Imaging after radiation therapy of thoracic tumors.

Radiation-induced lung disease (RILD) is frequent after therapeutic irradiation of thoracic malignancies. Many technique-, treatment-, tumor- and patient-related factors influence the degree of injury sustained by the lung after irradiation. Based on the time interval after the completion of the treatment RILD presents as early and late features characterized by inflammatory and fibrotic changes, respectively. They are usually confined to the radiation port. Though the typical pattern of RILD is easily recognized after conventional two-dimensional radiation therapy (RT), RILD may present with atypical patterns after more recent types of three- or four-dimensional RT treatment. Three atypical patterns are reported: the modified conventional, the mass-like and the scar-like patterns. Knowledge of the various features and patterns of RILD is important for correct diagnosis and appropriate treatment. RILD should be differentiated from recurrent tumoral disease, infection and radiation-induced tumors. Due to RILD, the follow-up after RT may be difficult as response evaluation criteria in solid tumours (RECIST) criteria may be unreliable to assess tumor control particularly after stereotactic ablation RT (SABR). Long-term follow-up should be based on clinical examination and morphological and/or functional investigations including CT, PET-CT, pulmonary functional tests, MRI and PET-MRI.

Diagnosis and treatment of pulmonary arteriovenous malformations in hereditary hemorrhagic telangiectasia: An overview.

Hereditary hemorrhagic telangiectasia (HHT) or Rendu-Osler-Weber disease is an autosomic dominant disorder, which is characterized by the development of multiple arteriovenous malformations in either the skin, mucous membranes, and/or visceral organs. Pulmonary arteriovenous malformations (PAVMs) may either rupture, and lead to life-threatening hemoptysis/hemothorax or be responsible for a right-to-left shunting leading to paradoxical embolism, causing stroke or cerebral abscess. PAVMs patients should systematically be screened as the spontaneous complication rate is high, by reaching almost 50%. Neurological complications rate is considerably higher in patients presenting with diffuse pulmonary involvement. PAVM diagnosis is mainly based upon transthoracic contrast echocardiography and CT scanner examination. The latter also allows the planification of treatments to adopt, which consists of percutaneous embolization, having replaced surgery in most of the cases. The anchor technique consists of percutaneous coil embolization of the afferent pulmonary arteries of the PAVM, by firstly placing a coil into a small afferent arterial branch closely upstream the PAVM. Enhanced contrast CT scanner is the key follow-up examination that depicts the PAVM enlargement, indicating the various mechanisms of PAVM reperfusion. When performed by experienced operators as the prime treatment, percutaneous embolization of PAVMs, is a safe, efficient and sustained therapy in the great majority of HHT patients.

Radio-anatomy of the superior vena cava syndrome and therapeutic orientations.

Superior vena cava syndrome (SVCS) groups all the signs secondary to the obstruction of superior vena cava drainage and the increase in the venous pressure in the territories upstream. There are two major causes of SVCS: malignant, dominated by bronchopulmonary cancer, and benign, often secondary to the presence of poorly positioned implantable venous devices. CT scan is the key examination for the exploration of SVCS. It specifies the characteristics of the stenosis, its aetiology and detects collateral venous routes. Scannography reconstructions provide a true map of the obstacle, indispensable in planning the endovascular treatment.

Liver metastasis of a mucinous colonic carcinoma mimicking a haemangioma in T2-weighted sequences.

We report the case of a patient with a single liver metastasis of a mucinous colonic carcinoma that mimics a haemangioma in T2-weighted sequences. Although a very high T2 signal in non-cystic lesions is highly specific for the diagnostic of haemangioma, the use of gadolinium-enhancement MRI is recommended. In patients with a history of neoplasia, the diagnosis of benign liver nodules should be made with caution.

[Embolization of localized pulmonary arteriovenous malformations in adults]. / Embolisation des malformations artérioveineuses pulmonaires localisées de l'adulte.

OBJECTIVES: To report our experience using embolization in managing localized pulmonary arteriovenous malformations in adults. MATERIAL: and methods. All patients presenting with localized pulmonary arteriovenous malformations treated with embolization were included in the study. Clinical presentation (respiratory symptoms and previous history of paradoxical embolism) and the characteristics of pulmonary arteriovenous malformations (single or multiple, location, diameter of the afferent artery and simple or complex angioarchitecture) before embolization were analyzed. The details of the procedure, including the number of pulmonary arteriovenous malformations embolized, the number of coils used, and the type of intraoperative complications were recorded. Postembolization clinical and imaging follow-up were described. RESULTS: Forty-two patients (26 women, 16 men; mean age, 45 years), including 36 with hereditary hemorrhagic telangiectasia were treated with embolization. Twenty-two patients (53%) were dyspneic and 12 (29%) had a previous history of paradoxical embolism prior to embolization. Forty-seven procedures were carried out on a total of 99 pulmonary arteriovenous malformations (mean, 2.3 per patient), using 530 coils (12.6 per patient). The pulmonary arteriovenous malformations were located in the lower lobes in 60% of cases and a simple architecture was reported in 81% of cases. The average diameter of the afferent artery was 6mm. No preoperative complications were reported. After embolization, two patients (5%) presented with a paradoxical embolism and five patients out of 22 (23%) remained dyspneic. The rate of complete occlusion of treated arteriovenous malformations was 92% using computer tomography. CONCLUSION: Embolization is a highly effective and safe technique for treating pulmonary arteriovenous malformations. Improvement in dyspnea and prevention of paradoxical embolism can be expected. A high technical success rate can be obtained by experienced interventional radiologists.

