Video fluoroscopy for pulmonary artery catheter insertion in high-risk situation of knotting or misplacement

Pulmonary artery catheter (PAC) insertion in patients with severe pulmonary hypertension, right heart dilation and failure, is very challenging. Misplacement and knotting are rare but could be serious complications leading to a delay of the monitoring and sometimes an emergent not expected intervention. Here we report a case of a patient admitted to Intensive Care Unit (ICU) with an acute hypoxemic respiratory failure. She had a history of chronic respiratory failure with pulmonary hypertension and right heart failure. We decided to monitor her cardiac output and pulmonary pressure with a PAC. Repeated attempts to reach the pulmonary artery (PA) were unsuccessful and the PAC was knotted and blocked at the distal tip of the introducer. Under fluoroscopy the knot was released by radiologist. Few days later, a monitoring of PA pressure was needed to guide a PA vasodilator treatment. Under fluoroscopic guidance with the supervision of radiologist, the catheter was successfully placed in the PA at the first attempt. Despite some limitations (patient displacement and radiation), this technique is more accurate than waveform guidance. We suggest in specific situations (low cardiac output, severe pulmonary hypertension, and severe tricuspid regurgitation) to consider first fluoroscopy.

Catheter-directed thrombolysis in COVID-19 pneumonia with acute PE: Thinking beyond the guidelines

•Patients having COVID-19 pneumonia are at risk of venous thromboembolism. •Prophylaxis versus anticoagulation for severely ill patients is currently debated. •No specific guidelines for the management of severe pulmonary embolism exist. •Endovascular pulmonary embolism therapy may play a critical role in severe COVID-19.

Pulmonary embolism in patients with COVID-19: Time to change the paradigm of computed tomography

OBJECTIVE

To raise awareness for possible benefits of examining known COVID-19 patients presenting sudden clinical worsening with CT pulmonary angiography instead of standard non-contrast chest CT.

[Cardiac imaging: specific clinical role of newly developed non invasive techniques. Part II: functional evaluation]

The non-invasive evaluation of myocardial ischemia is a priority in cardiology. The preferred initial non-invasive test is exercise ECG, because of its high accessibility and its low cost. Stress radionuclide myocardial perfusion imaging or stress echocardiography are now routinely performed, and new non-invasive techniques such as perfusion-MRI, dobutamine stress-MRI or 82rubidium perfusion PET have recently gained acceptance in clinical practice. In the same time, an increasing attention has been accorded to the concept of myocardial viability in the decisional processes in case of ischemic heart failure. In this indication, MRI with late enhancement after intravenous injection of gadolinium and 18F-FDG PET showed an excellent diagnostic accuracy. This article will present these new imaging modalities and their accepted indications.

[Non invasive cardiac imaging: clinical role of newly developed modalities. Part III: non ischemic cardiac diseases]

Echocardiography is the preferred initial noninvasive test to assess heart muscle and heart valves. Cardiac MRI has a unique capacity to directly characterise myocardial tissue with specific imaging sequences and late enhancement pattern after gadolinium injection, and has a specific role in the diagnosis of cardiomyopathies. In valvular heart diseases, cardiac MRI precisely measures the severity of aortic or pulmonary regurgitation. In pericardial heart diseases, and specifically when constrictive pericarditis is suspected, cardiac MRI and/or CT are useful to look for pericardial thickening. Cardiac CT and MRI are very rapidly developing techniques in cardiology; the use of these expensive techniques must follow the currently accepted indications in order to be integrated in a rational diagnosis process in clinical practice.

[Hybrid treatment of aortic aneurysms]

The hybrid treatment of aortic aneurysms is indicated in patients having the ostia of supra aortic or visceral branches taken in to the aneurysm. Indeed, these lesions are not eligible for classic endovascular treatment because the existing endoprostheses cannot provide perfusion of the side branches without inducing major endoleaks. The surgical technique consists of 2 steps: firstly, a by-pass between normal aorta and the major aortic branches involved in the aneurysm is performed to guarantee the perfusion of the organs such as brain, bowel, and after endoprosthesis deployment. Secondly, the endoprosthesis is deployed using the classical technique to isolate the aneurysm. The hybrid approach provides safe and reliable treatment of complex aortic aneurysms with mortality and morbidity rate far below the classical open surgery.

Assessment of occlusive arterial disease of abdominal aorta and lower extremities arteries: value of multidetector CT angiography using an adaptive acquisition method

We evaluated 16-detector-row CT in the assessment of occlusive peripheral arterial disease (PAD) of the abdominal aorta and lower extremities using an adaptive method of acquisition to optimise arterial enhancement especially for the distal foot arteries. Thirty-four patients underwent transcatheter angiography (TCA) and CT angiography within 15 days. For each patient, table speed and rotation were selected according to the calculated optimal transit time of contrast material obtained after a single bolus test and two dynamic acquisitions at aorta and popliteal arteries. Analysis included image quality and detection of stenosis equal or greater than 50% on a patient basis and on an arterial segment basis. Sensitivity and specificity of CT were calculated with the TCA considered as the standard of reference. CT was conclusive in all segments with no technical failures even in difficult cases with occluded bypasses and aneurysms. On patient-basis analysis, the overall sensitivity and specificity to detect significant stenosis greater than 50% were both 100%. Segmental analysis shows high values of sensitivity and specificity ranging from 91 to 100% and from 81 to 100%, respectively, including distal pedal arteries. Sixteen-detector-row CT angiography using an adaptive acquisition improves the image quality and provides a reliable non-invasive technique to assess occlusive peripheral arterial disease, including distal foot arteries.

