Application of three-dimensional contrast-enhanced MR angiography in the diagnosis and treatment of aortic coarctation / 中华胸心血管外科杂志

Objective To evaluate the clinical value of three-dimensional contrast-enhanced MR angiography (3D CE-MRA) in the diagnosis and treatment of aortic coarctation. Methods Twenty-one patients with aortic coarctation underwent 3D CE-MRA with a 3D FLASH sequence after injection of 0.2 mmol Gd-DTPA per kg b. w. The source images were subtracted and transferred to computer workstation subsequently post-procession. In six patients, cardioangiography was performed simultaneously. The diagnoses of all patients of them were proven by surgery. Results There were 6 cases (28.6%) of simple type of aortic coarctation and 15 (71.4%) accompanied other cardiovascular abnormalities. 3D CE-MRA could directly demonstrate the stenotic location, degree, extent and extracardiac vascular abnormalities, which accorded with surgical findings. The depiction of the entirety and collateral vessel formation was very helpful for surgery. It can be easier for pre- and post- operative evaluation. Conclusion 3D CE-MRA is a noninvasive and accurate technique in the diagnosis of aortic coarctation. It could replace the cardioangiography for extracardiac vascular abnormalities, and may be one of the first choice examinations.

Carbon Dioxide Digital Subtraction Angiography in Percutaneous Sclerotherapy of Venous Hemangiomas

PURPOSE: To investigate the usefulness of carbon dioxide digital subtraction angiography (CO2-DSA) in direct puncture sclerotherapy of venous hemangiomas involving extremities. MATERIALS AND METHODS: Direct puncture sclerotherapy was performed in 12 patients with venous hemangioma of extremities. After direct puncture of the hemangiomas, 30-50 cc of CO2 was manually injected and digital subtraction angiograms were obtained. If draining vein was visualized, a tourniquet was applied at the proximal site to compress the draining veins. There after, radiopaque embolic materials such as 1:3 mixture of Lipiodol and absolute ethanol or ethanolamineoleate-Lipiodol-Avitene (microfibrillar collagen hemostat) mixture were slowly injected under the fluoroscopic guidance. RESULTS: Rapid injection of large amount of a CO2 enabled the visualization of wide areas of venous hemangiomas in 11 patients. Draining veins were reliably demonstrated in 10 patients and pulmonary embolism of embolic materials was effectively prevented by proximal tourniquet application. Because of radiolucent nature of CO2 retained in hemangiomas, we could clearly identify the distribution of radiopaque embolic materials under fluoroscopy. Retained CO2 also could be used as a guide for additional multiple puncture of hemangiomas. There was no systemic symptoms or complications related to CO2-DSA. CONCLUSION: CO2-DSA is a convenient, safe and useful angiographic technique in direct puncture sclerotherapy of hemangiomas involving extremities.

Carbon Dioxide as a Venous Contrast Agent: Applications in Interventional Radiology

PURPOSE: To evaluate the safety and usefulness of carbon dioxide (CO2) as a venous contrast agent for upper-arm placement of peripherally inserted central venous catheter (PICC), vena caval filter placement, and for visualization of the portal vein in transjugular intrahepatic portosystemic shunt (TIPS). MATERIALS AND METHODS: About 20-30ml of CO2 was used as an alternative to iodinated contrast material for digital subtraction angiography (DSA) and fluoroscopy to guide upper-arm placement of PICC in 46 patients, for inferior venacavogram before filter placement in five, and for visualization of the portal vein during TIPS in two. Vital signs, peripheral arterial oxygen saturation, and renal function were checked during and after delivery of CO2. RESULTS: All CO2 DSA for PICC placement clearly delineated patency or stenosis of the central veins. In 41 of 46 patients (89%), PICC placement with CO2 guidance was successful. The mean number of venipunctures for PICC placement was 1.9, and the mean volume of CO2 injected for venipuncture was 35 ml. In five patients, Titanium Greenfield filters were successfully implanted into the inferior vena cava following CO2 vena cavography. In two patients in whom hepatopetal portal flow was seen on indirect portography, the portal vein was visualized by CO2-wedged hepatic venography. Injection of CO2 into the splenic vein following TIPS placement revealed shunt patency. Vital signs and oxygen saturation did not change, and there was no evidence of renal toxicity following CO2 injection. CONCLUSION: CO2 is a safe and useful alternative contrast agent for upper-arm placement of PICC, pre-filter placement cavography, and wedged hepatic venography and portography for TIPS.