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.