An accurate and reproducible scheme for quantification of coronary artery calcification in CT scans

The coronary artery disease is a major cause of deaths in the western world. One indicator for coronary artery disease (CAD) is coronary artery calcification (CAC). An accurate and reproducible scheme is desired to monitor the progression of patient's coronary calcification in follow-up studies. Traditional approaches for CAC estimation lack to provide accurate and reproducible results. In This work, a new adaptive and stochastic 3D method has been proposed by employing a modified expectation-maximisation (MEM) algorithm. It is less sensitive to partial volume effects, motion effects, slice thickness and low dose. Accuracy of the proposed method was measured by a cardiac CT stationary phantom containing 6 calcium inserts of predetermined size and density that were scanned 90 times using 15 different protocols based on slice thickness and radiation. Reproducibility was measured in 35 patients who were each scanned twice with the patient being repositioned before the second scan. Compared with the Agatston based method, it is shown that the proposed algorithm gives better results in terms of accuracy and reproducibility.

[CT-angiography of peripheral arterial diseases: principle and current indications]

Recent advances in multi-detector CT technology, improving the spatial resolution and the acquisition time, provide basis for CT-angiography of the abdominal aorta and peripheral vessels of the lower extremities. The objective of this review is to help the clinician to understand principle of CT-angiography of peripheral vessels and to provide an overview of the current clinical applications as well as the futures directions in diagnosis, treatment planning and post-therapeutic surveillance in peripheral vascular diseases.

[Management of critical limb ischemia]

Critical limb ischemia (CLI) is the leading cause of major leg amputation. Diabetes, smoking and end stage renal disease are the main risk factors for CLI. Despite their reduced survival rate, most CLI patients should be treated by surgical or endovascular arterial reconstruction, since amputation rate with conservative treatment alone is as high as 95% at 1 year in surviving patients with tissue loss, and can be reduced to 25% with successful reconstruction. When arterial reconstruction is impossible or fails, spinal cord stimulation also allows to avoid major amputation in up to 75% of precisely selected patients. Timely management and multidisciplinary approach are advised to reduce the risk of major amputation.

[Non invasive multidetector CT angiography of coronary arteries: when and how should I do?]

Recent advances in multi-detector computed tomography technology offer a reliable tool for coronary arteries visualization and atherosclerotic plaque assessment. The objective of this article is to describe the principle of coronary angiography using multi-detector computed tomography, review the current diagnostic performances and help the reader to understand current applications and future challenges of multi-detector computed tomography in coronary artery disease diagnosis and management.

[Radiofrequency tumor ablation: from the liver to the lung passing by the kidney]

Tumor ablation using radiofrequency technique is an interventional radiology method for the treatment of liver renal or pulmonary tumors. The size of the lesion is the limiting factor of this technique. Tumors below 3 cm are treated with a 90% efficacy in one session. Complications are variable according to the organ treated.

[Incidence of acute cor pulmonale and deep venous thrombosis in acute pulmonary embolism]

OBJECTIVE

Ultrasounds are a useful tool when looking for indirect evidence in favor of pulmonary embolism. The aim of this study was to determine the incidence of acute cor pulmonale and deep venous thrombosis revealed by ultrasonographic techniques in a population of patients presenting with pulmonary embolism.

METHODS

96 consecutive patients with a mean (+/- SD) age of 65 +/- 15 years, admitted to our hospital for pulmonary embolism were included in this study. The diagnosis of pulmonary embolism was made either by spiral computed tomography or selective pulmonary angiography. Each patient subsequently underwent both trans-thoracic echocardiography and venous ultrasonography. The diagnostic criterion used for defining acute cor pulmonale by echocardiography was the right to left ventricular end-diastolic area ratio over (or equal to) 0.6. Diagnosis of deep venous thrombosis was supported by the visualization of thrombi or vein incompressibility and/or the absence of venous flow or loss of flow variability by venous ultrasonography.

RESULTS

Using ultrasounds, an acute cor pulmonale was found in 63% of our patients while 79% were found to have deep venous thrombosis and 92% of the patients had either acute cor pulmonale or deep venous thrombosis or both. All of the patients with proximal pulmonary embolism had acute cor pulmonale and/or deep venous thrombosis. The presence of acute cor pulmonale on echocardiography was significantly higher in patients with proximal pulmonary embolism (p < 0.0001).

CONCLUSION

This study emphasizes the potential value of ultrasonographic techniques in the diagnosis of acute pulmonary embolism.

Detection of renal artery stenosis: prospective comparison of captopril-enhanced Doppler sonography, captopril-enhanced scintigraphy, and MR angiography

OBJECTIVE

The objective of our study was to compare the value of captopril-enhanced Doppler sonography, captopril-enhanced renal scintigraphy, and gadolinium-enhanced MR angiography for detecting renal artery stenosis.

