scholarly journals Clinical applications of digital angiography with the harmonization function in body interventional radiology

2020 ◽  
Vol 38 (10) ◽  
pp. 922-933
Author(s):  
Hidekatsu Tateishi ◽  
Kazunori Kuroki ◽  
Haruhiko Machida ◽  
Toshihiko Iwamoto ◽  
Toshiya Kariyasu ◽  
...  
Keyword(s):  
Interventional Radiology ◽  
Dynamic Range ◽  
Good Alternative ◽  
Motion Artifacts ◽  
Body Motion ◽  
Breath Holding ◽  
Lung Field ◽  
Anatomical Landmarks ◽  
Digital Angiography ◽  
Basic Facts

Abstract Digital subtraction angiography (DSA) is frequently applied in interventional radiology (IR). When DSA is not useful due to misregistration, digital angiography (DA) as an alternative option is used. In DA, the harmonization function (HF) works in real time by harmonizing the distribution of gray steps or reducing the dynamic range; thus, it can compress image gradations, decrease image contrast, and suppress halation artifacts. DA with HF as a good alternative to DSA is clinically advantageous in body IR for generating DSA-like images and simultaneously reducing various motion artifacts and misregistrations caused by patient body motion, poor breath-holding, bowel and ureter peristalsis, and cardiac pulsation as well as halation artifacts often stemming from the lung field. Free-breath DA with HF can improve body IR workflow and decrease the procedure time by reducing the risk of catheter dislocation and using background structures as anatomical landmarks, demonstrating reduced radiation exposure relative to DSA. Thus, HF should be more widely and effectively utilized for appropriate purposes in body IR. This article illustrates the basic facts and principles of HF in DA, and demonstrates clinical advantages and limitations of this function in body IR.

scholarly journals HeaDax: A simple pre-surgical procedure for localizing superficial brain lesions in resource-limited environments

2020 ◽  
Vol 11 ◽  
pp. 461
Author(s):  
Ali Akhaddar
Keyword(s):  
Ct Scan ◽  
Good Alternative ◽  
Anatomical Landmarks ◽  
Resonance Imaging ◽  
Electrical Wire ◽  
Orbital Roof ◽  
Skull Model ◽  
Resource Limited ◽  
Intracranial Lesions ◽  
Magnetic Resonance Imaging Guidance

Background: Intracranial convexity lesions are poorly defined by recognizable anatomical landmarks. Even in expert hands, exact localization of small subcortical lesion and its projection to the skull is sometimes unreliable and can cause potential surgical complications. In this report, a simple and handy technique for localizing superficial intracranial lesions on the scalp under computed tomography (CT)-scan guidance is described. Methods: This technique, HeaDax, is based on using extracranial landmarks. We constructed an isosceles square triangle with three pieces of copper electrical wire and placed it on the skin scalp. Then, we took a CT-scan but without the need of the classic head reference planes (e.g., orbitomeatal or along the orbital roof). Results: For the measurements, we need to have the intracranial lesion located on the CT slice with respect to the two landmarks which are the height and hypotenuse of the triangle. The promising preliminary results of HeaDax applied to a phantom skull model encourage us to use it successfully for our first patient presenting a right subcortial supramarginal retrorolandic cavernoma. Conclusion: HeaDax procedure is a good alternative for localizing superficial intracranial lesions on the skin scalp under CT-scan or magnetic resonance imaging guidance. It can be used as a substitute when stereotactic and neuronavigation systems are not easily available, especially in developing countries and in resource-limited environments. HeaDax has a true potential for further developments and applications in cranial surgery.

scholarly journals Contactless Simultaneous Breathing and Heart Rate Detections in Physical Activity Using IR-UWB Radars

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5503
Author(s):  
Xinyue Zhang ◽  
Xiuzhu Yang ◽  
Yi Ding ◽  
Yili Wang ◽  
Jialin Zhou ◽  
...  
Keyword(s):  
Physical Activity ◽  
Vital Signs ◽  
Motion Artifacts ◽  
Body Motion ◽  
Ultra Wideband ◽  
Body Movements ◽  
Range Resolution ◽  
Vital Signs Monitoring ◽  
Uwb Radar ◽  
Empirical Wavelet Transform

