다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

The analysis of medical images has been woven into the fabric of the pattern analysis and machine intelligence (PAMI) community since the earliest days of these Transactions. Initially, the efforts in this area were seen as applying pattern analysis and computer vision techniques to another interesting dataset. However, over the last two to three decades, the unique nature of the problems presented within this area of study have led to the development of a new discipline in its own right. Examples of these include: the types of image information that are acquired, the fully three-dimensional image data, the nonrigid nature of object motion and deformation, and the statistical variation of both the underlying normal and abnormal ground truth. In this paper, we look at progress in the field over the last 20 years and suggest some of the challenges that remain for the years to come.

https://hal.inria.fr/inria-00615100/document

Medical image analysis: progress over two decades and the challenges ahead

http://ee.sharif.edu/~miap/Files/A%20Survey%20of%20Medical%20Image%20Registration.pdf

A survey of medical image registration.

An image guided catheter navigation system for navigating a region of a patient includes an imaging device, a tracking device, a controller, and a display. The imaging device generates images of the region of the patient. The tracking device tracks the location of the catheter in the region of the patient. The controller superimposes an icon representing the catheter onto the images generated from the imaging device based upon the location of the catheter. The display displays the image of the region with the catheter superimposed onto the image at the current location of the catheter.

Navigation system for cardiac therapies

The complexity, diversity, and heterogeneity of tumors seriously undermine the therapeutic potential of treatment. Therefore, the current trend in clinical research has gradually shifted from a focus on monotherapy to combination therapy for enhanced treatment efficacy. More importantly, the cooperative enhancement interactions between several types of monotherapy contribute to the naissance of multimodal synergistic therapy, which results in remarkable superadditive (namely “1 + 1 > 2”) effects, stronger than any single therapy or their theoretical combination. In this review, state-of-the-art studies concerning recent advances in nanotechnology-mediated multimodal synergistic therapy will be systematically discussed, with an emphasis on the construction of multifunctional nanomaterials for realizing bimodal and trimodal synergistic therapy as well as the intensive exploration of the underlying synergistic mechanisms for explaining the significant improvements in synergistic therapeutic outcome. Furtherm...

Nanotechnology for Multimodal Synergistic Cancer Therapy

Photoacoustic (PA) imaging aims for the reconstruction of acoustic sources that originate in pulsed light absorption. While the speed of sound (SOS) in biological tissue is heterogeneous, standard reconstruction algorithms usually assume a constant SOS. This results in deformations of the reconstructed sources, which are referred to as aberration and can have a severe impact on the spatial resolution. If the SOS is known, aberrations can be compensated during the reconstruction at the expense of an increasing computational effort. Algorithms that account for heterogeneous SOS usually compute individual delays for each reconstructed pixel or perform an entire wave field simulation. In this contribution, we present an alternative approach by introducing a PA backpropagation based on a paraxial approximation of the wave equation that can be computed with almost the computational efficiency of a standard frequency domain reconstruction. The method accounts for refraction and neglects unwanted back-reflections during the backpropagation process. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 731771, Photonics Private Public Partnership, and is supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number 16.0160. Dominic Depke is supported by the Graduate School of the Cells-in-Motion Cluster of Excellence (EXC 1003 — CiM), University of Munster, Germany.

Aberration correction in photoacoustic imaging using paraxial backpropagation

In the diagnosis and early detection of prostatic cancer transrectal ultrasound is the most important imaging modality. However, the sensitivity and specificity of the standard sonographic methods are still not satisfactory. In this paper we describe a method which provides the clinician with additional information in form of color-coded tissue characterization images based on an estimation of the tissue malignancy from spectral and texture parameters.