SUBJECTS AND METHODS

Forty-one patients with suspected renovascular hypertension were prospectively examined with captopril-enhanced Doppler sonography, captopril-enhanced renal scintigraphy, gadolinium-enhanced MR angiography, and catheter angiography. The sensitivity and specificity of each technique for detecting renal artery stenosis measuring 50% or greater and 70% or greater were compared using the McNemar test. Positive and negative predictive values were estimated for populations with 5% and 30% prevalence of renal artery stenosis. Kappa values for interobserver agreement were assessed for both gadolinium-enhanced MR angiography and catheter angiography.

RESULTS

For detecting renal artery stenosis measuring 50% or greater, the sensitivity of gadolinium-enhanced MR angiography (96.6%) was greater than that of captopril-enhanced Doppler sonography (69%, p = 0.005) and captopril-enhanced renal scintigraphy (41.4%, p = 0.001). No significant difference in specificity was observed among modalities. For renal artery stenosis measuring 50% or greater, positive and negative predictive values were respectively 62% and 86% for captopril-enhanced Doppler sonography, 49% and 76% for captopril-enhanced renal scintigraphy, and 53% and 98% for gadolinium-enhanced MR angiography. Interobserver agreement was high for both gadolinium-enhanced MR angiography (kappa = 0.829) and catheter angiography (kappa = 0.729).

CONCLUSION

Gadolinium-enhanced MR angiography is the most accurate noninvasive modality for detecting renal artery stenosis greater than or equal to 50%. The use of captopril-enhanced Doppler sonography in combination with gadolinium-enhanced MR angiography for identifying renal artery stenosis needs to be evaluated with a cost-effectiveness analysis.

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.

A new vascular sealant (Sealgel) to achieve rapid hemostasis after percutaneous angioplasty in anticoagulated patients: clinical feasibility and preliminary results

The aim of this study was to assess the feasibility of a new vascular sealant (Sealgel) to provide rapid hemostasis in anticoagulated patients after percutaneous transluminal angioplasty (PTA). Sealgel was designed with ancrod (10 mg) and tranexamic acid (80 mg) dissolved in a hyaluronic acid gel (3 ml). Fifty anticoagulated patients (heparin, aspirin, ticlopidin) who underwent PTA of coronary artery were enrolled in the study. Sealgel (3 ml) was delivered under manual compression through a 9-F cannula at the arterial puncture site after the introducer sheath removal at the end of PTA procedure. Hemostasis time as well as complications were recorded. Sealgel was successfully delivered in 98 % of patients. Hemostasis occurred within 15 mn of manual compression in 82 % of patients, within 25 mn in 98 %, and failed in 1 patient (2 %). Hematoma (6-cm diameter) was observed in 1 patient and late bleeding in another one. There were no clinical signs of embolism, inflammatory swelling, local infection, vascular fistula, or pseudoaneurysm. No surgery or blood transfusion was required. Sealgel application after PTA in anticoagulated patient is feasible and secure. Preliminary results suggest that the Sealgel brought about rapid hemostasis; however further studies are needed to determine its clinical efficacy.

Volumetric quantification of coronary artery calcifications using dual-slice spiral CT scanner: improved reproducibility of measurements with 180 degrees linear interpolation algorithm

PURPOSE

The purpose of this work was to determine the reproducibility of coronary total calcium score (TCS) with dual-slice helical CT and compare three acquisition protocols.

METHOD

Fifty patients (59 +/- 10 years old) underwent dual-slice helical CT (collimation = 2 x 2.5 mm) and coronary angiography. Two successive scans were performed, resulting in three sets of images: pitch = 1, 360 degrees linear interpolation (LI) (A360); pitch = 1, 180 degrees LI (A180); and pitch = 1.5, 180 degrees LI (B180). TCS values, calculated using a volumetric method with a threshold of 90 HU, were compared, and the interscan variation was determined. Diagnostic performances were compared with receiver operating characteristic curves.

RESULTS

Protocol A360 provided significantly lower TCS than protocols A180 and B180 (p < 0.0001). No statistical difference was seen between A180 and B180, which provided the lowest interscan variation (40 +/- 58%). However, no significant clinical impact of the observed interscan variations was found.

CONCLUSION

Reproducibility of TCS with dual-slice helical CT is improved by the 180 LI algorithm. However, dual-slice helical CT is not sufficiently reproducible to allow serial quantification of TCS over time.

Implanted central venous catheter-related acute superior vena cava syndrome: management by metallic stent and endovascular repositioning of the catheter tip

We describe a case of a 49-year-old woman with stage-IIIB lung adenocarcinoma who experienced an acute superior vena cava syndrome related to an implanted central venous catheter without associated venous thrombosis. The catheter was surgically implanted for chemotherapy. Superior vena cava syndrome appeared after the procedure and was due to insertion of the catheter through a subclinical stenosis of the superior vena cava. Complete resolution of the patient's symptoms was obtained using stent placement and endovascular repositioning of the catheter tip.

