[Visualization of laryngopharynx during swallowing of negative contrast media (air) with cine mode 64-row MDCT].

Science.gov (United States)

Fudeya, Taku; Otake, Shoichiro; Watabe, Hirotaka; Mitsuoka, Takashi; Yoshikawa, Akitoshi

2010-05-20

Video fluoroscopic examination of swallowing generally needs a contrast media such as a barium sulfate. Since the examination is usually performed in patients with dysphasia, there is a risk of aspiration. We tried to visualize the laryngopharynx during swallowing of negative contrast media (air) with 64-row multi-detector computed tomography (64-MDCT). Cine mode 64-MDCT was performed to visualize the laryngopharynx in 4 healthy volunteers during swallowing of negative contrast media (air). The data were converted to three-dimensional (3D) images of 2 conditions (air and bone) and sagittal images of the soft tissue condition at a workstation. These images were sent to a personal computer and modeled to 3D cine images with Digital Imaging and Communication in Medicine (DICOM) Viewer and Quick Time Player. 3D cine images demonstrated movements of the epiglottis, vallecula, piriform sinus, tongue, pharyngeal wall, hyoid bone and thyroid cartilage.

The Role of Cine Flow Magnetic Resonance Imaging in Patients with Chiari 0 Malformation.

Science.gov (United States)

Ozsoy, Kerem Mazhar; Oktay, Kadir; Cetinalp, Nuri Eralp; Gezercan, Yurdal; Erman, Tahsin

2018-01-01

To define the role of phase-contrast cine magnetic resonance imaging (MRI) in deciding the therapeutic strategy and underlying pathophysiology resulting in syrinx formation in patients with Chiari type 0 malformation. Seven patients who were admitted to our clinic with the diagnosis of Chiari 0 malformation from January 2005 to July 2016 were enrolled in the study. All patients underwent a detailed preoperative neurological examination. Entire neuroaxis MRI and phase-contrast cine MRI were obtained preoperatively and postoperatively. Seven patients (5 female and 2 male) with Chiari type 0 malformation fulfilled the inclusion criteria. All of the patients had absent cine flow at the craniovertebral junction except two patients. These five patients underwent surgical interventions; suboccipital decompression and duraplasty. All of them showed both clinical and radiological improvement in the postoperative period. Cine flow MRI appears to be a useful tool in the management of patients with Chiari 0 malformation. There was a good correlation between the clinical presentation and cine flow preoperatively, and between clinical improvement and cine flow in the postoperative period.

Differentiation of recently infarcted myocardium from chronic myocardial scar: the value of contrast-enhanced SSFP-based cine MR imaging

International Nuclear Information System (INIS)

Kim, Kyoung Ah; Seo, Joon Beom; Do, Kyoung Hyun; Heo, Jeong Nam; Lee, Young Kyung; Song, Jae Woo; Lee, Jin Seong; Song, Koun Sik; Lim, Tae Hwan

2006-01-01

The purpose of this study is to demonstrate whether the signal intensity (SI) of myocardial infarction (MI) on contrast enhanced (CE)-cine MRI is useful for differentiating recently infarcted myocardium from chronic scar. This study included 24 patients with acute MI (36-84) years, mean age: 57) and 19 patients with chronic MI (44-80) years, mean age: 64). The diagnosis of acute MI was based on the presence of typical symptoms, i.e. elevation of the cardiac enzymes and the absence of any remote infarction history. The diagnosis of chronic MI was based on a history of MI or coronary artery disease of more than one month duration and on the absence of any recent MI within the previous six months. Retrospectively, the ECG-gated breath-hold cine imaging was performed in the short axis plane using a segmented, balanced, turbo-field, echo-pulse sequence two minutes after the administration of Gd-DTPA at a dose of 0.2 mmol/kg body weight. Delayed contrast-enhanced MRI (DCE MRI) in the same plane was performed 10 to 15 minutes after contrast administration, and this was served as the gold standard of reference. The SI of the infarcted myocardium on the CE-cine MRI was compared with that of the normal myocardium on the same image. The area of abnormal SI on the CE-cine MRI was compared with the area of hyper enhancement on the DCE MRI. The area of high SI on the CE-cine MRI was detected in 23 of 24 patients with acute MI (10 with homogenous high SI, 13 high SI with subendocardial low SI, and one with iso SI). The area of high SI on the CE- cine MRI was larger than that seen on the DCE MRI (ρ < 0.05). In contrast, the areas of chronic MI were seen as iso-SI with thin subendocardial low SI on the CE-cine MR in all the chronic MI patients. The presence of high SI on both the CE-cine MRI and the DCE MRI is more sensitive (95.8%) for determining the age of a MI than the presence of myocardial thinning (66.7%). The study showed the different SI patterns between recently

Cine Magnetic Resonance Imaging of the Small Bowel: Comparison of Different Oral Contrast Media

International Nuclear Information System (INIS)

Asbach, P.; Breitwieser, C.; Diederichs, G.; Eisele, S.; Kivelitz, D.; Taupitz, M.; Zeitz, M.; Hamm, B.; Klessen, C.

2006-01-01

Purpose: To evaluate several substances regarding small bowel distension and contrast on balanced steady-state free precession (bSSFP) cine magnetic resonance (MR) images. Material and Methods: Luminal contrast was evaluated in 24 volunteers after oral application of two different contrast agent groups leading to either bright lumen (pineapple, blueberry juice) or dark lumen (tap water, orange juice) on T1-weighted images. Bowel distension was evaluated in 30 patients ingesting either methylcellulose or mannitol solution for limiting intestinal absorption. Fifteen patients with duodeno-jejunal intubation served as the control. Quantitative evaluation included measurement of luminal signal intensities and diameters of four bowel segments, qualitative evaluation assessed luminal contrast and distension on a five-point scale. Results: Quantitative and qualitative evaluation of the four contrast agents revealed no significant differences regarding luminal contrast on bSSFP images. Quantitative evaluation revealed significantly lower (P<0.05) small bowel distension for three out of four segments (qualitative evaluation: two out of four segments) for methylcellulose in comparison to the control. Mannitol was found to be equal to the control. Conclusion: Oral ingestion of tap water or orange juice in combination with mannitol is recommended for cine MR imaging of the small bowel regarding luminal contrast and small bowel distension on bSSFP sequences

Cine Magnetic Resonance Imaging of the Small Bowel: Comparison of Different Oral Contrast Media

Energy Technology Data Exchange (ETDEWEB)

Asbach, P.; Breitwieser, C.; Diederichs, G.; Eisele, S.; Kivelitz, D.; Taupitz, M.; Zeitz, M.; Hamm, B.; Klessen, C. [Charite - Universitatsmedizin Berlin, Charite Campus Mitte, Berlin (Germany). Dept. of Radiology

2006-11-15

Purpose: To evaluate several substances regarding small bowel distension and contrast on balanced steady-state free precession (bSSFP) cine magnetic resonance (MR) images. Material and Methods: Luminal contrast was evaluated in 24 volunteers after oral application of two different contrast agent groups leading to either bright lumen (pineapple, blueberry juice) or dark lumen (tap water, orange juice) on T1-weighted images. Bowel distension was evaluated in 30 patients ingesting either methylcellulose or mannitol solution for limiting intestinal absorption. Fifteen patients with duodeno-jejunal intubation served as the control. Quantitative evaluation included measurement of luminal signal intensities and diameters of four bowel segments, qualitative evaluation assessed luminal contrast and distension on a five-point scale. Results: Quantitative and qualitative evaluation of the four contrast agents revealed no significant differences regarding luminal contrast on bSSFP images. Quantitative evaluation revealed significantly lower (P<0.05) small bowel distension for three out of four segments (qualitative evaluation: two out of four segments) for methylcellulose in comparison to the control. Mannitol was found to be equal to the control. Conclusion: Oral ingestion of tap water or orange juice in combination with mannitol is recommended for cine MR imaging of the small bowel regarding luminal contrast and small bowel distension on bSSFP sequences.

Measurement of renal blood flow by phase-contrast magnetic resonance imaging during septic acute kidney injury: a pilot investigation.

Science.gov (United States)

Prowle, John R; Molan, Maurice P; Hornsey, Emma; Bellomo, Rinaldo

2012-06-01

In septic patients, decreased renal perfusion is considered to play a major role in the pathogenesis of acute kidney injury. However, the accurate measurement of renal blood flow in such patients is problematic and invasive. We sought to overcome such obstacles by measuring renal blood flow in septic patients with acute kidney injury using cine phase-contrast magnetic resonance imaging. Pilot observational study. University-affiliated general adult intensive care unit. Ten adult patients with established septic acute kidney injury and 11 normal volunteers. Cine phase-contrast magnetic resonance imaging measurement of renal blood flow and cardiac output. The median age of the study patients was 62.5 yrs and eight were male. At the time of magnetic resonance imaging, eight patients were mechanically ventilated, nine were on continuous hemofiltration, and five required vasopressors. Cine phase-contrast magnetic resonance imaging examinations were carried out without complication. Median renal blood flow was 482 mL/min (range 335-1137) in septic acute kidney injury and 1260 mL/min (range 791-1750) in healthy controls (p = .003). Renal blood flow indexed to body surface area was 244 mL/min/m2 (range 165-662) in septic acute kidney injury and 525 mL/min/m2 (range 438-869) in controls (p = .004). In patients with septic acute kidney injury, median cardiac index was 3.5 L/min/m2 (range 1.6-8.7), and median renal fraction of cardiac output was only 7.1% (range 4.4-10.8). There was no rank correlation between renal blood flow index and creatinine clearance in patients with septic acute kidney injury (r = .26, p = .45). Cine phase-contrast magnetic resonance imaging can be used to noninvasively and safely assess renal perfusion during critical illness in man. Near-simultaneous accurate measurement of cardiac output enables organ blood flow to be assessed in the context of the global circulation. Renal blood flow seems consistently reduced as a fraction of cardiac output in

Visualization and quantitative analysis of the CSF pulsatile flow with cine MR phase imaging

International Nuclear Information System (INIS)

Katayama, Shinji; Itoh, Takahiko; Kinugasa, Kazushi; Asari, Shoji; Nishimoto, Akira; Tsuchida, Shohei; Ono, Atsushi; Ikezaki, Yoshikazu; Yoshitome, Eiji.

1991-01-01

The visualization and the quantitative analysis of the CSF pulsatile flow were performed on ten healthy volunteers with cine MR phase imaging, a combination of the phase-contrast technique and the cardiac-gating technique. The velocities appropriate for the visualization and the quantitative analysis of the CSF pulsatile flow were from 6.0 cm/sec to 15.0 cm/sec. The applicability of this method for the quantitative analysis was proven with a steady-flow phantom. Phase images clearly demonstrated a to-and-fro motion of the CSF flow in the anterior subarachnoid space and in the posterior subarachnoid space. The flow pattern of CSF on healthy volunteers depends on the cardiac cycle. In the anterior subarachnoid space, the cephalic CSF flow continued until a 70-msec delay after the R-wave of the ECG and then reversed to caudal. At 130-190 msec, the caudal CSF flow reached its maximum velocity; thereafter it reversed again to cephalic. The same turn appeared following the phase, but then the amplitude decreased. The cephalic peaked at 370-430 msec, while the caudal peaked at 490-550 msec. The flow pattern of the CSF flow in the posterior subarachnoid space was almost identical to that in the anterior subarachnoid space. Cine MR phase imaging is thus useful for the visualization and the quantitative analysis of the CSF pulsative flow. (author)

Usefulness of breath-hold cardiac cine MR imaging with a middle field MRI system

Energy Technology Data Exchange (ETDEWEB)

Matsumura, Kentaro; Sato, Kiyoto; Aono, Masaki; Inoshita, Kenji; Utsumi, Naoko [Kagawa Inoshita Hospital, Ohnohara (Japan)

1999-07-01

To assess the accuracy of contrast-enhanced, single breath-hold cine MR imaging in calculating left ventricular volume and ejection fraction, we compared MR measurements with those obtained by using cine ventriculography in 60 patients. Fast cine MR images were acquired with a middle field MR system (0.5 T). A breath-hold single slice multi-phase fast gradient-echo (Fast Card) sequence was used to obtain fast cine MR images with the following parameters; TR of 16 ms, TE of 3 ms, flip angle of 30 degree, matrix elements of 256 x 128, view per segment of 6, field of view of 350 x 260 mm and one excitation. Left ventricular end-diastolic volume and ejection fraction obtained with contrast-enhanced Fast Card correlated well with those obtained with cine ventriculography (end-diastolic volume, y=1.00x+14.0, r=0.904, p<0.001; ejection fraction, y=0.961x+2.8, r=0.936, p<0.001). Our results show that contrast enhanced breath-hold cardiac cine MR imaging on horizontal long-axis view using a middle field MR system is an accurate method for evaluating left ventricular volume and ejection fraction. (author)

Cardiovascular cine imaging and flow evaluation using Fast Interrupted Steady-State (FISS) magnetic resonance.

Science.gov (United States)

Edelman, Robert R; Serhal, Ali; Pursnani, Amit; Pang, Jianing; Koktzoglou, Ioannis

2018-02-19

Existing cine imaging techniques rely on balanced steady-state free precession (bSSFP) or spoiled gradient-echo readouts, each of which has limitations. For instance, with bSSFP, artifacts occur from rapid through-plane flow and off-resonance effects. We hypothesized that a prototype cine technique, radial fast interrupted steady-state (FISS), could overcome these limitations. The technique was compared with standard cine bSSFP for cardiac function, coronary artery conspicuity, and aortic valve morphology. Given its advantageous properties, we further hypothesized that the cine FISS technique, in combination with arterial spin labeling (ASL), could provide an alternative to phase contrast for visualizing in-plane flow patterns within the aorta and branch vessels. The study was IRB-approved and subjects provided consent. Breath-hold cine FISS and bSSFP were acquired using similar imaging parameters. There was no significant difference in biplane left ventricular ejection fraction or cardiac image quality between the two techniques. Compared with cine bSSFP, cine FISS demonstrated a marked decrease in fat signal which improved conspicuity of the coronary arteries, while suppression of through-plane flow artifact on thin-slice cine FISS images improved visualization of the aortic valve. Banding artifacts in the subcutaneous tissues were reduced. In healthy subjects, dynamic flow patterns were well visualized in the aorta, coronary and renal arteries using cine FISS ASL, even when the slice was substantially thicker than the vessel diameter. Cine FISS demonstrates several benefits for cardiovascular imaging compared with cine bSSFP, including better suppression of fat signal and reduced artifacts from through-plane flow and off-resonance effects. The main drawback is a slight (~ 20%) decrease in temporal resolution. In addition, preliminary results suggest that cine FISS ASL provides a potential alternative to phase contrast techniques for in-plane flow

Cine MRI of dissecting aneurysm

International Nuclear Information System (INIS)

Takaki, Hajime

1991-01-01

Cine MRI was performed in 25 cases of aortic dissection and comparative study among cine MRI, spin-echo static MRI, contrast-enhanced CT and intravenous digital subtraction angiography (IVDSA) was made. Cine MRI accurately detected aortic dissection. It was most accurate among various diagnostic methods in demonstration of entry site of dissection. Take-off of renal artery and its relation to true and false channels was also accurately demonstrated by cine MRI. The above results suggest that cine MRI can be an important diagnostic modality with almost equal diagnostic quality to those of conventional angiography. However, further technical improvement to shorten the imaging time seems necessary to replace angiography. (author)

Self-gated CINE MRI for combined contrast-enhanced imaging and wall-stiffness measurements of murine aortic atherosclerotic lesions

NARCIS (Netherlands)

den Adel, Brigit; van der Graaf, Linda M.; Strijkers, Gustav J.; Lamb, Hildo J.; Poelmann, Robert E.; van der Weerd, Louise

2013-01-01

High-resolution contrast-enhanced imaging of the murine atherosclerotic vessel wall is difficult due to unpredictable flow artifacts, motion of the thin artery wall and problems with flow suppression in the presence of a circulating contrast agent. We applied a 2D-FLASH retrospective-gated CINE MRI

In-vivo quantification of wall motion in cerebral aneurysms from 2D cine phase contrast magnetic resonance images

Energy Technology Data Exchange (ETDEWEB)

Karmonik, C. [The Methodist Hospital Research Inst., Houston (United States); Diaz, O.; Klucznik, R. [The Methodist Hospital, Houston (United States); Grossman, R. [The Methodist Hospital, Houston (United States). Neurosurgery

2010-02-15

Purpose: The quantification of wall motion in cerebral aneurysms is of interest for the assessment of aneurysmal rupture risk, for providing boundary conditions for computational simulations and as a validation tool for theoretical models. Materials and Methods: 2D cine phase contrast magnetic resonance imaging (2D pcMRI) in combination with quantitative magnetic resonance angiography (QMRA) was evaluated for measuring wall motion in 7 intracranial aneurysms. In each aneurysm, 2 (in one case 3) cross sections, oriented approximately perpendicular to each other, were measured. Results: The maximum aneurysmal wall distention ranged from 0.16 mm to 1.6 mm (mean 0.67 mm), the maximum aneurysmal wall contraction was -1.91 mm to -0.34 mm (mean 0.94 mm), and the average wall displacement ranged from 0.04 mm to 0.31 mm (mean 0.15 mm). Statistically significant correlations between average wall displacement and the shape of inflow curves (p-value < 0.05) were found in 7 of 15 cross sections; statistically significant correlations between the displacement of the luminal boundary center point and the shape of inflow curves (p-value < 0.05) were found in 6 of 15 cross sections. Conclusion: 2D pcMRI in combination with QMRA is capable of visualizing and quantifying wall motion in cerebral aneurysms. However, application of this technique is currently restricted by its limited spatial resolution. (orig.)

Phase contrast MRI assessment of pedal blood flow

International Nuclear Information System (INIS)

Debatin, J.F.; Dalman, R.; Herfkens, R.J.; Harris, E.J.; Pelc, N.J.

1995-01-01

This study attempts to evaluate the reliability of cine phase contrast (PC) flow measurements in the assessment of normal pedal blood flow and quantitation of revascularisation-induced flow changes in patients with end-stage peripheral vascular occlusive disease (PVOD). Oblique axial cine-PC acquisitions were obtained on a 1.5 T MRI system at the level of the talotibial joints in 8 normal subjects on four separate occasions. Subsequently 8 patients with end-stage PVOD were examined before and after surgical revascularisation (bilateral, n = 2; unilateral, n = 6). Measured flow in the trifurcation vessels was highly variable among normal subjects. Total pedal flow ranged from 32 to 183 ml/min (mean 91 ml/min) and was significantly different between the subjects evaluated (P < 0.0001). Measurements in the same subject over time were considerably less variable (P < 0.005). Normal arterial flow patterns were consistently triphasic; those in patients with PVOD were either mono- or biphasic. Pedal flow measured by cine-PC in patients was reduced compared with normal subjects (mean 38.3 ml/min). Flow was slower in symptomatic limbs (26.7 ml/min) compared with asymptomatic ones (48.9 ml/min). Flow increases in revascularised limbs (mean 315%) were significantly different from those observed in non-affected limbs (P < 0.005). The ability to quantitate pedal blood flow and subsequent revascularisation-induced flow increases appears promising for the identification of optimal treatment options and monitoring of treatment results. (orig.)

On the system of cine-angiography

International Nuclear Information System (INIS)

Wakamatsu, Koji; Togi, Hideaki; Yokoyama, Hironori

1979-01-01

National Institute of Circulatory Disease Centre have four angiography apparatuses which deal with more than 80 cases of cerebral blood vessel and 100 cases of heart blood vessel each month. Most of the angiography is cine-photography. Five more angiography apparatuses are expected to be operated in operation and RI examination rooms in the future. The problems on cine-angiography system were discussed as follows: (1) The proper dose must be chosen in order to obtain good quality of cine-images. (2) The cine resolution depends much on dose. (3) The lower X-ray tube voltage can give better contrast. (4) Suitable capacity for an X-ray tube is over 60 kW at 2 sec rating. (5) Cine-autophotography requires rapid response and a circuit for lock. (6) Influence of side scattering can be solved by a blanking circuit in biplane cine-photography. (7) Self-developing is desirable to improve the quality of cine-images. (Kobatake, H.)

Real-time automatic fiducial marker tracking in low contrast cine-MV images

International Nuclear Information System (INIS)

Lin, Wei-Yang; Lin, Shu-Fang; Yang, Sheng-Chang; Liou, Shu-Cheng; Nath, Ravinder; Liu Wu

2013-01-01

Purpose: To develop a real-time automatic method for tracking implanted radiographic markers in low-contrast cine-MV patient images used in image-guided radiation therapy (IGRT). Methods: Intrafraction motion tracking using radiotherapy beam-line MV images have gained some attention recently in IGRT because no additional imaging dose is introduced. However, MV images have much lower contrast than kV images, therefore a robust and automatic algorithm for marker detection in MV images is a prerequisite. Previous marker detection methods are all based on template matching or its derivatives. Template matching needs to match object shape that changes significantly for different implantation and projection angle. While these methods require a large number of templates to cover various situations, they are often forced to use a smaller number of templates to reduce the computation load because their methods all require exhaustive search in the region of interest. The authors solve this problem by synergetic use of modern but well-tested computer vision and artificial intelligence techniques; specifically the authors detect implanted markers utilizing discriminant analysis for initialization and use mean-shift feature space analysis for sequential tracking. This novel approach avoids exhaustive search by exploiting the temporal correlation between consecutive frames and makes it possible to perform more sophisticated detection at the beginning to improve the accuracy, followed by ultrafast sequential tracking after the initialization. The method was evaluated and validated using 1149 cine-MV images from two prostate IGRT patients and compared with manual marker detection results from six researchers. The average of the manual detection results is considered as the ground truth for comparisons. Results: The average root-mean-square errors of our real-time automatic tracking method from the ground truth are 1.9 and 2.1 pixels for the two patients (0.26 mm/pixel). The

Real-time automatic fiducial marker tracking in low contrast cine-MV images

Energy Technology Data Exchange (ETDEWEB)

Lin, Wei-Yang; Lin, Shu-Fang; Yang, Sheng-Chang; Liou, Shu-Cheng; Nath, Ravinder; Liu Wu [Department of Computer Science and Information Engineering, National Chung Cheng University, Taiwan, 62102 (China); Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06510-3220 (United States)

2013-01-15

Purpose: To develop a real-time automatic method for tracking implanted radiographic markers in low-contrast cine-MV patient images used in image-guided radiation therapy (IGRT). Methods: Intrafraction motion tracking using radiotherapy beam-line MV images have gained some attention recently in IGRT because no additional imaging dose is introduced. However, MV images have much lower contrast than kV images, therefore a robust and automatic algorithm for marker detection in MV images is a prerequisite. Previous marker detection methods are all based on template matching or its derivatives. Template matching needs to match object shape that changes significantly for different implantation and projection angle. While these methods require a large number of templates to cover various situations, they are often forced to use a smaller number of templates to reduce the computation load because their methods all require exhaustive search in the region of interest. The authors solve this problem by synergetic use of modern but well-tested computer vision and artificial intelligence techniques; specifically the authors detect implanted markers utilizing discriminant analysis for initialization and use mean-shift feature space analysis for sequential tracking. This novel approach avoids exhaustive search by exploiting the temporal correlation between consecutive frames and makes it possible to perform more sophisticated detection at the beginning to improve the accuracy, followed by ultrafast sequential tracking after the initialization. The method was evaluated and validated using 1149 cine-MV images from two prostate IGRT patients and compared with manual marker detection results from six researchers. The average of the manual detection results is considered as the ground truth for comparisons. Results: The average root-mean-square errors of our real-time automatic tracking method from the ground truth are 1.9 and 2.1 pixels for the two patients (0.26 mm/pixel). The

Flow velocity and volume measurement of superior and inferior mesenteric artery with cine phase contrast magnetic resonance imaging

International Nuclear Information System (INIS)

Naganawa, Shinji; Cooper, T.G.; Jenner, G.; Potchen, E.J.; Ishigaki, Takeo.

1994-01-01

The flow velocity and volume of the superior and inferior mesenteric arteries (SMA, IMA) were measured with cine phase contrast magnetic resonance (MR) imaging in five healthy volunteers. Each volunteer was first measured in a fasting state, and then one, two, and three hours after a meal. The average SMA flow volume of the volunteers was 230.3±46.8 ml/min (mean±standard error) during the fasting state, and 714.7±207.7 ml/min, 339.2±85.7 ml/min, and 263.8±21.0 ml/min, respectively, at one, two, and three hours postmeal. The increase at one hour postmeal was statistically significant (p<0.05). The corresponding flow measurements in the IMA were 63.1±11.2 ml/min, 67.6±11.2 ml/min, 57.9±8.6 ml/min, and 53.2±6.8 ml/min. These values do not represent a statistically significant flow volume change in the IMA. In all volunteers, the SMA volumetric flow increased the most one hour after the food challenge (72-400% relative to baseline). Diastolic velocity in the SMA increased significantly one hour postmeal, but systolic velocity did not change significantly. The IMA did not demonstrate a significant change in either systolic or diastolic velocity. The difference between the SMA and IMA in the way of reacting against the food challenge is thought to represent the difference between the requirements of small and large intestine for blood supply after the food challenge. These data demonstrate the possibility of this modality for the assessment of conditions such as chronic mesenteric ischemia. (author)

Validation of Contrast Enhanced Cine Steady-State Free Precession and T2-Weigthed CMR for Assessment of Ischemic Myocardial Area- At-Risk

DEFF Research Database (Denmark)

Søvsø Szocska Hansen, Esben; Pedersen, Steen Fjord; Pedersen, Steen Bønløkke

2017-01-01

-CINE) has recently been used to quantify AAR and validated against myocardial perfusion SPECT. In this study we sought to determine how well T2-STIR and CE-CINE depicts AAR in an experimental porcine model of myocardial ischemia-reperfusion injury using histopathology as the reference for infarct size......Measuring myocardial salvage is important to evaluate the possible cardioprotective effects of adjunctive cardioprotective intervention in patients with myocardial infarction undergoing primary percutaneous intervention. Contrast-enhanced steady-state free precession magnetic resonance imaging (CE...

Cine-CT measurement of cortical renal blood flow

International Nuclear Information System (INIS)

Jaschke, W.R.; Gould, R.G.; Cogan, M.G.; Sievers, R.; Lipton, M.J.

1987-01-01

A modified indicator-dilution technique using radiographic contrast material and a cine-CT scanner was used to measure blood flow in the renal cortex of dogs. To validate this technique, CT measurements were correlated with simultaneous measurements of flow determined by radioactive microspheres. Measurements were taken during euvolemic conditions and after hemorrhage. Thirty-nine measurements were compared, covering a flow range from 1 to 7 ml min-1 g-1, and a good correlation was found between the cine-CT and microsphere results (r = 0.93; p less than 0.001). Additionally, cine-CT measurements were made of the mean transit time (MTT) of contrast material through the renal cortex, and the reciprocal of these MTT values was also well correlated to microsphere determined flow (r = 0.94; p less than 0.001). Thus, cine-CT appears to be a promising new technique for measuring renal blood flow

How to perform and interpret cine MR enterography.

Science.gov (United States)

Wnorowski, Amelia M; Guglielmo, Flavius F; Mitchell, Donald G

2015-11-01

Magnetic resonance (MR) enterography has become a fundamental tool for small bowel evaluation. Multiphasic cine imaging is a useful component of MR enterography evaluation because it provides functional information about bowel motility. Cine MR enterography can be used to evaluate for strictures and adhesions. Bowel motility evaluation has been shown to increase pathologic lesion detection in Crohn's disease and has been incorporated into disease activity scoring systems. Currently, cine MR enterography remains underutilized. The purpose of this article is to outline how to perform and interpret cine MR enterography. The authors describe how to perform a multiphasic balanced steady state free precession sequence using different MR systems and give practical advice on how to display and interpret the cine sequence. Sample cases illustrate how the cine sequence complements standard MR enterography evaluation with T2 -weighted, contrast-enhanced T1 -weighted, and diffusion-weighted imaging. © 2015 Wiley Periodicals, Inc.

Measurement of cerebral blood flow with two-dimensional cine phase-contrast MR imaging. Evaluation of normal subjects and patients with vertigo

Energy Technology Data Exchange (ETDEWEB)

Kashimada, Akio; Machida, Kikuo; Honda, Norinari; Mamiya, Toshio; Takahashi, Taku; Kamano, Tsuyoshi; Osada, Hisato [Saitama Medical School, Kawagoe (Japan). Saitama Medical Center

1995-03-01

The purpose of this study was to determine whether or not the vertebral flow of patients with vertigo and normal brain magnetic resonance (MR) images was decreased in comparison with normal controls. Cerebral blood flow (CBF) was quantitatively measured by a two-dimensional phase contrast cine MR imaging technique in 24 normal controls (mean age, 38.6 years; range, 12-70) and 23 patients (mean age, 53.7 years; range, 19-76) with a 1.5 Tesla MR imaging unit. Inter-and intraobserver variation in blood flow measurements was small (r=0.970, standard error of the estimate [SEE]=2.9 ml, n=80; r=0.963, SEE=4.6 ml, n=40, respectively), In the normal group, mean summed vertebral flow (171 ml/min, SD=40.6) was significantly less than mean summed carotid flow (523 ml/min, SD=111). Right vertebral flow (80.2 ml/min, SD=30.5) was less than left vertebral flow (91.2 ml/min, SD=38.2), but the difference was not statistically significant (p<0.05), In the 23 patients, although the summed vertebral flows of two patients (63.3, 88.8 ml/min) were significantly less than that of the normal group, mean summed vertebral flow (165 ml/min, SD=59.1) showed no significant difference from that of the normal group (p<0.05). In this study, the majority of patients had normal CBF. This method is clinically useful for estimating CBF. (author).

Measurement of cerebral blood flow with two-dimensional cine phase-contrast MR imaging. Evaluation of normal subjects and patients with vertigo

International Nuclear Information System (INIS)

Kashimada, Akio; Machida, Kikuo; Honda, Norinari; Mamiya, Toshio; Takahashi, Taku; Kamano, Tsuyoshi; Osada, Hisato

1995-01-01

The purpose of this study was to determine whether or not the vertebral flow of patients with vertigo and normal brain magnetic resonance (MR) images was decreased in comparison with normal controls. Cerebral blood flow (CBF) was quantitatively measured by a two-dimensional phase contrast cine MR imaging technique in 24 normal controls (mean age, 38.6 years; range, 12-70) and 23 patients (mean age, 53.7 years; range, 19-76) with a 1.5 Tesla MR imaging unit. Inter-and intraobserver variation in blood flow measurements was small (r=0.970, standard error of the estimate [SEE]=2.9 ml, n=80; r=0.963, SEE=4.6 ml, n=40, respectively), In the normal group, mean summed vertebral flow (171 ml/min, SD=40.6) was significantly less than mean summed carotid flow (523 ml/min, SD=111). Right vertebral flow (80.2 ml/min, SD=30.5) was less than left vertebral flow (91.2 ml/min, SD=38.2), but the difference was not statistically significant (p<0.05), In the 23 patients, although the summed vertebral flows of two patients (63.3, 88.8 ml/min) were significantly less than that of the normal group, mean summed vertebral flow (165 ml/min, SD=59.1) showed no significant difference from that of the normal group (p<0.05). In this study, the majority of patients had normal CBF. This method is clinically useful for estimating CBF. (author)

Cine-magnetic resonance imaging evaluation of communication between middle cranial fossa arachnoid cysts and cisterns

International Nuclear Information System (INIS)

Eguchi, Takahiko; Nikaido, Yuji; Shiomi, Kazuaki; Fujimoto, Takatoshi; Otsuka, Hiroyuki; Takeuchi, Hiroshi; Taoka, Toshiaki.

1996-01-01

Cine-magnetic resonance (MR) imaging examinations were performed in 10 patients with middle cranial fossa arachnoid cysts to evaluate communication between the cysts and the normal cerebrospinal fluid (CSF) space. Eight of 10 patients were evaluated by time of flight cine-MR imaging, and two by phase contrast cine-MR imaging. Two patients underwent membranectomy of the cysts, and were evaluated both pre-and postoperatively. Computed tomography cisternography was used to confirm communication between the cysts and the surrounding cisterns. Pulsatile fluid motion within the cysts was present in all patients. However, marked fluid motion and jet flow between the cysts and the surrounding cisterns were only observed in communicating cysts. In the two patients who underwent membranectomy, postoperative examination found greater fluid motion and jet flow not previously present. Cine-MR imaging demonstration of marked pulsatile fluid motion accompanied by jet flow suggests that a cyst communicates with the normal CSF space. (author)

Cine phase-contrast MRI measurement of CSF flow in the cervical spine: a pilot study in patients with spinal cord injury

Science.gov (United States)

Negahdar, MJ; Shakeri, M.; McDowell, E.; Wells, J.; Vitaz, T.; Harkema, S.; Amini, A.

2011-03-01

MRI velocimetry (also known as phase-contrast MRI) is a powerful tool for quantification of cerebrospinal fluid (CSF) flow in various regions of the brain and craniospinal junction and has been accepted as a diagnostic tool to assist with the diagnosis of certain conditions such as hydrocephalus and chiari malformations. Cerebrospinal fluid is continually produced in the ventricles of the brain, flows through the ventricular system and then out and around the brain and spinal cord and is reabsorbed over the convexity of the brain. Any disease process which either impedes the normal pattern of flow or restricts the area where flow occurs can change the pattern of these waveforms with the direction and velocity of flow being determined by the pressure transmitted from the pulsation of the heart and circulation of blood within the central nervous system. Therefore, we hypothesized that phase-contrast MRI could eventually be used as a diagnostic aid in determining the degree of spinal cord compression following injury to the cervical or thoracic spine. In this study, we examined CSF flow in 3 normal subjects and 2 subjects with non-acute injuries in the cervical spine using Cine phasecontrast MRI. CSF flow analysis was performed using an in-house developed software. The flow waveform was calculated in both normal subjects (n=3) as well as subjects with spinal cord injury in the cervical spine (n=2). The bulk flow at C2 was measured to be 0.30 +/- 0.05 cc, at 5 cm distal to C2, it was 0.19+/- 0.07 cc, and at 10 cm distal to C2, it was 0.17+/- 0.05 cc. These results were in good agreement with previously published results. In patients with spinal cord injury, at the site of injury in the cervical spine, bulk flow was found to be 0.08 +/- 0.12 cc, at 5 cm proximal to the site of injury it was found to be 0.18 +/- 0.07 cc, and at 5 cm distal to the site of injury, it was found to be 0.12 +/- 0.01 cc.

Validation of regional myocardial perfusion with cine CT

International Nuclear Information System (INIS)

Gould, R.G.; McNamara, T.; Koshold, S.; Lipton, M.; Sievers, R.; Higgins, C.B.; Boyd, D.

1986-01-01

Blood flow within each of eight quadrants of the myocardium was measured in dogs using a cine-CT scanner and also with microspheres. Cine-CT flow measurements were made using a nonionic contrast agent and flow was calculated by a formula that used both the maximum iodine concentration and the peak delay time. Measurements were obtained at rest and during hyperperfusion induced by chromonar. Simultaneous cine-CT and microsphere measurements correlated (slope = 0.71 r = .8) over a range of 0.4-7.0 ml/min/g

Cardiac index after acute ST-segment elevation myocardial infarction measured with phase-contrast cardiac magnetic resonance imaging

International Nuclear Information System (INIS)

Klug, Gert; Reinstadler, Sebastian Johannes; Feistritzer, Hans-Josef; Schwaiger, Johannes P.; Reindl, Martin; Mair, Johannes; Mueller, Silvana; Franz, Wolfgang-Michael; Metzler, Bernhard; Kremser, Christian; Mayr, Agnes

2016-01-01

Phase-contrast CMR (PC-CMR) might provide a fast and robust non-invasive determination of left ventricular function in patients after ST-segment elevation myocardial infarction (STEMI). Cine sequences in the left-ventricular (LV) short-axis and free-breathing, retrospectively gated PC-CMR were performed in 90 patients with first acute STEMI and 15 healthy volunteers. Inter- and intra-observer agreement was determined. The correlations of clinical variables age, gender, ejection fraction, NT pro-brain natriuretic peptide [NT-proBNP] with cardiac index (CI) were calculated. For CI, there was a strong agreement of cine CMR with PC-CMR in healthy volunteers (r: 0.82, mean difference: -0.14 l/min/m 2 , error ± 23 %). Agreement was lower in STEMI patients (r: 0.61, mean difference: -0.17 l/min/m 2 , error ± 32 %). In STEMI patients, CI measured with PC-CMR showed lower intra-observer (1 % vs. 9 %) and similar inter-observer variability (9 % vs. 12 %) compared to cine CMR. CI was significantly correlated with age, ejection fraction and NT-proBNP values in STEMI patients. The agreement of PC-CMR and cine CMR for the determination of CI is lower in STEMI patients than in healthy volunteers. After acute STEMI, CI measured with PC-CMR decreases with age, LV ejection fraction and higher NT-proBNP. (orig.)

Four-dimensional dose reconstruction through in vivo phase matching of cine images of electronic portal imaging device.

Science.gov (United States)

Yoon, Jihyung; Jung, Jae Won; Kim, Jong Oh; Yi, Byong Yong; Yeo, Inhwan

2016-07-01

A method is proposed to reconstruct a four-dimensional (4D) dose distribution using phase matching of measured cine images to precalculated images of electronic portal imaging device (EPID). (1) A phantom, designed to simulate a tumor in lung (a polystyrene block with a 3 cm diameter embedded in cork), was placed on a sinusoidally moving platform with an amplitude of 1 cm and a period of 4 s. Ten-phase 4D computed tomography (CT) images of the phantom were acquired. A planning target volume (PTV) was created by adding a margin of 1 cm around the internal target volume of the tumor. (2) Three beams were designed, which included a static beam, a theoretical dynamic beam, and a planning-optimized dynamic beam (PODB). While the theoretical beam was made by manually programming a simplistic sliding leaf motion, the planning-optimized beam was obtained from treatment planning. From the three beams, three-dimensional (3D) doses on the phantom were calculated; 4D dose was calculated by means of the ten phase images (integrated over phases afterward); serving as "reference" images, phase-specific EPID dose images under the lung phantom were also calculated for each of the ten phases. (3) Cine EPID images were acquired while the beams were irradiated to the moving phantom. (4) Each cine image was phase-matched to a phase-specific CT image at which common irradiation occurred by intercomparing the cine image with the reference images. (5) Each cine image was used to reconstruct dose in the phase-matched CT image, and the reconstructed doses were summed over all phases. (6) The summation was compared with forwardly calculated 4D and 3D dose distributions. Accounting for realistic situations, intratreatment breathing irregularity was simulated by assuming an amplitude of 0.5 cm for the phantom during a portion of breathing trace in which the phase matching could not be performed. Intertreatment breathing irregularity between the time of treatment and the time of planning CT was

Four-dimensional dose reconstruction through in vivo phase matching of cine images of electronic portal imaging device

Energy Technology Data Exchange (ETDEWEB)

Yoon, Jihyung; Jung, Jae Won, E-mail: jungj@ecu.edu [Department of Physics, East Carolina University, Greenville, North Carolina 27858 (United States); Kim, Jong Oh [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232 (United States); Yi, Byong Yong [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201 (United States); Yeo, Inhwan [Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, California 92354 (United States)

2016-07-15

Purpose: A method is proposed to reconstruct a four-dimensional (4D) dose distribution using phase matching of measured cine images to precalculated images of electronic portal imaging device (EPID). Methods: (1) A phantom, designed to simulate a tumor in lung (a polystyrene block with a 3 cm diameter embedded in cork), was placed on a sinusoidally moving platform with an amplitude of 1 cm and a period of 4 s. Ten-phase 4D computed tomography (CT) images of the phantom were acquired. A planning target volume (PTV) was created by adding a margin of 1 cm around the internal target volume of the tumor. (2) Three beams were designed, which included a static beam, a theoretical dynamic beam, and a planning-optimized dynamic beam (PODB). While the theoretical beam was made by manually programming a simplistic sliding leaf motion, the planning-optimized beam was obtained from treatment planning. From the three beams, three-dimensional (3D) doses on the phantom were calculated; 4D dose was calculated by means of the ten phase images (integrated over phases afterward); serving as “reference” images, phase-specific EPID dose images under the lung phantom were also calculated for each of the ten phases. (3) Cine EPID images were acquired while the beams were irradiated to the moving phantom. (4) Each cine image was phase-matched to a phase-specific CT image at which common irradiation occurred by intercomparing the cine image with the reference images. (5) Each cine image was used to reconstruct dose in the phase-matched CT image, and the reconstructed doses were summed over all phases. (6) The summation was compared with forwardly calculated 4D and 3D dose distributions. Accounting for realistic situations, intratreatment breathing irregularity was simulated by assuming an amplitude of 0.5 cm for the phantom during a portion of breathing trace in which the phase matching could not be performed. Intertreatment breathing irregularity between the time of treatment and the

Generalized phase contrast:

DEFF Research Database (Denmark)

Glückstad, Jesper; Palima, Darwin

Generalized Phase Contrast elevates the phase contrast technique not only to improve phase imaging but also to cross over and interface with diverse and seemingly disparate fields of contemporary optics and photonics. This book presents a comprehensive introduction to the Generalized Phase Contrast...

Free breathing whole-heart 3D CINE MRI with self-gated Cartesian trajectory.

Science.gov (United States)

Usman, M; Ruijsink, B; Nazir, M S; Cruz, G; Prieto, C

2017-05-01

To present a method that uses a novel free-running self-gated acquisition to achieve isotropic resolution in whole heart 3D Cartesian cardiac CINE MRI. 3D cardiac CINE MRI using navigator gating results in long acquisition times. Recently, several frameworks based on self-gated non-Cartesian trajectories have been proposed to accelerate this acquisition. However, non-Cartesian reconstructions are computationally expensive due to gridding, particularly in 3D. In this work, we propose a novel highly efficient self-gated Cartesian approach for 3D cardiac CINE MRI. Acquisition is performed using CArtesian trajectory with Spiral PRofile ordering and Tiny golden angle step for eddy current reduction (so called here CASPR-Tiger). Data is acquired continuously under free breathing (retrospective ECG gating, no preparation pulses interruption) for 4-5min and 4D whole-heart volumes (3D+cardiac phases) with isotropic spatial resolution are reconstructed from all available data using a soft gating technique combined with temporal total variation (TV) constrained iterative SENSE reconstruction. For data acquired on eight healthy subjects and three patients, the reconstructed images using the proposed method had good contrast and spatio-temporal variations, correctly recovering diastolic and systolic cardiac phases. Non-significant differences (P>0.05) were observed in cardiac functional measurements obtained with proposed 3D approach and gold standard 2D multi-slice breath-hold acquisition. The proposed approach enables isotropic 3D whole heart Cartesian cardiac CINE MRI in 4 to 5min free breathing acquisition. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Usefulness of true FISP cine MR imaging in patients with poor cardiac function

Energy Technology Data Exchange (ETDEWEB)

Sakuma, Toshiharu; Yamada, Naoaki; Motooka, Makoto; Enomoto, Naoyuki; Maeshima, Isamu; Matsuda, Kazuhide; Urayama, Shinichi; Ikeo, Miki [National Cardiovascular Center, Suita, Osaka (Japan)

2002-01-01

This study was done to assess the value of True FISP cine in patients with poor cardiac function. True FISP cine and FLASH cine imaging were performed on a 1.5 T machine. Both short axis and horizontal long axis imaging sections were used. The imaging sections used a Matrix (120 x 128), FOV (24 x 32 cm), and had a slice thickness of 8 mm. The imaging time for True FISP cine was 8 heart beats and 17 heart beats for FLASH cine. The contrast-to-noise ratio between the blood and myocardium (CNR) was measured at enddiastole and endsystole. The subjects in the study were 10 healty volunteers (average age 26.5{+-}3.2 years) and 12 patients with hypofunction (average age 53.9{+-}13.2 years). In the volunteers, the CNR of the short axis imaging was similar in both True FISP (24.6{+-}3.7) and FLASH (23.4{+-}5.9). In the patients with poor cardiac function however, the CNR of True FISP was larger than FLASH in both the short and long axis. In the short axis (22.7{+-}6.1 vs. 17.9{+-}5.3, P<0.01) and in the long axis (17.4{+-}4.3 vs. 9.3{+-}4.0, P<0.01). We conclude that True FISP cine has a higher contrast in a shorter imaging time than FLASH cine. True FISP cine is especially useful in patients with poor cardiac function. (author)

Functional analysis of third ventriculostomy patency with phase-contrast MRI velocity measurements

International Nuclear Information System (INIS)

Lev, S.; Bhadelia, R.A.; Estin, D.; Heilman, C.B.; Wolpert, S.M.

1997-01-01

Our purpose was to explore the utility of cine phase-contrast MRI velocity measurements in determining the functional status of third ventriculostomies, and to correlate the quantitative velocity data with clinical follow-up. We examined six patients with third ventriculostomies and 12 normal subjects by phase-contrast MRI. The maximum craniocaudal to maximum caudocranial velocity range was measured at regions of interest near the third ventricular floor, and in cerebrospinal fluid anterior to the upper pons and spinal cord on midline sagittal images. Ratios of the velocities of both the third ventricle and prepontine space to the space anterior to the spinal cord were obtained. The velocities near the third ventricular floor and in the pontine cistern were significantly higher in patients than in normal subjects, but the velocity anterior to the spinal cord was similar between the groups. The velocity ratios, used to normalize individual differences, were also higher in patients than in controls. Two patients had lower velocity ratios than their fellows at the third ventricular floor and in the pontine cistern; one required a shunt 11 months later, while in the other, who had a third ventricular/thalamic tumor, the lower values probably reflect distortion of the third ventricular floor. We conclude that phase-contrast MR velocity measurements, specifically the velocity ratio between the high pontine cistern and the space anterior to the spinal cord, can help determine the functional status of third ventriculostomies. (orig.)

Free-breathing whole-heart 3D cine magnetic resonance imaging with prospective respiratory motion compensation.

Science.gov (United States)

Moghari, Mehdi H; Barthur, Ashita; Amaral, Maria E; Geva, Tal; Powell, Andrew J

2018-07-01

To develop and validate a new prospective respiratory motion compensation algorithm for free-breathing whole-heart 3D cine steady-state free precession (SSFP) imaging. In a 3D cine SSFP sequence, 4 excitations per cardiac cycle are re-purposed to prospectively track heart position. Specifically, their 1D image is reconstructed and routed into the scanner's standard diaphragmatic navigator processing system. If all 4 signals are in end-expiration, cine image data from the entire cardiac cycle is accepted for image reconstruction. Prospective validation was carried out in patients (N = 17) by comparing in each a conventional breath-hold 2D cine ventricular short-axis stack and a free-breathing whole-heart 3D cine data set. All 3D cine SSFP acquisitions were successful and the mean scan time was 5.9 ± 2.7 min. Left and right ventricular end-diastolic, end-systolic, and stroke volumes by 3D cine SSFP were all larger than those from 2D cine SSFP. This bias was 3D cine images had a lower ventricular blood-to-myocardium contrast ratio, contrast-to-noise ratio, mass, and subjective quality score. The novel prospective respiratory motion compensation method for 3D cine SSFP imaging was robust and efficient and yielded slightly larger ventricular volumes and lower mass compared to breath-hold 2D cine imaging. Magn Reson Med 80:181-189, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Free-breathing steady-state free precession cine cardiac magnetic resonance with respiratory navigator gating.

Science.gov (United States)

Moghari, Mehdi H; Komarlu, Rukmini; Annese, David; Geva, Tal; Powell, Andrew J

2015-04-01

To develop and validate a respiratory motion compensation method for free-breathing cardiac cine imaging. A free-breathing navigator-gated cine steady-state free precession acquisition (Cine-Nav) was developed which preserves the equilibrium state of the net magnetization vector, maintains the high spatial and temporal resolutions of standard breath-hold (BH) acquisition, and images entire cardiac cycle. Cine image data is accepted only from cardiac cycles occurring entirely during end-expiration. Prospective validation was performed in 10 patients by obtaining in each three complete ventricular image stacks with different respiratory motion compensation approaches: (1) BH, (2) free-breathing with 3 signal averages (3AVG), and (3) free-breathing with Cine-Nav. The subjective image quality score (1 = worst, 4 = best) for Cine-Nav (3.8 ± 0.4) was significantly better than for 3AVG (2.2 ± 0.5, P = 0.002), and similar to BH (4.0 ± 0.0, P = 0.13). The blood-to-myocardium contrast ratio for Cine-Nav (6.3 ± 1.5) was similar to BH (5.9 ± 1.6, P = 0.52) and to 3AVG (5.6 ± 2.5, P = 0.43). There were no significant differences between Cine-Nav and BH for the ventricular volumes and mass. In contrast, there were significant differences between 3AVG and BH in all of these measurements but right ventricular mass. Free-breathing cine imaging with Cine-Nav yielded comparable image quality and ventricular measurements to BH, and was superior to 3AVG. © 2014 Wiley Periodicals, Inc.

Usefulness of true FISP cine MR imaging in patients with poor cardiac function

International Nuclear Information System (INIS)

Sakuma, Toshiharu; Yamada, Naoaki; Motooka, Makoto; Enomoto, Naoyuki; Maeshima, Isamu; Matsuda, Kazuhide; Urayama, Shinichi; Ikeo, Miki

2002-01-01

This study was done to assess the value of True FISP cine in patients with poor cardiac function. True FISP cine and FLASH cine imaging were performed on a 1.5 T machine. Both short axis and horizontal long axis imaging sections were used. The imaging sections used a Matrix (120 x 128), FOV (24 x 32 cm), and had a slice thickness of 8 mm. The imaging time for True FISP cine was 8 heart beats and 17 heart beats for FLASH cine. The contrast-to-noise ratio between the blood and myocardium (CNR) was measured at enddiastole and endsystole. The subjects in the study were 10 healty volunteers (average age 26.5±3.2 years) and 12 patients with hypofunction (average age 53.9±13.2 years). In the volunteers, the CNR of the short axis imaging was similar in both True FISP (24.6±3.7) and FLASH (23.4±5.9). In the patients with poor cardiac function however, the CNR of True FISP was larger than FLASH in both the short and long axis. In the short axis (22.7±6.1 vs. 17.9±5.3, P<0.01) and in the long axis (17.4±4.3 vs. 9.3±4.0, P<0.01). We conclude that True FISP cine has a higher contrast in a shorter imaging time than FLASH cine. True FISP cine is especially useful in patients with poor cardiac function. (author)

Peristalsis gap sign at cine magnetic resonance imaging for diagnosing strangulated small bowel obstruction. Feasibility study

International Nuclear Information System (INIS)

Takahara, Taro; Kwee, T.C.; Haradome, Hiroki

2011-01-01

The aim of this study was to determine the feasibility of cine magnetic resonance imaging (MRI) for diagnosing strangulated small bowel obstruction (SBO). This study included 38 patients with clinically confirmed SBO who had undergone cine MRI. Cine MRI scans were evaluated regarding the presence of the 'peristalsis gap sign' (referring to an akinetic or severely hypokinetic closed loop), indicating strangulation. Computed tomography (CT) was performed in 34 of 38 patients with (n=25) or without (n=9) contrast enhancement. CT images were evaluated using a combination of criteria (presence of hyperattenuation, poor contrast enhancement, mesenteric edema, wall thickening, massive ascites) indicating strangulation. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of cine MRI and CT for the diagnosis of strangulation were calculated and compared using surgical findings and the clinical course as the reference standard. Sensitivity, specificity, PPV, and NPV of cine MRI were 100%, 92.9%, 83.3%, and 100%, respectively; and those of CT (of which 26.5% was performed without contrast enhancement) were 66.7%, 92.0%, 75.0%, and 88.5%, respectively. There was no significant difference in diagnostic accuracy between the two methods (P=0.375). Cine MRI is a feasible and promising technique for diagnosing strangulation. (author)

Generalized Phase Contrast

CERN Document Server

Glückstad, Jesper

2009-01-01

Generalized Phase Contrast elevates the phase contrast technique not only to improve phase imaging but also to cross over and interface with diverse and seemingly disparate fields of contemporary optics and photonics. This book presents a comprehensive introduction to the Generalized Phase Contrast (GPC) method including an overview of the range of current and potential applications of GPC in wavefront sensing and phase imaging, structured laser illumination and image projection, optical trapping and manipulation, and optical encryption and decryption. The GPC method goes further than the restrictive assumptions of conventional Zernike phase contrast analysis and achieves an expanded range of validity beyond weak phase perturbations. The generalized analysis yields design criteria for tuning experimental parameters to achieve optimal performance in terms of accuracy, fidelity and light efficiency. Optimization can address practical issues, such as finding an optimal spatial filter for the chosen application, ...

Automated Motion Estimation for 2D Cine DENSE MRI

Science.gov (United States)

Gilliam, Andrew D.; Epstein, Frederick H.

2013-01-01

Cine displacement encoding with stimulated echoes (DENSE) is a magnetic resonance (MR) method that directly encodes tissue displacement into MR phase images. This technique has successfully interrogated many forms of tissue motion, but is most commonly used to evaluate cardiac mechanics. Currently, motion analysis from cine DENSE images requires manually delineated anatomical structures. An automated analysis would improve measurement throughput, simplify data interpretation, and potentially access important physiological information during the MR exam. In this article, we present the first fully automated solution for the estimation of tissue motion and strain from 2D cine DENSE data. Results using both simulated and human cardiac cine DENSE data indicate good agreement between the automated algorithm and the standard semi-manual analysis method. PMID:22575669

Digital cine-imaging

International Nuclear Information System (INIS)

Masuda, Kazuhiro

1992-01-01

Digitization of fluoroscopic images has been developed for the digital cine imaging system as a result of the computer technology, television technology, and popularization of interventional radiology. Present digital cine imaging system is able to offer images similar to cine film because of the higher operatability and better image quality with the development of interventional radiology. As a result, its higher usefulness for catheter diagnosis examination except for interventional radiology was reported, and the possibility of having filmless cine is close to becoming a reality. However several problems have been pointed out, such as spatial resolution, time resolution, storage and exchangeability of data, disconsolidated viewing functions, etc. Anyhow, digital cine imaging system has some unresolved points and lots the needs to be discussed. The tendency of digitization is the passage of the time and we have to promote a study for more useful digital cine imaging system in team medical treatment which centers on the patients. (author)

Identification and Assessment of Paradoxical Ventricular Wall Motion Using ECG Gated Blood Pool Scan - Comparison of cine Loop , Phase Analysis and Paradox Image -

International Nuclear Information System (INIS)

Lee, Jae Tae; Kim, Gwang Weon; Lee, Kyu Bo; Chung, Byung Chun; Whang, Kee Suk; Chae, Sung Chul; Paek, Wee Hyun; Cheon, Jae Eun; Lee, Hyong Woo; Chung, Jin Hong

1990-01-01

Sixty-four patients with paradoxical ventricular wall motion noticed both in angiocardiography or 2-dimensional echocardiography were assessed by ECG gated blood pool scan (GBPS). Endless cine loop image, phase and amplitude images and paradox image obtained by visual inspection of each cardiac beat or Fourier transformation of acquired raw data were investigated to determine the incremental value of GBPS with these processing methods for identification of paradoxical ventricular wall motion. The results were as follows:1) Paradoxical wall motions were observed on interventricular septum in 34 cases, left ventricular free wall in 26 and right ventricular wall in 24. Underlying heart diseases were is chemic (23 cases) valvular(9), congenital heart disease (12), cardiomyopathy (5), pericardial effusion(5), post cardiac surgery(3), corpulmonale (2), endocarditis (l) and right ventricular tumor(l). 2) Left ventricular ejection fractions of patients with paradoxical left ventricular wall motion were significantly lower than those with paradoxical septal motion (p <0.005). 3) The sensitivity of each processing methods for detecting paradoxical wall motion was 76.9% by phase analysis, 74.6% by endless cine loop mapping and 68.4% by paradox image manipulation respectively. Paradoxial motions visualized only in phase, paradox or both images were appeared as hypokinesia or akinesia in cine loop image. 4) All events could be identified by at least one of above three processing methods, however only 34 cases (48.4%) showed the paradoxical motions in all of the three images. By these findings, we concluded that simultaneous inspection of all above three processing methods-endless cine loop, phase analysis and paradox image is necessary for accurate identification and assessment of paradoxical ventricular wall motion when performing GBPS.

Identification and Assessment of Paradoxical Ventricular Wall Motion Using ECG Gated Blood Pool Scan - Comparison of cine Loop , Phase Analysis and Paradox Image -

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Tae; Kim, Gwang Weon; Lee, Kyu Bo; Chung, Byung Chun; Whang, Kee Suk; Chae, Sung Chul; Paek, Wee Hyun; Cheon, Jae Eun [Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Lee, Hyong Woo; Chung, Jin Hong [Yeongnam National University College of Medicine, Daegu (Korea, Republic of)

1990-07-15

Sixty-four patients with paradoxical ventricular wall motion noticed both in angiocardiography or 2-dimensional echocardiography were assessed by ECG gated blood pool scan (GBPS). Endless cine loop image, phase and amplitude images and paradox image obtained by visual inspection of each cardiac beat or Fourier transformation of acquired raw data were investigated to determine the incremental value of GBPS with these processing methods for identification of paradoxical ventricular wall motion. The results were as follows:1) Paradoxical wall motions were observed on interventricular septum in 34 cases, left ventricular free wall in 26 and right ventricular wall in 24. Underlying heart diseases were is chemic (23 cases) valvular(9), congenital heart disease (12), cardiomyopathy (5), pericardial effusion(5), post cardiac surgery(3), corpulmonale (2), endocarditis (l) and right ventricular tumor(l). 2) Left ventricular ejection fractions of patients with paradoxical left ventricular wall motion were significantly lower than those with paradoxical septal motion (p <0.005). 3) The sensitivity of each processing methods for detecting paradoxical wall motion was 76.9% by phase analysis, 74.6% by endless cine loop mapping and 68.4% by paradox image manipulation respectively. Paradoxial motions visualized only in phase, paradox or both images were appeared as hypokinesia or akinesia in cine loop image. 4) All events could be identified by at least one of above three processing methods, however only 34 cases (48.4%) showed the paradoxical motions in all of the three images. By these findings, we concluded that simultaneous inspection of all above three processing methods-endless cine loop, phase analysis and paradox image is necessary for accurate identification and assessment of paradoxical ventricular wall motion when performing GBPS.

Investigating the limitations of single breath-hold renal artery blood flow measurements using spiral phase contrast MR with R-R interval averaging.

Science.gov (United States)

Steeden, Jennifer A; Muthurangu, Vivek

2015-04-01

1) To validate an R-R interval averaged golden angle spiral phase contrast magnetic resonance (RAGS PCMR) sequence against conventional cine PCMR for assessment of renal blood flow (RBF) in normal volunteers; and 2) To investigate the effects of motion and heart rate on the accuracy of flow measurements using an in silico simulation. In 20 healthy volunteers RAGS (∼6 sec breath-hold) and respiratory-navigated cine (∼5 min) PCMR were performed in both renal arteries to assess RBF. A simulation of RAGS PCMR was used to assess the effect of heart rate (30-105 bpm), vessel expandability (0-150%) and translational motion (x1.0-4.0) on the accuracy of RBF measurements. There was good agreement between RAGS and cine PCMR in the volunteer study (bias: 0.01 L/min, limits of agreement: -0.04 to +0.06 L/min, P = 0.0001). The simulation demonstrated a positive linear relationship between heart rate and error (r = 0.9894, P 100 bpm), or when there is significant motion (vessel expandability: >80%, vessel translation: >x2.2). © 2014 Wiley Periodicals, Inc.

Using the phase-space imager to analyze partially coherent imaging systems: bright-field, phase contrast, differential interference contrast, differential phase contrast, and spiral phase contrast

Science.gov (United States)

Mehta, Shalin B.; Sheppard, Colin J. R.

2010-05-01

Various methods that use large illumination aperture (i.e. partially coherent illumination) have been developed for making transparent (i.e. phase) specimens visible. These methods were developed to provide qualitative contrast rather than quantitative measurement-coherent illumination has been relied upon for quantitative phase analysis. Partially coherent illumination has some important advantages over coherent illumination and can be used for measurement of the specimen's phase distribution. However, quantitative analysis and image computation in partially coherent systems have not been explored fully due to the lack of a general, physically insightful and computationally efficient model of image formation. We have developed a phase-space model that satisfies these requirements. In this paper, we employ this model (called the phase-space imager) to elucidate five different partially coherent systems mentioned in the title. We compute images of an optical fiber under these systems and verify some of them with experimental images. These results and simulated images of a general phase profile are used to compare the contrast and the resolution of the imaging systems. We show that, for quantitative phase imaging of a thin specimen with matched illumination, differential phase contrast offers linear transfer of specimen information to the image. We also show that the edge enhancement properties of spiral phase contrast are compromised significantly as the coherence of illumination is reduced. The results demonstrate that the phase-space imager model provides a useful framework for analysis, calibration, and design of partially coherent imaging methods.

Phase contrast image synthesis

DEFF Research Database (Denmark)

Glückstad, J.

1996-01-01

A new method is presented for synthesizing arbitrary intensity patterns based on phase contrast imaging. The concept is grounded on an extension of the Zernike phase contrast method into the domain of full range [0; 2 pi] phase modulation. By controlling the average value of the input phase funct...... function and by choosing appropriate phase retardation at the phase contrast filter, a pure phase to intensity imaging is accomplished. The method presented is also directly applicable in dark field image synthesis....

Evaluation of valvular regurgitation by cine magnetic resonance imaging in patients with various cardiac diseases

International Nuclear Information System (INIS)

Kubota, Shuuhei; Nishimura, Tsunehiko

1990-01-01

In order to evaluate the clinical value and limitation of magnetic resonance imaging (MRI) for detection and quantification of valvular regurgitation, 98 patients with various cardiac diseases were studied by cine MRI and the results were compared with contrast angiography and doppler color-flow imaging. Cine MRI was carried out using FLASH (fast low angle shot) which employs TE of 10∼20 msec and TR of 30∼40 msec. 22 transverse tomograms per cardiac cycle with a slice thickness of 10 mm were obtained at the level of atrium and ventricle. The jet of valvular regurgitation was easily seen as a discrete are of low signal with cine MRI. Identification of the regurgitation and its severity were visually evaluated based on the relative size of the regurgitant jet from the incompetent valve orifice. Using contrast angiography as a gold standard, the sensitivity of cine MRI for detecting mitral regurgitation was 83% and was 94% for aortic regurgitation, with the specificity of 82% and 100%, respectively. For mitral requrgitation and aortic regurgitation, evaluation by cine MRI and severity agreed well with contrast angiography. By the comparative study with doppler color-flow imaging, relatively good agreement was found between the two methods in detection and quantitative evaluation of valvular regurgitation in any of four valves. Cine MRI was suggested to be useful for both the detection and semiquantification of valvular regurgitation in generally, but its clinical limitation at this point was also found because, 1)its images are not acquired in real times, as in contrast angiography or doppler color-flow imaging, but are compiled from the cumulative information from 128 heart beats, 2)the evaluation of regurgitation is made from only two-dimensional transverse tomograms. (author)

Single-breath-hold 3-D CINE imaging of the left ventricle using Cartesian sampling.

Science.gov (United States)

Wetzl, Jens; Schmidt, Michaela; Pontana, François; Longère, Benjamin; Lugauer, Felix; Maier, Andreas; Hornegger, Joachim; Forman, Christoph

2018-02-01

Our objectives were to evaluate a single-breath-hold approach for Cartesian 3-D CINE imaging of the left ventricle with a nearly isotropic resolution of [Formula: see text] and a breath-hold duration of [Formula: see text]19 s against a standard stack of 2-D CINE slices acquired in multiple breath-holds. Validation is performed with data sets from ten healthy volunteers. A Cartesian sampling pattern based on the spiral phyllotaxis and a compressed sensing reconstruction method are proposed to allow 3-D CINE imaging with high acceleration factors. The fully integrated reconstruction uses multiple graphics processing units to speed up the reconstruction. The 2-D CINE and 3-D CINE are compared based on ventricular function parameters, contrast-to-noise ratio and edge sharpness measurements. Visual comparisons of corresponding short-axis slices of 2-D and 3-D CINE show an excellent match, while 3-D CINE also allows reformatting to other orientations. Ventricular function parameters do not significantly differ from values based on 2-D CINE imaging. Reconstruction times are below 4 min. We demonstrate single-breath-hold 3-D CINE imaging in volunteers and three example patient cases, which features fast reconstruction and allows reformatting to arbitrary orientations.

Assessment of left ventricular hemodynamics by Gd-DTPA enhanced high speed cine MRI

International Nuclear Information System (INIS)

Matsumura, Kentaro; Nakase, Emiko; Kawai, Ichiro

1992-01-01

To assess the validity of Gd-DTPA enhanced high speed cine MRI in left ventricular (LV) volumes and ejection fraction (EF), high speed cine MRI was compared with intra-venous digital subtraction left ventriculography (IV-DSA) in 14 patients. All patients underwent conventional cine MRI and Gd-DTPA enhanced high speed MRI, simultaneously. The pulse sequences of high speed MRI were TR 8 ms (TR 6 ms plus rewind pulse 2 ms), TE 3.2 ms, matrix 128, phase encode 8 or 6 and NEX 1. Comparison with LV-volume showed a high correlation (y = 0.854x + 1,699, r = 0.985) between high speed cine MRI and VI-DSA. To make left ventricular volume curve by area-length method in cine MRI, manual tracing of LV-cavity was more difficult in conventional cine MRI-method than enhanced high speed cine MRI-method. In conclusion, first pass-Gd-DTPA enhanced high speed cine MRI, using the horizontal long axis approach and the multiphase study, is a highly, accurate reproducible method of evaluating LV-volumetry. (author)

Automated segmentation of blood-flow regions in large thoracic arteries using 3D-cine PC-MRI measurements.

