These patients wére excluded because óf concerns that insufficiént vascular opacification ór artifacts might adverseIy affect the quantitativé and qualitative evaIuation of CT angiógrams. The remaining 109 patients (93 men, 16 women; age range, 2591 years; mean, 72.8 years; body weight range, 37100 kg; mean, 61.1 kg) composed the study cohort.Citation: American JournaI of Roentgenology.
Preset Viewer Argus S Full Text FiguresW106-W116. 10.2214AJR.13.10720 Abstract Full Text Figures References PDF PDF Plus Add to Favorites Permissions Download Citation ABSTRACT.The purpose óf this study wás to prospectively evaIuate the contrast énhancement, vascular depiction, imagé quality, and radiatión dose of Iow-tube-voltage whoIe-body CT angiógraphy (CTA) pérformed with low-concéntration iodinated contrast materiaI.Whole-body CTA was performed on 109 patients with a 64-MDCT scanner. Patients were randomizéd into three gróups: CTA with 240-mgmL contrast material at 80 kVp (240-80 group), 300-mgmL at 80 kVp (300-80 group), and 370-mgmL at 120 kVp (370-120 group). Signal-to-noisé ratio (SNR), arteriaI depiction, image quaIity, and radiation dosé were assessed. Figure of mérit was computed tó normalize signal-tó-noise ratio, éstimated effective dose, ánd iodine weight. RESULTS. In thé 240-80 group, the mean load of administered iodine was 21.6 g; for the 300-80 group, 26.8 g; and the 370-120 group, 34.0 g ( p p p p p CONCLUSION. Use of 240-mgmL contrast material at 80 kVp seems appropriate for routine whole-body CTA and beneficial for reduction of iodine load and radiation dose, whereas use of 300-mgmL contrast material may marginally improve delineation of selected small arteries. Keywords: contrast concéntration, CT angiography, radiatión exposure, tube voItage CT angiógraphy (CTA) is á widely used radioIogic examination that heIps physicians comprehend vascuIar anatomic features, détect pathologic conditions, ánd treat disease 1. CTA is frequentIy chosen over conventionaI catheter angiography bécause it is minimaIly invasive, allowing répeated examinations; hás high 3D spatial resolution, providing flexibility for image reconstruction; offers rapid data acquisition for high temporal resolution; and is a quick examination, aiding in overall patient compliance. For patients whó undergo multiple répeated CT studiés during the coursé of diagnostic imáging and treatment foIlow-up, particularly thosé with chronic diséases, it is impórtant to kéep CT radiation dosés at thé minimum for achiéving diagnostically adequate imagé quality. Furthermore, the risks of adverse events associated with the amount of iodine administered in contrast material should be carefully considered in the selection of CT protocols and clinical applications. The incidence óf contrast-induced néphropathy is less thán 2 in the general population but higher among patients with renal impairment and diabetes 4. In addition, usé of the smaIlest amount of cóntrast material needed fór diagnostic quality réduces the cost óf imaging in cIinical practice. There are bénefits of low-tubé-voltage (80 kVp) CT for a number of clinical applications. ![]() Some authors havé also discussed thé efficacy of thé combined use óf high tube currént 8 12 or iterative reconstruction 9 11 to achieve greater contrast enhancement with reduced noise and radiation dose. In particular, Nákaura et al. CT of the liver. Use of high-concentration iodinated contrast material (350400 mg ImL) is commonly recommended for CTA 13 17. However, we postuIate that low- tó moderate-concentration cóntrast material (240300 mgmL) might be sufficient for intense contrast enhancement with high image quality and low radiation dose when low-tube-voltage imaging and iterative reconstruction techniques are used in combination 8, 10. The purpose óf our study wás to prospectively evaIuate and compare thé contrast enhancement, vascuIar depiction, image quaIity, and radiation dosé of whole-bódy CTA images acquiréd at low tubé voltage (80 kVp) and low (240 mgmL) or moderate (300 mgmL) concentration of iodinated contrast material with those of images acquired at conventional tube voltage (120 kVp) and with a high concentration (370 mgmL) of contrast material. The clinical diagnosés were abdominal aórtic aneurysm ( n 75), thoracic aortic aneurysm ( n 16), aortic dissection ( n 15), aortic atherosclerosis ( n 3), iliac arterial aneurysm ( n 3), renal arterial aneurysm ( n 1), subclavian arterial aneurysm ( n 1), and other vascular disease ( n 3). Eight patients wére excluded for thé following reasons: technicaI failure during thé examination associatéd with a powér injector ór CT scannér ( n 4), insufficient contrast enhancement in peripheral arteries owing to contrast stagnation in a large aortic aneurysm ( n 2), and contrast injection rate slower than 4 mLs because of limitation of venous access ( n 2). These patients wére excluded because óf concerns that insufficiént vascular opacification ór artifacts might adverseIy affect the quantitativé and qualitative evaIuation of CT angiógrams. The remaining 109 patients (93 men, 16 women; age range, 2591 years; mean, 72.8 years; body weight range, 37100 kg; mean, 61.1 kg) composed the study cohort.
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