[Coronary steal syndrome by systemic pulmonary hypervascularization fed by a mammary-left anterior descending artery bypass. Treatment by embolization]

We report a case of coronary-steal syndrome which occurred after coronary bypass surgery. It was related to systemic hypervascularization of the lung caused by a bronchopathy. The steal syndrome was fed by an ectopic bronchial artery arising from the internal mammary--left anterior descending artery bypass graft. The myocardial ischemia disappeared after hyperselective embolization of the ectopic bronchial artery. The authors outline the rarity of this syndrome and its pathophysiology. They insist on the necessity to perform broncho-systemic arteriography for candidates to coronary surgery, in patients with thoracic diseases which can induce systemic hypervascularization of the lung.

Pulmonary embolism detection: prospective evaluation of dual-section helical CT versus selective pulmonary arteriography in 157 patients

PURPOSE

To evaluate the accuracy of dual-section helical computed tomography (CT) in acute pulmonary embolism (PE) diagnosis.

MATERIALS AND METHODS

Of 204 consecutive patients with clinically suspected acute PE (mean age, 58 years +/- 14 [SD]), 158 were enrolled. All patients underwent dual-section helical CT (2.7-mm effective section thickness) and selective pulmonary arteriography within 12 hours of each other. Each image was analyzed independently by two observers, who determined image quality and presence of PE among arterial segments, including at the subsegmental level. The final diagnosis was made with consensus.

RESULTS

Selective pulmonary arteriography was considered optimal in 147 (93%), suboptimal in 10 (6%), and inconclusive in one (0.6%) of 158 patients. Dual-section helical CT findings were considered technically optimal in 140 (89%), suboptimal in 11 (7%), and inconclusive in six (4%). Selective pulmonary arteriography demonstrated PE in 62 patients. Four (6%) of 62 patients had isolated subsegmental PE. The sensitivity of dual-section helical CT was 90%, and the specificity was 94%. The positive and negative predictive values were 90% and 94%, respectively.

CONCLUSION

Dual-section helical CT is an improvement in helical CT that offers a high sensitivity and specificity for the depiction of PE, including at the subsegmental level. Dual-section helical CT can replace pulmonary arteriography for the direct demonstration of PE in a majority of patients.

[Imaging features of gastric stromal tumors: radiologic-pathologic correlation. Report of 4 cases]

GOAL

This study concerns the new anatomo-pathologic semantics of the ancient gastric leiomyoblastoma that become gastric stromal tumors (GST) and identified as stemming of "pace-maker" cells of Cajal related to the immunohistochemical characterization of the phenotype.

MATERIAL

and methods. We limited the study to the mesenchymatous tumors to "pacemaker" cells. For this purpose, we report four documented observations of gastric stromal tumors correlated to the histology and to the immunohistochemical study.

RESULTS

Although some signs are often described (exogastric development, heterogeneity with cystic and necrotic component, predominating peripheral enhancement...), radiological aspects of these tumors are not specific because, analogues to the other mesenchymal tumors (leiomyoma or schwannoma). The topographic diagnosis is difficult, realized by echoendoscopy, CT scan and MRI. The irregularity of contours evokes the malignancy as hemoperitoneum. GST do not show lymphophilic behavior that differentiates them from the adenocarcinomas and gastric lymphomas. The surgical treatment is the best treatment, allowing the immuno-histological diagnosis of certainty from the complete operative specimen.

CONCLUSION

Some tumors are difficult in classifying despite classic histology necessitating immunohistochemical tests for the identification of muscular, nervous, autonomous nervous system flexion of mesenchymatous tumors with epithelioid or spindle cells of the gastrointestinal tract. Then a radio-clinical follow-up is therefore indicated: the evolution is the alone real marker of malignancy.

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.

[Leiomyosarcoma of the superior vena cava: diagnosis by endovascular biopsy]

We report the case of a 69-year-old woman with leiomyosarcoma of the superior vena cava presenting with acute superior vena cava syndrome (SVCS). CT and MRI failed to fully characterize the endovascular process. Percutaneous endovascular biopsy, followed by metallic stent placement to treat the SVCS, confirmed the diagnosis. Symptoms resolved within 48 hours and surgical resection of the tumor was performed one month later. Unfortunately the patient died two weeks later because of intracranial hemorrhage.

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.

Unusual radiologic findings in the thorax after radiation therapy

Radiation therapy is used to treat many intrathoracic and chest wall malignancies. A variety of changes may occur after radiation therapy to the thorax. Radiation therapy produces dramatic effects in the lung. Pulmonary necrosis is an uncommon, severe, late complication of adjuvant postoperative radiation therapy. Bronchiolitis obliterans with organizing pneumonia is a distinct clinicopathologic entity characterized by patchy, migratory, peripheral air-space infiltrates. Radiation therapy can also cause spontaneous pneumothorax, mesothelioma, and lung cancer. In the mediastinum, radiation therapy may cause thymic cysts, calcified lymph nodes, and esophageal injuries. Cardiovascular complications of radiation therapy are often delayed and insidious. Premature coronary artery stenosis occurs after radiation therapy to the mediastinum. Radiation therapy may also give rise to calcifications of the ascending aorta, pericardial disease, valvular injuries, and conduction abnormalities. Women who undergo thoracic irradiation before the age of 30 years have a high risk of developing a second breast cancer. Radiation-induced sarcomas are an infrequent but well-recognized complication of radiation therapy. Other chest wall injuries due to radiation therapy are osteochondroma and rib or clavicle fractures. Knowledge of the imaging features of injuries caused by radiation therapy can prevent misinterpretation as recurrent tumor and may facilitate further treatment.