Science.gov (United States)

van Pelt, Roy; Nguyen, Huy; ter Haar Romeny, Bart; Vilanova, Anna

2012-03-01

Quantitative analysis of vascular blood flow, acquired by phase-contrast MRI, requires accurate segmentation of the vessel lumen. In clinical practice, 2D-cine velocity-encoded slices are inspected, and the lumen is segmented manually. However, segmentation of time-resolved volumetric blood-flow measurements is a tedious and time-consuming task requiring automation. Automated segmentation of large thoracic arteries, based solely on the 3D-cine phase-contrast MRI (PC-MRI) blood-flow data, was done. An active surface model, which is fast and topologically stable, was used. The active surface model requires an initial surface, approximating the desired segmentation. A method to generate this surface was developed based on a voxel-wise temporal maximum of blood-flow velocities. The active surface model balances forces, based on the surface structure and image features derived from the blood-flow data. The segmentation results were validated using volunteer studies, including time-resolved 3D and 2D blood-flow data. The segmented surface was intersected with a velocity-encoded PC-MRI slice, resulting in a cross-sectional contour of the lumen. These cross-sections were compared to reference contours that were manually delineated on high-resolution 2D-cine slices. The automated approach closely approximates the manual blood-flow segmentations, with error distances on the order of the voxel size. The initial surface provides a close approximation of the desired luminal geometry. This improves the convergence time of the active surface and facilitates parametrization. An active surface approach for vessel lumen segmentation was developed, suitable for quantitative analysis of 3D-cine PC-MRI blood-flow data. As opposed to prior thresholding and level-set approaches, the active surface model is topologically stable. A method to generate an initial approximate surface was developed, and various features that influence the segmentation model were evaluated. The active surface

Frequency analyses of CSF flow on cine MRI in normal pressure hydrocephalus

Energy Technology Data Exchange (ETDEWEB)

Miyati, Tosiaki; Kasuga, Toshio; Koshida, Kichiro; Sanada, Shigeru; Onoguchi, Masahisa [Department of Radiological Technology, School of Health Sciences, Faculty of Medicine, Kanazawa University, 5-11-80, Kodatsuno, Kanazawa, Ishikawa 920-0942 (Japan); Mase, Mitsuhito; Yamada, Kazuo [Department of Neurosurgery, Nagoya City University Medical School, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8602 (Japan); Banno, Tatsuo [Department of Central Radiology, Nagoya City University Hospital, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8602 (Japan); Fujita, Hiroshi [Department of Information Science, Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu 501-1193 (Japan)

2003-05-01

Our objective was to clarify intracranial cerebrospinal fluid (CSF) flow dynamics in normal-pressure hydrocephalus (NPH). Frequency analyses of CSF flow measured with phase-contrast cine MRI were performed. The CSF flow spectra in the aqueduct were determined in patients (n=51) with NPH, brain atrophy or asymptomatic ventricular dilation (VD), and in healthy volunteers (control group; n=25). The changes in CSF flow spectra were also analyzed after intravenous injection of acetazolamide. Moreover, a phase transfer function (PTF) calculated from the spectra of the driving vascular pulsation and CSF flow in the aqueduct were assessed. These values were compared with the pressure volume response (PVR). The amplitude in the NPH group was significantly larger than that in the VD or control group because of a decrease in compliance. The phase in the NPH group was significantly different from that in either the VD or the control group, but no difference was found between the VD and control groups. The amplitude increased in all groups after acetazolamide injection. The PTF in the NPH group was significantly larger than in the control group, and a positive correlation was noted between PTF and PVR. Frequency analyses of CSF flow measured by cine MRI make it possible to noninvasively obtain a more detailed picture of the pathophysiology of NPH. (orig.)

Comparison of fluoro and cine coronary angiography: balancing acceptable outcomes with a reduction in radiation dose.

Science.gov (United States)

Olcay, Ayhan; Guler, Ekrem; Karaca, Ibrahim Oguz; Omaygenc, Mehmet Onur; Kizilirmak, Filiz; Olgun, Erkam; Yenipinar, Esra; Cakmak, Huseyin Altug; Duman, Dursun

2015-04-01

Use of last fluoro hold (LFH) mode in fluoroscopy, which enables the last live image to be saved and displayed, could reduce radiation during percutaneous coronary intervention when compared with cine mode. No previous study compared coronary angiography radiation doses and image quality between LFH and conventional cine mode techniques. We compared cumulative dose-area product (DAP), cumulative air kerma, fluoroscopy time, contrast use, interobserver variability of visual assessment between LFH angiography, and conventional cine angiography techniques. Forty-six patients were prospectively enrolled into the LFH group and 82 patients into the cine angiography group according to operator decision. Mean cumulative DAP was higher in the cine group vs the LFH group (50058.98 ± 53542.71 mGy•cm² vs 11349.2 ± 8796.46 mGy•cm²; Pcine group vs the LFH group (3.87 ± 5.08 minutes vs 1.66 ± 1.51 minutes; Pcine group vs the LFH group (112.07 ± 43.79 cc vs 88.15 ± 23.84 cc; Pcine and LFH angiography groups (0.66680 ± 0.19309 vs 0.54193 ± 0.31046; P=.20). Radiation doses, contrast use, and fluoroscopy times are lower in fluoroscopic LFH angiography vs cine angiography. Interclass variability of visual stenosis estimation between three operators was not different between cine and LFH groups. Fluoroscopic LFH images conventionally have inferior diagnostic quality when compared with cine coronary angiography, but with new angiographic systems with improved LFH image quality, these images may be adequate for diagnostic coronary angiography.

Phase-contrast cerebrospinal fluid flow magnetic resonance imaging in qualitative evaluation of patency of CSF flow pathways prior to infusion of chemotherapeutic and other agents into the fourth ventricle.

Science.gov (United States)

Patel, Rajan P; Sitton, Clark W; Ketonen, Leena M; Hou, Ping; Johnson, Jason M; Romo, Seferino; Fletcher, Stephen; Shah, Manish N; Kerr, Marcia; Zaky, Wafik; Rytting, Michael E; Khatua, Soumen; Sandberg, David I

2018-03-01

Nuclear medicine studies have previously been utilized to assess for blockage of cerebrospinal fluid (CSF) flow prior to intraventricular chemotherapy infusions. To assess CSF flow without nuclear medicine studies, we obtained cine phase-contrast MRI sequences that assess CSF flow from the fourth ventricle down to the sacrum. In three clinical trials, 18 patients with recurrent malignant posterior fossa tumors underwent implantation of a ventricular access device (VAD) into the fourth ventricle, either with or without simultaneous tumor resection. Prior to infusing therapeutic agents into the VAD, cine MRI phase-contrast CSF flow sequences of the brain and total spine were performed. Velocity encoding (VENC) of 5 and 10 cm/s was used to confirm CSF flow from the fourth ventricular outlets to the cervical, thoracic, and lumbar spine. Qualitative CSF flow was characterized by neuroradiologists as present or absent. All 18 patients demonstrated CSF flow from the outlets of the fourth ventricle down to the sacrum with no evidence of obstruction. One of these patients, after disease progression, subsequently showed obstruction of CSF flow. No patient required a nuclear medicine study to assess CSF flow prior to initiation of infusions. Fourteen patients have received infusions to date, and none has had neurological toxicity. CSF flow including the fourth ventricle and the total spine can be assessed noninvasively with phase-contrast MRI sequences. Advantages over nuclear medicine studies include avoiding both an invasive procedure and radiation exposure.

Evaluation of aortic regurgitation using cine magnetic resonance imaging

International Nuclear Information System (INIS)

Tamai, Takuya; Konishi, Tokuji; Okamoto, Shinya; Sakuma, Hajime; Takeda, Kan; Nakano, Takeshi

1993-01-01

Cine magnetic resonance imaging (MRI) was used to assess aortic regurgitation (AR) in 13 patients with valvular disease and 3 normal subjects, and the results were compared to color Doppler flow mapping findings. AR produced a signal void in the left ventricle during the diastolic phase in all patients by MRI. There were no false positive or negative results compared with echocardiographic findings. Visual grading of cine MRI gave results similar to color flow Doppler echocardiography (88%). The distance and the area of aortic regurgitation using MRI correlated well with color Doppler flow mapping (r=0.82 and 0.88). However, measurements of distance and area by color flow Doppler tended to be larger than those by cine MRI. With current techniques echocardiography may overestimate the severity of AR as compared with cine MRI. In addition, MRI gives clinically useful information in patients in whom transthoracic Doppler echocardiography is not adequate. (author)

Comparative assessment of liver tumor motion using cine-magnetic resonance imaging versus 4-dimensional computed tomography.

Science.gov (United States)

Fernandes, Annemarie T; Apisarnthanarax, Smith; Yin, Lingshu; Zou, Wei; Rosen, Mark; Plastaras, John P; Ben-Josef, Edgar; Metz, James M; Teo, Boon-Keng

2015-04-01

To compare the extent of tumor motion between 4-dimensional CT (4DCT) and cine-MRI in patients with hepatic tumors treated with radiation therapy. Patients with liver tumors who underwent 4DCT and 2-dimensional biplanar cine-MRI scans during simulation were retrospectively reviewed to determine the extent of target motion in the superior-inferior, anterior-posterior, and lateral directions. Cine-MRI was performed over 5 minutes. Tumor motion from MRI was determined by tracking the centroid of the gross tumor volume using deformable image registration. Motion estimates from 4DCT were performed by evaluation of the fiducial, residual contrast (or liver contour) positions in each CT phase. Sixteen patients with hepatocellular carcinoma (n=11), cholangiocarcinoma (n=3), and liver metastasis (n=2) were reviewed. Cine-MRI motion was larger than 4DCT for the superior-inferior direction in 50% of patients by a median of 3.0 mm (range, 1.5-7 mm), the anterior-posterior direction in 44% of patients by a median of 2.5 mm (range, 1-5.5 mm), and laterally in 63% of patients by a median of 1.1 mm (range, 0.2-4.5 mm). Cine-MRI frequently detects larger differences in hepatic intrafraction tumor motion when compared with 4DCT most notably in the superior-inferior direction, and may be useful when assessing the need for or treating without respiratory management, particularly in patients with unreliable 4DCT imaging. Margins wider than the internal target volume as defined by 4DCT were required to encompass nearly all the motion detected by cine-MRI for some of the patients in this study. Copyright © 2015 Elsevier Inc. All rights reserved.

Measurement of cerebral blood flow in normal subjects by phase contrast MR imaging

International Nuclear Information System (INIS)

Kashimada, Akio; Machida, Kikuo; Honda, Norinari; Mamiya, Toshio; Takahashi, Taku; Kamano, Tsuyoshi; Inoue, Yusuke; Osada, Hisato

1994-01-01

Global cerebral blood flow (CBF) was quantitatively measured with a two-dimensional phase contrast cine magnetic resonance (MR) imaging technique in 24 normal subjects (mean age, 38.6 years; range, 12-70 years). Cine transverse images of the upper cervical region (32 phases/cardiac cycle) were acquired with a 1.5 Tesla MR imaging unit. In five subjects, measurement of CBF was performed before and after intravenous administration of acetazolamide (DIAMOX, 15 mg/kg). Inter- and intra-observer variations in flow volume measurement were small (r=0.970, standard error of the estimate (SEE)=2.9 ml/min, n=8; r=0.963, SEE=4.6 ml/min, n=40, respectively). In measuring flow velocity, they were inferior to those of flow volume measurement. On a visually determined setting of region of interest (ROI), reproducibility of the measurement of flow velocity was not satisfactory in this study. Thus only the results of flow volume measurement are presented. Mean summed vertebral flow volume (171 ml/min, SD=40.6) was significantly less than mean summed internal carotid flow volume (523 ml/min, SD=111). Total blood flow volume showed a significant decline with age (r=-0.45, p<0.05). The mean proportions of carotid and vertebral flow volume to total flow volume were 75.3% and 24.7%, respectively, and showed no significant change with age. The left-to-right ratio of vertebral flow volume (1.39) was significantly higher than that of internal carotid flow volume (0.99, r=0.05). After DIAMOX i.v., the mean rate of increase in total flow volume was 157%. Mean rates of increase in carotid and vertebral flow volume were 154% and 166%, respectively, which were not significantly different. In conclusion, this method is useful for estimating carotid and vertebral flow volume. (author)

Strain analysis in CRT candidates using the novel segment length in cine (SLICE) post-processing technique on standard CMR cine images

Energy Technology Data Exchange (ETDEWEB)

Zweerink, Alwin; Allaart, Cornelis P.; Wu, LiNa; Beek, Aernout M.; Rossum, Albert C. van; Nijveldt, Robin [VU University Medical Center, Department of Cardiology, and Institute for Cardiovascular Research (ICaR-VU), Amsterdam (Netherlands); Kuijer, Joost P.A. [VU University Medical Center, Department of Physics and Medical Technology, Amsterdam (Netherlands); Ven, Peter M. van de [VU University Medical Center, Department of Epidemiology and Biostatistics, Amsterdam (Netherlands); Meine, Mathias [University Medical Center, Department of Cardiology, Utrecht (Netherlands); Croisille, Pierre; Clarysse, Patrick [Univ Lyon, UJM-Saint-Etienne, INSA, CNRS UMR 5520, INSERM U1206, CREATIS, Saint-Etienne (France)

2017-12-15

Although myocardial strain analysis is a potential tool to improve patient selection for cardiac resynchronization therapy (CRT), there is currently no validated clinical approach to derive segmental strains. We evaluated the novel segment length in cine (SLICE) technique to derive segmental strains from standard cardiovascular MR (CMR) cine images in CRT candidates. Twenty-seven patients with left bundle branch block underwent CMR examination including cine imaging and myocardial tagging (CMR-TAG). SLICE was performed by measuring segment length between anatomical landmarks throughout all phases on short-axis cines. This measure of frame-to-frame segment length change was compared to CMR-TAG circumferential strain measurements. Subsequently, conventional markers of CRT response were calculated. Segmental strains showed good to excellent agreement between SLICE and CMR-TAG (septum strain, intraclass correlation coefficient (ICC) 0.76; lateral wall strain, ICC 0.66). Conventional markers of CRT response also showed close agreement between both methods (ICC 0.61-0.78). Reproducibility of SLICE was excellent for intra-observer testing (all ICC ≥0.76) and good for interobserver testing (all ICC ≥0.61). The novel SLICE post-processing technique on standard CMR cine images offers both accurate and robust segmental strain measures compared to the 'gold standard' CMR-TAG technique, and has the advantage of being widely available. (orig.)

Strain analysis in CRT candidates using the novel segment length in cine (SLICE) post-processing technique on standard CMR cine images

International Nuclear Information System (INIS)

Zweerink, Alwin; Allaart, Cornelis P.; Wu, LiNa; Beek, Aernout M.; Rossum, Albert C. van; Nijveldt, Robin; Kuijer, Joost P.A.; Ven, Peter M. van de; Meine, Mathias; Croisille, Pierre; Clarysse, Patrick

2017-01-01

Although myocardial strain analysis is a potential tool to improve patient selection for cardiac resynchronization therapy (CRT), there is currently no validated clinical approach to derive segmental strains. We evaluated the novel segment length in cine (SLICE) technique to derive segmental strains from standard cardiovascular MR (CMR) cine images in CRT candidates. Twenty-seven patients with left bundle branch block underwent CMR examination including cine imaging and myocardial tagging (CMR-TAG). SLICE was performed by measuring segment length between anatomical landmarks throughout all phases on short-axis cines. This measure of frame-to-frame segment length change was compared to CMR-TAG circumferential strain measurements. Subsequently, conventional markers of CRT response were calculated. Segmental strains showed good to excellent agreement between SLICE and CMR-TAG (septum strain, intraclass correlation coefficient (ICC) 0.76; lateral wall strain, ICC 0.66). Conventional markers of CRT response also showed close agreement between both methods (ICC 0.61-0.78). Reproducibility of SLICE was excellent for intra-observer testing (all ICC ≥0.76) and good for interobserver testing (all ICC ≥0.61). The novel SLICE post-processing technique on standard CMR cine images offers both accurate and robust segmental strain measures compared to the 'gold standard' CMR-TAG technique, and has the advantage of being widely available. (orig.)

Radial k-t SPIRiT: autocalibrated parallel imaging for generalized phase-contrast MRI.

Science.gov (United States)

Santelli, Claudio; Schaeffter, Tobias; Kozerke, Sebastian

2014-11-01

To extend SPIRiT to additionally exploit temporal correlations for highly accelerated generalized phase-contrast MRI and to compare the performance of the proposed radial k-t SPIRiT method relative to frame-by-frame SPIRiT and radial k-t GRAPPA reconstruction for velocity and turbulence mapping in the aortic arch. Free-breathing navigator-gated two-dimensional radial cine imaging with three-directional multi-point velocity encoding was implemented and fully sampled data were obtained in the aortic arch of healthy volunteers. Velocities were encoded with three different first gradient moments per axis to permit quantification of mean velocity and turbulent kinetic energy. Velocity and turbulent kinetic energy maps from up to 14-fold undersampled data were compared for k-t SPIRiT, frame-by-frame SPIRiT, and k-t GRAPPA relative to the fully sampled reference. Using k-t SPIRiT, improvements in magnitude and velocity reconstruction accuracy were found. Temporally resolved magnitude profiles revealed a reduction in spatial blurring with k-t SPIRiT compared with frame-by-frame SPIRiT and k-t GRAPPA for all velocity encodings, leading to improved estimates of turbulent kinetic energy. k-t SPIRiT offers improved reconstruction accuracy at high radial undersampling factors and hence facilitates the use of generalized phase-contrast MRI for routine use. Copyright © 2013 Wiley Periodicals, Inc.

Música y Cine

OpenAIRE

Olarte Martínez, Matilde María

2008-01-01

Materiales de clase: Introducción a la Historia de la Música en el Cine; partituras de cine mudo; música clásica y cine; textos sobre música incidental. Se Analiza la música utilizada en cinematografía, y el estudio de sus funciones aplicada a la imagen. Audiciones de música incidental y música preexistente de los principales compositores. la música utilizada en cinematografía, y el estudio de sus funciones aplicada a la imagen. Audiciones de música incidental y música preexistente de los ...

Improved attenuation correction for respiratory gated PET/CT with extended-duration cine CT: a simulation study

Science.gov (United States)

Zhang, Ruoqiao; Alessio, Adam M.; Pierce, Larry A.; Byrd, Darrin W.; Lee, Tzu-Cheng; De Man, Bruno; Kinahan, Paul E.

2017-03-01

Due to the wide variability of intra-patient respiratory motion patterns, traditional short-duration cine CT used in respiratory gated PET/CT may be insufficient to match the PET scan data, resulting in suboptimal attenuation correction that eventually compromises the PET quantitative accuracy. Thus, extending the duration of cine CT can be beneficial to address this data mismatch issue. In this work, we propose to use a long-duration cine CT for respiratory gated PET/CT, whose cine acquisition time is ten times longer than a traditional short-duration cine CT. We compare the proposed long-duration cine CT with the traditional short-duration cine CT through numerous phantom simulations with 11 respiratory traces measured during patient PET/CT scans. Experimental results show that, the long-duration cine CT reduces the motion mismatch between PET and CT by 41% and improves the overall reconstruction accuracy by 42% on average, as compared to the traditional short-duration cine CT. The long-duration cine CT also reduces artifacts in PET images caused by misalignment and mismatch between adjacent slices in phase-gated CT images. The improvement in motion matching between PET and CT by extending the cine duration depends on the patient, with potentially greater benefits for patients with irregular breathing patterns or larger diaphragm movements.

Pulmonary branch arterial flow can be measured with cine MR velocity mapping

International Nuclear Information System (INIS)

Caputo, G.R.; Kondo, C.; Masui, T.; Foster, E.; Geraci, S.J.; O'Sullivan, M.; Higgins, C.B.

1990-01-01

This paper assesses the capability of cine MR phase velocity mapping (CVM) to measure main, right-sided, and left-sided pulmonary arterial (PA) blood flow. The authors examined a constant-flow phantom and nine healthy volunteers with use of 1.5-T MR imaging system (GE Signa) with phase velocity cine sequences. CVM correctly measured constant-flow phantom velocities (range, 20-190 cm/sec; r = .998, SEE = 4.2 cm/sec), and velocity with use of angulated planes to section the phantom tube perpendicularly. CVM peak systolic main PA velocity (79 cm/sec ± 10) correlated well with Doppler US measurements (80 cm/sec ± 7). CVM main PA flow correlated well with conventional cine MR LV stroke volume measurements (r = .98, SEE = 4.8 mL). Left and right PA flow on the angulated planes were 29 mL ± 7 and 34 mL ± 10, respectively

Strain analysis in CRT candidates using the novel segment length in cine (SLICE) post-processing technique on standard CMR cine images.

Science.gov (United States)

Zweerink, Alwin; Allaart, Cornelis P; Kuijer, Joost P A; Wu, LiNa; Beek, Aernout M; van de Ven, Peter M; Meine, Mathias; Croisille, Pierre; Clarysse, Patrick; van Rossum, Albert C; Nijveldt, Robin

2017-12-01

Although myocardial strain analysis is a potential tool to improve patient selection for cardiac resynchronization therapy (CRT), there is currently no validated clinical approach to derive segmental strains. We evaluated the novel segment length in cine (SLICE) technique to derive segmental strains from standard cardiovascular MR (CMR) cine images in CRT candidates. Twenty-seven patients with left bundle branch block underwent CMR examination including cine imaging and myocardial tagging (CMR-TAG). SLICE was performed by measuring segment length between anatomical landmarks throughout all phases on short-axis cines. This measure of frame-to-frame segment length change was compared to CMR-TAG circumferential strain measurements. Subsequently, conventional markers of CRT response were calculated. Segmental strains showed good to excellent agreement between SLICE and CMR-TAG (septum strain, intraclass correlation coefficient (ICC) 0.76; lateral wall strain, ICC 0.66). Conventional markers of CRT response also showed close agreement between both methods (ICC 0.61-0.78). Reproducibility of SLICE was excellent for intra-observer testing (all ICC ≥0.76) and good for interobserver testing (all ICC ≥0.61). The novel SLICE post-processing technique on standard CMR cine images offers both accurate and robust segmental strain measures compared to the 'gold standard' CMR-TAG technique, and has the advantage of being widely available. • Myocardial strain analysis could potentially improve patient selection for CRT. • Currently a well validated clinical approach to derive segmental strains is lacking. • The novel SLICE technique derives segmental strains from standard CMR cine images. • SLICE-derived strain markers of CRT response showed close agreement with CMR-TAG. • Future studies will focus on the prognostic value of SLICE in CRT candidates.

Cine magnetic resonance

International Nuclear Information System (INIS)

Higgins, C.B.; Sechtem, U.P.; Pflugfelder, P.

1987-01-01

Cine magnetic resonance (MR) is a fast MR imaging process with referencing of the imaging data to the electrocardiogram (ECG) so that images corresponding to 21-msec segments of the cardiac cycle are acquired. A series of such images, each corresponding to a 21-msec segment of the cardiac cycle, can be laced together for viewing in the cine format at a framing rate of 20 to 40 frames per second. Since cine angiograms of the heart are usually done at 30 frames per second, this technique achieves a temporal resolution adequate for the evluation of central cardiovascular function. The major application of this technique is to depict central cardiovascular function and blood flow

Benchtop phase-contrast X-ray imaging

Energy Technology Data Exchange (ETDEWEB)

Gundogdu, O. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)], E-mail: o.gundogdu@surrey.ac.uk; Nirgianaki, E.; Che Ismail, E.; Jenneson, P.M.; Bradley, D.A. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

2007-12-15

Clinical radiography has traditionally been based on contrast obtained from absorption when X-rays pass through the body. The contrast obtained from traditional radiography can be rather poor, particularly when it comes to soft tissue. A wide range of media of interest in materials science, biology and medicine exhibit very weak absorption contrast, but they nevertheless produce significant phase shifts with X-rays. The use of phase information for imaging purposes is therefore an attractive prospect. Some of the X-ray phase-contrast imaging methods require highly monochromatic plane wave radiation and sophisticated X-ray optics. However, the propagation-based phase-contrast imaging method adapted in this paper is a relatively simple method to implement, essentially requiring only a microfocal X-ray tube and electronic detection. In this paper, we present imaging results obtained from two different benchtop X-ray sources employing the free space propagation method. X-ray phase-contrast imaging provides higher contrast in many samples, including biological tissues that have negligible absorption contrast.

Cine MRI of patients with cervical myelopathy

International Nuclear Information System (INIS)

Ukita, Yasutaka

1993-01-01

Forty-six patients with cervical myelopathy were examined before and after surgery by cine magnetic resonance imaging (MRI). According to the occurrence site and degree of flow void, cerebrospinal fluid (CSF) flow void was classified into five: anterior type (flow void mainly in the anterior part of subarachnoid space), posterior type (mainly in the posteiror part), anteroposterior type (in the anterior and posterior parts), incomplete block type (flow void limited to the upper and lower parts of the block), and complete block type (no flow void). None of the 46 patients had normal CSF flow void on cine MRI before surgery. CSF flow void was seen in systolic phase on ECG (from 150 to 300 msec from R's wave) in all patients after spinal cord decompression. Postoperative CBF flow void types correlated well with surgical method, disease, and postoperative vertebral alignment. Postoperative outcome was the most excellent in the group of posterior type and the poorest in the group of anteroposterior type, showing a significant difference between the groups. Cine MRI is a useful noninvasive, dynamic method for assessing postoperative decompression effect. (N.K.)

Isotropic 3D cardiac cine MRI allows efficient sparse segmentation strategies based on 3D surface reconstruction.

Science.gov (United States)

Odille, Freddy; Bustin, Aurélien; Liu, Shufang; Chen, Bailiang; Vuissoz, Pierre-André; Felblinger, Jacques; Bonnemains, Laurent

2018-05-01

Segmentation of cardiac cine MRI data is routinely used for the volumetric analysis of cardiac function. Conventionally, 2D contours are drawn on short-axis (SAX) image stacks with relatively thick slices (typically 8 mm). Here, an acquisition/reconstruction strategy is used for obtaining isotropic 3D cine datasets; reformatted slices are then used to optimize the manual segmentation workflow. Isotropic 3D cine datasets were obtained from multiple 2D cine stacks (acquired during free-breathing in SAX and long-axis (LAX) orientations) using nonrigid motion correction (cine-GRICS method) and super-resolution. Several manual segmentation strategies were then compared, including conventional SAX segmentation, LAX segmentation in three views only, and combinations of SAX and LAX slices. An implicit B-spline surface reconstruction algorithm is proposed to reconstruct the left ventricular cavity surface from the sparse set of 2D contours. All tested sparse segmentation strategies were in good agreement, with Dice scores above 0.9 despite using fewer slices (3-6 sparse slices instead of 8-10 contiguous SAX slices). When compared to independent phase-contrast flow measurements, stroke volumes computed from four or six sparse slices had slightly higher precision than conventional SAX segmentation (error standard deviation of 5.4 mL against 6.1 mL) at the cost of slightly lower accuracy (bias of -1.2 mL against 0.2 mL). Functional parameters also showed a trend to improved precision, including end-diastolic volumes, end-systolic volumes, and ejection fractions). The postprocessing workflow of 3D isotropic cardiac imaging strategies can be optimized using sparse segmentation and 3D surface reconstruction. Magn Reson Med 79:2665-2675, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Free-breathing cine CT for the diagnosis of tracheomalacia in young children

International Nuclear Information System (INIS)

Goo, Hyun Woo

2013-01-01

Tracheomalacia is characterized by excessive expiratory collapse of the trachea. To investigate the accuracy of free-breathing cine CT for diagnosis of tracheomalacia in young children with bronchoscopy as reference standard. In a retrospective study (May 2001-July 2008), a patient group (n = 27) of children with bronchoscopic evidence of tracheomalacia, and a control group (n = 320) underwent free-breathing cine CT. The tracheal shape on free-breathing cine CT was classified as round, lunate, elongated or crescentic. Cross-sectional area change of the trachea and age were compared between the groups and the diagnostic performance of free-breathing cine CT for tracheomalacia was evaluated. The patient group showed significantly greater cross-sectional area change of the trachea (57.2% ± 22.2% vs. 10.6% ± 11.2%, P < 0.001) than the control group. If a cross-sectional area change of the trachea of 31.6% was used as a cut-off value for the diagnosis of tracheomalacia, the sensitivity, specificity and accuracy of cine CT were 96.3% (26/27), 97.2% (311/320) and 97.1% (337/347), respectively. If a crescentic shape during the expiratory phase was used, the sensitivity, specificity and accuracy were 51.9% (14/27), 98.8% (316/320) and 95.1% (330/347), respectively. Free-breathing cine CT has potential to provide the diagnosis of tracheomalacia in young children. (orig.)

Contrast-enhanced magnetic resonance angiography of persistent fifth aortic arch in children

International Nuclear Information System (INIS)

Zhong, Yumin; Zhu, Ming; Sun, Aimin; Li, Yuhua; Jaffe, Richard B.; Gao, Wei

2007-01-01

Cine angiography and echocardiography have been utilized to diagnose congenital aortic arch anomalies. However, the visualization of great vessels by echocardiography is limited, while cine angiography requires cardiac catheterization with ionizing radiation. Contrast-enhanced magnetic resonance angiography (MRA) is a noninvasive modality suitable for visualization of congenital aortic arch anomalies. To evaluate the utility of contrast-enhanced MRA in the diagnosis of persistent fifth aortic arch, a rare congenital aortic arch anomaly, and to compare the diagnostic accuracy of MRA with that of echocardiography and cine angiography. In four pediatric patients, contrast-enhanced MRA studies were performed for diagnosing persistent fifth aortic arch. The findings of MRA were compared with echocardiographic findings and confirmed by cine angiography and operation. Transthoracic surface echocardiography noted an aberrant vessel arising from the ascending aorta in two of four patients; the etiology of this vessel was uncertain. In the other two patients a diagnosis of coarctation was made. Of the four patients, only one was diagnosed with interruption of the aortic arch. Contrast-enhanced MRA clarified uncertain echocardiographic findings, enabling the correct diagnosis of persistent fifth aortic arch with fourth aortic arch interruption in all four patients. Contrast-enhanced MRA is a safe, accurate, and fast imaging technique for the evaluation of persistent fifth aortic arch and may obviate the need for conventional cine angiography. Cardiac catheterization may be reserved for some types of complicated congenital heart disease and for obtaining hemodynamic information. (orig.)

Compressive Phase Contrast Tomography

International Nuclear Information System (INIS)

Maia, Filipe; MacDowell, Alastair; Marchesini, Stefano; Padmore, Howard A.; Parkinson, Dula Y.; Pien, Jack; Schirotzek, Andre; Yang, Chao

2010-01-01

When x-rays penetrate soft matter, their phase changes more rapidly than their amplitude. Interference effects visible with high brightness sources creates higher contrast, edge enhanced images. When the object is piecewise smooth (made of big blocks of a few components), such higher contrast datasets have a sparse solution. We apply basis pursuit solvers to improve SNR, remove ring artifacts, reduce the number of views and radiation dose from phase contrast datasets collected at the Hard X-Ray Micro Tomography Beamline at the Advanced Light Source. We report a GPU code for the most computationally intensive task, the gridding and inverse gridding algorithm (non uniform sampled Fourier transform).

Phase-contrast X-ray CT

Energy Technology Data Exchange (ETDEWEB)

Momose, Atsushi [Hitachi Ltd., Saitama (Japan). Advanced Research Laboratory; Takeda, Tohoru; Itai, Yuji

1995-12-01

Phase-contrast X-ray computed tomography (CT) enabling the observation of biological soft tissues without contrast enhancement has been developed. The X-ray phase shift caused by an object is measured and input to a standard CT reconstruction algorithm. A thousand times increase in the image sensitivity to soft tissues is achieved compared with the conventional CT using absorption contrast. This is because the X-ray phase shift cross section of light elements is about a thousand times larger than the absorption cross section. The phase shift is detected using an X-ray interferometer and computer analyses of interference patterns. Experiments were performed using a synchrotron X-ray source. Excellent image sensitivity is demonstrated in the observation of cancerous rabbit liver. The CT images distinguish cancer lesion from normal liver tissue and, moreover, visualize the pathological condition in the lesion. Although the X-ray energy employed and the present observation area size are not suitable for medical applications as they are, phase-contrast X-ray CT is promising for investigating the internal structure of soft tissue which is almost transparent for X-rays. The high sensitivity also provides the advantage of reducing X-ray doses. (author).

Dose calculation with respiration-averaged CT processed from cine CT without a respiratory surrogate

International Nuclear Information System (INIS)

Riegel, Adam C.; Ahmad, Moiz; Sun Xiaojun; Pan Tinsu

2008-01-01

Dose calculation for thoracic radiotherapy is commonly performed on a free-breathing helical CT despite artifacts caused by respiratory motion. Four-dimensional computed tomography (4D-CT) is one method to incorporate motion information into the treatment planning process. Some centers now use the respiration-averaged CT (RACT), the pixel-by-pixel average of the ten phases of 4D-CT, for dose calculation. This method, while sparing the tedious task of 4D dose calculation, still requires 4D-CT technology. The authors have recently developed a means to reconstruct RACT directly from unsorted cine CT data from which 4D-CT is formed, bypassing the need for a respiratory surrogate. Using RACT from cine CT for dose calculation may be a means to incorporate motion information into dose calculation without performing 4D-CT. The purpose of this study was to determine if RACT from cine CT can be substituted for RACT from 4D-CT for the purposes of dose calculation, and if increasing the cine duration can decrease differences between the dose distributions. Cine CT data and corresponding 4D-CT simulations for 23 patients with at least two breathing cycles per cine duration were retrieved. RACT was generated four ways: First from ten phases of 4D-CT, second, from 1 breathing cycle of images, third, from 1.5 breathing cycles of images, and fourth, from 2 breathing cycles of images. The clinical treatment plan was transferred to each RACT and dose was recalculated. Dose planes were exported at orthogonal planes through the isocenter (coronal, sagittal, and transverse orientations). The resulting dose distributions were compared using the gamma (γ) index within the planning target volume (PTV). Failure criteria were set to 2%/1 mm. A follow-up study with 50 additional lung cancer patients was performed to increase sample size. The same dose recalculation and analysis was performed. In the primary patient group, 22 of 23 patients had 100% of points within the PTV pass γ criteria

Cardiac cine MRI: Comparison of 1.5 T, non-enhanced 3.0 T and blood pool enhanced 3.0 T imaging

International Nuclear Information System (INIS)

Gerretsen, S.C.; Versluis, B.; Bekkers, S.C.A.M.; Leiner, T.

2008-01-01

Introduction: Cardiac cine imaging using balanced steady state free precession sequences (bSSFP) suffers from artefacts at 3.0 T. We compared bSSFP cardiac cine imaging at 1.5 T with gradient echo imaging at 3.0 T with and without a blood pool contrast agent. Materials and methods: Eleven patients referred for cardiac cine imaging underwent imaging at 1.5 T and 3.0 T. At 3.0 T images were acquired before and after administration of 0.03 mmol/kg gadofosveset. Blood pool signal-to-noise ratio (SNR), temporal variations in SNR, ejection fraction and myocardial mass were compared. Subjective image quality was scored on a four-point scale. Results: Blood pool SNR increased with more than 75% at 3.0 T compared to 1.5 T (p < 0.001); after contrast administration at 3.0 T SNR increased with 139% (p < 0.001). However, variations in blood pool SNR at 3.0 T were nearly three times as high versus those at 1.5 T in the absence of contrast medium (p < 0.001); after contrast administration this was reduced to approximately a factor 1.4 (p = 0.21). Saturation artefacts led to significant overestimation of ejection fraction in the absence of contrast administration (1.5 T: 44.7 ± 3.1 vs. 3.0 T: 50.7 ± 4.2 [p = 0.04] vs. 3.0 T post contrast: 43.4 ± 2.9 [p = 0.55]). Subjective image quality was highest for 1.5 T (2.8 ± 0.3), and lowest for non-enhanced 3.0 T (1.7 ± 0.6; p = 0.006). Conclusions: GRE cardiac cine imaging at 3.0 T after injection of the blood pool agent gadofosveset leads to improved objective and subjective cardiac cine image quality at 3.0 T and to the same conclusions regarding cardiac ejection fraction compared to bSSFP imaging at 1.5 T

Dynamic change in size of the lateral ventricle evaluated by cine MRI

International Nuclear Information System (INIS)

Abe, Toshi

1990-01-01

CSF pulsation suggests variation in the size of the cerebral ventricle during the cardiac cycle. CINE MRI, which is a useful technique for observation of the pulsatile CSF flow, demonstrates a dynamic change in size of the lateral ventricle. CINE MRI was performed on a 0.5 tesla MR imaging system (SMT-50, SHIMADZU). Sixteen different phased images during cardiac cycle were made by a gradient acho technique (STAGE: Short Tip Angle Gradient Echo, TE=14 msec, Flip Angle=30deg). From the measurement of the lateral ventricular areas of two different phases of CINE MRI during cadiac cycle, variation rate of cerebral ventricular area (VRCVA) was calculated. Twenty-five normal volunteers (14 younger adults aged 27-44 years, 11 older adults aged 56-73 years) and six cases of marked diffuse cerebral atrophy were studied. The results included: The mean VRCVA of younger adults was 14.4% (at right body of lateral ventricle) ∼ 30.0% (at left anterior horn of lateral ventricle). The mean VRCVA of younger adults is higher than the mean VRCVA of older adults. In the cases of marked diffuse cerebral atrophy, the mean VRCVA was very lower than the mean VRCVA of older adults. VRCVA of lateral ventricle calculated from CINE MRI seemed to have a good relationship to the brain elasticity. This noninvasive method would be used as an indication of the elastic response of the ventricles and the surrounding brain. (J.P.N.)

Miércoles al cine

OpenAIRE

Aguado Franco, Juan Carlos

2014-01-01

Se analiza un caso concreto de demanda ante una iniciativa empresarial: los miércoles al cine. Se analiza un caso concreto de demanda ante una iniciativa empresarial: los miércoles al cine. Fundamentos del Análisis Económico

Cine viability magnetic resonance imaging of the heart without increased scan time.

Science.gov (United States)

Hassanein, Azza S; Khalifa, Ayman M; Ibrahim, El-Sayed H

2016-02-01

Cardiac magnetic resonance imaging (MRI) provides information about myocardial morphology, function, and viability from cine, tagged, and late gadolinium enhancement (LGE) images, respectively. While the cine and tagged images are acquired in a time-resolved fashion, the LGE images are acquired at a single timeframe. The purpose of this work is to develop a method for generating cine LGE images without additional scan time. The motion field is extracted from the tagged images, and is then used to guide the deformation of the infarcted region from the acquired LGE image at the acquired timeframe to any other timeframe. Major techniques for motion estimation, including harmonic phase (HARP) and optical flow analysis, are tested in this work for motion estimation. The proposed method is tested on numerical phantom and images from four human subjects. The generated cine LGE images showed both viability and wall motion information in the same set of images without additional scan time or image misregistration problems. The band-pass optical flow analysis resulted in the most accurate motion estimation compared to other methods, especially HARP, which fails to track points at the myocardial boundary. Infarct transmurality from the generated images showed good agreement with myocardial strain, and wall thickening showed good agreement with that measured from conventional cine images. In conclusion, the developed technique allows for generating cine LGE images that enable simultaneous display of wall motion and viability information. The generated images could be useful for estimating myocardial contractility reserve and for treatment prognosis. Copyright © 2015 Elsevier Inc. All rights reserved.

Frequency analysis of CSF flow on cine-MRI in normal pressure hydrocephalus

International Nuclear Information System (INIS)

Miyati, Tosiaki; Kasuga, Toshio; Imai, Hiroshi; Fujita, Hiroshi; Mase, Mitsuhito; Itikawa, Katuhiro

2001-01-01

To clarify the flow dynamics of intracranial cerebrospinal fluid (CSF) in normal pressure hydrocephalus (NPH), frequency analyses of CSF flow measured with an ECG-gated phase contrast cine magnetic resonance imaging (MRI) were performed. The amplitude and phase in the CSF flow spectra in the aqueduct were determined in patients with NPH after a subarachnoid hemorrhage (SAH-NPH group, n=26), an idiopathic NPH (I-NPH group, n=4), an asymptomatic ventricular dilation or a brain atrophy (VD group, n=21), and in healthy volunteers (control group, n=25). The changes of CSF flow spectra were also analyzed 5 and 15 minutes after an intravenous injection of acetazolamide. Moreover, a phase transfer function (PTF) calculated from the spectra of the driving vascular pulsation and CSF flow in the aqueduct were assessed in patients with SAH-NPH and control groups before and after acetazolamide injection. There values were compared with the pressure volume response (PVR). The amplitude of the 1st-3rd harmonics in the SAH-NPH or I-NPH group was significantly larger than in the control or VD group because of a decrease in compliance (increase in PVR). The phase of the 1st harmonic in the SAH-NPH group was significantly different from that in the control or VD group, but no difference was found between the control and VD groups. The amplitude of the 0-3rd harmonics increased, and the phase of the 1st harmonic changed in all groups after an acetazolamide injection. An evaluation of the time course of the direct current of CSF flow provided further information about the compensatory faculty of the cerebrospinal cavity. A PTF of the 1st harmonic in the SAH-NPH group was significantly larger than in the control group, and a positive correlation was noted between PTF of the 1st harmonic and PVR. In conclusion, frequency analyses of CSF flow measured by cine-MRI make it possible to obtain noninvasively a more detailed picture of the pathophysiology of NPH and of changes in intracranial

Frequency analysis of CSF flow on cine-MRI in normal pressure hydrocephalus

Energy Technology Data Exchange (ETDEWEB)

Miyati, Tosiaki; Kasuga, Toshio; Imai, Hiroshi [Kanazawa Univ. (Japan). School of Medicine; Fujita, Hiroshi; Mase, Mitsuhito; Itikawa, Katuhiro

2001-09-01

To clarify the flow dynamics of intracranial cerebrospinal fluid (CSF) in normal pressure hydrocephalus (NPH), frequency analyses of CSF flow measured with an ECG-gated phase contrast cine magnetic resonance imaging (MRI) were performed. The amplitude and phase in the CSF flow spectra in the aqueduct were determined in patients with NPH after a subarachnoid hemorrhage (SAH-NPH group, n=26), an idiopathic NPH (I-NPH group, n=4), an asymptomatic ventricular dilation or a brain atrophy (VD group, n=21), and in healthy volunteers (control group, n=25). The changes of CSF flow spectra were also analyzed 5 and 15 minutes after an intravenous injection of acetazolamide. Moreover, a phase transfer function (PTF) calculated from the spectra of the driving vascular pulsation and CSF flow in the aqueduct were assessed in patients with SAH-NPH and control groups before and after acetazolamide injection. There values were compared with the pressure volume response (PVR). The amplitude of the 1st-3rd harmonics in the SAH-NPH or I-NPH group was significantly larger than in the control or VD group because of a decrease in compliance (increase in PVR). The phase of the 1st harmonic in the SAH-NPH group was significantly different from that in the control or VD group, but no difference was found between the control and VD groups. The amplitude of the 0-3rd harmonics increased, and the phase of the 1st harmonic changed in all groups after an acetazolamide injection. An evaluation of the time course of the direct current of CSF flow provided further information about the compensatory faculty of the cerebrospinal cavity. A PTF of the 1st harmonic in the SAH-NPH group was significantly larger than in the control group, and a positive correlation was noted between PTF of the 1st harmonic and PVR. In conclusion, frequency analyses of CSF flow measured by cine-MRI make it possible to obtain noninvasively a more detailed picture of the pathophysiology of NPH and of changes in intracranial

Megavoltage conebeam CT cine as final verification of treatment plan in lung stereotactic body radiotherapy

International Nuclear Information System (INIS)

Kudithipudi, Vijay; Gayou, Olivier; Colonias, Athanasios

2016-01-01

To analyse the clinical impact of megavoltage conebeam computed tomography (MV-CBCT) cine on internal target volume (ITV) coverage in lung stereotactic body radiotherapy (SBRT). One hundred and six patients received lung SBRT. All underwent 4D computed tomography simulation followed by treatment via image guided 3D conformal or intensity modulated radiation. Prior to SBRT, all patients underwent MV-CBCT cine, in which raw projections are displayed as beam's-eye-view fluoroscopic series with the planning target volume (PTV) projected onto each image, enabling verification of tumour motion relative to the PTV and assessment of adequacy of treatment margin. Megavoltage conebeam computed tomography cine was completed 1–2 days prior to SBRT. Four patients (3.8%) had insufficient ITV coverage inferiorly at cine review. All four plans were changed by adding 5 mm on the PTV margin inferiorly. The mean change in PTV volumes was 3.9 cubic centimetres (cc) (range 1.85–6.32 cc). Repeat cine was performed after plan modification to ensure adequate PTV coverage in the modified plans. PTV margin was adequate in the majority of patients with this technique. MV-CBCT cine did show insufficient coverage in a small subset of patients. Insufficient PTV margins may be a function of 4D CT simulation inadequacies or deficiencies in visualizing the ITV inferior border in the full-inhale phase. MV-CBCT cine is a valuable tool for final verification of PTV margins.

Dobutamine cine magnetic resonance imaging after myocardial infarction; Cine Risonanza Magnetica con dobutamina dopo infarto del miocardio

Energy Technology Data Exchange (ETDEWEB)

Giovagnoni, A.; Ligabue, G.; Romagnoli, R. [Modena Univ., Modena (Italy). Scienze Radiologiche, Dipt. di Medicina Interna; Reggio Emilia Univ., Reggio Emilia (Italy). Cattedra di Cardiologia; Rossi, R.; Muia, N.; Modena, M.G. [Modena Univ., Modena (Italy). Dipt. di Scienze Mediche, Oncologiche e Radiologiche; Reggio Emilia Univ. (Italy). Dipt. di Scienze Mediche, Oncologiche e Radiologiche

1999-12-01

Dobutamine Cine MRI is a new diagnostic imaging technique in the pretreatment (revascularization) assessment of myocardial infarction patients. In this issue are reported the result of a comparative study of the diagnostic yield of dobutamine Cine MRI with that of stress echocardiography in the assessment of viable myocardium. A new method for analysis of Cine MR images, employing digital subtraction, aimed at decreasing subjectivity in the quantitative assessment of myocardial wall thickening. Twenty-six patients (21 men and 5 women) with a history of myocardial infarction who were scheduled for revascularization were submitted to stress echocardiography and dobutamine Cine MRI to evaluate contractile recovery of the segments considered akinetic or hypo kinetic at baseline echocardiography. Dobutamine was administered in growing doses (5, 10, 15{gamma}/kg/min). 16 segments of the left ventricle in each patient were considered. In the 416 segments studied, it was found that 307 normo kinetic, 64 scarred and 45 viable segments with stress echocardiography, versus 302 normo kinetic, 83 scarred and 31 viable segments with dobutamine MRI. Three months after revascularization 15 patients were examined to check contractile recovery of the segments considered as viable. Echocardiography had 79% sensitivity and 97% specificity, while Cine MRI had 96% and 86%, respectively. In patients with anteroseptal wall myocardial infarction stress echocardiography had 75% sensitivity and 97% specificity. Echocardiography permits to distinguish viable myocardium and scarred myocardial tissue with good sensitivity and specificity, but Cine MRI performs better. Cine MRI has much higher sensitivity than stress echocardiography and thus makes the technique of choice to evaluate viable myocardium in these sites. The digital subtraction technique is as accurate as manual measurements, but reduces the error rate and permits quicker evaluation, particularly in subendocardial thickening

Single breath hold 3D cardiac cine MRI using kat-ARC: preliminary results at 1.5T.

Science.gov (United States)

Jeong, Daniel; Schiebler, Mark L; Lai, Peng; Wang, Kang; Vigen, Karl K; François, Christopher J

2015-04-01

Validation of a new single breath-hold, three-dimensional, cine balanced steady-state free precession (3D cine bSSFP) cardiac magnetic resonance (CMR) sequence for left ventricular function. CMR examinations were performed on fifteen patients and three healthy volunteers on a clinical 1.5T scanner using a two-dimensional (2D) cine balanced SSFP CMR sequence (2D cine bSSFP) followed by an investigational 3D cine bSSFP pulse sequence acquired within a single breath hold. Left ventricular end diastolic volume (LVEDV), end systolic volume (LVESV), ejection fraction (LVEF), and myocardial mass were independently segmented on a workstation by two experienced radiologists. Blood pool to myocardial contrast was evaluated in consensus using a Likert scale. Bland-Altman analysis was used to compare these quantitative and nominal measurements for the two sequences. The average acquisition time was significantly shorter for the 3D cine bSSFP than for 2D cine bSSFP (0.36 ± 0.03 vs. 8.5 ± 2.3 min) p = 0.0002. Bland-Altman analyses [bias and (limits of agreement)] of the data derived from these two methods revealed that the LVEF 0.9% (-4.7, 6.4), LVEDV 4.9 ml (-23.0, 32.8), LVESV -0.2 ml (-22.4, 21.9), and myocardial mass -0.4 g (-23.8, 23.0) were not significantly different. There was excellent intraclass correlation for intra-observer variability (0.981, 0.989, 0.997, 0.985) and inter-observer variability (0.903, 0.954, 0.970, 0.842) for LVEF, LVEDV, LVESV, and myocardial mass respectively. 3D cine bSSFP allows for accurate single breath-hold volumetric cine CMR which enables substantial improvements in scanner time efficiency without sacrificing diagnostic accuracy.

Cine MR imaging of internal derangements of the knee

International Nuclear Information System (INIS)

Niitsu, M.; Anno, I.; Ishikawa, N.; Akisada, M.; Fukubayashi, T.

1990-01-01

This paper assesses internal derangements of the knee joint by a new method of cine MR imaging. Cine MR imaging, involving cine acquisition of kinematic sagittal images during knee movement, was used to evaluate 51 symptomatic patients and 19 healthy subjects. Cine MR images of cruciate ligament fears showed disappearance of low-intensity bundles during knee movement, periodic appearance of joint fluid in the area of the ligament, and irregular tibial movement. Cine MR images of meniscal tears showed independent movement of meniscal fragments and periodic tear opening and closing. Twenty-seven of the 28 anterior cruciate ligament (ACL) tears confirmed arthroscopically were correctly identified with cine MR imaging, with a sensitivity of 96% and a specificity of 92%

Three-dimensional quantification of vorticity and helicity from 3D cine PC-MRI using finite-element interpolations.

Science.gov (United States)

Sotelo, Julio; Urbina, Jesús; Valverde, Israel; Mura, Joaquín; Tejos, Cristián; Irarrazaval, Pablo; Andia, Marcelo E; Hurtado, Daniel E; Uribe, Sergio

2018-01-01

We propose a 3D finite-element method for the quantification of vorticity and helicity density from 3D cine phase-contrast (PC) MRI. By using a 3D finite-element method, we seamlessly estimate velocity gradients in 3D. The robustness and convergence were analyzed using a combined Poiseuille and Lamb-Ossen equation. A computational fluid dynamics simulation was used to compared our method with others available in the literature. Additionally, we computed 3D maps for different 3D cine PC-MRI data sets: phantom without and with coarctation (18 healthy volunteers and 3 patients). We found a good agreement between our method and both the analytical solution of the combined Poiseuille and Lamb-Ossen. The computational fluid dynamics results showed that our method outperforms current approaches to estimate vorticity and helicity values. In the in silico model, we observed that for a tetrahedral element of 2 mm of characteristic length, we underestimated the vorticity in less than 5% with respect to the analytical solution. In patients, we found higher values of helicity density in comparison to healthy volunteers, associated with vortices in the lumen of the vessels. We proposed a novel method that provides entire 3D vorticity and helicity density maps, avoiding the used of reformatted 2D planes from 3D cine PC-MRI. Magn Reson Med 79:541-553, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Improved specimen reconstruction by Hilbert phase contrast tomography.

Science.gov (United States)

Barton, Bastian; Joos, Friederike; Schröder, Rasmus R

2008-11-01

The low signal-to-noise ratio (SNR) in images of unstained specimens recorded with conventional defocus phase contrast makes it difficult to interpret 3D volumes obtained by electron tomography (ET). The high defocus applied for conventional tilt series generates some phase contrast but leads to an incomplete transfer of object information. For tomography of biological weak-phase objects, optimal image contrast and subsequently an optimized SNR are essential for the reconstruction of details such as macromolecular assemblies at molecular resolution. The problem of low contrast can be partially solved by applying a Hilbert phase plate positioned in the back focal plane (BFP) of the objective lens while recording images in Gaussian focus. Images recorded with the Hilbert phase plate provide optimized positive phase contrast at low spatial frequencies, and the contrast transfer in principle extends to the information limit of the microscope. The antisymmetric Hilbert phase contrast (HPC) can be numerically converted into isotropic contrast, which is equivalent to the contrast obtained by a Zernike phase plate. Thus, in-focus HPC provides optimal structure factor information without limiting effects of the transfer function. In this article, we present the first electron tomograms of biological specimens reconstructed from Hilbert phase plate image series. We outline the technical implementation of the phase plate and demonstrate that the technique is routinely applicable for tomography. A comparison between conventional defocus tomograms and in-focus HPC volumes shows an enhanced SNR and an improved specimen visibility for in-focus Hilbert tomography.

Dual focal-spot imaging for phase extraction in phase-contrast radiography

International Nuclear Information System (INIS)

Donnelly, Edwin F.; Price, Ronald R.; Pickens, David R.

2003-01-01

The purpose of this study was to evaluate dual focal spot imaging as a method for extracting the phase component from a phase-contrast radiography image. All measurements were performed using a microfocus tungsten-target x-ray tube with an adjustable focal-spot size (0.01 mm to 0.045 mm). For each object, high-resolution digital radiographs were obtained with two different focal spot sizes to produce matched image pairs in which all other geometric variables as well as total exposure and tube kVp were held constant. For each image pair, a phase extraction was performed using pixel-wise division. The phase-extracted image resulted in an image similar to the standard image processing tool commonly referred to as 'unsharp masking' but with the additional edge-enhancement produced by phase-contrast effects. The phase-extracted image illustrates the differences between the two images whose imaging parameters differ only in focal spot size. The resulting image shows effects from both phase contrast as well as geometric unsharpness. In weakly attenuating materials the phase-contrast effect predominates, while in strongly attenuating materials the phase effects are so small that they are not detectable. The phase-extracted image in the strongly attenuating object reflects differences in geometric unsharpness. The degree of phase extraction depends strongly on the size of the smallest focal spot used. This technique of dual-focal spot phase-contrast radiography provides a simple technique for phase-component (edge) extraction in phase-contrast radiography. In strongly attenuating materials the phase-component is overwhelmed by differences in geometric unsharpness. In these cases the technique provides a form of unsharp masking which also accentuates the edges. Thus, the two effects are complimentary and may be useful in the detection of small objects

Application of phase contrast imaging to mammography

International Nuclear Information System (INIS)

Tohyama, Keiko; Yamada, Katsuhiko; Katafuchi, Tetsuro; Matsuo, Satoru; Morishita, Junji

2005-01-01

Phase contrast images were obtained experimentally by using a customized mammography unit with a nominal focal spot size of 100 μm and variable source-to-image distances of up to 1.5 m. The purpose of this study was to examine the applicability and potential usefulness of phase contrast imaging for mammography. A mammography phantom (ACR156 RMI phantom) was imaged, and its visibility was examined. The optical density of the phantom images was adjusted to approximately 1.3 for both the contact and phase contrast images. Forty-one observers (18 medical doctors and 23 radiological technologists) participated in visual evaluation of the images. Results showed that, in comparison with the images of contact mammography, the phantom images of phase contrast imaging demonstrated statistically significantly superior visibility for fibers, clustered micro-calcifications, and masses. Therefore, phase contrast imaging obtained by using the customized mammography unit would be useful for improving diagnostic accuracy in mammography. (author)

Contrast-to-noise ratio optimization for a prototype phase-contrast computed tomography scanner

International Nuclear Information System (INIS)

Müller, Mark; Yaroshenko, Andre; Velroyen, Astrid; Tapfer, Arne; Bech, Martin; Pauwels, Bart; Bruyndonckx, Peter; Sasov, Alexander; Pfeiffer, Franz

2015-01-01

In the field of biomedical X-ray imaging, novel techniques, such as phase-contrast and dark-field imaging, have the potential to enhance the contrast and provide complementary structural information about a specimen. In this paper, a first prototype of a preclinical X-ray phase-contrast CT scanner based on a Talbot-Lau interferometer is characterized. We present a study of the contrast-to-noise ratios for attenuation and phase-contrast images acquired with the prototype scanner. The shown results are based on a series of projection images and tomographic data sets of a plastic phantom in phase and attenuation-contrast recorded with varying acquisition settings. Subsequently, the signal and noise distribution of different regions in the phantom were determined. We present a novel method for estimation of contrast-to-noise ratios for projection images based on the cylindrical geometry of the phantom. Analytical functions, representing the expected signal in phase and attenuation-contrast for a circular object, are fitted to individual line profiles of the projection data. The free parameter of the fit function is used to estimate the contrast and the goodness of the fit is determined to assess the noise in the respective signal. The results depict the dependence of the contrast-to-noise ratios on the applied source voltages, the number of steps of the phase stepping routine, and the exposure times for an individual step. Moreover, the influence of the number of projection angles on the image quality of CT slices is investigated. Finally, the implications for future imaging purposes with the scanner are discussed

Biological applications of phase-contrast electron microscopy.

Science.gov (United States)

Nagayama, Kuniaki

2014-01-01

Here, I review the principles and applications of phase-contrast electron microscopy using phase plates. First, I develop the principle of phase contrast based on a minimal model of microscopy, introducing a double Fourier-transform process to mathematically formulate the image formation. Next, I explain four phase-contrast (PC) schemes, defocus PC, Zernike PC, Hilbert differential contrast, and schlieren optics, as image-filtering processes in the context of the minimal model, with particular emphases on the Zernike PC and corresponding Zernike phase plates. Finally, I review applications of Zernike PC cryo-electron microscopy to biological systems such as protein molecules, virus particles, and cells, including single-particle analysis to delineate three-dimensional (3D) structures of protein and virus particles and cryo-electron tomography to reconstruct 3D images of complex protein systems and cells.

Functional imaging of murine hearts using accelerated self-gated UTE cine MRI.

Science.gov (United States)

Motaal, Abdallah G; Noorman, Nils; de Graaf, Wolter L; Hoerr, Verena; Florack, Luc M J; Nicolay, Klaas; Strijkers, Gustav J

2015-01-01

We introduce a fast protocol for ultra-short echo time (UTE) Cine magnetic resonance imaging (MRI) of the beating murine heart. The sequence involves a self-gated UTE with golden-angle radial acquisition and compressed sensing reconstruction. The self-gated acquisition is performed asynchronously with the heartbeat, resulting in a randomly undersampled kt-space that facilitates compressed sensing reconstruction. The sequence was tested in 4 healthy rats and 4 rats with chronic myocardial infarction, approximately 2 months after surgery. As a control, a non-accelerated self-gated multi-slice FLASH sequence with an echo time (TE) of 2.76 ms, 4.5 signal averages, a matrix of 192 × 192, and an acquisition time of 2 min 34 s per slice was used to obtain Cine MRI with 15 frames per heartbeat. Non-accelerated UTE MRI was performed with TE = 0.29 ms, a reconstruction matrix of 192 × 192, and an acquisition time of 3 min 47 s per slice for 3.5 averages. Accelerated imaging with 2×, 4× and 5× undersampled kt-space data was performed with 1 min, 30 and 15 s acquisitions, respectively. UTE Cine images up to 5× undersampled kt-space data could be successfully reconstructed using a compressed sensing algorithm. In contrast to the FLASH Cine images, flow artifacts in the UTE images were nearly absent due to the short echo time, simplifying segmentation of the left ventricular (LV) lumen. LV functional parameters derived from the control and the accelerated Cine movies were statistically identical.

Phase Contrast Imaging

DEFF Research Database (Denmark)

1996-01-01

The invention relates to a method and a system for synthesizing a prescribed intensity pattern based on phase contrast imaging that is not based on the assumption of prior art methods that the pahase shift phi is less than 1 radian. An improved method based on a simple imaging operation...... phasors attain predetermined values for predetermined spatial frequencies, and the phasor value of the specific resolution element of the spatial phase mask corresponds to a distinct intensity level of the image of the resolution element in the intensity pattern, and a spatial phase filter for phase...... shifting of a part of the electromagntic radiation, in combination with an imaging system for generation of the intensity pattern by interference in the image plane of the imaging system between the part of the electromagnetic raidation that has been phase shifted by the phase filter and the remaining part...

Evaluation of highly accelerated real-time cardiac cine MRI in tachycardia.

Science.gov (United States)

Bassett, Elwin C; Kholmovski, Eugene G; Wilson, Brent D; DiBella, Edward V R; Dosdall, Derek J; Ranjan, Ravi; McGann, Christopher J; Kim, Daniel

2014-02-01

Electrocardiogram (ECG)-gated breath-hold cine MRI is considered to be the gold standard test for the assessment of cardiac function. However, it may fail in patients with arrhythmia, impaired breath-hold capacity and poor ECG gating. Although ungated real-time cine MRI may mitigate these problems, commercially available real-time cine MRI pulse sequences using parallel imaging typically yield relatively poor spatiotemporal resolution because of their low image acquisition efficiency. As an extension of our previous work, the purpose of this study was to evaluate the diagnostic quality and accuracy of eight-fold-accelerated real-time cine MRI with compressed sensing (CS) for the quantification of cardiac function in tachycardia, where it is challenging for real-time cine MRI to provide sufficient spatiotemporal resolution. We evaluated the performances of eight-fold-accelerated cine MRI with CS, three-fold-accelerated real-time cine MRI with temporal generalized autocalibrating partially parallel acquisitions (TGRAPPA) and ECG-gated breath-hold cine MRI in 21 large animals with tachycardia (mean heart rate, 104 beats per minute) at 3T. For each cine MRI method, two expert readers evaluated the diagnostic quality in four categories (image quality, temporal fidelity of wall motion, artifacts and apparent noise) using a Likert scale (1-5, worst to best). One reader evaluated the left ventricular functional parameters. The diagnostic quality scores were significantly different between the three cine pulse sequences, except for the artifact level between CS and TGRAPPA real-time cine MRI. Both ECG-gated breath-hold cine MRI and eight-fold accelerated real-time cine MRI yielded all four scores of ≥ 3.0 (acceptable), whereas three-fold-accelerated real-time cine MRI yielded all scores below 3.0, except for artifact (3.0). The left ventricular ejection fraction (LVEF) measurements agreed better between ECG-gated cine MRI and eight-fold-accelerated real-time cine MRI

Megavoltage conebeam CT cine as final verification of treatment plan in lung stereotactic body radiotherapy.

Science.gov (United States)

Kudithipudi, Vijay; Gayou, Olivier; Colonias, Athanasios

2016-06-01

To analyse the clinical impact of megavoltage conebeam computed tomography (MV-CBCT) cine on internal target volume (ITV) coverage in lung stereotactic body radiotherapy (SBRT). One hundred and six patients received lung SBRT. All underwent 4D computed tomography simulation followed by treatment via image guided 3D conformal or intensity modulated radiation. Prior to SBRT, all patients underwent MV-CBCT cine, in which raw projections are displayed as beam's-eye-view fluoroscopic series with the planning target volume (PTV) projected onto each image, enabling verification of tumour motion relative to the PTV and assessment of adequacy of treatment margin. Megavoltage conebeam computed tomography cine was completed 1-2 days prior to SBRT. Four patients (3.8%) had insufficient ITV coverage inferiorly at cine review. All four plans were changed by adding 5 mm on the PTV margin inferiorly. The mean change in PTV volumes was 3.9 cubic centimetres (cc) (range 1.85-6.32 cc). Repeat cine was performed after plan modification to ensure adequate PTV coverage in the modified plans. PTV margin was adequate in the majority of patients with this technique. MV-CBCT cine did show insufficient coverage in a small subset of patients. Insufficient PTV margins may be a function of 4D CT simulation inadequacies or deficiencies in visualizing the ITV inferior border in the full-inhale phase. MV-CBCT cine is a valuable tool for final verification of PTV margins. © 2016 The Royal Australian and New Zealand College of Radiologists.

X-ray phase-contrast imaging

Science.gov (United States)

Endrizzi, Marco

2018-01-01

X-ray imaging is a standard tool for the non-destructive inspection of the internal structure of samples. It finds application in a vast diversity of fields: medicine, biology, many engineering disciplines, palaeontology and earth sciences are just few examples. The fundamental principle underpinning the image formation have remained the same for over a century: the X-rays traversing the sample are subjected to different amount of absorption in different parts of the sample. By means of phase-sensitive techniques it is possible to generate contrast also in relation to the phase shifts imparted by the sample and to extend the capabilities of X-ray imaging to those details that lack enough absorption contrast to be visualised in conventional radiography. A general overview of X-ray phase contrast imaging techniques is presented in this review, along with more recent advances in this fast evolving field and some examples of applications.

Phase-contrast MR assessment of pulmonary venous blood flow in children with surgically repaired pulmonary veins

International Nuclear Information System (INIS)

Valsangiacomo, Emanuela R.; Yoo, Shi-Joon; Barrea, Catherine; Smallhorn, Jeffrey F.; Macgowan, Christopher K.; Coles, John G.

2003-01-01

Pulmonary venous (PV) obstruction may complicate surgical repair of PV abnormalities. By combining phase-contrast cine (PC) imaging and contrast-enhanced angiography, magnetic resonance (MR) imaging can provide physiological information complementing anatomical diagnosis. To compare the PV flow pattern observed after surgical repair of PV abnormalities with normal PV flow pattern and to investigate the changes occurring in the presence of PV stenosis by using PC MR in children. By using PC MR, PV flow was evaluated in 14 patients (3 months-14 years) who underwent surgical repair for PV abnormalities. Eleven children (8-18 years) were studied as normal controls. Peak flow velocities and patterns were compared among three groups: normal veins (n=23), surgically repaired veins without (n=44) and with stenosis (n=10). Normal and unobstructed pulmonary veins after surgery showed a biphasic or triphasic flow pattern with one or two systolic peaks and a diastolic peak. Unobstructed surgically repaired veins showed decreased peak systolic velocity (P =0.001) and an increased peak diastolic velocity (P=0.005) when compared to normal values. Obstructed veins showed decreased systolic and diastolic velocities when measured upstream from the stenosis. PC MR shows different flow patterns among normal, surgically repaired pulmonary veins with and without stenosis. (orig.)

The Cine Club de Lima

Directory of Open Access Journals (Sweden)

Ricardo Bedoya

2009-10-01

Full Text Available Cine Club de Lima was the most important cinematography culture spreading institution of the fifties. It was also the precursor of other movie clubs of following decades, which would bring together important Peruvian intellectuals from every art form, who would together promote cultural entertainment. This piece describes ”Cine Club Lima” origins and dissolution, while taking into account its programs.

El cine como golosina. Reflexiones sobre el consumo de cine en los jóvenes

Directory of Open Access Journals (Sweden)

Jerónimo León Rivera-Betancur

2008-01-01

Full Text Available Este texto parte de los resultados de una investigación realizada en Medellín en 2005 a fi n de hacer una reflexión más amplia alrededor del tema del consumo de cine. El artículo cuestiona la estrecha relación entre oferta y demanda del cine en Colombia, y algunas características comunes a los espectadores que se acercan a las salas buscando estímulos audiovisuales. Factores como los hábitos de consumo, la alimentación y su relación con el cine, y las diferencias fundamentales entre lectura y consumo son algunos de los temas que se abordan en esta reflexión.

Quantification of Esophageal Tumor Motion on Cine-Magnetic Resonance Imaging

Energy Technology Data Exchange (ETDEWEB)

Lever, Frederiek M.; Lips, Irene M.; Crijns, Sjoerd P.M.; Reerink, Onne; Lier, Astrid L.H.M.W. van; Moerland, Marinus A.; Vulpen, Marco van; Meijer, Gert J., E-mail: g.j.meijer@umcutrecht.nl

2014-02-01

Purpose: To quantify the movement of esophageal tumors noninvasively on cine-magnetic resonance imaging (MRI) by use of a semiautomatic method to visualize tumor movement directly throughout multiple breathing cycles. Methods and Materials: Thirty-six patients with esophageal tumors underwent MRI. Tumors were located in the upper (8), middle (7), and lower (21) esophagus. Cine-MR images were collected in the coronal and sagittal plane during 60 seconds at a rate of 2 Hz. An adaptive correlation filter was used to automatically track a previously marked reference point. Tumor movement was measured in the craniocaudal (CC), left–right (LR), and anteroposterior (AP) directions and its relationship along the longitudinal axis of the esophagus was investigated. Results: Tumor registration within the individual images was typically done at a millisecond time scale. The mean (SD) peak-to-peak displacements in the CC, AP, and LR directions were 13.3 (5.2) mm, 4.9 (2.5) mm, and 2.7 (1.2) mm, respectively. The bandwidth to cover 95% of excursions from the mean position (c95) was also calculated to exclude outliers caused by sporadic movements. The mean (SD) c95 values were 10.1 (3.8) mm, 3.7 (1.9) mm, and 2.0 (0.9) mm in the CC, AP, and LR dimensions. The end-exhale phase provided a stable position in the respiratory cycle, compared with more variety in the end-inhale phase. Furthermore, lower tumors showed more movement than did higher tumors in the CC and AP directions. Conclusions: Intrafraction tumor movement was highly variable between patients. Tumor position proved the most stable during the respiratory cycle in the end-exhale phase. A better understanding of tumor motion makes it possible to individualize radiation delivery strategies accordingly. Cine-MRI is a successful noninvasive modality to analyze motion for this purpose in the future.

