ABSTRACT
AIM: The purpose of this study was to investigate the feasibility of contrast-enhanced ultrasound (CEUS) in the evaluation of renal artery stenosis as compared with traditional techniques: echo color Doppler (ECD) investigation and selective angiography .CEUS is a technique based on the injection of an intravascular biocompatible tracer, namely an intravenous contrast galactose microparticle suspension containing microbubbles (Levovist), that has a similar rheology to that of red blood cells, allowing quantification of renal tissue perfusion. METHODS: A population of 120 hypertensive patients (82 men, mean age 55) with a systolic abdominal murmur and/or a diagnosis of poly-districtual atherosclerosis was studied by ECD and CEUS (Levovist). Selective angiography was performed in patients with renal artery stenosis demonstrated by one of the two ultrasonographic techniques. RESULTS: Forty of the 120 patients in the study population showed renal artery stenosis at one of the two ultrasound techniques: ECD identified renal artery stenosis in 33 cases and CEUS in 38. Instead, selective angiography had detected renal artery stenosis in 38 patients, the same with renal artery stenosis diagnosed by CEUS. Thus, CEUS sensitivity, specificity and accuracy were similar to those of angiography while six false negatives and two false positives were obtained with ECD. CONCLUSION: Our results suggest that this renal CEUS is a promising, new, non-invasive method for screening patients with suspected renal artery stenosis. This technique appears to be superior to traditional ECD flow imaging for diagnosing renal artery stenosis and so may be an important aid in cardiovascular diagnostics.
Subject(s)
Contrast Media , Polysaccharides , Renal Artery Obstruction/diagnostic imaging , Renal Artery/diagnostic imaging , Ultrasonography, Doppler, Color , Contrast Media/administration & dosage , False Negative Reactions , False Positive Reactions , Feasibility Studies , Female , Humans , Injections, Intravenous , Italy , Male , Middle Aged , Polysaccharides/administration & dosage , Predictive Value of Tests , Radiography , Sensitivity and SpecificityABSTRACT
BACKGROUND: Coronary flow is influenced by several determinants and may change according to external stimuli. In patients with dilated cardiomyopathy (DC), adaptive mechanisms could induce alterations in coronary flow, possibly related to oxygen consumption. METHODS: In 67 consecutive patients with DC (mean age 52.06+/-13.84, 52 male gender, left ventricle ejection fraction (LVEF) 29.49%+/-8.68) and normal coronary angiography findings, coronary flow in left anterior descending (LAD), right coronary artery (RC) and left circumflex (LCx) was reported as TIMI frame count (TFC). All patients underwent a cardiopulmonary test with VO2 peak and anaerobic threshold (AT) measurement, New York Heart Association (NYHA) class stratification, two-dimensional echocardiographic evaluation including LVEF and left ventricle end-diastolic diameter (LVEDD) assessment. All patients were receiving optimal medical treatment. RESULTS: In a multivariate analysis, a statistically significant correlation was found between VO2 peak and TFC (B 7.61, p<0.001, R2 0.61 for LAD; B 3.42, p<0.001, R2 0.33 for RC); an inverse correlation was found between AT and TFC (B -9.77, p<0.001, R2 0.61 for LAD; B -4.26, p<0.001, R2 0.33 for RC). CONCLUSIONS: Coronary flow is related to VO2 peak and AT in patients with DC, suggesting a "compensatory" mechanism.
