A device guidance method for organ motion compensation in MRI-guided therapy

Organ motion compensation in image-guided therapy is an active area of research. However, there has been little research on motion tracking and compensation in magnetic resonance imaging (MRI)-guided therapy. In this paper, we present a method to track a moving organ in MRI and control an active mechanical device for motion compensation. The method proposed is based on MRI navigator echo tracking enhanced by Kalman filtering for noise robustness. We also developed an extrapolation scheme to resolve any discrepancies between tracking and device control sampling rates. The algorithm was tested in a simulation study using a phantom and an active mechanical tool holder. We found that the method is feasible to use in a clinical MRI scanner with sufficient accuracy (0.36 mm to 1.51 mm depending on the range of phantom motion) and is robust to noise. The method proposed may be useful in MRI-guided targeted therapy, such as focused ultrasound therapy for a moving organ.     

Synergistic effect of baicalein,wogonin and oroxylin A mixture: multistep inhibition of the NF-κB signalling pathway contributes to an anti-inflammatory effect of Scutellaria root flavonoids

Journal of Natural Medicines - Scutellaria root, the root of Scutellaria baicalensis Georgi, is a crude drug used for inflammatory diseases. In our previous report, the combination of flavonoids...     

Usefulness of dobutamine stress echocardiography in a patient with aortic valve stenosis and left ventricular dysfunction: a case report

A 76-year-old man with previous antero-septal myocardial infarction and aorto-coronary bypass surgery developed exertional dyspnea. Echocardiography revealed diffuse left ventricular hypokinesis and aortic stenosis with a mean pressure gradient of 29 mmHg. Coronary angiography showed no significant lesions in the bypass grafts and total occlusions of the proximal left anterior descending artery and mid circumflex artery. Dobutamine stress echocardiography was performed to evaluate the severity of aortic stenosis and left ventricular functional reversibility. Administration of dobutamine increased the mean pressure gradients to 48 mmHg and increased the stroke volume by 28% without change in aortic valve area of about 0.5 cm2. We considered that our patient had severe aortic stenosis with contractile reserve. After aortic valve replacement, he improved with better left ventricular function.     

The latest wire technique for chronic total occlusion.

If patency is restored after chronic total occlusion (CTO), it can be maintained over the long term by implanting drug-eluting stents. The cause of unsuccessful percutaneous coronary intervention is usually failure of the wire to cross the site of CTO. The objective of this article is to describe the latest wire techniques for CTO. As for wire selection, CTO should generally be treated with hard-tipped spring wires, preferably Conquest Pro series (Asahi Intec). According to the penetrating strategy, the course of a blood vessel with CTO is established preoperatively and the wire is advanced based on the imaging data with minimum rotation (a torque of +/- 90 degrees or less). If the operator encounters divergence between the preoperative CTO image and the actual course of the coronary artery, the parallel wire technique should be used. With this method, a wire which enters the subintimal space is left there, and a second wire is inserted along it to find a new channel. When this technique is successful, the following findings are often noted: 1) the second wire crosses over the first one in the CTO; 2) the second wire shows more acute curve than the first wire; 3) the second wire penetrates the lesion from the outer curvature of the coronary artery and then is advanced along the same curvature of the vessel. Indeed, the second wire should be operated intentionally to achieve these findings so that the probability of success increases and the duration of the procedure is shortened.