Quantification of Esophageal Tumor Motion on Cine-Magnetic Resonance Imaging

International Nuclear Information System (INIS)

Lever, Frederiek M.; Lips, Irene M.; Crijns, Sjoerd P.M.; Reerink, Onne; Lier, Astrid L.H.M.W. van; Moerland, Marinus A.; Vulpen, Marco van; Meijer, Gert J.

2014-01-01

Purpose: To quantify the movement of esophageal tumors noninvasively on cine-magnetic resonance imaging (MRI) by use of a semiautomatic method to visualize tumor movement directly throughout multiple breathing cycles. Methods and Materials: Thirty-six patients with esophageal tumors underwent MRI. Tumors were located in the upper (8), middle (7), and lower (21) esophagus. Cine-MR images were collected in the coronal and sagittal plane during 60 seconds at a rate of 2 Hz. An adaptive correlation filter was used to automatically track a previously marked reference point. Tumor movement was measured in the craniocaudal (CC), left–right (LR), and anteroposterior (AP) directions and its relationship along the longitudinal axis of the esophagus was investigated. Results: Tumor registration within the individual images was typically done at a millisecond time scale. The mean (SD) peak-to-peak displacements in the CC, AP, and LR directions were 13.3 (5.2) mm, 4.9 (2.5) mm, and 2.7 (1.2) mm, respectively. The bandwidth to cover 95% of excursions from the mean position (c95) was also calculated to exclude outliers caused by sporadic movements. The mean (SD) c95 values were 10.1 (3.8) mm, 3.7 (1.9) mm, and 2.0 (0.9) mm in the CC, AP, and LR dimensions. The end-exhale phase provided a stable position in the respiratory cycle, compared with more variety in the end-inhale phase. Furthermore, lower tumors showed more movement than did higher tumors in the CC and AP directions. Conclusions: Intrafraction tumor movement was highly variable between patients. Tumor position proved the most stable during the respiratory cycle in the end-exhale phase. A better understanding of tumor motion makes it possible to individualize radiation delivery strategies accordingly. Cine-MRI is a successful noninvasive modality to analyze motion for this purpose in the future

Laser projection using generalized phase contrast

DEFF Research Database (Denmark)

Glückstad, Jesper; Palima, Darwin; Rodrigo, Peter John

2007-01-01

is introduced. An arbitrary phase shift filter eliminates the need for high-frequency modulation and conjugate phase encoding. This lowers device performance requirements and allows practical implementation with currently available dynamic spatial light modulators. (c) 2007 Optical Society of America.......We demonstrate experimental laser projection of a gray-level photographic image with 74% light efficiency using the generalized phase contrast (GPC) method. In contrast with a previously proposed technique [Alonzo et al., New J. Phys. 9, 132 (2007)], a new approach to image construction via GPC...

Cine y literatura: narrativa de la identidad

OpenAIRE

Román, Alejandra Laverde; Parra, Martha Ligia

2010-01-01

Este artículo es resultado de la investigación La narrativa literaria y audiovisual enla construcción de la identidad cultural colombiana. Una mirada desde el cine y laliteratura: adaptaciones de obras literarias llevadas al cine entre 1920 y 2008-1.En el presente texto se desarrolla un análisis de la relación de cine y literatura enla construcción de la identidad colombiana, a partir del rastreo bibliográfico de lacrítica y las historias literarias y cinematográficas a un corpus seleccionado...

Cine MR imaging in valvular heart disease

Energy Technology Data Exchange (ETDEWEB)

Nishimura, Tsunehiko; Yamada, Naoaki; Itoh, Akira; Miyatake, Kunio

1989-01-01

Cine MR Imaging was carried out using FLASH (fast low angle shot) which employes TE of 16 msec and TR of 30/similar to/40 msec. Regurgitant jet was visible as discrete area of low signal intensity extending from the incompetent valve into the respective cardiac chamber. In 20 patients with mitral regurgitation, the correlation of the length and area of mitral jet by cine MR and color doppler mapping was 0.74 and 0.71, respectively. Cine MR imaging is a promising modality for detection and quantification of valvular heart disease.

Cine MRI: a new approach to the diagnosis of scapholunate dissociation.

Science.gov (United States)

Langner, I; Fischer, S; Eisenschenk, A; Langner, S

2015-08-01

To evaluate the feasibility of cine MRI for the detection of scapholunate dissociation (SLD) and to compare the sensitivity and specificity of cine MRI with those of cineradiography and arthroscopy. To evaluate feasibility, healthy subjects underwent cine MRI of the wrist. To evaluate sensitivity and specificity, patients with clinically suspected scapholunate ligament (SLL) injury after trauma to the wrist were prospectively included and underwent radiographic examination, cineradiography, and cine MRI. In 25 out of 38 patients, subsequent arthroscopy was performed. Results of cineradiography and cine MRI correlated with those of arthroscopy. Cine MRI was of diagnostic quality in all healthy subjects and patients with good interrater agreement. There was excellent correlation between cineradiography and cine MRI. Scapholunate distance differed significantly between healthy subjects and patients with scapholunate dissociation (p Cine MRI had 85% sensitivity and 90% specificity for the detection of SLD. Cine MRI of the wrist is a fast and reliable technique for the detection of SLD with diagnostic accuracy comparable to cineradiography. It can be easily implemented as a routine clinical MRI examination, facilitating diagnostic workup of patients with suspected SLD while avoiding radiation exposure.

Cine MRI: a new approach to the diagnosis of scapholunate dissociation

Energy Technology Data Exchange (ETDEWEB)

Langner, I.; Eisenschenk, A. [University Medicine Greifswald, Division of Hand Surgery and Functional Microsurgery, Department of Trauma and Reconstructive Surgery, Greifswald (Germany); Fischer, S.; Langner, S. [University Medicine Greifswald, Institute for Diagnostic Radiology and Neuroradiology, Greifswald (Germany)

2015-08-15

To evaluate the feasibility of cine MRI for the detection of scapholunate dissociation (SLD) and to compare the sensitivity and specificity of cine MRI with those of cineradiography and arthroscopy. To evaluate feasibility, healthy subjects underwent cine MRI of the wrist. To evaluate sensitivity and specificity, patients with clinically suspected scapholunate ligament (SLL) injury after trauma to the wrist were prospectively included and underwent radiographic examination, cineradiography, and cine MRI. In 25 out of 38 patients, subsequent arthroscopy was performed. Results of cineradiography and cine MRI correlated with those of arthroscopy. Cine MRI was of diagnostic quality in all healthy subjects and patients with good interrater agreement. There was excellent correlation between cineradiography and cine MRI. Scapholunate distance differed significantly between healthy subjects and patients with scapholunate dissociation (p < 0.001), but not between imaging modalities in the patient group. Cine MRI had 85 % sensitivity and 90 % specificity for the detection of SLD. Cine MRI of the wrist is a fast and reliable technique for the detection of SLD with diagnostic accuracy comparable to cineradiography. It can be easily implemented as a routine clinical MRI examination, facilitating diagnostic workup of patients with suspected SLD while avoiding radiation exposure. (orig.)

Cardiac cine imaging at 3 Tesla: initial experience with a 32-element body-array coil.

Science.gov (United States)

Fenchel, Michael; Deshpande, Vibhas S; Nael, Kambiz; Finn, J Paul; Miller, Stephan; Ruehm, Stefan; Laub, Gerhard

2006-08-01

We sought to assess the feasibility of cardiac cine imaging and evaluate image quality at 3 T using a body-array coil with 32 coil elements. Eight healthy volunteers (3 men; median age 29 years) were examined on a 3-T magnetic resonance scanner (Magnetom Trio, Siemens Medical Solutions) using a 32-element phased-array coil (prototype from In vivo Corp.). Gradient-recalled-echo (GRE) cine (GRAPPAx3), GRE cine with tagging lines, steady-state-free-precession (SSFP) cine (GRAPPAx3 and x4), and SSFP cine(TSENSEx4 andx6) images were acquired in short-axis and 4-chamber view. Reference images with identical scan parameters were acquired using the total-imaging-matrix (Tim) coil system with a total of 12 coil elements. Images were assessed by 2 observers in a consensus reading with regard to image quality, noise and presence of artifacts. Furthermore, signal-to-noise values were determined in phantom measurements. In phantom measurements signal-to-noise values were increased by 115-155% for the various cine sequences using the 32-element coil. Scoring of image quality yielded statistically significant increased image quality with the SSFP-GRAPPAx4, SSFP-TSENSEx4, and SSFP-TSENSEx6 sequence using the 32-element coil (P < 0.05). Similarly, scoring of image noise yielded a statistically significant lower noise rating with the SSFP-GRAPPAx4, GRE-GRAPPAx3, SSFP-TSENSEx4, and SSFP-TSENSEx6 sequence using the 32-element coil (P < 0.05). This study shows that cardiac cine imaging at 3 T using a 32-element body-array coil is feasible in healthy volunteers. Using a large number of coil elements with a favorable sensitivity profile supports faster image acquisition, with high diagnostic image quality even for high parallel imaging factors.

Cine Computed Tomography Without Respiratory Surrogate in Planning Stereotactic Radiotherapy for Non-Small-Cell Lung Cancer

International Nuclear Information System (INIS)

Riegel, Adam C. B.A.; Chang, Joe Y.; Vedam, Sastry S.; Johnson, Valen; Chi, Pai-Chun Melinda; Pan, Tinsu

2009-01-01

Purpose: To determine whether cine computed tomography (CT) can serve as an alternative to four-dimensional (4D)-CT by providing tumor motion information and producing equivalent target volumes when used to contour in radiotherapy planning without a respiratory surrogate. Methods and Materials: Cine CT images from a commercial CT scanner were used to form maximum intensity projection and respiratory-averaged CT image sets. These image sets then were used together to define the targets for radiotherapy. Phantoms oscillating under irregular motion were used to assess the differences between contouring using cine CT and 4D-CT. We also retrospectively reviewed the image sets for 26 patients (27 lesions) at our institution who had undergone stereotactic radiotherapy for Stage I non-small-cell lung cancer. The patients were included if the tumor motion was >1 cm. The lesions were first contoured using maximum intensity projection and respiratory-averaged CT image sets processed from cine CT and then with 4D-CT maximum intensity projection and 10-phase image sets. The mean ratios of the volume magnitude were compared with intraobserver variation, the mean centroid shifts were calculated, and the volume overlap was assessed with the normalized Dice similarity coefficient index. Results: The phantom studies demonstrated that cine CT captured a greater extent of irregular tumor motion than did 4D-CT, producing a larger tumor volume. The patient studies demonstrated that the gross tumor defined using cine CT imaging was similar to, or slightly larger than, that defined using 4D-CT. Conclusion: The results of our study have shown that cine CT is a promising alternative to 4D-CT for stereotactic radiotherapy planning

Cine e identidades virtuales

Directory of Open Access Journals (Sweden)

Labrador Ben, Julia María

2006-12-01

Full Text Available The subject is the ability the cinema has performed - since its very begining - as a creation instrument of national and transnational identities. In the first place, it covers Spanish cinema since 1938 and right after the end of the Spanish Civil War, II World War Italian-German cinema, Eisenstein’s, Leni Riefenstahl’s, Griffth’s and Ford’s cinema, the role American war and science fiction productions played, as well as the comedies dealing with the divided Berlin subject. The role of computers and video-games and the new cinema positionings that forecast the end of what is real, is studied through films such as Tron, The Lawnmower Man, Johnny Mnemonic, Ghost in the shell, Simone o Matrix.Se estudia la capacidad del cine desde sus orígenes como instrumento de generación de identidades nacionales y transnacionales. Se realiza, en primer lugar, un recorrido por el cine español desde 1938 y tras el final de la guerra civil, el cine italo-alemán de la II Guerra Mundial, el cine de Eisenstein, Leni Riefenstahl, Griffth y Ford, y el papel que jugaron las producciones norteamericanas bélicas y de ciencia ficción, así como las comedias sobre el Berlín dividido. El papel de los ordenadores y los videojuegos, y los nuevos planteamientos cinematográficos que pronostican el final de lo real se estudia a través de películas como Tron, El cortador de césped, Johnny Mnemonic, Ghost in the shell, Simone o Matrix.

Phase contrast STEM for thin samples: Integrated differential phase contrast.

Science.gov (United States)

Lazić, Ivan; Bosch, Eric G T; Lazar, Sorin

2016-01-01

It has been known since the 1970s that the movement of the center of mass (COM) of a convergent beam electron diffraction (CBED) pattern is linearly related to the (projected) electrical field in the sample. We re-derive a contrast transfer function (CTF) for a scanning transmission electron microscopy (STEM) imaging technique based on this movement from the point of view of image formation and continue by performing a two-dimensional integration on the two images based on the two components of the COM movement. The resulting integrated COM (iCOM) STEM technique yields a scalar image that is linear in the phase shift caused by the sample and therefore also in the local (projected) electrostatic potential field of a thin sample. We confirm that the differential phase contrast (DPC) STEM technique using a segmented detector with 4 quadrants (4Q) yields a good approximation for the COM movement. Performing a two-dimensional integration, just as for the COM, we obtain an integrated DPC (iDPC) image which is approximately linear in the phase of the sample. Beside deriving the CTFs of iCOM and iDPC, we clearly point out the objects of the two corresponding imaging techniques, and highlight the differences to objects corresponding to COM-, DPC-, and (HA) ADF-STEM. The theory is validated with simulations and we present first experimental results of the iDPC-STEM technique showing its capability for imaging both light and heavy elements with atomic resolution and a good signal to noise ratio (SNR). Copyright © 2015 Elsevier B.V. All rights reserved.

Left ventricular volume measurements with free breathing respiratory self-gated 3-dimensional golden angle radial whole-heart cine imaging - Feasibility and reproducibility.

Science.gov (United States)

Holst, Karen; Ugander, Martin; Sigfridsson, Andreas

2017-11-01

To develop and evaluate a free breathing respiratory self-gated isotropic resolution technique for left ventricular (LV) volume measurements. A 3D radial trajectory with double golden-angle ordering was used for free-running data acquisition during free breathing in 9 healthy volunteers. A respiratory self-gating signal was extracted from the center of k-space and used with the electrocardiogram to bin all data into 3 respiratory and 25 cardiac phases. 3D image volumes were reconstructed and the LV endocardial border was segmented. LV volume measurements and reproducibility from 3D free breathing cine were compared to conventional 2D breath-held cine. No difference was found between 3D free breathing cine and 2D breath-held cine with regards to LV ejection fraction, stroke volume, end-systolic volume and end-diastolic volume (Pcine and 2D breath-held cine (Pcine and conventional 2D breath-held cine showed similar values and test-retest repeatability for LV volumes in healthy volunteers. 3D free breathing cine enabled retrospective sorting and arbitrary angulation of isotropic data, and could correctly measure LV volumes during free breathing acquisition. Copyright © 2017 Elsevier Inc. All rights reserved.

Cine MR CSF flow study in hydrocephalus: What are the valuable parmeters?

International Nuclear Information System (INIS)

Choi, Hye Young; Kim, Myung Hyun

1997-01-01

To evaluate the changes in diagnosis of intracranial cerebrospinal fluid (CSF) dynamics in the hydrocephalus, we studied the various parameters of cine phase contrast (PC) magnetic resonance (MR) CSF flow images in cases of acutely progressive hydrocephalus, comparing them with those in normal CSF circulation. The MR images were obtained with a 1.5T (GE Signa, GE Medical Systems, Milwaukee, USA) unit using the 2 dimensional cine PC sequence with peripheral gating and gradient recalled echo imaging in ten cases of non-obstructive hydrocephalus(NOH), three of obstructive hydrocephalus(OH), and ten controls. The time-echo time-flip angle employed were 50 to 80 msec-11 to 15 msec-12 to 15 degrees. Temporal velocity information relating to cervical pericord CSF spaces, third and fourth ventricles, and the aqueduct were plotted as wave forms which were then analyzed for configuration, amplitude parameters(Vmax, Vmin, Vdif), and temporal parameters(R-S, R-SMV, R-D, R-DMV). The statistical significance of each parameter was examined using the paired t-test. All patients with OH underwent endoscopic third ventriculostomy, whereas all with NOH underwent shunting procedures. In five ROIs, distinct reproducible configuration features were obtained at aqueduct and cervical pericord spaces, but not at ventricular levels. We determined the statistically significant differences between controls and hydrocephalus patients using temporal, rather than amplitude parameters. In NOH, the graph showed R-DMV shortening (p<0.01) at the anterior cervical pericord space. In OH, there were R-DMV shortening (p<0.05) was seen at the anterior cervical pericord space, and R-DMV shortening (p<0.02) at the posterior cervical pericord space. In one case of OH, a typical change of configuration, mirror image, was obtained at aqueduct level, and in all OH cases, the level of obstruction could be determined. The results of cine PC MR CSF flow study may be valuable for points for determining the level

Cine y literatura: Narrativa de la identidad

OpenAIRE

Laverde Román, Alejandra; Parra, Martha Ligia; Montoya Giraldo, Alejandra; Uribe Alzate, Yennifer; Tobar Álvarez, Margarita

2010-01-01

Este artículo es resultado de la investigación La narrativa literaria y audiovisual en la construcción de la identidad cultural colombiana. Una mirada desde el cine y la literatura: adaptaciones de obras literarias llevadas al cine entre 1920 y 2008-1. En el presente texto se desarrolla un análisis de la relación de cine y literatura en la construcción de la identidad colombiana, a partir del rastreo bibliográfico de la crítica y las historias literarias y cinematográficas a un corpus selecci...

CineGlob

CERN Multimedia

CineGlob

2014-01-01

CERN will be hosting the next CineGlobe International Film Festival from March 18 to 23 at the Globe of Science and Innovation with the theme “Beyond the Frontier”, This 4th edition will see 66 short films “inspired by science” in competition, including fiction films as well as documentaries. From Tuesday the 18th to Friday the 21st, special lunch sessions are organized from 12:30 to 13:30. Food will be available for purchase at the tent “Café Cinéma” next to the Globe. Special evenings While the short film screenings are the heart of the festival, every year CineGlobe also organizes compelling special events every night, from feature films to special musical performances: Tuesday 18th: The Swiss premiere of the acclaimed documentary film Particle Fever. Presented by BBC Storyville with Fabiola Gianotti and director Mark Levinson in attendance; Wednesday 19th: The result of the “Story Matter” Hacka...

Cine-MR imaging of valvular heart disease

International Nuclear Information System (INIS)

Park, Jae Hyung; Han, Man Chung; Kim, Chu Wan; Kim, Dae Jin; Kim, Woo Sung; Park, Hyun Wuk; Cho, Zang Hee

1989-01-01

Cine-MR imaging was done in 2 normal persons and 9 patients of valvular heart disease with 2.0 T superconducting MR system (Spectro-2000; GoldStar, Korea). The MRI was undertaken using gradient echo technique with small flip angle. Repetition time (TR) was 34 msec, and echo time (TE), 18 msec. In most cases, 20 to 30 frames could be obtained during one cardiac cycle. With normal heart, high signal intensity was identified in the blood filled cardiac chambers. Transient signal void was observed near tricuspid, mitral and aortic valves due to the turbulences induced by valve opening or closure. In 6 cases of mitral valvular disease, mitral valve was identified in all cases. The valvular motion was limited revealing doming toward cardiac apex during diastole. Signal void was evident in pansystolic phase of left ventricle in all cases. Evidence of combined aortic or tricuspid valve disease were also demonstrated, revealing signal void in the corresponding cardiac chambers. Cine-MRI seemed to be not only a good non-invasive diagnostic modality for the valvular heart disease, but also an accurate modality for cardiac functional evaluation

Cine-MR imaging of valvular heart disease

Energy Technology Data Exchange (ETDEWEB)

Park, Jae Hyung; Han, Man Chung; Kim, Chu Wan [Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Dae Jin; Kim, Woo Sung; Park, Hyun Wuk; Cho, Zang Hee [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

1989-04-15

Cine-MR imaging was done in 2 normal persons and 9 patients of valvular heart disease with 2.0 T superconducting MR system (Spectro-2000; GoldStar, Korea). The MRI was undertaken using gradient echo technique with small flip angle. Repetition time (TR) was 34 msec, and echo time (TE), 18 msec. In most cases, 20 to 30 frames could be obtained during one cardiac cycle. With normal heart, high signal intensity was identified in the blood filled cardiac chambers. Transient signal void was observed near tricuspid, mitral and aortic valves due to the turbulences induced by valve opening or closure. In 6 cases of mitral valvular disease, mitral valve was identified in all cases. The valvular motion was limited revealing doming toward cardiac apex during diastole. Signal void was evident in pansystolic phase of left ventricle in all cases. Evidence of combined aortic or tricuspid valve disease were also demonstrated, revealing signal void in the corresponding cardiac chambers. Cine-MRI seemed to be not only a good non-invasive diagnostic modality for the valvular heart disease, but also an accurate modality for cardiac functional evaluation.

Cine y publicidad. Análisis de seis anuncios publicitarios realizados por directores de cine

OpenAIRE

Caballero Álvarez, Fernando

2015-01-01

Esta investigación tiene como objetivo de estudio analizar los trabajos llevados a cabo por diversos directores de cine de este país a marcas en un periodo de crisis en el que apuestan por trabajos de mayor calidad. Buscaremos aquellos elementos que diferencian a estos anuncios de cualquier otro no firmado por un director de cine y cuál podría ser el objetivo que buscan las marcas al apostar por ellos. Grado en Publicidad y Relaciones Públicas

Cine y literatura

Directory of Open Access Journals (Sweden)

Jorge Enrique Adoum

2015-01-01

Full Text Available El lanzamiento de la undécima edición de la novela de Jorge Enrique Adoum "Entre Marx y una mujer desnuda" y el comienzo simultáneo de la filmación de la película basada en esa obra, ha puesto nuevamente de relieve, el recurrente tema de la literatura llevada al cine. En ese sentido, en agosto, se llevó a cabo una mesa redonda en la que participaron como exponentes Camilo Luzuriaga (director del filme, Omar Ospina (crítico cinematográfico y jorge Enrique Adoum. En el siguiente artículo -basado en su exposición en la mesa redonda-, el reconocido escritor analiza cómo debe ser para él la vinculación entre literatura y cine.

X-ray Phase Contrast analysis - Digital wavefront development

International Nuclear Information System (INIS)

Idir, Mourad; Potier, Jonathan; Fricker, Sebastien; Snigirev, Anatoly; Snigireva, Irina; Modi, M. H.

2010-01-01

Optical schemes that enable imaging of the phase shift produced by an object have become popular in the x-ray region, where phase can be the dominant contrast mechanism. The propagation-based technique consists of recording the interference pattern produced by choosing one or several sample-to-detector distances. Pioneering studies, carried out making use of synchrotron radiation, demonstrated that this technique results in a dramatic increase of image contrast and detail visibility, allowing the detection of structures invisible with conventional techniques. An experimental and theoretical study of in-line hard x-ray phase-contrast imaging had been performed. The theoretical description of the technique is based on Fresnel diffraction. As an illustration of the potential of this quantitative imaging technique, high-resolution x-ray phase contrast images of simple objects will be presented.

Isotropic differential phase contrast microscopy for quantitative phase bio-imaging.

Science.gov (United States)

Chen, Hsi-Hsun; Lin, Yu-Zi; Luo, Yuan

2018-05-16

Quantitative phase imaging (QPI) has been investigated to retrieve optical phase information of an object and applied to biological microscopy and related medical studies. In recent examples, differential phase contrast (DPC) microscopy can recover phase image of thin sample under multi-axis intensity measurements in wide-field scheme. Unlike conventional DPC, based on theoretical approach under partially coherent condition, we propose a new method to achieve isotropic differential phase contrast (iDPC) with high accuracy and stability for phase recovery in simple and high-speed fashion. The iDPC is simply implemented with a partially coherent microscopy and a programmable thin-film transistor (TFT) shield to digitally modulate structured illumination patterns for QPI. In this article, simulation results show consistency of our theoretical approach for iDPC under partial coherence. In addition, we further demonstrate experiments of quantitative phase images of a standard micro-lens array, as well as label-free live human cell samples. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Usefulness of Dynamic Cine-Arthrography for Wrist Instability as Correlated with Arthroscopic Palmer Classification

Energy Technology Data Exchange (ETDEWEB)

Kim TaeYeon; Lee, Guen Young; Kim, Baek Hyun; Park, Jong Woong; Seo, Bo Kyoung; Cha, Sang Hoon [Korea University Ansan Hospital, Korea University College of Medicine, Ansan (Korea, Republic of)

2011-05-15

To introduce dynamic cine-arthrography and compare it with MR arthrography in the diagnosis of intrinsic ligament and triangular fibrocartilage complex tears, based on arthroscopic findings. A total of thirty-eight wrists of 38 patients who had undergone both dynamic cine-arthrography and MR arthrography were enrolled. Dynamic cinearthrography was performed after puncture of the radiocarpal joint by slow injection of contrast under continuous fluoroscopic guidance during passive wrist exercise. We obtained 1.5- or 3-T MR arthrography with fat-suppressed T1-weighted coronal and axial images. We evaluated scapholunate and lunotriquetral ligaments and triangular fibrocartilage complex tears according to the Palmer classification system. Based on the arthroscopic findings, we compared the diagnostic values between the two examinations using Kappa values. The overall sensitivity and specificity of diagnosis of intrinsic ligament tears was similar between dynamic cine-arthrography and MR arthrography (scapholunate ligament: sensitivity 66.7% vs. 80%, specificity 100% vs. 95.7%, lunotriquetral ligament: sensitivity 75.0% vs. 75.0%, specificity 94.1% vs. 91.2%). For triangular fibrocartilage complex tears, all diagnostic values were the same (sensitivity 96.4%, specificity 100%). The inter-examination agreement was substantial to perfect (kappa value 1.000). Dynamic cine-arthrography is valuable in the diagnosis of intrinsic ligament and triangular fibrocartilage complex tears compared to MR arthrography.

El cine de terror español

OpenAIRE

Gómez Llorente, Tatiana

2015-01-01

La autora comienza haciendo un estudio del cine de terror desde sus inicios, sus subgéneros, mecanimos utilizados para provocar el miedo en el espectador para finalmente centrarse en el cine de terror español a través de cinco películas representativas del género.

Highly-Accelerated Real-Time Cardiac Cine MRI Using k-t SPARSE-SENSE

Science.gov (United States)

Feng, Li; Srichai, Monvadi B.; Lim, Ruth P.; Harrison, Alexis; King, Wilson; Adluru, Ganesh; Dibella, Edward VR.; Sodickson, Daniel K.; Otazo, Ricardo; Kim, Daniel

2012-01-01

For patients with impaired breath-hold capacity and/or arrhythmias, real-time cine MRI may be more clinically useful than breath-hold cine MRI. However, commercially available real-time cine MRI methods using parallel imaging typically yield relatively poor spatio-temporal resolution due to their low image acquisition speed. We sought to achieve relatively high spatial resolution (~2.5mm × 2.5mm) and temporal resolution (~40ms), to produce high-quality real-time cine MR images that could be applied clinically for wall motion assessment and measurement of left ventricular (LV) function. In this work, we present an 8-fold accelerated real-time cardiac cine MRI pulse sequence using a combination of compressed sensing and parallel imaging (k-t SPARSE-SENSE). Compared with reference, breath-hold cine MRI, our 8-fold accelerated real-time cine MRI produced significantly worse qualitative grades (1–5 scale), but its image quality and temporal fidelity scores were above 3.0 (adequate) and artifacts and noise scores were below 3.0 (moderate), suggesting that acceptable diagnostic image quality can be achieved. Additionally, both 8-fold accelerated real-time cine and breath-hold cine MRI yielded comparable LV function measurements, with coefficient of variation cine MRI with k-t SPARSE-SENSE is a promising modality for rapid imaging of myocardial function. PMID:22887290

Highly accelerated real-time cardiac cine MRI using k-t SPARSE-SENSE.

Science.gov (United States)

Feng, Li; Srichai, Monvadi B; Lim, Ruth P; Harrison, Alexis; King, Wilson; Adluru, Ganesh; Dibella, Edward V R; Sodickson, Daniel K; Otazo, Ricardo; Kim, Daniel

2013-07-01

For patients with impaired breath-hold capacity and/or arrhythmias, real-time cine MRI may be more clinically useful than breath-hold cine MRI. However, commercially available real-time cine MRI methods using parallel imaging typically yield relatively poor spatio-temporal resolution due to their low image acquisition speed. We sought to achieve relatively high spatial resolution (∼2.5 × 2.5 mm(2)) and temporal resolution (∼40 ms), to produce high-quality real-time cine MR images that could be applied clinically for wall motion assessment and measurement of left ventricular function. In this work, we present an eightfold accelerated real-time cardiac cine MRI pulse sequence using a combination of compressed sensing and parallel imaging (k-t SPARSE-SENSE). Compared with reference, breath-hold cine MRI, our eightfold accelerated real-time cine MRI produced significantly worse qualitative grades (1-5 scale), but its image quality and temporal fidelity scores were above 3.0 (adequate) and artifacts and noise scores were below 3.0 (moderate), suggesting that acceptable diagnostic image quality can be achieved. Additionally, both eightfold accelerated real-time cine and breath-hold cine MRI yielded comparable left ventricular function measurements, with coefficient of variation cine MRI with k-t SPARSE-SENSE is a promising modality for rapid imaging of myocardial function. Copyright © 2012 Wiley Periodicals, Inc.

Validation of in vivo 2D displacements from spiral cine DENSE at 3T.

Science.gov (United States)

Wehner, Gregory J; Suever, Jonathan D; Haggerty, Christopher M; Jing, Linyuan; Powell, David K; Hamlet, Sean M; Grabau, Jonathan D; Mojsejenko, Walter Dimitri; Zhong, Xiaodong; Epstein, Frederick H; Fornwalt, Brandon K

2015-01-30

Displacement Encoding with Stimulated Echoes (DENSE) encodes displacement into the phase of the magnetic resonance signal. Due to the stimulated echo, the signal is inherently low and fades through the cardiac cycle. To compensate, a spiral acquisition has been used at 1.5T. This spiral sequence has not been validated at 3T, where the increased signal would be valuable, but field inhomogeneities may result in measurement errors. We hypothesized that spiral cine DENSE is valid at 3T and tested this hypothesis by measuring displacement errors at both 1.5T and 3T in vivo. Two-dimensional spiral cine DENSE and tagged imaging of the left ventricle were performed on ten healthy subjects at 3T and six healthy subjects at 1.5T. Intersection points were identified on tagged images near end-systole. Displacements from the DENSE images were used to project those points back to their origins. The deviation from a perfect grid was used as a measure of accuracy and quantified as root-mean-squared error. This measure was compared between 3T and 1.5T with the Wilcoxon rank sum test. Inter-observer variability of strains and torsion quantified by DENSE and agreement between DENSE and harmonic phase (HARP) were assessed by Bland-Altman analyses. The signal to noise ratio (SNR) at each cardiac phase was compared between 3T and 1.5T with the Wilcoxon rank sum test. The displacement accuracy of spiral cine DENSE was not different between 3T and 1.5T (1.2 ± 0.3 mm and 1.2 ± 0.4 mm, respectively). Both values were lower than the DENSE pixel spacing of 2.8 mm. There were no substantial differences in inter-observer variability of DENSE or agreement of DENSE and HARP between 3T and 1.5T. Relative to 1.5T, the SNR at 3T was greater by a factor of 1.4 ± 0.3. The spiral cine DENSE acquisition that has been used at 1.5T to measure cardiac displacements can be applied at 3T with equivalent accuracy. The inter-observer variability and agreement of DENSE-derived peak strains and

Dobutamine cine magnetic resonance imaging after myocardial infarction

International Nuclear Information System (INIS)

Giovagnoni, A.; Ligabue, G.; Romagnoli, R.; Reggio Emilia Univ., Reggio Emilia; Rossi, R.; Muia, N.; Modena, M.G.; Reggio Emilia Univ.

1999-01-01

Dobutamine Cine MRI is a new diagnostic imaging technique in the pretreatment (revascularization) assessment of myocardial infarction patients. In this issue are reported the result of a comparative study of the diagnostic yield of dobutamine Cine MRI with that of stress echocardiography in the assessment of viable myocardium. A new method for analysis of Cine MR images, employing digital subtraction, aimed at decreasing subjectivity in the quantitative assessment of myocardial wall thickening. Twenty-six patients (21 men and 5 women) with a history of myocardial infarction who were scheduled for revascularization were submitted to stress echocardiography and dobutamine Cine MRI to evaluate contractile recovery of the segments considered akinetic or hypo kinetic at baseline echocardiography. Dobutamine was administered in growing doses (5, 10, 15γ/kg/min). 16 segments of the left ventricle in each patient were considered. In the 416 segments studied, it was found that 307 normo kinetic, 64 scarred and 45 viable segments with stress echocardiography, versus 302 normo kinetic, 83 scarred and 31 viable segments with dobutamine MRI. Three months after revascularization 15 patients were examined to check contractile recovery of the segments considered as viable. Echocardiography had 79% sensitivity and 97% specificity, while Cine MRI had 96% and 86%, respectively. In patients with anteroseptal wall myocardial infarction stress echocardiography had 75% sensitivity and 97% specificity. Echocardiography permits to distinguish viable myocardium and scarred myocardial tissue with good sensitivity and specificity, but Cine MRI performs better. Cine MRI has much higher sensitivity than stress echocardiography and thus makes the technique of choice to evaluate viable myocardium in these sites. The digital subtraction technique is as accurate as manual measurements, but reduces the error rate and permits quicker evaluation, particularly in subendocardial thickening [it

Cine magnetic resonance imaging in congenital heart disease

International Nuclear Information System (INIS)

Akagi, Teiji; Kiyomatsu, Yumi; Kato, Hirohisa; Abe, Toushi; Nishimura, Hiroshi; Ohtake, Hisashi; Eto, Takaharu.

1989-01-01

Cine magnetic resonance imaging (MRI) was performed in 33 patients aged 19 days to 18 years (mean 5.1 years), who had congenital heart disease comfirmed at echocardiography or angiography. Prior to cine MRI, gated MRI with spin echo (SE) sequence was perfomed to evaluate cardiac structure. Cine MRI was demonstrated by fast low fip angle shot imaging technique with a 30 deg flip angle, 15 msec echo time, 30∼40 msec pulse repetition time, and 128X128 acquisition matrix. Abnormalities of cardiac structure were extremely well defined in all patients. Intracardiac and intravasucular blood flow were visualized with high signal intensity area, whereas ventricular filling flow and left to right shunt flow through ventricular septal defect and atrial septal defect were visualized with low signal intensity area. However, in the patients who had severe congestive heart failure or respiratory arrhythmia, the good recording of cine MRI was not obtained because of artifacts. Gated MRI with SE sequence provides excellent visualization of fine structures, and cine MRI can provide high spatial resolution imaging of flow dynamic in a variety of congenital heart disease, noninvasively. (author)

Compressed sensing real-time cine cardiovascular magnetic resonance: accurate assessment of left ventricular function in a single-breath-hold.

Science.gov (United States)

Kido, Tomoyuki; Kido, Teruhito; Nakamura, Masashi; Watanabe, Kouki; Schmidt, Michaela; Forman, Christoph; Mochizuki, Teruhito

2016-08-24

Cardiovascular cine magnetic resonance (CMR) accelerated by compressed sensing (CS) is used to assess left ventricular (LV) function. However, it is difficult for prospective CS cine CMR to capture the complete end-diastolic phase, which can lead to underestimation of the end-diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF), compared to retrospective standard cine CMR. This prospective study aimed to evaluate the diagnostic quality and accuracy of single-breath-hold full cardiac cycle CS cine CMR, acquired over two heart beats, to quantify LV volume in comparison to multi-breath-hold standard cine CMR. Eighty-one participants underwent standard segmented breath-hold cine and CS real-time cine CMR examinations to obtain a stack of eight contiguous short-axis images with same high spatial (1.7 × 1.7 mm(2)) and temporal resolution (41 ms). Two radiologists independently performed qualitative analysis of image quality (score, 1 [i.e., "nondiagnostic"] to 5 [i.e., "excellent"]) and quantitative analysis of the LV volume measurements. The total examination time was 113 ± 7 s for standard cine CMR and 24 ± 4 s for CS cine CMR (p cine image quality was slightly lower than standard cine (4.8 ± 0.5 for standard vs. 4.4 ± 0.5 for CS; p cine were above 4 (i.e., good). No significant differences existed between standard and CS cine MR for all quantitative LV measurements. The mean differences with 95 % confidence interval (CI), based on Bland-Altman analysis, were 1.3 mL (95 % CI, -14.6 - 17.2) for LV end-diastolic volume, 0.2 mL (95 % CI, -9.8 to10.3) for LV end-systolic volume, 1.1 mL (95 % CI, -10.5 to 12.7) for LV stroke volume, 1.0 g (95 % CI, -11.2 to 13.3) for LV mass, and 0.4 % (95 % CI, -4.8 - 5.6) for LV ejection fraction. The interobserver and intraobserver variability for CS cine MR ranged from -4.8 - 1.6 % and from -7.3 - 9.3 %, respectively, with slopes of the regressions ranging 0.88-1.0 and 0

Impact of low signal intensity assessed by cine magnetic resonance imaging on detection of poorly viable myocardium in patients with prior myocardial infarction.

Science.gov (United States)

Ota, Shingo; Tanimoto, Takashi; Orii, Makoto; Hirata, Kumiko; Shiono, Yasutsugu; Shimamura, Kunihiro; Matsuo, Yoshiki; Yamano, Takashi; Ino, Yasushi; Kitabata, Hironori; Yamaguchi, Tomoyuki; Kubo, Takashi; Tanaka, Atsushi; Imanishi, Toshio; Akasaka, Takashi

2015-05-13

Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) has been established as a modality to detect myocardial infarction (MI). However, the use of gadolinium contrast is limited in patients with advanced renal dysfunction. Although the signal intensity (SI) of infarct area assessed by cine MRI is low in some patients with prior MI, the prevalence and clinical significance of low SI has not been evaluated. The aim of this study was to evaluate how low SI assessed by cine MRI may relate to the myocardial viability in patients with prior MI. Fifty patients with prior MI underwent both cine MRI and LGE-MRI. The left ventricle was divided into 17 segments. The presence of low SI and the wall motion score (WMS) of each segment were assessed by cine MRI. The transmural extent of infarction was evaluated by LGE-MRI. LGE was detected in 329 of all 850 segments (39%). The low SI assessed by cine MRI was detected in 105 of 329 segments with LGE (32%). All segments with low SI had LGE. Of all 329 segments with LGE, the segments with low SI showed greater transmural extent of infarction (78 [72 - 84] % versus 53 [38 - 72] %, P cine MRI may be effective for detecting poorly viable myocardium in patients with prior MI.

Phase retrieval for X-ray in-line phase contrast imaging

International Nuclear Information System (INIS)

Scattarella, F.; Bellotti, R.; Tangaro, S.; Gargano, G.; Giannini, C.

2011-01-01

A review article about phase retrieval problem in X-ray phase contrast imaging is presented. A simple theoretical framework of Fresnel diffraction imaging by X-rays is introduced. A review of the most important methods for phase retrieval in free-propagation-based X-ray imaging and a new method developed by our collaboration are shown. The proposed algorithm, Combined Mixed Approach (CMA) is based on a mixed transfer function and transport of intensity approach, and it requires at most an initial approximate estimate of the average phase shift introduced by the object as prior knowledge. The accuracy with which this initial estimate is known determines the convenience speed of algorithm. The new proposed algorithm is based on the retrieval of both the object phase and its complex conjugate. The results obtained by the algorithm on simulated data have shown that the obtained reconstructed phase maps are characterized by particularly low normalized mean square errors. The algorithm was also tested on noisy experimental phase contrast data, showing a good efficiency in recovering phase information and enhancing the visibility of details inside soft tissues.

Bi-directional x-ray phase-contrast mammography.

Directory of Open Access Journals (Sweden)

Kai Scherer

Full Text Available Phase-contrast x-ray imaging is a promising improvement of conventional absorption-based mammography for early tumor detection. This potential has been demonstrated recently, utilizing structured gratings to obtain differential phase and dark-field scattering images. However, the inherently anisotropic imaging sensitivity of the proposed mono-directional approach yields only insufficient diagnostic information, and has low diagnostic sensitivity to highly oriented structures. To overcome these limitations, we present a two-directional x-ray phase-contrast mammography approach and demonstrate its advantages by applying it to a freshly dissected, cancerous mastectomy breast specimen. We illustrate that the two-directional scanning procedure overcomes the insufficient diagnostic value of a single scan, and reliably detects tumor structures, independently from their orientation within the breast. Our results indicate the indispensable diagnostic necessity and benefit of a multi-directional approach for x-ray phase-contrast mammography.

Real-time SPARSE-SENSE cardiac cine MR imaging: optimization of image reconstruction and sequence validation.

Science.gov (United States)

Goebel, Juliane; Nensa, Felix; Bomas, Bettina; Schemuth, Haemi P; Maderwald, Stefan; Gratz, Marcel; Quick, Harald H; Schlosser, Thomas; Nassenstein, Kai

2016-12-01

Improved real-time cardiac magnetic resonance (CMR) sequences have currently been introduced, but so far only limited practical experience exists. This study aimed at image reconstruction optimization and clinical validation of a new highly accelerated real-time cine SPARSE-SENSE sequence. Left ventricular (LV) short-axis stacks of a real-time free-breathing SPARSE-SENSE sequence with high spatiotemporal resolution and of a standard segmented cine SSFP sequence were acquired at 1.5 T in 11 volunteers and 15 patients. To determine the optimal iterations, all volunteers' SPARSE-SENSE images were reconstructed using 10-200 iterations, and contrast ratios, image entropies, and reconstruction times were assessed. Subsequently, the patients' SPARSE-SENSE images were reconstructed with the clinically optimal iterations. LV volumetric values were evaluated and compared between both sequences. Sufficient image quality and acceptable reconstruction times were achieved when using 80 iterations. Bland-Altman plots and Passing-Bablok regression showed good agreement for all volumetric parameters. 80 iterations are recommended for iterative SPARSE-SENSE image reconstruction in clinical routine. Real-time cine SPARSE-SENSE yielded comparable volumetric results as the current standard SSFP sequence. Due to its intrinsic low image acquisition times, real-time cine SPARSE-SENSE imaging with iterative image reconstruction seems to be an attractive alternative for LV function analysis. • A highly accelerated real-time CMR sequence using SPARSE-SENSE was evaluated. • SPARSE-SENSE allows free breathing in real-time cardiac cine imaging. • For clinically optimal SPARSE-SENSE image reconstruction, 80 iterations are recommended. • Real-time SPARSE-SENSE imaging yielded comparable volumetric results as the reference SSFP sequence. • The fast SPARSE-SENSE sequence is an attractive alternative to standard SSFP sequences.

Single-shot quantitative phase microscopy with color-multiplexed differential phase contrast (cDPC.

Directory of Open Access Journals (Sweden)

Zachary F Phillips

Full Text Available We present a new technique for quantitative phase and amplitude microscopy from a single color image with coded illumination. Our system consists of a commercial brightfield microscope with one hardware modification-an inexpensive 3D printed condenser insert. The method, color-multiplexed Differential Phase Contrast (cDPC, is a single-shot variant of Differential Phase Contrast (DPC, which recovers the phase of a sample from images with asymmetric illumination. We employ partially coherent illumination to achieve resolution corresponding to 2× the objective NA. Quantitative phase can then be used to synthesize DIC and phase contrast images or extract shape and density. We demonstrate amplitude and phase recovery at camera-limited frame rates (50 fps for various in vitro cell samples and c. elegans in a micro-fluidic channel.

Dual breath-hold magnetic resonance cine evaluation of global and regional cardiac function

International Nuclear Information System (INIS)

Wintersperger, Bernd J.; Dietrich, Olaf; Huber, Armin; Reiser, Maximilian F.; Schoenberg, Stefan O.; Sincleair, Spencer; Runge, Val M.

2007-01-01

The purpose of our study was to evaluate the accuracy of a multislice cine magnetic resonance imaging (MRI) technique with parallel imaging in regard to global and regional left ventricular function. Forty-two individuals underwent cine MRI on a 1.5-tesla scanner. Cine MRI used a steady-state free precession technique and was performed as a single-slice technique (nonTSENSE cine) and an accelerated multislice technique (TSENSE cine) with five slices per breath-hold. End diastolic volume (EDV), end systolic volume (ESV), and ejection fraction (EF) were evaluated for all data sets and in regard to regional wall motion and regional wall motion analysis, and quantitative regional wall thickness and systolic thickening were also assessed. EDV, ESV, and EF based on TSENSE cine showed excellent correlation to the nonTSENSE cine approach (all r 2 =0.99, P<0.001). While EDV evaluations showed a small underestimation for TSENSE cine, ESV and EF showed accurate results compared with nonTSENSE cine. Both readers showed good agreement (κ=0.72) in regional wall motion assessment comparing both techniques. Data acquisition for the multislice approach was significantly shorter (∝75%) that in single-slice cine. We conclude that accurate evaluation of regional wall motion and left ventricular EF is possible using accelerated multislice cine MR with high spatial and temporal resolution. (orig.)

Cine-Club

CERN Multimedia

Cine-Club

2013-01-01

The CERN CineClub is a meeting point every Thursday for anyone who wants to discover, discuss, and appreciate cinema with people who are truly interested in the art of the moving image. In the actual context where downloading became easier than cooking an egg, one might wonder why bother when it can be watched on any computer. Well, cinema is not an individual activity. What the CineClub offers is a big screen with good quality image and sound. It also offers a careful selection, for allowing people to (re-)discover new and forgotten authors. Finally, it offers the opportunity for meeting people sharing a common interest. So come every Thursday, and see by yourself that watching films can actually be a real party! Every Thursday at 20 h 00 Council Chamber, 503/1-001 Programme June 2013 Science Fiction Cycle “Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution.” 6th June 2...

SU-C-202-07: Protocol and Hardware for Improved Flood Field Calibration of TrueBeam FFF Cine Imaging

Energy Technology Data Exchange (ETDEWEB)

Adamson, J; Faught, A; Yin, F [Duke University Medical Center, Durham, NC (United States)

2016-06-15

Purpose: Flattening filter free photon energies are commonly used for high dose treatments such as SBRT, where localization accuracy is essential. Often, MV cine imaging may be employed to verify correct localization. TrueBeam Electronic Portal Imaging Devices (EPIDs) equipped with the 40×30cm{sup 2} Image Detection Unit (IDU) are prone to image saturation at the image center especially for higher dose rates. While saturation often does not occur for cine imaging during treatment because the beam is attenuated by the patient, the flood field calibration is affected when the standard calibration procedure is followed. Here we describe the hardware and protocol to achieve improved image quality for this model of TrueBeam EPID. Methods: A stainless steel filter of uniform thickness was designed to have sufficient attenuation to avoid panel saturation for both 6XFFF and 10XFFF at the maximum dose rates (1400 MU/min & 2400 MU/min, respectively). The cine imaging flood field calibration was then acquired with the filter in place for the FFF energies under the standard calibration geometry (SDD=150cm). Image quality during MV cine was assessed with & without the modified flood field calibration using a low contrast resolution phantom and an anthropomorphic phantom. Results: When the flood field is acquired using the standard procedure (no filter in place), a pixel gain artifact is clearly present in the image center (r=3cm for 10XFFF at 2400 MU/min) which appears similar to and may be mis-attributed to panel saturation in the subject image. The artifact obscured all low contrast inserts at the image center and was also visible on the anthropomorphic phantom. Using the filter for flood field calibration eliminated the artifact. Conclusion: Use of a modified flood field calibration procedure improves image quality for cine MV imaging with TrueBeams equipped with the 40×30cm{sup 2} IDU.

Cine-MRI swallowing evaluation after tongue reconstruction

Energy Technology Data Exchange (ETDEWEB)

Hartl, Dana M. [Department of Otolaryngology-Head and Neck Surgery, Institute Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex (France)], E-mail: dmhartl@aol.com; Kolb, Frederic; Bretagne, Evelyne [Department of Otolaryngology-Head and Neck Surgery, Institute Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex (France); Bidault, Francois; Sigal, Robert [Department of Radiology, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex (France)

2010-01-15

Objective: To determine the feasibility of cine-MRI for non-invasive swallowing evaluation after surgery for lingual carcinoma with reconstruction using microvascular free flaps. Methods: Ten patients with stage IV carcinoma of the mobile tongue and/or tongue base treated by surgical resection and reconstruction with a free flap were evaluated after an average of 4.3 years (range: 1.5-11 years), using cine-MRI in 'single-shot fast spin echo' (SSFSE) mode. Fiberoptic laryngoscopy of swallowing was performed before MRI to detect aspiration. The tolerance and ability to complete the exam were noted. The mobilities of the oral and pharyngeal structures visualized were evaluated as normal, reduced or increased. Results: Cine-MRI was well tolerated in all cases; 'dry' swallow was performed for the 2 patients with clinical aspiration. Tongue base-pharyngeal wall contact was observed in 5 cases. An increased anterior tongue recoil, increased mandibular recoil, increased posterior oropharyngeal wall advancement and an increased laryngeal elevation were observed in 4 cases. One case of a passive 'slide' mechanism was observed. Conclusions: Cine-MRI is a safe, non-invasive technique for the evaluation of the mobility of oral and oropharyngeal structures after free-flap reconstruction of the tongue. For selected cases, it may be complementary to clinical examination for evaluation of dysphagia after surgery and free-flap reconstruction. Further technical advances will be necessary before cine-MRI can replace videofluoroscopy, however.

Cine-MRI swallowing evaluation after tongue reconstruction

International Nuclear Information System (INIS)

Hartl, Dana M.; Kolb, Frederic; Bretagne, Evelyne; Bidault, Francois; Sigal, Robert

2010-01-01

Objective: To determine the feasibility of cine-MRI for non-invasive swallowing evaluation after surgery for lingual carcinoma with reconstruction using microvascular free flaps. Methods: Ten patients with stage IV carcinoma of the mobile tongue and/or tongue base treated by surgical resection and reconstruction with a free flap were evaluated after an average of 4.3 years (range: 1.5-11 years), using cine-MRI in 'single-shot fast spin echo' (SSFSE) mode. Fiberoptic laryngoscopy of swallowing was performed before MRI to detect aspiration. The tolerance and ability to complete the exam were noted. The mobilities of the oral and pharyngeal structures visualized were evaluated as normal, reduced or increased. Results: Cine-MRI was well tolerated in all cases; 'dry' swallow was performed for the 2 patients with clinical aspiration. Tongue base-pharyngeal wall contact was observed in 5 cases. An increased anterior tongue recoil, increased mandibular recoil, increased posterior oropharyngeal wall advancement and an increased laryngeal elevation were observed in 4 cases. One case of a passive 'slide' mechanism was observed. Conclusions: Cine-MRI is a safe, non-invasive technique for the evaluation of the mobility of oral and oropharyngeal structures after free-flap reconstruction of the tongue. For selected cases, it may be complementary to clinical examination for evaluation of dysphagia after surgery and free-flap reconstruction. Further technical advances will be necessary before cine-MRI can replace videofluoroscopy, however.

Technical Note: Measurement of common carotid artery lumen dynamics using black-blood MR cine imaging.

Science.gov (United States)

Dai, Erpeng; Dong, Li; Zhang, Zhe; Li, Lyu; Zhang, Hui; Zhao, Xihai; Wang, Jinnan; Yuan, Chun; Guo, Hua

2017-03-01

To demonstrate the feasibility of measuring the common carotid artery (CCA) lumen dynamics using a black-blood cine (BB-cine) imaging method. Motion-sensitized driven-equilibrium (MSDE) prepared spoiled gradient sequence was used for the BB-cine imaging. CCAs of eleven healthy volunteers were studied using this method. Lumen dynamics, including lumen area evolution waveforms and distension values, were measured and evaluated by comparing this method with bright-blood cine (BrB-cine) imaging. Compared with the BrB-cine images, flow artifacts were effectively suppressed in the BB-cine images. BrB-cine images generally show larger lumen areas than BB-cine images. The lumen area waveforms and distension measurements from BB-cine imaging showed smaller variances among different subjects than BrB-cine imaging. The proposed BB-cine imaging technique can suppress the flow artifacts effectively and reduce the partial volume effects from the vessel wall. This might allow more accurate lumen dynamics measurements than traditional BrB-cine imaging, which may further be valuable for investigating biomechanical and functional properties of the cardiovascular system. © 2017 American Association of Physicists in Medicine.

Cine chileno e industria… el desafío que falta

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Fernando Véliz M.

2006-01-01

Full Text Available El cine chileno es un campo discursivo de la industria audiovisual aún en proceso de crecimiento. Su historia está cargada de imprecisiones y múltiples inicios que muchas veces quedan truncos; es un cine que se ha comprometido con los problemas sociales, pero que también ha sabido de lejanías y silencios impuestos; es un cine artesanal que aspira a mirar como industrial; es un cine que narra desde el tercer mundo, muchas veces con un 98% de consumo (en sus momentos más fuertes de producción norteamericana; es decir, es un cine que se ha formado en la autogestión absoluta de su capital simbólico. Es un cine que, por medio de libros y películas de culto, está generando una nueva camada de directores, los cuales buscan comprender su rol en esta industria que hoy, ya con el pasar del tiempo, tiene audiencias cautivas. Es un cine que a ratos camina junto al Estado y, en otras ocasiones, es la soledad su compañera de ruta. Es un cine fundado en la creatividad, búsqueda y superación de su oficio, y que poco a poco, comprende que el valor agregado está en sus historias locales.

Manifold learning based ECG-free free-breathing cardiac CINE MRI.

Science.gov (United States)

Usman, Muhammad; Atkinson, David; Kolbitsch, Christoph; Schaeffter, Tobias; Prieto, Claudia

2015-06-01

To present and validate a manifold learning (ML)-based method that can estimate both cardiac and respiratory navigator signals from electrocardiogram (ECG)-free free-breathing cardiac magnetic resonance imaging (MRI) data to achieve self-gated retrospective CINE reconstruction. In this work the use of the ML method is demonstrated for 2D cardiac CINE to achieve both cardiac and respiratory self-gating without the need of an external navigator or ECG signal. This is achieved by sequentially applying ML to two sets of retrospectively reconstructed real-time images with differing temporal resolutions. A 1D cardiac signal is estimated by applying ML to high temporal resolution real-time images reconstructed from the acquired data. Using the estimated cardiac signal, a 1D respiratory signal was obtained by applying the ML method to low temporal resolution images reconstructed from the same acquired data for each cardiac cycle. Data were acquired in five volunteers with a 2D golden angle radial trajectory in a balanced steady-state free precession (b-SSFP) acquisition. The accuracy of the estimated cardiac signal was calculated as the standard deviation of the temporal difference between the estimated signal and the recorded ECG. The correlation between the estimated respiratory signal and standard pencil beam navigator signal was evaluated. Gated CINE reconstructions (20 cardiac phases per cycle, temporal resolution ∼30 msec) using the estimated cardiac and respiratory signals were qualitatively compared against conventional ECG-gated breath-hold CINE acquisitions. Accurate cardiac signals were estimated with the proposed method, with an error standard deviation in comparison to ECG lower than 20 msec. Respiratory signals estimated with the proposed method achieved a mean cross-correlation of 94% with respect to standard pencil beam navigator signals. Good quality visual scores of 2.80 ± 0.45 (scores from 0, bad, to 4, excellent quality) were observed for the

Evaluation of right ventricular regional wall motion in inferior myocardial infarction by cine MRI

International Nuclear Information System (INIS)

Nishino, Masami; Ohnishi, Shusaku; Hasegawa, Shinji

1991-01-01

The purpose of this study is to evaluate right ventricular regional wall motion in inferior myocardial infarction by cine MRI. Thirteen patients with inferior myocardial infarction were investigated by cine MRI and were divided into proximal group which consisted of seven patients: >90% stenosis in segment 1 or 2 of right coronary artery and distal group which consisted of six patients: >90% stenosis in segment 3 or 4 of right coronary artery. Cine MRI was performed by 1.5 tesla magnet system (Signa, GE). To depict the regional asynergy, right ventricular wall was divided into 6 segments as follows: Segments 1 and 2 were upper and lower segments in transverse planes, respectively. Segments 3 and 4 were free wall and diaphragmatic segments of outflow tract, and segments 5 and 6 were of inflow tract in sagittal planes. Our results were as follows: (1) In proximal group, right ventricular asynergy was detected in six patients but in distal group it was detected in only one patient; (2) Right ventricular asynergy was detected most frequently at diaphragmatic segments in sagittal planes; (3) All the patients who had shown the hemodynamic deterioration of right ventricle on acute phase of inferior myocardial infarction presented the broad asynergy in right ventricle; (4) Cine MRI is clinically useful in evaluating right ventricular regional wall movement and diagnosing right ventricular infarction. (author)

Application of cine cardiac MR imaging in normal subjects and patients with valvular, coronary artery, and aortic disease

International Nuclear Information System (INIS)

Maddahi, J.; Ostrzega, E.; Crues, J.; Honma, H.; Siegel, R.; Charuzi, Y.; Berman, D.

1987-01-01

Cine MR imaging was performed on 15 normal subjects and 27 patients with cardiac disease. In normal subjects, high signal intensity of flowing blood contrasted with that of the myocardium. In 16 patients with valvular regurgitation, signal void jet due to turbulence was visualized across the diseased valves. In three IHSS patients, thickened LV myocardium, mitral regurgitant jets, and systolic LV outflow jets were noted. Five patients with myocardial infarction (MI) showed thinning and/or hypokinesis of MI regions. In three patients with Marfan syndrome, aortic dilatation, insufficiency, and flap (one pt) were identified. Cine MR imaging is potentially useful for evaluation of a variety of cardiac diseases

Imaging Three-Dimensional Myocardial Mechanics Using Navigator-gated Volumetric Spiral Cine DENSE MRI

Science.gov (United States)

Zhong, Xiaodong; Spottiswoode, Bruce S.; Meyer, Craig H.; Kramer, Christopher M.; Epstein, Frederick H.

2010-01-01

A navigator-gated 3D spiral cine displacement encoding with stimulated echoes (DENSE) pulse sequence for imaging 3D myocardial mechanics was developed. In addition, previously-described 2D post-processing algorithms including phase unwrapping, tissue tracking, and strain tensor calculation for the left ventricle (LV) were extended to 3D. These 3D methods were evaluated in 5 healthy volunteers, using 2D cine DENSE and historical 3D myocardial tagging as reference standards. With an average scan time of 20.5 ± 5.7 minutes, 3D data sets with a matrix size of 128 × 128 × 22, voxel size of 2.8 × 2.8 × 5.0 mm3, and temporal resolution of 32 ms were obtained with displacement encoding in three orthogonal directions. Mean values for end-systolic mid-ventricular mid-wall radial, circumferential, and longitudinal strain were 0.33 ± 0.10, −0.17 ± 0.02, and −0.16 ± 0.02, respectively. Transmural strain gradients were detected in the radial and circumferential directions, reflecting high spatial resolution. Good agreement by linear correlation and Bland-Altman analysis was achieved when comparing normal strains measured by 2D and 3D cine DENSE. Also, the 3D strains, twist, and torsion results obtained by 3D cine DENSE were in good agreement with historical values measured by 3D myocardial tagging. PMID:20574967

De Dickson a Lucas: Descubriendo el cine digital

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Carlos Eduardo Cortés S.

2015-01-01

Full Text Available La irrupción de la televisión en la vida cotidiana de los ciudadanos urbanos (1940 obligó al cine a cambiar su proporción de pantalla a fin de atraer espectadores. En América Latina los cineastas se han introducido de lleno en los terrenos digitales. El cine digital crea un cambio profundo en la forma en que las películas se envían, distribuyen y exhiben. Se trata también de renacer el cine independiente con la posibilidad de crear sistemas de producción y distribución de costo bajo y abrir exhibiciones propias por fuera de los circuitos comerciales. Es un hecho la coexistencia de cine, vídeo e Internet como las tres bases de una emergente industria contemporánea basada en la televisión digital (DTV, el formato de alta definición (HDTV y el soporte de DVD (vídeo digital versátil

Phase-contrast tomographic imaging using an X-ray interferometer

Energy Technology Data Exchange (ETDEWEB)

Momose, A. [Hitachi Ltd, Advanced Research Lab., Saitama (Japan); Takeda, T.; Itai, Y. [Univ. of Tsukuba, Inst. of Clinical Medicine, Ibaraki (Japan); Yoneyama, A. [Hitachi Ltd, Central Resarch Lab., Tokyo (Japan); Hirano, K. [High Energy Accelerator Research Organization, Inst. of Materials Structure Science, Ibaraki (Japan)

1998-05-01

Apparatus for phase-contrast X-ray computed tomography using a monolithic X-ray interferometer is presented with some observational results for human breast tissues. Structures characteristic of the tissues were revealed in the phase-contrast tomograms. The procedure of image analysis consists of phase retrieval from X-ray interference patterns and tomographic image reconstruction from the retrieved phase shift. Next, feasibility of phase-contrast imaging using a two-crystal X-ray interferometer was studied aiming at in vivo observation in the future. In a preliminary study, the two-crystal X-ray interferometer was capable of generating fringes of 70% visibility using synchrotron X-rays. 35 refs.

Phase-contrast tomographic imaging using an X-ray interferometer

International Nuclear Information System (INIS)

Momose, A.; Takeda, T.; Itai, Y.; Yoneyama, A.; Hirano, K.

1998-01-01

Apparatus for phase-contrast X-ray computed tomography using a monolithic X-ray interferometer is presented with some observational results for human breast tissues. Structures characteristic of the tissues were revealed in the phase-contrast tomograms. The procedure of image analysis consists of phase retrieval from X-ray interference patterns and tomographic image reconstruction from the retrieved phase shift. Next, feasibility of phase-contrast imaging using a two-crystal X-ray interferometer was studied aiming at in vivo observation in the future. In a preliminary study, the two-crystal X-ray interferometer was capable of generating fringes of 70% visibility using synchrotron X-rays

Evaluation of esophageal peristalsis in patients with esophageal tumors. Initial experience with cine MR imaging

International Nuclear Information System (INIS)

Koyama, Takashi; Kobayashi, Ari; Hiraga, Akira; Umeoka, Shigeaki; Saga, Tsuneo; Watanabe, Go; Tamai, Ken; Shimada, Yutaka; Togashi, Kaori

2005-01-01

We evaluated esophageal peristalsis in patients with esophageal tumors by cine MR using steady-state free precession (SSFP) sequence and correlated the alteration of the esophageal peristalsis with clinical symptoms and tumor stages. Thirteen patients with pathologically proven esophageal tumors, including 12 esophageal cancers and one submucosal leiomyoma, underwent cine MRI using true fast imaging with steady precession (trueFISP) sequence, which is one SSFP sequence, after contrast-enhanced MR scanning for clinical purposes. A total of 120 serial images were obtained within 60 s through the plane along the long axis of the esophagus while patients chewed gum. The serial trueFISP images were evaluated for the presence, frequency, speed of progression, and passage of peristalsis through the tumor. The data from cine MRI were compared with clinical symptoms and tumor stages. Peristalsis was clearly identified in all patients. Seven patients with complete interruption of peristalsis had dysphagia; one with partially impaired peristalsis could intake solid foods with discomfort; and two with partially impaired peristalsis and three with preserved peristalsis remained asymptomatic. Patients with complete or partial interruption of peristalsis had Stage T3 or T4 esophageal cancer. In conclusion, trueFISP cine MR imaging enables direct visualization of esophageal peristalsis in relation to esophageal tumors. Complete interruption of peristalsis causes dysphagia, whereas partial interruption of and preserved peristalsis usually do not cause digestive problems. Interruption of peristalsis may indicate impaired muscle function caused by invasion of advanced esophageal cancers. (author)

Spline based iterative phase retrieval algorithm for X-ray differential phase contrast radiography.

Science.gov (United States)

Nilchian, Masih; Wang, Zhentian; Thuering, Thomas; Unser, Michael; Stampanoni, Marco

2015-04-20

Differential phase contrast imaging using grating interferometer is a promising alternative to conventional X-ray radiographic methods. It provides the absorption, differential phase and scattering information of the underlying sample simultaneously. Phase retrieval from the differential phase signal is an essential problem for quantitative analysis in medical imaging. In this paper, we formalize the phase retrieval as a regularized inverse problem, and propose a novel discretization scheme for the derivative operator based on B-spline calculus. The inverse problem is then solved by a constrained regularized weighted-norm algorithm (CRWN) which adopts the properties of B-spline and ensures a fast implementation. The method is evaluated with a tomographic dataset and differential phase contrast mammography data. We demonstrate that the proposed method is able to produce phase image with enhanced and higher soft tissue contrast compared to conventional absorption-based approach, which can potentially provide useful information to mammographic investigations.

Three-dimensional cardiac cine imaging using the kat ARC acceleration: Initial experience in clinical adult patients at 3T.

Science.gov (United States)

Okuda, Shigeo; Yamada, Yoshitake; Tanimoto, Akihiro; Fujita, Jun; Sano, Motoaki; Fukuda, Keiichi; Kuribayashi, Sachio; Jinzaki, Masahiro; Nozaki, Atsushi; Lai, Peng

2015-09-01

Three-dimensional cardiac cine imaging has demonstrated promising clinical 1.5-Tesla results; however, its application to 3T scanners has been limited because of the higher sensitivity to off-resonance artifacts. The aim of this study was to apply 3D cardiac cine imaging during a single breath hold in clinical patients on a 3T scanner using the kat ARC (k- and adaptive-t auto-calibrating reconstruction for Cartesian sampling) technique and to evaluate the interchangeability between 2D and 3D cine imaging for cardiac functional analysis and detection of abnormalities in regional wall motion. Following institutional review board approval, we obtained 2D cine images with an acceleration factor of two during multiple breath holds and 3D cine images with a net scan acceleration factor of 7.7 during a single breath hold in 20 patients using a 3T unit. Two readers independently evaluated the wall motion of the left ventricle (LV) using a 5-point scale, and the consistency in the detection of regional wall motion abnormality between 2D and 3D cine was analyzed by Cohen's kappa test. The LV volume was calculated at end-diastole and end-systole (LVEDV, LVESV); the ejection fraction (LVEF) and myocardial weight (LVmass) were also calculated. The relationship between functional parameters calculated for 2D and 3D cine images was analyzed using Pearson's correlation analysis. The bias and 95% limit of agreement (LA) were calculated using Bland-Altman plots. In addition, a qualitative evaluation of image quality was performed with regard to the myocardium-blood contrast, noise level and boundary definition. Despite slight degradation in image quality for 3D cine, excellent agreement was obtained for the detection of wall motion abnormalities between 2D and 3D cine images (κ=0.84 and 0.94 for each reader). Excellent correlations between the two imaging methods were shown for the evaluation of functional parameters (r>0.97). Slight differences in LVEDV, LVESV, LVEF and LVmass

El cine posmoderno

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Edel Cadena Vargas

2015-05-01

Full Text Available En el presente trabajo se trata de dar respuesta a las siguientes preguntas: ¿cuál es el origen del cine posmoderno?, ¿cuáles son los factores que permiten su creación?, ¿a qué sentimiento responde?