Can knitting structure affect dilation of polyester bifurcated prostheses? A randomized study with the use of helical computed tomography scanning

PURPOSE

The aim of this study was to prospectively evaluate the postoperative dilation of two types of knitted polyester arterial prostheses with the use of helical computed tomographic scanning.

METHODS

Thirty-four patients who underwent aortoiliac or aortofemoral bifurcation grafting were randomized to receive a collagen-sealed warp-knitted polyester graft (n = 16 patients) or a gelatin-sealed Köper-knitted polyester graft (n = 18 patients). Alterations in size of all parts of the grafts were evaluated by helical computed tomographic scanning at postoperative day 8, at 3 months, and at 6 months.

RESULTS

On postoperative day 8, the mean dilation of the Köper-knitted grafts was 18% +/- 8% for the stem and 15% +/- 12% for the limbs. At the same time period, the mean dilation of warp-knitted grafts was 27% +/- 13% for the stem and 33% +/- 18% for the limbs. No increase in graft dilation was observed at 3 and 6 months. Despite the wide range of values among patients with the same graft type, at each time interval, the Köper-knitted grafts dilated significantly less than the warp-knitted grafts (P <. 05).

CONCLUSION

In this randomized study, helical computed tomographic scanning was an accurate technique with which to assess graft dilation. For a 6-month follow-up interval, the Köper-knitted polyester structure dilated less than the warp-knitted structure. Longer-term serial scans should allow a better understanding of the clinical significance of graft dilation.

Abdominal aortic aneurysm: pretherapy assessment with dual-slice helical CT angiography

OBJECTIVE

The purpose of this study was to evaluate dual-slice helical CT in the pretherapy assessment of abdominal aortic aneurysms.

SUBJECTS AND METHODS

Dual-slice helical CT angiography was performed in 47 consecutive patients (mean age, 59 years) with abdominal aortic aneurysm to determine whether we could then evaluate the extent of aneurysm and see associated renal, celiac, mesenteric, and iliofemoral artery disease. Results were compared with those of digital subtraction angiography (n = 47) and surgery (n = 37).

RESULTS

The proximal and distal extents of abdominal aortic aneurysm correlated well with surgical findings. Dual-slice helical CT showed all main (n = 102) and accessory (n = 13) renal arteries with a sensitivity of 91% and a specificity of 100% for revealing associated renal artery stenosis exceeding 50%. Sensitivity and specificity of dual-slice helical CT for revealing stenosis exceeding 75% in celiac and superior mesenteric arteries were both 100%. Three of four iliofemoral artery stenoses and two occlusions of the common iliac artery were revealed by dual-slice helical CT.

CONCLUSION

Helical CT angiography with dual-slice scanning is a useful and minimally invasive technique that can provide with high accuracy all the necessary information for treatment of abdominal aortic aneurysm.

[Bronchial and pulmonary vaso-occlusions]

The technique of vaso-occlusion (or embolisation) consists in occluding one or several vessels which are causing haemoptysis. Either of the pulmonary circulations (systemic bronchial or pulmonary) may be the cause and sometimes both are. In systemic pulmonary hypervascularization the pathological issues are affected by high pressure vascularisation at the expense of functional vascularisation and are the source of frequent episodes of bleeding. Bronchial and systemic vaso-occlusion has proven efficacy and safety on condition that strict rules are respected to avoid complications; the detection of potentially dangerous arteries (spinal, coronary and visceral) and a choice of material for embolisation which is adapted to the therapeutic strategy and the clinical and angiographic presentation. The indications for the procedure are dictated by severe or recurrent haemoptysis. Vaso-occlusion of pulmonary arteries which is a rarer indication dominated by conditions such as arteriovenous malformation (MAVP). The technique is adapted to the number, to the size and to the diffusion of MAVP which is characterised precisely by computed tomography. Vaso-occlusion is the treatment of first choice for MAVP only leaving failures of vaso-occlusion to surgery and certain pedicular forms have a very short afferent of large calibre.

Anomalous origin of the left coronary artery arising from the pulmonary trunk: report of an adult case with long-term follow-up after surgery

An anomalous origin of the left coronary artery arising from the pulmonary artery is a congenital malformation rarely described in adults. We report the case of a 65-year-old patient with this anomaly. Clinical presentation, imaging identification (coronary angiogram, MRI and electron-beam CT), surgical treatment and angiographic long-term follow-up are described.

[Helical computed tomography of the aorta and its branches]

Imaging of the aorta has greatly benefited from the recent development of helical computed tomography. This noninvasive and widespread imaging technique could be considered as a viable alternative to invasive modalities in aortic disease assessment, especially in the acute onset. Radiologists should be familiar with the principles of this technique and its clinical applications. This report develops technical aspects, typical and atypical features of a variety of noncongenital aortic diseases including dissections, aortic trauma, aneurysms, nonaneurysmal atherosclerotic diseases and arteritis. The role of helical CT as noninvasive tool for imaging the aorta and its branches is compared to the other imaging methods.

