Pharmacologic coronary vasodilation in conjunction with myocardial perfusion scintigraphy has become an alternative to dynamic exercise test for the diagnosis and risk stratification of coronary artery disease, especially in patients who are unable to perform adequate exercise. Dipyridamole and adenosine have been used for pharmacologic stress testing with myocardial perfusion imaging. Adenosine is a potent coronary vasodilator with rapid onset of action, short half-life, near maximal coronary vasodilation and less serious side effects. ST segment depression has been reported in about 7-15% of patients with coronary artery disease receiving dipyridamole in conjunction with myocardial perfusion imaging. The exact cause and clinical significance are not known. In order to evaluate the relationship between adenosine-induced ST segment depression during -MIBI myocardial perfusion scintigraphy and the severity of coronary artery disease, we performed -MIBI imaging after intravenous Infusion of adenosine In 120 patients with suspected coronary artery disease. Of the 120 patients, 28 also performed coronary angiography. There were 24 patients with ST segment depression during -MIBI scintigraphy and 96 patients without ST segment depression. Adenosine was infused Intravenously at a dose of 0.14mg/kg per minute lot 6minutes and -MIBI was injected at 3 minute. We then com-pared the hemodynamic changes, side effects, scintigraphic and angiographic findings. Heart rate increased beats/minute in the group with ST depression compared with beats/minute in the group without ST depression(p mmHg) than in the group without 57 depression(mmHg, p versus ) and during adenosine infusion( versus ) were significantly higher in the group with ST depression(p-MIBI images were abnormal in 23(96%) patients with ST segment depression and 66(69%) patients without ST segment depression(p versus , p versus , p-MIBI myocardial perfusion scintigraphy with Intravenous adenosine is related to the severity of coronary artery disease.
Pharmacologic coronary vasodilation in conjunction with myocardial scintigraphy has become an accepted alternative to dynamic exercise testing for the diagnosis of coronary artery disease. Although dipyridamole has traditionally been used for this purpose, it causes frequent side effect, which at times can be life-threatening. Moreover, dipyridamole dose not elicit maximal coronary vasodilation in a substantial number of patients receiving the usual i.v. dose. Adenosine is an endogenously produced compound that has significant effects as a coronary vasodilator and rapid onset action and extremely short half-life ( myocardial scintigraphy were evaluated and comparison with exercise was performed. Twenty-eight subjects underwent imaging after adenosine infusion and exercise imaging. Adenosine was infused intravenously at a dose of 0.14mg/kg/body weight per minute for 6 min and MIBI was injected at 3 minute. Adenosine caused an incerease in heart rate ( at baseline versus beats/min at peak effect, p 1 mm) and second degree AV block in electrocardiography occured in 11% of the patients, respectively. The overall sensitivity and specificity for individual coronary stenoses in 16 patients underwent coronary angiography were 88% and 95%, respectively. The agreement ratio of segmental perfusion between adenosine and exercise images was 92% (Kappa index=0.82). In conclusion, myocardial perfusion scintigraphy with intravenous adenosine is a feasible, safe and highly accurate noninvasive technique for the detection of coronary artery disease and results are at least comparable with those of exercise scintigraphy.
The purpose of our study was to assess the extrarenal length of renal arterial branches and tumour-feeding arteries on multidetector CT (MDCT) angiography, in addition to the perihilar branching patterns, with relevance to segmental artery clamping.MDCT angiograms of 64 patients with renal masses <4 cm were retrospectively reviewed by 2 radiologists. The perihilar branching patterns of the single main renal artery were assessed according to the number of pre-segmental and segmental arteries. The extrarenal lengths of segmental plus pre-segmental arteries and the tumour-feeding arteries, measured on volume-rendered images, were compared according to the vascular segmentation and the tumour location, respectively.In the 116 kidneys, 1 pre-segmental plus 5 segmental arteries (n=48) was the most common branching pattern. The mean extrarenal length of the inferior segmental plus pre-segmental arteries (33.05 mm) and the posterior segmental plus pre-segmental arteries (32.30 mm) was longer than any of the other segmental plus pre-segmental arteries (apical, 23.87 mm; superior, 26.80 mm; middle, 29.23 mm) (p<0.05). The mean extrarenal length of the lower pole tumour-feeding arteries (35.94 mm) was longer than those of the upper and mid-pole tumour-feeding arteries (24.95 mm, 29.62 mm), with significant difference between the lower and the upper pole tumour-feeding arteries (p<0.05).Tumours in the lower pole, supplied by the inferior or posterior segmental artery, may be more amenable to segmental artery clamping.MDCT angiography with volume rendering can demonstrate the extrarenal length of tumour-feeding arteries and may help in determining the accessibility for segmental artery clamping.
We report an elderly patient in whom a thrombus in the distal left pulmonary artery was shown by transesophageal echocardiography to extend and produce obstruction of the descending lobar branches as well as dilatation of the left bronchial artery.
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