[Negative D-dimers and peripheral pulmonary embolism]. / D-dimères négatifs et embolies pulmonaires périphériques.

The measurement of D-dimers is a recent addition to the diagnostic strategy of pulmonary embolism and has been shown to be a valuable tool with excellent sensitivity. However, there have been rare reports of patients with pulmonary embolism but negative D-dimer tests. The object of this study was to study patients with pulmonary embolism but negative D-dimers and to compare them with a population of patients with pulmonary embolism and raised D-dimers. One hundred and fifty consecutive patients admitted for pulmonary embolism were included in this study. All underwent measurement of D-dimers (normal <500 ng/ml) by an ELISA technique. The data of clinical examination and complementary investigations were analysed with respect to the D-dimers result. The sensitivity of raised D-dimers for pulmonary embolism was 96% (6 patients had results <500 ng/ml). The finding of chest pain was statistically greater in the group with negative D-dimers (p=0.01). In these cases, the emboli were all distal (p=0.0003), the average Miller index was significantly lower than in patients with high D-dimers (p=0.04) and the diagnostic value of ultrasound investigations (echocardiography, ultrasonography of lower limb veins) was less (p<0.0001). The authors conclude that measurement of D-dimers by the ELISA method may be non-diagnostic in distal pulmonary embolism and one explanation could be the less extensive thromboembolic process. In cases with negative D-dimers, a strong clinical suspicion of pulmonary embolism should lead to the request for further investigations.

CT features of a voluminous gastric trichobezoar.

We report on the case of a 15-year-old girl with a voluminous gastric trichobezoar imaged by CT. The absence of any attachment of the mass to the gastric wall and the presence of air within the mass are very suggestive for diagnosis.

New CT index to quantify arterial obstruction in pulmonary embolism: comparison with angiographic index and echocardiography.

OBJECTIVE: This study was designed to define and evaluate a specific index to quantify arterial obstruction with helical CT in acute pulmonary embolism. MATERIALS AND METHODS: Fifty-four patients (mean age, 56 years) with proven pulmonary emboli among 158 consecutive patients, who had undergone both CT and pulmonary angiography for clinically suspected pulmonary embolism, were eligible for the study. The CT obstruction index was defined as (n. d) (n, value of the proximal clot site, equal to the number of segmental branches arising distally; d, degree of obstruction scored as partial obstruction [value of 1] or total obstruction [value of 2]). We compared the CT obstruction index with pulmonary arterial obstruction on angiography (assessed by the Miller index), using linear regression, and correlated it with findings on echocardiography. Interobserver variability was determined for both CT and pulmonary angiography indexes. RESULTS: The CT obstruction index (29% +/- 17%) and the Miller index (43% +/- 25%) were well correlated (r = 0.867, p < 0.0001) with an excellent concordance between investigators for both the CT index (r = 0.944, p < 0.0001) and the Miller index (r = 0.904, p < 0.0001). A CT obstruction index greater than 40% identified more than 90% of patients with right ventricular dilatation. CONCLUSION: The degree of arterial obstruction in pulmonary embolism may be quantified by a specific CT index that appears reproducible and highly correlated to the previously described index with pulmonary angiography. Further evaluations are needed to investigate the usefulness of the CT obstruction index for stratification of patient risk and determining therapeutic options.

[Intralobar sequestration of the lung in an adult (type 1 of pryce). Treatment by coil embolization]. / Séquestration pulmonaire intralobaire de type pryce 1 chez l'adulte. Vaso-occlusion par spires métalliques.

A 34 year old patient presented with recurrent hemoptysis. A chest radiograph was normal. Helical CT angiogram of the chest with tridimensional reconstructions demonstrated an intralobar pulmonary vascular sequestration Pryce I-type of the right lower lobe. The angiography confirmed the diagnosis showing a large feeding artery arising from the coeliac trunk. An embolization of the feeding artery using metallic coils was performed. Transient pulmonary infarction occurred immediately after treatment. At two years follow-up, the patient remains asymptomatic. Percutaneous embolization of this rare pulmonary vascular malformation is an alternative to surgical treatment.

Dual-slice helical CT of the thoracic aorta.

With the advent of helical CT, the capability of noninvasive imaging of the thoracic aorta has been enhanced considerably. In this article, we describe the potential of helical CT using dual-slice technology to evaluate thoracic aortic diseases such dissection, aneurysm, trauma, infection, inflammation, thromboembolic disease, and postoperative complications. Technical considerations for optimal CT imaging as well as limitations of helical CT are highlighted.

Diagnosis of saphenous coronary graft aneurysm by spiral computed tomography.

We report two cases of coronary saphenous vein graft aneurysms diagnosed by spiral computed tomography.