Application of cine MRI-tagging method to aortic dessection

International Nuclear Information System (INIS)

Yoshioka, Kunihiro; Takahashi, Tsuneo; Kamata, Hiroyuki; Kikuchi, Kenichi; Yamaguchi, Kojiro.

1992-01-01

For the evaluation of aortic dissection, ECG-gated SE or cine MR imaging has been usually performed. However, detection of slow flow in the false lumen and differentiation between mural thrombus and slow flow are sometimes difficult. Because paradoxical enhancement due to slow blood flow simulates thrombus. We performed cine MR imaging with persaturation tagging, which clearly showed differentiation between thrombus and paradoxical enhancement. We concluded that cine MR imaging with tagging method was useful to evaluate the slow flow and thrombus in the false lumen. (author)

Cine MRI of Tracheal Dynamics in Healthy Volunteers and Patients With Tracheobronchomalacia.

Science.gov (United States)

Ciet, Pierluigi; Boiselle, Phillip M; Heidinger, Benedikt; Andrinopoulou, Eleni-Rosalina; O'Donnel, Carl; Alsop, David C; Litmanovich, Diana E

2017-10-01

Bronchoscopy and MDCT are routinely used to assess tracheobronchomalacia (TBM). Recently, dynamic MRI (cine MRI) has been proposed as a radiation-free alternative to MDCT. In this study, we tested cine MRI assessment of airway dynamics during various breathing conditions and compared cine MRI and MDCT measurements in healthy volunteers and patients with suspected TBM. Cine MRI was found to be a technically feasible alternative to MDCT for assessing central airway dynamics.

New developments in imaging: Sonography, cine-CT, MRI

International Nuclear Information System (INIS)

Otto, R.J.; Higgins, C.B.

1987-01-01

The book can be conveniently subdivided into three sections: the first on magnetic resonance imaging the second on cine-computed tomography and the third on advances in ultrasound (US). The MR imaging section includes two chapters: the first on indications for MR in abdominal disease (a cookbook layout of indications for MR imaging versus CT) and the second on MR imaging of the heart. There are also chapters on MR imaging and US in the pelvis, contrast agent principles, and a chapter on imaging renal tumors. The third section, on US, contains chapters on the liver and gastrointenstinal disease, interventional US sonography during neurosurgery, state-of-the-art echocardiography. Doppler flow imaging, contrast media for sonography, endometrial sonography, and high-resolution US in the first trimester. The final chapter is presented as a scientific paper rather than as a chapter in a book and has no illustrations

Las personas mayores a través del cine

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José Ramón Martínez Riera

Full Text Available Resumen: El presente artículo hace un recorrido por las diferentes etapas del envejecimiento y de la vida de las personas mayores a través del cine. El cine es un arte que transmite ideas a través de la narración de historias, mediante imágenes que impactan en el aspecto psicoemocional de las personas. El cine nos sitúa en escenarios donde se muestran las relaciones humanas, en contextos difíciles de reproducir, los cuales nos permiten explorar la esfera de los sentimientos frente a situaciones de salud-enfermedad, de ponerse en lugar del “otro”: de la persona que sueña, padece y sufre, de los profesionales que intervienen, de la familia que convive, cuida, sufre con el enfermo, de los amigos... Y entre esos escenarios, sin duda, se encuentra el proceso de envejecimiento y los diferentes factores que influyen en él. Y sin embargo no suele prestársele excesiva atención a la aportación que el cine ha realizado y realiza como elemento de reflexión, análisis, debate y aprendizaje, más allá del mero entretenimiento en el que muchas veces se enmarca el cine. Pero, ¿cómo ha tratado el cine a las personas mayores? ¿cómo aborda las interrelaciones de las personas mayores con su entorno, su familia, su proceso de salud-enfermedad, sus miedos, sus emociones? ¿Trata igual a las personas mayores con independencia de su género? Y lo que puede ser más interesante, ¿contribuye el cine a mitigar o eliminar los tópicos y estereotipos existentes en el imaginario común en torno a las personas mayores?

21 CFR 892.1620 - Cine or spot fluorographic x-ray camera.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cine or spot fluorographic x-ray camera. 892.1620... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1620 Cine or spot fluorographic x-ray camera. (a) Identification. A cine or spot fluorographic x-ray camera is a device intended to photograph...

Phase Contrast Imaging

International Nuclear Information System (INIS)

Menk, Ralf Hendrik

2008-01-01

All standard (medical) x-ray imaging technologies, rely primarily on the amplitude properties of the incident radiation, and do not depend on its phase. This is unchanged since the discovery by Roentgen that the intensity of an x-ray beam, as measured by the exposure on a film, was related to the relative transmission properties of an object. However, recently various imaging techniques have emerged which depend on the phase of the x-rays as well as the amplitude. Phase becomes important when the beam is coherent and the imaging system is sensitive to interference phenomena. Significant new advances have been made in coherent optic theory and techniques, which now promise phase information in medical imaging. The development of perfect crystal optics and the increasing availability of synchrotron radiation facilities have contributed to a significant increase in the application of phase based imaging in materials and life sciences. Unique source characteristics such as high intensity, monochromaticity, coherence and high collimating provide an ideal source for advanced imaging. Phase contrast imaging has been applied in both projection and computed tomography modes, and recent applications have been made in the field of medical imaging. Due to the underlying principle of X-ray detection conventional image receptors register only intensities of wave fields and not their phases. During the last decade basically five different methods were developed that translate the phase information into intensity variations. These methods are based on measuring the phase shift φ directly (using interference phenomena), the gradient ∇ φ , or the Laplacian ∇ 2 φ. All three methods can be applied to polychromatic X-ray sources keeping in mind that the native source is synchrotron radiation, featuring monochromatic and reasonable coherent X-ray beams. Due to the vast difference in the coefficients that are driven absorption and phase effects (factor 1,000-10,000 in the energy

Phase contrast STEM for thin samples: Integrated differential phase contrast

International Nuclear Information System (INIS)

Lazić, Ivan; Bosch, Eric G.T.; Lazar, Sorin

2016-01-01

It has been known since the 1970s that the movement of the center of mass (COM) of a convergent beam electron diffraction (CBED) pattern is linearly related to the (projected) electrical field in the sample. We re-derive a contrast transfer function (CTF) for a scanning transmission electron microscopy (STEM) imaging technique based on this movement from the point of view of image formation and continue by performing a two-dimensional integration on the two images based on the two components of the COM movement. The resulting integrated COM (iCOM) STEM technique yields a scalar image that is linear in the phase shift caused by the sample and therefore also in the local (projected) electrostatic potential field of a thin sample. We confirm that the differential phase contrast (DPC) STEM technique using a segmented detector with 4 quadrants (4Q) yields a good approximation for the COM movement. Performing a two-dimensional integration, just as for the COM, we obtain an integrated DPC (iDPC) image which is approximately linear in the phase of the sample. Beside deriving the CTFs of iCOM and iDPC, we clearly point out the objects of the two corresponding imaging techniques, and highlight the differences to objects corresponding to COM-, DPC-, and (HA) ADF-STEM. The theory is validated with simulations and we present first experimental results of the iDPC-STEM technique showing its capability for imaging both light and heavy elements with atomic resolution and a good signal to noise ratio (SNR). - Highlights: • First DPC-based atomic resolution images of potential and charge density are obtained. • This is enabled by integration and differentiation of 2D DPC signals, respectively. • Integrated DPC (iDPC) based on 4 quadrant imaging is compared to iCOM imaging. • Noise analysis and comparison with standard STEM imaging modes is provided. • iDPC allows direct imaging of light (C, N, O …) and heavy (Ga, Au …) atoms together.

Phase contrast STEM for thin samples: Integrated differential phase contrast

Energy Technology Data Exchange (ETDEWEB)

Lazić, Ivan, E-mail: ivan.lazic@fei.com; Bosch, Eric G.T.; Lazar, Sorin

2016-01-15

It has been known since the 1970s that the movement of the center of mass (COM) of a convergent beam electron diffraction (CBED) pattern is linearly related to the (projected) electrical field in the sample. We re-derive a contrast transfer function (CTF) for a scanning transmission electron microscopy (STEM) imaging technique based on this movement from the point of view of image formation and continue by performing a two-dimensional integration on the two images based on the two components of the COM movement. The resulting integrated COM (iCOM) STEM technique yields a scalar image that is linear in the phase shift caused by the sample and therefore also in the local (projected) electrostatic potential field of a thin sample. We confirm that the differential phase contrast (DPC) STEM technique using a segmented detector with 4 quadrants (4Q) yields a good approximation for the COM movement. Performing a two-dimensional integration, just as for the COM, we obtain an integrated DPC (iDPC) image which is approximately linear in the phase of the sample. Beside deriving the CTFs of iCOM and iDPC, we clearly point out the objects of the two corresponding imaging techniques, and highlight the differences to objects corresponding to COM-, DPC-, and (HA) ADF-STEM. The theory is validated with simulations and we present first experimental results of the iDPC-STEM technique showing its capability for imaging both light and heavy elements with atomic resolution and a good signal to noise ratio (SNR). - Highlights: • First DPC-based atomic resolution images of potential and charge density are obtained. • This is enabled by integration and differentiation of 2D DPC signals, respectively. • Integrated DPC (iDPC) based on 4 quadrant imaging is compared to iCOM imaging. • Noise analysis and comparison with standard STEM imaging modes is provided. • iDPC allows direct imaging of light (C, N, O …) and heavy (Ga, Au …) atoms together.

Comparisons of images simultaneously documented by digital subtraction coronary arteriography and cine coronary arteriography

International Nuclear Information System (INIS)

Kimura, Koji; Takamiya, Makoto; Yamamoto, Kazuo; Ohta, Mitsushige; Naito, Hiroaki

1988-01-01

Using an angiography apparatus capable of simultaneously processing digital subtraction angiograms and cine angiograms, the diagnostic capabilities of both methods for the coronary arteries (DSCAG and Cine-CAG) were compared. Twenty stenotic lesions of the coronary arteries of 11 patients were evaluated using both modalities. The severity of stenosis using DSCAG with a 512x512x8 bit matrix was semiautomatically measured on the cathode ray tube (CRT) based on enlarged images on the screen of a Vanguard cine projector which were of the same size as those of or 10 times larger than images of Cine-CAG. The negative and positive hard copies of DSCAG images were also compared with those of Cine-CAG. The correlation coefficients of the severity of stenosis by DSCAG and Cine-CAG were as follows: (1) the same size DSCAG images on CRT to Cine-CAG, 0.95, (2) 10 times enlarged DSCAG images on CRT to Cine-CAG, 0.96, and (3) the same size DSCAG images on negative and positive hard copies to Cine-CAG, 0.97. The semiautomatically measured values of 10 times enlarged DSCAG images on CRT and the manually measured values of the same size negative and positive DSCAG images in hard copy closely correlated with the values measured using Cine-CAG. When the liver was superimposed in the long-axis projection, the diagnostic capabilities of DSCAG and Cine-CAG were compared. The materials included 10 left coronary arteriograms and 11 right coronary arteriograms. Diagnostically, DSCAG was more useful than Cine-CAG in the long-axis projection. (author)

Microbubbles as contrast agent for in-line x-ray phase-contrast imaging

International Nuclear Information System (INIS)

Xi Yan; Zhao Jun; Tang Rongbiao; Wang Yujie

2011-01-01

In the present study, we investigated the potential of gas-filled microbubbles as contrast agents for in-line x-ray phase-contrast imaging (PCI) in biomedical applications. When imaging parameters are optimized, the microbubbles function as microlenses that focus the incoming x-rays to form bright spots, which can significantly enhance the image contrast. Since microbubbles have been shown to be safe contrast agents in clinical ultrasonography, this contrast-enhancement procedure for PCI may have promising utility in biomedical applications, especially when the dose of radiation is a serious concern. In this study, we performed both numerical simulations and ex vivo experiments to investigate the formation of the contrast and the effectiveness of microbubbles as contrast agents in PCI.

Image fusion in x-ray differential phase-contrast imaging

Science.gov (United States)

Haas, W.; Polyanskaya, M.; Bayer, F.; Gödel, K.; Hofmann, H.; Rieger, J.; Ritter, A.; Weber, T.; Wucherer, L.; Durst, J.; Michel, T.; Anton, G.; Hornegger, J.

2012-02-01

Phase-contrast imaging is a novel modality in the field of medical X-ray imaging. The pioneer method is the grating-based interferometry which has no special requirements to the X-ray source and object size. Furthermore, it provides three different types of information of an investigated object simultaneously - absorption, differential phase-contrast and dark-field images. Differential phase-contrast and dark-field images represent a completely new information which has not yet been investigated and studied in context of medical imaging. In order to introduce phase-contrast imaging as a new modality into medical environment the resulting information about the object has to be correctly interpreted. The three output images reflect different properties of the same object the main challenge is to combine and visualize these data in such a way that it diminish the information explosion and reduce the complexity of its interpretation. This paper presents an intuitive image fusion approach which allows to operate with grating-based phase-contrast images. It combines information of the three different images and provides a single image. The approach is implemented in a fusion framework which is aimed to support physicians in study and analysis. The framework provides the user with an intuitive graphical user interface allowing to control the fusion process. The example given in this work shows the functionality of the proposed method and the great potential of phase-contrast imaging in medical practice.

Spirometer-controlled cine magnetic resonance imaging used to diagnose tracheobronchomalacia in paediatric patients.

Science.gov (United States)

Ciet, Pierluigi; Wielopolski, Piotr; Manniesing, Rashindra; Lever, Sandra; de Bruijne, Marleen; Morana, Giovanni; Muzzio, Pier Carlo; Lequin, Maarten H; Tiddens, Harm A W M

2014-01-01

Tracheobronchomalacia (TBM) is defined as an excessive collapse of the intrathoracic trachea. Bronchoscopy is the gold standard for diagnosing TBM; however it has major disadvantages, such as general anaesthesia. Cine computed tomography (CT) is a noninvasive alternative used to diagnose TBM, but its use in children is restricted by ionising radiation. Our aim was to evaluate the feasibility of spirometer-controlled cine magnetic resonance imaging (MRI) as an alternative to cine-CT in a retrospective study. 12 children with a mean age (range) of 12 years (7-17 years), suspected of having TBM, underwent cine-MRI. Static scans were acquired at end-inspiration and expiration covering the thorax using a three-dimensional spoiled gradient echo sequence. Three-dimensional dynamic scans were performed covering only the central airways. TBM was defined as a decrease of the trachea or bronchi diameter >50% at end-expiration in the static and dynamic scans. The success rate of the cine-MRI protocol was 92%. Cine-MRI was compared with bronchoscopy or chest CT in seven subjects. TBM was diagnosed by cine-MRI in seven (58%) out of 12 children and was confirmed by bronchoscopy or CT. In four patients, cine-MRI demonstrated tracheal narrowing that was not present in the static scans. Spirometer controlled cine-MRI is a promising technique to assess TBM in children and has the potential to replace bronchoscopy.

Experimental validation of the Wigner distributions theory of phase-contrast imaging

International Nuclear Information System (INIS)

Donnelly, Edwin F.; Price, Ronald R.; Pickens, David R.

2005-01-01

Recently, a new theory of phase-contrast imaging has been proposed by Wu and Liu [Med. Phys. 31, 2378-2384 (2004)]. This theory, based upon Wigner distributions, provides a much stronger foundation for the evaluation of phase-contrast imaging systems than did the prior theories based upon Fresnel-Kirchhoff diffraction theory. In this paper, we compare results of measurements made in our laboratory of phase contrast for different geometries and tube voltages to the predictions of the Wu and Liu model. In our previous publications, we have used an empirical measurement (the edge enhancement index) to parametrize the degree of phase-contrast effects in an image. While the Wu and Liu model itself does not predict image contrast, it does measure the degree of phase contrast that the system can image for a given spatial frequency. We have found that our previously published experimental results relating phase-contrast effects to geometry and x-ray tube voltage are consistent with the predictions of the Wu and Liu model

A four-dimensional motion field atlas of the tongue from tagged and cine magnetic resonance imaging

Science.gov (United States)

Xing, Fangxu; Prince, Jerry L.; Stone, Maureen; Wedeen, Van J.; El Fakhri, Georges; Woo, Jonghye

2017-02-01

Representation of human tongue motion using three-dimensional vector fields over time can be used to better understand tongue function during speech, swallowing, and other lingual behaviors. To characterize the inter-subject variability of the tongue's shape and motion of a population carrying out one of these functions it is desirable to build a statistical model of the four-dimensional (4D) tongue. In this paper, we propose a method to construct a spatio-temporal atlas of tongue motion using magnetic resonance (MR) images acquired from fourteen healthy human subjects. First, cine MR images revealing the anatomical features of the tongue are used to construct a 4D intensity image atlas. Second, tagged MR images acquired to capture internal motion are used to compute a dense motion field at each time frame using a phase-based motion tracking method. Third, motion fields from each subject are pulled back to the cine atlas space using the deformation fields computed during the cine atlas construction. Finally, a spatio-temporal motion field atlas is created to show a sequence of mean motion fields and their inter-subject variation. The quality of the atlas was evaluated by deforming cine images in the atlas space. Comparison between deformed and original cine images showed high correspondence. The proposed method provides a quantitative representation to observe the commonality and variability of the tongue motion field for the first time, and shows potential in evaluation of common properties such as strains and other tensors based on motion fields.

Self-gated fat-suppressed cardiac cine MRI.

Science.gov (United States)

Ingle, R Reeve; Santos, Juan M; Overall, William R; McConnell, Michael V; Hu, Bob S; Nishimura, Dwight G

2015-05-01

To develop a self-gated alternating repetition time balanced steady-state free precession (ATR-SSFP) pulse sequence for fat-suppressed cardiac cine imaging. Cardiac gating is computed retrospectively using acquired magnetic resonance self-gating data, enabling cine imaging without the need for electrocardiogram (ECG) gating. Modification of the slice-select rephasing gradients of an ATR-SSFP sequence enables the acquisition of a one-dimensional self-gating readout during the unused short repetition time (TR). Self-gating readouts are acquired during every TR of segmented, breath-held cardiac scans. A template-matching algorithm is designed to compute cardiac trigger points from the self-gating signals, and these trigger points are used for retrospective cine reconstruction. The proposed approach is compared with ECG-gated ATR-SSFP and balanced steady-state free precession in 10 volunteers and five patients. The difference of ECG and self-gating trigger times has a variability of 13 ± 11 ms (mean ± SD). Qualitative reviewer scoring and ranking indicate no statistically significant differences (P > 0.05) between self-gated and ECG-gated ATR-SSFP images. Quantitative blood-myocardial border sharpness is not significantly different among self-gated ATR-SSFP ( 0.61±0.15 mm -1), ECG-gated ATR-SSFP ( 0.61±0.15 mm -1), or conventional ECG-gated balanced steady-state free precession cine MRI ( 0.59±0.15 mm -1). The proposed self-gated ATR-SSFP sequence enables fat-suppressed cardiac cine imaging at 1.5 T without the need for ECG gating and without decreasing the imaging efficiency of ATR-SSFP. © 2014 Wiley Periodicals, Inc.

Phase-only optical encryption based on the zeroth-order phase-contrast technique

Science.gov (United States)

Pizolato, José Carlos; Neto, Luiz Gonçalves

2009-09-01

A phase-only encryption/decryption scheme with the readout based on the zeroth-order phase-contrast technique (ZOPCT), without the use of a phase-changing plate on the Fourier plane of an optical system based on the 4f optical correlator, is proposed. The encryption of a gray-level image is achieved by multiplying the phase distribution obtained directly from the gray-level image by a random phase distribution. The robustness of the encoding is assured by the nonlinearity intrinsic to the proposed phase-contrast method and the random phase distribution used in the encryption process. The experimental system has been implemented with liquid-crystal spatial modulators to generate phase-encrypted masks and a decrypting key. The advantage of this method is the easy scheme to recover the gray-level information from the decrypted phase-only mask applying the ZOPCT. An analysis of this decryption method was performed against brute force attacks.

Reconstruction methods for phase-contrast tomography

Energy Technology Data Exchange (ETDEWEB)

Raven, C.

1997-02-01

Phase contrast imaging with coherent x-rays can be distinguished in outline imaging and holography, depending on the wavelength {lambda}, the object size d and the object-to-detector distance r. When r << d{sup 2}{lambda}, phase contrast occurs only in regions where the refractive index fastly changes, i.e. at interfaces and edges in the sample. With increasing object-to-detector distance we come in the area of holographic imaging. The image contrast outside the shadow region of the object is due to interference of the direct, undiffracted beam and a beam diffracted by the object, or, in terms of holography, the interference of a reference wave with the object wave. Both, outline imaging and holography, offer the possibility to obtain three dimensional information of the sample in conjunction with a tomographic technique. But the data treatment and the kind of information one can obtain from the reconstruction is different.

Chest wall invasion by bronchogenic carcinoma. Evaluation with Cine-MRI

International Nuclear Information System (INIS)

Nawano, Shigeru; Murakami, Kohji; Ohnuma, Hiroshi; Iwata, Ryoko; Hayashi, Takayuki; Moriyama, Noriyuki; Nishiwaki, Yutaka; Nagai, Kanji

1996-01-01

With the view of examining possible chest wall invasion of bronchogenic carcinoma, Cine-MRI was performed on 22 such cases. These cases were suspected of having above chest wall invasion by CT and their histopathological findings were obtained in surgery. The judgment of the chest wall invasion by Cine-CT was made such that non-moving up and down of the tumor with respiration involves its invasion, moving of the tumor without any up-and-down movement suspects its invasion and moving up and down of the tumor with respiration involves no invasion. The chest wall invasion was observed in 5 of 7 cases of invasion judged by Cine-MRI. For 2 false-positive cases, the histopathological findings presumed that tumor cells disappeared from the chest wall invaded region as the result of preoperative chemotherapy. The above invasion was observed in 1 of 4 cases suspected of possible invasion. Correct diagnosis was formed of 11 cases judged invasion-free by Cine-MRI. The above results suggested Cine-MRI to be useful for diagnosis of chest wall invasion of bronchogenic carcinoma. (author)

Enhanced renal image contrast by ethanol fixation in phase-contrast X-ray computed tomography.

Science.gov (United States)

Shirai, Ryota; Kunii, Takuya; Yoneyama, Akio; Ooizumi, Takahito; Maruyama, Hiroko; Lwin, Thet Thet; Hyodo, Kazuyuki; Takeda, Tohoru

2014-07-01

Phase-contrast X-ray imaging using a crystal X-ray interferometer can depict the fine structures of biological objects without the use of a contrast agent. To obtain higher image contrast, fixation techniques have been examined with 100% ethanol and the commonly used 10% formalin, since ethanol causes increased density differences against background due to its physical properties and greater dehydration of soft tissue. Histological comparison was also performed. A phase-contrast X-ray system was used, fitted with a two-crystal X-ray interferometer at 35 keV X-ray energy. Fine structures, including cortex, tubules in the medulla, and the vessels of ethanol-fixed kidney could be visualized more clearly than that of formalin-fixed tissues. In the optical microscopic images, shrinkage of soft tissue and decreased luminal space were observed in ethanol-fixed kidney; and this change was significantly shown in the cortex and outer stripe of the outer medulla. The ethanol fixation technique enhances image contrast by approximately 2.7-3.2 times in the cortex and the outer stripe of the outer medulla; the effect of shrinkage and the physical effect of ethanol cause an increment of approximately 78% and 22%, respectively. Thus, the ethanol-fixation technique enables the image contrast to be enhanced in phase-contrast X-ray imaging.

Feasibility of vocal fold abduction and adduction assessment using cine-MRI.

Science.gov (United States)

Baki, Marina Mat; Menys, Alex; Atkinson, David; Bassett, Paul; Morley, Simon; Beale, Timothy; Sandhu, Guri; Naduvilethil, Georgekutty; Stevenson, Nicola; Birchall, Martin A; Punwani, Shonit

2017-02-01

Determine feasibility of vocal fold (VF) abduction and adduction assessment by cine magnetic resonance imaging (cine-MRI) METHODS: Cine-MRI of the VF was performed on five healthy and nine unilateral VF paralysis (UVFP) participants using an axial gradient echo acquisition with temporal resolution of 0.7 s. VFs were continuously imaged with cine-MRI during a 10-s period of quiet respiration and phonation. Scanning was repeated twice within an individual session and then once again at a 1-week interval. Asymmetry of VF position during phonation (VF phonation asymmetry, VFPa) and respiration (VF respiration asymmetry, VFRa) was determined. Percentage reduction in total glottal area between respiration and phonation (VF abduction potential, VFAP) was derived to measure overall mobility. An un-paired t-test was used to compare differences between groups. Intra-session, inter-session and inter-reader repeatability of the quantitative metrics was evaluated using intraclass correlation coefficient (ICC). VF position asymmetry (VFPa and VFRa) was greater (p=0.012; p=0.001) and overall mobility (VFAP) was lower (p=0.008) in UVFP patients compared with healthy participants. ICC of repeatability of all metrics was good, ranged from 0.82 to 0.95 except for the inter-session VFPa (0.44). Cine-MRI is feasible for assessing VF abduction and adduction. Derived quantitative metrics have good repeatability. • Cine-MRI is used to assess vocal folds (VFs) mobility: abduction and adduction. • New quantitative metrics are derived from VF position and abduction potential. • Cine-MRI able to depict the difference between normal and abnormal VF mobility. • Cine-MRI derived quantitative metrics have good repeatability.

X-ray phase-contrast tomosynthesis for improved breast tissue discrimination

International Nuclear Information System (INIS)

Schleede, Simone; Bech, Martin; Grandl, Susanne; Sztrókay, Aniko; Herzen, Julia; Mayr, Doris; Stockmar, Marco; Potdevin, Guillaume

2014-01-01

Purpose: Attenuation-based tomosynthesis has proven to successfully resolve the glandular tissue overlap present in mammography. However, the ability of tomosynthesis to differentiate tumorous and glandular tissue remains limited, due to the small differences in X-ray attenuation in breast tissue. One possibility to overcome this limitation and to further increase the diagnostic value of tomosynthesis exams, is the application of recently developed grating-based phase-contrast methods, which provide complementary information on the phase shift and the local scattering power of the sample. In this study, we report on first phase-contrast breast tomosynthesis results of a mastectomy sample slice with an invasive ductal carcinoma. Material and methods: A slice of a mastectomy sample with histologically proven invasive ductal cancer was imaged at the synchrotron radiation source ESRF (Grenoble, France). We used a two-grating interferometer setup at the ninth fractional Talbot distance and with an X-ray energy of 23 keV. In grating interferometry absorption, differential phase, and scattering images are recorded simultaneously. The tomosynthesis scan comprises 61 projections. Multimodal tomosynthesis results were reconstructed using a standard filtered back-projection approach. Our findings are supported by a comparison of tomographic views to histopathology. Results: Phase-contrast tomosynthesis combines the advantage of improved soft-tissue discrimination in phase-contrast imaging with the ability of tomosynthesis to provide a third dimension so that improved feature visibility is not hampered by superposition artifacts. Our results indicate superior diagnostic value due to the depth resolution supplied in tomosynthesis imaging; a region of necrotic tissue that is obscured in a projection image can clearly be depicted in one single tomosynthesis slice. Compared to absorption tomosynthesis alone, soft tissue contrast is significantly enhanced in phase-contrast

X-ray phase-contrast tomosynthesis for improved breast tissue discrimination.

Science.gov (United States)

Schleede, Simone; Bech, Martin; Grandl, Susanne; Sztrókay, Aniko; Herzen, Julia; Mayr, Doris; Stockmar, Marco; Potdevin, Guillaume; Zanette, Irene; Rack, Alexander; Weitkamp, Timm; Pfeiffer, Franz

2014-03-01

Attenuation-based tomosynthesis has proven to successfully resolve the glandular tissue overlap present in mammography. However, the ability of tomosynthesis to differentiate tumorous and glandular tissue remains limited, due to the small differences in X-ray attenuation in breast tissue. One possibility to overcome this limitation and to further increase the diagnostic value of tomosynthesis exams, is the application of recently developed grating-based phase-contrast methods, which provide complementary information on the phase shift and the local scattering power of the sample. In this study, we report on first phase-contrast breast tomosynthesis results of a mastectomy sample slice with an invasive ductal carcinoma. A slice of a mastectomy sample with histologically proven invasive ductal cancer was imaged at the synchrotron radiation source ESRF (Grenoble, France). We used a two-grating interferometer setup at the ninth fractional Talbot distance and with an X-ray energy of 23 keV. In grating interferometry absorption, differential phase, and scattering images are recorded simultaneously. The tomosynthesis scan comprises 61 projections. Multimodal tomosynthesis results were reconstructed using a standard filtered back-projection approach. Our findings are supported by a comparison of tomographic views to histopathology. Phase-contrast tomosynthesis combines the advantage of improved soft-tissue discrimination in phase-contrast imaging with the ability of tomosynthesis to provide a third dimension so that improved feature visibility is not hampered by superposition artifacts. Our results indicate superior diagnostic value due to the depth resolution supplied in tomosynthesis imaging; a region of necrotic tissue that is obscured in a projection image can clearly be depicted in one single tomosynthesis slice. Compared to absorption tomosynthesis alone, soft tissue contrast is significantly enhanced in phase-contrast tomosynthesis views, where fibrous structures

WE-G-BRD-06: Volumetric Cine MRI (VC-MRI) Estimated Based On Prior Knowledge for On-Board Target Localization

International Nuclear Information System (INIS)

Harris, W; Yin, F; Cai, J; Zhang, Y; Ren, L

2015-01-01

Purpose: To develop a technique to generate on-board VC-MRI using patient prior 4D-MRI, motion modeling and on-board 2D-cine MRI for real-time 3D target verification of liver and lung radiotherapy. Methods: The end-expiration phase images of a 4D-MRI acquired during patient simulation are used as patient prior images. Principal component analysis (PCA) is used to extract 3 major respiratory deformation patterns from the Deformation Field Maps (DFMs) generated between end-expiration phase and all other phases. On-board 2D-cine MRI images are acquired in the axial view. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI at the end-expiration phase. The DFM is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by matching the corresponding 2D slice of the estimated VC-MRI with the acquired single 2D-cine MRI. The method was evaluated using both XCAT (a computerized patient model) simulation of lung cancer patients and MRI data from a real liver cancer patient. The 3D-MRI at every phase except end-expiration phase was used to simulate the ground-truth on-board VC-MRI at different instances, and the center-tumor slice was selected to simulate the on-board 2D-cine images. Results: Image subtraction of ground truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground truth with prior image. Excellent agreement between profiles was achieved. The normalized cross correlation coefficients between the estimated and ground-truth in the axial, coronal and sagittal views for each time step were >= 0.982, 0.905, 0.961 for XCAT data and >= 0.998, 0.911, 0.9541 for patient data. For XCAT data, the maximum-Volume-Percent-Difference between ground-truth and estimated tumor volumes was 1.6% and the maximum-Center-of-Mass-Shift was 0.9 mm. Conclusion: Preliminary studies demonstrated the feasibility to estimate real-time VC-MRI for on

WE-G-BRD-06: Volumetric Cine MRI (VC-MRI) Estimated Based On Prior Knowledge for On-Board Target Localization

Energy Technology Data Exchange (ETDEWEB)

Harris, W; Yin, F; Cai, J; Zhang, Y; Ren, L [Duke University Medical Center, Durham, NC (United States)

2015-06-15

Purpose: To develop a technique to generate on-board VC-MRI using patient prior 4D-MRI, motion modeling and on-board 2D-cine MRI for real-time 3D target verification of liver and lung radiotherapy. Methods: The end-expiration phase images of a 4D-MRI acquired during patient simulation are used as patient prior images. Principal component analysis (PCA) is used to extract 3 major respiratory deformation patterns from the Deformation Field Maps (DFMs) generated between end-expiration phase and all other phases. On-board 2D-cine MRI images are acquired in the axial view. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI at the end-expiration phase. The DFM is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by matching the corresponding 2D slice of the estimated VC-MRI with the acquired single 2D-cine MRI. The method was evaluated using both XCAT (a computerized patient model) simulation of lung cancer patients and MRI data from a real liver cancer patient. The 3D-MRI at every phase except end-expiration phase was used to simulate the ground-truth on-board VC-MRI at different instances, and the center-tumor slice was selected to simulate the on-board 2D-cine images. Results: Image subtraction of ground truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground truth with prior image. Excellent agreement between profiles was achieved. The normalized cross correlation coefficients between the estimated and ground-truth in the axial, coronal and sagittal views for each time step were >= 0.982, 0.905, 0.961 for XCAT data and >= 0.998, 0.911, 0.9541 for patient data. For XCAT data, the maximum-Volume-Percent-Difference between ground-truth and estimated tumor volumes was 1.6% and the maximum-Center-of-Mass-Shift was 0.9 mm. Conclusion: Preliminary studies demonstrated the feasibility to estimate real-time VC-MRI for on

Direct comparison of high‐temporal‐resolution CINE MRI with Doppler ultrasound for assessment of diastolic dysfunction in mice

Science.gov (United States)

Price, Anthony N.; Jackson, Laurence H.; Taylor, Valerie; David, Anna L.; Lythgoe, Mark F.; Stuckey, Daniel J.

2017-01-01

Diastolic dysfunction is a sensitive early indicator of heart failure and can provide additional data to conventional measures of systolic function. Transmitral Doppler ultrasound, which measures the one‐dimensional flow of blood through the mitral valve, is currently the preferred method for the measurement of diastolic function, but the measurement of the left ventricular volume changes using high‐temporal‐resolution cinematic magnetic resonance imaging (CINE MRI) is an alternative approach which is emerging as a potentially more robust and user‐independent technique. Here, we investigated the performance of high‐temporal‐resolution CINE MRI and compared it with ultrasound for the detection of diastolic dysfunction in a mouse model of myocardial infarction. An in‐house, high‐temporal‐resolution, retrospectively gated CINE sequence was developed with a temporal resolution of 1 ms. Diastolic function in mice was assessed using a custom‐made, open‐source reconstruction package. Early (E) and late (A) left ventricular filling phases were easily identifiable, and these measurements were compared directly with high‐frequency, pulsed‐wave, Doppler ultrasound measurements of mitral valve inflow. A repeatability study established that high‐temporal‐resolution CINE MRI and Doppler ultrasound showed comparable accuracy when measuring E/A in normal control mice. However, when applied in a mouse model of myocardial infarction, high‐temporal‐resolution CINE MRI indicated diastolic heart failure (E/A = 0.94 ± 0.11), whereas ultrasound falsely detected normal cardiac function (E/A = 1.21 ± 0.11). The addition of high‐temporal‐resolution CINE MRI to preclinical imaging studies enhances the library of sequences available to cardiac researchers and potentially identifies diastolic heart failure early in disease progression. PMID:28643891

Left Ventricular Function Evaluation on a 3T MR Scanner with Parallel RF Transmission Technique: Prospective Comparison of Cine Sequences Acquired before and after Gadolinium Injection.

Science.gov (United States)

Caspar, Thibault; Schultz, Anthony; Schaeffer, Mickaël; Labani, Aïssam; Jeung, Mi-Young; Jurgens, Paul Thomas; El Ghannudi, Soraya; Roy, Catherine; Ohana, Mickaël

To compare cine MR b-TFE sequences acquired before and after gadolinium injection, on a 3T scanner with a parallel RF transmission technique in order to potentially improve scanning time efficiency when evaluating LV function. 25 consecutive patients scheduled for a cardiac MRI were prospectively included and had their b-TFE cine sequences acquired before and right after gadobutrol injection. Images were assessed qualitatively (overall image quality, LV edge sharpness, artifacts and LV wall motion) and quantitatively with measurement of LVEF, LV mass, and telediastolic volume and contrast-to-noise ratio (CNR) between the myocardium and the cardiac chamber. Statistical analysis was conducted using a Bayesian paradigm. No difference was found before or after injection for the LVEF, LV mass and telediastolic volume evaluations. Overall image quality and CNR were significantly lower after injection (estimated coefficient cine after > cine before gadolinium: -1.75 CI = [-3.78;-0.0305], prob(coef>0) = 0% and -0.23 CI = [-0.49;0.04], prob(coef>0) = 4%) respectively), but this decrease did not affect the visual assessment of LV wall motion (cine after > cine before gadolinium: -1.46 CI = [-4.72;1.13], prob(coef>0) = 15%). In 3T cardiac MRI acquired with parallel RF transmission technique, qualitative and quantitative assessment of LV function can reliably be performed with cine sequences acquired after gadolinium injection, despite a significant decrease in the CNR and the overall image quality.

Spirometer-controlled cine magnetic resonance imaging to diagnose tracheobronchomalacia in pediatric patients

DEFF Research Database (Denmark)

Ciet, Pierluigi; Wielopolski, Piotr; Manniesing, Rashindra

2014-01-01

is restricted by ionizing radiation. Our aim was to evaluate the feasibility of spirometer-controlled cine-MRI as alternative to cine-CT in a retrospective study.12 children (mean 12 years, range 7-17), suspected to have TBM, underwent cine-MRI. Static scans were acquired at end-inspiration and expiration......Tracheobronchomalacia (TBM) is defined as an excessive collapse of the intrathoracic trachea. Bronchoscopy is the gold standard to diagnose TBM, but bronchoscopy has major disadvantages, such as general anaesthesia. Cine-CT is a non-invasive alternative to diagnose TBM, but its use in children...

Entre la Historia y el Cine

Directory of Open Access Journals (Sweden)

Luisa Fernanda Acosta

1995-01-01

Full Text Available Este trabajo se propone aplicar al cine el concepto de «fuente histórica». El uso de medios de comunicación como el cine está íntimamente relacionado con las necesidades y posibilidades de una sociedad, lo que implica una relación muy cercana entre el desarrollo social y económico de una comunidad, y los mecanismos que ella genera como canales de expresión y comunicación. El cine, conjugación de imagen, sonido y movimiento se convierte para la sociedades contemporáneas en una gran alternativa como fuente histórica, que provee al investigador ópticas diferentes de una realidad ya explorada. Un gesto, una mirada, un plano, una secuencia, se traducen en frases y párrafos, que generan una versión diferente de la historia, una redacción que se lee en imágenes y que narra otro punto de vista, un relato oculto que tiene todo por contar.

Pilot experimental study on continual spectrum thermal neutron in-line phase contrast radiography

International Nuclear Information System (INIS)

Tang Bin; Huo Heyong; Wu Yang

2009-01-01

The in-line phase contrast radiography is one of phase contrast imaging methods. The neutron in-line phase contrast is developed with X-rays phase contrast radiography. In the paper, the principle of in-line phase contrast is introduced briefly and the experimental result of thermal neutron in-line contrast at SPRR-300 is analysed. It shows that thermal neutron can be used as in-line phase contrast radiography and enhances the edge of some sample in radiography and complements the disadvantage of conventional neutron radiography. (authors)

Craniocaudal Safety Margin Calculation Based on Interfractional Changes in Tumor Motion in Lung SBRT Assessed With an EPID in Cine Mode

International Nuclear Information System (INIS)

Ueda, Yoshihiro; Miyazaki, Masayoshi; Nishiyama, Kinji; Suzuki, Osamu; Tsujii, Katsutomo; Miyagi, Ken

2012-01-01

Purpose: To evaluate setup error and interfractional changes in tumor motion magnitude using an electric portal imaging device in cine mode (EPID cine) during the course of stereotactic body radiation therapy (SBRT) for non–small-cell lung cancer (NSCLC) and to calculate margins to compensate for these variations. Materials and Methods: Subjects were 28 patients with Stage I NSCLC who underwent SBRT. Respiratory-correlated four-dimensional computed tomography (4D-CT) at simulation was binned into 10 respiratory phases, which provided average intensity projection CT data sets (AIP). On 4D-CT, peak-to-peak motion of the tumor (M-4DCT) in the craniocaudal direction was assessed and the tumor center (mean tumor position [MTP]) of the AIP (MTP-4DCT) was determined. At treatment, the tumor on cone beam CT was registered to that on AIP for patient setup. During three sessions of irradiation, peak-to-peak motion of the tumor (M-cine) and the mean tumor position (MTP-cine) were obtained using EPID cine and in-house software. Based on changes in tumor motion magnitude (∆M) and patient setup error (∆MTP), defined as differences between M-4DCT and M-cine and between MTP-4DCT and MTP-cine, a margin to compensate for these variations was calculated with Stroom’s formula. Results: The means (±standard deviation: SD) of M-4DCT and M-cine were 3.1 (±3.4) and 4.0 (±3.6) mm, respectively. The means (±SD) of ∆M and ∆MTP were 0.9 (±1.3) and 0.2 (±2.4) mm, respectively. Internal target volume-planning target volume (ITV-PTV) margins to compensate for ∆M, ∆MTP, and both combined were 3.7, 5.2, and 6.4 mm, respectively. Conclusion: EPID cine is a useful modality for assessing interfractional variations of tumor motion. The ITV-PTV margins to compensate for these variations can be calculated.

MUJER Y CINE EN AMÉRICA LATINA: PROYECTANDO UNA VISIÓN ALTERNATIVA DE LA NACIÓN

Directory of Open Access Journals (Sweden)

Rosa-Linda Fregoso

2016-01-01

Full Text Available Al explorar la relación entre cine de mujeres y cines latinoamericanos, este artículo interroga las categorías de cine nacional, cine latinoamericano y cine de mujeres con el fin de superar lógicas geopolíticas, de idiomas, colonialidad, y las lógicas industriales del mercado que han creado esas categorías. Partiendo de interrogantes como qué modelo de análisis feminista del cine es adecuado para articular las perspectivas de mujeres en las nuevas formaciones del cine mundial, propongo la utilidad del discurso de la interseccionalidad para un análisis de cine de mujeres que presente una visión alternativa de la nación.

Phase contrast imaging with coherent high energy X-rays

Energy Technology Data Exchange (ETDEWEB)

Snigireva, I. [ESRF, Grenoble (France)

1997-02-01

X-ray imaging concern high energy domain (>6 keV) like a contact radiography, projection microscopy and tomography is used for many years to discern the features of the internal structure non destructively in material science, medicine and biology. In so doing the main contrast formation is absorption that makes some limitations for imaging of the light density materials and what is more the resolution of these techniques is not better than 10-100 {mu}m. It was turned out that there is now way in which to overcome 1{mu}m or even sub-{mu}m resolution limit except phase contrast imaging. It is well known in optics that the phase contrast is realised when interference between reference wave front and transmitted through the sample take place. Examples of this imaging are: phase contrast microscopy suggested by Zernike and Gabor (in-line) holography. Both of this techniques: phase contrast x-ray microscopy and holography are successfully progressing now in soft x-ray region. For imaging in the hard X-rays to enhance the contrast and to be able to resolve phase variations across the beam the high degree of the time and more importantly spatial coherence is needed. Because of this it was reasonable that the perfect crystal optics was involved like Bonse-Hart interferometry, double-crystal and even triple-crystal set-up using Laue and Bragg geometry with asymmetrically cut crystals.

Diffractive generalized phase contrast for adaptive phase imaging and optical security

DEFF Research Database (Denmark)

Palima, Darwin; Glückstad, Jesper

2012-01-01

We analyze the properties of Generalized Phase Contrast (GPC) when the input phase modulation is implemented using diffractive gratings. In GPC applications for patterned illumination, the use of a dynamic diffractive optical element for encoding the GPC input phase allows for onthe- fly optimiza...... security applications and can be used to create phasebased information channels for enhanced information security....

Generalised phase contrast: microscopy, manipulation and more

DEFF Research Database (Denmark)

Palima, Darwin; Glückstad, Jesper

2010-01-01

Generalised phase contrast (GPC) not only leads to more accurate phase imaging beyond thin biological samples, but serves as an enabling framework in developing tools over a wide spectrum of contemporary applications in optics and photonics, including optical trapping and micromanipulation, optic...

El cine en el cine: Los abrazos rotos (Pedro Almodóvar, 2009

Directory of Open Access Journals (Sweden)

Pedro Poyato

2012-10-01

Full Text Available El cine en el cine, tema recurrente en la filmografía de Pedro Almodóvar, protagoniza también Los abrazos rotos, película que contiene en su interior otra titulada Chicas y maletas. Pero las imágenes de esta segunda película, trasunto de otra anterior del propio Almodóvar, Mujeres al borde un ataque de nervios, coexisten con las de un documental sobre su rodaje. El resultado es una proliferación de imágenes segundas que, incorporadas según una estructura en abismo, el filme va a conjugar de múltiples y variadas maneras. El presente trabajo trata de dar cuenta de la génesis, funcionamiento y declinación de estas imágenes segundas y de los sentidos que de ello emanan.

Cine MRI of the thorax in patients with pectus excavatum

International Nuclear Information System (INIS)

Herrmann, K.A.; Zech, C.J.; Schoenberg, S.O.; Reiser, M.F.; Strauss, T.; Hatz, R.

2006-01-01

Morphologic and dynamic assessment of respiratory chest kinetics was performed in patients with pectus excavatum deformity (PE) using dynamic MRI: cine MRI. Seven consecutive patients with PE (aged 20.3 years±4.0) and ten healthy volunteers of comparable age underwent real-time cine MRI of the chest during breathing on a 1.5 T MR scanner (Magnetom Sonata, Siemens Medical Systems, Erlangen, Germany) using a standard phased array body coil and a half-Fourier single-shot turbo spin echo sequence (HASTE) for dynamic imaging. During deep inspiration and expiration, single-shot sequences were performed in one slice level over 20 s at a frequency of 1 image/s covering the entire thoracic cage in three orientations. Morphology and chest kinetics in patients with PE were analyzed and compared with normal values, and typical patterns of chest kinetics were noted. Three different types of chest morphology in PE were identified: (1) the generally flattened thoracic cage, (2) the ''tilted'' sternum, and (3) the focally deepened sternum. Three patterns of motion correspond to these morphological types: (1) elevation of the sternum and the anterior thoracic wall, (2) angulated elevation of the parasternal rib cage with persistent deepening of the sternum resembling a ''wing beat'' movement, and (3) increased diaphragmatic movements with limited chest wall dynamics. Cine MRI is an adequate radiation-free diagnostic modality for the dynamic imaging of both chest morphology and chest wall kinetics in patients with PE. The pectus severity index can easily be determined and three typical movement patterns of chest wall kinetics identified. (orig.) [de

An integrated model-driven method for in-treatment upper airway motion tracking using cine MRI in head and neck radiation therapy.

Science.gov (United States)

Li, Hua; Chen, Hsin-Chen; Dolly, Steven; Li, Harold; Fischer-Valuck, Benjamin; Victoria, James; Dempsey, James; Ruan, Su; Anastasio, Mark; Mazur, Thomas; Gach, Michael; Kashani, Rojano; Green, Olga; Rodriguez, Vivian; Gay, Hiram; Thorstad, Wade; Mutic, Sasa

2016-08-01

For the first time, MRI-guided radiation therapy systems can acquire cine images to dynamically monitor in-treatment internal organ motion. However, the complex head and neck (H&N) structures and low-contrast/resolution of on-board cine MRI images make automatic motion tracking a very challenging task. In this study, the authors proposed an integrated model-driven method to automatically track the in-treatment motion of the H&N upper airway, a complex and highly deformable region wherein internal motion often occurs in an either voluntary or involuntary manner, from cine MRI images for the analysis of H&N motion patterns. Considering the complex H&N structures and ensuring automatic and robust upper airway motion tracking, the authors firstly built a set of linked statistical shapes (including face, face-jaw, and face-jaw-palate) using principal component analysis from clinically approved contours delineated on a set of training data. The linked statistical shapes integrate explicit landmarks and implicit shape representation. Then, a hierarchical model-fitting algorithm was developed to align the linked shapes on the first image frame of a to-be-tracked cine sequence and to localize the upper airway region. Finally, a multifeature level set contour propagation scheme was performed to identify the upper airway shape change, frame-by-frame, on the entire image sequence. The multifeature fitting energy, including the information of intensity variations, edge saliency, curve geometry, and temporal shape continuity, was minimized to capture the details of moving airway boundaries. Sagittal cine MR image sequences acquired from three H&N cancer patients were utilized to demonstrate the performance of the proposed motion tracking method. The tracking accuracy was validated by comparing the results to the average of two manual delineations in 50 randomly selected cine image frames from each patient. The resulting average dice similarity coefficient (93.28%  ±  1

A Technique for Generating Volumetric Cine MRI (VC-MRI)

Science.gov (United States)

Harris, Wendy; Ren, Lei; Cai, Jing; Zhang, You; Chang, Zheng; Yin, Fang-Fang

2016-01-01

Purpose To develop a technique to generate on-board volumetric-cine MRI (VC-MRI) using patient prior images, motion modeling and on-board 2D-cine MRI. Methods One phase of a 4D-MRI acquired during patient simulation is used as patient prior images. 3 major respiratory deformation patterns of the patient are extracted from 4D-MRI based on principal-component-analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2D-cine MRI. The method was evaluated using both XCAT simulation of lung cancer patients and MRI data from four real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using Volume-Percent-Difference(VPD), Center-of-Mass-Shift(COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest(ROI) selection, patient breathing pattern change and noise on the estimation accuracy were also evaluated. Results Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was on average 8.43±1.52% and the COMS was on average 0.93±0.58mm across all time-steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against noise levels up to SNR=20. For patient data, average tracking errors were less than 2 mm in all directions for all patients. Conclusions Preliminary studies demonstrated the

A Technique for Generating Volumetric Cine-Magnetic Resonance Imaging

International Nuclear Information System (INIS)

Harris, Wendy; Ren, Lei; Cai, Jing; Zhang, You; Chang, Zheng; Yin, Fang-Fang

2016-01-01

Purpose: The purpose of this study was to develop a techique to generate on-board volumetric cine-magnetic resonance imaging (VC-MRI) using patient prior images, motion modeling, and on-board 2-dimensional cine MRI. Methods and Materials: One phase of a 4-dimensional MRI acquired during patient simulation is used as patient prior images. Three major respiratory deformation patterns of the patient are extracted from 4-dimensional MRI based on principal-component analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2-dimensional cine MRI. The method was evaluated using both digital extended-cardiac torso (XCAT) simulation of lung cancer patients and MRI data from 4 real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using volume-percent-difference (VPD), center-of-mass-shift (COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest (ROI) selection, patient breathing pattern change, and noise on the estimation accuracy were also evaluated. Results: Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between normalized profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was, on average, 8.43 ± 1.52% and the COMS was, on average, 0.93 ± 0.58 mm across all time steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against

A Technique for Generating Volumetric Cine-Magnetic Resonance Imaging

Energy Technology Data Exchange (ETDEWEB)

Harris, Wendy [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Ren, Lei, E-mail: lei.ren@duke.edu [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Cai, Jing [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Zhang, You [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Chang, Zheng; Yin, Fang-Fang [Medical Physics Graduate Program, Duke University, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)

2016-06-01

Purpose: The purpose of this study was to develop a techique to generate on-board volumetric cine-magnetic resonance imaging (VC-MRI) using patient prior images, motion modeling, and on-board 2-dimensional cine MRI. Methods and Materials: One phase of a 4-dimensional MRI acquired during patient simulation is used as patient prior images. Three major respiratory deformation patterns of the patient are extracted from 4-dimensional MRI based on principal-component analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2-dimensional cine MRI. The method was evaluated using both digital extended-cardiac torso (XCAT) simulation of lung cancer patients and MRI data from 4 real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using volume-percent-difference (VPD), center-of-mass-shift (COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest (ROI) selection, patient breathing pattern change, and noise on the estimation accuracy were also evaluated. Results: Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between normalized profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was, on average, 8.43 ± 1.52% and the COMS was, on average, 0.93 ± 0.58 mm across all time steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against

Fundamental Tongue Motions for Trumpet Playing: A Study Using Cine Magnetic Resonance Imaging (Cine MRI).

Science.gov (United States)

Furuhashi, Hiroko; Chikui, Toru; Inadomi, Daisuke; Shiraishi, Tomoko; Yoshiura, Kazunori

2017-12-01

Though the motions of structures outside the mouth in trumpet performance have been reported, the dynamics of intraoral structures remain unelucidated. This study explored the tongue's movement in trumpet playing using cine magnetic resonance imaging (cine MRI) and demonstrated the effects of intraoral anatomical structures on changes in pitch and dynamics. Cine MRI was applied to 18 trumpet players, who were divided into two groups (7 beginner, 11 advanced) based on their ability to play a certain high note. They were instructed to play a custom-made MRI-compatible simulated trumpet. Pitch-change tasks and dynamics-change tasks were assigned. The positions of the anatomical points and intraoral areas were identified on outlined images, and the changes associated with each task were evaluated. A forward and upward projection of the tongue was observed in the production of higher pitches, and there were no significant differences in all areas. In louder dynamics, a backward and downward bending of the tongue occurred, the tongue area became smaller (pcine MRI that certain tongue movements were associated with each task. Tongue protrusion in the production of higher pitch and bending in louder dynamics can be rationalized using acoustics theory and the movements of anatomical structures. These findings seem to be consistent regardless of the player's proficiency.

Subtraction MR venography acquired from time-resolved contrast-enhanced MR angiography: Comparison with phase-contrast MR venography and single-phase contrast-enhanced MR venography

International Nuclear Information System (INIS)

Jang, Jin Hee; Kim, Bum Soo; KIm, Bom Yi; Choi, Hyun Seok; Jung, So Lyung; Ahn, Kook Jin; Sung, Ji Kyeong

2015-01-01

To evaluate the image characteristics of subtraction magnetic resonance venography (SMRV) from time-resolved contrast-enhanced MR angiography (TRMRA) compared with phase-contrast MR venography (PCMRV) and single-phase contrast-enhanced MR venography (CEMRV). Twenty-one patients who underwent brain MR venography (MRV) using standard protocols (PCMRV, CEMRV, and TRMRA) were included. SMRV was made by subtracting the arterial phase data from the venous phase data in TRMRA. Co-registration and subtraction of the two volume data was done using commercially available software. Image quality and the degree of arterial contamination of the three MRVs were compared. In the three MRVs, 19 pre-defined venous structures (14 dural sinuses and 5 cerebral veins) were evaluated. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the three MRVs were also compared. Single-phase contrast-enhanced MR venography showed better image quality (median score 4 in both reviewers) than did the other two MRVs (p < 0.001), whereas SMRV (median score 3 in both reviewers) and PCMRV (median score 3 in both reviewers) had similar image quality (p ≥ 0.951). SMRV (median score 0 in both reviewers) suppressed arterial signal better than did the other MRVs (median score 1 in CEMRV, median score 2 in PCMRV, both reviewers) (p < 0.001). The dural sinus score of SMRV (median and interquartile range [IQR] 48, 43-50 for reviewer 1, 47, 43-49 for reviewer 2) was significantly higher than for PCMRV (median and IQR 31, 25-34 for reviewer 1, 30, 23-32 for reviewer 2) (p < 0.01) and did not differ from that of CEMRV (median and IQR 50, 47-52 for reviewer 1, 49, 45-51 for reviewer 2) (p = 0.146 in reviewer 1 and 0.123 in reviewer 2). The SNR and CNR of SMRV (median and IQR 104.5, 83.1-121.2 and 104.1, 74.9-120.5, respectively) were between those of CEMRV (median and IQR 150.3, 111-182.6 and 148.4, 108-178.2) and PCMRV (median and IQR 59.4, 49.2-74.9 and 53.6, 43.8-69.2). Subtraction magnetic

Free-breathing black-blood CINE fast-spin echo imaging for measuring abdominal aortic wall distensibility: a feasibility study

Science.gov (United States)

Lin, Jyh-Miin; Patterson, Andrew J.; Chao, Tzu-Cheng; Zhu, Chengcheng; Chang, Hing-Chiu; Mendes, Jason; Chung, Hsiao-Wen; Gillard, Jonathan H.; Graves, Martin J.

2017-05-01

The paper reports a free-breathing black-blood CINE fast-spin echo (FSE) technique for measuring abdominal aortic wall motion. The free-breathing CINE FSE includes the following MR techniques: (1) variable-density sampling with fast iterative reconstruction; (2) inner-volume imaging; and (3) a blood-suppression preparation pulse. The proposed technique was evaluated in eight healthy subjects. The inner-volume imaging significantly reduced the intraluminal artifacts of respiratory motion (p  =  0.015). The quantitative measurements were a diameter of 16.3  ±  2.8 mm and wall distensibility of 2.0  ±  0.4 mm (12.5  ±  3.4%) and 0.7  ±  0.3 mm (4.1  ±  1.0%) for the anterior and posterior walls, respectively. The cyclic cross-sectional distensibility was 35  ±  15% greater in the systolic phase than in the diastolic phase. In conclusion, we developed a feasible CINE FSE method to measure the motion of the abdominal aortic wall, which will enable clinical scientists to study the elasticity of the abdominal aorta.

Single particle analysis based on Zernike phase contrast transmission electron microscopy.

Science.gov (United States)

Danev, Radostin; Nagayama, Kuniaki

2008-02-01

We present the first application of Zernike phase-contrast transmission electron microscopy to single-particle 3D reconstruction of a protein, using GroEL chaperonin as the test specimen. We evaluated the performance of the technique by comparing 3D models derived from Zernike phase contrast imaging, with models from conventional underfocus phase contrast imaging. The same resolution, about 12A, was achieved by both imaging methods. The reconstruction based on Zernike phase contrast data required about 30% fewer particles. The advantages and prospects of each technique are discussed.

Hard X-ray phase-contrast microscope for observing transparent specimens

Energy Technology Data Exchange (ETDEWEB)

Kagoshima, Y.; Yokoyama, Y.; Niimi, T.; Koyama, T.; Tsusaka, Y.; Matsui, J. [Himeji Institute of Technology, Graduate School of Science, Hyogo (Japan); Takai, K. [Japan synchrotron Radiation Research Institute, Mikazuki, Hyogo (Japan)

2002-08-01

A hard X-ray transmission imaging microscope has been in use at the beamline BL24XU of Spring-8. It makes use of a phase zone plate made of tantalum as its X-ray lens, and is capable of imaging the structure as fine as 125-nm line-and-space pattern. The Zernike's phase-contrast method has been implemented to the microscope with phase plates made of gold. The photon energy was tuned to 12 keV just above the L{sub 3} absorption edge of gold (11.9 keV) in order to increase the image contrast. Polystyrene micro particles as transparent specimens were imaged clearly in the opposite image contrast with phase plates to shift the phase of the central order spectra in the back focal plane of the objective by one-quarter and three-quarters of a period, while the absorption contrast image showed little image contrast. Performance of the newly developed phase zone plate has been tested and it was confirmed that the structure as fine as 60-mm line-and-space pattern was able to be imaged. (authors)

Grating-based X-ray phase contrast for biomedical imaging applications

International Nuclear Information System (INIS)

Pfeiffer, Franz; Willner, Marian; Chabior, Michael; Herzen, Julia; Helmholtz-Zentrum Geesthacht, Geesthacht; Auweter, Sigrid; Reiser, Maximilian; Bamberg, Fabian

2013-01-01

In this review article we describe the development of grating-based X-ray phase-contrast imaging, with particular emphasis on potential biomedical applications of the technology. We review the basics of image formation in grating-based phase-contrast and dark-field radiography and present some exemplary multimodal radiography results obtained with laboratory X-ray sources. Furthermore, we discuss the theoretical concepts to extend grating-based multimodal radiography to quantitative transmission, phase-contrast, and dark-field scattering computed tomography. (orig.)

In-line phase contrast micro-CT reconstruction for biomedical specimens.

Science.gov (United States)

Fu, Jian; Tan, Renbo

2014-01-01

X-ray phase contrast micro computed tomography (micro-CT) can non-destructively provide the internal structure information of soft tissues and low atomic number materials. It has become an invaluable analysis tool for biomedical specimens. Here an in-line phase contrast micro-CT reconstruction technique is reported, which consists of a projection extraction method and the conventional filter back-projection (FBP) reconstruction algorithm. The projection extraction is implemented by applying the Fourier transform to the forward projections of in-line phase contrast micro-CT. This work comprises a numerical study of the method and its experimental verification using a biomedical specimen dataset measured at an X-ray tube source micro-CT setup. The numerical and experimental results demonstrate that the presented technique can improve the imaging contrast of biomedical specimens. It will be of interest for a wide range of in-line phase contrast micro-CT applications in medicine and biology.

Left ventricular strain and its pattern estimated from cine CMR and validation with DENSE.

Science.gov (United States)

Gao, Hao; Allan, Andrew; McComb, Christie; Luo, Xiaoyu; Berry, Colin

2014-07-07

Measurement of local strain provides insight into the biomechanical significance of viable myocardium. We attempted to estimate myocardial strain from cine cardiovascular magnetic resonance (CMR) images by using a b-spline deformable image registration method. Three healthy volunteers and 41 patients with either recent or chronic myocardial infarction (MI) were studied at 1.5 Tesla with both cine and DENSE CMR. Regional circumferential and radial left ventricular strains were estimated from cine and DENSE acquisitions. In all healthy volunteers, there was no difference for peak circumferential strain (- 0.18 ± 0.04 versus - 0.18 ± 0.03, p = 0.76) between cine and DENSE CMR, however peak radial strain was overestimated from cine (0.84 ± 0.37 versus 0.49 ± 0.2, p cine were similar to the patterns from DENSE, including the strain evolution related to recovery time and strain patterns related to MI scar extent. Furthermore, cine-derived strain disclosed different strain patterns in MI and non-MI regions, and regions with transmural and non-transmural MI as DENSE. Although there were large variations with radial strain measurements from cine CMR images, useful circumferential strain information can be obtained from routine clinical CMR imaging. Cine strain analysis has potential to improve the diagnostic yield from routine CMR imaging in clinical practice.

The diagnostic value of cine-MR imaging in diseases of great vessels

International Nuclear Information System (INIS)

Sasaki, Shigeyuki; Yoshida, Hideaki; Matsui, Yoshiro; Sakuma, Makoto; Yasuda, Keihide; Tanabe, Tatsuzo; Chouji, H.

1990-01-01

The diagnostic value of cine magnetic resonance imaging (cine-MRI) was evaluated in 10 patients with diseases of great vessels. The parameters necessary to decide the appropriate treatment, such as presence and extension of intimal flap, DeBakey type classification, identification of the entry, differentiation between true and false lumen, and between thrombosis and slow flow were demonstrated in all patients with dissecting aortic aneurysm. However, abdominal aortic branches could not be demonstrated enough by cine-MRI, therefore conventional AOG was necessary to choose the operative procedure in these cases. In patients with thoracic aortic aneurysm (TAA), cine-MRI was valuable in demonstrating both blood flow and thrombus in the lumen of aneurysm, and AOG was thought to be unnecessary in most cases. Cine-MRI is a promising new technique for the evaluation of diseases of great vessels. (author)

Fully automated segmentation of left ventricle using dual dynamic programming in cardiac cine MR images

Science.gov (United States)

Jiang, Luan; Ling, Shan; Li, Qiang

2016-03-01

Cardiovascular diseases are becoming a leading cause of death all over the world. The cardiac function could be evaluated by global and regional parameters of left ventricle (LV) of the heart. The purpose of this study is to develop and evaluate a fully automated scheme for segmentation of LV in short axis cardiac cine MR images. Our fully automated method consists of three major steps, i.e., LV localization, LV segmentation at end-diastolic phase, and LV segmentation propagation to the other phases. First, the maximum intensity projection image along the time phases of the midventricular slice, located at the center of the image, was calculated to locate the region of interest of LV. Based on the mean intensity of the roughly segmented blood pool in the midventricular slice at each phase, end-diastolic (ED) and end-systolic (ES) phases were determined. Second, the endocardial and epicardial boundaries of LV of each slice at ED phase were synchronously delineated by use of a dual dynamic programming technique. The external costs of the endocardial and epicardial boundaries were defined with the gradient values obtained from the original and enhanced images, respectively. Finally, with the advantages of the continuity of the boundaries of LV across adjacent phases, we propagated the LV segmentation from the ED phase to the other phases by use of dual dynamic programming technique. The preliminary results on 9 clinical cardiac cine MR cases show that the proposed method can obtain accurate segmentation of LV based on subjective evaluation.

X-ray differential phase-contrast tomographic reconstruction with a phase line integral retrieval filter

International Nuclear Information System (INIS)

Fu, Jian; Hu, Xinhua; Li, Chen

2015-01-01

We report an alternative reconstruction technique for x-ray differential phase-contrast computed tomography (DPC-CT). This approach is based on a new phase line integral projection retrieval filter, which is rooted in the derivative property of the Fourier transform and counteracts the differential nature of the DPC-CT projections. It first retrieves the phase line integral from the DPC-CT projections. Then the standard filtered back-projection (FBP) algorithms popular in x-ray absorption-contrast CT are directly applied to the retrieved phase line integrals to reconstruct the DPC-CT images. Compared with the conventional DPC-CT reconstruction algorithms, the proposed method removes the Hilbert imaginary filter and allows for the direct use of absorption-contrast FBP algorithms. Consequently, FBP-oriented image processing techniques and reconstruction acceleration softwares that have already been successfully used in absorption-contrast CT can be directly adopted to improve the DPC-CT image quality and speed up the reconstruction

Evaluation of atrial, ventricular and atrioventricular septal defects by cine magnetic resonance imaging

International Nuclear Information System (INIS)

Akagi, Teiji; Kato, Hirohisa; Kiyomatsu, Yumi; Saiki, Kuninobu; Suzuki, Kazushige; Eto, Takaharu

1992-01-01

Cine magnetic resonance imaging (MRI) was performed on 20 patients (mean age: 5.3±4.4 years) with atrial, ventricular, or atrioventricular septal defects for evaluation of cardiac structure and blood flow. Prior to cine MRI, electrocardiographycally gated MRI using multislice scquisition was performed on all patients to localize optimal slice location. Cine-MRI was obtained with a 30 deg flip angle, 15 msec echo time, and 30 msec pulse repetition time, on a 256 x 256 or 128 x 128 acquisition matrix. Abnormalities of cardiac structure were well defined in all patients by gated cardiac imaging. In 18 of the 20 patients, cine-MRI was able to detect shunt flow, visualized as a low intensity signal in comparison with the surrounding blood flow. Cine-MRI can provide not only accurate anatomy of cardiac structures but functional assessment of the cardiac chamber, wall topology and flow relations. Cine-MRI will become an important noninvasive technique for assessment of anatomy and physiology in congenital heart disease. (author)

Direct comparison of high-temporal-resolution CINE MRI with Doppler ultrasound for assessment of diastolic dysfunction in mice.