Estimation of gas and tissue lung volumes by MRI: functional approach of lung imaging

PURPOSE

The purpose of this work was to assess the accuracy of MRI for the determination of lung gas and tissue volumes.

METHOD

Fifteen healthy subjects underwent MRI of the thorax and pulmonary function tests [vital capacity (VC) and total lung capacity (TLC)] in the supine position. MR examinations were performed at inspiration and expiration. Lung volumes were measured by a previously validated technique on phantoms. Both individual and total lung volumes and capacities were calculated. MRI total vital capacity (VC(MRI)) was compared with spirometric vital capacity (VC(SP)). Capacities were correlated to lung volumes. Tissue volume (V(T)) was estimated as the difference between the total lung volume at full inspiration and the TLC.

RESULTS

No significant difference was seen between VC(MRI) and VC(SP). Individual capacities were well correlated (r = 0.9) to static volume at full inspiration. The V(T) was estimated to be 836+/-393 ml.

CONCLUSION

This preliminary study demonstrates that MRI can accurately estimate lung gas and tissue volumes. The proposed approach appears well suited for functional imaging of the lung.

[Arterial lipiodol chemoembolization of a left liver metastasis through the right internal thoracic artery]

The purpose of this article is to illustrate the efficacy of the chemoembolization in patients with hypervascular metastases and to describe the post-embolization change in vascularization pattern. Unusual collaterals may develop following embolization. A 59-year-old woman, followed for unresectable small bowel carcinoid tumor since 1991, underwent successful chemoembolization of several liver metastases. Only one liver lesion, located in segment IV, showed interval increase in size. This lesion was supplied by the right internal mammary artery. A branch of the right internal mammary artery was catheterized using a microcatheter and embolization was performed using doxorubicine-Lipiodol (Adriblastine, Lipiodol) and gelfoam (Spongel). No complications occurred after the procedure. The right internal mammary artery should be considered as a possible source of collateral arterial supply to the liver and should be evaluated in patients with local progression of disease.

Percutaneous gastrostomy for enteral nutrition: long-term follow-up of 176 procedures

OBJECTIVE

To evaluate the efficacy and safety of percutaneous gastrostomy (PG), using small catheters without gastropexy, to deliver enteral nutrition.

METHODS

We reviewed the records of 176 consecutive patients in whom PG was attempted for enteral nutrition. Of these cases, 172 catheters were inserted by the Seldinger technique under fluoroscopic guidance alone, 2 were inserted under computed tomographic guidance, and 2 procedures failed. In primary procedures, 8.5- or 10.2-French catheters were used.

RESULTS

The technical success rate was 98.9%. Of the 176 procedures, 2 failed because of the high position of the stomach. Seven-day follow-up was obtained in all patients; 30-day follow-up in 145 patients (83%), and long-term follow-up (30 to 1512 days) in 123 patients (70%). The 30-day mortality rate was 13.2%. One death (0.5%) was directly related to the procedure. Major complications occurred in 4 patients (2.2%), and minor complications in 12 patients (6.9%). No patient required surgery for complications attributable to the gastrostomy procedure.

CONCLUSION

PG without gastropexy using small catheters is a simple, safe and effective technique for delivering enteral nutrition.

Life-threatening spontaneous psoas haematoma treated by transcatheter arterial embolization

We report two cases of large spontaneous psoas haematoma in patients on anticoagulant therapy. Active bleeding was well demonstrated on spiral CT. Transcatheter arterial embolization was used successfully to stop bleeding. The diagnostic strategy, the relevance of spiral computed tomography and our therapeutic approach to this complication are discussed.

Subacute and chronic benign superior vena cava obstructions: endovascular treatment with self-expanding metallic stents

OBJECTIVE

Our purpose is to report our clinical experience with patients who underwent endovascular treatment with Wallstents for subacute or chronic benign obstruction of the superior vena cava (SVC).

SUBJECTS AND METHODS

Twelve patients who were an average of 54 +/- 12 years old were referred for treatment of severe SVC syndrome related to implanted central venous catheters (n = 8), postradiation fibrosis (n = 2), a permanent pacemaker (n = 1), or a benign tumor (n = 1). Symptoms were present for an average of 16 weeks (range, 4-48 weeks) before treatment. Diagnosis of SVC obstruction was confirmed with helical CT and pretherapeutic phlebography. Four patients had Stanford's type II stenosis; two, type III; and six, type IV. The mean clinical and radiologic follow-up intervals were 11 months (range, 1-36 months) and 7 months (range, 1 week to 32 months), respectively.

RESULTS

Recanalization was successful in all patients. Fifteen stents were implanted in the 12 patients. Stents were placed after percutaneous balloon angioplasty in nine patients, and primary stent placement was attempted in three patients. We immediately achieved a satisfactory SVC diameter in all patients, whose symptoms were relieved completely within 1 week of stent placement. No technical or clinical complications occurred. SVC syndrome recurred in one patient 2 months after stent placement and was treated by placing a second stent.

