On-site CT-FFR based on ML improves the performance of CTA by correctly reclassifying hemodynamically nonsignificant stenosis and performs equally well as CFD-based CT-FFR.

With use of a reduced-order algorithm, computation of the FFR from coronary CT angiography data can be performed locally, at a regular workstation. The diagnostic accuracy of coronary CT angiography-derived computational FFR for the detection of functionally important coronary artery disease (CAD) was good and was incremental to that of coronary CT angiography within a population with a high prevalence of CAD.

CT MPI and CTA FFR both identify functionally significant CAD, with comparable accuracy. Diagnostic performance can be improved by combining the techniques. A stepwise approach, reserving CT MPI for intermediate CTA FFR results, also improves diagnostic performance while omitting nearly one-half of the population from CT MPI examinations.

In our series of preselected patients, poor admission neurological grade, rebleeding episode(s), and lesions with a pearl-and-string structure were predictive of poor outcomes. Our findings indicate that patients with these characteristics may be candidates for aggressive attempts to prevent rebleeding during the acute stage. Patients without these characteristics may be good candidates for conservative treatment, especially those who survive the acute phase without rebleeding.

ontrast enhanced multislice spiral computed tomography (CE-MSCT) has been proposed as a means of evaluating coronary artery stenoses. [1][2][3] In just a few years, technological advances have progressively improved the temporal resolution. Recent studies showed that CE-MSCT allows for a noninvasive assessment of coronary artery disease (CAD) in a clinical setting. [4][5][6][7][8][9][10] In addition to coronary artery assessment, CE-MSCT can also provide information about myocardial perfusion. Koyama et al reported that CE-MSCT could describe acute myocardial infarction (AMI) as a perfusion defect after the injection of a bolus of contrast medium. 11 Their data showed myocardial viability and function after AMI.No attempt to detect myocardial ischemia using pharmacological stress MSCT has been reported previously. Adenosine triphosphate (ATP) is widely used as a coronary vasodilator to detect myocardial ischemia in the fields of magnetic resonance imaging, 12 nuclear imaging 13 and echocardiography. 14 We hypothesized that CE-MSCT can describe myocardial ischemia as a hypo-perfusion area (HPA) using the ATP provocation test. The present study was designed to: (i) to test our hypothesis; and (ii) to evaluate the potential of the ATP stress CE-MSCT in a clinical setting. Methods Study ProtocolThe study protocol necessitated that the enrolled patients underwent both ATP-provocation/non-provocation CE-MSCT and stress thallium-201 myocardial perfusion scintigraphy (MPS), and received conventional coronary angiography (CAG) as required. All patients gave their informed consent and the protocol was approved by the hospital's ethics committee.The entry criteria were as follows: (i) de novo effort or rest stable angina (documented ST-T change on electrcardiogram (ECG), or relieved by administration of nitroglycerin); (ii) no history of coronary angiography; and (iii) asymptomatic patients with a high probability of CAD (ie, multiple coronary risk factors) or abnormal findings in exercise ECG.The exclusion criteria included: (i) acute myocardial infarction (within 3 months); (ii) unstable angina (recent onset of angina within a month, severe and worsening clinical symptom); (iii) chronic atrial fibrillation; (iv) deteriorated renal function (serum creatinine >1.5 mg/dl); (v) pregnancy, hyperthyroidism or a known allergic reaction to Background The present study was designed to: (i) detect myocardial ischemia in contrast enhanced multislice spiral computed tomography (CE-MSCT) using adenosine triphosphate (ATP) pharmacological stress test; and (ii) evaluate the potential of ATP stress CE-MSCT in a clinical setting. Methods and ResultsTwelve patients underwent ATP stress CE-MSCT and stress thallium-201 myocardial perfusion scintigraphy (MPS) and 9 of the patients received conventional coronary angiography (CAG). Dual CE-MSCT scans were performed for stress and rest images, with and without intravenous infusion of ATP (0.16 mg·kg -1 ·min -1 ) at intervals of 20 min. Myocardial perfusion and coronary artery were visually eval...

The authors studied the venous drainage system and its impairment in relation to risk of hemorrhage in 108 cases of supratentorial arteriovenous malformation (AVM). The proportion of AVM's undergoing hemorrhage (hemorrhagic rate) was calculated in relation to: 1) the number of draining veins (one, two, or three or more); 2) the presence or absence of impairment in venous drainage (severe stenosis or occlusion in draining veins); and 3) the location of draining veins (deep venous drainage alone, superficial venous drainage alone, or a combination of the two). Statistical analysis demonstrated that AVM's with the following characteristics had a high risk of hemorrhage: 1) one draining vein (hemorrhagic rate 89% in 54 patients); 2) severely impaired venous drainage (hemorrhagic rate 94% in 18 patients); and 3) deep venous drainage alone (hemorrhagic rate 94% in 32 patients). The present study suggests that the venous drainage system of AVM's is significantly associated with the risk of hemorrhage of these lesions. Therefore, careful preoperative angiographic evaluation of the venous drainage system is mandatory for decision making in the management of patients with AVM's.

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SAFIRE noise reduction techniques significantly affected the CAC, which potentially alters perceived cardiovascular risk.