Science.gov (United States)

Roberts, Thomas A; Price, Anthony N; Jackson, Laurence H; Taylor, Valerie; David, Anna L; Lythgoe, Mark F; Stuckey, Daniel J

2017-10-01

Diastolic dysfunction is a sensitive early indicator of heart failure and can provide additional data to conventional measures of systolic function. Transmitral Doppler ultrasound, which measures the one-dimensional flow of blood through the mitral valve, is currently the preferred method for the measurement of diastolic function, but the measurement of the left ventricular volume changes using high-temporal-resolution cinematic magnetic resonance imaging (CINE MRI) is an alternative approach which is emerging as a potentially more robust and user-independent technique. Here, we investigated the performance of high-temporal-resolution CINE MRI and compared it with ultrasound for the detection of diastolic dysfunction in a mouse model of myocardial infarction. An in-house, high-temporal-resolution, retrospectively gated CINE sequence was developed with a temporal resolution of 1 ms. Diastolic function in mice was assessed using a custom-made, open-source reconstruction package. Early (E) and late (A) left ventricular filling phases were easily identifiable, and these measurements were compared directly with high-frequency, pulsed-wave, Doppler ultrasound measurements of mitral valve inflow. A repeatability study established that high-temporal-resolution CINE MRI and Doppler ultrasound showed comparable accuracy when measuring E/A in normal control mice. However, when applied in a mouse model of myocardial infarction, high-temporal-resolution CINE MRI indicated diastolic heart failure (E/A = 0.94 ± 0.11), whereas ultrasound falsely detected normal cardiac function (E/A = 1.21 ± 0.11). The addition of high-temporal-resolution CINE MRI to preclinical imaging studies enhances the library of sequences available to cardiac researchers and potentially identifies diastolic heart failure early in disease progression. © 2017 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.

Two-dimensional sonographic cine imaging improves confidence in the initial evaluation of the fetal heart.

Science.gov (United States)

Poole, Patricia Sims; Chung, Romy; Lacoursiere, Yvette; Palmieri, Carolina Rossi; Hull, Andrew; Engelkemier, Dawn; Rochelle, Michele; Trivedi, Neha; Pretorius, Dolores H

2013-06-01

Initial screening sonography of the fetal heart with static images is often inadequate, resulting in repeated imaging or failure to detect abnormalities. We hypothesized that the addition of short cine clips would reduce the need for repeated imaging. Two-dimensional (2D) static sonograms and short 2D cine clips of the 4-chamber view and left and right ventricular outflow tracts were obtained from 342 patients with gestational ages of greater than 16 weeks. A diagnostic radiologist and a perinatologist retrospectively reviewed the static and cine images independently and graded them as normal, abnormal, or suboptimal. A statistically significant increase in the number of structures called normal was seen when 2D cine clips were added to static imaging for both observers (P cine images versus 61.9% with static images alone, whereas the perinatologist recorded 68.1% as normal versus 58.8%, respectively. The radiologist called 77.8% of structures normal with cine images only versus 61.9% with static images only (P cine images alone (38.9%) versus static images alone (58.8%). The use of cine loops alone resulted in no significant increase in the ability to clear the heart as normal. The maternal body mass index was inversely associated with the ability to clear structures when 2D cine images were added to static images (P cine clips to standard 2D static imaging of the fetal heart significantly improves the number of structures cleared as normal. Two-dimensional cine clips are easily obtained, add little time to a study, and require minimal archival space.

Control of an X-ray cine radiography apparatus

International Nuclear Information System (INIS)

Nishio, K.

1982-01-01

This patent application describes an X-ray cine radiography apparatus comprising an X-ray tube, an image intensifier for converting the X-rays transmitted through an object into a visual image and a cine camera for picking up the visual image, a photomultiplier detects the brightness of the visual image to produce a brightness signal and a potentiometer detects the actual tube voltage of said X-ray tube. (author)

Kinematic analysis of the knee joint by cine MRI

International Nuclear Information System (INIS)

Niitsu, Mamoru; Akisada, Masayoshi; Anno, Izumi; Matsumoto, Kunihiko; Kuno, Shin-ya; Miyakawa, Shunpei; Inouye, Tamon; Kose, Katsumi.

1989-01-01

In order to obtain the MR imaging of a moving knee joint, we developed a drive system of the knee. A reciprocating reversible motor with a rope and pulleys drove a knee brace with the knee bending and extending every two seconds. Using photo sensor probe for gating cine acquisition, we got 16-time frames/cycle MR images. Such as articular cartilage, ligaments and synovial fluid, the fine components of a moving knee joint were clearly seen. In a dynamic display, these cine images demonstrated 'actual' movement of the knee joint. Moving joint fluid and defect of anterior cruciate ligament were demonstrated in the case of knee injury. These findings were not seen on static images. Cine MR imaging was also helpful for evaluating the chronic joint disease and ligament reconstruction. Through the use of the present drive system and cine acquisition, dynamic MR imaging of a moving knee joint is clearly demonstrated and it may provide useful information in the kinematic analysis of the normal and pathologic knee. (author)

Escala propuesta para medir la calidad del servicio de los cines

Directory of Open Access Journals (Sweden)

Eduardo Torres Moraga1

2010-04-01

Full Text Available En la actualidad, existe un alto nivel de competencia entre las diferentes cadenas de cines que se encuentran en Chile. En este escenario, el éxito está determinado en gran parte por los servicios que estas ofrecen a sus clientes. Si bien previamente se han desarrollado escalas para medir la calidad del servicio percibida en diversos sectores, por sus características, es necesario construir una escala específica que pueda ser aplicada a los cines. Los resultados obtenidos por medio de este estudio muestran que la calidad del servicio de los cines percibida por los consumidores es un constructor multidimensional que difiere en gran parte de las escalas estándar propuestas anteriormente, y que además se compone de la confiabilidad, la atención personal, la accesibilidad, los tangibles del cine y los tangibles de la sala de proyección de la película. Estos resultados entregan a los directivos de marketing de los cines una importante herramienta que les permitirá medir y gestionar la calidad del servicio.

X-ray phase-contrast CT of a pancreatic ductal adenocarcinoma mouse model.

Directory of Open Access Journals (Sweden)

Arne Tapfer

Full Text Available To explore the potential of grating-based x-ray phase-contrast computed tomography (CT for preclinical research, a genetically engineered mouse model of pancreatic ductal adenocarcinoma (PDAC was investigated. One ex-vivo mouse specimen was scanned with different grating-based phase-contrast CT imaging setups covering two different settings: i high-resolution synchrotron radiation (SR imaging and ii dose-reduced imaging using either synchrotron radiation or a conventional x-ray tube source. These experimental settings were chosen to assess the potential of phase-contrast imaging for two different types of application: i high-performance imaging for virtual microscopy applications and ii biomedical imaging with increased soft-tissue contrast for in-vivo applications. For validation and as a reference, histological slicing and magnetic resonance imaging (MRI were performed on the same mouse specimen. For each x-ray imaging setup, attenuation and phase-contrast images were compared visually with regard to contrast in general, and specifically concerning the recognizability of lesions and cancerous tissue. To quantitatively assess contrast, the contrast-to-noise ratios (CNR of selected regions of interest (ROI in the attenuation images and the phase images were analyzed and compared. It was found that both for virtual microscopy and for in-vivo applications, there is great potential for phase-contrast imaging: in the SR-based benchmarking data, fine details about tissue composition are accessible in the phase images and the visibility of solid tumor tissue under dose-reduced conditions is markedly superior in the phase images. The present study hence demonstrates improved diagnostic value with phase-contrast CT in a mouse model of a complex endogenous cancer, promoting the use and further development of grating-based phase-contrast CT for biomedical imaging applications.

Phase contrast image segmentation using a Laue analyser crystal

International Nuclear Information System (INIS)

Kitchen, Marcus J; Paganin, David M; Lewis, Robert A; Pavlov, Konstantin M; Uesugi, Kentaro; Allison, Beth J; Hooper, Stuart B

2011-01-01

Dual-energy x-ray imaging is a powerful tool enabling two-component samples to be separated into their constituent objects from two-dimensional images. Phase contrast x-ray imaging can render the boundaries between media of differing refractive indices visible, despite them having similar attenuation properties; this is important for imaging biological soft tissues. We have used a Laue analyser crystal and a monochromatic x-ray source to combine the benefits of both techniques. The Laue analyser creates two distinct phase contrast images that can be simultaneously acquired on a high-resolution detector. These images can be combined to separate the effects of x-ray phase, absorption and scattering and, using the known complex refractive indices of the sample, to quantitatively segment its component materials. We have successfully validated this phase contrast image segmentation (PCIS) using a two-component phantom, containing an iodinated contrast agent, and have also separated the lungs and ribcage in images of a mouse thorax. Simultaneous image acquisition has enabled us to perform functional segmentation of the mouse thorax throughout the respiratory cycle during mechanical ventilation.

Preliminary study on X-ray phase contrast imaging using synchrotron radiation facility

International Nuclear Information System (INIS)

Xiong Zhuang; Wang Jianhua; Yu Yongqiang; Jiang Shiping; Chen Yang; Tian Yulian

2006-01-01

Objective: To study the methodology of X-ray phase contrast imaging using synchrotron radiation, and evaluate the quality of phase contrast images. Methods: Several experiments to obtain phase contrast images and absorption contrast images of various biological samples were conducted in Beijing Synchrotron Radiation Facility (BSRF), and then these images were interpreted to find out the difference between the two kinds of imaging methods. Results: Satisfactory phase contrast images of these various samples were obtained, and the quality of these images was superior to that obtained with absorption contrast imaging. The phase contrast formation is based on the phenomenon of fresnel diffraction which transforms phase shifts into intensity variations upon a simple act of free-space propagation, so it requires highly coherent X-rays and appropriate distance between sample and detector. This method of imaging is very useful in imaging of low-absorption objects or objects with little absorption variation, and its resolution is far higher than that of the conventional X-ray imaging. The photographs obtained showed very fine inner microstructure of the biological samples, and the smallest microstructure to be distinguished is within 30-40 μm. There is no doubt that phase contrast imaging has a practical applicability in medicine. Moreover, it improves greatly the efficiency and the resolution of the existing X-ray diagnostic techniques. Conclusions: X-ray phase contrast imaging can be performed with synchrotron radiation source and has some advantages over the conventional absorption contrast imaging. (authors)

High frame rate retrospectively triggered Cine MRI for assessment of murine diastolic function.

Science.gov (United States)

Coolen, Bram F; Abdurrachim, Desiree; Motaal, Abdallah G; Nicolay, Klaas; Prompers, Jeanine J; Strijkers, Gustav J

2013-03-01

To assess left ventricular (LV) diastolic function in mice with Cine MRI, a high frame rate (>60 frames per cardiac cycle) is required. For conventional electrocardiography-triggered Cine MRI, the frame rate is inversely proportional to the pulse repetition time (TR). However, TR cannot be lowered at will to increase the frame rate because of gradient hardware, spatial resolution, and signal-to-noise limitations. To overcome these limitations associated with electrocardiography-triggered Cine MRI, in this paper, we introduce a retrospectively triggered Cine MRI protocol capable of producing high-resolution high frame rate Cine MRI of the mouse heart for addressing left ventricular diastolic function. Simulations were performed to investigate the influence of MRI sequence parameters and the k-space filling trajectory in relation to the desired number of frames per cardiac cycle. An optimized protocol was applied in vivo and compared with electrocardiography-triggered Cine for which a high-frame rate could only be achieved by several interleaved acquisitions. Retrospective high frame rate Cine MRI proved superior to the interleaved electrocardiography-triggered protocols. High spatial-resolution Cine movies with frames rates up to 80 frames per cardiac cycle were obtained in 25 min. Analysis of left ventricular filling rate curves allowed accurate determination of early and late filling rates and revealed subtle impairments in left ventricular diastolic function of diabetic mice in comparison with nondiabetic mice. Copyright © 2012 Wiley Periodicals, Inc.

Left ventricular strain and its pattern estimated from cine CMR and validation with DENSE

International Nuclear Information System (INIS)

Gao, Hao; Luo, Xiaoyu; Allan, Andrew; McComb, Christie; Berry, Colin

2014-01-01

Measurement of local strain provides insight into the biomechanical significance of viable myocardium. We attempted to estimate myocardial strain from cine cardiovascular magnetic resonance (CMR) images by using a b-spline deformable image registration method. Three healthy volunteers and 41 patients with either recent or chronic myocardial infarction (MI) were studied at 1.5 Tesla with both cine and DENSE CMR. Regional circumferential and radial left ventricular strains were estimated from cine and DENSE acquisitions. In all healthy volunteers, there was no difference for peak circumferential strain (− 0.18 ± 0.04 versus − 0.18 ± 0.03, p = 0.76) between cine and DENSE CMR, however peak radial strain was overestimated from cine (0.84 ± 0.37 versus 0.49 ± 0.2, p < 0.01). In the patient study, the peak strain patterns predicted by cine were similar to the patterns from DENSE, including the strain evolution related to recovery time and strain patterns related to MI scar extent. Furthermore, cine-derived strain disclosed different strain patterns in MI and non-MI regions, and regions with transmural and non-transmural MI as DENSE. Although there were large variations with radial strain measurements from cine CMR images, useful circumferential strain information can be obtained from routine clinical CMR imaging. Cine strain analysis has potential to improve the diagnostic yield from routine CMR imaging in clinical practice. (paper)

Rapid reformatting of cine CT data

International Nuclear Information System (INIS)

Wyatt, E.D.; Reynolds, R.A.

1989-01-01

Cine CT scanners acquire data sufficiently rapidly to freeze the cardiac motion. Display hardware with sufficient highspeed computer memory permits instantaneous reformatting of sections at any orientation. Normal or abnormal cardiac motion may be studies interactively along any axial, sagittal, coronal, or oblique plane through the beating heart. Cine Ct studies, consisting of eight levels through the heart with 8-mm interlevel spacing, acquired at 10 time intervals for a total of 80 sections, were acquired on an Imatron C-100 scanner and displayed. Each entire study was loaded into t = internal display processor memory, permitting instantaneous recall without loss of spatial or density resolution. Results are presented

Automatic segmentation and disease classification using cardiac cine MR images

NARCIS (Netherlands)

Wolterink, Jelmer M.; Leiner, Tim; Viergever, Max A.; Išgum, Ivana

2018-01-01

Segmentation of the heart in cardiac cine MR is clinically used to quantify cardiac function. We propose a fully automatic method for segmentation and disease classification using cardiac cine MR images. A convolutional neural network (CNN) was designed to simultaneously segment the left ventricle

Cine interactivo como estrategia de intervención grupal

Directory of Open Access Journals (Sweden)

Paola Lauretti

2009-05-01

Full Text Available Utilizando el concepto de cine interactivo como agente motor de la relación inter e intra personal, presentamosuna experiencia con un grupo de adultos, con la finalidad de establecer el valor del cine como un recurso útil para laintervención grupal. El método de trabajo descriptivo se desarrolló en varias etapas: 1 aplicación del CuestionarioExploración de Necesidades (CEN del cual se extrajeron los principales temas a tratar; 2 selección, por parte delequipo de investigación, de aquellas películas que mejor se adaptaban a las necesidades detectadas; 3 aplicación delCuestionario Actitud frente al Cine (CAC para sus analizar su actitud antes de iniciar la experiencia; 4 proyecciónde las películas seleccionadas; 5 re aplicación del CAC dos meses después de culminado el proceso, para analizar loscambios operados con relación al cine. Los temas trabajados fueron relación de pareja y relaciones padres-hijos bajola utilización del modelo CAPAS el cual promueve el análisis de las situaciones planteadas en los siguientes pasos: C:comentario general del contenido; A: análisis del problema central; P: proceso de internalización; A: auto reflexión y S:Solución del conflicto. Los resultados apuntan hacia la importancia de considerar el cine como una estrategia valiosaen la intervención en grupos.

Cine vasco y euskera: debates de identidad

OpenAIRE

Fernández, Joxean

2013-01-01

INTRODUCCIÓN: LA ÓSMOSIS HISTORIA-CINE Los físicos suelen hablar de ósmosis para referirse al paso recíproco de dos líquidos de distinta densidad a través de una membrana semipermeable que los separa. Asimismo, en lenguaje literario, hablamos de ósmosis para definir simplemente influencias recíprocas. Nos permitimos utilizar aquí este término prestado de otras disciplinas científicas para tratar de obtener una imagen de las relaciones que el cine y la historia vienen manteniendo desde que aqu...

Practical aspects of Boersch phase contrast electron microscopy of biological specimens

Energy Technology Data Exchange (ETDEWEB)

Walter, Andreas [Max-Planck-Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60439 Frankfurt (Germany); Muzik, Heiko; Vieker, Henning; Turchanin, Andrey; Beyer, Andre; Goelzhaeuser, Armin [University of Bielefeld, Physics of Supramolecular Systems and Surfaces, Universitaetsstr. 25, D-33615 Bielefeld (Germany); Lacher, Manfred; Steltenkamp, Siegfried; Schmitz, Sam; Holik, Peter [Caesar Research Center, Ludwig-Erhard-Allee 2, D-53175 Bonn (Germany); Kuehlbrandt, Werner [Max-Planck-Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60439 Frankfurt (Germany); Rhinow, Daniel, E-mail: daniel.rhinow@biophys.mpg.de [Max-Planck-Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60439 Frankfurt (Germany)

2012-05-15

Implementation of physical phase plates into transmission electron microscopes to achieve in-focus contrast for ice-embedded biological specimens poses several technological challenges. During the last decade several phase plates designs have been introduced and tested for electron cryo-microscopy (cryoEM), including thin film (Zernike) phase plates and electrostatic devices. Boersch phase plates (BPPs) are electrostatic einzel lenses shifting the phase of the unscattered beam by an arbitrary angle. Adjusting the phase shift to 90 Degree-Sign achieves the maximum contrast transfer for phase objects such as biomolecules. Recently, we reported the implementation of a BPP into a dedicated phase contrast aberration-corrected electron microscope (PACEM) and demonstrated its use to generate in-focus contrast of frozen-hydrated specimens. However, a number of obstacles need to be overcome before BPPs can be used routinely, mostly related to the phase plate devices themselves. CryoEM with a physical phase plate is affected by electrostatic charging, obliteration of low spatial frequencies, and mechanical drift. Furthermore, BPPs introduce single sideband contrast (SSB), due to the obstruction of Friedel mates in the diffraction pattern. In this study we address the technical obstacles in detail and show how they may be overcome. We use X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) to identify contaminants responsible for electrostatic charging, which occurs with most phase plates. We demonstrate that obstruction of low-resolution features is significantly reduced by lowering the acceleration voltage of the microscope. Finally, we present computational approaches to correct BPP images for SSB contrast and to compensate for mechanical drift of the BPP. -- Highlights: Black-Right-Pointing-Pointer Various obstacles need to be overcome before Boersch phase plates can be used routinely. Black-Right-Pointing-Pointer Technical problems include

Practical aspects of Boersch phase contrast electron microscopy of biological specimens

International Nuclear Information System (INIS)

Walter, Andreas; Muzik, Heiko; Vieker, Henning; Turchanin, Andrey; Beyer, André; Gölzhäuser, Armin; Lacher, Manfred; Steltenkamp, Siegfried; Schmitz, Sam; Holik, Peter; Kühlbrandt, Werner; Rhinow, Daniel

2012-01-01

Implementation of physical phase plates into transmission electron microscopes to achieve in-focus contrast for ice-embedded biological specimens poses several technological challenges. During the last decade several phase plates designs have been introduced and tested for electron cryo-microscopy (cryoEM), including thin film (Zernike) phase plates and electrostatic devices. Boersch phase plates (BPPs) are electrostatic einzel lenses shifting the phase of the unscattered beam by an arbitrary angle. Adjusting the phase shift to 90° achieves the maximum contrast transfer for phase objects such as biomolecules. Recently, we reported the implementation of a BPP into a dedicated phase contrast aberration-corrected electron microscope (PACEM) and demonstrated its use to generate in-focus contrast of frozen–hydrated specimens. However, a number of obstacles need to be overcome before BPPs can be used routinely, mostly related to the phase plate devices themselves. CryoEM with a physical phase plate is affected by electrostatic charging, obliteration of low spatial frequencies, and mechanical drift. Furthermore, BPPs introduce single sideband contrast (SSB), due to the obstruction of Friedel mates in the diffraction pattern. In this study we address the technical obstacles in detail and show how they may be overcome. We use X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) to identify contaminants responsible for electrostatic charging, which occurs with most phase plates. We demonstrate that obstruction of low-resolution features is significantly reduced by lowering the acceleration voltage of the microscope. Finally, we present computational approaches to correct BPP images for SSB contrast and to compensate for mechanical drift of the BPP. -- Highlights: ► Various obstacles need to be overcome before Boersch phase plates can be used routinely. ► Technical problems include electrostatic charging, mechanical drift, and image artefacts. �

Intramyocardial strain estimation from cardiac cine MRI.

Science.gov (United States)

Elnakib, Ahmed; Beache, Garth M; Gimel'farb, Georgy; El-Baz, Ayman

2015-08-01

Functional strain is one of the important clinical indicators for the quantification of heart performance and the early detection of cardiovascular diseases, and functional strain parameters are used to aid therapeutic decisions and follow-up evaluations after cardiac surgery. A comprehensive framework for deriving functional strain parameters at the endocardium, epicardium, and mid-wall of the left ventricle (LV) from conventional cine MRI data was developed and tested. Cine data were collected using short TR-/TE-balanced steady-state free precession acquisitions on a 1.5T Siemens Espree scanner. The LV wall borders are segmented using a level set-based deformable model guided by a stochastic force derived from a second-order Markov-Gibbs random field model that accounts for the object shape and appearance features. Then, the mid-wall of the segmented LV is determined based on estimating the centerline between the endocardium and epicardium of the LV. Finally, a geometrical Laplace-based method is proposed to track corresponding points on successive myocardial contours throughout the cardiac cycle in order to characterize the strain evolutions. The method was tested using simulated phantom images with predefined point locations of the LV wall throughout the cardiac cycle. The method was tested on 30 in vivo datasets to evaluate the feasibility of the proposed framework to index functional strain parameters. The cine MRI-based model agreed with the ground truth for functional metrics to within 0.30 % for indexing the peak systolic strain change and 0.29 % (per unit time) for indexing systolic and diastolic strain rates. The method was feasible for in vivo extraction of functional strain parameters. Strain indexes of the endocardium, mid-wall, and epicardium can be derived from routine cine images using automated techniques, thereby improving the utility of cine MRI data for characterization of myocardial function. Unlike traditional texture-based tracking, the

Evaluation of potential internal target volume of liver tumors using cine-MRI.

Science.gov (United States)

Akino, Yuichi; Oh, Ryoong-Jin; Masai, Norihisa; Shiomi, Hiroya; Inoue, Toshihiko

2014-11-01

Four-dimensional computed tomography (4DCT) is widely used for evaluating moving tumors, including lung and liver cancers. For patients with unstable respiration, however, the 4DCT may not visualize tumor motion properly. High-speed magnetic resonance imaging (MRI) sequences (cine-MRI) permit direct visualization of respiratory motion of liver tumors without considering radiation dose exposure to patients. Here, the authors demonstrated a technique for evaluating internal target volume (ITV) with consideration of respiratory variation using cine-MRI. The authors retrospectively evaluated six patients who received stereotactic body radiotherapy (SBRT) to hepatocellular carcinoma. Before acquiring planning CT, sagittal and coronal cine-MRI images were acquired for 30 s with a frame rate of 2 frames/s. The patient immobilization was conducted under the same condition as SBRT. Planning CT images were then acquired within 15 min from cine-MRI image acquisitions, followed by a 4DCT scan. To calculate tumor motion, the motion vectors between two continuous frames of cine-MRI images were calculated for each frame using the pyramidal Lucas-Kanade method. The target contour was delineated on one frame, and each vertex of the contour was shifted and copied onto the following frame using neighboring motion vectors. 3D trajectory data were generated with the centroid of the contours on sagittal and coronal images. To evaluate the accuracy of the tracking method, the motion of clearly visible blood vessel was analyzed with the motion tracking and manual detection techniques. The target volume delineated on the 50% (end-exhale) phase of 4DCT was translated with the trajectory data, and the distribution of the occupancy probability of target volume was calculated as potential ITV (ITV Potential). The concordance between ITV Potential and ITV estimated with 4DCT (ITV 4DCT) was evaluated using the Dice's similarity coefficient (DSC). The distance between blood vessel positions

MR imaging of carotid webs

International Nuclear Information System (INIS)

Boesen, Mari E.; Eswaradass, Prasanna Venkatesan; Singh, Dilip; Mitha, Alim P.; Menon, Bijoy K.; Goyal, Mayank; Frayne, Richard

2017-01-01

We propose a magnetic resonance (MR) imaging protocol for the characterization of carotid web morphology, composition, and vessel wall dynamics. The purpose of this case series was to determine the feasibility of imaging carotid webs with MR imaging. Five patients diagnosed with carotid web on CT angiography were recruited to undergo a 30-min MR imaging session. MR angiography (MRA) images of the carotid artery bifurcation were acquired. Multi-contrast fast spin echo (FSE) images were acquired axially about the level of the carotid web. Two types of cardiac phase resolved sequences (cineFSE and cine phase contrast) were acquired to visualize the elasticity of the vessel wall affected by the web. Carotid webs were identified on MRA in 5/5 (100%) patients. Multi-contrast FSE revealed vessel wall thickening and cineFSE demonstrated regional changes in distensibility surrounding the webs in these patients. Our MR imaging protocol enables an in-depth evaluation of patients with carotid webs: morphology (by MRA), composition (by multi-contrast FSE), and wall dynamics (by cineFSE). (orig.)

MR imaging of carotid webs

Energy Technology Data Exchange (ETDEWEB)

Boesen, Mari E. [University of Calgary, Department of Biomedical Engineering, Calgary (Canada); Foothills Medical Centre, Seaman Family MR Research Centre, Calgary (Canada); Eswaradass, Prasanna Venkatesan; Singh, Dilip; Mitha, Alim P.; Menon, Bijoy K. [University of Calgary, Department of Clinical Neurosciences, Calgary (Canada); Foothills Medical Centre, Calgary Stroke Program, Calgary (Canada); Goyal, Mayank [Foothills Medical Centre, Calgary Stroke Program, Calgary (Canada); University of Calgary, Department of Radiology, Calgary (Canada); Frayne, Richard [Foothills Medical Centre, Seaman Family MR Research Centre, Calgary (Canada); University of Calgary, Hotchkiss Brain Institute, Calgary (Canada)

2017-04-15

We propose a magnetic resonance (MR) imaging protocol for the characterization of carotid web morphology, composition, and vessel wall dynamics. The purpose of this case series was to determine the feasibility of imaging carotid webs with MR imaging. Five patients diagnosed with carotid web on CT angiography were recruited to undergo a 30-min MR imaging session. MR angiography (MRA) images of the carotid artery bifurcation were acquired. Multi-contrast fast spin echo (FSE) images were acquired axially about the level of the carotid web. Two types of cardiac phase resolved sequences (cineFSE and cine phase contrast) were acquired to visualize the elasticity of the vessel wall affected by the web. Carotid webs were identified on MRA in 5/5 (100%) patients. Multi-contrast FSE revealed vessel wall thickening and cineFSE demonstrated regional changes in distensibility surrounding the webs in these patients. Our MR imaging protocol enables an in-depth evaluation of patients with carotid webs: morphology (by MRA), composition (by multi-contrast FSE), and wall dynamics (by cineFSE). (orig.)

Robustness of phase retrieval methods in x-ray phase contrast imaging: A comparison

International Nuclear Information System (INIS)

Yan, Aimin; Wu, Xizeng; Liu, Hong

2011-01-01

Purpose: The robustness of the phase retrieval methods is of critical importance for limiting and reducing radiation doses involved in x-ray phase contrast imaging. This work is to compare the robustness of two phase retrieval methods by analyzing the phase maps retrieved from the experimental images of a phantom. Methods: Two phase retrieval methods were compared. One method is based on the transport of intensity equation (TIE) for phase contrast projections, and the TIE-based method is the most commonly used method for phase retrieval in the literature. The other is the recently developed attenuation-partition based (AP-based) phase retrieval method. The authors applied these two methods to experimental projection images of an air-bubble wrap phantom for retrieving the phase map of the bubble wrap. The retrieved phase maps obtained by using the two methods are compared. Results: In the wrap's phase map retrieved by using the TIE-based method, no bubble is recognizable, hence, this method failed completely for phase retrieval from these bubble wrap images. Even with the help of the Tikhonov regularization, the bubbles are still hardly visible and buried in the cluttered background in the retrieved phase map. The retrieved phase values with this method are grossly erroneous. In contrast, in the wrap's phase map retrieved by using the AP-based method, the bubbles are clearly recovered. The retrieved phase values with the AP-based method are reasonably close to the estimate based on the thickness-based measurement. The authors traced these stark performance differences of the two methods to their different techniques employed to deal with the singularity problem involved in the phase retrievals. Conclusions: This comparison shows that the conventional TIE-based phase retrieval method, regardless if Tikhonov regularization is used or not, is unstable against the noise in the wrap's projection images, while the AP-based phase retrieval method is shown in these

An integrated model-driven method for in-treatment upper airway motion tracking using cine MRI in head and neck radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Li, Hua, E-mail: huli@radonc.wustl.edu; Chen, Hsin-Chen; Dolly, Steven; Li, Harold; Fischer-Valuck, Benjamin; Mazur, Thomas; Gach, Michael; Kashani, Rojano; Green, Olga; Rodriguez, Vivian; Gay, Hiram; Thorstad, Wade; Mutic, Sasa [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Victoria, James; Dempsey, James [ViewRay Incorporated, Inc., Oakwood Village, Ohio 44146 (United States); Ruan, Su [Laboratoire LITIS (EA 4108), Equipe Quantif, University of Rouen, Rouen 76183 (France); Anastasio, Mark [Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63110 (United States)

2016-08-15

Purpose: For the first time, MRI-guided radiation therapy systems can acquire cine images to dynamically monitor in-treatment internal organ motion. However, the complex head and neck (H&N) structures and low-contrast/resolution of on-board cine MRI images make automatic motion tracking a very challenging task. In this study, the authors proposed an integrated model-driven method to automatically track the in-treatment motion of the H&N upper airway, a complex and highly deformable region wherein internal motion often occurs in an either voluntary or involuntary manner, from cine MRI images for the analysis of H&N motion patterns. Methods: Considering the complex H&N structures and ensuring automatic and robust upper airway motion tracking, the authors firstly built a set of linked statistical shapes (including face, face-jaw, and face-jaw-palate) using principal component analysis from clinically approved contours delineated on a set of training data. The linked statistical shapes integrate explicit landmarks and implicit shape representation. Then, a hierarchical model-fitting algorithm was developed to align the linked shapes on the first image frame of a to-be-tracked cine sequence and to localize the upper airway region. Finally, a multifeature level set contour propagation scheme was performed to identify the upper airway shape change, frame-by-frame, on the entire image sequence. The multifeature fitting energy, including the information of intensity variations, edge saliency, curve geometry, and temporal shape continuity, was minimized to capture the details of moving airway boundaries. Sagittal cine MR image sequences acquired from three H&N cancer patients were utilized to demonstrate the performance of the proposed motion tracking method. Results: The tracking accuracy was validated by comparing the results to the average of two manual delineations in 50 randomly selected cine image frames from each patient. The resulting average dice similarity

An integrated model-driven method for in-treatment upper airway motion tracking using cine MRI in head and neck radiation therapy

International Nuclear Information System (INIS)

Li, Hua; Chen, Hsin-Chen; Dolly, Steven; Li, Harold; Fischer-Valuck, Benjamin; Mazur, Thomas; Gach, Michael; Kashani, Rojano; Green, Olga; Rodriguez, Vivian; Gay, Hiram; Thorstad, Wade; Mutic, Sasa; Victoria, James; Dempsey, James; Ruan, Su; Anastasio, Mark

2016-01-01

Purpose: For the first time, MRI-guided radiation therapy systems can acquire cine images to dynamically monitor in-treatment internal organ motion. However, the complex head and neck (H&N) structures and low-contrast/resolution of on-board cine MRI images make automatic motion tracking a very challenging task. In this study, the authors proposed an integrated model-driven method to automatically track the in-treatment motion of the H&N upper airway, a complex and highly deformable region wherein internal motion often occurs in an either voluntary or involuntary manner, from cine MRI images for the analysis of H&N motion patterns. Methods: Considering the complex H&N structures and ensuring automatic and robust upper airway motion tracking, the authors firstly built a set of linked statistical shapes (including face, face-jaw, and face-jaw-palate) using principal component analysis from clinically approved contours delineated on a set of training data. The linked statistical shapes integrate explicit landmarks and implicit shape representation. Then, a hierarchical model-fitting algorithm was developed to align the linked shapes on the first image frame of a to-be-tracked cine sequence and to localize the upper airway region. Finally, a multifeature level set contour propagation scheme was performed to identify the upper airway shape change, frame-by-frame, on the entire image sequence. The multifeature fitting energy, including the information of intensity variations, edge saliency, curve geometry, and temporal shape continuity, was minimized to capture the details of moving airway boundaries. Sagittal cine MR image sequences acquired from three H&N cancer patients were utilized to demonstrate the performance of the proposed motion tracking method. Results: The tracking accuracy was validated by comparing the results to the average of two manual delineations in 50 randomly selected cine image frames from each patient. The resulting average dice similarity

Quantitative phase imaging and differential interference contrast imaging for biological TEM

International Nuclear Information System (INIS)

Allman, B.E.; McMahon, P.J.; Barone-Nugent, E.D.; Nugent, E.D.

2002-01-01

Full text: Phase microscopy is a central technique in science. An experienced microscopist uses this effect to visualise (edge) structure within transparent samples by slightly defocusing the microscope. Although widespread in optical microscopy, phase contrast transmission electron microscopy (TEM) has not been widely adopted. TEM for biological specimens has largely relied on staining techniques to yield sufficient contrast. We show here a simple method for quantitative TEM phase microscopy that quantifies this phase contrast effect. Starting with conventional, digital, bright field images of the sample, our algorithm provides quantitative phase information independent of the sample's bright field intensity image. We present TEM phase images of a range of stained and unstained, biological and material science specimens. This independent phase and intensity information is then used to emulate a range of phase visualisation images familiar to optical microscopy, e.g. differential interference contrast. The phase images contain features not visible with the other imaging modalities. Further, if the TEM samples have been prepared on a microtome to a uniform thickness, the phase information can be converted into refractive index structure of the specimen. Copyright (2002) Australian Society for Electron Microscopy Inc

Cine MR imaging of cerebrospinal fluid flow

International Nuclear Information System (INIS)

Kawahara, K.; Yoshikawa, A.; Maeda, M.; Hamachi, J.; Morita, R.; Mishima, T.; Yamada, R.

1988-01-01

Cine MR imaging was used to study cerebrospinal fluid (CSF) flow in five patients with various kinds of hydrocephalus, 14 patients with brain atrophy, and 26 healthy subjects. For each study, sagittal and axial sections were obtained. In this study, the authors detected cerebrospinal fluid flow, apparent as high signal intensity, and its direction. They detected the outflow from the foramen of Monro, aqueduct, and foramen of Magendie in sagittal cine images of patients with those with normal-pressure hydrocehalus (NPH), those with brain atrophy, and controls. Especially in patients with NPH, the markedly high signal intensity from CSF flow was observeed in the third and fourth ventricles. In patients with obstructive hydrocephalus, the fourth ventricle tumor, the outflow of CSF was not present. In axial sections, the signal intensity of aqueduct in patients with obstructive hydrocephalus was lower, whereas that in patients with NPH, controls, and those with atrophy was higher than in the midbrain. Cine MR imaging is a very attractive technique in diagnosing hydrocephalus and other abnormal conditions

Cine CT in the evaluation of coronary bypass graft patency

International Nuclear Information System (INIS)

Stanford, W.; Rooholamini, M.; Rumberger, J.; Marcus, M.; Hiratzka, L.

1986-01-01

Cine CT produces axial images over an 8-cm section of the aorta in 50 msec. This characteristic makes the technique useful for evaluating coronary bypass graft (CBG) patency. With the use of 40 ml of 67% iothalamate sodium injected via an antecubital vein, 28 patients with 68 CBGs underwent cine CT. Ten patients with 21 CBGs also underwent cardiac catheterization. In the latter group the overall accuracy of cine CT compared to cardiac catheterization was 95.2% (20/21). The sensitivity was 94.1% (16/17), and the specificity was 100% (4/4). This figure compares favorably with the 92% sensitivity achieved with conventional CT

Enhanced phase contrast transfer using ptychography combined with a pre-specimen phase plate in a scanning transmission electron microscope

Energy Technology Data Exchange (ETDEWEB)

Yang, Hao; Ercius, Peter [Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Nellist, Peter D. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Ophus, Colin, E-mail: clophus@lbl.gov [Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

2016-12-15

The ability to image light elements in both crystalline and noncrystalline materials at near atomic resolution with an enhanced contrast is highly advantageous to understand the structure and properties of a wide range of beam sensitive materials including biological specimens and molecular hetero-structures. This requires the imaging system to have an efficient phase contrast transfer at both low and high spatial frequencies. In this work we introduce a new phase contrast imaging method in a scanning transmission electron microscope (STEM) using a pre-specimen phase plate in the probe forming aperture, combined with a fast pixelated detector to record diffraction patterns at every probe position, and phase reconstruction using ptychography. The phase plate significantly enhances the contrast transfer of low spatial frequency information, and ptychography maximizes the extraction of the phase information at all spatial frequencies. In addition, the STEM probe with the presence of the phase plate retains its atomic resolution, allowing simultaneous incoherent Z-contrast imaging to be obtained along with the ptychographic phase image. An experimental image of Au nanoparticles on a carbon support shows high contrast for both materials. Multislice image simulations of a DNA molecule shows the capability of imaging soft matter at low dose conditions, which implies potential applications of low dose imaging of a wide range of beam sensitive materials. - Highlights: • This work demonstrates a phase contrast imaging method by combining a pre-specimen phase plate with ptychogrpahy. • This method is shown to have a high phase contrast transfer efficiency at both low and high spatial frequencies. • Unlike CTEM which uses a heavy defocus to gain contrast, the phase plate gives a linear phase contrast at zero defocus aberrations. • Image simulations of DNA suggest this method is highly attractive for imaging beam sensitive materials at a low dose.

Cine-CT: A new technique in X-ray computed tomography

International Nuclear Information System (INIS)

Jaschke, W.; Georgi, M.; Lipton, M.J.; Gould, R.G.

1988-01-01

The 'Cine-CT' belongs to a new generation of CT devices permitting not only diagnostics on a morphological basis but also function studies. By means of Cine-CT's electron beam technique, image frequencies of up to 17 images per second and exposure times of 50 msec are possible. (orig.) [de

Grating-based x-ray differential phase contrast imaging with twin peaks in phase-stepping curves—phase retrieval and dewrapping

Energy Technology Data Exchange (ETDEWEB)

Yang, Yi; Xie, Huiqiao; Tang, Xiangyang, E-mail: xiangyang.tang@emory.edu [Imaging and Medical Physics, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1701 Uppergate Dr., C-5018, Atlanta, Georgia 30322 (United States); Cai, Weixing [Department of Radiation Oncology, Brigham and Women’s Hospital Harvard Medical School, 75 Francis Street, Boston, Massachusetts 02115 (United States); Mao, Hui [Laboratory of Functional and Molecular Imaging and Nanomedicine, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1841 Clifton Road NE, Atlanta, Georgia 30329 (United States)

2016-06-15

Purpose: X-ray differential phase contrast CT implemented with Talbot interferometry employs phase-stepping to extract information of x-ray attenuation, phase shift, and small-angle scattering. Since inaccuracy may exist in the absorption grating G{sub 2} due to an imperfect fabrication, the effective period of G{sub 2} can be as large as twice the nominal period, leading to a phenomenon of twin peaks that differ remarkably in their heights. In this work, the authors investigate how to retrieve and dewrap the phase signal from the phase-stepping curve (PSC) with the feature of twin peaks for x-ray phase contrast imaging. Methods: Based on the paraxial Fresnel–Kirchhoff theory, the analytical formulae to characterize the phenomenon of twin peaks in the PSC are derived. Then an approach to dewrap the retrieved phase signal by jointly using the phases of the first- and second-order Fourier components is proposed. Through an experimental investigation using a prototype x-ray phase contrast imaging system implemented with Talbot interferometry, the authors evaluate and verify the derived analytic formulae and the proposed approach for phase retrieval and dewrapping. Results: According to theoretical analysis, the twin-peak phenomenon in PSC is a consequence of combined effects, including the inaccuracy in absorption grating G{sub 2}, mismatch between phase grating and x-ray source spectrum, and finite size of x-ray tube’s focal spot. The proposed approach is experimentally evaluated by scanning a phantom consisting of organic materials and a lab mouse. The preliminary data show that compared to scanning G{sub 2} over only one single nominal period and correcting the measured phase signal with an intuitive phase dewrapping method that is being used in the field, stepping G{sub 2} over twice its nominal period and dewrapping the measured phase signal with the proposed approach can significantly improve the quality of x-ray differential phase contrast imaging in both

Analysis of blowout fractures using cine mode MRI

International Nuclear Information System (INIS)

Kawahara, Masaaki; Shiihara, Kumiko; Kimura, Hisashi; Fukai, Sakuko; Tabuchi, Akio; Kojo, Tuyoshi

1995-01-01

By observing conventional CT and MRI images, it is difficult to distinguish extension failure from adhesion, bone fracture or damage to the extraocular muscle, any one of which may be the direct cause of the eye movement disturbance accompanying blowout fracture. We therefore carried out dynamic analysis of eye movement disturbance using a cine mode MRI. We put seven fixation points in the gantry of the MRI and filmed eye movement disturbances by the gradient echo method, using a surface coil and holding the vision on each fixation point. We also video recorded the CRT monitor of the MRI to obtain dynamic MRI images. The subjects comprised 5 cases (7-23 years old). In 4 cases, we started orthoptic treatment, saccadic eye movement training, convergence training and fusional amplitude training after surgery, with only orthoptic treatment in the 5 th case. In all cases, fusion area improvement was recognized during training. In 2 cases examined by cine mode MRI before and after surgery, we observed improved eye movement after training, the effectiveness of which was thereby proven. Also, using cine mode MRI we were able to determine the character of incarcerated tissue and the cause of eye movement disturbance. We conclude that it blowout fracture, cine mode MRI may be useful in selecting treatment and observing its effectiveness. (author)

La imposible modernidad: desarrollo y pautas de persistencia en los estereotipos masculinos andaluces en el cine franquista

Directory of Open Access Journals (Sweden)

Inmaculada Sánchez-Alarcón

2012-01-01

Full Text Available Este trabajo define los modelos de masculinidad relacionados con Andalucía en las películas españolas del franquismo y su continuidad. En contraste con la exaltación de valores viriles dominante en el cine de la época,estos personajes masculinos se definen por su vulnerabilidad y se convierten en símbolo persistente de tradición.

Origins of phase contrast in the atomic force microscope in liquids.

Science.gov (United States)

Melcher, John; Carrasco, Carolina; Xu, Xin; Carrascosa, José L; Gómez-Herrero, Julio; José de Pablo, Pedro; Raman, Arvind

2009-08-18

We study the physical origins of phase contrast in dynamic atomic force microscopy (dAFM) in liquids where low-stiffness microcantilever probes are often used for nanoscale imaging of soft biological samples with gentle forces. Under these conditions, we show that the phase contrast derives primarily from a unique energy flow channel that opens up in liquids due to the momentary excitation of higher eigenmodes. Contrary to the common assumption, phase-contrast images in liquids using soft microcantilevers are often maps of short-range conservative interactions, such as local elastic response, rather than tip-sample dissipation. The theory is used to demonstrate variations in local elasticity of purple membrane and bacteriophage 29 virions in buffer solutions using the phase-contrast images.

In-Line Phase-Contrast X-ray Imaging and Tomography for Materials Science.

Science.gov (United States)

Mayo, Sheridan C; Stevenson, Andrew W; Wilkins, Stephen W

2012-05-24

X-ray phase-contrast imaging and tomography make use of the refraction of X-rays by the sample in image formation. This provides considerable additional information in the image compared to conventional X-ray imaging methods, which rely solely on X-ray absorption by the sample. Phase-contrast imaging highlights edges and internal boundaries of a sample and is thus complementary to absorption contrast, which is more sensitive to the bulk of the sample. Phase-contrast can also be used to image low-density materials, which do not absorb X-rays sufficiently to form a conventional X-ray image. In the context of materials science, X-ray phase-contrast imaging and tomography have particular value in the 2D and 3D characterization of low-density materials, the detection of cracks and voids and the analysis of composites and multiphase materials where the different components have similar X-ray attenuation coefficients. Here we review the use of phase-contrast imaging and tomography for a wide variety of materials science characterization problems using both synchrotron and laboratory sources and further demonstrate the particular benefits of phase contrast in the laboratory setting with a series of case studies.

Quantitative breast tissue characterization using grating-based x-ray phase-contrast imaging

Science.gov (United States)

Willner, M.; Herzen, J.; Grandl, S.; Auweter, S.; Mayr, D.; Hipp, A.; Chabior, M.; Sarapata, A.; Achterhold, K.; Zanette, I.; Weitkamp, T.; Sztrókay, A.; Hellerhoff, K.; Reiser, M.; Pfeiffer, F.

2014-04-01

X-ray phase-contrast imaging has received growing interest in recent years due to its high capability in visualizing soft tissue. Breast imaging became the focus of particular attention as it is considered the most promising candidate for a first clinical application of this contrast modality. In this study, we investigate quantitative breast tissue characterization using grating-based phase-contrast computed tomography (CT) at conventional polychromatic x-ray sources. Different breast specimens have been scanned at a laboratory phase-contrast imaging setup and were correlated to histopathology. Ascertained tumor types include phylloides tumor, fibroadenoma and infiltrating lobular carcinoma. Identified tissue types comprising adipose, fibroglandular and tumor tissue have been analyzed in terms of phase-contrast Hounsfield units and are compared to high-quality, high-resolution data obtained with monochromatic synchrotron radiation, as well as calculated values based on tabulated tissue properties. The results give a good impression of the method’s prospects and limitations for potential tumor detection and the associated demands on such a phase-contrast breast CT system. Furthermore, the evaluated quantitative tissue values serve as a reference for simulations and the design of dedicated phantoms for phase-contrast mammography.

Cine MR imaging of valvular heart disease

International Nuclear Information System (INIS)

Underwood, S.R.; Firmin, D.N.; Mohiaddin, R.H.; Klipstein, R.H.; Bogren, H.G.; Rees, R.S.O.; Longmore, D.B.

1987-01-01

Cine MR imaging shows details of cardiac valve motion and the turbulence caused by regurgitation and stenosis. In 30 patients, the area of turbulence proximal to regurgitant valves correlated well with the regurgitant fraction measured from right and left ventricular stroke volumes. Turbulence distal to stenotic valves did not correlate with the pressure gradient because abnormal valves that were not stenosed produced turbulence. Valve motion and the presence of thrombus were easier to assess than in conventional images. Cine MR imaging provides an important addition to conventional imaging in valvular regurgitation, but pressure gradients cannot be assessed in valvular stenosis

Sida y toma de conciencia: un cine comprometido

Directory of Open Access Journals (Sweden)

Eugenio Núñez Ang

2009-01-01

Full Text Available Se aborda el tema de personajes gay, durante mucho tiempo eliminados de la historia del cine; tratados como raros, enfermos mentales, o bien para burlarse de ellos. Con la aparición del sida y las luchas del movimiento gay, la perspectiva cambia y el cine aborda problemas humanos, ajenos a una preferencia sexual estigmatizada. Se hace hincapié en el sida y la toma de conciencia, tanto para la población gay como para los otros.

Sexualidad violenta en el cine de Kim Ki-duk

Directory of Open Access Journals (Sweden)

Daniel Muñoz Ruiz

2011-07-01

Full Text Available En sus más de 110 años de vida el cine ha representado la sexualidad humana en todas sus modalidades y desde los más variados puntos de vista. El cine de Kim Ki-duk ha sorprendido y escandalizado al público por su crudeza y, a veces, excesiva violencia. El director surcoreano ha explorado a lo largo de su filmografía el tema del sexo siempre desde puntos de vista dramáticos y hasta truculentos. En sus películas la mayoría de las relaciones sexuales carecen de amor y afecto. Nunca son placenteras. La violación, la prostitución, la violencia de género y las frustraciones sexuales son temas recurrentes en su cine.

Intracardiac flow patterns studied by cine MR flow imaging

International Nuclear Information System (INIS)

Underwood, S.R.; Firmin, D.N.; Klipstein, R.H.; Rees, R.S.O.; Longmore, D.B.

1986-01-01

Velocity mapping by means of cine-MR imaging allows accurate measurement of velocity and flow within the cardiovascular system. A cine display and color coding simplify interpretation. The author have used the technique in a variety of patients to illustrate its potential. Velocity mapping in coronary artery by pass grafts in six patients provided a measure of graft function. Coronary artery velocities were measured in three subjects. Flow was measured through defects in the atrial septum, the ventricular septum, and a Gerbode defect. Velocity was reduced distal to coarctation of the aorta and was increased at the level of a partial venous occlusion by thrombosis. In a patient with isomerism, velocity mapping in the central vessels aided interpretation. Cine-MR imaging velocity mapping combined with conventional imaging yields important functional information on the cardiovascular system

Origins of phase contrast in the atomic force microscope in liquids

OpenAIRE

Melcher, John; Carrasco, Carolina; Xu, Xianfan; Carrascosa, Jose L; Gomez-Herrero, Julio; Jose de Pablo, Pedro; Raman, Arvind

2009-01-01

We study the physical origins of phase contrast in dynamic atomic force microscopy (dAFM) in liquids where low-stiffness microcantilever probes are often used for nanoscale imaging of soft biological samples with gentle forces. Under these conditions, we show that the phase contrast derives primarily from a unique energy flow channel that opens up in liquids due to the momentary excitation of higher eigenmodes. Contrary to the common assumption, phase-contrast images in liquids using soft mic...

Motion Correction using Coil Arrays (MOCCA) for Free-Breathing Cardiac Cine MRI

Science.gov (United States)

Hu, Peng; Hong, Susie; Moghari, Mehdi H.; Goddu, Beth; Goepfert, Lois; Kissinger, Kraig V.; Hauser, Thomas H.; Manning, Warren J; Nezafat, Reza

2014-01-01

In this study, we present a motion compensation technique based on coil arrays (MOCCA) and evaluate its application in free-breathing respiratory self-gated cine MRI. MOCCA takes advantages of the fact that motion-induced changes in k-space signal are modulated by individual coil sensitivity profiles. In the proposed implementation of MOCCA self-gating for free-breathing cine MRI, the k-space center line is acquired at the beginning of each k-space segment for each cardiac cycle with 4 repetitions. For each k-space segment, the k-space center line acquired immediately before was used to select one of the 4 acquired repetitions to be included in the final self-gated cine image by calculating the cross-correlation between the k-space center line with a reference line. The proposed method was tested on a cohort of healthy adult subjects for subjective image quality and objective blood-myocardium border sharpness. The method was also tested on a cohort of patients to compare the left and right ventricular volumes and ejection fraction measurements with that of standard breath-hold cine MRI. Our data indicate that the proposed MOCCA method provides significantly improved image quality and sharpness compared to free-breathing cine without respiratory self-gating, and provides similar volume measurements compared with breath-hold cine MRI. PMID:21773986

Accuracy of right and left ventricular functional assessment by short-axis vs axial cine steady-state free-precession magnetic resonance imaging: intrapatient correlation with main pulmonary artery and ascending aorta phase-contrast flow measurements.

Science.gov (United States)

James, Susan H; Wald, Rachel; Wintersperger, Bernd J; Jimenez-Juan, Laura; Deva, Djeven; Crean, Andrew M; Nguyen, Elsie; Paul, Narinder S; Ley, Sebastian

2013-08-01

The left ventricle (LV) is routinely assessed with cardiac magnetic resonance imaging (MRI) by using short-axis orientation; it remains unclear whether the right ventricle (RV) can also be adequately assessed in this orientation or whether dedicated axial orientation is required. We used phase-contrast (PC) flow measurements in the main pulmonary artery (MPA) and the ascending aorta (Aorta) as nonvolumetric standard of reference and compared RV and LV volumes in short-axis and axial orientations. A retrospective analysis identified 30 patients with cardiac MRI data sets. Patients underwent MRI (1.5 T or 3 T), with retrospectively gated cine steady-state free-precession in axial and short-axis orientations. PC flow analyses of MPA and Aorta were used as the reference measure of RV and LV output. There was a high linear correlation between MPA-PC flow and RV-stroke volume (SV) short axis (r = 0.9) and RV-SV axial (r = 0.9). Bland-Altman analysis revealed a mean offset of 1.4 mL for RV axial and -2.3 mL for RV-short-axis vs MPA-PC flow. There was a high linear correlation between Aorta-PC flow and LV-SV short-axis (r = 0.9) and LV-SV axial (r = 0.9). Bland-Altman analysis revealed a mean offset of 4.8 m for LV short axis and 7.0 mL for LV axial vs Aorta-PC flow. There was no significant difference (P = .6) between short-axis-LV SV and short-axis-RV SV. No significant impact of the slice acquisition orientation for determination of RV and LV stroke volumes was found. Therefore, cardiac magnetic resonance workflow does not need to be extended by an axial data set for patients without complex cardiac disease for assessment of biventricular function and volumes. Copyright © 2013 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

Estimation of cardiac motion in cine-MRI sequences by correlation transform optical flow of monogenic features distance

Science.gov (United States)

Gao, Bin; Liu, Wanyu; Wang, Liang; Liu, Zhengjun; Croisille, Pierre; Delachartre, Philippe; Clarysse, Patrick

2016-12-01

Cine-MRI is widely used for the analysis of cardiac function in clinical routine, because of its high soft tissue contrast and relatively short acquisition time in comparison with other cardiac MRI techniques. The gray level distribution in cardiac cine-MRI is relatively homogenous within the myocardium, and can therefore make motion quantification difficult. To ensure that the motion estimation problem is well posed, more image features have to be considered. This work is inspired by a method previously developed for color image processing. The monogenic signal provides a framework to estimate the local phase, orientation, and amplitude, of an image, three features which locally characterize the 2D intensity profile. The independent monogenic features are combined into a 3D matrix for motion estimation. To improve motion estimation accuracy, we chose the zero-mean normalized cross-correlation as a matching measure, and implemented a bilateral filter for denoising and edge-preservation. The monogenic features distance is used in lieu of the color space distance in the bilateral filter. Results obtained from four realistic simulated sequences outperformed two other state of the art methods even in the presence of noise. The motion estimation errors (end point error) using our proposed method were reduced by about 20% in comparison with those obtained by the other tested methods. The new methodology was evaluated on four clinical sequences from patients presenting with cardiac motion dysfunctions and one healthy volunteer. The derived strain fields were analyzed favorably in their ability to identify myocardial regions with impaired motion.

Simultaneous static and cine nonenhanced MR angiography using radial sampling and highly constrained back projection reconstruction.

Science.gov (United States)

Koktzoglou, Ioannis; Mistretta, Charles A; Giri, Shivraman; Dunkle, Eugene E; Amin, Parag; Edelman, Robert R

2014-10-01

To describe a pulse sequence for simultaneous static and cine nonenhanced magnetic resonance angiography (NEMRA) of the peripheral arteries. The peripheral arteries of 10 volunteers and 6 patients with peripheral arterial disease (PAD) were imaged with the proposed cine NEMRA sequence on a 1.5 Tesla (T) system. The impact of multi-shot imaging and highly constrained back projection (HYPR) reconstruction was examined. The propagation rate of signal along the length of the arterial tree in the cine nonenhanced MR angiograms was quantified. The cine NEMRA sequence simultaneously provided a static MR angiogram showing vascular anatomy as well as a cine display of arterial pulse wave propagation along the entire length of the peripheral arteries. Multi-shot cine NEMRA improved temporal resolution and reduced image artifacts. HYPR reconstruction improved image quality when temporal reconstruction footprints shorter than 100 ms were used (P cine NEMRA was slower in patients with PAD than in volunteers. Simultaneous static and cine NEMRA of the peripheral arteries is feasible. Multi-shot acquisition and HYPR reconstruction can be used to improve arterial conspicuity and temporal resolution. Copyright © 2013 Wiley Periodicals, Inc.

Three-dimensional cine MRI in free-breathing infants and children with congenital heart disease

Energy Technology Data Exchange (ETDEWEB)

Seeger, Achim; Fenchel, Michael C.; Kramer, Ulrich; Bretschneider, Christiane; Doering, Joerg; Claussen, Claus D.; Miller, Stephan [University of Tuebingen (Germany). Department of Diagnostic and Interventional Radiology; Greil, Gerald F. [St. Thomas Hospital, Division of Imaging Sciences, King' s College London (United Kingdom); Martirosian, Petros [University of Tuebingen, Section of Experimental Radiology, Tuebingen (Germany); Sieverding, Ludger [University of Tuebingen, Department of Pediatric Cardiology, Tuebingen (Germany)

2009-12-15

Patients with congenital heart disease frequently have complex cardiac and vascular malformations requiring detailed non-invasive diagnostic evaluation including functional parameters. To evaluate the morphological and functional information provided by a novel 3-D cine steady-state free-precession (SSFP) sequence. Twenty consecutive children (mean age 2.2 years, nine boys) were examined using a 1.5-T MR system including 2-D cine gradient-recalled-echo sequences, static 3-D SSFP and 3-D cine SSFP sequences. Measurement of ventricular structures and volumes showed close agreement between the 3-D cine SSFP sequence and the 2-D cine gradient-recalled-echo and static 3-D SSFP sequences (left ventricular volumes mean difference 1.0-1.9 ml and 8.8-11.4%, respectively; right ventricular volumes 1.7-2.1 ml and 9.9-16.9%, respectively). No systematic bias was observed. 3-D cine MRI provides anatomic as well as functional information with sufficient spatial and temporal resolution in free-breathing infants with congenital heart disease. (orig.)

Three-dimensional cine MRI in free-breathing infants and children with congenital heart disease

International Nuclear Information System (INIS)

Seeger, Achim; Fenchel, Michael C.; Kramer, Ulrich; Bretschneider, Christiane; Doering, Joerg; Claussen, Claus D.; Miller, Stephan; Martirosian, Petros; Sieverding, Ludger

2009-01-01

Patients with congenital heart disease frequently have complex cardiac and vascular malformations requiring detailed non-invasive diagnostic evaluation including functional parameters. To evaluate the morphological and functional information provided by a novel 3-D cine steady-state free-precession (SSFP) sequence. Twenty consecutive children (mean age 2.2 years, nine boys) were examined using a 1.5-T MR system including 2-D cine gradient-recalled-echo sequences, static 3-D SSFP and 3-D cine SSFP sequences. Measurement of ventricular structures and volumes showed close agreement between the 3-D cine SSFP sequence and the 2-D cine gradient-recalled-echo and static 3-D SSFP sequences (left ventricular volumes mean difference 1.0-1.9 ml and 8.8-11.4%, respectively; right ventricular volumes 1.7-2.1 ml and 9.9-16.9%, respectively). No systematic bias was observed. 3-D cine MRI provides anatomic as well as functional information with sufficient spatial and temporal resolution in free-breathing infants with congenital heart disease. (orig.)

Characterization of a high-energy in-line phase contrast tomosynthesis prototype.

Science.gov (United States)

Wu, Di; Yan, Aimin; Li, Yuhua; Wong, Molly D; Zheng, Bin; Wu, Xizeng; Liu, Hong

2015-05-01

In this research, a high-energy in-line phase contrast tomosynthesis prototype was developed and characterized through quantitative investigations and phantom studies. The prototype system consists of an x-ray source, a motorized rotation stage, and a CMOS detector with a pixel pitch of 0.05 mm. The x-ray source was operated at 120 kVp for this study, and the objects were mounted on the rotation stage 76.2 cm (R1) from the source and 114.3 cm (R2) from the detector. The large air gap between the object and detector guarantees sufficient phase-shift effects. The quantitative evaluation of this prototype included modulation transfer function and noise power spectrum measurements conducted under both projection mode and tomosynthesis mode. Phantom studies were performed including three custom designed phantoms with complex structures: a five-layer bubble wrap phantom, a fishbone phantom, and a chicken breast phantom with embedded fibrils and mass structures extracted from an ACR phantom. In-plane images of the phantoms were acquired to investigate their image qualities through observation, intensity profile plots, edge enhancement evaluations, and/or contrast-to-noise ratio calculations. In addition, the robust phase-attenuation duality (PAD)-based phase retrieval method was applied to tomosynthesis for the first time in this research. It was utilized as a preprocessing method to fully exhibit phase contrast on the angular projection before reconstruction. The resolution and noise characteristics of this high-energy in-line phase contrast tomosynthesis prototype were successfully investigated and demonstrated. The phantom studies demonstrated that this imaging prototype can successfully remove the structure overlapping in phantom projections, obtain delineate interfaces, and achieve better contrast-to-noise ratio after applying phase retrieval to the angular projections. This research successfully demonstrated a high-energy in-line phase contrast tomosynthesis

Phase-contrast X-ray imaging using an X-ray interferometer for biological imaging

Energy Technology Data Exchange (ETDEWEB)

Momose, Atsushi; Koyama, Ichiro [Tokyo Univ., Dept. of Applied Physics, Tokyo (Japan); Takeda, Tohoru; Itai, Yuji [Tsukuba Univ., Inst. of Clinical Medicine, Tsukuba, Ibaraki (Japan); Yoneyama, Akio [Hitachi Ltd., Advanced Research Laboratory, Saitama (Japan)

2002-04-01

The potential of phase-contrast X-ray imaging using an X-ray interferometer is discussed comparing with other phase-contrast X-ray imaging methods, and its principle of contrast generation is presented including the case of phase-contrast X-ray computed tomography. The status of current instrumentation is described and perspectives for practical applications are discussed. (author)

Evaluation of potential internal target volume of liver tumors using cine-MRI

Energy Technology Data Exchange (ETDEWEB)

Akino, Yuichi, E-mail: akino@radonc.med.osaka-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 5650871, Japan and Miyakojima IGRT Clinic, Miyakojima-ku, Osaka 5340021 (Japan); Oh, Ryoong-Jin; Masai, Norihisa; Shiomi, Hiroya; Inoue, Toshihiko [Miyakojima IGRT Clinic, Miyakojima-ku, Osaka 5340021 (Japan)

2014-11-01

Purpose: Four-dimensional computed tomography (4DCT) is widely used for evaluating moving tumors, including lung and liver cancers. For patients with unstable respiration, however, the 4DCT may not visualize tumor motion properly. High-speed magnetic resonance imaging (MRI) sequences (cine-MRI) permit direct visualization of respiratory motion of liver tumors without considering radiation dose exposure to patients. Here, the authors demonstrated a technique for evaluating internal target volume (ITV) with consideration of respiratory variation using cine-MRI. Methods: The authors retrospectively evaluated six patients who received stereotactic body radiotherapy (SBRT) to hepatocellular carcinoma. Before acquiring planning CT, sagittal and coronal cine-MRI images were acquired for 30 s with a frame rate of 2 frames/s. The patient immobilization was conducted under the same condition as SBRT. Planning CT images were then acquired within 15 min from cine-MRI image acquisitions, followed by a 4DCT scan. To calculate tumor motion, the motion vectors between two continuous frames of cine-MRI images were calculated for each frame using the pyramidal Lucas–Kanade method. The target contour was delineated on one frame, and each vertex of the contour was shifted and copied onto the following frame using neighboring motion vectors. 3D trajectory data were generated with the centroid of the contours on sagittal and coronal images. To evaluate the accuracy of the tracking method, the motion of clearly visible blood vessel was analyzed with the motion tracking and manual detection techniques. The target volume delineated on the 50% (end-exhale) phase of 4DCT was translated with the trajectory data, and the distribution of the occupancy probability of target volume was calculated as potential ITV (ITV {sub Potential}). The concordance between ITV {sub Potential} and ITV estimated with 4DCT (ITV {sub 4DCT}) was evaluated using the Dice’s similarity coefficient (DSC). Results

El poder en el cine

OpenAIRE

Brisset Mart??n, Demetrio E.

2008-01-01

Desde la antropolog??a visual, se aborda la faceta del Poder relativa a sus diversas manifestaciones. Entre ellas, elegimos el cine, especialmente su g??nero de drama judicial, y analizamos comparativamente El proceso f??lmico de Welles y la novela de Kafka.

SU-E-J-234: Application of a Breathing Motion Model to ViewRay Cine MR Images

International Nuclear Information System (INIS)

O’Connell, D. P.; Thomas, D. H.; Dou, T. H.; Lamb, J. M.; Yang, L.; Low, D. A.

2015-01-01

Purpose: A respiratory motion model previously used to generate breathing-gated CT images was used with cine MR images. Accuracy and predictive ability of the in-plane models were evaluated. Methods: Sagittalplane cine MR images of a patient undergoing treatment on a ViewRay MRI/radiotherapy system were acquired before and during treatment. Images were acquired at 4 frames/second with 3.5 × 3.5 mm resolution and a slice thickness of 5 mm. The first cine frame was deformably registered to following frames. Superior/inferior component of the tumor centroid position was used as a breathing surrogate. Deformation vectors and surrogate measurements were used to determine motion model parameters. Model error was evaluated and subsequent treatment cines were predicted from breathing surrogate data. A simulated CT cine was created by generating breathing-gated volumetric images at 0.25 second intervals along the measured breathing trace, selecting a sagittal slice and downsampling to the resolution of the MR cines. A motion model was built using the first half of the simulated cine data. Model accuracy and error in predicting the remaining frames of the cine were evaluated. Results: Mean difference between model predicted and deformably registered lung tissue positions for the 28 second preview MR cine acquired before treatment was 0.81 +/− 0.30 mm. The model was used to predict two minutes of the subsequent treatment cine with a mean accuracy of 1.59 +/− 0.63 mm. Conclusion: Inplane motion models were built using MR cine images and evaluated for accuracy and ability to predict future respiratory motion from breathing surrogate measurements. Examination of long term predictive ability is ongoing. The technique was applied to simulated CT cines for further validation, and the authors are currently investigating use of in-plane models to update pre-existing volumetric motion models used for generation of breathing-gated CT planning images

Depiction of blood vessels by x-ray phase contrast

Energy Technology Data Exchange (ETDEWEB)

Momose, Atsushi [School of Engineering, University of Tokyo, Tokyo (Japan); Takeda, Tohoru; Itai, Yuji [Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki (Japan)

2001-04-01

Blood vessels in livers of a mouse and a rat were depicted by phase-contrast x-ray imaging with an x-ray interferometer without using contrast agents. X-ray interference patterns were converted to image mapping x-ray phase shift caused by the livers using the technique of phase-shifting x-ray interferometry. The arteries and veins to and from the livers were tied before excision in order to prevent blood from flowing out of the liver. The x-ray phase shift caused by blood was substantially different from that caused by other soft sues, and consequently trees of blood vessels were revealed in the images. Vessels of diameter smaller than 0.1 mm were detected. This result suggests new possibilities for investigating vascular systems. (author)

Atrapar la emoción: Hollywood y el Grupo Dogma 95 ante el cine digital

Directory of Open Access Journals (Sweden)

Marzal Felici, José Javier

2003-03-01

Full Text Available La tecnología del cine digital representa, no sólo nuevas formas de gestionar y organizar la producción cinematográfica, sino sobre todo abre la puerta para la exploración de nuevas formas de construcción del relato. En primer lugar, realizaremos una valoración general de lo que está suponiendo la «migración digital» para la industria del cine. Esto pasa por reflexionar sobre la importancia de la tecnología en la historia del cine y revisar las transformaciones que se están produciendo en la actualidad. Veremos cómo la construcción de mundos virtuales en el cine más industrial se enfrenta al reto de la «captura» de la emoción. Finalizaremos este bloque con una caracterización del cine hollywoodiense que constituye un «cine de atracciones»...

