Demonstration of pulmonary embolism with gadolinium-enhanced spiral CT.

The authors report a case of successful detection of pulmonary embolism using gadolinium-enhanced spiral CT (Gadodiamide, 0.4 mmol/kg, 2 ml/s, delay 18 s) in a 77-year-old woman, with previous allergy to iodinated contrast medium, and renal failure, who presented with pulmonary arterial hypertension. Doppler ultrasound of the lower limbs was first performed and revealed a deep venous thrombosis of the right lower limb. To establish if venous thrombosis was the cause of pulmonary hypertension and to confirm that pulmonary endarterectomy was not indicated in this situation, several imaging modalities were performed. Lung scintigraphy and MRI were non-diagnostic. Gadolinium-enhanced spiral CT demonstrated a large thrombus located proximally and in a segmental artery of the right lower lobe. This case illustrates the potential usefulness of gadolinium as alternative contrast agent with spiral CT to diagnose pulmonary embolism and elucidate the cause of pulmonary arterial hypertension in a patient with some contraindications for iodinated contrast medium injection.

Ethanol sclerotherapy of venous malformations: evaluation of systemic ethanol contamination.

PURPOSE: To evaluate blood ethanol concentrations immediately after percutaneous ethanol sclerotherapy of venous malformations (VMs). MATERIALS AND METHODS: Thirty consecutive sclerotherapy procedures were performed for VMs in various anatomic sites. In a prospective study, the blood parameters monitored were ethanol plasma level (immediately after the procedure), plasma haptoglobin (Hp; before and after the procedure), and standard blood analysis including urea, creatinine, bilirubin, and lactic dehydrogenase (LDH) levels during the hospital stay. RESULTS: The mean amount of 94% ethanol injected was 19.7 mL (0.03-0.78 g/kg of body weight). The observed systemic ethanol levels ranged from 0 to 1.16 g/L (mean, 0.33 g/L, SD = 0.33). The relationship between the observed plasmatic ethanol level (ETOH plasma) measured immediately after the procedure and the maximum expected plasmatic ethanol amount (ETOH max) was linear and significant (correlation coefficient r = 0.91 for all lesions, r = 0.96 for lesions without visible venous drainage, r = 0.86 for lesions with visible draining veins, and r = 0.93 for lobulated VMs). Minimal changes were observed for indicators of hemolysis: macroscopic hemoglobinuria in five of 30, abnormal Hp level in seven of 30, and increase in LDH and increase in bilirubinemia in one case each. CONCLUSIONS: Systemic ethanol contamination during sclerotherapy of VMs could be detected in 25 of 30 cases (83.3%). The plasmatic ethanol level was directly proportional to the amount of ethanol injected and not dependent on the VM morphology, venous drainage, or injection technique. Clinicians and interventional radiologists must be aware of this massive ethanol outflow during percutaneous sclerotherapy of VMs and its potentially serious systemic complications.

Using dual-detector helical CT angiography to detect deep venous thrombosis in patients with suspicion of pulmonary embolism: diagnostic value and additional findings.

OBJECTIVE: The purpose of this study was to assess the value of dual-slice helical CT angiography in detecting deep venous thrombosis in patients in whom acute pulmonary embolism was suspected and to describe the additional extrathoracic findings. SUBJECTS AND METHODS: Sixty-five consecutive patients were examined for suspected pulmonary embolism using helical CT of the chest (2.7-mm collimation; table speed, 7.5 mm/sec; 100-140 mL of contrast medium injected at a rate of 3 mL/sec) followed by CT of the lower limbs (6.5-mm collimation; table speed, 10 mm/sec) without any additional contrast medium injection. Sequential scanning of the abdomen was performed using 10-mm collimation and an interval of 40 mm. Color Doppler sonography of the lower limbs was done within 24 hr of CT by two radiologists who were unaware of CT findings. Results of CT venography were compared with those of Doppler sonography and with phlebography or repeated focalized sonography in cases of discrepancy. RESULTS: Twenty-two patients had pulmonary embolism revealed on chest CT. Sixteen patients had a deep venous thrombosis. Thirteen patients with pulmonary embolism had a deep venous thrombosis. Three patients with deep venous thrombosis had no pulmonary embolism. Sensitivity and specificity for diagnosing deep venous thrombosis with CT was 93% and 97%, respectively (kappa = 0.88). Additional extrathoracic findings were observed in four patients. CONCLUSION: Combined CT venography with dual-slice scanning is an accurate method to diagnose deep venous thrombosis that may reveal additional imaging findings in some patients with possible pulmonary embolism.