CONCLUSION

Endovascular treatment with stent placement should be considered relevant and safe for refractory benign SVC syndrome. However, a larger series and a longer follow-up period are needed to define the role of stent placement for this syndrome.

[Post-traumatic aneurysmal dissection of the extracranial internal carotid artery; helical computed tomographic and angiographic aspects: a case]

A 20-year-old man presented with mild intracranial bleeding, a Horner's syndrome, and left neck swelling following head injury. Following noncontrast CT of the brain, a contrast-enhanced helical CT was performed through the neck that showed a hematoma in the poststyloid space (carotid sheath) with irregular diameter of the ICA. Selective digital subtraction angiography confirmed the presence of left cervical ICA dissection with pseudoaneurysm formation. The aneurysm was resected and an end-to-end anastomosis was done using an inverted saphenous graft. Histology confirmed a diagnosis of traumatic ICA dissection with pseudoaneurysm formation and there was no evidence of pre-existing pathology. Helical CT is a simple, widely available, and relatively non-invasive imaging technique that correlates well with angiography. It should be considered in the evaluation of patients with suspected cervical ICA dissection.

Brain "embolism" detected by magnetic resonance imaging during percutaneous mitral balloon commissurotomy

PURPOSE

The common finding of thrombi between the bifoil balloons when they were extracted after mitral dilation prompted us to look for evidence of minor brain embolisms using the sensitive technique of BMRI (brain magnetic resonance T2-weighted imaging).

METHODS

BMRI was performed within 48 hr before and after a percutaneous mitral balloon commissurotomy (PMBC) in each of the 63 patients in this study.

RESULTS

There was evidence (hyperintensity foci: HI) of a previous asymptomatic brain embolism in 38 of 63 patients before PMBC and a new HI appeared in 18 of 63 patients after the procedure. New HI signals were found exclusively in the white matter in 8 of 18 patients and in only 3 of 18 were HI signs larger than 1 cm. One patient, with an HI signal > 1 cm in the thalamus and another < 1 cm in the brain stem, presented diplopia accompanied by other minor clinical signs. The differences in HI rate among four subgroups (1, older vs younger than 43 years; 2, sinus rhythm vs atrial fibrillation; 3, echo score < 8 vs > 8; 4, patients from western countries vs the others) were not statistically significant, probably because the number of patients in each subgroup was low. Patients in atrial fibrillation had slightly more (not significant) HI before PMBC (15/20, 75%) than patients in sinus rhythm (23/43, 53%), but after PMBC their HI frequencies were similar (atrial fibrillation: 5/20, 25%; sinus rhythm: 13/43, 30%).

CONCLUSION

Brain microembolism is frequent during PMBC, but is often anatomically limited and free from clinical signs in most cases. Brain embolism seems to be related mainly to the procedure itself and not the features of the patient.

Helical CT phlebography of the superior vena cava: diagnosis and evaluation of venous obstruction

OBJECTIVE

The purpose of this study was to determine the feasibility of helical CT phlebography of the superior vena cava (SVC) and to evaluate the role of this imaging technique in the diagnosis and treatment of SVC obstruction.

SUBJECTS AND METHODS

Twenty-three helical CT phlebograms were obtained of patients with clinical findings that were suggestive of SVC obstruction (n = 19) and of patients undergoing posttherapeutic evaluation for SVC obstruction (n = 4). CT examinations consisted of helical acquisitions obtained in the craniocaudal direction with simultaneous bilateral antecubital vein injection of 2 x 90 ml of 12% iodinated contrast material at 2 ml/sec. Combined analysis of axial, multiplanar, and maximum-intensity-projection reformatted images was used for all patients. Image quality, venous stenosis or obstruction, intraluminal thrombus, and collateral pathways were evaluated. Comparison with digital phlebographic data was available for 16 patients; this comparison was performed in a nonblinded manner.

RESULTS

CT phlebograms were considered technically optimal in 91% of the patients. In all these patients, helical CT phlebograms showed the venous obstruction: the site, extent, cause, and collateral pathways. CT phlebography appeared to be well correlated with digital phlebography in 16 patients regarding the degree of obstruction, the presence of collateral pathways, and the presence of thrombus.

CONCLUSION

Helical CT phlebography may be a useful technique for imaging the SVC and its tributaries. This imaging technique is simple to perform and can provide all the information necessary to diagnose and treat SVC obstruction.

[Preoperative angiographic landmarks of the gluteal muscle regions using Patent Blue V]

Use of a gluteus musculocutaneous flap is the most reliable technique for surgical repair of sacral ulcers. Surgery could be ideally performed when the flap is designed using only the upper or the lower half of the glutens maximus muscle depending on the superior gluteal artery or the inferior gluteal artery, respectively. The authors have developed a technique for preoperative demonstration of the vascular supply to both muscle and overlying skin from a single gluteal artery using superselective catheterization and arterial administration of a dye (Patent Blue V). This technique facilitates the surgical procedure but assessment of its usefulness will require further evaluation.