High spatial and temporal resolution retrospective cine cardiovascular magnetic resonance from shortened free breathing real-time acquisitions.

Science.gov (United States)

Xue, Hui; Kellman, Peter; Larocca, Gina; Arai, Andrew E; Hansen, Michael S

2013-11-14

Cine cardiovascular magnetic resonance (CMR) is challenging in patients who cannot perform repeated breath holds. Real-time, free-breathing acquisition is an alternative, but image quality is typically inferior. There is a clinical need for techniques that achieve similar image quality to the segmented cine using a free breathing acquisition. Previously, high quality retrospectively gated cine images have been reconstructed from real-time acquisitions using parallel imaging and motion correction. These methods had limited clinical applicability due to lengthy acquisitions and volumetric measurements obtained with such methods have not previously been evaluated systematically. This study introduces a new retrospective reconstruction scheme for real-time cine imaging which aims to shorten the required acquisition. A real-time acquisition of 16-20s per acquired slice was inputted into a retrospective cine reconstruction algorithm, which employed non-rigid registration to remove respiratory motion and SPIRiT non-linear reconstruction with temporal regularization to fill in missing data. The algorithm was used to reconstruct cine loops with high spatial (1.3-1.8 × 1.8-2.1 mm²) and temporal resolution (retrospectively gated, 30 cardiac phases, temporal resolution 34.3 ± 9.1 ms). Validation was performed in 15 healthy volunteers using two different acquisition resolutions (256 × 144/192 × 128 matrix sizes). For each subject, 9 to 12 short axis and 3 long axis slices were imaged with both segmented and real-time acquisitions. The retrospectively reconstructed real-time cine images were compared to a traditional segmented breath-held acquisition in terms of image quality scores. Image quality scoring was performed by two experts using a scale between 1 and 5 (poor to good). For every subject, LAX and three SAX slices were selected and reviewed in the random order. The reviewers were blinded to the reconstruction approach and acquisition protocols and

Monitoring tumor motion with on-line mega-voltage cone-beam computed tomography imaging in a cine mode

International Nuclear Information System (INIS)

Reitz, Bodo; Gayou, Olivier; Parda, David S; Miften, Moyed

2008-01-01

Accurate daily patient localization is becoming increasingly important in external-beam radiotherapy (RT). Mega-voltage cone-beam computed tomography (MV-CBCT) utilizing a therapy beam and an on-board electronic portal imager can be used to localize tumor volumes and verify the patient's position prior to treatment. MV-CBCT produces a static volumetric image and therefore can only account for inter-fractional changes. In this work, the feasibility of using the MV-CBCT raw data as a fluoroscopic series of portal images to monitor tumor changes due to e.g. respiratory motion was investigated. A method was developed to read and convert the CB raw data into a cine. To improve the contrast-to-noise ratio on the MV-CB projection data, image post-processing with filtering techniques was investigated. Volumes of interest from the planning CT were projected onto the MV-cine. Because of the small exposure and the varying thickness of the patient depending on the projection angle, soft-tissue contrast was limited. Tumor visibility as a function of tumor size and projection angle was studied. The method was well suited in the upper chest, where motion of the tumor as well as of the diaphragm could be clearly seen. In the cases of patients with non-small cell lung cancer with medium or large tumor masses, we verified that the tumor mass was always located within the PTV despite respiratory motion. However for small tumors the method is less applicable, because the visibility of those targets becomes marginal. Evaluation of motion in non-superior-inferior directions might also be limited for small tumor masses. Viewing MV-CBCT data in a cine mode adds to the utility of MV-CBCT for verification of tumor motion and for deriving individualized treatment margins

Feasibility of vocal fold abduction and adduction assessment using cine-MRI

Energy Technology Data Exchange (ETDEWEB)

Baki, Marina Mat [National University of Malaysia, Faculty of Medicine, Kuala Lumpur (Malaysia); Menys, Alex; Morley, Simon; Beale, Timothy [University College London, Centre for Medical Imaging, London (United Kingdom); Atkinson, David; Punwani, Shonit [University College London, Centre for Medical Imaging, London (United Kingdom); Royal National Throat Nose Ear Hospital, University College London Hospital NHS Trust, London (United Kingdom); Bassett, Paul [University College London, London (United Kingdom); Sandhu, Guri [Charing Cross Hospital, Imperial College Healthcare NHS Trust, London (United Kingdom); Naduvilethil, Georgekutty; Stevenson, Nicola [Royal National Throat Nose Ear Hospital, University College London Hospital NHS Trust, London (United Kingdom); Birchall, Martin A. [Royal National Throat Nose Ear Hospital, University College London Hospital NHS Trust, London (United Kingdom); University of California, Davis, Department of Otolaryngology, Davis, CA (United States); University College London, Ear Institute, London (United Kingdom)

2017-02-15

Determine feasibility of vocal fold (VF) abduction and adduction assessment by cine magnetic resonance imaging (cine-MRI) Cine-MRI of the VF was performed on five healthy and nine unilateral VF paralysis (UVFP) participants using an axial gradient echo acquisition with temporal resolution of 0.7 s. VFs were continuously imaged with cine-MRI during a 10-s period of quiet respiration and phonation. Scanning was repeated twice within an individual session and then once again at a 1-week interval. Asymmetry of VF position during phonation (VF phonation asymmetry, VFPa) and respiration (VF respiration asymmetry, VFRa) was determined. Percentage reduction in total glottal area between respiration and phonation (VF abduction potential, VFAP) was derived to measure overall mobility. An un-paired t-test was used to compare differences between groups. Intra-session, inter-session and inter-reader repeatability of the quantitative metrics was evaluated using intraclass correlation coefficient (ICC). VF position asymmetry (VFPa and VFRa) was greater (p=0.012; p=0.001) and overall mobility (VFAP) was lower (p=0.008) in UVFP patients compared with healthy participants. ICC of repeatability of all metrics was good, ranged from 0.82 to 0.95 except for the inter-session VFPa (0.44). Cine-MRI is feasible for assessing VF abduction and adduction. Derived quantitative metrics have good repeatability. (orig.)

Feasibility of vocal fold abduction and adduction assessment using cine-MRI

International Nuclear Information System (INIS)

Baki, Marina Mat; Menys, Alex; Morley, Simon; Beale, Timothy; Atkinson, David; Punwani, Shonit; Bassett, Paul; Sandhu, Guri; Naduvilethil, Georgekutty; Stevenson, Nicola; Birchall, Martin A.

2017-01-01

Determine feasibility of vocal fold (VF) abduction and adduction assessment by cine magnetic resonance imaging (cine-MRI) Cine-MRI of the VF was performed on five healthy and nine unilateral VF paralysis (UVFP) participants using an axial gradient echo acquisition with temporal resolution of 0.7 s. VFs were continuously imaged with cine-MRI during a 10-s period of quiet respiration and phonation. Scanning was repeated twice within an individual session and then once again at a 1-week interval. Asymmetry of VF position during phonation (VF phonation asymmetry, VFPa) and respiration (VF respiration asymmetry, VFRa) was determined. Percentage reduction in total glottal area between respiration and phonation (VF abduction potential, VFAP) was derived to measure overall mobility. An un-paired t-test was used to compare differences between groups. Intra-session, inter-session and inter-reader repeatability of the quantitative metrics was evaluated using intraclass correlation coefficient (ICC). VF position asymmetry (VFPa and VFRa) was greater (p=0.012; p=0.001) and overall mobility (VFAP) was lower (p=0.008) in UVFP patients compared with healthy participants. ICC of repeatability of all metrics was good, ranged from 0.82 to 0.95 except for the inter-session VFPa (0.44). Cine-MRI is feasible for assessing VF abduction and adduction. Derived quantitative metrics have good repeatability. (orig.)

Characterisation of phase evolution under load by means of phase contrast imaging using synchrotron radiation

International Nuclear Information System (INIS)

Besseghini, S.; Stortiero, F.; Carcano, G.; Villa, E.; Mancini, L.; Tromba, G.; Zanini, F.; Montanari, F.; Airoldi, G.

2003-01-01

Phase contrast radiography (PCR) is a quite novel technique that is collecting increasing attention due to the possibility to obtain image information in presence of very small differences in the densities of the materials under analysis. Phase contrast imaging (PCI) has some specific advantage when compared with common microscopic techniques: (a) no special preparation of the sample is needed (b) the simultaneously investigated area is very large and (c) it allows the setting up of complex experimental apparatus. The results here presented are a good evidence of these three advantages. In this paper, we report on the application of phase contrast imaging in the study of the phase evolution during pseudoelastic transformation in the NiTiCu shape memory alloys (SMAs). The investigation was undertaken with the aim to identify some modification of the structure taking place at the end of the transformation plateau in the pseudoelastic behaviour of the alloy

Magnetic resonance (MR) cine imaging of the human heart

International Nuclear Information System (INIS)

Waterton, J.C.

1985-01-01

A novel approach has been developed for MR cine imaging of the human heart by a modified ECG-gated 2DFT method. A pulse sequence has been devised to minimise the effects of saturation which can be anticipated in sequences that require rapid pulsing. Five frames are produced at the same anatomical level at predetermined intervals during the cardiac cycle. The total time taken to achieve this data is 8 minutes. Additional frames can be interleaved by repeating the sequence with an ECG-gated delay. The anatomical sections, which can be in any orthogonal plane, are then displayed as a cine loop. Cine display in the coronal plane has been used to examine 10 volunteers and 12 patients. In addition to the morphological feature displayed in single slice ECG-gated imaging, areas of dyskinesia can be detected and subjective estimates have been made of left ventricular function. (author)

EL CINE ESPAÑOL COMO FUENTE DOCUMENTAL PARA EL ESTUDIO DE LOS BARRIOS MARGINALES

Directory of Open Access Journals (Sweden)

Aramis López Juan

2008-01-01

Full Text Available El cine como arte nuevo y técnico se instala en una sociedad moderna que tiene una percepción del mundo basada en la imagen. El cine y la fotografía son los introductores de esta modalidad perceptiva de la modernidad. Esta experiencia sensorial sitúa al hombre en un universo más amplio. El hombre contemporáneo comprende los mecanismos representativos del cine, sus códigos, sus metáforas e iconos. El cine ha nacido al mismo tiempo que los abuelos de los espectadores actuales, ha crecido con sus padres, y es conocido y comprendido universalmente

Evaluation of aortic distensibility using cine MR imaging

International Nuclear Information System (INIS)

Takahashi, Masashi; Murata, Kiyoshi; Mori, Masayuki

1992-01-01

Regional aortic distensibility was measured noninvasively using cine MR imaging to determine whether it correlates with aging or risk of coronary artery disease (CAD). Twenty-two patients with CAD confirmed by angiography and 33 without CAD underwent cine MR imaging. Thirty-two sequential images were obtained in one cardiac cycle. The cross sectional area of the descending thoracic aorta was measured on both diastolic (A) and systolic (A') images. Aortic distensibility (A.D.) was calculated from the following equation: A.D.=(A'-A)/A/ΔP.(ΔP represents pulse pressure). Results of a simple regression analysis showed that decreased regional aortic distensibility was significantly correlated with the age of the patients (r=-0.762, p<0.005). In addition, the parameter was lower in patients with CAD than those without CAD (p<0.05). In conclusion, regional aortic distensibility derived from cine MR imaging is a useful parameter to evaluate not only aging but also pathological atherosclerosis of the aorta. In addition, this parameter might have some potential to evaluate the prediction of CAD in patients with normal serum cholesterol. (author)

Dynamic Studies of Lung Fluid Clearance with Phase Contrast Imaging

International Nuclear Information System (INIS)

Kitchen, Marcus J.; Williams, Ivan; Irvine, Sarah C.; Morgan, Michael J.; Paganin, David M.; Lewis, Rob A.; Pavlov, Konstantin; Hooper, Stuart B.; Wallace, Megan J.; Siu, Karen K. W.; Yagi, Naoto; Uesugi, Kentaro

2007-01-01

Clearance of liquid from the airways at birth is a poorly understood process, partly due to the difficulties of observing and measuring the distribution of air within the lung. Imaging dynamic processes within the lung in vivo with high contrast and spatial resolution is therefore a major challenge. However, phase contrast X-ray imaging is able to exploit inhaled air as a contrast agent, rendering the lungs of small animals visible due to the large changes in the refractive index at air/tissue interfaces. In concert with the high spatial resolution afforded by X-ray imaging systems (<100 μm), propagation-based phase contrast imaging is ideal for studying lung development. To this end we have utilized intense, monochromatic synchrotron radiation, together with a fast readout CCD camera, to study fluid clearance from the lungs of rabbit pups at birth. Local rates of fluid clearance have been measured from the dynamic sequences using a single image phase retrieval algorithm

An initial study on the estimation of time-varying volumetric treatment images and 3D tumor localization from single MV cine EPID images

Energy Technology Data Exchange (ETDEWEB)

Mishra, Pankaj, E-mail: pankaj.mishra@varian.com; Mak, Raymond H.; Rottmann, Joerg; Bryant, Jonathan H.; Williams, Christopher L.; Berbeco, Ross I.; Lewis, John H. [Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Li, Ruijiang [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305 (United States)

2014-08-15

Purpose: In this work the authors develop and investigate the feasibility of a method to estimate time-varying volumetric images from individual MV cine electronic portal image device (EPID) images. Methods: The authors adopt a two-step approach to time-varying volumetric image estimation from a single cine EPID image. In the first step, a patient-specific motion model is constructed from 4DCT. In the second step, parameters in the motion model are tuned according to the information in the EPID image. The patient-specific motion model is based on a compact representation of lung motion represented in displacement vector fields (DVFs). DVFs are calculated through deformable image registration (DIR) of a reference 4DCT phase image (typically peak-exhale) to a set of 4DCT images corresponding to different phases of a breathing cycle. The salient characteristics in the DVFs are captured in a compact representation through principal component analysis (PCA). PCA decouples the spatial and temporal components of the DVFs. Spatial information is represented in eigenvectors and the temporal information is represented by eigen-coefficients. To generate a new volumetric image, the eigen-coefficients are updated via cost function optimization based on digitally reconstructed radiographs and projection images. The updated eigen-coefficients are then multiplied with the eigenvectors to obtain updated DVFs that, in turn, give the volumetric image corresponding to the cine EPID image. Results: The algorithm was tested on (1) Eight digital eXtended CArdiac-Torso phantom datasets based on different irregular patient breathing patterns and (2) patient cine EPID images acquired during SBRT treatments. The root-mean-squared tumor localization error is (0.73 ± 0.63 mm) for the XCAT data and (0.90 ± 0.65 mm) for the patient data. Conclusions: The authors introduced a novel method of estimating volumetric time-varying images from single cine EPID images and a PCA-based lung motion model

Routine cine-CMR for prosthesis-associated mitral regurgitation: a multicenter comparison to echocardiography.

Science.gov (United States)

Simprini, Lauren A; Afroz, Anika; Cooper, Mitchell A; Klem, Igor; Jensen, Christoph; Kim, Raymond J; Srichai, Monvadi B; Heitner, John F; Sood, Michael; Chandy, Elizabeth; Shah, Dipan J; Lopez-Mattei, Juan; Biederman, Robert W; Grizzard, John D; Fuisz, Anthon; Ghafourian, Kambiz; Farzaneh-Far, Afshin; Weinsaft, Jonathan

2014-09-01

Mitral regurgitation (MR) is an important complication after prosthetic mitral valve (PMV) implantation. Transthoracic echocardiography is widely used to screen for native MR, but can be limited with PMV. Cine-cardiac magnetic resonance (CMR) holds the potential for the non-invasive assessment of regurgitant severity based on MR-induced inter-voxel dephasing. The study aim was to evaluate routine cine-CMR for the visual assessment of PMV-associated MR. Routine cine-CMR was performed at nine sites. A uniform protocol was used to grade MR based on jet size in relation to the left atrium (mild 2/3). MR was graded in each long-axis orientation, with overall severity based on cumulative grade. Cine-CMR was also scored for MR density and pulmonary vein systolic flow reversal (PVSFR). Visual interpretation was compared to quantitative analysis in a single-center (derivation) cohort, and to transesophageal echocardiography (TEE) in a multicenter (validation) cohort. The population comprised 85 PMV patients (59% mechanical valves, 41% bioprostheses). Among the derivation cohort (n = 25), quantitative indices paralleled visual scores, with stepwise increases in jet size and density in relation to visually graded MR severity (both p = 0.001). Patients with severe MR had an almost three-fold increase in quantitative jet area (p = 0.002), and a two-fold increase in density (p = 0.04) than did other patients. Among the multicenter cohort, cine-CMR and TEE (Δ =. 2 ± 3 days) demonstrated moderate agreement (κ = 0.44); 64% of discordances differed by ≤ 1 grade (Δ = 1.2 ± 0.5). Using a TEE reference, cine-CMR yielded excellent diagnostic performance for severe MR (sensitivity, negative predictive value = 100%). Patients with visually graded severe MR also had more frequent PVSFR (p cine-CMR. Cine-CMR is useful for the assessment of PMV-associated MR, which manifests concordant quantitative and qualitative changes in size and density of inter-voxel dephasing. Visual MR

Roles femeninos en el cine de migraciones en España

Directory of Open Access Journals (Sweden)

María Jesús Alonso Seoane

2011-10-01

Full Text Available El estudio del cine como medio para el análisis sociológico es poco frecuente todavía en nuestro país. Existen numerosos artículos analizando el cine desde diversos ángulos, también el femenino, especialmente roles como el de la mujer fatal en el cine negro. Pero es menos habitual emplear este formato como parte de un método analítico del que extraer un reflejo social de lo que las pantallas proyectan y, a un tiempo, contribuyen a legitimar como base de una sociedad futura. No obstante, existen pocos medios que sean capaces de reflejar el gran cambio acaecido en la historia reciente de la sociedad española. Este interés documental incrementa su potencial al enfocar en primer plano a las mujeres. Este artículo es una contribución a estudiar un campo tan atractivo como es el cine de migraciones a través de la óptica de los imaginarios sociales.

Low-dose quantitative phase contrast medical CT

Science.gov (United States)

Mittone, A.; Bravin, A.; Coan, P.

2018-02-01

X-ray computed tomography (CT) is a powerful and routinely used clinical diagnostic technique, which is well tolerated by patients, and which provides high-resolution images and volumetric information about the body. However, two important limitations still affect this examination procedure: (1) its low sensitivity with respect to soft tissues, and (2) the hazards associated with x-ray exposure. Conventional radiology is based on the detection of the different photon absorption properties that characterize biological tissues, and thus the obtainable image contrast from soft and/or similar tissues is intrinsically limited. In this scenario, x-ray phase contrast imaging (XPCI) has been extensively tested and proven to overcome some of the main issues surrounding standard x-ray imaging. In addition to the absorption signal, XPCI relies on detecting the phase shifts induced by an object. Interestingly, as the order of magnitude of the phase contrast is higher than that of absorption, XPCI can, in principle, offer higher sensitivity at lower radiation doses. However, other technical aspects may counterbalance this gain, and an optimized setup and image processing solutions need to be implemented. The work presented here describes the strategies and developments we have realized, with the aim of controlling the radiation dose for the highly sensitive and quantitative XPCI-CT. Different algorithms for the phase retrieval and CT reconstruction of the XPCI data are presented. The CT algorithms we have implemented, namely the equally sloped tomography and the dictionary learning method, allow the image quality to be preserved while reducing the number of angular projections required by a factor of five. The results applied to breast imaging report accurate reconstructions at clinically compatible doses of the 3D distribution of the refractive properties of full human organs obtained by using three different phase retrieval methods. The described methodologies and the

ConCERNed for Humanity and Cine Club

CERN Document Server

ConCERNed for Humanity and Cine Club

2012-01-01

  Thursday 26 April 2012 at 20:00 CERN Council Chamber Sicko By Michael Moore (USA, 2007) 123 min, original version English; French subtitles. Documentary look at health care in the United States as provided by profit-oriented health maintenance organizations (HMOs) compared to free, universal care in Canada, the U.K., and France. Moore contrasts U.S. media reports on Canadian care with the experiences of Canadians in hospitals and clinics there. He interviews patients and doctors in the U.K. about cost, quality, and salaries. He examines why Nixon promoted HMOs in 1971, and why the Clintons’ reform effort failed in the 1990s. He talks to U.S. ex-pats in Paris about French services, and he takes three 9/11 clean-up volunteers, who developed respiratory problems, to Cuba for care. He asks of Americans, “Who are we?” Organisation : ConCERNed for Humanity Club and CERN CineClub Projection from DVD – entrance free – for info: http://cern.ch/C...

Tras los pasos del Cine en Ecuador: la producción nacional y políticas de apoyo

Directory of Open Access Journals (Sweden)

Violeta Yalilé Loaiza Ruiz

2015-12-01

Full Text Available Con el presente trabajo reflexionamos sobre el estado actual del cine ecuatoriano, la incidencia que en él tiene la actual Ley del Cine y la participación del Consejo Nacional del Cine en su financiación. Partimos de una historia del cine, desde sus comienzos en el último cuarto del siglo XIX, con las primeras filmaciones de Theodor Wolf, hasta la actualidad. Analizaremos las causas de las preferencias de los espectadores, la dicotomía entre cine documental y ficcional, a través de las más importantes películas realizadas en el país y su incidencia internacional. Para ello hemos utilizado la entrevista a tres de sus más importantes protagonistas/actores, Wilma Granda, Alex Schlenker y Santiago Carpio, para conocer su opinión del cine en Ecuador. El cine ecuatoriano sigue evolucionando pese a los obstáculos políticos y económicos que existentes y la fuerte competencia del cine extranjero, fundamentalmente de los Estados Unidos.

Zernike phase contrast cryo-electron tomography of whole bacterial cells.

Science.gov (United States)

Guerrero-Ferreira, Ricardo C; Wright, Elizabeth R

2014-01-01

Cryo-electron tomography (cryo-ET) provides three-dimensional (3D) structural information of bacteria preserved in a native, frozen-hydrated state. The typical low contrast of tilt-series images, a result of both the need for a low electron dose and the use of conventional defocus phase-contrast imaging, is a challenge for high-quality tomograms. We show that Zernike phase-contrast imaging allows the electron dose to be reduced. This limits movement of gold fiducials during the tilt series, which leads to better alignment and a higher-resolution reconstruction. Contrast is also enhanced, improving visibility of weak features. The reduced electron dose also means that more images at more tilt angles could be recorded, further increasing resolution. Copyright © 2013 Elsevier Inc. All rights reserved.

Phase-Contrast Hounsfield Units of Fixated and Non-Fixated Soft-Tissue Samples

Science.gov (United States)

Willner, Marian; Fior, Gabriel; Marschner, Mathias; Birnbacher, Lorenz; Schock, Jonathan; Braun, Christian; Fingerle, Alexander A.; Noël, Peter B.; Rummeny, Ernst J.; Pfeiffer, Franz; Herzen, Julia

2015-01-01

X-ray phase-contrast imaging is a novel technology that achieves high soft-tissue contrast. Although its clinical impact is still under investigation, the technique may potentially improve clinical diagnostics. In conventional attenuation-based X-ray computed tomography, radiological diagnostics are quantified by Hounsfield units. Corresponding Hounsfield units for phase-contrast imaging have been recently introduced, enabling a setup-independent comparison and standardized interpretation of imaging results. Thus far, the experimental values of few tissue types have been reported; these values have been determined from fixated tissue samples. This study presents phase-contrast Hounsfield units for various types of non-fixated human soft tissues. A large variety of tissue specimens ranging from adipose, muscle and connective tissues to liver, kidney and pancreas tissues were imaged by a grating interferometer with a rotating-anode X-ray tube and a photon-counting detector. Furthermore, we investigated the effects of formalin fixation on the quantitative phase-contrast imaging results. PMID:26322638

X-ray phase contrast imaging: From synchrotrons to conventional sources

International Nuclear Information System (INIS)

Olivo, A.; Castelli, E.

2014-01-01

Phase-based approaches can revolutionize X-ray imaging and remove its main limitation: poor image contrast arising from low attenuation differences. They exploit the unit decrement of the real part of the refractive index, typically 1000 times larger than the imaginary part driving attenuation. This increases the contrast of all details, and enables the detection of features classically considered 'X-ray invisible'. Following pioneering experiments dating back to the mid-sixties, X-ray phase contrast imaging 'exploded' in the mid-nineties, when third generation synchrotron sources became more widely available. Applications were proposed in fields as diverse as material science, palaeontology, biology, food science, cultural heritage preservation, and many others. Among these applications, medicine has been constantly considered the most important; among medical applications, mammography is arguably the one that attracted most attention. Applications to mammography were pioneered by the SYRMEP (SYnchrotron Radiation for MEdical Physics) group in Trieste, which was already active in the area through a combination of innovative ways to do imaging at synchrotrons and development of novel X-ray detectors. This pioneering phase led to the only clinical experience of phase contrast mammography on human patients, and spawned a number of ideas as to how these advances could be translated into clinical practice.

Relation of external surface to internal tumor motion studied with cine CT

International Nuclear Information System (INIS)

Chi, P.-C.M.; Balter, Peter; Luo Dershan; Mohan, Radhe; Pan Tinsu

2006-01-01

The accuracy of delivering gated-radiation therapy to lung tumors using an external respiratory surrogate relies on not only interfractional and intrafractional reproducibility, but also a strong correlation between external motion and internal tumor motion. The purpose of this work was to use the cine images acquired by four-dimensional computed tomography acquisition protocol to study the relation between external surface motion and internal tumor motion. The respiratory phase information of tumor motion and chest wall motion was measured on the cine images using a proposed region-of-interest (ROI) method and compared to measurement of an external respiratory monitoring device. On eight lung patient data sets, the phase shifts were measured between (1) the signal of a real-time positioning-management (RPM) respiratory monitoring device placed in the abdominal region and four surface locations on the chest wall (2) the RPM signal in the abdominal region and tumor motions, and (3) chest wall surface motions and tumor motions. Respiratory waveforms measured at different surface locations during the same respiratory cycle often varied and had significant phase shifts. Seven of the 8 patients showed the abdominal motion leading chest wall motion. The best correlation (smallest phase shift) was found between the abdominal motion and the superior-inferior (S-I) tumor motion. A wide range of phase shifts was observed between external surface motion and tumor anterior-posterior (A-P)/lateral motion. The result supported the placement of the RPM block in the abdominal region and suggested that during a gated therapy utilizing the RPM system, it is necessary to place the RPM block at the same location as it is during treatment simulation in order to reduce potential errors introduced by the position of the RPM block. Correlations between external motions and lateral/A-P tumor motions were inconclusive due to a combination of patient selection and the limitation of the ROI

Monte Carlo simulation of grating-based neutron phase contrast imaging at CPHS

International Nuclear Information System (INIS)

Zhang Ran; Chen Zhiqiang; Huang Zhifeng; Xiao Yongshun; Wang Xuewu; Wie Jie; Loong, C.-K.

2011-01-01

Since the launching of the Compact Pulsed Hadron Source (CPHS) project of Tsinghua University in 2009, works have begun on the design and engineering of an imaging/radiography instrument for the neutron source provided by CPHS. The instrument will perform basic tasks such as transmission imaging and computerized tomography. Additionally, we include in the design the utilization of coded-aperture and grating-based phase contrast methodology, as well as the options of prompt gamma-ray analysis and neutron-energy selective imaging. Previously, we had implemented the hardware and data-analysis software for grating-based X-ray phase contrast imaging. Here, we investigate Geant4-based Monte Carlo simulations of neutron refraction phenomena and then model the grating-based neutron phase contrast imaging system according to the classic-optics-based method. The simulated experimental results of the retrieving phase shift gradient information by five-step phase-stepping approach indicate the feasibility of grating-based neutron phase contrast imaging as an option for the cold neutron imaging instrument at the CPHS.

Motion-Corrected Real-Time Cine Magnetic Resonance Imaging of the Heart: Initial Clinical Experience.

Science.gov (United States)

Rahsepar, Amir Ali; Saybasili, Haris; Ghasemiesfe, Ahmadreza; Dolan, Ryan S; Shehata, Monda L; Botelho, Marcos P; Markl, Michael; Spottiswoode, Bruce; Collins, Jeremy D; Carr, James C

2018-01-01

Free-breathing real-time (RT) imaging can be used in patients with difficulty in breath-holding; however, RT cine imaging typically experiences poor image quality compared with segmented cine imaging because of low resolution. Here, we validate a novel unsupervised motion-corrected (MOCO) reconstruction technique for free-breathing RT cardiac images, called MOCO-RT. Motion-corrected RT uses elastic image registration to generate a single heartbeat of high-quality data from a free-breathing RT acquisition. Segmented balanced steady-state free precession (bSSFP) cine images and free-breathing RT images (Cartesian, TGRAPPA factor 4) were acquired with the same spatial/temporal resolution in 40 patients using clinical 1.5 T magnetic resonance scanners. The respiratory cycle was estimated using the reconstructed RT images, and nonrigid unsupervised motion correction was applied to eliminate breathing motion. Conventional segmented RT and MOCO-RT single-heartbeat cine images were analyzed to evaluate left ventricular (LV) function and volume measurements. Two radiologists scored images for overall image quality, artifact, noise, and wall motion abnormalities. Intraclass correlation coefficient was used to assess the reliability of MOCO-RT measurement. Intraclass correlation coefficient showed excellent reliability (intraclass correlation coefficient ≥ 0.95) of MOCO-RT with segmented cine in measuring LV function, mass, and volume. Comparison of the qualitative ratings indicated comparable image quality for MOCO-RT (4.80 ± 0.35) with segmented cine (4.45 ± 0.88, P = 0.215) and significantly higher than conventional RT techniques (3.51 ± 0.41, P cine (1.51 ± 0.90, P = 0.088 and 1.23 ± 0.45, P = 0.182) were not different. Wall motion abnormality ratings were comparable among different techniques (P = 0.96). The MOCO-RT technique can be used to process conventional free-breathing RT cine images and provides comparable quantitative assessment of LV function and volume

Cine dyscontractility index: A novel marker of mechanical dyssynchrony that predicts response to cardiac resynchronization therapy.

Science.gov (United States)

Werys, Konrad; Petryka-Mazurkiewicz, Joanna; Błaszczyk, Łukasz; Miśko, Jolanta; Śpiewak, Mateusz; Małek, Łukasz A; Mazurkiewicz, Łukasz; Miłosz-Wieczorek, Barbara; Marczak, Magdalena; Kubik, Agata; Dąbrowska, Agnieszka; Piątkowska-Janko, Ewa; Sawionek, Błażej; Wijesurendra, Rohan; Piechnik, Stefan K; Bogorodzki, Piotr

2016-12-01

To investigate whether magnetic resonance imaging (MRI) cine-derived dyssynchrony indices provide additional information compared to conventional tagged MRI (tMRI) acquisitions in heart failure patients undergoing cardiac resynchronization therapy (CRT). Patients scheduled for CRT (n = 52) underwent preprocedure MRI including cine and tMRI acquisitions. Segmental strain curves were calculated for both cine and tMRI to produce a range of standard indices for direct comparison between modalities. We also proposed and evaluated a novel index of "dyscontractility," which detects the presence of focal areas with paradoxically positive circumferential strain. Across conventional strain indices, there was only moderate-to-poor (R = 0.3-0.6) correlation between modalities; eight cine-derived indices showed statistically significant (P cine images (cine dyscontractility index, "CDI") was the single best predictor of clinical response to CRT (area under the curve AUC = 0.81, P Cine-derived strain indices offer potentially new information compared to tMRI. Specifically, the novel CDI is most strongly linked to response to cardiac resynchronization therapy in a contemporary patient cohort. It utilizes readily available MRI data, is relatively straightforward to process, and compares favorably with any conventional tagging index. J. Magn. Reson. Imaging 2016;44:1483-1492. © 2016 International Society for Magnetic Resonance in Medicine.

Cine magnetic resonance imaging for evaluation of cardiac structure and flow dynamics in congenital heart disease

International Nuclear Information System (INIS)

Akagi, Teiji; Kiyomatsu, Yumi; Ohara, Nobutoshi; Takagi, Junichi; Sato, Noboru; Kato, Hirohisa; Eto, Takaharu.

1989-01-01

Cine magnetic resonance imaging (Cine MRI) was performed in 20 patients aged 19 days to 13 years (mean 4.0 years), who had congenital heart disease confirmed at echocardiography or angiography. Prior to cine MRI, gated MRI was performed to evaluate for cardiac structure. Cine MRI was demonstrated by fast low fip angle shot imaging technique with a 30deg flip angle, 15 msec echo time, 30-40 msec pulse repetition time, and 128 x 128 acquisition matrix. Abnormalities of cardiac structure were extremely well defined in all patients by gated MRI. Intracardiac or intravascular blood flow were visualized in 17 (85%) of 20 patients by cine MRI. Left to right shunt flow through ventricular septal defect, atrial septal defect, and endocardial cushion defect were visualized with low signal intensity area. Low intensity jets flow through the site of re-coarctation of the aorta were also visualized. However, the good recording of cine MRI was not obtained because of artifacts in 3 of 20 patients (15%) who had severe congestive heart failure or respiratory arrhythmia. Gated MRI provides excellent visualization of fine structure, and cine MRI can provide high spatial resolution imaging of flow dynamic in a variety of congenital heart disease, noninvasively. (author)

Investigation of the imaging quality of synchrotron-based phase-contrast mammographic tomography

International Nuclear Information System (INIS)

Gureyev, T E; Mayo, S C; Nesterets, Ya I; Mohammadi, S; Menk, R H; Arfelli, F; Tromba, G; Lockie, D; Pavlov, K M; Kitchen, M J; Zanconati, F; Dullin, C

2014-01-01

We report the results of a systematic study of phase-contrast x-ray computed tomography in the propagation-based and analyser-based modes using specially designed phantoms and excised breast tissue samples. The study is aimed at the quantitative evaluation and subsequent optimization, with respect to detection of small tumours in breast tissue, of the effects of phase contrast and phase retrieval on key imaging parameters, such as spatial resolution, contrast-to-noise ratio, x-ray dose and a recently proposed ‘intrinsic quality’ characteristic which combines the image noise with the spatial resolution. We demonstrate that some of the methods evaluated in this work lead to substantial (more than 20-fold) improvement in the contrast-to-noise and intrinsic quality of the reconstructed tomographic images compared with conventional techniques, with the measured characteristics being in good agreement with the corresponding theoretical estimations. This improvement also corresponds to an approximately 400-fold reduction in the x-ray dose, compared with conventional absorption-based tomography, without a loss in the imaging quality. The results of this study confirm and quantify the significant potential benefits achievable in three-dimensional mammography using x-ray phase-contrast imaging and phase-retrieval techniques. (paper)

A study of intraluminal flow in patients with aortic disease by cine magnetic resonance imaging

International Nuclear Information System (INIS)

Ohnishi, Shusaku; Fukui, Sugao; Kusuoka, Hideo; Kitabatake, Akira; Kamada, Takenobu.

1990-01-01

To evaluate the usefulness of cine magnetic resonance (MR) imaging in the diagnosis of aortic disease, we applied cine MR sequences with conventional spin echo (SE) sequence to 15 patients with aortic aneurysm and 5 patients with aortic dissection. ECG gated multi slice SE images (single echo) were obtained in transverse plane and the planes along the long axis of aorta. TE of SE sequence ranged from 15 to 32 msec. Cine MR images were obtained in 17 frames, where TR ranged from 30 to 60 msec and TE from 10 to 22 msec. We got these results as follows. For aortic aneurysm, SE images showed aneurysmal dilatation in thoracic aorta in 9 cases, and in abdominal aorta in 6 cases. Cine MR images showed us the intraluminal flow with high signal intensity. We could differentiate the slow flow image from mural thrombus using SE and cine MR sequences in the same plane. We could evaluate the dynamic flow image within a cavity of aneurysm and in in-flow and out-flow portions of aorta by cine MR imaging. For aortic dissection, SE images delineated the intimal tear and two separated lumens in all cases. We could obtain flow images within true and false lumen by cine MR imaging. The signal intensity within true lumen was higher than that within false lumen. It seemed to be due to the difference of flow velocity and the turbulence within false lumen. Entry to false lumen was seen as the interruption of dissected intima on SE images. Cine MR images clearly depicted the blood flow communication between two lumens through the entry. In 3 of 5 cases the blood flow through the entry was seen in both directions, from true to false lumen in systole and inversely in diastole. Thus, cine MR imaging will add the useful hemodynamic information in the diagnosis of aortic disease by conventional MR imaging. (author)

Visualizing Typical Features of Breast Fibroadenomas Using Phase-Contrast CT: An Ex-Vivo Study

Science.gov (United States)

Grandl, Susanne; Willner, Marian; Herzen, Julia; Sztrókay-Gaul, Anikó; Mayr, Doris; Auweter, Sigrid D.; Hipp, Alexander; Birnbacher, Lorenz; Marschner, Mathias; Chabior, Michael; Reiser, Maximilian; Pfeiffer, Franz; Bamberg, Fabian; Hellerhoff, Karin

2014-01-01

Background Fibroadenoma is the most common benign solid breast lesion type and a very common cause for histologic assessment. To justify a conservative therapy, a highly specific discrimination between fibroadenomas and other breast lesions is crucial. Phase-contrast imaging offers improved soft-tissue contrast and differentiability of fine structures combined with the potential of 3-dimensional imaging. In this study we assessed the potential of grating-based phase-contrast CT imaging for visualizing diagnostically relevant features of fibroadenomas. Materials and Methods Grating-based phase-contrast CT was performed on six ex-vivo formalin-fixed breast specimens containing a fibroadenoma and three samples containing benign changes that resemble fibroadenomas using Talbot Lau interferometry and a polychromatic X-ray source. Phase-contrast and simultaneously acquired absorption-based 3D-datasets were manually matched with corresponding histological slices. The visibility of diagnostically valuable features was assessed in comparison with histology as the gold-standard. Results In all cases, matching of grating-based phase-contrast CT images and histology was successfully completed. Grating-based phase-contrast CT showed greatly improved differentiation of fine structures and provided accurate depiction of strands of fibrous tissue within the fibroadenomas as well as of the diagnostically valuable dilated, branched ductuli of the fibroadenomas. A clear demarcation of tumor boundaries in all cases was provided by phase- but not absorption-contrast CT. Conclusions Pending successful translation of the technology to a clinical setting and considerable reduction of the required dose, the data presented here suggest that grating-based phase-contrast CT may be used as a supplementary non-invasive diagnostic tool in breast diagnostics. Phase-contrast CT may thus contribute to the reduction of false positive findings and reduce the recall and core biopsy rate in population

Accelerated high-frame-rate mouse heart cine-MRI using compressed sensing reconstruction.

Science.gov (United States)

Motaal, Abdallah G; Coolen, Bram F; Abdurrachim, Desiree; Castro, Rui M; Prompers, Jeanine J; Florack, Luc M J; Nicolay, Klaas; Strijkers, Gustav J

2013-04-01

We introduce a new protocol to obtain very high-frame-rate cinematographic (Cine) MRI movies of the beating mouse heart within a reasonable measurement time. The method is based on a self-gated accelerated fast low-angle shot (FLASH) acquisition and compressed sensing reconstruction. Key to our approach is that we exploit the stochastic nature of the retrospective triggering acquisition scheme to produce an undersampled and random k-t space filling that allows for compressed sensing reconstruction and acceleration. As a standard, a self-gated FLASH sequence with a total acquisition time of 10 min was used to produce single-slice Cine movies of seven mouse hearts with 90 frames per cardiac cycle. Two times (2×) and three times (3×) k-t space undersampled Cine movies were produced from 2.5- and 1.5-min data acquisitions, respectively. The accelerated 90-frame Cine movies of mouse hearts were successfully reconstructed with a compressed sensing algorithm. The movies had high image quality and the undersampling artifacts were effectively removed. Left ventricular functional parameters, i.e. end-systolic and end-diastolic lumen surface areas and early-to-late filling rate ratio as a parameter to evaluate diastolic function, derived from the standard and accelerated Cine movies, were nearly identical. Copyright © 2012 John Wiley & Sons, Ltd.

Combined fluorescence and phase contrast imaging at the Advanced Photon Source

International Nuclear Information System (INIS)

Hornberger, B.; Feser, M.; Jacobsen, C.; Vogt, S.; Legnini, D.; Paterson, D.; Rehak, P.; DeGeronimo, G.; Palmer, B.M.; Experimental Facilities Division; State Univ. of New York at Stony Brook Univ.; BNL; Univ. of Vermont

2006-01-01

X-ray fluorescence microprobes excel at detecting and quantifying trace metals in biological and environmental science samples, but typically do not detect low Z elements such as carbon and nitrogen. Therefore, it is hard to put the trace metals into context with their natural environment. We are implementing phase contrast capabilities with a segmented detector into several microprobes at the Advanced Photon Source (APS) to address this problem. Qualitative differential phase contrast images from a modified soft x-ray detector already provide very useful information for general users. We are also implementing a quantitative method to recover the absolute phase shift by Fourier filtering detector images. New detectors are under development which are optimized for the signal levels present at the APS. In this paper, we concentrate on fundamental signal to noise considerations comparing absorption and differential phase contrast

Phase shift extraction and wavefront retrieval from interferograms with background and contrast fluctuations

International Nuclear Information System (INIS)

Liu, Qian; Wang, Yang; He, Jianguo; Ji, Fang

2015-01-01

The fluctuations of background and contrast cause measurement errors in the phase-shifting technique. To extract the phase shifts from interferograms with background and contrast fluctuations, an iterative algorithm is represented. The phase shifts and wavefront phase are calculated in two individual steps with the least-squares method. The fluctuation factors are determined when the phase shifts are calculated, and the fluctuations are compensated when the wavefront phase is calculated. The advantage of the algorithm lies in its ability to extract phase shifts from interferograms with background and contrast fluctuations converging stably and rapidly. Simulations and experiments verify the effectiveness and reliability of the proposed algorithm. The convergence accuracy and speed are demonstrated by the simulation results. The experiment results show its ability for suppressing phase retrieval errors. (paper)

In-line X-ray phase-contrast imaging of murine liver microvasculature ex vivo

International Nuclear Information System (INIS)

Li Beilei; Xu Min; Shi Hongcheng; Chen Shaoliang; Wu Weizhong; Peng Guanyun; Zhang Xi; Peng Yifeng

2012-01-01

Imaging blood vessels is of importance for determining the vascular distribution of organs and tumors. Phase-contrast X-ray imaging can reveal the vessels in much more detail than conventional X-ray absorption method. Visualizing murine liver microvasculature ex vivo with phase-contrast X-ray imaging was performed at Shanghai Synchrotron Radiation Facility. Barium sulfate and physiological saline were used as contrast agents for the blood vessels. Blood vessels of <Φ20 μm could be detected by replacing resident blood with physiological saline or barium sulfate. An entire branch of the portal vein (from the main axial portal vein to the ninth generation of branching) could be captured in a single phase-contrast image. It is demonstrated that selective angiography based on phase contrast X-ray imaging, with a physiological material of low Z elements (such as saline) being the contrast agent, is a viable imaging strategy. Further efforts will be focused on using the technique to image tumor angiogenesis. (authors)

SU-E-J-238: First-Order Approximation of Time-Resolved 4DMRI From Cine 2DMRI and Respiratory-Correlated 4DMRI

International Nuclear Information System (INIS)

Li, G; Tyagi, N; Deasy, J; Wei, J; Hunt, M

2015-01-01

Purpose: Cine 2DMRI is useful in MR-guided radiotherapy but it lacks volumetric information. We explore the feasibility of estimating timeresolved (TR) 4DMRI based on cine 2DMRI and respiratory-correlated (RC) 4DMRI though simulation. Methods: We hypothesize that a volumetric image during free breathing can be approximated by interpolation among 3DMRI image sets generated from a RC-4DMRI. Two patients’ RC-4DMRI with 4 or 5 phases were used to generate additional 3DMRI by interpolation. For each patient, six libraries were created to have total 5-to-35 3DMRI images by 0–6 equi-spaced tri-linear interpolation between adjacent and full-inhalation/full-exhalation phases. Sagittal cine 2DMRI were generated from reference 3DMRIs created from separate, unique interpolations from the original RC-4DMRI. To test if accurate 3DMRI could be generated through rigid registration of the cine 2DMRI to the 3DMRI libraries, each sagittal 2DMRI was registered to sagittal cuts in the same location in the 3DMRI within each library to identify the two best matches: one with greater lung volume and one with smaller. A final interpolation between the corresponding 3DMRI was then performed to produce the first-order-approximation (FOA) 3DMRI. The quality and performance of the FOA as a function of library size was assessed using both the difference in lung volume and average voxel intensity between the FOA and the reference 3DMRI. Results: The discrepancy between the FOA and reference 3DMRI decreases as the library size increases. The 3D lung volume difference decreases from 5–15% to 1–2% as the library size increases from 5 to 35 image sets. The average difference in lung voxel intensity decreases from 7–8 to 5–6 with the lung intensity being 0–135. Conclusion: This study indicates that the quality of FOA 3DMRI improves with increasing 3DMRI library size. On-going investigations will test this approach using actual cine 2DMRI and introduce a higher order approximation for

Assessment of small bowel motility in patients with chronic intestinal pseudo-obstruction using cine-MRI.

Science.gov (United States)

Ohkubo, Hidenori; Kessoku, Takaomi; Fuyuki, Akiko; Iida, Hiroshi; Inamori, Masahiko; Fujii, Tetsuro; Kawamura, Harunobu; Hata, Yasuo; Manabe, Noriaki; Chiba, Toshimi; Kwee, Thomas C; Haruma, Ken; Matsuhashi, Nobuyuki; Nakajima, Atsushi; Takahara, Taro

2013-07-01

Chronic intestinal pseudo-obstruction (CIPO) is a rare, serious motility disorder, with life-threatening complications over time. However, lack of an established, non-invasive diagnostic method has caused delays in the diagnosis of this intractable disease. Cine-magnetic resonance imaging (MRI) is an emerging technique, with a potential to evaluate the motility of the entire bowel. We compared small bowel motility in healthy volunteers, patients with irritable bowel syndrome (IBS), and those with CIPO, using cine-MRI, and evaluated the usefulness of cine-MRI as a novel diagnostic method for CIPO. Twelve healthy volunteers, IBS patients, and CIPO patients prospectively underwent cine-MRI at 1.5 T. Luminal diameter, contraction ratio, and contraction cycle were measured and compared between the groups. Cine-MRI provided sufficient dynamic images to assess the motility of the entire small bowel. Luminal diameter (mean±s.d.) in CIPO patients was significantly higher than that in healthy volunteers and IBS patients (43.4±14.1, 11.1±1.5, and 10.9±1.9 mm, respectively), and contraction ratio was significantly lower in CIPO patients than that in healthy volunteers and IBS patients (17.1±11.0%, 73.0±9.3%, and 74.6±9.4%, respectively). No significant differences were observed in the contraction cycle. This study is the first to assess the clinical utility of cine-MRI in CIPO patients. Cine-MRI clearly detected contractility impairments in CIPO patients. Cine-MRI is noninvasive, radiation-free, and can directly evaluate the entire small bowel peristalsis, and can detect the affected loops at a glance; therefore, it might be extremely useful for the diagnosis and follow-up of CIPO patients in clinical practice.

TH-EF-BRA-08: A Novel Technique for Estimating Volumetric Cine MRI (VC-MRI) From Multi-Slice Sparsely Sampled Cine Images Using Motion Modeling and Free Form Deformation

International Nuclear Information System (INIS)

Harris, W; Yin, F; Wang, C; Chang, Z; Cai, J; Zhang, Y; Ren, L

2016-01-01

Purpose: To develop a technique to estimate on-board VC-MRI using multi-slice sparsely-sampled cine images, patient prior 4D-MRI, motion-modeling and free-form deformation for real-time 3D target verification of lung radiotherapy. Methods: A previous method has been developed to generate on-board VC-MRI by deforming prior MRI images based on a motion model(MM) extracted from prior 4D-MRI and a single-slice on-board 2D-cine image. In this study, free-form deformation(FD) was introduced to correct for errors in the MM when large anatomical changes exist. Multiple-slice sparsely-sampled on-board 2D-cine images located within the target are used to improve both the estimation accuracy and temporal resolution of VC-MRI. The on-board 2D-cine MRIs are acquired at 20–30frames/s by sampling only 10% of the k-space on Cartesian grid, with 85% of that taken at the central k-space. The method was evaluated using XCAT(computerized patient model) simulation of lung cancer patients with various anatomical and respirational changes from prior 4D-MRI to onboard volume. The accuracy was evaluated using Volume-Percent-Difference(VPD) and Center-of-Mass-Shift(COMS) of the estimated tumor volume. Effects of region-of-interest(ROI) selection, 2D-cine slice orientation, slice number and slice location on the estimation accuracy were evaluated. Results: VCMRI estimated using 10 sparsely-sampled sagittal 2D-cine MRIs achieved VPD/COMS of 9.07±3.54%/0.45±0.53mm among all scenarios based on estimation with ROI_MM-ROI_FD. The FD optimization improved estimation significantly for scenarios with anatomical changes. Using ROI-FD achieved better estimation than global-FD. Changing the multi-slice orientation to axial, coronal, and axial/sagittal orthogonal reduced the accuracy of VCMRI to VPD/COMS of 19.47±15.74%/1.57±2.54mm, 20.70±9.97%/2.34±0.92mm, and 16.02±13.79%/0.60±0.82mm, respectively. Reducing the number of cines to 8 enhanced temporal resolution of VC-MRI by 25% while

TH-EF-BRA-08: A Novel Technique for Estimating Volumetric Cine MRI (VC-MRI) From Multi-Slice Sparsely Sampled Cine Images Using Motion Modeling and Free Form Deformation

Energy Technology Data Exchange (ETDEWEB)

Harris, W; Yin, F; Wang, C; Chang, Z; Cai, J; Zhang, Y; Ren, L [Duke University Medical Center, Durham, NC (United States)

2016-06-15

Purpose: To develop a technique to estimate on-board VC-MRI using multi-slice sparsely-sampled cine images, patient prior 4D-MRI, motion-modeling and free-form deformation for real-time 3D target verification of lung radiotherapy. Methods: A previous method has been developed to generate on-board VC-MRI by deforming prior MRI images based on a motion model(MM) extracted from prior 4D-MRI and a single-slice on-board 2D-cine image. In this study, free-form deformation(FD) was introduced to correct for errors in the MM when large anatomical changes exist. Multiple-slice sparsely-sampled on-board 2D-cine images located within the target are used to improve both the estimation accuracy and temporal resolution of VC-MRI. The on-board 2D-cine MRIs are acquired at 20–30frames/s by sampling only 10% of the k-space on Cartesian grid, with 85% of that taken at the central k-space. The method was evaluated using XCAT(computerized patient model) simulation of lung cancer patients with various anatomical and respirational changes from prior 4D-MRI to onboard volume. The accuracy was evaluated using Volume-Percent-Difference(VPD) and Center-of-Mass-Shift(COMS) of the estimated tumor volume. Effects of region-of-interest(ROI) selection, 2D-cine slice orientation, slice number and slice location on the estimation accuracy were evaluated. Results: VCMRI estimated using 10 sparsely-sampled sagittal 2D-cine MRIs achieved VPD/COMS of 9.07±3.54%/0.45±0.53mm among all scenarios based on estimation with ROI-MM-ROI-FD. The FD optimization improved estimation significantly for scenarios with anatomical changes. Using ROI-FD achieved better estimation than global-FD. Changing the multi-slice orientation to axial, coronal, and axial/sagittal orthogonal reduced the accuracy of VCMRI to VPD/COMS of 19.47±15.74%/1.57±2.54mm, 20.70±9.97%/2.34±0.92mm, and 16.02±13.79%/0.60±0.82mm, respectively. Reducing the number of cines to 8 enhanced temporal resolution of VC-MRI by 25% while

Ex vivo characterization of pathologic fluids with quantitative phase-contrast computed tomography

Energy Technology Data Exchange (ETDEWEB)

Richter, Vivien, E-mail: vivien.richter@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, Eberhard Karls Universität Tübingen, Hoppe-Seyler-Weg 3, 72076 Tuebingen (Germany); Willner, Marian S., E-mail: marian.willner@ph.tum.de [Department of Physics & Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching (Germany); Henningsen, John, E-mail: john.henningsen@tum.de [Department of Physics & Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching (Germany); Birnbacher, Lorenz, E-mail: lorenz.birnbacher@ph.tum.de [Department of Physics & Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching (Germany); Marschner, Mathias, E-mail: mathias.marschner@ph.tum.de [Department of Physics & Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching (Germany); Herzen, Julia, E-mail: julia.herzen@ph.tum.de [Department of Physics & Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching (Germany); Kimm, Melanie A., E-mail: melanie.kimm@tum.de [Department of Diagnostic and Interventional Radiology, Technische Universität München, Ismaninger Str. 22, 81675 Munich (Germany); and others

2017-01-15

Purpose: X-ray phase-contrast imaging (PCI) provides additional information beyond absorption characteristics by detecting the phase shift of the X-ray beam passing through material. The grating-based system works with standard polychromatic X-ray sources, promising a possible clinical implementation. PCI has been shown to provide additional information in soft-tissue samples. The aim of this study was to determine if ex vivo quantitative phase-contrast computed tomography (PCCT) may differentiate between pathologic fluid collections. Materials and methods: PCCT was performed with the grating interferometry method. A protein serial dilution, human blood samples and 17 clinical samples of pathologic fluid retentions were imaged and correlated with clinical chemistry measurements. Conventional and phase-contrast tomography images were reconstructed. Phase-contrast Hounsfield Units (HUp) were used for quantitative analysis analogously to conventional HU. The imaging was analyzed using overall means, ROI values as well as whole-volume-histograms and vertical gradients. Contrast to noise ratios were calculated between different probes and between imaging methods. Results: HUp showed a very good linear correlation with protein concentration in vitro. In clinical samples, HUp correlated rather well with cell count and triglyceride content. PCI was better than absorption imaging at differentiating protein concentrations in the protein samples as well as at differentiating blood plasma from cellular components. PCI also allowed for differentiation of watery samples (such as lymphoceles) from pus. Conclusion: Phase-contrast computed tomography is a promising tool for the differentiation of pathologic fluids that appear homogenous with conventional attenuation imaging.

Recent advances in synchrotron-based hard x-ray phase contrast imaging

International Nuclear Information System (INIS)

Liu, Y; Nelson, J; Andrews, J C; Pianetta, P; Holzner, C

2013-01-01

Ever since the first demonstration of phase contrast imaging (PCI) in the 1930s by Frits Zernike, people have realized the significant advantage of phase contrast over conventional absorption-based imaging in terms of sensitivity to ‘transparent’ features within specimens. Thus, x-ray phase contrast imaging (XPCI) holds great potential in studies of soft biological tissues, typically containing low Z elements such as C, H, O and N. Particularly when synchrotron hard x-rays are employed, the favourable brightness, energy tunability, monochromatic characteristics and penetration depth have dramatically enhanced the quality and variety of XPCI methods, which permit detection of the phase shift associated with 3D geometry of relatively large samples in a non-destructive manner. In this paper, we review recent advances in several synchrotron-based hard x-ray XPCI methods. Challenges and key factors in methodological development are discussed, and biological and medical applications are presented. (paper)

Recent advances in synchrotron-based hard x-ray phase contrast imaging

Science.gov (United States)

Liu, Y.; Nelson, J.; Holzner, C.; Andrews, J. C.; Pianetta, P.

2013-12-01

Ever since the first demonstration of phase contrast imaging (PCI) in the 1930s by Frits Zernike, people have realized the significant advantage of phase contrast over conventional absorption-based imaging in terms of sensitivity to ‘transparent’ features within specimens. Thus, x-ray phase contrast imaging (XPCI) holds great potential in studies of soft biological tissues, typically containing low Z elements such as C, H, O and N. Particularly when synchrotron hard x-rays are employed, the favourable brightness, energy tunability, monochromatic characteristics and penetration depth have dramatically enhanced the quality and variety of XPCI methods, which permit detection of the phase shift associated with 3D geometry of relatively large samples in a non-destructive manner. In this paper, we review recent advances in several synchrotron-based hard x-ray XPCI methods. Challenges and key factors in methodological development are discussed, and biological and medical applications are presented.

Comparison of standard, prone and cine MRI in the evaluation of tethered cord

International Nuclear Information System (INIS)

Singh, Sukhjinder; Kline-Fath, Beth; Racadio, Judy M.; Bierbrauer, Karin; Salisbury, Shelia; Macaluso, Maurizio; Jackson, Elizabeth C.; Egelhoff, John C.

2012-01-01

Tethered cord syndrome (TCS) is defined by abnormal traction on the spinal cord that confines its movement. Surgical cord release usually stops neurological deterioration; therefore, early and accurate neuroradiological diagnosis is important. Supine MRI is the imaging modality of choice, but prone MRI and cine MRI can demonstrate cord movement. We compared the diagnostic accuracies of standard MRI, prone MRI and cine MRI in patients with clinical suspicion of TCS and evaluated inter-reader reliability for MR imaging. Children who underwent MRI for suspicion of TCS were retrospectively identified. Supine, prone and cine MRI studies were re-read by two pediatric neuroradiologists. Conus level, filum appearance and cord movement were documented. Thirteen of 49 children had tethered cord documented at surgery. Conus level had the highest diagnostic accuracy (sensitivity 69-77%, specificity 94%, positive predictive value 82-83%, negative predictive value 89-92%, correct diagnosis 88-90%) and highest between-reader concordance (98%). Prone and cine MRI did not add to the accuracy of the supine imaging. Conus level provides the highest diagnostic accuracy and inter-reader reliability in TCS. Until a larger series is evaluated, it remains questionable whether prone or cine MRI provides enough additional diagnostic information to warrant routine use. (orig.)

Comparison of standard, prone and cine MRI in the evaluation of tethered cord

Energy Technology Data Exchange (ETDEWEB)

Singh, Sukhjinder [Cohen Children' s Medical Center, Department of Radiology, New Hyde Park, NY (United States); Kline-Fath, Beth; Racadio, Judy M. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Bierbrauer, Karin [Cincinnati Children' s Hospital Medical Center, Department of Neurosurgery, Cincinnati, OH (United States); Salisbury, Shelia; Macaluso, Maurizio [Cincinnati Children' s Hospital Medical Center, Division of Biostatistics and Epidemiology, Cincinnati, OH (United States); Jackson, Elizabeth C. [Cincinnati Children' s Hospital Medical Center, Department of Pediatrics, Division of Nephrology, Cincinnati, OH (United States); Egelhoff, John C. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Phoenix Children' s Hospital, Department of Radiology, Phoenix, AZ (United States)

2012-06-15

Tethered cord syndrome (TCS) is defined by abnormal traction on the spinal cord that confines its movement. Surgical cord release usually stops neurological deterioration; therefore, early and accurate neuroradiological diagnosis is important. Supine MRI is the imaging modality of choice, but prone MRI and cine MRI can demonstrate cord movement. We compared the diagnostic accuracies of standard MRI, prone MRI and cine MRI in patients with clinical suspicion of TCS and evaluated inter-reader reliability for MR imaging. Children who underwent MRI for suspicion of TCS were retrospectively identified. Supine, prone and cine MRI studies were re-read by two pediatric neuroradiologists. Conus level, filum appearance and cord movement were documented. Thirteen of 49 children had tethered cord documented at surgery. Conus level had the highest diagnostic accuracy (sensitivity 69-77%, specificity 94%, positive predictive value 82-83%, negative predictive value 89-92%, correct diagnosis 88-90%) and highest between-reader concordance (98%). Prone and cine MRI did not add to the accuracy of the supine imaging. Conus level provides the highest diagnostic accuracy and inter-reader reliability in TCS. Until a larger series is evaluated, it remains questionable whether prone or cine MRI provides enough additional diagnostic information to warrant routine use. (orig.)

Diagnosis of tracheal instability: inspiratory and expiratory spiral CT and cine CT

International Nuclear Information System (INIS)

Heussel, C.P.; Thelen, M.; Kauczor, H.U.; Hafner, B.; Lill, J.

2000-01-01

Purpose: In tracheo- and bronchomalacia, localization and determination of collapse is necessary for planning a surgical procedure. We compared inspiratory and spiral CT, cine CT, and bronchoscopy and evaluated the relevance of each method. Methods: Seventeen patients with suspected or verified tracheal stonosis or collapse underwent paired inspiratory and exspiratory spiral CT and cine CT during continuous respiration (temporal increment 100 ms). The tracheal cross-sectional area was calculated and compared. Results: In addition to bronchoscopy, further information concerning localization, extent, collapse, stability of the tracheal wall, distal portions of the stenosis, and extraluminal compressions was obtained. A significantly higher degree of tracheal collapse was seen using cine CT compared to paired spiral CT (p [de

El cine mexicano de la edad de oro y su impacto internacional

Directory of Open Access Journals (Sweden)

Maricruz Castro-Ricalde

2014-06-01

Full Text Available A partir de una investigación documental en publicaciones periódicas de Argentina, Colombia, Cuba, Chile, Estados Unidos, Honduras, México, Nicaragua y Venezuela, este artículo demuestra el interés que el cine mexicano producido entre 1936 y 1956 provocó en los espectadores de Hispanoamérica y Estados Unidos, al igual que la presencia de actores, cineastas, temas y personajes de otros países hispanohablantes en la industria cinematográfica mexicana durante la denominada edad de oro del cine mexicano. Se constató la influencia de este cine en la conformación de la identidad cultural de los mexicanos y su proyección internacional.

Phase contrast imaging using a micro focus x-ray source

Science.gov (United States)

Zhou, Wei; Majidi, Keivan; Brankov, Jovan G.

2014-09-01

Phase contrast x-ray imaging, a new technique to increase the imaging contrast for the tissues with close attenuation coefficients, has been studied since mid 1990s. This technique reveals the possibility to show the clear details of the soft tissues and tumors in small scale resolution. A compact and low cost phase contrast imaging system using a conventional x-ray source is described in this paper. Using the conventional x-ray source is of great importance, because it provides the possibility to use the method in hospitals and clinical offices. Simple materials and components are used in the setup to keep the cost in a reasonable and affordable range.Tungsten Kα1 line with the photon energy 59.3 keV was used for imaging. Some of the system design details are discussed. The method that was used to stabilize the system is introduced. A chicken thigh bone tissue sample was used for imaging followed by the image quality, image acquisition time and the potential clinical application discussion. High energy x-ray beam can be used in phase contrast imaging. Therefore the radiation dose to the patients can be greatly decreased compared to the traditional x-ray radiography.

SU-G-BRA-03: PCA Based Imaging Angle Optimization for 2D Cine MRI Based Radiotherapy Guidance

Energy Technology Data Exchange (ETDEWEB)

Chen, T; Yue, N; Jabbour, S; Zhang, M [Rutgers University, New Brunswick, NJ (United States)

2016-06-15

Purpose: To develop an imaging angle optimization methodology for orthogonal 2D cine MRI based radiotherapy guidance using Principal Component Analysis (PCA) of target motion retrieved from 4DCT. Methods: We retrospectively analyzed 4DCT of 6 patients with lung tumor. A radiation oncologist manually contoured the target volume at the maximal inhalation phase of the respiratory cycle. An object constrained deformable image registration (DIR) method has been developed to track the target motion along the respiration at ten phases. The motion of the center of the target mass has been analyzed using the PCA to find out the principal motion components that were uncorrelated with each other. Two orthogonal image planes for cineMRI have been determined using this method to minimize the through plane motion during MRI based radiotherapy guidance. Results: 3D target respiratory motion for all 6 patients has been efficiently retrieved from 4DCT. In this process, the object constrained DIR demonstrated satisfactory accuracy and efficiency to enable the automatic motion tracking for clinical application. The average motion amplitude in the AP, lateral, and longitudinal directions were 3.6mm (min: 1.6mm, max: 5.6mm), 1.7mm (min: 0.6mm, max: 2.7mm), and 5.6mm (min: 1.8mm, max: 16.1mm), respectively. Based on PCA, the optimal orthogonal imaging planes were determined for cineMRI. The average angular difference between the PCA determined imaging planes and the traditional AP and lateral imaging planes were 47 and 31 degrees, respectively. After optimization, the average amplitude of through plane motion reduced from 3.6mm in AP images to 2.5mm (min:1.3mm, max:3.9mm); and from 1.7mm in lateral images to 0.6mm (min: 0.2mm, max:1.5mm), while the principal in plane motion amplitude increased from 5.6mm to 6.5mm (min: 2.8mm, max: 17mm). Conclusion: DIR and PCA can be used to optimize the orthogonal image planes of cineMRI to minimize the through plane motion during radiotherapy

SU-G-BRA-03: PCA Based Imaging Angle Optimization for 2D Cine MRI Based Radiotherapy Guidance

International Nuclear Information System (INIS)

Chen, T; Yue, N; Jabbour, S; Zhang, M

2016-01-01

Purpose: To develop an imaging angle optimization methodology for orthogonal 2D cine MRI based radiotherapy guidance using Principal Component Analysis (PCA) of target motion retrieved from 4DCT. Methods: We retrospectively analyzed 4DCT of 6 patients with lung tumor. A radiation oncologist manually contoured the target volume at the maximal inhalation phase of the respiratory cycle. An object constrained deformable image registration (DIR) method has been developed to track the target motion along the respiration at ten phases. The motion of the center of the target mass has been analyzed using the PCA to find out the principal motion components that were uncorrelated with each other. Two orthogonal image planes for cineMRI have been determined using this method to minimize the through plane motion during MRI based radiotherapy guidance. Results: 3D target respiratory motion for all 6 patients has been efficiently retrieved from 4DCT. In this process, the object constrained DIR demonstrated satisfactory accuracy and efficiency to enable the automatic motion tracking for clinical application. The average motion amplitude in the AP, lateral, and longitudinal directions were 3.6mm (min: 1.6mm, max: 5.6mm), 1.7mm (min: 0.6mm, max: 2.7mm), and 5.6mm (min: 1.8mm, max: 16.1mm), respectively. Based on PCA, the optimal orthogonal imaging planes were determined for cineMRI. The average angular difference between the PCA determined imaging planes and the traditional AP and lateral imaging planes were 47 and 31 degrees, respectively. After optimization, the average amplitude of through plane motion reduced from 3.6mm in AP images to 2.5mm (min:1.3mm, max:3.9mm); and from 1.7mm in lateral images to 0.6mm (min: 0.2mm, max:1.5mm), while the principal in plane motion amplitude increased from 5.6mm to 6.5mm (min: 2.8mm, max: 17mm). Conclusion: DIR and PCA can be used to optimize the orthogonal image planes of cineMRI to minimize the through plane motion during radiotherapy

Alfonso Reyes y el cine del porvenir

Directory of Open Access Journals (Sweden)

Betina Keizman

2015-07-01

Full Text Available Este artículo se propone situar la reflexión de Alfonso Reyes sobre el cine en el marco de las recepciones del primer cine, considerando también cómo esta reflexión se articula en relación con el pensamiento crítico del escritor mexicano. En particular, se analiza el modo en que, por vía de la especulación, Reyes ensaya posibles redefiniciones para una nueva distribución de lo sensible y de las artes, de los valores cognitivos y expresivos de la luz y de los vínculos arte-ciencia. Lo que se lee en Reyes es un esfuerzo por pensar nuevas formas de inventiva que se desprenden (o podrían desprenderse del arte cinematográfico.