Pseudo-occlusion of the external iliac artery after stenting.

A patient with an unknown thoracic aortic coarctation underwent angiography for calf claudication. Percutaneous angioplasty and stenting of an external iliac artery (EIA) stenosis produced flow reversal in the EIA, mimicking occlusion on the angiogram. This aberrant situation resulted from a haemodynamic disbalance between the iliac flow and a dominant compensatory collateral flow through the inferior mammary-epigastric channel produced by the coarctation.

Gadolinium dimeglumine: an alternative contrast agent for digital subtraction angiography.

The aim of this study was to evaluate gadolinium diethylenetriaminepenta-acetic acid (Gd-DTPA) as an alternative contrast agent for digital subtraction angiography (DSA) in patients with renal insufficiency or previous anaphylactic reaction to iodinated contrast agents. We performed 34 DSAs in 31 patients by use of the commercially available 0.5-M Gd-DTPA solution (Magnevist, Schering, Berlin, Germany). The contrast material was power- or hand-injected at the same rate as iodinated contrast material, without exceeding a total amount of 0.4 mmol/kg body weight. In 18 studies Gd-DTPA was the sole contrast agent. In 9 cases gadolinium injections were combined with carbon dioxide. Restricted non-ionic contrast medium injections were administered to complete the examinations in 7 cases and for comparative purposes in 1 case. Cerebral and carotid arteries, one superior limb, abdominal aorta, renal arteries, renal transplants, iliac arteries and inferior limbs were imaged, and ten endovascular interventional procedures, including three transjugular intrahepatic percutaneous stent shunts, were performed. No side effects were observed. Diagnostic angiographic images were obtained in all cases except in 5 of the 8 distal run-off studies. Gadolinium-based contrast can produce clinically useful angiograms in patients with a contra-indication to iodine who must undergo angiography.

Glue embolisation of a ruptured pancreaticoduodenal artery aneurysm.

Embolisation of a mycotic aneurysm of the anterior pancreaticoduodenal arcade was performed in an emergency situation using a microcatheter and tissue adhesive, after unsuccessful surgical therapy. The polymerising agent occluded the outflow vessel, the aneurysm and the feeding artery successfully.

In vitro evaluation of vena cava filters.

PURPOSE: The authors tested in vitro nine caval filters to evaluate clot-trapping capacity and transfilter pressure gradients under varying experimental conditions. MATERIAL AND METHODS: The filtering efficiency of the stainless-steel Greenfield filter was evaluated in a modified flow model. A total of 2,100 clots were injected. In addition, controlled parameters simulating in vivo conditions were selected to appreciate clot-trapping capacity and pressure gradients for nine filters in horizontal and vertical positions, by using small (3 x 30 mm) and medium-sized (5 x 30 mm) clots. Statistical evaluation was performed for 3,600 clot deliveries. RESULTS: Depending on experimental conditions, the clot-trapping capacity of the Greenfield filter varied greatly (0%-78%) by using small and medium clots. Bird's Nest and Simon nitinol filters demonstrated the highest filtering efficiency (94%-100%) for small clots. Medium clots were effectively captured by Bird's Nest, Simon nitinol, Antheor, and Günther Tulip filters (79%-100%). CONCLUSION: Experimental parameters influence a filter's clot-trapping capacity. Bird's Nest filters demonstrated the highest clot-trapping capacity.