GG基因型的频率是35%和22%,差异有统计学意义(χ2=17.666,P0.05);AG和GG基因型与AA基因型的比值比分别是0.191和0.161(OR=0.191,95%CI 0.085～0.429;OR=0.165,95%CI 0.069～0.398);病例组和对照组的等位基因是G频率的62.5%和42%,差异有统计学意义(χ2=16.844,P0.05)。结论 PS-K196E突变的杂合子和纯合子的蛋白S的活性均降低,尤其是后者更明显,PS-K196E多态性与新疆地区维族人肺栓塞的发生可能有关。     

18F-fluorodeoxyglucose positron emission tomography as a noninvasive method for the diagnosis of primary pulmonary artery sarcoma

Pulmonary artery sarcomas are rare, difficult-to-diagnose tumors that frequently mimic chronic pulmonary thromboembolism. We report the cases of two female patients with clinical signs of dyspnea and lung masses associated with pulmonary artery filling defects on chest CT angiography. We performed 18F-fluorodeoxyglucose positron emission tomography, which revealed increased radiotracer uptake in those lesions. Pulmonary artery sarcoma was subsequently confirmed by anatomopathological examination. We emphasize the importance of this type of tomography as a noninvasive method for the diagnosis of these tumors.