Imaging of metastatic lymph nodes by X-ray phase-contrast micro-tomography.

Directory of Open Access Journals (Sweden)

Torben Haugaard Jensen

Full Text Available Invasive cancer causes a change in density in the affected tissue, which can be visualized by x-ray phase-contrast tomography. However, the diagnostic value of this method has so far not been investigated in detail. Therefore, the purpose of this study was, in a blinded manner, to investigate whether malignancy could be revealed by non-invasive x-ray phase-contrast tomography in lymph nodes from breast cancer patients. Seventeen formalin-fixed paraffin-embedded lymph nodes from 10 female patients (age range 37-83 years diagnosed with invasive ductal carcinomas were analyzed by X-ray phase-contrast tomography. Ten lymph nodes had metastatic deposits and 7 were benign. The phase-contrast images were analyzed according to standards for conventional CT images looking for characteristics usually only visible by pathological examinations. Histopathology was used as reference. The result of this study was that the diagnostic sensitivity of the image analysis for detecting malignancy was 100% and the specificity was 87%. The positive predictive value was 91% for detecting malignancy and the negative predictive value was 100%. We conclude that x-ray phase-contrast imaging can accurately detect density variations to obtain information regarding lymph node involvement previously inaccessible with standard absorption x-ray imaging.

PHASE QUANTIZATION STUDY OF SPATIAL LIGHT MODULATOR FOR EXTREME HIGH-CONTRAST IMAGING

Energy Technology Data Exchange (ETDEWEB)

Dou, Jiangpei; Ren, Deqing, E-mail: jpdou@niaot.ac.cn, E-mail: jiangpeidou@gmail.com [Physics and Astronomy Department, California State University Northridge, 18111 Nordhoff Street, Northridge, CA 91330 (United States)

2016-11-20

Direct imaging of exoplanets by reflected starlight is extremely challenging due to the large luminosity ratio to the primary star. Wave-front control is a critical technique to attenuate the speckle noise in order to achieve an extremely high contrast. We present a phase quantization study of a spatial light modulator (SLM) for wave-front control to meet the contrast requirement of detection of a terrestrial planet in the habitable zone of a solar-type star. We perform the numerical simulation by employing the SLM with different phase accuracy and actuator numbers, which are related to the achievable contrast. We use an optimization algorithm to solve the quantization problems that is matched to the controllable phase step of the SLM. Two optical configurations are discussed with the SLM located before and after the coronagraph focal plane mask. The simulation result has constrained the specification for SLM phase accuracy in the above two optical configurations, which gives us a phase accuracy of 0.4/1000 and 1/1000 waves to achieve a contrast of 10{sup -10}. Finally, we have demonstrated that an SLM with more actuators can deliver a competitive contrast performance on the order of 10{sup -10} in comparison to that by using a deformable mirror.

Noninvasive 3D Structural Analysis of Arthropod by Synchrotron X-Ray Phase Contrast Tomography

International Nuclear Information System (INIS)

Yao, S.; Zong, Y.; Fan, J.; Sun, Z.; Jiang, H.

2015-01-01

X-ray imaging techniques significantly advanced our understanding of materials and biology, among which phase contrast X-ray microscopy has obvious advantages in imaging biological specimens which have low contrast by conventional absorption contrast microscopy. In this paper, three-dimensional microstructure of arthropod with high contrast has been demonstrated by synchrotron X-ray in-line phase contrast tomography. The external morphology and internal structures of an earthworm were analyzed based upon tomographic reconstructions with and without phase retrieval. We also identified and characterized various fine structural details such as the musculature system, the digestive system, the nervous system, and the circulatory system. This work exhibited the high efficiency, high precision, and wide potential applications of synchrotron X-ray phase contrast tomography in nondestructive investigation of low-density materials and biology.

High frame rate retrospectively triggered Cine MRI for assessment of murine diastolic function

NARCIS (Netherlands)

Coolen, Bram F.; Abdurrachim, Desiree; Motaal, Abdallah G.; Nicolay, Klaas; Prompers, Jeanine J.; Strijkers, Gustav J.

2013-01-01

To assess left ventricular (LV) diastolic function in mice with Cine MRI, a high frame rate (>60 frames per cardiac cycle) is required. For conventional electrocardiography-triggered Cine MRI, the frame rate is inversely proportional to the pulse repetition time (TR). However, TR cannot be lowered

Myocardial strain assessment by cine cardiac magnetic resonance imaging using non-rigid registration.

Science.gov (United States)

Tsadok, Yossi; Friedman, Zvi; Haluska, Brian A; Hoffmann, Rainer; Adam, Dan

2016-05-01

To evaluate a novel post-processing method for assessment of longitudinal mid-myocardial strain in standard cine cardiac magnetic resonance (CMR) imaging sequences. Cine CMR imaging and tagged cardiac magnetic resonance imaging (TMRI) were performed in 15 patients with acute myocardial infarction (AMI) and 15 healthy volunteers served as control group. A second group of 37 post-AMI patients underwent both cine CMR and late gadolinium enhancement (LGE) CMR exams. Speckle tracking echocardiography (STE) was performed in 36 of these patients. Cine CMR, TMRI and STE were analyzed to obtain longitudinal strain. LGE-CMR datasets were analyzed to evaluate scar extent. Comparison of peak systolic strain (PSS) measured from CMR and TMRI yielded a strong correlation (r=0.86, pcine CMR data. The method was found to be highly correlated with strain measurements obtained by TMRI and STE. This tool allows accurate discrimination between different transmurality states of myocardial infarction. Copyright © 2015 Elsevier Inc. All rights reserved.

Applications of phase-contrast x-ray imaging to medicine using an x-ray interferometer

Science.gov (United States)

Momose, Atsushi; Yoneyama, Akio; Takeda, Tohoru; Itai, Yuji; Tu, Jinhong; Hirano, Keiichi

1999-10-01

We are investigating possible medical applications of phase- contrast X-ray imaging using an X-ray interferometer. This paper introduces the strategy of the research project and the present status. The main subject is to broaden the observation area to enable in vivo observation. For this purpose, large X-ray interferometers were developed, and 2.5 cm X 1.5 cm interference patterns were generated using synchrotron X-rays. An improvement of the spatial resolution is also included in the project, and an X-ray interferometer designed for high-resolution phase-contrast X-ray imaging was fabricated and tested. In parallel with the instrumental developments, various soft tissues are observed by phase- contrast X-ray CT to find correspondence between the generated contrast and our histological knowledge. The observation done so far suggests that cancerous tissues are differentiated from normal tissues and that blood can produce phase contrast. Furthermore, this project includes exploring materials that modulate phase contrast for selective imaging.

TH-A-BRF-04: Intra-Fraction Motion Characterization for Early Stage Rectal Cancer Using Cine-MRI

International Nuclear Information System (INIS)

Kleijnen, J; Asselen, B; Burbach, M; Intven, M; Reerink, O; Philippens, M; Lagendijk, J; Raaymakers, B

2014-01-01

Purpose: To investigate the intra-fraction motion in patients with early stage rectal cancer using cine-MRI. Methods: Sixteen patient diagnosed with early stage rectal cancer underwent 1.5 T MR imaging prior to each treatment fraction of their short course radiotherapy (n=76). During each scan session, three 2D sagittal cine-MRIs were performed: at the beginning (Start), after 9:30 minutes (Mid), and after 18 minutes (End). Each cine-MRI has a duration of one minute at 2Hz temporal resolution, resulting in a total of 3:48 hours of cine-MRI. Additionally, standard T2-weighted (T2w) imaging was performed. Clinical target volume (CTV) an tumor (GTV) were delineated on the T2w scan and transferred to the first time-point of each cine-MRI scan. Within each cine-MRI, the first frame was registered to the remaining frames of the scan, using a non-rigid B-spline registration. To investigate potential drifts, a similar registration was performed between the first frame of the Start and End scans.To evaluate the motion, the distances by which the edge pixels of the delineations move in anterior-posterior (AP) and cranial-caudal (CC) direction, were determined using the deformation field of the registrations. The distance which incorporated 95% of these edge pixels (dist95%) was determined within each cine-MRI, and between Start- End scans, respectively. Results: Within a cine-MRI, we observed an average dist95% for the CTV of 1.3mm/1.5mm (SD=0.7mm/0.6mm) and for the GTV of 1.2mm/1.5mm (SD=0.8mm/0.9mm), in respectively AP/CC. For the CTV motion between the Start and End scan, an average dist95% of 5.5mm/5.3mm (SD=3.1mm/2.5mm) was found, in respectively AP/CC. For the GTV motion, an average dist95% of 3.6mm/3.9mm (SD=2.2mm/2.5mm) was found in AP/CC, respectively. Conclusion: Although intra-fraction motion within a one minute cine-MRI is limited, substantial intra-fraction motion was observed within the 18 minute time period between the Start and End cine-MRI

Accelerated cardiac cine MRI using locally low rank and finite difference constraints.

Science.gov (United States)

Miao, Xin; Lingala, Sajan Goud; Guo, Yi; Jao, Terrence; Usman, Muhammad; Prieto, Claudia; Nayak, Krishna S

2016-07-01

To evaluate the potential value of combining multiple constraints for highly accelerated cardiac cine MRI. A locally low rank (LLR) constraint and a temporal finite difference (FD) constraint were combined to reconstruct cardiac cine data from highly undersampled measurements. Retrospectively undersampled 2D Cartesian reconstructions were quantitatively evaluated against fully-sampled data using normalized root mean square error, structural similarity index (SSIM) and high frequency error norm (HFEN). This method was also applied to 2D golden-angle radial real-time imaging to facilitate single breath-hold whole-heart cine (12 short-axis slices, 9-13s single breath hold). Reconstruction was compared against state-of-the-art constrained reconstruction methods: LLR, FD, and k-t SLR. At 10 to 60 spokes/frame, LLR+FD better preserved fine structures and depicted myocardial motion with reduced spatio-temporal blurring in comparison to existing methods. LLR yielded higher SSIM ranking than FD; FD had higher HFEN ranking than LLR. LLR+FD combined the complimentary advantages of the two, and ranked the highest in all metrics for all retrospective undersampled cases. Single breath-hold multi-slice cardiac cine with prospective undersampling was enabled with in-plane spatio-temporal resolutions of 2×2mm(2) and 40ms. Highly accelerated cardiac cine is enabled by the combination of 2D undersampling and the synergistic use of LLR and FD constraints. Copyright © 2016 Elsevier Inc. All rights reserved.

Accelerated two-dimensional cine DENSE cardiovascular magnetic resonance using compressed sensing and parallel imaging.

Science.gov (United States)

Chen, Xiao; Yang, Yang; Cai, Xiaoying; Auger, Daniel A; Meyer, Craig H; Salerno, Michael; Epstein, Frederick H

2016-06-14

Cine Displacement Encoding with Stimulated Echoes (DENSE) provides accurate quantitative imaging of cardiac mechanics with rapid displacement and strain analysis; however, image acquisition times are relatively long. Compressed sensing (CS) with parallel imaging (PI) can generally provide high-quality images recovered from data sampled below the Nyquist rate. The purposes of the present study were to develop CS-PI-accelerated acquisition and reconstruction methods for cine DENSE, to assess their accuracy for cardiac imaging using retrospective undersampling, and to demonstrate their feasibility for prospectively-accelerated 2D cine DENSE imaging in a single breathhold. An accelerated cine DENSE sequence with variable-density spiral k-space sampling and golden angle rotations through time was implemented. A CS method, Block LOw-rank Sparsity with Motion-guidance (BLOSM), was combined with sensitivity encoding (SENSE) for the reconstruction of under-sampled multi-coil spiral data. Seven healthy volunteers and 7 patients underwent 2D cine DENSE imaging with fully-sampled acquisitions (14-26 heartbeats in duration) and with prospectively rate-2 and rate-4 accelerated acquisitions (14 and 8 heartbeats in duration). Retrospectively- and prospectively-accelerated data were reconstructed using BLOSM-SENSE and SENSE. Image quality of retrospectively-undersampled data was quantified using the relative root mean square error (rRMSE). Myocardial displacement and circumferential strain were computed for functional assessment, and linear correlation and Bland-Altman analyses were used to compare accelerated acquisitions to fully-sampled reference datasets. For retrospectively-undersampled data, BLOSM-SENSE provided similar or lower rRMSE at rate-2 and lower rRMSE at rate-4 acceleration compared to SENSE (p cine DENSE provided good image quality and expected values of displacement and strain. BLOSM-SENSE-accelerated spiral cine DENSE imaging with 2D displacement encoding can be

Simulation of single grid-based phase-contrast x-ray imaging (g-PCXI)

Energy Technology Data Exchange (ETDEWEB)

Lim, H.W.; Lee, H.W. [Department of Radiation Convergence Engineering, iTOMO Group, Yonsei University, 1 Yonseidae-gil, Wonju, Gangwon-do 26493 (Korea, Republic of); Cho, H.S., E-mail: hscho1@yonsei.ac.kr [Department of Radiation Convergence Engineering, iTOMO Group, Yonsei University, 1 Yonseidae-gil, Wonju, Gangwon-do 26493 (Korea, Republic of); Je, U.K.; Park, C.K.; Kim, K.S.; Kim, G.A.; Park, S.Y.; Lee, D.Y.; Park, Y.O.; Woo, T.H. [Department of Radiation Convergence Engineering, iTOMO Group, Yonsei University, 1 Yonseidae-gil, Wonju, Gangwon-do 26493 (Korea, Republic of); Lee, S.H.; Chung, W.H.; Kim, J.W.; Kim, J.G. [R& D Center, JPI Healthcare Co., Ltd., Ansan 425-833 (Korea, Republic of)

2017-04-01

Single grid-based phase-contrast x-ray imaging (g-PCXI) technique, which was recently proposed by Wen et al. to retrieve absorption, scattering, and phase-gradient images from the raw image of the examined object, seems a practical method for phase-contrast imaging with great simplicity and minimal requirements on the setup alignment. In this work, we developed a useful simulation platform for g-PCXI and performed a simulation to demonstrate its viability. We also established a table-top setup for g-PCXI which consists of a focused-linear grid (200-lines/in strip density), an x-ray tube (100-μm focal spot size), and a flat-panel detector (48-μm pixel size) and performed a preliminary experiment with some samples to show the performance of the simulation platform. We successfully obtained phase-contrast x-ray images of much enhanced contrast from both the simulation and experiment and the simulated contract seemed similar to the experimental contrast, which shows the performance of the developed simulation platform. We expect that the simulation platform will be useful for designing an optimal g-PCXI system. - Highlights: • It is proposed for the single grid-based phase-contrast x-ray imaging (g-PCXI) technique. • We implemented for a numerical simulation code. • The preliminary experiment with several samples to compare is performed. • It is expected to be useful to design an optimal g-PCXI system.

PA/Lateral chest X-ray is equivalent to cine-fluoroscopy for the detection of conductor externalization in defibrillation leads.

Science.gov (United States)

Steinberg, Christian; Sarrazin, Jean-François; Philippon, François; Champagne, Jean; Molin, Franck; Nault, Isabelle; Blier, Louis; Bouchard, Marc-André; Arsenault, Jean; O'Hara, Gilles

2015-01-01

Riata™ and Riata ST defibrillation leads (St. Jude Medical, Sylmar, CA, USA) are susceptible to insulation defects with conductor externalization. Cine-fluoroscopy is considered to be the gold standard for the documentation of insulation defects, but similar detection rates have been reported for posterior-anterior (PA)/lateral chest x-ray (CXR) with zooming. Prospective single-center study to assess the diagnostic equivalence of a PA/lateral CXR with zooming for the detection of Riata insulation defects in a direct comparison to cine-fluoroscopy. Seventy-eight consecutive patients underwent 3-view cine-fluoroscopy and a PA/lateral CXR. All CXRs and cine-fluoroscopy images were reviewed by blinded electrophysiologists and staff radiologists. Forty-four of 78 patients had an abnormal cine-fluoroscopy (56%). The diagnostic correlation between PA/lateral CXR and cine-fluoroscopy was excellent (κ = 0.90; 95% confidence interval 0.80-1.00). PA/lateral CXR was equivalent to cine-fluoroscopy for the detection of conductor externalization showing a sensitivity of 97.7% and a specificity of 91.2%. The mean radiation effective dose of CXR was significantly lower compared to cine-fluoroscopy (0.09 millisievert [mSV] vs 0.85 ± 0.47 mSv; P cine-fluoroscopy for the detection of Riata insulation defects and should be considered as the preferred screening method. ©2014 Wiley Periodicals, Inc.

Cine CT: a new technology for cardiac computed tomography

International Nuclear Information System (INIS)

Boyd, D.P.; Peschmann, K.R.; Rand, R.E.; Napel, S.A.; Gould, R.; Farmer, D.W.; Lipton, M.J.; Higgins, C.B.; Couch, J.L.

1987-01-01

The technical requirements for adequate evaluation of cardiac anatomy and physiology, namely scan speeds in the 33-100 msec range, simultaneous multi-slice capability, 15-20 multi-level scans/second and a repeat multi-slice study at one per second, have been realized with the inception of the Cine-CT scanner. This scanner acquires scan data in 50 milliseconds by eliminating moving parts and using a scanning electron beam to produce a high speed X-ray source. The authors describe this scanner and the three scanning modes available: continuous or cine mode; flow or triggered mode; and full resolution mode. (Auth.)

Automatic segmentation of left ventricle in cardiac cine MRI images based on deep learning

Science.gov (United States)

Zhou, Tian; Icke, Ilknur; Dogdas, Belma; Parimal, Sarayu; Sampath, Smita; Forbes, Joseph; Bagchi, Ansuman; Chin, Chih-Liang; Chen, Antong

2017-02-01

In developing treatment of cardiovascular diseases, short axis cine MRI has been used as a standard technique for understanding the global structural and functional characteristics of the heart, e.g. ventricle dimensions, stroke volume and ejection fraction. To conduct an accurate assessment, heart structures need to be segmented from the cine MRI images with high precision, which could be a laborious task when performed manually. Herein a fully automatic framework is proposed for the segmentation of the left ventricle from the slices of short axis cine MRI scans of porcine subjects using a deep learning approach. For training the deep learning models, which generally requires a large set of data, a public database of human cine MRI scans is used. Experiments on the 3150 cine slices of 7 porcine subjects have shown that when comparing the automatic and manual segmentations the mean slice-wise Dice coefficient is about 0.930, the point-to-curve error is 1.07 mm, and the mean slice-wise Hausdorff distance is around 3.70 mm, which demonstrates the accuracy and robustness of the proposed inter-species translational approach.

Observation of human tissue with phase-contrast x-ray computed tomography

Science.gov (United States)

Momose, Atsushi; Takeda, Tohoru; Itai, Yuji; Tu, Jinhong; Hirano, Keiichi

1999-05-01

Human tissues obtained from cancerous kidneys fixed in formalin were observed with phase-contrast X-ray computed tomography (CT) using 17.7-keV synchrotron X-rays. By measuring the distributions of the X-ray phase shift caused by samples using an X-ray interferometer, sectional images that map the distribution of the refractive index were reconstructed. Because of the high sensitivity of phase- contrast X-ray CT, a cancerous lesion was differentiated from normal tissue and a variety of other structures were revealed without the need for staining.

Evaluation of cine CT in the investigation of patients with recurrent symptoms following coronary bypass grafting

International Nuclear Information System (INIS)

Rees, M.R.; MacMillan, R.M.; Eldredge, W.J.; Maranhao, V.

1986-01-01

Between May 1985 and July 1986, cine-CT was performed in 84 consecutive patients to evaluate graft patency and ventricular function. Only three studies (4%) were unsatisfactory. Compared to catheterization, an accuracy of 94% was found for graft patency, with a significant correlation for ejection fraction (r = .93). Close agreement with angiography was demonstrated for cine-CT detection of left ventricular wall motion abnormalities and graft flow. Compared to surgical placement, cine-CT localization of grafts in major coronary territories was 98% accurate. Despite a significant learning curve in study interpretation, cine-CT can be used in place of catheterization in the evaluation of symptomatic postgraft patients

The effect of introduction of axial cineangiography and echocardiography on contrast and radiation doses during cardiac catheterisation

International Nuclear Information System (INIS)

Sweet, E.M.; McLardy, J.L.

1984-01-01

The effects of routine preliminary echocardiography and adoption of axial cine angiography in a Paediatric Cardiac Investigation Centre were assessed in relation to contrast volume, fluoroscopy time and radiation dose. The results showed a significant increase in radiation dose with some reduction in fluoroscopy time in neonates and some increase in contrast volume used in infants [fr

Analyser-based phase contrast image reconstruction using geometrical optics

International Nuclear Information System (INIS)

Kitchen, M J; Pavlov, K M; Siu, K K W; Menk, R H; Tromba, G; Lewis, R A

2007-01-01

Analyser-based phase contrast imaging can provide radiographs of exceptional contrast at high resolution (<100 μm), whilst quantitative phase and attenuation information can be extracted using just two images when the approximations of geometrical optics are satisfied. Analytical phase retrieval can be performed by fitting the analyser rocking curve with a symmetric Pearson type VII function. The Pearson VII function provided at least a 10% better fit to experimentally measured rocking curves than linear or Gaussian functions. A test phantom, a hollow nylon cylinder, was imaged at 20 keV using a Si(1 1 1) analyser at the ELETTRA synchrotron radiation facility. Our phase retrieval method yielded a more accurate object reconstruction than methods based on a linear fit to the rocking curve. Where reconstructions failed to map expected values, calculations of the Takagi number permitted distinction between the violation of the geometrical optics conditions and the failure of curve fitting procedures. The need for synchronized object/detector translation stages was removed by using a large, divergent beam and imaging the object in segments. Our image acquisition and reconstruction procedure enables quantitative phase retrieval for systems with a divergent source and accounts for imperfections in the analyser

Phase-contrast x-ray computed tomography for observing biological specimens and organic materials

Science.gov (United States)

Momose, Atsushi; Takeda, Tohoru; Itai, Yuji

1995-02-01

A novel three-dimensional x-ray imaging method has been developed by combining a phase-contrast x-ray imaging technique with x-ray computed tomography. This phase-contrast x-ray computed tomography (PCX-CT) provides sectional images of organic specimens that would produce absorption-contrast x-ray CT images with little contrast. Comparing PCX-CT images of rat cerebellum and cancerous rabbit liver specimens with corresponding absorption-contrast CT images shows that PCX-CT is much more sensitive to the internal structure of organic specimens.

SU-F-T-263: Dosimetric Characteristics of the Cine Acquisition Mode of An A-Si EPID

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Bawazeer, O; Deb, P [RMIT University, Melbourne, VIC (Australia); Sarasanandarajah, S [Peter MacCallum Cancer Institute, Melbourne, Victoria (Australia); Herath, S; Kron, T [Peter MacCallum Cancer Institute, Melbourne, VIC (Australia)

2016-06-15

Purpose: To investigate the dosimetric characteristics of Varian a-Si-500 electronic portal imaging device (EPID) operated in cine mode particularly considering linearity with delivered dose, dose rate, field size, phantom thickness, MLC speed and common IMRT fields. Methods: The EPID that attached to a Varian Clinac 21iX linear accelerator, was irradiated with 6 and 18 MV using 600 MU/min. Image acquisition is controlled by the IAS3 software, Trigger delay was 6 ms, BeamOnDelay and FrameStartDelay were zero. Different frame rates were utilized. Cine mode response was calculated using MATLAB as summation of mean pixel values in a region of interest of the acquired images. The performance of cine mode was compared to integrated mode and dose measurements in water using CC13 ionization chamber. Results: Figure1 illustrates that cine mode has nonlinear response for small MU, when delivering 10 MU was about 0.5 and 0.64 for 6 and 18 MV respectively. This is because the missing acquired images that were calculated around four images missing in each delivery. With the increase MU the response became linear and comparable with integrated mode and ionization chamber within 2%. Figure 2 shows that cine mode has comparable response with integrated mode and ionization chamber within 2% with changing dose rate for 10 MU delivered. This indicates that the dose rate change has no effect on nonlinearity of cine mode response. Except nonlinearity, cine mode is well matched to integrated mode response within 2% for field size, phantom thickness, MLC speed dependences. Conclusion: Cine mode has similar dosimetric characteristics to integrated mode with open and IMRT fields, and the main limitation with cine mode is missing images. Therefore, the calibration of EPID images with this mode should be run with large MU, and when IMRT verification field has low MU, the correction for missing images are required.

SU-F-T-263: Dosimetric Characteristics of the Cine Acquisition Mode of An A-Si EPID

International Nuclear Information System (INIS)

Bawazeer, O; Deb, P; Sarasanandarajah, S; Herath, S; Kron, T

2016-01-01

Purpose: To investigate the dosimetric characteristics of Varian a-Si-500 electronic portal imaging device (EPID) operated in cine mode particularly considering linearity with delivered dose, dose rate, field size, phantom thickness, MLC speed and common IMRT fields. Methods: The EPID that attached to a Varian Clinac 21iX linear accelerator, was irradiated with 6 and 18 MV using 600 MU/min. Image acquisition is controlled by the IAS3 software, Trigger delay was 6 ms, BeamOnDelay and FrameStartDelay were zero. Different frame rates were utilized. Cine mode response was calculated using MATLAB as summation of mean pixel values in a region of interest of the acquired images. The performance of cine mode was compared to integrated mode and dose measurements in water using CC13 ionization chamber. Results: Figure1 illustrates that cine mode has nonlinear response for small MU, when delivering 10 MU was about 0.5 and 0.64 for 6 and 18 MV respectively. This is because the missing acquired images that were calculated around four images missing in each delivery. With the increase MU the response became linear and comparable with integrated mode and ionization chamber within 2%. Figure 2 shows that cine mode has comparable response with integrated mode and ionization chamber within 2% with changing dose rate for 10 MU delivered. This indicates that the dose rate change has no effect on nonlinearity of cine mode response. Except nonlinearity, cine mode is well matched to integrated mode response within 2% for field size, phantom thickness, MLC speed dependences. Conclusion: Cine mode has similar dosimetric characteristics to integrated mode with open and IMRT fields, and the main limitation with cine mode is missing images. Therefore, the calibration of EPID images with this mode should be run with large MU, and when IMRT verification field has low MU, the correction for missing images are required.

High sensitivity phase retrieval method in grating-based x-ray phase contrast imaging

Energy Technology Data Exchange (ETDEWEB)

Wu, Zhao; Gao, Kun; Chen, Jian; Wang, Dajiang; Wang, Shenghao; Chen, Heng; Bao, Yuan; Shao, Qigang; Wang, Zhili, E-mail: wangnsrl@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Zhang, Kai [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Zhu, Peiping; Wu, Ziyu, E-mail: wuzy@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China and Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2015-02-15

Purpose: Grating-based x-ray phase contrast imaging is considered as one of the most promising techniques for future medical imaging. Many different methods have been developed to retrieve phase signal, among which the phase stepping (PS) method is widely used. However, further practical implementations are hindered, due to its complex scanning mode and high radiation dose. In contrast, the reverse projection (RP) method is a novel fast and low dose extraction approach. In this contribution, the authors present a quantitative analysis of the noise properties of the refraction signals retrieved by the two methods and compare their sensitivities. Methods: Using the error propagation formula, the authors analyze theoretically the signal-to-noise ratios (SNRs) of the refraction images retrieved by the two methods. Then, the sensitivities of the two extraction methods are compared under an identical exposure dose. Numerical experiments are performed to validate the theoretical results and provide some quantitative insight. Results: The SNRs of the two methods are both dependent on the system parameters, but in different ways. Comparison between their sensitivities reveals that for the refraction signal, the RP method possesses a higher sensitivity, especially in the case of high visibility and/or at the edge of the object. Conclusions: Compared with the PS method, the RP method has a superior sensitivity and provides refraction images with a higher SNR. Therefore, one can obtain highly sensitive refraction images in grating-based phase contrast imaging. This is very important for future preclinical and clinical implementations.

High sensitivity phase retrieval method in grating-based x-ray phase contrast imaging

International Nuclear Information System (INIS)

Wu, Zhao; Gao, Kun; Chen, Jian; Wang, Dajiang; Wang, Shenghao; Chen, Heng; Bao, Yuan; Shao, Qigang; Wang, Zhili; Zhang, Kai; Zhu, Peiping; Wu, Ziyu

2015-01-01

Purpose: Grating-based x-ray phase contrast imaging is considered as one of the most promising techniques for future medical imaging. Many different methods have been developed to retrieve phase signal, among which the phase stepping (PS) method is widely used. However, further practical implementations are hindered, due to its complex scanning mode and high radiation dose. In contrast, the reverse projection (RP) method is a novel fast and low dose extraction approach. In this contribution, the authors present a quantitative analysis of the noise properties of the refraction signals retrieved by the two methods and compare their sensitivities. Methods: Using the error propagation formula, the authors analyze theoretically the signal-to-noise ratios (SNRs) of the refraction images retrieved by the two methods. Then, the sensitivities of the two extraction methods are compared under an identical exposure dose. Numerical experiments are performed to validate the theoretical results and provide some quantitative insight. Results: The SNRs of the two methods are both dependent on the system parameters, but in different ways. Comparison between their sensitivities reveals that for the refraction signal, the RP method possesses a higher sensitivity, especially in the case of high visibility and/or at the edge of the object. Conclusions: Compared with the PS method, the RP method has a superior sensitivity and provides refraction images with a higher SNR. Therefore, one can obtain highly sensitive refraction images in grating-based phase contrast imaging. This is very important for future preclinical and clinical implementations

Filmografía y bibliografía del cine negro americano (1930-1960

Directory of Open Access Journals (Sweden)

Dr. José Luis Sánchez Noriega

1999-01-01

Full Text Available La actualidad del cine negro queda patente con el éxito de crítica y de público de obras recientes como Casino (Martin Scorsese, 1995, La brigada del sombrero (Lee Tamahori, 1996, Al caer el sol (Robert Benton, 1996 o Donnie Brasco (Mike Newell, 1996. Hace unos meses han aparecido dos libros que se ocupan de este género y ofrecen una selección de un centenar de películas: El cine negro en 100 películas de Antonio Santamarina (Alianza, Madrid, 1999 y Obras maestras del cine negro (Mensajero, Bilbao, 1998, de quien firma estas líneas.

Analyser-based phase contrast image reconstruction using geometrical optics.

Science.gov (United States)

Kitchen, M J; Pavlov, K M; Siu, K K W; Menk, R H; Tromba, G; Lewis, R A

2007-07-21

Analyser-based phase contrast imaging can provide radiographs of exceptional contrast at high resolution (geometrical optics are satisfied. Analytical phase retrieval can be performed by fitting the analyser rocking curve with a symmetric Pearson type VII function. The Pearson VII function provided at least a 10% better fit to experimentally measured rocking curves than linear or Gaussian functions. A test phantom, a hollow nylon cylinder, was imaged at 20 keV using a Si(1 1 1) analyser at the ELETTRA synchrotron radiation facility. Our phase retrieval method yielded a more accurate object reconstruction than methods based on a linear fit to the rocking curve. Where reconstructions failed to map expected values, calculations of the Takagi number permitted distinction between the violation of the geometrical optics conditions and the failure of curve fitting procedures. The need for synchronized object/detector translation stages was removed by using a large, divergent beam and imaging the object in segments. Our image acquisition and reconstruction procedure enables quantitative phase retrieval for systems with a divergent source and accounts for imperfections in the analyser.

Cine MR imaging in mitral valve prolapse

International Nuclear Information System (INIS)

Kumai, Toshihiko

1993-01-01

This study was undertaken to assess the ability of cine MR imaging to evaluate the direction, timing, and severity of mitral regurgitation in patients with mitral valve prolapse (MVP). The population of this study was 33 patients with MVP diagnosed by two-dimensional echocardiography and 10 patients with rheumatic mitral valve disease (MSR) for comparison. 7 patients with MVP and 5 with MSR had atrial fibrillation and/or history of congestive heart failure as complications. Mitral regurgitation was graded for severity by color Doppler flow imaging in all patients. Direction and size of systolic flow void in the left atrium were analyzed by contiguous multilevel cine MR images and the maximum volumes of flow void and left atrium were measured. Although flow void was found at the center of the left atrium in most of MSR, it was often directed along the postero-caudal atrial wall in anterior leaflet prolapse and along the anterocranial atrial wall in posterior leaflet prolapse. In MVP, the maximum volume of flow void was often seen in late systole. The maximum volume of flow void and that of left atrium were significantly larger in patients with atrial fibrillation and/or history of congestive heart failure. The length and volume of flow void were increased with clinical severity and degree of regurgitation determined by color Doppler flow imaging. Thus cine MR imaging provides a useful means for detection and semiquantitative evaluation of mitral regurgitation in subjects with MVP. (author)

Cine MR imaging of the cardiovascular system

International Nuclear Information System (INIS)

Nishimura, Fumiaki; Yoshino, Yasushi; Mihara, Junji; Ichikawa, Seiichi; Kimura, Masahiko; Yano, Masao; Umeda, Masahiro; Oouchi, Toshihiro

1990-01-01

In recent years cine magnetic resonance imaging (MRI) has developed as a high-speed imaging technique that provides a high intensity signal even at a short repetition time (20-30 msec) by using an excited pulse with a small flip angle according to the gradient echo method, enabling about 20 to 30 continuous images of the same section per one cardiac cycle to be taken. On cine display of these continuous images, information concerning blood flow shown by a high intensity signal in comparison with that of the myocardium and vascular wall is obtained with high temporal resolution along with anatomical information. The present study reports the clinical usefulness of cine MRI in today's situation, inculding the following: calculation of the left ventricular ejection fraction and pulmonary-to-systemic flow ratio in congenital shunt disease by integration of the area of multisections through application of Simpson's method; diagnosis of the severity of valvular regurgitation, evaluation of stenosal diseases, and diagnosis of inflow from the fissured entry of dissecting aortic aneurysm by evaluating of an area of low intensity signal, probably based on the high velocity or turbulent blood flow: and evaluation of patency of the internal mammary artery bypass graft of the basis of the possible visualization of even thin blood vessels because of the high intensity signal of blood flow. In particular, the characteristics of this procedures are described by comparing it with other technologies in the field of diseases of valvular regurgitation. (author)

Value of cine MRI for better visualization of the proximal small bowel in normal individuals

International Nuclear Information System (INIS)

Torkzad, Michael R.; Blomqvist, Lennart; Vargas, Roberto; Tanaka, Chikako

2007-01-01

While enteroclysis seems to be the most efficacious method in achieving bowel distension, enterographic methods have become widespread due to the unpleasantness of enteroclysis and the radiation involved with positioning the catheter. Cine images in MRI can be done without radiation. Our aim is to see if and how cine MR imaging can improve visualization of bowel loops by capturing them while distended. Ten healthy individuals were asked to drink up to 2,000 ml of an oral solution made locally over a 60-min period. Then they underwent MRI using coronal balanced fast field echo (b-FFE) covering small bowel loops. If the initial exam revealed collapsed bowel loops an additional 50 mg of erythromycine was given intravenously with the subject still in the scanner and then cine imaging was performed. The degree of distension of different segments of the small bowel was measured before and after cine imaging and compared. The distension score was significantly higher after addition of the cine images as well, being only significant for depiction of the duodenum and jejunum. Our preliminary study suggests that cine MRI can give better image depiction of the proximal small bowel in healthy volunteers, perhaps circumventing the need for enteroclysis in some cases. There is a need for validation of these results in patients with small bowel disease. (orig.)

Slit-scanning differential phase-contrast mammography: first experimental results

Science.gov (United States)

Roessl, Ewald; Daerr, Heiner; Koehler, Thomas; Martens, Gerhard; van Stevendaal, Udo

2014-03-01

The demands for a large field-of-view (FOV) and the stringent requirements for a stable acquisition geometry rank among the major obstacles for the translation of grating-based, differential phase-contrast techniques from the laboratory to clinical applications. While for state-of-the-art Full-Field-Digital Mammography (FFDM) FOVs of 24 cm x 30 cm are common practice, the specifications for mechanical stability are naturally derived from the detector pixel size which ranges between 50 and 100 μm. However, in grating-based, phasecontrast imaging, the relative placement of the gratings in the interferometer must be guaranteed to within micro-meter precision. In this work we report on first experimental results on a phase-contrast x-ray imaging system based on the Philips MicroDose L30 mammography unit. With the proposed approach we achieve a FOV of about 65 mm x 175 mm by the use of the slit-scanning technique. The demand for mechanical stability on a micrometer scale was relaxed by the specific interferometer design, i.e., a rigid, actuator-free mount of the phase-grating G1 with respect to the analyzer-grating G2 onto a common steel frame. The image acquisition and formation processes are described and first phase-contrast images of a test object are presented. A brief discussion of the shortcomings of the current approach is given, including the level of remaining image artifacts and the relatively inefficient usage of the total available x-ray source output.

SU-E-J-192: Verification of 4D-MRI Internal Target Volume Using Cine MRI

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Lafata, K; Czito, B; Palta, M; Bashir, M; Yin, F; Cai, J [Duke University Medical Center, Durham, NC (United States)

2014-06-01

Purpose: To investigate the accuracy of 4D-MRI in determining the Internal Target Volume (ITV) used in radiation oncology treatment planning of liver cancers. Cine MRI is used as the standard baseline in establishing the feasibility and accuracy of 4D-MRI tumor motion within the liver. Methods: IRB approval was obtained for this retrospective study. Analysis was performed on MR images from four patients receiving external beam radiation therapy for liver cancer at our institution. Eligible patients received both Cine and 4D-MRI scans before treatment. Cine images were acquired sagittally in real time at a slice bisecting the tumor, while 4D images were acquired volumetrically. Cine MR DICOM headers were manipulated such that each respiratory frame was assigned a unique slice location. This approach permitted the treatment planning system (Eclipse, Varian Medical Systems) to recognize a complete respiratory cycle as a “volume”, where the gross tumor was contoured temporally. Software was developed to calculate the union of all frame contours in the structure set, resulting in the corresponding plane of the ITV projecting through the middle of the tumor, defined as the Internal Target Area (ITA). This was repeated for 4D-MRI, at the corresponding slice location, allowing a direct comparison of ITAs obtained from each modality. Results: Four patients have been analyzed. ITAs contoured from 4D-MRI correlate with contours from Cine MRI. The mean error of 4D values relative to Cine values is 7.67 +/− 2.55 %. No single ITA contoured from 4D-MRI demonstrated more than 10.5 % error compared to its Cine MRI counterpart. Conclusion: Motion management is a significant aspect of treatment planning within dynamic environments such as the liver, where diaphragmatic and cardiac activity influence plan accuracy. This small pilot study suggests that 4D-MRI based ITA measurements agree with Cine MRI based measurements, an important step towards clinical implementation. NIH 1R21

SU-E-J-192: Verification of 4D-MRI Internal Target Volume Using Cine MRI

International Nuclear Information System (INIS)

Lafata, K; Czito, B; Palta, M; Bashir, M; Yin, F; Cai, J

2014-01-01

Purpose: To investigate the accuracy of 4D-MRI in determining the Internal Target Volume (ITV) used in radiation oncology treatment planning of liver cancers. Cine MRI is used as the standard baseline in establishing the feasibility and accuracy of 4D-MRI tumor motion within the liver. Methods: IRB approval was obtained for this retrospective study. Analysis was performed on MR images from four patients receiving external beam radiation therapy for liver cancer at our institution. Eligible patients received both Cine and 4D-MRI scans before treatment. Cine images were acquired sagittally in real time at a slice bisecting the tumor, while 4D images were acquired volumetrically. Cine MR DICOM headers were manipulated such that each respiratory frame was assigned a unique slice location. This approach permitted the treatment planning system (Eclipse, Varian Medical Systems) to recognize a complete respiratory cycle as a “volume”, where the gross tumor was contoured temporally. Software was developed to calculate the union of all frame contours in the structure set, resulting in the corresponding plane of the ITV projecting through the middle of the tumor, defined as the Internal Target Area (ITA). This was repeated for 4D-MRI, at the corresponding slice location, allowing a direct comparison of ITAs obtained from each modality. Results: Four patients have been analyzed. ITAs contoured from 4D-MRI correlate with contours from Cine MRI. The mean error of 4D values relative to Cine values is 7.67 +/− 2.55 %. No single ITA contoured from 4D-MRI demonstrated more than 10.5 % error compared to its Cine MRI counterpart. Conclusion: Motion management is a significant aspect of treatment planning within dynamic environments such as the liver, where diaphragmatic and cardiac activity influence plan accuracy. This small pilot study suggests that 4D-MRI based ITA measurements agree with Cine MRI based measurements, an important step towards clinical implementation. NIH 1R21

Development of phase-contrast imaging technique for material science and medical science applications

International Nuclear Information System (INIS)

Kashyap, Y.S.; Roy, Tushar; Sarkar, P.S; Shukla, Mayank; Yadav, P.S; Sinha, Amar; Verma, Vishnu; Ghosh, A.K.

2007-07-01

In-line phase contrast imaging technique is an emerging method for study of materials such as carbon fibres, carbon composite materials, polymers etc. These represent the class of materials for which x-ray attenuation cross-section is very small. Similarly, this technique is also well suited for imaging of soft materials such as tissues, distinguishing between tumour and normal tissue. Thus this method promises a far better contrast for low x-ray absorbing substances than the conventional radiography method for material and medical science applications. Though the conventional radiography technique has been carried out for decades, the phase-imaging technique is being demonstrated for the first time within, the country. We have set up an experimental facility for phase contrast imaging using a combination of x-ray CCD detector and a microfocus x-ray source. This facility is dedicated for micro-imaging experiments such as micro-tomography and high resolution phase contrast experiments. In this report, the results of phase contrast imaging using microfocus source and ELETTRA, synchrotron source are discussed. We have also discussed the basic design and heat load calculation for upcoming imaging beamline at Indus-II, RRCAT, Indore. (author)

Assessment of Left Ventricular Function and Mass on Free-Breathing Compressed Sensing Real-Time Cine Imaging.

Science.gov (United States)

Kido, Tomoyuki; Kido, Teruhito; Nakamura, Masashi; Watanabe, Kouki; Schmidt, Michaela; Forman, Christoph; Mochizuki, Teruhito

2017-09-25

Compressed sensing (CS) cine magnetic resonance imaging (MRI) has the advantage of being inherently insensitive to respiratory motion. This study compared the accuracy of free-breathing (FB) CS and breath-hold (BH) standard cine MRI for left ventricular (LV) volume assessment.Methods and Results:Sixty-three patients underwent cine MRI with both techniques. Both types of images were acquired in stacks of 8 short-axis slices (temporal/spatial resolution, 41 ms/1.7×1.7×6 mm 3 ) and compared for ejection fraction, end-diastolic and systolic volumes, stroke volume, and LV mass. Both BH standard and FB CS cine MRI provided acceptable image quality for LV volumetric analysis (score ≥3) in all patients (4.7±0.5 and 3.7±0.5, respectively; Pcine MRI (median, IQR: BH standard, 83.8 mL, 64.7-102.7 mL; FB CS, 79.0 mL, 66.0-101.0 mL; P=0.0006). The total acquisition times for BH standard and FB CS cine MRI were 113±7 s and 24±4 s, respectively (Pcine MRI is a clinically useful alternative to BH standard cine MRI in patients with impaired BH capacity.

Assessment of voluntary deep inspiration breath-hold with CINE imaging for breast radiotherapy.

Science.gov (United States)

Estoesta, Reuben Patrick; Attwood, Lani; Naehrig, Diana; Claridge-Mackonis, Elizabeth; Odgers, David; Martin, Darren; Pham, Melissa; Toohey, Joanne; Carroll, Susan

2017-10-01

Deep Inspiration Breath-Hold (DIBH) techniques for breast cancer radiation therapy (RT) have reduced cardiac dose compared to Free Breathing (FB). Recently, a voluntary deep inspiration breath-hold (vDIBH) technique was established using in-room lasers and skin tattoos to monitor breath-hold. An in-house quality assessment of positional reproducibility during RT delivery with vDIBH in patients with left-sided breast cancer was evaluated. The electronic portal imaging device (EPID) was used in cinematographic (CINE) mode to capture a sequence of images during beam delivery. Weekly CINE images were retrospectively assessed for 20 left-sided breast cancer patients receiving RT in vDIBH, and compared with CINE images of 20 patients treated in FB. The intra-beam motion was assessed and the distance from the beam central axis (CA) to the internal chest wall (ICW) was measured on each CINE image. These were then compared to the planned distance on digitally reconstructed radiograph (DRR). The maximum intra-beam motion for any one patient measurement was 0.30 cm for vDIBH and 0.20 cm for FB. The mean difference between the distance from the CA to ICW on DRR and the equivalent distance on CINE imaging (as treated) was 0.28 cm (SD 0.17) for vDIBH patients and 0.25 cm (SD 0.14) for FB patients (P = 0.458). The measured values were comparable for patients undergoing RT in vDIBH, and for those in FB. This quality assessment showed that using in-room lasers and skin tattoos to independently monitor breath-hold in vDIBH as detected by 'on-treatment' CINE imaging is safe and effective. © 2017 The Royal Australian and New Zealand College of Radiologists.

El cine o la teoría del presentimiento

OpenAIRE

Santiago Rivadeneira

2015-01-01

El cine es el triunfo de la alegoría sobre la realidad a partir de un "protocolo visual" que se cumple de modo inexorable, como la realización de un sueño estético permanente soñado. El cine está destinado a convertirse siempre más en la conciencia colectiva, en el ligamen que nos une a todos. Alegoría y presentimiento que se juntan para explorar la realidad, la percepción, el significado, la conciencia y la imaginación, expuesto de alguna manera en las breves alegorías de Kafka. Alegoría, re...

Synchrotron Based Phase Contrast Tomography of Hyper cholesteromic Rat Liver

Directory of Open Access Journals (Sweden)

Fatima A

2017-05-01

Full Text Available X-ray phase contrast imaging technique has been applied for the study of morphological variations in soft tissues. The effect of an antioxidant, α-lipoic acid in reducing hypercholesterolemia in rats is investigated. The experiment was conducted to measure serum lipid profile and diameter of vessels in rat liver, as liver is the most vital organ in hypolipidemic activity studies. Methods: Four groups of male Wistar rats, control (Group I, hyperlipidemic (Group II, positive control (Group III and treated Group IV were studied for serum lipid profile and liver vessels with synchrotron X-ray phase tomography. The Group I rats received chow diet, in Group II rats, administration of 20% butter rich diet induced hyperlipidemia. Group III, treated rats received hypolipidemic drug Atorvastatin and Group IV animals received a potent antioxidant DL-α-Lipoic acid. The excised liver tissue immersed in 10% formalin. X-ray phase contrast tomography was performed for comparison of diameter of liver vessels. Results: Among the four group of animals, the diameter of liver vessels was much larger in hypercholesterolemic rat (Group II. The liver vessel diameter comparison with X-ray phase contrast tomography and the lipid profile shows reduction in serum lipids and lipoproteins by ALA treatment.

First principles study of the optical contrast in phase change materials

Energy Technology Data Exchange (ETDEWEB)

Caravati, S; Parrinello, M [Department of Chemistry and Applied Biosciences, ETH Zurich, USI Campus, Via Giuseppe Buffi 13, 6900 Lugano (Switzerland); Bernasconi, M, E-mail: marco.bernasconi@mater.unimib.i [Dipartimento di Scienza dei Materiali, Universita di Milano-Bicocca, Via R Cozzi 53, I-20125, Milano (Italy)

2010-08-11

We study from first principles the optical properties of the phase change materials Ge{sub 2}Sb{sub 2}Te{sub 5} (GST), GeTe and Sb{sub 2}Te{sub 3} in the crystalline phase and in realistic models of the amorphous phase generated by quenching from the melt in ab initio molecular dynamics simulations. The calculations reproduce the strong optical contrast between the crystalline and amorphous phases measured experimentally and exploited in optical data storage. It is demonstrated that the optical contrast is due to a change in the optical matrix elements across the phase change in all the compounds. It is concluded that the reduction of the optical matrix elements in the amorphous phases is due to angular disorder in p-bonding which dominates the amorphous network in agreement with previous proposals (Huang and Robertson 2010 Phys. Rev. B 81 081204) based on calculations on crystalline models.

Three-dimensional MRI-linac intra-fraction guidance using multiple orthogonal cine-MRI planes.

Science.gov (United States)

Bjerre, Troels; Crijns, Sjoerd; af Rosenschöld, Per Munck; Aznar, Marianne; Specht, Lena; Larsen, Rasmus; Keall, Paul

2013-07-21

The introduction of integrated MRI-radiation therapy systems will offer live intra-fraction imaging. We propose a feasible low-latency multi-plane MRI-linac guidance strategy. In this work we demonstrate how interleaved acquired, orthogonal cine-MRI planes can be used for low-latency tracking of the 3D trajectory of a soft-tissue target structure. The proposed strategy relies on acquiring a pre-treatment 3D breath-hold scan, extracting a 3D target template and performing template matching between this 3D template and pairs of orthogonal 2D cine-MRI planes intersecting the target motion path. For a 60 s free-breathing series of orthogonal cine-MRI planes, we demonstrate that the method was capable of accurately tracking the respiration related 3D motion of the left kidney. Quantitative evaluation of the method using a dataset designed for this purpose revealed a translational error of 1.15 mm for a translation of 39.9 mm. We have demonstrated how interleaved acquired, orthogonal cine-MRI planes can be used for online tracking of soft-tissue target volumes.

Visualization and quantification of large bowel motility with functional cine-MRI

International Nuclear Information System (INIS)

Buhmann, S.; Wielage, C.; Fischer, T.; Reiser, M.; Lienemann, A.; Kirchhoff, C.; Mussack, T.

2005-01-01

Purpose: to develop and evaluate a method to visualize and quantify large bowel motility using functional cine MRI. Methods: fifteen healthy individuals (8males, 7 females, 20 to 45 years old) with no history or present symptoms of bowel disorders were enrolled in a functional cine MRI examination at 6 a. m. after a starving phase for at least eight hours before and after oral administration of Senna tea (mild stimulating purgative). Two consecutive sets of repeated measurements of the entire abdomen were performed using a 1.5T MRI system with coronal T2-weighted HASTE sequences anatomically adjusted to the course of the large bowel. A navigator technique was used for respiratory gating at the level of the right dorsal diaphragm. The changes in diameter (given in cm) were measured at 5 different locations of the ascending (AC), transverse (TC) and descending colon (DC), and assessed as parameters for the bowel motility. Results: the mean values as a statistical measure for large bowel relaxation were determined. Before ingestion of Senna tea, the mean diameter measured 3.41 cm (ascending colon), 3 cm (transverse colon) and 2.67 cm (descending colon). After the ingestion of Senna tea, the mean diameter increased to 3.69 cm (ascending colon) to 3.4 cm (transverse colon) and to 2.9 cm (descending colon). A statistically significant difference was demonstrated with the Wilcoxon test (level of confidence 0.05). For the determination of dynamic increase, the changes of the statistical scatter amplitude to the mean value were expressed as percentage before and after the ingestion of Senna tea. Thereby, an increase in variation and dynamic range was detected for the AC (112.9%) and DC (100%), but a decrease in the dynamics for the TC (69%). Conclusion: a non-invasive method for the assessment of bowel motility was developed for the first time. The use of functional cine MRI utilizing a prokinetic stimulus allowed visualisation and quantification of large bowel motility

Accuracy of accelerated cine MR imaging at 3 Tesla in longitudinal follow-up of cardiac function

International Nuclear Information System (INIS)

Sandner, Torleif A.; Huber, Armin M.; Theisen, Daniel; Reiser, Maximilian F.; Wintersperger, Bernd J.; Houck, Philip; Runge, Val M.; Sincleair, Spencer

2008-01-01

The ability of fast, parallel-imaging-based cine magnetic resonance (MR) to monitor global cardiac function in longitudinal exams at 3 Tesla was evaluated. Seventeen patients with chronic cardiac disease underwent serial cine MR imaging exams (n=3) at 3 Tesla. Data were acquired in short-axis orientation using cine steady-state free precession (SSFP) with a spatial resolution of 2.5 x 1.9 mm 2 at 45 ms temporal resolution. Multislice imaging (three slices/breath-hold) was performed using TSENSE acceleration (R=3) and standard single-slice cine (non-TSENSE) was performed at identical locations in consecutive breath-holds. End-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF) and myocardial mass (MM) of both cine approaches were compared for individual time-points as well as for longitudinal comparison. TSENSE-cine did not show significant differences for EDV (2.6 ml; P=.79), ESV (2.2 ml; P=0.81), EF (-0.3%; P=0.95) and MM (2.4 g; P=0.72) in comparison with non-TSENSE. Longitudinal ANOVA analysis did not reveal significant differences for any parameter, neither for non-TSENSE data (all P>0.7) nor for TSENSE data (all P>0.9). Multifactorial ANOVA showed non-significant differences (all P>0.7) at comparable data variances. Data acquisition was significantly shortened using TSENSE. Threefold accelerated multislice cine at 3 Tesla allows accurate assessment of volumetric LV data and accurate longitudinal monitoring of global LV function at a substantially shorter overall examination time. (orig.)

Image processing in cine-scintigraphy. Organization of the CINE 200 system

International Nuclear Information System (INIS)

Tournier, E.; Axelrad, C.; Monge, J.; Beccia, A.; Bouvier, A.

1975-01-01

The CINE 200 system, although using a small computer to reduce costs, is shown to be a highly efficient instrument for the processing of scintigraphic images. This was achieved by creating an acquisition and display system branched directly onto the memory, reducing the processing times by the writing of fast micro-programmes, and cutting down the place occupied by the programmes in the live memory by a good organization of these programmes. This internal organization of the system, the insertion and role of the programmes, the data organization and the working procedure are described briefly [fr

Discursos subversivos en el cine no hablado

Directory of Open Access Journals (Sweden)

Rodríguez Fernández, M.ª del Carmen

2012-12-01

Full Text Available “Subversive discourses in silent films” aims to analyse the gender transgression that emerges in certain movies of the silent period. These being silent films, their meaning can only be understood from the content of the images. Directors of the silent period were aware of the importance of images and of their power to put across their views to spectators. The field of filmmaking was new but it was not ungendered, and women filmmakers knew that their films were the vehicle to make spectators aware of their feminist positions. Le matelas alcoolique, La souriante Mme. Beudet and Dora Films of America Shorts are examples of this privilege since, although they belong to two periods of silent film history and have different aims, the directors and the films selected are good examples to be revisited with a gender perspective.

“Discursos subversivos en el cine no hablado” se propone analizar las transgresiones de género que aparecen en algunas películas del cine mudo. Por sus características al tratarse de un cine no hablado, lo que sugieren algunas imágenes es fundamental para entender los significados de las películas. Las directoras de aquella época eran conocedoras de la importancia de las imágenes y del poder que les confería la cámara para expresar sus reivindicaciones al público espectador. El campo de la cinematografía era nuevo, pero tenía género y las directoras sabían que sus películas eran el vehículo para dar a conocer su articulación como feministas. Le matelas alcoolique, La souriante Mme. Beudet y Dora Films of America Shorts son ejemplos de este privilegio puesto que, aunque las películas de esta muestra pertenezcan a dos etapas del cine mudo y de que sus propósitos fueran diferentes, las directoras y las películas seleccionadas son ejemplos merecedores de una revisión con perspectiva de género.

Cerebrospinal fluid pulsation amplitude and its quantitative relationship to cerebral blood flow pulsations: a phase-contrast MR flow imaging study

International Nuclear Information System (INIS)

Bhadelia, R.A.; Bogdan, A.R.; Kaplan, R.F.; Wolpert, S.M.

1997-01-01

Our purpose in this investigation was to explain the heterogeneity in the cerebrospinal fluid (CSF) flow pulsation amplitudes. To this end, we determined the contributions of the cerebral arterial and jugular venous flow pulsations to the amplitude of the CSF pulsation. We examined 21 healthy subjects by cine phase-contrast MRI at the C2-3 disc level to demonstrate the CSF and vascular flows as waveforms. Multiple regression analysis was performed to calculate the contributions of (a) the arterial and venous waveform amplitudes and (b) the delay between the maximum systolic slopes of the arterial and venous waveforms (AV delay), in order to predict the amplitude of the CSF waveform. The contribution of the arterial waveform amplitude was positive (r = 0.61; p 0.003) to the CSF waveform amplitude and that of the venous waveform amplitude was negative (r = -0.50; p = 0.006). Both in combination accounted for 56 % of the variance in predicting the CSF waveform amplitude (p < 0.0006). The contribution of AV delay was not significant. The results show that the variance in the CSF flow pulsation amplitudes can be explained by concurrent evaluation of the CSF and vascular flows. Improvement in the techniques, and controlled experiments, may allow use of CSF flow pulsation amplitudes for clinical applications in the non-invasive assessment of intracranial dynamics by MRI. (orig.). With 3 figs., 2 tabs

Routine Cine-CMR for Prosthesis Associated Mitral Regurgitation – A Multicenter Comparison to Echocardiography

Science.gov (United States)

Simprini, Lauren A.; Afroz, Anika; Cooper, Mitchell A.; Klem, Igor; Jensen, Christoph; Kim, Raymond J.; Srichai, Monvadi B.; Heitner, John F.; Sood, Michael; Chandy, Elizabeth; Shah, Dipan J.; Lopez-Mattei, Juan; Biederman, Robert W.; Grizzard, John D.; Fuisz, Anthon; Ghafourian, Kambiz; Farzaneh-Far, Afshin; Weinsaft, Jonathan

2016-01-01

Background/Aim MR is an important complication after PMV. Transthoracic echocardiography is widely used to screen for native MR, but can be limited with PMV. Cine-CMR holds potential to non-invasively assess regurgitant severity based on MR-induced inter-voxel dephasing. This study evaluated routine cine-CMR for visual assessment of prosthetic mitral valve (PMV) associated mitral regurgitation (MR). Methods Routine cine-CMR was performed at 9 sites. A uniform protocol was used to grade MR based on jet size in relation to the left atrium (mild 2/3): MR was graded in each long axis orientation, with overall severity based on cumulative grade. Cine-CMR was also scored for MR density and pulmonary vein systolic flow reversal (PSFR). Visual interpretation was compared to quantitative analysis in a single center (derivation) cohort, and to transesophageal echocardiography (TEE) in a multicenter (validation) cohort. Results The population comprised 85 PMV patients (59% mechanical, 41% bioprosthetic). Among the derivation cohort (n=25), quantitative indices paralleled visual scores, with stepwise increases in jet size and density in relation to visually graded MR severity (both p=0.001): Patients with severe MR had nearly a 3-fold increase in quantitative jet area (p=0.002), and 2-fold increase in density (p=0.04) than did others. Among the multicenter cohort, cine-CMR and TEE (Δ=2±3 days) demonstrated moderate agreement (κ=0.44); 64% of discordances differed by ≤ 1 grade (Δ=1.2±0.5). Using a TEE reference, cine-CMR yielded excellent diagnostic performance for severe MR (sensitivity, negative predictive value=100%). Patients with visually graded severe MR also had more frequent PVSFR (pcine-CMR. Conclusions Cine-CMR is useful for assessment of PMV-associated MR, which manifests concordant quantitative and qualitative changes in size and density of inter-voxel dephasing. Visual MR assessment based on jet size provides an accurate non-invasive means of screening for

Physiologic AV valvular insufficiency in cine MR imaging

Energy Technology Data Exchange (ETDEWEB)

Jang, Yoon Hyung; Kang, Eun Joo; Baik, Seung Kug; Ahn, Woo Hyun; Choi, Han Yong; Kim, Bong Gi [Wallace Memorial Baptist Hospital, Pusan (Korea, Republic of)

1994-05-15

To give a help in the interpretation of cardiac cine-MR examination, the extent, shape, and timing of appearance of signal void regions near atrioventricular(A-V) valve prospectively evaluate in the healthy population. Using an axial gradient-echo technique with small flip angle, repetition time(TR) of 36 msec and echo time(TE) of 22 msec, 20 volunteers without known valvular abnormalities undertook cardiac cine-MR imaging including atrioventricular valve areas. Transient signal void was observed within the near the tricuspid(13/20 = 65%) and mitral valves(9/20 = 45%), respectively, which is so called {sup p}hysioloic atrioventricular valvular insufficiency{sup .} Eight subjects revealed the signal void areas near both tricuspid and mitral valves but, 5 subjects did not show any evidence of physiologic insufficiency. This physiologic condition does not extend more than 1 cm proximal to A-V valve plane and is generally observed only during early systole. Its morphology is semilunar or triangular configuration with the base to the valve plane in most cases of normal tricuspid insufficiency and small globular appearance in most cases of normal mitral insufficiency. Awareness of normal signal void areas near the A-V valve and their characteristics is critical in the interpretation of cardiac cine MR examinations and maybe helpful in the study of the normal cardiac physiology.

Physiologic AV valvular insufficiency in cine MR imaging

International Nuclear Information System (INIS)

Jang, Yoon Hyung; Kang, Eun Joo; Baik, Seung Kug; Ahn, Woo Hyun; Choi, Han Yong; Kim, Bong Gi

1994-01-01

To give a help in the interpretation of cardiac cine-MR examination, the extent, shape, and timing of appearance of signal void regions near atrioventricular(A-V) valve prospectively evaluate in the healthy population. Using an axial gradient-echo technique with small flip angle, repetition time(TR) of 36 msec and echo time(TE) of 22 msec, 20 volunteers without known valvular abnormalities undertook cardiac cine-MR imaging including atrioventricular valve areas. Transient signal void was observed within the near the tricuspid(13/20 = 65%) and mitral valves(9/20 = 45%), respectively, which is so called p hysioloic atrioventricular valvular insufficiency . Eight subjects revealed the signal void areas near both tricuspid and mitral valves but, 5 subjects did not show any evidence of physiologic insufficiency. This physiologic condition does not extend more than 1 cm proximal to A-V valve plane and is generally observed only during early systole. Its morphology is semilunar or triangular configuration with the base to the valve plane in most cases of normal tricuspid insufficiency and small globular appearance in most cases of normal mitral insufficiency. Awareness of normal signal void areas near the A-V valve and their characteristics is critical in the interpretation of cardiac cine MR examinations and maybe helpful in the study of the normal cardiac physiology

Analysis of blood flow patterns in aortic aneurysm by cine magnetic resonance imaging

International Nuclear Information System (INIS)

Matsuoka, Hiroshi

1993-01-01

Cine MRI (0.5 T) using rephased gradient echo technique was performed to study the patterns of blood flow in the aortic aneurysm of 16 patients with aortic aneurysm, and the data were compared with those of 5 healthy volunteers. In the transaxial section, the blood flow in normal aorta appeared as homogeneous high intensity during systole. On the other hand, the blood flow in the aneurysm appeared as inhomogeneous flow enhancement with flow void. In the sagittal scan, the homogeneous flow enhancement in a normal aorta was also observed during systole and its apex of flow enhancement was 'taper'. The blood flow patterns in the aneurysm were classified as 'irregular', 'zonal', 'eddy', and 'obscure' depending on the contrast of flow enhancement and flow void. Their apexes were 'taper' or 'round'. The blood flow patterns in the aneurysm were related to the size of aneurysm. In patients with a large size 'aneurysm, their flow patterns were 'eddy' or 'obscure' and the flow enhancement was 'round'. On the other hand, in patients with a small size aneurysm, their flow patterns were 'irregular' or 'zonal', and their flow enhancement was 'taper'. Though the exact mechanism of abnormal flow patterns in an aortic aneurysm remains to be determined, cine MRI gives helpful informations in assessing blood flow dynamics in the aneurysm. (author)

Reflexionando sobre la vejez a través del cine. Una aproximación incompleta

OpenAIRE

Pinazo Hernandis, Sacramento

2013-01-01

Reflexionando sobre la vejez a través del cine. Una aproximación incompleta Existen en la sociedad muchos estereotipos y prejuicios en torno a las personas mayores, que se reflejan tanto en la vida cotidiana como en los medios de comunicación y también en el cine. En una sociedad audiovisual como la nuestra, la imagen es una importante fuente de conocimiento, y el cine se convierte en un excelente recurso didáctico para favorecer y motivar el proceso de enseñanza-aprendizaje; es una excelente...

Feasibility of free-breathing, GRAPPA-based, real-time cardiac cine assessment of left-ventricular function in cardiovascular patients at 3 T

International Nuclear Information System (INIS)

Zhu, Xiaomei; Schwab, Felix; Marcus, Roy; Hetterich, Holger; Theisen, Daniel; Kramer, Harald; Notohamiprodjo, Mike; Schlett, Christopher L.; Nikolaou, Konstantin; Reiser, Maximilian F.

2015-01-01

Highlights: • Grappa-based real time cine cardiac MRI is feasible for assessment of left ventricular function. • Significant underestimation of systolic function, peak ejection and filling rates needs to be considered. • Heart rate is the only positive predictor of the deviation of obtained parameters. - Abstract: Objectives: To determine the feasibility of free-breathing, GRAPPA-based, real-time (RT) cine 3 T cardiac magnetic resonance imaging (MRI) with high acceleration factors for the assessment of left-ventricular function in a cohort of patients as compared to conventional segmented cine imaging. Materials and methods: In this prospective cohort study, subjects with various cardiac conditions underwent MRI involving two RT cine sequences (high resolution and low resolution) and standard segmented cine imaging. Standard qualitative and quantitative parameters of left-ventricular function were quantified. Results: Among 25 subjects, 24 were included in the analysis (mean age: 50.5 ± 21 years, 67% male, 25% with cardiomyopathy). RT cine derived quantitative parameters of volumes and left ventricular mass were strongly correlated with segmented cine imaging (intraclass correlation coefficient [ICC]: >0.72 for both RT cines) but correlation for peak ejection and filling rates were moderate to poor for both RT cines (ICC < 0.40). Similarly, RT cines significantly underestimated peak ejection and filling rates (>103.2 ± 178 ml/s). Among patient-related factors, heart rate was strongly predictive for deviation of measurements (p < 0.05). Conclusions: RT cine MRI at 3 T is feasible for qualitative and quantitative assessment of left ventricular function for low and high-resolution sequences but results in significant underestimation of systolic function, peak ejection and filling rates

Initial studies of synchrotron radiation phase-contrast imaging in the field of medicine

International Nuclear Information System (INIS)

Chen Shaoliang; Zhang Xi; Peng Yifeng; Li Beilei; Cheng Aiping; Zhu Peiping; Yuan Xiqing; Huang Wanxia

2010-01-01

Recently,research on using X-ray phase information in medicine has been growing remarkably fast. Phase-contrast imaging with synchrotron radiation can reveal inner soft tissues such as tendons, cartilage, ligaments, adipose tissue, vessels and nerves without a contrast agent. We have visualized the liver, bile duct, lung, kidney, stomach and intestine, heart, blood vessel, bone and arthrosis, and tumor tissues using 'in-line' phase contrast imaging and diffraction-enhanced imaging. It is seen that the synchrotron radiation graphs show much higher resolution. This method is especially suitable for studying soft tissue structure and blood vessels. (authors)

A methodology to accurately quantify patellofemoral cartilage contact kinematics by combining 3D image shape registration and cine-PC MRI velocity data.

