Noninvasive detection of coronary artery stenosis using 16-slice spiral CT: A comparison with selective X-ray coronary angiography

Abstract Context.—Homocysteine is emerging as a novel marker of atherothrombosis. Its role as an independent risk factor for cardiovascular disease is generally accepted. There is scanty data correlating homocysteine levels measured by immunoassay with cardiovascular disease. We previously validated a fluorescence polarization immunoassay for measuring homocysteine, which compared favorably with high performance liquid chromatography. Objective.—To determine if homocysteine levels measured by immunoassay correlate with extent of atherosclerotic burden, as represented by degree of coronary artery stenosis determined by coronary angiography. Design.—Fasting plasma samples were obtained from patients undergoing coronary angiography (N = 165). Homocysteine levels were measured by immunoassay and coronary artery stenosis was determined by coronary angiography. Results.—Median coronary artery stenosis for the 3 homocysteine subgroups, less than 1.35, 1.35 to 6.75, and greater than 6.75 mg/L (<10, 10–15, and >15 μmol/L), was 75%, 90%, and 99%, respectively (P = .01 for trend). Also, folate and vitamin B12 levels decreased with increasing homocysteine levels (P = .01 and .04, respectively, for trend). Spearman's correlation showed a significant association between homocysteine level and coronary artery stenosis (r = 0.20; P = .009). When men and women were examined separately, the correlation was significant only for women (r = 0.30; P = .01). Conclusion.—Homocysteine levels, as measured by immunoassay, show a positive correlation with cardiovascular disease in women. Thus, this is a valid measure of atherosclerotic burden and, therefore, a reliable addition to the established laboratory repertoire for the assessment of cardiovascular disease.

Download Full-text

Abstract 2806: Whole Heart Coronary Magnetic Resonance Angiography Using 32-Channel Cardiac Coils and High Parallel Imaging Factor

Circulation ◽

10.1161/circ.118.suppl_18.s_778-b ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Motonori Nagata ◽

Hajime Sakuma ◽

Nanaka Ishida ◽

Hiroshi Nakajima ◽

Masaki Ishida ◽

...

Keyword(s):

Coronary Artery ◽

Coronary Angiography ◽

Parallel Imaging ◽

Noninvasive Detection ◽

Acquisition Time ◽

Luminal Diameter ◽

X Ray ◽

Coronary Mra ◽

Imaging Time ◽

Whole Heart

PURPOSE Coronary MRA provides noninvasive detection of coronary artery disease (CAD) without administration of contrast medium or exposing the patient to radiation. However, use of coronary MRA in excluding patients with CAD has been limited due to lengthy imaging time. The purpose of this study was to reduce acquisition time of coronary MRA by using 32 channel cardiac coils and high parallel imaging factor, and to evaluate diagnostic performance of this method in detecting significant CAD. METHOD AND MATERIALS Sixty-two patients with suspected CAD were studied. Free-breathing coronary MRA encompassing the entire heart was acquired by using 32-channel coils and SENSE factor of 4. After monitoring motion of the coronary artery on cine MRI, MR angiograms were acquired during diastole in 46 patients (acquisition window 82±57ms) and during systole in 16 patients (50±19ms). Coronary MRA images were interpreted by 2 observers by employing a sliding SLAB MIP method. All patients underwent X-ray coronary angiography within 4 weeks from MRA, and significant CAD was defined as a luminal diameter reduction of 50% or more by QCA. All lesions with a reference diameter of 2mm or more on X-ray angiography were included when determining the accuracy of coronary MRA. RESULTS Acquisition of MRA was completed in all 62 patients, with the averaged imaging time of 6.1±2.6min. High SENSE factor achieved by 32-channel coils resulted in substantial reduction of imaging time by factor of >2, with the image quality score (4.6±0.2) at least equivalent to that by conventional 5-channel coils and SENSE factor of 2 (4.5±0.2). Significant CAD was observed on X-ray coronary angiography in 39 patients. MRA detected 33(85%) of 39 patients having CAD, with high specificity of 96%(22/23). All 16 patients with double- or triple-vessel diseases were detected by MRA. On a vessel based analysis, Whole-heart coronary MRA demonstrated sensitivity of 83%(49/59), specificity of 94%(119/127) and NPV of 92%(119/129). CONCLUSION Whole-heart coronary MRA with 1.5T MR imager and 32-chennel coils permits noninvasive detection of CAD with substantially reduced imaging time and high study success rate. High NPV (>90%) indicated the value of this approach in ruling out significant CAD.

Download Full-text

Abstract 5799: Fine-Cell Detector Computed Tomography with 0.3mm-Collimation Improves Quantitative Assessment of Coronary Artery Stenosis: Experimental Study with Coronary Phantom

Circulation ◽

10.1161/circ.118.suppl_18.s_105 ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Minoru yamada ◽

Masahiro Jinzaki ◽

Kozo Sato ◽

Yutaka Tanami ◽

Akihisa Ueno ◽

...

Keyword(s):

Computed Tomography ◽

Coronary Artery ◽

Focal Spot ◽

Coronary Artery Stenosis ◽

Hounsfield Unit ◽

Acrylonitrile Butadiene Styrene ◽

Artery Stenosis ◽

Data Sets ◽

Water Tank ◽

X Ray

The purpose of this study was to evaluate whether the prototype fine-cell detector computed tomography (FDCT) could improve smaller coronary artery stenosis measurement compared with 64-slice multidetector-row CT (MDCT). Method and Materials: We developed coronary phantoms of 2mm in diameter with 0%, 25%, 50%, 75% stenosis. Each stenotic part was made by Acrylonitrile-Butadiene-Styrene (ABS: 50 Hounsfield Unit (HU)) and lumen was filled with diluted iodine (380 HU). These coronary phantoms put into the water tank were scanned by both prototype FDCT and 64-slice MDCT. Configuration of FDCT was 32-row*0.3125mm detector collimation with 0.35mm smaller X-ray tube focal spot width, and that of 64-slice MDCT was 16-row*0.625mm detector collimation and 0.7mm X-ray focal spot. All axial images were reconstructed using Standard kernel with 96mm display field-of-view. Minimum lumen diameter and degree of stenosis in these data sets were automatically measured using the Vessel Analysis software (GE Healthcare). Results: Measured coronary lumen at 0%, 25%, 50%, 75% stenosis of 2mm-diameter phantom (corresponding to 2.0mm, 1.5mm, 1.0mm, 0.5mm) were 2.2mm, 1.8mm, 1.4mm, 0.7mm in FDCT, whereas those were 2.5mm, 2.0mm, 1.5mm, 1.4mm in 64-slice MDCT, respectively. Each degree of stenosis was calculated 21%, 38%, 69% in FDCT, while 20%, 38%, 44% in 64-slice MDCT. Measured value of 75% stenosis in FDCT was significantly improved compared with 64-slice MDCT. Conclusion: FDCT improves the accuracy of smaller coronary artery stenosis measurement compared with 64-slice MDCT. Superior spatial resolution of FDCT could be promising for more accurate assessment of the coronary artery stenosis.

Download Full-text