Mechanisms of ergonovine-induced hyperconstriction of coronary artery after x-ray irradiation in pigs

1995 ◽  
Vol 90 (2) ◽  
pp. 167-175 ◽  
Author(s):  
S. Egashira ◽  
W. Mitsuoka ◽  
H. Tagawa ◽  
T. Kuga ◽  
H. Tomoike ◽  
...  
Keyword(s):  
Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Shingo Kato ◽  
Hajime Sakuma ◽  
Nanaka Ishida ◽  
Masaki Ishida ◽  
Motonori Nagata ◽  
...  

Background: CT coronary angiography is widely used to assess the presence of significant coronary artery disease (CAD). However, CT approach is associated with low but nonnegligible cancer risk. The purpose of this prospective multicenter study was to evaluate the diagnostic performance of coronary magnetic resonance angiography (MRA) in the ability to identify patients with significant CAD compared with coronary angiography. Materials and Methods: The subjects were recruited from 7 institutions. Free breathing coronary MR angiograms covering the entire coronary artery tree were obtained in 138 patients who were suspicious of CAD. Non-contrast enhanced images were acquired with a commercial 1.5T MR imager and five-element cardiac coils after sublingual administration of isosorbide dinitrate. Conventional X-ray coronary angiography was performed within 4 weeks after coronary MRA. MR and X-ray angiograms were sent to a core laboratory for blinded interpretation. Coronary MR angiograms were evaluated by two experienced investigators by using sliding partial MIP reconstruction. Quantitative X-ray coronary angiography analysis was performed with significant CAD defined as luminal narrowing of at least 50% of the diameter. Results: The mean imaging time of coronary MRA was 9.5 ± 4.9 minutes. The prevalence of significant disease on X-ray angiography was 45% (62/138). On a vessel-based analysis, the area under receiver operating characteristic (ROC) curve for the MRA compared with X-ray angiography was 0.90 (95% CI; 0.86 to 0.93). On a patient based analysis, the ROC area was 0.88 (95% CI; 0.81– 0.93). The sensitivity, specificity, positive and negative predictive values of coronary MRA by vessel analysis were 78% (95% CI; 68 – 86%), 86% (82–90%), 60% (51– 69%), 94% (90–96%). These values by patient analysis were 87% (95% CI; 76–94%), 71% (59 – 81%), 71% (59 – 81%), 87% (76–94%). Conclusions: In the current multicenter study using commercial 1.5T MR imagers and sliding partial MIP reconstruction, the diagnostic accuracy of coronary MRA compared to quantitative coronary angiography is good, reflected by an ROC area of 0.88 on patient-based analysis. High negative predictive value indicates that coronary MRA can be used for screening CAD.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Motonori Nagata ◽  
Hajime Sakuma ◽  
Nanaka Ishida ◽  
Hiroshi Nakajima ◽  
Masaki Ishida ◽  
...  

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.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Minoru yamada ◽  
Masahiro Jinzaki ◽  
Kozo Sato ◽  
Yutaka Tanami ◽  
Akihisa Ueno ◽  
...  

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.


2017 ◽  
Vol 849 ◽  
pp. 012002
Author(s):  
Sofiya Matviykiv ◽  
Marzia Buscema ◽  
Hans Deyhle ◽  
Thomas Pfohl ◽  
Andreas Zumbuehl ◽  
...  

2011 ◽  
Vol 7 (04) ◽  
pp. 275-279 ◽  
Author(s):  
Eiji Tamiya ◽  
Yoshiyuki Hada ◽  
Takeshi Ando ◽  
Yoshihiro Murota ◽  
Nobuhiko Ito ◽  
...  

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