Vital signs monitoring in physical activity (PA) is of great significance in daily healthcare. Impulse Radio Ultra-WideBand (IR-UWB) radar provides a contactless vital signs detection approach with advantages in range resolution and penetration. Several researches have verified the feasibility of IR-UWB radar monitoring when the target keeps still. However, various body movements are induced by PA, which lead to severe signal distortion and interfere vital signs extraction. To address this challenge, a novel joint chest–abdomen cardiopulmonary signal estimation approach is proposed to detect breath and heartbeat simultaneously using IR-UWB radars. The movements of target chest and abdomen are detected by two IR-UWB radars, respectively. Considering the signal overlapping of vital signs and body motion artifacts, Empirical Wavelet Transform (EWT) is applied on received radar signals to remove clutter and mitigate movement interference. Moreover, improved EWT with frequency segmentation refinement is applied on each radar to decompose vital signals of target chest and abdomen to vital sign-related sub-signals, respectively. After that, based on the thoracoabdominal movement correlation, cross-correlation functions are calculated among chest and abdomen sub-signals to estimate breath and heartbeat. The experiments are conducted under three kinds of PA situations and two general body movements, the results of which indicate the effectiveness and superiority of the proposed approach.

Anatomical Coordinate Systems for Human Body Segments

1978 ◽  
Vol 22 (1) ◽  
pp. 676-679
Author(s):  
Arvind J. Padgaonkar ◽  
Shirley M. Lawson ◽  
Albert I. King
Keyword(s):  
Human Body ◽  
Body Motion ◽  
Anatomical Landmarks ◽  
Coordinate Systems ◽  
Body Segment ◽  
X Ray ◽  
Body Segments ◽  
Fixed Set ◽  
Injury Research ◽  
Impact Injury

An anatomically based coordinate system is a useful tool for standardizing the placement of instrumentation on segments of the human body or human surrogate. It is suggested that this system be based upon a fixed set of anatomical landmarks that are easily located by palpation and/or x-ray. A set of coordinate systems for the head, torso and extremities is proposed. Such systems will aid investigators in comparing data acquired at different laboratories involved in impact injury research. These systems can also be used for accurately locating the center of gravity of a body segment and for describing body motion in an impact environment.

scholarly journals A Stacked Back Side-Illuminated Voltage Domain Global Shutter CMOS Image Sensor with a 4.0 μm Multiple Gain Readout Pixel

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 486
Author(s):  
Ken Miyauchi ◽  
Kazuya Mori ◽  
Toshinori Otaka ◽  
Toshiyuki Isozaki ◽  
Naoto Yasuda ◽  
...  
Keyword(s):  
Dynamic Range ◽  
High Sensitivity ◽  
Cmos Image Sensor ◽  
Light Sensitivity ◽  
Image Sensor ◽  
Motion Artifacts ◽  
Oxide Semiconductor ◽  
Storage Capacitor ◽  
Cmos Process ◽  
Back Side

A backside-illuminated complementary metal-oxide-semiconductor (CMOS) image sensor with 4.0 μm voltage domain global shutter (GS) pixels has been fabricated in a 45 nm/65 nm stacked CMOS process as a proof-of-concept vehicle. The pixel components for the photon-to-voltage conversion are formed on the top substrate (the first layer). Each voltage signal from the first layer pixel is stored in the sample-and-hold capacitors on the bottom substrate (the second layer) via micro-bump interconnection to achieve a voltage domain GS function. The two sets of voltage domain storage capacitor per pixel enable a multiple gain readout to realize single exposure high dynamic range (SEHDR) in the GS operation. As a result, an 80dB SEHDR GS operation without rolling shutter distortions and motion artifacts has been achieved. Additionally, less than −140dB parasitic light sensitivity, small noise floor, high sensitivity and good angular response have been achieved.