Color-Coded Tissue Characterization Images of the Prostate

Purpose

To evaluate the use of the recently proposed ultrafast B1+ mapping approach DREAM (Dual Refocusing Echo Acquisition Mode) for a refinement of patient adaptive radiofrequency (RF) shimming



Materials and Methods

Volumetric DREAM B1+ calibration scans centered in the upper abdomen were acquired in 20 patients and three volunteers with written informed consent at a clinical dual source 3 Tesla (T) MR system Based on these data, RF transmit settings were optimized by central-slice based RF-shimming (CS-RF shim) and by a refined, multi-slice adaptive approach (MS-RF shim) Simulations were performed to compare flip angle accuracy and B1+ homogeneity (cv = stddev/mean) achieved by CS-RF shim versus MS-RF shim for transversal and coronal slices, and for volume shimming on the spine



Results

By MS-RF shim, mean deviation from nominal flip angle was reduced to less than 11% in all slices, all targets, and all subjects Relative improvements in B1+ cv (MS-RF shim versus CS-RF) were up to 14%/39%/47% in transversal slices/coronal slices/ spine area



Conclusion

Volumetric information about B1+ can be used to further improve the accuracy and homogeneity of the B1+ field yielding higher diagnostic confidence, and will also be of value for various quantitative methods which are sensitive to flip angle imperfections J Magn Reson Imaging 2014;40:857–863 © 2013 Wiley Periodicals, Inc

https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmri.24438

Ultrafast volumetric B1 (+) mapping for improved radiofrequency shimming in 3 tesla body MRI.

The driving of contrast microbubbles towards a boundary by means of primary radiation forces has been of interest for ultrasound-assisted drug delivery. Secondary radiation forces, resulting from oscillating microbubbles under ultrasound insonification, may cause the mutual attraction and subsequent coalescence of contrast microbubbles. This phenomenon has been less studied. Microbubbles with a negligible shell can be forced to translate towards each other at relatively low mechanical indices (MI). Thick-shelled microbubbles would require a higher MI to be moved. However, at high MI, microbubble disruption is expected. We investigated if thick-shelled contrast agent microbubbles can be forced to cluster at high-MI. The thick-shelled contrast agent M1639, inserted through a cellulose capillary, was subjected to 3 MHz, high-MI pulsed ultrasound from a commercial ultrasound machine, and synchronously captured through a high numerical aperture microscope. The agent showed the ultrasound-induced formation of bubble clusters, and the translation thereof towards the capillary boundary. Hence, forced translation and clustering of thick-shelled contrast microbubbles is feasible. The phase difference between the excursion of the oscillating bubble and the incident sound field was computed for free and encapsulated bubbles. There is a transition in phase difference for encapsulated bubbles, owing to the friction of the shell. Therefore, approach velocities of encapsulated bubbles may not be comparable to those of free gas bubbles.

/pdf/mutual-attraction-of-oscillating-microbubbles-4x4namiktq.pdf

Mutual Attraction of Oscillating Microbubbles

Ultrasound super-resolution imaging of microvessels and quantifying flow velocities have been proposed lately by several authors [1,2,3]. The standard approach is tracking microbubbles (MB) by searching for the nearest neighbor (NN) detection in consecutive frames. In [3] a Markov chain Monte Carlo data association (MCMCDA) algorithm was implemented to handle more complex vessel morphologies and/or higher bubble concentrations. Here, we investigate the performance of the algorithms in random vessel trees with known ground truth which simulate typical measurement conditions when imaging tumors in vivo. By this, we evaluate the quality of vessel reconstruction, the accuracy of velocity estimates and the influence of microbubble concentration. We demonstrate advantages of the MCMCDA in estimation accuracy of tracks and velocities in more complex vessel morphologies as they are expected in tumor microvasculature.

Georg Schmitz

Papers

Aberration correction in photoacoustic imaging using paraxial backpropagation

Color-Coded Tissue Characterization Images of the Prostate

Ultrafast volumetric B1 (+) mapping for improved radiofrequency shimming in 3 tesla body MRI.

Mutual Attraction of Oscillating Microbubbles

Evaluation of bubble tracking algorithms for super-resolution imaging of microvessels