Brain "embolism" detected by magnetic resonance imaging during percutaneous mitral balloon commissurotomy

PURPOSE

The common finding of thrombi between the bifoil balloons when they were extracted after mitral dilation prompted us to look for evidence of minor brain embolisms using the sensitive technique of BMRI (brain magnetic resonance T2-weighted imaging).

METHODS

BMRI was performed within 48 hr before and after a percutaneous mitral balloon commissurotomy (PMBC) in each of the 63 patients in this study.

RESULTS

There was evidence (hyperintensity foci: HI) of a previous asymptomatic brain embolism in 38 of 63 patients before PMBC and a new HI appeared in 18 of 63 patients after the procedure. New HI signals were found exclusively in the white matter in 8 of 18 patients and in only 3 of 18 were HI signs larger than 1 cm. One patient, with an HI signal >1 cm in the thalamus and another <1 cm in the brain stem, presented diplopia accompanied by other minor clinical signs. The differences in HI rate among four subgroups (1, older vs younger than 43 years; 2, sinus rhythm vs atrial fibrillation; 3, echo score <8 vs >8; 4, patients from western countries vs the others) were not statistically significant, probably because the number of patients in each subgroup was low. Patients in atrial fibrillation had slightly more (not significant) HI before PMBC (15/20, 75%) than patients in sinus rhythm (23/43, 53%), but after PMBC their HI frequencies were similar (atrial fibrillation: 5/20, 25%; sinus rhythm: 13/43, 30%).

CONCLUSION

Brain microembolism is frequent during PMBC, but is often anatomically limited and free from clinical signs in most cases. Brain embolism seems to be related mainly to the procedure itself and not the features of the patient.

Motion artifacts of the aorta simulating aortic dissection on spiral CT

PURPOSE

Motion artifacts of the ascending aorta may impair image quality and simulate an intimal flap or a false channel. The purpose of this study is to evaluate the prevalence, amplitude, and extent of motion artifacts of the aorta in spiral CT and to specify the effects of acquisition and reconstruction parameters on these artifacts.

METHOD

One hundred seventy-one thoracic spiral CT examinations were retrospectively analyzed by two reviewers. The analysis sought to determine the presence, location, amplitude, and extent of artifacts of the ascending aorta.

RESULTS

Aortic artifacts were detected on spiral CT in 57% of cases. The mean amplitude and mean extent were 4+/-4 and 6+/-7 mm, respectively. Artifacts in the ascending aorta were significantly higher with the 360 degrees linear interpolation (LI) algorithm than with the 180 degrees LI algorithm.

CONCLUSION

The prevalence of motion artifacts on spiral CT is higher in this study than the reported prevalence in incremental CT. However, this higher prevalence is significantly reduced when the 180 degrees LI algorithm is used.

[Positional occlusion of the descending scapular artery in transverse thoraco-brachial syndrome with neurologic symptoms]

We report a thoracic outlet syndrome revealed by neurological complications. Angiography of the subclavian artery depicted an isolated positional occlusion of the descending scapular artery. This side branch of the subclavian artery is anatomically located close to and supplies the brachial plexus. Surgical treatment led to improvement of most symptoms and post-operative control angiography was normal. Not previously described, this sign illustrates the objective compression of the brachial plexus. Ischemia is perhaps intricated with compression, a well-known pathophysiological mechanism of neurological complications in this syndrome. This artery feeding the brachial plexus is usually ligated during surgical neurolysis but must be preserved in order to improve recovery of neurological function and prevent surgical failures.

[The value of transesophageal echocardiography for the diagnosis of pulmonary embolism with acute pulmonary heart disease]

Transoesophageal echocardiography is a method of visualising intracardiac thrombi and could therefore be useful for the diagnosis of pulmonary embolism, but its diagnostic value is unknown. The authors carried out a prospective study with this diagnostic tool in massive pulmonary embolism. The study protocol was to perform transthoracic echocardiography in patients with suspected acute pulmonary embolism and then to perform transoesophageal echocardiography when there were signs of acute cor pulmonale. The results of both echocardiographic investigations were compared with two reference radiological techniques: the spiral CT scan and/or pulmonary angiography. Fifty-six patients underwent transthoracic echocardiography. In the 34 patients with transthoracic echocardiographic signs of acute cor pulmonale, the positive predictive value of the investigation for pulmonary embolism was 91% and the negative predictive value was 54%. Twenty of these 34 patients underwent transoesophageal echocardiography. The sensitivity and specificity for the diagnosis of proximal embolism were 85% and 86% respectively. The limitations of the method were poor visualisation of the left pulmonary artery in which only one thrombus was detected, compared with 6 by spiral CT scan, and the absence of visualisation of lobar arteries. Consequently, the real sensitivity of transoesophageal echocardiography for visualisation of all thrombi in the pulmonary arteries in acute cor pulmonale was only 55%. In acute cor pulmonale, the diagnostic value of transoesophageal echocardiography is poor because the sensitivity for visualisation of intra-pulmonary arterial thrombi is low compared with other radiological techniques. However, in patients with proximal emboli in the right or main pulmonary artery, the diagnosis may be established in a few minutes without the need of other more invasive techniques. Nevertheless, normal transoesophageal echocardiography does not rule out the presence of proximal in the left pulmonary artery or distal emboli in the lobar arteries.