Advanced Multiple Beam Equalization Radiography (AMBER) Combined with Computed Radiography

1993 ◽  
Vol 34 (5) ◽  
pp. 445-449 ◽  
Author(s):  
T. P. W. de Rooy ◽  
J. W. Oestmann ◽  
L. J. Schultze Kool ◽  
H. Vrooman ◽  
F. Buchmann
Keyword(s):  
Dynamic Range ◽  
Computed Radiography ◽  
Hard Copy ◽  
Average Dose ◽  
Lung Field ◽  
Multiple Beam ◽  
Digital Storage ◽  
Radiography System ◽  
Combined Use ◽  
Dose Levels

The combined use of AMBER (Advanced Multiple Beam Equalization Radiography) and a digital storage phosphor (SP) radiography system was evaluated for chest radiography in a pilot study with 4 patients. Four image modes with different dose levels were compared: the SP in combination with an AMBER equalized exposure (SP/AMBER) and 3 nonequalized exposures with dose levels corresponding to the respective calculated AMBER lung dose (SP/lung field dose), the calculated AMBER mediastinal dose (SP/mediastinal dose) and the calculated AMBER average dose (SP/average dose). All image modes were matched for Hurter and Driffield characteristics and subjectively rated according to visibility of details. The improved signal-to-noise (S/N) ratio of SP/AMBER resulted in a better visualization of structures in the mediastinum and the basal lung where SP/lung field dose scored lowest. For the central lung no quality differences were seen between techniques. The compressed dynamic range of the SP/AMBER images was more easily displayed on the hard-copy film. The combination of AMBER with SP radiography promises to overcome the dynamic range limitations of digital displays while, at moderate doses, giving better S/N and image quality than standard SP technique.

scholarly journals Designing a compact MRI motion phantom

2016 ◽  
Vol 2 (1) ◽  
pp. 471-474
Author(s):  
Max Schmiedel ◽  
Anita Moeller ◽  
Martin A. Koch ◽  
Alfred Mertins
Keyword(s):  
Motion Compensation ◽  
Rigid Motion ◽  
Small Animal ◽  
Ground Truth ◽  
Motion Artifacts ◽  
Body Motion ◽  
Retrospective Gating ◽  
Motion Phantom ◽  
Magnetic Resonance Imaging Mri ◽  
Small Animal Mri

AbstractEven today, dealing with motion artifacts in magnetic resonance imaging (MRI) is a challenging task. Image corruption due to spontaneous body motion complicates diagnosis. In this work, an MRI phantom for rigid motion is presented. It is used to generate motion-corrupted data, which can serve for evaluation of blind motion compensation algorithms. In contrast to commercially available MRI motion phantoms, the presented setup works on small animal MRI systems. Furthermore, retrospective gating is performed on the data, which can be used as a reference for novel motion compensation approaches. The motion of the signal source can be reconstructed using motor trigger signals and be utilized as the ground truth for motion estimation. The proposed setup results in motion corrected images. Moreover, the importance of preprocessing the MRI raw data, e.g. phase-drift correction, is demonstrated. The gained knowledge can be used to design an MRI phantom for elastic motion.

scholarly journals Attention Mechanism Based Semi-Supervised Multi-Gain Image Fusion

Symmetry ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 451
Author(s):  
Ming Fang ◽  
Xu Liang ◽  
Feiran Fu ◽  
Yansong Song ◽  
Zhen Shao
Keyword(s):  
Image Fusion ◽  
Network Structure ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Dynamic Imaging ◽  
Motion Artifacts ◽  
Attention Mechanism ◽  
Source Image ◽  
Fused Image ◽  
High Dynamic

High-dynamic range imaging technology is an effective method to improve the limitations of a camera’s dynamic range. However, most current high-dynamic imaging technologies are based on image fusion of multiple frames with different exposure levels. Such methods are prone to various phenomena, for example motion artifacts, detail loss and edge effects. In this paper, we combine a dual-channel camera that can output two different gain images simultaneously, a semi-supervised network structure based on an attention mechanism to fuse multiple gain images is proposed. The proposed network structure comprises encoding, fusion and decoding modules. First, the U-Net structure is employed in the encoding module to extract important detailed information in the source image to the maximum extent. Simultaneously, the SENet attention mechanism is employed in the encoding module to assign different weights to different feature channels and emphasis important features. Then, a feature map extracted from the encoding module is input to the decoding module for reconstruction after fusing by the fusion module to obtain a fused image. Experimental results indicate that the fused images obtained by the proposed method demonstrate clear details and high contrast. Compared with other methods, the proposed method improves fused image quality relative to several indicators.

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