Role of multi-slice computed tomography angiography in the diagnosis of visceral artery aneurysms / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the value of multi-slice computed tomography angiography (MSCTA) in the diagnosis of visceral artery aneurysms (VAA).</p><p><b>METHODS</b>The imaging data of 123 VAA patients who received abdominal contrasted CT and MSCTA on the PACS workstation in our department from May 2008 to October 2010 were retrospectively analyzed. Based on the findings of comprehensive evaluation and using vessels as the analytic unit, we evaluated the sensitivity and specificity of enhanced axial images and post-processing images in detect the VAA.</p><p><b>RESULTS</b>Totally 172 VAAs were found in these 123 patients by the comprehensive evaluation, among which 107 were diagnosed by MSCTA.The results included 91 splenic artery aneurysms, 16 renal artery aneurysms, 8 multi-visceral artery aneurysms, 2 gastric artery aneurysms, 2 superior mesenteric artery aneurysms, 1 celiac trunk aneurysm, 1 gastroduodenal artery aneurysm, 1 pancreaticoduodenal artery aneurysm, and 1 hepatic artery aneurysm. The sensitivity and specificity of MSCTA in diagnosing TAA was 100% and 100%, respectively.</p><p><b>CONCLUSION</b>With different reconstruction methods, MSCTA can accurately and clearly display the location, shape, extent, aneurysmal wall, parent artery, and relationship with the adjacent vessels of VAAs.</p>

Value of enhanced computed tomography in the diagnosis of adrenal hemangioma / 中国医学科学院学报

<p><b>OBJECTIVE</b>To summarize the computed tomography (CT) findings of adrenal hemangioma.</p><p><b>METHOD</b>The CT findings of 9 patients with pathologically proved adrenal hemangioma from June 2008 to March 2011 were retrospectively reviewed.</p><p><b>RESULTS</b>All the tumors were located unilaterally, with 4 in the left and 5 in the right. The tumors were 1.5-8.4 cm in size with complete capsule and well-defined contour. Among these nine tumors, six were round or ovoid, while the other three had irregular shapes. Plain scan showed mixed density in 8 and cystic change in 1. After contrast enhancement, six tumors manifested with inhomogeneous enhancement and the other three without enhancement. For three cases who underwent multi-phase enhanced CT scans, irregular enhancement at the periphery of the masses were showed in artery phase, and centripetal filling with contrast medium to the center of masses were showed in the portal and delayed phases.</p><p><b>CONCLUSIONS</b>Hemangioma is a rare benign tumor of the adrenal gland. CT findings are diverse, and the preoperative misdiagnosing rate can be high. Multi-phase enhanced CT scan may show characteristic features of adrenal hemangioma and help achieve correct preoperative diagnosis.</p>

Clinical application of dual-source computed tomographic urography using dual-energy virtual non enhanced computed tomography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the clinical feasibility of dual-source computed tomographic urography using dual-energy virtual non-enhanced CT.</p><p><b>METHODS</b>Totally 240 patients received dual-source CT, which included true non-enhanced CT (TNCT) , nephrographic phase scanning with dual-energy mode (100kVp/230mAs and Sn140kVp/178mAs) , and excretory phase scanning. A contrast bolus injection of 100 ml (370 mgI/ml) contrast agent was applied (4.5ml/s) , followed by 100ml normal saline (4.5ml/s) . Virtual non-enhanced CT (VNCT) image sets were reformatted from 'Liver VNC ' software. The mean CT number, noise, signal to noise ratio (SNR) , image quality, and radiation dose were compared between TNCT and VNCT image sets.</p><p><b>RESULTS</b>There was no significant difference in mean CT numbers of all organs (P>0.05) . However, VNCT images had significantly lower noise and higher SNR than TNCT images (both P<0.05) . Image quality of VNCT was lower than that of TNCT without significant difference (P>0.05) . Radiation dose of nephrographic phase with dual-energy mode was significantly higher than that of TNCT and excretory phase scanning (P<0.05) .</p><p><b>CONCLUSION</b>Dual-energy VNCT requires less radiation dose and therefore has a potential to replace TNCT in the dual-source CT urography.</p>

Dual-energy computed tomographic angiography of head and neck arteries with different contrast material doses in second generation dual-source computed tomography system / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the feasibility of a dual-energy computed tomographic angiography (DECTA) protocol using test-bolus injection with reduction of contrast material (CM) dose in second generation dual-source CT system.</p><p><b>METHODS</b>Totally 57 consecutive patients underwent CT angiography scan covering the cervical and cerebral arteries. CT was performed with second generation dual-source CT system. The time to peak (T) using a test-bolus injection was calculated. The patients were divided into three groups (A, B, and C) with different CM doses (40, 45, and 50 ml) and different delay time points [ (T+1) , (T+1) , and (T+2) s] . All the patients were followed by a 48 ml saline flush. Arterial enhancements were quantified by measuring attenuation values of the aortic arch, bifurcation of common carotid artery, contralateral internal jugular vein of the CM injection, superior vein cava, proximal middle cerebral artery, basilar artery, and straight sinus on source images. Visualizations of intracranial artery and ipsilateral venous effect of the CM injection were rated on a four-point grading scale on CTA images for qualitative assessment.</p><p><b>RESULTS</b>Although the attenuation of internal jugular vein and straight sinus were significantly lower in group A than in groups B and C (P<0.05) , the attenuation of aortic arch, superior vein cava, common carotid artery, middle cerebral artery, and basilar artery vessels showed no significant differences among these three groups. The scores of the visualizations of intracranial artery and ipsilateral venous effect of the CM injection were also not significantly different among these three groups.</p><p><b>CONCLUSION</b>Based on the delay time calculated by a test-bolus injection, a reduced-dose contrast material may provide an equal degree of arterial attenuation and a lower attenuation of vein for dual-energy CTA covering the craniocervical region in second generation dual-source CT system.</p>