Improvement of determination technique for extracting centerline in coronary artery with calcification on CTA.

The present study proposes a method for improving an existing technique used for extracting the centerlines of coronary arteries with calcifications on CTA. Through the use of the improved centerline extraction method, CPR images could be depicted accurately. In the proposed method, two dynamic range compression algorithms using two ITC for blood vessel regions and calcification regions were employed. Two dynamic range compressed CTA images obtained from the two ITC were then subtracted. After that, automatic tracing to determine the centerline for creating CPR images was performed using 3D image processing equipment. The usefulness of our proposed method was confirmed by using simulated CTA of the coronary artery with calcification. We also applied the proposed method to CTA images of 39 branches in 18 cases, and to 48 segments. Our experimental results showed that automatic tracing software pre-installed in the workstation could accurately determine the centerline of the coronary artery without being affected by the existence of calcification. Furthermore, an experienced radiological technologist evaluated the CPR images obtained by the proposed method. The results showed that most created CPR images could be used as diagnostic images after a minor revision performed manually.

Endovascular treatment of spontaneous isolated dissecting aneurysm of the superior mesenteric artery using stent-assisted coil embolization.

Spontaneous isolated dissecting aneurysm of the main trunk of the superior mesenteric artery is a rare condition. We treated a patient with this condition successfully by stent-assisted coil embolization. Intravascular stent placement may widen the indications for endovascular coiling of the aneurysmal false lumen to avoid perforation.

Two-phase CT pulmonary angiography for detection of hilar pulmonary thromboembolism.

PURPOSE: To assess the usefulness of two-phase CT pulmonary angiography (CTPA) for patients with suspected pulmonary thromboembolism (PE). MATERIALS AND METHODS: Forty-four patients (in 48 studies) underwent two-phase CTPA. Fifteen sec after the injection of contrast material, an entire thorax scan was performed, and in the second phase the hilar territory was rescanned after a 15-sec delay. In the first phase, 25 subjects were scanned cranio-caudally (group A), and 23 caudal-cranially (group B). The mean attenuation values of the main pulmonary artery (MPA) and the ascending aorta (Ao) were measured. Perivenous artifacts in the right pulmonary artery (RPA) were also graded using a 4-point scale. RESULTS: The mean attenuation values in the MPA and Ao were higher in the first phase than in the second phase. The perivenous artifact scores at the first phase in groups A and B were severe in 12 and 15, moderate in 8 and 7, minimal in 4 and 1, and none in 1 and 0. The scores at the second phase were none in all cases. CONCLUSION: Two-phase CTPA produced good opacification of the RPA without major perivenous artifact and proved useful in the detection of PE in these areas.

Urokinase lysis for acute left subclavian artery thrombosis after placement of infusion catheter: report of two cases.

We present two cases of acute subclavian and/or axillary arterial occlusion after transaxillary catheterization with an implantable port for hepatic arterial infusion chemotherapy. They were successfully treated with thrombolytic therapy using intraarterial administration of urokinase without removal of the infusion catheter system. We consider that this treatment is suitable for managing acute thrombosis of the conduit artery after catheterization for hepatic arterial infusion chemotherapy.