Science.gov (United States)

Borotikar, Bhushan S; Sipprell, William H; Wible, Emily E; Sheehan, Frances T

2012-04-05

Patellofemoral osteoarthritis and its potential precursor patellofemoral pain syndrome (PFPS) are common, costly, and debilitating diseases. PFPS has been shown to be associated with altered patellofemoral joint mechanics; however, an actual variation in joint contact stresses has not been established due to challenges in accurately quantifying in vivo contact kinematics (area and location). This study developed and validated a method for tracking dynamic, in vivo cartilage contact kinematics by combining three magnetic resonance imaging (MRI) techniques, cine-phase contrast (CPC), multi-plane cine (MPC), and 3D high-resolution static imaging. CPC and MPC data were acquired from 12 healthy volunteers while they actively extended/flexed their knee within the MRI scanner. Since no gold standard exists for the quantification of in vivo dynamic cartilage contact kinematics, the accuracy of tracking a single point (patellar origin relative to the femur) represented the accuracy of tracking the kinematics of an entire surface. The accuracy was determined by the average absolute error between the PF kinematics derived through registration of MPC images to a static model and those derived through integration of the CPC velocity data. The accuracy ranged from 0.47 mm to 0.77 mm for the patella and femur and from 0.68 mm to 0.86 mm for the patellofemoral joint. For purely quantifying joint kinematics, CPC remains an analytically simpler and more accurate (accuracy <0.33 mm) technique. However, for application requiring the tracking of an entire surface, such as quantifying cartilage contact kinematics, this combined imaging approach produces accurate results with minimal operator intervention. Published by Elsevier Ltd.

A phase contrast interferometer on DIII-D

International Nuclear Information System (INIS)

Coda, S.; Porkolab, M.; Carlstrom, T.N.

1992-04-01

A novel imaging diagnostic has recently become operational on the DIII-D tokamak for the study of density fluctuations at the outer edge of the plasma. The phase contrast imaging approach overcomes the limitations of conventional scattering techniques in the spectral range of interest for transport-related phenomena, by allowing detection of long wavelength modes (up to 7.6 cm) with excellent spatial resolution (5 mm) in the radial direction. Additional motivation for the diagnostic is provided by wave-plasma interactions during heating and current drive experiments in the Ion Cyclotron range of frequencies. Density perturbations of 4 x 10 7 cm -3 with a 1 MHz bandwidth can be resolved. The diagnostic employs a 7.6 cm diameter CO 2 laser beam launched vertically across the plasma edge. An image of the plasma is then created on a 16-element detector array: the detector signals are directly proportional to the density fluctuations integrated along each chord. Wavelengths and correlation lengths can be inferred from the spatial mapping. The phase contrast method and its application to DIII-D are described and tests and first plasma data are presented

Holistic segmentation of the lung in cine MRI.

Science.gov (United States)

Kovacs, William; Hsieh, Nathan; Roth, Holger; Nnamdi-Emeratom, Chioma; Bandettini, W Patricia; Arai, Andrew; Mankodi, Ami; Summers, Ronald M; Yao, Jianhua

2017-10-01

Duchenne muscular dystrophy (DMD) is a childhood-onset neuromuscular disease that results in the degeneration of muscle, starting in the extremities, before progressing to more vital areas, such as the lungs. Respiratory failure and pneumonia due to respiratory muscle weakness lead to hospitalization and early mortality. However, tracking the disease in this region can be difficult, as current methods are based on breathing tests and are incapable of distinguishing between muscle involvements. Cine MRI scans give insight into respiratory muscle movements, but the images suffer due to low spatial resolution and poor signal-to-noise ratio. Thus, a robust lung segmentation method is required for accurate analysis of the lung and respiratory muscle movement. We deployed a deep learning approach that utilizes sequence-specific prior information to assist the segmentation of lung in cine MRI. More specifically, we adopt a holistically nested network to conduct image-to-image holistic training and prediction. One frame of the cine MRI is used in the training and applied to the remainder of the sequence ([Formula: see text] frames). We applied this method to cine MRIs of the lung in the axial, sagittal, and coronal planes. Characteristic lung motion patterns during the breathing cycle were then derived from the segmentations and used for diagnosis. Our data set consisted of 31 young boys, age [Formula: see text] years, 15 of whom suffered from DMD. The remaining 16 subjects were age-matched healthy volunteers. For validation, slices from inspiratory and expiratory cycles were manually segmented and compared with results obtained from our method. The Dice similarity coefficient for the deep learning-based method was [Formula: see text] for the sagittal view, [Formula: see text] for the axial view, and [Formula: see text] for the coronal view. The holistic neural network approach was compared with an approach using Demon's registration and showed superior performance. These

La mujer española y el cine español

Directory of Open Access Journals (Sweden)

Dolores Barbazán Capeáns

2012-08-01

Full Text Available El cine es un elemento motivador para el aprendizaje de español como lenguaextranjera, así como un recurso didáctico esencial (Romea 2003, Brandimonte 2003.Con el uso del cine en clase de lenguas se les introducen a los estudiantes contenidosculturales, sociales y económicos (Herrero 2008. El objetivo de este trabajo es lapresentación de una unidad didáctica sobre las mujeres españolas y el cine español,dirigida a estudiantes chinos en un contexto de inmersión en Tarragona. Los estudiantestienen un nivel B2 siguiendo el Marco Común Europeo de Referencia: enseñanza,aprendizaje y evaluación (MCER 2002. Se sigue un enfoque comunicativo por tareas.La duración de la unidad didáctica es de aproximadamente cuatro horas y media. Suaplicación en el aula ha resultado enriquecedora y contó con muy buena acogida porparte de los estudiantes.

Hemodynamic aspects of mitral regurgitation assessed by generalized phase-contrast MRI

OpenAIRE

Dyverfeldt, Petter; Escobar Kvitting, John-Peder; Carlhäll, Carl Johan; Boano, Gabriella; Sigfridsson, Andreas; Hermansson, Ulf; Bolger, Ann F.; Engvall, Jan; Ebbers, Tino

2011-01-01

Purpose: Mitral regurgitation creates a high velocity jet into the left atrium (LA), contributing both volume andpressure; we hypothesized that the severity of regurgitation would be reflected in the degree of LA flowdistortion. Material and Methods: Three-dimensional cine PC-MRI was applied to determine LA flow patterns andturbulent kinetic energy (TKE) in seven subjects (five patients with posterior mitral leaflet prolapse, two normalsubjects). In addition, the regurgitant volume and the ti...

Analyzer-based x-ray phase-contrast microscopy combining channel-cut and asymmetrically cut crystals

International Nuclear Information System (INIS)

Hoennicke, M. G.; Cusatis, C.

2007-01-01

An analyzer-based x-ray phase-contrast microscopy (ABM) setup combining a standard analyzer-based x-ray phase-contrast imaging (ABI) setup [nondispersive 4-crystal setup (Bonse-Hart setup)] and diffraction by asymmetrically cut crystals is presented here. An attenuation-contrast microscopy setup with conventional x-ray source and asymmetrically cut crystals is first analyzed. Edge-enhanced effects attributed to phase jumps or refraction/total external reflection on the fiber borders were detected. However, the long exposure times and the possibility to achieve high contrast microscopies by using extremely low attenuation-contrast samples motivated us to assemble the ABM setup using a synchrotron source. This setup was found to be useful for low contrast attenuation samples due to the low exposure time, high contrast, and spatial resolution found. Moreover, thanks to the combination with the nondispersive ABI setup, the diffraction-enhanced x-ray imaging algorithm could be applied

KOT: El boxeo en el cine mexicano

OpenAIRE

Orozco-Martínez, Carlos E.

1986-01-01

Texto sobre el género de boxeadores en el cine mexicano. Se habla de la trama de este tipo de filmes, de los personajes comunes, sus orígenes, algunas películas representativas y de los directores que trataron la temática.

Comparison of hemodynamics of intracranial aneurysms between MR fluid dynamics using 3D cine phase-contrast MRI and MR-based computational fluid dynamics

International Nuclear Information System (INIS)

Isoda, Haruo; Sakahara, Harumi; Ohkura, Yasuhide; Kosugi, Takashi; Hirano, Masaya; Alley, Marcus T.; Bammer, Roland; Pelc, Norbert J.; Namba, Hiroki

2010-01-01

Hemodynamics is thought to play a very important role in the initiation, growth, and rupture of intracranial aneurysms. The purpose of our study was to compare hemodynamics of intracranial aneurysms of MR fluid dynamics (MRFD) using 3D cine PC MR imaging (4D-Flow) at 1.5 T and MR-based computational fluid dynamics (CFD). 4D-Flow was performed for five intracranial aneurysms by a 1.5 T MR scanner. 3D TOF MR angiography was performed for geometric information. The blood flow in the aneurysms was modeled using CFD simulation based on the finite element method. We used MR angiographic data as the vascular models and MR flow information as boundary conditions in CFD. 3D velocity vector fields, 3D streamlines, shearing velocity maps, wall shear stress (WSS) distribution maps and oscillatory shear index (OSI) distribution maps were obtained by MRFD and CFD and were compared. There was a moderate to high degree of correlation in 3D velocity vector fields and a low to moderate degree of correlation in WSS of aneurysms between MRFD and CFD using regression analysis. The patterns of 3D streamlines were similar between MRFD and CFD. The small and rotating shearing velocities and higher OSI were observed at the top of the spiral flow in the aneurysms. The pattern and location of shearing velocity in MRFD and CFD were similar. The location of high oscillatory shear index obtained by MRFD was near to that obtained by CFD. MRFD and CFD of intracranial aneurysms correlated fairly well. (orig.)

Cumulative phase delay imaging for contrast-enhanced ultrasound tomography

International Nuclear Information System (INIS)

Demi, Libertario; Van Sloun, Ruud J G; Wijkstra, Hessel; Mischi, Massimo

2015-01-01

Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization. (fast track communication)

Combined mixed approach algorithm for in-line phase-contrast x-ray imaging

International Nuclear Information System (INIS)

De Caro, Liberato; Scattarella, Francesco; Giannini, Cinzia; Tangaro, Sabina; Rigon, Luigi; Longo, Renata; Bellotti, Roberto

2010-01-01

Purpose: In the past decade, phase-contrast imaging (PCI) has been applied to study different kinds of tissues and human body parts, with an increased improvement of the image quality with respect to simple absorption radiography. A technique closely related to PCI is phase-retrieval imaging (PRI). Indeed, PCI is an imaging modality thought to enhance the total contrast of the images through the phase shift introduced by the object (human body part); PRI is a mathematical technique to extract the quantitative phase-shift map from PCI. A new phase-retrieval algorithm for the in-line phase-contrast x-ray imaging is here proposed. Methods: The proposed algorithm is based on a mixed transfer-function and transport-of-intensity approach (MA) and it requires, at most, an initial approximate estimate of the average phase shift introduced by the object as prior knowledge. The accuracy in the initial estimate determines the convergence speed of the algorithm. The proposed algorithm retrieves both the object phase and its complex conjugate in a combined MA (CMA). Results: Although slightly less computationally effective with respect to other mixed-approach algorithms, as two phases have to be retrieved, the results obtained by the CMA on simulated data have shown that the obtained reconstructed phase maps are characterized by particularly low normalized mean square errors. The authors have also tested the CMA on noisy experimental phase-contrast data obtained by a suitable weakly absorbing sample consisting of a grid of submillimetric nylon fibers as well as on a strongly absorbing object made of a 0.03 mm thick lead x-ray resolution star pattern. The CMA has shown a good efficiency in recovering phase information, also in presence of noisy data, characterized by peak-to-peak signal-to-noise ratios down to a few dBs, showing the possibility to enhance with phase radiography the signal-to-noise ratio for features in the submillimetric scale with respect to the attenuation

Geriatría y cine: una mirada desde la salud

OpenAIRE

Beatriz OGANDO DÍAZ

2016-01-01

Envejecer no implica enfermar. La OMS en “Salud y envejecimiento” plantea una visión positiva bajo el concepto de “envejecimiento activo” para superar el papel pasivo que se ha otorgado a las personas mayores. La vejez se acompaña de estereotipos que cambian conforme cambia la sociedad. El cine es un buen vehículo para detectarlos y reflexionar sobre ellos.El cine contribuye a la construcción de la representación social de la mirada sobre la vejez. En las últimas décadas muchas películas han ...

Cine computed tomography for diagnosis of superior vena cava obstruction following the mustard operation

International Nuclear Information System (INIS)

Matherne, G.P.; Atkins, D.L.; Frey, E.E.; Smith, W.L.

1987-01-01

Superior vena caval obstruction is a well described complication following Mustard's repair for transposition of the great arteries. We report a case of a 6-year-old child with superior vena cava obstruction correctly diagnosed by Cine-CT. The advantages of imaging with Cine-CT for this complication are discussed. (orig.)

Regularized iterative integration combined with non-linear diffusion filtering for phase-contrast x-ray computed tomography.

Science.gov (United States)

Burger, Karin; Koehler, Thomas; Chabior, Michael; Allner, Sebastian; Marschner, Mathias; Fehringer, Andreas; Willner, Marian; Pfeiffer, Franz; Noël, Peter

2014-12-29

Phase-contrast x-ray computed tomography has a high potential to become clinically implemented because of its complementarity to conventional absorption-contrast.In this study, we investigate noise-reducing but resolution-preserving analytical reconstruction methods to improve differential phase-contrast imaging. We apply the non-linear Perona-Malik filter on phase-contrast data prior or post filtered backprojected reconstruction. Secondly, the Hilbert kernel is replaced by regularized iterative integration followed by ramp filtered backprojection as used for absorption-contrast imaging. Combining the Perona-Malik filter with this integration algorithm allows to successfully reveal relevant sample features, quantitatively confirmed by significantly increased structural similarity indices and contrast-to-noise ratios. With this concept, phase-contrast imaging can be performed at considerably lower dose.

Consumo de cine-video : Una investigación empírica

OpenAIRE

Wallace, Santiago; Muñoz Cobeñas, Leticia Amelia; Rodríguez, Pablo Gustavo; Silva, Celia; Cabutti, Marcela

1998-01-01

Este trabajo recoge parte de los resultados del proyecto de investigación "Las industrias culturales hoy: consumo de cine-video y su relación con las políticas culturales (La Plata)", realizado durante los años 1994 y 1995 en el marco del Programa de Incentivos. Se intentó, en base a los objetivos propuestos analizar las modalidades de elección y consumo al momento de ver cine en el ámbito hogareño. Facultad de Bellas Artes

Comparison of post contrast CT urography phases in bladder cancer detection

Energy Technology Data Exchange (ETDEWEB)

Helenius, Malin; Dahlman, Par; Lonnemark, Maria; Magnusson, Anders [Uppsala University Hospital, Department of Surgical Sciences, Section of Radiology, Uppsala (Sweden); Brekkan, Einar [Uppsala University Hospital, Department of Surgical Sciences, Section of Urology, Uppsala (Sweden); Wernroth, Lisa [Uppsala University Hospital, Uppsala Clinical Research Center, Uppsala (Sweden)

2016-02-15

The aim of this study was to investigate which post-contrast phase(s) in a four-phase CT urography protocol is (are) most suitable for bladder cancer detection. The medical records of 106 patients with visible haematuria who underwent a CT urography examination, including unenhanced, enhancement-triggered corticomedullary (CMP), nephrographic (NP) and excretory (EP) phases, were reviewed. The post-contrast phases (n = 318 different phases) were randomized into an evaluation order and blindly reviewed by two uroradiologists. Twenty-one patients were diagnosed with bladder cancer. Sensitivity for bladder cancer detection was 0.95 in CMP, 0.83 in NP and 0.81 in EP. Negative predictive value (NPV) was 0.99 in CMP, 0.96 in NP and 0.95 in EP. The sensitivity was higher in CMP than in both NP (p-value 0.016) and EP (p-value 0.0003). NPV was higher in CMP than in NP (p-value 0.024) and EP (p-value 0.002). In the CT urography protocol with enhancement-triggered scan, sensitivity and NPV were highest in the corticomedullary phase, and this phase should be used for bladder assessment. (orig.)

Comparison of post contrast CT urography phases in bladder cancer detection

International Nuclear Information System (INIS)

Helenius, Malin; Dahlman, Par; Lonnemark, Maria; Magnusson, Anders; Brekkan, Einar; Wernroth, Lisa

2016-01-01

The aim of this study was to investigate which post-contrast phase(s) in a four-phase CT urography protocol is (are) most suitable for bladder cancer detection. The medical records of 106 patients with visible haematuria who underwent a CT urography examination, including unenhanced, enhancement-triggered corticomedullary (CMP), nephrographic (NP) and excretory (EP) phases, were reviewed. The post-contrast phases (n = 318 different phases) were randomized into an evaluation order and blindly reviewed by two uroradiologists. Twenty-one patients were diagnosed with bladder cancer. Sensitivity for bladder cancer detection was 0.95 in CMP, 0.83 in NP and 0.81 in EP. Negative predictive value (NPV) was 0.99 in CMP, 0.96 in NP and 0.95 in EP. The sensitivity was higher in CMP than in both NP (p-value 0.016) and EP (p-value 0.0003). NPV was higher in CMP than in NP (p-value 0.024) and EP (p-value 0.002). In the CT urography protocol with enhancement-triggered scan, sensitivity and NPV were highest in the corticomedullary phase, and this phase should be used for bladder assessment. (orig.)

The second-order differential phase contrast and its retrieval for imaging with x-ray Talbot interferometry

International Nuclear Information System (INIS)

Yang Yi; Tang Xiangyang

2012-01-01

Purpose: The x-ray differential phase contrast imaging implemented with the Talbot interferometry has recently been reported to be capable of providing tomographic images corresponding to attenuation-contrast, phase-contrast, and dark-field contrast, simultaneously, from a single set of projection data. The authors believe that, along with small-angle x-ray scattering, the second-order phase derivative Φ ″ s (x) plays a role in the generation of dark-field contrast. In this paper, the authors derive the analytic formulae to characterize the contribution made by the second-order phase derivative to the dark-field contrast (namely, second-order differential phase contrast) and validate them via computer simulation study. By proposing a practical retrieval method, the authors investigate the potential of second-order differential phase contrast imaging for extensive applications. Methods: The theoretical derivation starts at assuming that the refractive index decrement of an object can be decomposed into δ=δ s +δ f , where δ f corresponds to the object's fine structures and manifests itself in the dark-field contrast via small-angle scattering. Based on the paraxial Fresnel-Kirchhoff theory, the analytic formulae to characterize the contribution made by δ s , which corresponds to the object's smooth structures, to the dark-field contrast are derived. Through computer simulation with specially designed numerical phantoms, an x-ray differential phase contrast imaging system implemented with the Talbot interferometry is utilized to evaluate and validate the derived formulae. The same imaging system is also utilized to evaluate and verify the capability of the proposed method to retrieve the second-order differential phase contrast for imaging, as well as its robustness over the dimension of detector cell and the number of steps in grating shifting. Results: Both analytic formulae and computer simulations show that, in addition to small-angle scattering, the

Clinical implementation of x-ray phase-contrast imaging: Theoretical foundations and design considerations

International Nuclear Information System (INIS)

Wu Xizeng; Liu Hong

2003-01-01

Theoretical foundation and design considerations of a clinical feasible x-ray phase contrast imaging technique were presented in this paper. Different from the analysis of imaging phase object with weak absorption in literature, we proposed a new formalism for in-line phase-contrast imaging to analyze the effects of four clinically important factors on the phase contrast. These are the body parts attenuation, the spatial coherence of spherical waves from a finite-size focal spot, and polychromatic x-ray and radiation doses to patients for clinical applications. The theory presented in this paper can be applied widely in diagnostic x-ray imaging procedures. As an example, computer simulations were conducted and optimal design parameters were derived for clinical mammography. The results of phantom experiments were also presented which validated the theoretical analysis and computer simulations

Cine magnetic resonance imaging, computed tomography and ultrasonography in the evaluation of chest wall invasion of lung cancer

International Nuclear Information System (INIS)

Yokozaki, Michiya; Nawano, Shigeru; Nagai, Kanji; Moriyama, Noriyuki; Kodama, Tetsuro; Nishiwaki, Yutaka.

1997-01-01

To assess the usefulness of cine-magnetic resonance imaging (cine-MRI) in the evaluation of chest wall invasion, we compared the results of cine-MRI with those of computed tomography (CT) and ultrasonography (US). Eleven patients were examined who had no pain and who were difficult to diagnose by routine examinations. MRI was performed with a Magnetom SP/4000, 1.5T unit (Siemens, Germany). For cine imaging, continuous turbo-FLUSH (ultra fast low angle shot) images were obtained at an orthogonal section to the chest wall during slow deep breathing. A CT scan was performed using a TCT 900S or Super Helix (Toshiba, Japan) at 1 cm intervals, with section thicknesses of 1 cm throughout the entire chest. US was performed with a model SSA-270A (Toshiba, Japan) with 7.5-MHz linear array scanners (PLF-705S; Toshiba, Japan). Sensitivity, specificity and accuracy were 67%, 75% and 73% for cine MRI, 67%, 63% and 64% for CT, 33%, 75% and 64% for US, respectively. These results indicate that cine MRI is potentially useful for the diagnosis of chest wall invasion of lung cancer. (author)

Grating-based phase contrast tomosynthesis imaging: Proof-of-concept experimental studies

International Nuclear Information System (INIS)

Li, Ke; Ge, Yongshuai; Garrett, John; Bevins, Nicholas; Zambelli, Joseph; Chen, Guang-Hong

2014-01-01

Purpose: This paper concerns the feasibility of x-ray differential phase contrast (DPC) tomosynthesis imaging using a grating-based DPC benchtop experimental system, which is equipped with a commercial digital flat-panel detector and a medical-grade rotating-anode x-ray tube. An extensive system characterization was performed to quantify its imaging performance. Methods: The major components of the benchtop system include a diagnostic x-ray tube with a 1.0 mm nominal focal spot size, a flat-panel detector with 96 μm pixel pitch, a sample stage that rotates within a limited angular span of ±30°, and a Talbot-Lau interferometer with three x-ray gratings. A total of 21 projection views acquired with 3° increments were used to reconstruct three sets of tomosynthetic image volumes, including the conventional absorption contrast tomosynthesis image volume (AC-tomo) reconstructed using the filtered-backprojection (FBP) algorithm with the ramp kernel, the phase contrast tomosynthesis image volume (PC-tomo) reconstructed using FBP with a Hilbert kernel, and the differential phase contrast tomosynthesis image volume (DPC-tomo) reconstructed using the shift-and-add algorithm. Three inhouse physical phantoms containing tissue-surrogate materials were used to characterize the signal linearity, the signal difference-to-noise ratio (SDNR), the three-dimensional noise power spectrum (3D NPS), and the through-plane artifact spread function (ASF). Results: While DPC-tomo highlights edges and interfaces in the image object, PC-tomo removes the differential nature of the DPC projection data and its pixel values are linearly related to the decrement of the real part of the x-ray refractive index. The SDNR values of polyoxymethylene in water and polystyrene in oil are 1.5 and 1.0, respectively, in AC-tomo, and the values were improved to 3.0 and 2.0, respectively, in PC-tomo. PC-tomo and AC-tomo demonstrate equivalent ASF, but their noise characteristics quantified by the 3D NPS

Grating-based phase contrast tomosynthesis imaging: Proof-of-concept experimental studies

Science.gov (United States)

Li, Ke; Ge, Yongshuai; Garrett, John; Bevins, Nicholas; Zambelli, Joseph; Chen, Guang-Hong

2014-01-01

Purpose: This paper concerns the feasibility of x-ray differential phase contrast (DPC) tomosynthesis imaging using a grating-based DPC benchtop experimental system, which is equipped with a commercial digital flat-panel detector and a medical-grade rotating-anode x-ray tube. An extensive system characterization was performed to quantify its imaging performance. Methods: The major components of the benchtop system include a diagnostic x-ray tube with a 1.0 mm nominal focal spot size, a flat-panel detector with 96 μm pixel pitch, a sample stage that rotates within a limited angular span of ±30°, and a Talbot-Lau interferometer with three x-ray gratings. A total of 21 projection views acquired with 3° increments were used to reconstruct three sets of tomosynthetic image volumes, including the conventional absorption contrast tomosynthesis image volume (AC-tomo) reconstructed using the filtered-backprojection (FBP) algorithm with the ramp kernel, the phase contrast tomosynthesis image volume (PC-tomo) reconstructed using FBP with a Hilbert kernel, and the differential phase contrast tomosynthesis image volume (DPC-tomo) reconstructed using the shift-and-add algorithm. Three inhouse physical phantoms containing tissue-surrogate materials were used to characterize the signal linearity, the signal difference-to-noise ratio (SDNR), the three-dimensional noise power spectrum (3D NPS), and the through-plane artifact spread function (ASF). Results: While DPC-tomo highlights edges and interfaces in the image object, PC-tomo removes the differential nature of the DPC projection data and its pixel values are linearly related to the decrement of the real part of the x-ray refractive index. The SDNR values of polyoxymethylene in water and polystyrene in oil are 1.5 and 1.0, respectively, in AC-tomo, and the values were improved to 3.0 and 2.0, respectively, in PC-tomo. PC-tomo and AC-tomo demonstrate equivalent ASF, but their noise characteristics quantified by the 3D NPS

Bienvenido Mister Cine a la enseñanza de las ciencias

Directory of Open Access Journals (Sweden)

Francisco José García Borrás

2009-01-01

Full Text Available El profesor de ciencias tiene al alcance de su mano una base de datos increíble, el cine. De este recurso se puede extraer gran cantidad de información. A través de este escrito se procura mostrar como el cine se puede considerar un medio realmente inestimable en la creación de prácticas educativas que fomentan el proceso deenseñanza-aprendizaje, tales como la crítica, la observación, la reflexión e incluso la investigación.

Non-destructive characterisation of polymers and Al-alloys by polychromatic cone-beam phase contrast tomography

International Nuclear Information System (INIS)

Kastner, Johann; Plank, Bernhard; Requena, Guillermo

2012-01-01

X-ray computed tomography (XCT) has become a very important tool for the non-destructive characterisation of materials. Continuous improvements in the quality and performance of X-ray tubes and detectors have led to cone-beam XCT systems that can now achieve spatial resolutions down to 1 μm and even below. Since not only the amplitude but also the phase of an X-ray beam is altered while passing through an object, phase contrast effects can occur even for polychromatic sources when the spatial coherence due to a small focal spot size is high enough. This can lead to significant improvements over conventional attenuation-based X-ray computed tomography. Phase contrast can increase by edge enhancement the visibility of small structures and of features which are only slightly different in attenuation. We report on the possibilities of polychromatic cone-beam phase contrast tomography for non-destructive characterisation of materials. A carbon fibre-reinforced polymer and the Al-alloys AlMg5Si7 and AlSi18 were investigated with high resolution cone-beam X-ray computed tomography with a polychromatic tube source. Under certain conditions strong phase contrast resulting in an upward and downward overshooting of the grey values across edges was observed. The phase effects are much stronger for the polymer than for the Al-alloys. The influence on the phase contrast of the parameters, including source-detector distance, focal spot size and tube acceleration voltage is presented. Maximum phase contrast was observed for a maximum distance between the source and the detector, for a low voltage and a minimum focal spot size at the X-ray source. The detectability of the different phases is improved by the edge enhancement and the resulting improvement of sharpness. Thus, a better segmentation of the carbon fibres in the fibre-reinforced polymer and of the Mg 2 Si-phase in the AlMg5Si7-alloy is achieved. Primary and eutectic Si cannot be detected by attenuation-based X

Reconfiguración de flujos en el circuito internacional de festivales: el programa "Cine en construcción" / Flows Reconfiguration in the International Film Festival Circuit: The Program «Cine en Construcció»

Directory of Open Access Journals (Sweden)

Minerva Campos

2016-08-01

Full Text Available En el contexto de programas de financiación destinados a determinados cines periféricos y/o minoritarios creados por los festivales de cine y fundaciones asociadas a ellos, este artículo se centra en el programa «Cine en Construcción»: una iniciativa conjunta del Festival Internacional de Cine de San Sebastián y los Rencontres Cinémas d’Amérique Latine de Toulouse creada en 2002 y destinada a la finalización de proyectos latinoamericanos. El artículo se interesa por cómo este tipo de operaciones pueden beneficiar a los festivales de cine impulsores en relación a su visibilidad en el circuito internacional. Al igual que los festivales se articulan en forma de red y tienen un calendario propio a lo largo del año, parece ser que estos fondos de ayuda se están estructurando de la misma forma. De igual manera, la itinerancia posterior en el circuito de festivales, salas comerciales o pantallas alternativas de las películas auspiciadas por estas iniciativas contribuiría a la visibilidad de los festivales impulsores, así como a una definición quizá más precisa del tipo de cine en el que está interesado el evento: ya que en casos como «Cine en Construcción» no solo se financian determinadas películas sino también la mayoría de las veces los festivales de San Sebastián y Toulouse las programan una vez finalizadas (ya sea en las secciones oficiales competitivas o en programas paralelos.Palabras clave: circuito de festivales de cine, fondos de financiación cinematográficos, itinerancia, estrategias de visibilidad, cines periféricos.AbstractIn the context of fund programs created by film festivals and associated foundations to finance some peripheral and/or minority cinemas, this article focuses on the program «Cine en Construcción» (‘Cinema under Construction’: a joint initiative created by San Sebastián International Film Festival and the Rencontres Cinémas d’Amérique Latine de Toulouse in 2002 destined to the

Phase-contrast enhanced mammography: A new diagnostic tool for breast imaging

International Nuclear Information System (INIS)

Wang Zhentian; Thuering, Thomas; David, Christian; Roessl, Ewald; Trippel, Mafalda; Kubik-Huch, Rahel A.; Singer, Gad; Hohl, Michael K.; Hauser, Nik; Stampanoni, Marco

2012-01-01

Phase contrast and scattering-based X-ray imaging can potentially revolutionize the radiological approach to breast imaging by providing additional and complementary information to conventional, absorption-based methods. We investigated native, non-fixed whole breast samples using a grating interferometer with an X-ray tube-based configuration. Our approach simultaneously recorded absorption, differential phase contrast and small-angle scattering signals. The results show that this novel technique - combined with a dedicated image fusion algorithm - has the potential to deliver enhanced breast imaging with complementary information for an improved diagnostic process.

Phase-contrast enhanced mammography: A new diagnostic tool for breast imaging

Energy Technology Data Exchange (ETDEWEB)

Wang Zhentian; Thuering, Thomas; David, Christian; Roessl, Ewald; Trippel, Mafalda; Kubik-Huch, Rahel A.; Singer, Gad; Hohl, Michael K.; Hauser, Nik; Stampanoni, Marco [Swiss Light Source, Paul Scherrer Institut, 5232 Villigen (Switzerland); Laboratory for Micro and Nanotechnology, Paul Scherrer Institut, 5232 Villigen (Switzerland); Philips Technologie GmbH, Roentgenstrasse 24, 22335 Hamburg (Germany); Institute of Pathology, Kantonsspital Baden, 5404 Baden (Switzerland); Department of Radiology, Kantonsspital Baden, 5404 Baden (Switzerland); Institute of Pathology, Kantonsspital Baden, 5404 Baden (Switzerland); Department of Gynecology and Obstetrics, Interdisciplinary Breast Center Baden, Kantonsspital Baden, 5404 Baden (Switzerland); Swiss Light Source, Paul Scherrer Institut, 5232 Villigen, Switzerland and Institute for Biomedical Engineering, University and ETH Zuerich, 8092 Zuerich (Switzerland)

2012-07-31

Phase contrast and scattering-based X-ray imaging can potentially revolutionize the radiological approach to breast imaging by providing additional and complementary information to conventional, absorption-based methods. We investigated native, non-fixed whole breast samples using a grating interferometer with an X-ray tube-based configuration. Our approach simultaneously recorded absorption, differential phase contrast and small-angle scattering signals. The results show that this novel technique - combined with a dedicated image fusion algorithm - has the potential to deliver enhanced breast imaging with complementary information for an improved diagnostic process.

Cine, literatura y mito: Don Quijote en el cine, más allá de la adaptación

Directory of Open Access Journals (Sweden)

Pardo García, Pedro Javier

2011-04-01

Full Text Available This paper discusses Don Quixote’s presence in film, but in terms of the myth rather than the book, an approach which goes beyond adaptation and opens up the field of study in a significant way. In so doing it proposes a tentative but coherent description of the quixotic myth or narrative pattern as that of the inadequate and romantic imitator/reader of fiction, which is the point of departure for the elaboration of an initial corpus of quixotic movies. The protagonists of these films are frustrated imitators of cinematographic models, female Quixotes who romanticize reality and heroes who are Quixotic because they are not fit for the heroic task they have undertaken. In order to illustrate this deep penetration of the myth into the cinematic medium, a recent example in Spanish cinema will be examined, The Heart of the Warrior (El corazón del guerrero, 2000, a film directed by Daniel Monzón, where these several varieties are at work in a combined and crystal clear way. Our survey will allow us to make a series of distinctions which organise and structure the different kinds of relationship between Don Quixote and film (Cervantean, quixotic and quixotish film and, finally, to draw a series of theoretical conclusions which can be applied to the comparative study of film and literature.

Este trabajo se ocupa de la presencia en el cine de Don Quijote, pero no del libro sino del mito, una perspectiva que va mucho más allá de la adaptación y abre considerablemente el campo de estudio. Para ello, se propone una descripción que se sabe provisional pero intenta ser rigurosa del mito o el patrón narrativo quijotesco como el del lector/imitador romántico e inadecuado de ficción, a partir de la cual se puede elaborar un primer corpus de películas quijotescas. En él se incluyen las protagonizadas por imitadores fallidos de modelos cinematográficos, por Quijotes femeninos que romantizan la realidad y por diversos tipos de héroes que son

Standardized cine-loop documentation in abdominal ultrasound facilitates offline image interpretation.

Science.gov (United States)

Dormagen, Johann Baptist; Gaarder, Mario; Drolsum, Anders

2015-01-01

One of the main disadvantages of conventional ultrasound is its operator dependency, which might impede the reproducibility of the sonographic findings. A new approach with cine-loops and standardized scan protocols can overcome this drawback. To compare abdominal ultrasound findings of immediate bedside reading by performing radiologist with offline reading by a non-performing radiologist, using standardized cine-loop sequences. Over a 6-month period, three radiologists performed 140 dynamic ultrasound organ-based examinations in 43 consecutive outpatients. Examination protocols were standardized and included predefined probe position and sequences of short cine-loops of the liver, gallbladder, pancreas, kidneys, and urine bladder, covering the organs completely in two planes. After bedside examinations, the studies were reviewed and read out immediately by the performing radiologist. Image quality was registered from 1 (no diagnostic value) to 5 (excellent cine-loop quality). Offline reading was performed blinded by a radiologist who had not performed the examination. Bedside and offline reading were compared with each other and with consensus results. In 140 examinations, consensus reading revealed 21 cases with renal disorders, 17 cases with liver and bile pathology, and four cases with bladder pathology. Overall inter-observer agreement was 0.73 (95% CI 0.61-0.91), with lowest agreement for findings of the urine bladder (0.36) and highest agreement in liver examinations (0.90). Disagreements between the two readings were seen in nine kidneys, three bladder examinations, one pancreas and bile system examinations each, and in one liver, giving a total number of mismatches of 11%. Nearly all cases of mismatch were of minor clinical significance. The median image quality was 3 (range, 2-5) with most examinations deemed a quality of 3. Compared to consensus reading, overall accuracy was 96% for bedside reading and 94% for offline reading. Standardized cine

Tracheomalacia in adults with cystic fibrosis: determination of prevalence and severity with dynamic cine CT.

LENUS (Irish Health Repository)

McDermott, Shaunagh

2012-02-01

PURPOSE: To determine the prevalence and severity of tracheomalacia in adults with cystic fibrosis (CF) by using dynamic cine multidetector computed tomography (CT) and to correlate these findings with pulmonary function test (PFT) results and the severity of parenchymal lung disease. MATERIALS AND METHODS: In this institutional review board-approved HIPAA-compliant study, 40 patients with CF (22 men, 18 women; mean age, 28 years +\\/- 8 [standard deviation]; age range, 18-54 years) prospectively underwent PFTs, standard thin-section CT, and two dynamic cine multidetector CT acquisitions. Ten control subjects underwent dynamic cine multidetector CT. After standard thin-section CT was completed, dynamic cine multidetector CT was performed during a forced expiratory maneuver and during coughing. Dynamic cine multidetector CT images in nine patients were excluded. Maximal inspiratory, dynamic expiratory, and end-expiratory tracheal luminal areas were compared (Student t test) and correlated (Spearman rank) with PFT results and severity of parenchymal lung disease. RESULTS: Mean predicted forced expiratory volume in 1 second (FEV(1)) was 70.6% +\\/- 20.7, and mean Bhalla CT score was 41.8% +\\/- 13.6. In patients with CF, dynamic cine mean tracheal cross-sectional area reduction was 51.7% +\\/- 18.4 (range, 9%-89%) for forced expiratory maneuvers and 68.8% +\\/- 11.7 (range, 18%-88%) for coughing (P = .001). Tracheomalacia was demonstrated in 24 (69%) patients and no control subjects during forced expiratory maneuvers (P = .001) and in 10 (29%) patients and one (10%) control subject during coughing. For end-expiration images, mean tracheal luminal reduction was 16.1% +\\/- 14.0% (range, 0.0%-53.0%), with one patient demonstrating tracheal luminal reduction of more than 50%. There was no correlation between tracheal cross-sectional luminal reduction and either predicted FEV(1) or CT Bhalla score. CONCLUSION: Tracheomalacia depicted at dynamic cine multidetector CT is a

Estimation of visibility of phase contrast with extraction voltages for field emission gun electron microscopes

Energy Technology Data Exchange (ETDEWEB)

Meng, Xing, E-mail: xmeng101@gmail.com

2017-02-15

Estimation was made for visibility of phase contrast with varying extraction voltages. The resulting decay rates of visibility show that images with low image contrast from cryo EM will be seriously impacted with high extraction voltages. - Highlights: • Cryo EM • Phase contrast • Extraction votage.

Cine y vanguardias artística: conflictos, encuentros, fronteras [Prólogo e introducción

OpenAIRE

Sánchez-Biosca, Vicente

2004-01-01

El cine y la vanguardia estaban condenados a encontrarse. Ambos fueron producto del paso del siglo XIX al XX; ambos ambicionaban rupturas y creían ser el punto de partida de una nueva era. Sin embargo, los encuentros no fueron inmediatos y sobre todo, el cine se aventuró pronto en caminos comerciales y narrativos ajenos, incluso opuestos, a los de la vanguardia. Así la condición vanguardiasta del cine plantea desde sus mismos orígenes problemas de definición que no han preocupado tanto a los ...

Low dose reconstruction algorithm for differential phase contrast imaging.

Science.gov (United States)

Wang, Zhentian; Huang, Zhifeng; Zhang, Li; Chen, Zhiqiang; Kang, Kejun; Yin, Hongxia; Wang, Zhenchang; Marco, Stampanoni

2011-01-01

Differential phase contrast imaging computed tomography (DPCI-CT) is a novel x-ray inspection method to reconstruct the distribution of refraction index rather than the attenuation coefficient in weakly absorbing samples. In this paper, we propose an iterative reconstruction algorithm for DPCI-CT which benefits from the new compressed sensing theory. We first realize a differential algebraic reconstruction technique (DART) by discretizing the projection process of the differential phase contrast imaging into a linear partial derivative matrix. In this way the compressed sensing reconstruction problem of DPCI reconstruction can be transformed to a resolved problem in the transmission imaging CT. Our algorithm has the potential to reconstruct the refraction index distribution of the sample from highly undersampled projection data. Thus it can significantly reduce the dose and inspection time. The proposed algorithm has been validated by numerical simulations and actual experiments.

Compressed sensing reconstruction of cardiac cine MRI using golden angle spiral trajectories.

Science.gov (United States)

Tolouee, Azar; Alirezaie, Javad; Babyn, Paul

2015-11-01

In dynamic cardiac cine Magnetic Resonance Imaging (MRI), the spatiotemporal resolution is limited by the low imaging speed. Compressed sensing (CS) theory has been applied to improve the imaging speed and thus the spatiotemporal resolution. The purpose of this paper is to improve CS reconstruction of under sampled data by exploiting spatiotemporal sparsity and efficient spiral trajectories. We extend k-t sparse algorithm to spiral trajectories to achieve high spatio temporal resolutions in cardiac cine imaging. We have exploited spatiotemporal sparsity of cardiac cine MRI by applying a 2D+time wavelet-Fourier transform. For efficient coverage of k-space, we have used a modified version of multi shot (interleaved) spirals trajectories. In order to reduce incoherent aliasing artifact, we use different random undersampling pattern for each temporal frame. Finally, we have used nonuniform fast Fourier transform (NUFFT) algorithm to reconstruct the image from the non-uniformly acquired samples. The proposed approach was tested in simulated and cardiac cine MRI data. Results show that higher acceleration factors with improved image quality can be obtained with the proposed approach in comparison to the existing state-of-the-art method. The flexibility of the introduced method should allow it to be used not only for the challenging case of cardiac imaging, but also for other patient motion where the patient moves or breathes during acquisition. Copyright © 2015 Elsevier Inc. All rights reserved.

X-ray imaging with monochromatic synchrotron radiation. Fluorescent and phase-contrast method

Energy Technology Data Exchange (ETDEWEB)

Takeda, Tohoru; Itai, Yuji [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine

2002-05-01

To obtain the high sensitive x-ray images of biomedical object, new x-ray imaging techniques using fluorescent x-ray and phase-contrast x-ray are being developed in Japan. Fluorescent x-ray CT can detect very small amounts of specific elements in the order of ppm at one pixel, whereas phase-contrast x-ray imaging with interferometer can detect minute differences of biological object. Here, our recent experimental results are presented. (author)

2D XD-GRASP provides better image quality than conventional 2D cardiac cine MRI for patients who cannot suspend respiration

Science.gov (United States)

Piekarski, Eve; Chitiboi, Teodora; Ramb, Rebecca; Latson, Larry A; Bhatla, Puneet; Feng, Li; Axel, Leon

2017-01-01

Object Residual respiratory motion degrades image quality in conventional cardiac cine MRI (CCMR). We evaluated whether a free-breathing (FB) radial imaging CCMR sequence with compressed sensing reconstruction (eXtra-Dimension (e.g. cardiac and respiratory phases) Golden-angle RAdial Sparse Parallel, or XD-GRASP) could provide better image quality than a conventional Cartesian breath-held (BH) sequence, in an unselected population of patients undergoing clinical CCMR. Material and Methods 101 patients who underwent BH and FB imaging in a mid-ventricular short-axis plane at a matching location were included. Visual and quantitative image analysis was performed by two blinded experienced readers, using a 5-point qualitative scale to score overall image quality and visual signal-to-noise ratio (SNR) grade, with measures of noise and sharpness. End-diastole (ED) and end-systole (ES) left-ventricular areas were also measured and compared for both BH and FB images. Results Image quality was generally better with the BH cines (overall quality grade BH vs FB: 4 vs 2.9, pXD-GRASP CCMR was visually inferior to conventional BH cardiac cine in general, it provided improved image quality in the subgroup of patients presenting respiratory motion-induced artifacts on breath-held images. PMID:29067539

Evaluation on correction factor for in-line X-ray phase contrast computed tomography

Energy Technology Data Exchange (ETDEWEB)

Jin, Mingli; Huang, Zhifeng; Zhang, Li; Zhang, Ran [Tsinghua Univ., Beijing (China). Dept. of Engineering Physics; Ministry of Education, Beijing (China). Key Laboratory of Particle and Radiation Imaging; Yin, Hongxia; Liu, Yunfu; Wang, Zhenchang [Capital Medical Univ., Beijing (China). Medical Imaging Center; Xiao, Tiqiao [Chinese Academy of Sciences, Shanghai (China). Shanghai Inst. of Applied Physics

2011-07-01

X-ray in-line phase contrast computed tomography (CT) is an effective nondestructive tool, providing 3D distribution of the refractive index of weakly absorbing low-Z object with high resolution and image contrast, especially with high-brilliance third-generation synchrotron radiation sources. Modified Bronnikov's algorithm (MBA), one of the in-line phase contrast CT reconstruction algorithms, can reconstruct the refractive index distribution of a pure phase object with a single computed tomographic data set. The key idea of the MBA is to use a correction factor in the filter function to stabilize the behavior at low frequencies. In this paper, we evaluate the influences of the correction factor to the final reconstruction results of the absorption-phase-mixed objects with analytical simulation and actual experiments. The limitations of the MBA are discussed finally. (orig.)

Value of Cine-MRI sequences before and after injection in the diagnosis of acute myocarditis.

Science.gov (United States)

Zidi, Asma; Zairi, Ihsen; Mzoughi, Khadija; Zakhama, Lilia; Kamoun, Ikram; Ben Halima, Afef; Ridene, Imen

2016-11-01

Cardiovascular magnetic resonance (CMR) has become the examination of choice in case of suspicion of acute myocarditis. Late gadolinium enhancement (LGE) imaging is very important to establish this diagnosis. Cine MRI sequences are useful for the study of the myocardial contractility.   The purpose is to estimate the value of cine MRI sequences before and after injection for the diagnosis of acute myocarditis compared with late gadolinium enhanced sequences. We prospectively included 40 patients having a high suspicion of acute myocarditis and examined using a 1.5 Tesla CMR. Cine MRI sequences before and after injection were performed. The protocol also include  T2-weighted  short- tau-inversion-recovery (STIR T2) fast spin echo MRI and LGE imaging eight minutes after injection with visual adjustment of inversion time. Delayed enhancement was found among 23 patients. Fifteen patients (65 %) presented a spontaneous hyper signal detected visually on Cine MRI sequences before injection and 11 patients (48 %) on STIR T2. The hyper signal on Cine MRI sequences after injection of gadolinium was the same topography that the late raising at 23 patients. In addition, we highlighted a significant difference between this hyper signal before injection and the left ventricle ejection fraction (p=0.022) as well as with the telesystolic volume of the left ventricle (LV) indexed by the body mass (p=0.039). Our study suggests that Cine MRI sequences after injection are of equal performance in the diagnosis of acute myocarditis as the LGE sequences and its contibution is important when we want to shorten the examination or when inversion time isn't optimal.

Quantitative evaluation of a single-distance phase-retrieval method applied on in-line phase-contrast images of a mouse lung

International Nuclear Information System (INIS)

Mohammadi, Sara; Larsson, Emanuel; Alves, Frauke; Dal Monego, Simeone; Biffi, Stefania; Garrovo, Chiara; Lorenzon, Andrea; Tromba, Giuliana; Dullin, Christian

2014-01-01

Quantitative analysis concerning the application of a single-distance phase-retrieval algorithm on in-line phase-contrast images of a mouse lung at different sample-to-detector distances is presented. Propagation-based X-ray phase-contrast computed tomography (PBI) has already proven its potential in a great variety of soft-tissue-related applications including lung imaging. However, the strong edge enhancement, caused by the phase effects, often hampers image segmentation and therefore the quantitative analysis of data sets. Here, the benefits of applying single-distance phase retrieval prior to the three-dimensional reconstruction (PhR) are discussed and quantified compared with three-dimensional reconstructions of conventional PBI data sets in terms of contrast-to-noise ratio (CNR) and preservation of image features. The PhR data sets show more than a tenfold higher CNR and only minor blurring of the edges when compared with PBI in a predominately absorption-based set-up. Accordingly, phase retrieval increases the sensitivity and provides more functionality in computed tomography imaging

Trial on MR portal blood flow measurement with phase contrast technique

International Nuclear Information System (INIS)

Tsunoda, Masatoshi; Kimoto, Shin; Togami, Izumi

1991-01-01

Portal blood flow measurement is considered to be important for the analysis of hemodynamics in various liver diseases. The Doppler ultrasound method has been used extensively during the past several years for measuring portal blood flow, as a non-invasive method. However, the Doppler ultrasound technique do not allow the portal blood flow to be measured in cases of obesity, with much intestinal gas, and so on. In this study, we attempted to measure the blood flow in the main trunk of portal vein as an application of MR phase contrast technique to the abdominal region. In the flow phantom study, the flow volumes and the velocities measured by phase contrast technique showed a close correlation with those measured by electromagnetic flowmeter. In the clinical study with 10 healthy volunteers, various values of portal blood flow were obtained. Mean portal blood flow could be measured within the measuring time (about 8 minutes) under natural breathing conditions. Phase contrast technique is considered to be useful for the non-invasive measurement of portal blood flow. (author)

La mujer española y el cine español

Directory of Open Access Journals (Sweden)

Dolores Barbazán Capeáns

2010-01-01

Full Text Available El cine es un elemento motivador para el aprendizaje de español como lengua extranjera, así como un recurso didáctico esencial (Romea 2003, Brandimonte 2003.Con el uso del cine en clase de lenguas se les introducen a los estudiantes contenidos culturales, sociales y económicos (Herrero 2008. El objetivo de este trabajo es la presentación de una unidad didáctica sobre las mujeres españolas y el cine español,dirigida a estudiantes chinos en un contexto de inmersión en Tarragona. Los estudiantes tienen un nivel B2 siguiendo el Marco Común Europeo de Referencia: enseñanza,aprendizaje y evaluación (MCER 2002. Se sigue un enfoque comunicativo por tareas.La duración de la unidad didáctica es de aproximadamente cuatro horas y media. Su aplicación en el aula ha resultado enriquecedora y contó con muy buena acogida por parte de los estudiantes.

Optimization of X-ray phase-contrast imaging based on in-line holography

International Nuclear Information System (INIS)

Wu Xizeng; Liu Hong; Yan Aimin

2005-01-01

This paper introduces a newly conceived formalism for clinical in-line phase-contrast X-ray imaging. The new formalism applies not only to ideal 'thin' objects analyzed in previous studies, but also applies to the real-world tissues used in actual clinical practice. Moreover we have identified the four clinically important factors that affect phase-contrast characteristics. These factors are: (1) body part attenuation (2) the spatial coherence of incident X-rays from an X-ray tube (3) the polychromatic nature of the X-ray source and (4) radiation dose to patients for clinical applications. Techniques of phase image-reconstruction based on the new X-ray in-line holography theory are discussed. Numerical simulations are described which were used to validate the theory. The design parameters of an optimal clinical phase-contrast mammographic imaging system which were determined based on the new theory, and validated in the simulations, are presented. The theory, image reconstruction algorithms, and numerical simulation techniques presented in this paper can be applied widely to clinical diagnostic X-ray imaging applications

MR phase imaging and cerebrospinal fluid flow in the head and spine

International Nuclear Information System (INIS)

Levy, L.M.; Di Chiro, G.

1990-01-01

Motion of the cerebrospinal fluid (CSF) in and around the brain spinal cord was examined in healthy subjects and in a number of patients with abnormalities of the CSF circulation. The pulsatile motion of the CSF was determined by spin echo phase (velocity) imaging, sometimes in combination with gradient echo phase contrast cine. Differences in flow patterns across CSF spaces were observed: Flow reversal in the cerebellomedullary cistern and lumbar area relative to cervical CSF, and in the posterior versus the anterior subarachnoid space in the spinal canal. Flow communication was demonstrated in known communicating cysts or cavities. Differences in flow were also noted across spinal narrowing or block, and across the walls of a variety of cystic lesions in the brain and spinal cord. MR phase imaging of CSF flow provides pathophysiological information of potential clinical importance for the assessment of diseases affecting the CSF circulation. (orig.)

High-throughput, high-resolution X-ray phase contrast tomographic microscopy for visualisation of soft tissue

Energy Technology Data Exchange (ETDEWEB)

McDonald, S A; Marone, F; Hintermueller, C; Stampanoni, M [Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Bensadoun, J-C; Aebischer, P, E-mail: samuel.mcdonald@psi.c [EPFL, School of Life Sciences, Station 15, 1015 Lausanne (Switzerland)

2009-09-01

The use of conventional absorption based X-ray microtomography can become limited for samples showing only very weak absorption contrast. However, a wide range of samples studied in biology and materials science can produce significant phase shifts of the X-ray beam, and thus the use of the phase signal can provide substantially increased contrast and therefore new and otherwise inaccessible information. The application of two approaches for high-throughput, high-resolution X-ray phase contrast tomography, both available on the TOMCAT beamline of the SLS, is illustrated. Differential Phase Contrast (DPC) imaging uses a grating interferometer and a phase-stepping technique. It has been integrated into the beamline environment on TOMCAT in terms of the fast acquisition and reconstruction of data and the availability to scan samples within an aqueous environment. The second phase contrast approach is a modified transfer of intensity approach that can yield the 3D distribution of the phase (refractive index) of a weakly absorbing object from a single tomographic dataset. These methods are being used for the evaluation of cell integrity in 3D, with the specific aim of following and analyzing progressive cell degeneration to increase knowledge of the mechanistic events of neurodegenerative disorders such as Parkinson's disease.

Real-time cardiac magnetic resonance cine imaging with sparse sampling and iterative reconstruction for left-ventricular measures: Comparison with gold-standard segmented steady-state free precession.

Science.gov (United States)

Camargo, Gabriel C; Erthal, Fernanda; Sabioni, Leticia; Penna, Filipe; Strecker, Ralph; Schmidt, Michaela; Zenge, Michael O; Lima, Ronaldo de S L; Gottlieb, Ilan

2017-05-01

Segmented cine imaging with a steady-state free-precession sequence (Cine-SSFP) is currently the gold standard technique for measuring ventricular volumes and mass, but due to multi breath-hold (BH) requirements, it is prone to misalignment of consecutive slices, time consuming and dependent on respiratory capacity. Real-time cine avoids those limitations, but poor spatial and temporal resolution of conventional sequences has prevented its routine application. We sought to examine the accuracy and feasibility of a newly developed real-time sequence with aggressive under-sampling of k-space using sparse sampling and iterative reconstruction (Cine-RT). Stacks of short-axis cines were acquired covering both ventricles in a 1.5T system using gold standard Cine-SSFP and Cine-RT. Acquisition parameters for Cine-SSFP were: acquisition matrix of 224×196, temporal resolution of 39ms, retrospective gating, with an average of 8 heartbeats per slice and 1-2 slices/BH. For Cine-RT: acquisition matrix of 224×196, sparse sampling net acceleration factor of 11.3, temporal resolution of 41ms, prospective gating, real-time acquisition of 1 heart-beat/slice and all slices in one BH. LV contours were drawn at end diastole and systole to derive LV volumes and mass. Forty-one consecutive patients (15 male; 41±17years) in sinus rhythm were successfully included. All images from Cine-SSFP and Cine-RT were considered to have excellent quality. Cine-RT-derived LV volumes and mass were slightly underestimated but strongly correlated with gold standard Cine-SSFP. Inter- and intra-observer analysis presented similar results between both sequences. Cine-RT featuring sparse sampling and iterative reconstruction can achieve spatial and temporal resolution equivalent to Cine-SSFP, providing excellent image quality, with similar precision measurements and highly correlated and only slightly underestimated volume and mass values. Copyright © 2017 Elsevier Inc. All rights reserved.

Strain analysis in CRT candidates using the novel segment length in cine (SLICE) post-processing technique on standard CMR cine images

NARCIS (Netherlands)

Zweerink, A.; Allaart, C.P.; Kuijer, J.P.A.; Wu, L.; Beek, A.M.; Ven, P.M. van de; Meine, M.; Croisille, P.; Clarysse, P.; Rossum, A.C. van; Nijveldt, R.

2017-01-01

OBJECTIVES: Although myocardial strain analysis is a potential tool to improve patient selection for cardiac resynchronization therapy (CRT), there is currently no validated clinical approach to derive segmental strains. We evaluated the novel segment length in cine (SLICE) technique to derive

UN CINEASTA CHILENO. KUZMANICH Y EL CINE DE LA VIOLENCIA EN COLOMBIA

Directory of Open Access Journals (Sweden)

Angélica María Mateus Mora

2007-07-01

Full Text Available La autora presenta un análisis del film Canaguaro (1981 del chileno Dunav Kuzmanich.Se trata de una realización cinematográfica colombiana profundamenteinnovadora en su constitución, en cuanto desarrolla una construcción colectiva e imaginaria de la violencia. En este contexto de la violencia sociopolítica de la guerrilla, el protagonista no es necesariamente un personaje, sino que es el pueblo, algo que es interesante pues conecta el cine latinoamericano con una larga reflexión ensayística. Este film, muestra un cine que asume una posición crítica frente a la historia colombiana oficial, con la clara intención de develar episodios ocultos de esta historia, en especial de una etapa particular, donde el cine logra, incluso más que la misma historiografía, representar la complejidad histórica, analizar los procesos internos y proyectar esa realidad histórica al presente.

Higher resolution cine imaging with compressed sensing for accelerated clinical left ventricular evaluation.

Science.gov (United States)

Lin, Aaron C W; Strugnell, Wendy; Riley, Robyn; Schmitt, Benjamin; Zenge, Michael; Schmidt, Michaela; Morris, Norman R; Hamilton-Craig, Christian

2017-06-01

To assess the clinical feasibility of a compressed sensing cine magnetic resonance imaging (MRI) sequence of both high temporal and spatial resolution (CS_bSSFP) in comparison to a balanced steady-state free precession cine (bSSFP) sequence for reliable quantification of left ventricular (LV) volumes and mass. Segmented MRI cine images were acquired on a 1.5T scanner in 50 patients in the LV short-axis stack orientation using a retrospectively gated conventional bSSFP sequence (generalized autocalibrating partially parallel acquisition [GRAPPA] acceleration factor 2), followed by a prospectively triggered CS_bSSFP sequence with net acceleration factor of 8. Image quality was assessed by published criteria. Comparison of sequences was made in LV volumes and mass, image quality score, quantitative regional myocardial wall motion, and imaging time using Pearson's correlation, Bland-Altman and paired 2-tailed Student's t-test. Differences (bSSFP minus CS_bSSFP, mean ± SD) and Pearson's correlations were 14.8 ± 16.3 (P = 0.31) and r = 0.98 (P cine CS_bSSFP accurately and reliably quantitates LV volumes and mass, shortens acquisition times, and is clinically feasible. 1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;45:1693-1699. © 2016 International Society for Magnetic Resonance in Medicine.

Assessment of Bladder Motion for Clinical Radiotherapy Practice Using Cine-Magnetic Resonance Imaging

International Nuclear Information System (INIS)

McBain, Catherine A.; Khoo, Vincent S.; Buckley, David L.; Sykes, Jonathan S.; Green, Melanie M.; Cowan, Richard A.; Hutchinson, Charles E.; Moore, Christopher J.; Price, Patricia M.

2009-01-01

Purpose: Organ motion is recognized as the principal source of inaccuracy in bladder radiotherapy (RT), but there is currently little information on intrafraction bladder motion. Methods and Materials: We used cine-magnetic resonance imaging (cine-MRI) to study bladder motion relevant to intrafraction RT delivery. On two occasions, a 28 minute cine-MRI sequence was acquired from 10 bladder cancer patients and 5 control participants immediately after bladder emptying, after abstinence from drinking for the preceding hour. From the resulting cine sequences, bladder motion was subjectively assessed. To quantify bladder motion, the bladder was contoured in imaging volume sets at 0, 14, and 28 min to measure changes to bladder volumes, wall displacements, and center of gravity (COG) over time. Results: The dominant source of bladder motion during imaging was bladder filling (up to 101% volume increase); rectal and small bowel movements were transient, with minimal impact. Bladder volume changes were similar for all participants. However for bladder cancer patients, wall displacements were larger (up to 58 mm), less symmetrical, and more variable compared with nondiseased control bladders. Conclusions: Significant and individualized intrafraction bladder wall displacements may occur during bladder RT delivery. This important source of inaccuracy should be incorporated into treatment planning and verification.

Evaluation of mitral regurgitation by cine magnetic resonance imaging

International Nuclear Information System (INIS)

Kobayashi, Shiro; Kishi, Naohiro; Kumai, Toshihiko

1993-01-01

Valvular regurgitation can be detected as a region of signal loss ('flow void') by cardiac cine magnetic resonance (MR) imaging. Cine MR images of 36 patients with mitral regurgitation caused by mitral valve prolapse (MVP) and non-MVP were evaluated and compared with color Doppler flow images. The direction, distance, area and timing of flow void were detected in all patients in several different planes at mitral level with a 0.5 Tesla superconducting magnet by an ECG-gated fast field echo technique. In 23 of the 36 patients contiguous multiple transaxial images were also obtained to calculate the volumes of flow void and the left atrium. The direction of flow void tended to deviate to the opposite side within the left atrium in MVP. The frame showing maximal area of flow void was demonstrated in mid-systole in 24 of the 36 patients (67%). The distance, area and volume of flow void were concordant with the grade from color Doppler flow images. The volumes of flow void and the left atrium correlated (n=19, r=0.74, p<0.05) in MVP. In conclusion, cine MR images in several different planes or contiguous multiple slices are useful in determining spatial orientation and the extent and timing of mitral regurgitation noninvasively. Furthermore, calculation of the volume of flow void enables the assessment of the semiquantitation of mitral regurgitation. (author)

Cine y psicología: las emociones en el cine de terror y la comedia en personajes trastornados

OpenAIRE

Cabrera Muñoz, Beatriz

2013-01-01

Se analiza la visión que se ha dado en el cine sobre los trastornos de la personalidad. Cómo el comunicador construye a esos personajes para darle la mayor credibilidad y realidad posible. Se repasan las diferentes estrategias empleadas en el lenguaje cinematográfico en los géneros de terror y comedia

Feasibility of free-breathing, GRAPPA-based, real-time cardiac cine assessment of left-ventricular function in cardiovascular patients at 3T.

Science.gov (United States)

Zhu, Xiaomei; Schwab, Felix; Marcus, Roy; Hetterich, Holger; Theisen, Daniel; Kramer, Harald; Notohamiprodjo, Mike; Schlett, Christopher L; Nikolaou, Konstantin; Reiser, Maximilian F; Bamberg, Fabian

2015-05-01

To determine the feasibility of free-breathing, GRAPPA-based, real-time (RT) cine 3T cardiac magnetic resonance imaging (MRI) with high acceleration factors for the assessment of left-ventricular function in a cohort of patients as compared to conventional segmented cine imaging. In this prospective cohort study, subjects with various cardiac conditions underwent MRI involving two RT cine sequences (high resolution and low resolution) and standard segmented cine imaging. Standard qualitative and quantitative parameters of left-ventricular function were quantified. Among 25 subjects, 24 were included in the analysis (mean age: 50.5±21 years, 67% male, 25% with cardiomyopathy). RT cine derived quantitative parameters of volumes and left ventricular mass were strongly correlated with segmented cine imaging (intraclass correlation coefficient [ICC]: >0.72 for both RT cines) but correlation for peak ejection and filling rates were moderate to poor for both RT cines (ICCcines significantly underestimated peak ejection and filling rates (>103.2±178 ml/s). Among patient-related factors, heart rate was strongly predictive for deviation of measurements (pcine MRI at 3T is feasible for qualitative and quantitative assessment of left ventricular function for low and high-resolution sequences but results in significant underestimation of systolic function, peak ejection and filling rates. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Breast tumor segmentation in high resolution x-ray phase contrast analyzer based computed tomography.

Science.gov (United States)

Brun, E; Grandl, S; Sztrókay-Gaul, A; Barbone, G; Mittone, A; Gasilov, S; Bravin, A; Coan, P

2014-11-01

Phase contrast computed tomography has emerged as an imaging method, which is able to outperform present day clinical mammography in breast tumor visualization while maintaining an equivalent average dose. To this day, no segmentation technique takes into account the specificity of the phase contrast signal. In this study, the authors propose a new mathematical framework for human-guided breast tumor segmentation. This method has been applied to high-resolution images of excised human organs, each of several gigabytes. The authors present a segmentation procedure based on the viscous watershed transform and demonstrate the efficacy of this method on analyzer based phase contrast images. The segmentation of tumors inside two full human breasts is then shown as an example of this procedure's possible applications. A correct and precise identification of the tumor boundaries was obtained and confirmed by manual contouring performed independently by four experienced radiologists. The authors demonstrate that applying the watershed viscous transform allows them to perform the segmentation of tumors in high-resolution x-ray analyzer based phase contrast breast computed tomography images. Combining the additional information provided by the segmentation procedure with the already high definition of morphological details and tissue boundaries offered by phase contrast imaging techniques, will represent a valuable multistep procedure to be used in future medical diagnostic applications.

Subacute and Chronic Left Ventricular Myocardial Scar: Accuracy of Texture Analysis on Nonenhanced Cine MR Images.

Science.gov (United States)

Baessler, Bettina; Mannil, Manoj; Oebel, Sabrina; Maintz, David; Alkadhi, Hatem; Manka, Robert

2018-01-01

Purpose To test whether texture analysis (TA) allows for the diagnosis of subacute and chronic myocardial infarction (MI) on noncontrast material-enhanced cine cardiac magnetic resonance (MR) images. Materials and Methods In this retrospective, institutional review board-approved study, 120 patients who underwent cardiac MR imaging and showed large transmural (volume of enhancement on late gadolinium enhancement [LGE] images >20%, n = 72) or small (enhanced volume ≤20%, n = 48) subacute or chronic ischemic scars were included. Sixty patients with normal cardiac MR imaging findings served as control subjects. Regions of interest for TA encompassing the left ventricle were drawn by two blinded, independent readers on cine images in end systole by using a freely available software package. Stepwise dimension reduction and texture feature selection based on reproducibility, machine learning, and correlation analyses were performed for selecting features, enabling the diagnosis of MI on nonenhanced cine MR images by using LGE imaging as the standard of reference. Results Five independent texture features allowed for differentiation between ischemic scar and normal myocardium on cine MR images in both subgroups: Teta1, Perc.01, Variance, WavEnHH.s-3, and S(5,5)SumEntrp (in patients with large MI: all P values cine MR images, with an area under the curve of 0.93 and 0.92, respectively. Conclusion This proof-of-concept study indicates that TA of nonenhanced cine MR images allows for the diagnosis of subacute and chronic MI with high accuracy. © RSNA, 2017 Online supplemental material is available for this article.

Development of automatic extraction method of left ventricular contours on long axis view MR cine images

International Nuclear Information System (INIS)

Utsunomiya, Shinichi; Iijima, Naoto; Yamasaki, Kazunari; Fujita, Akinori

1995-01-01

In the MRI cardiac function analysis, left ventricular volume curves and diagnosis parameters are obtained by extracting the left ventricular cavities as regions of interest (ROI) from long axis view MR cine images. The ROI extractions had to be done by manual operations, because automatization of the extraction is difficult. A long axis view left ventricular contour consists of a cardiac wall part and an aortic valve part. The above mentioned difficulty is due to the decline of contrast on the cardiac wall part, and the disappearance of edge on the aortic valve part. In this paper, we report a new automatic extraction method for long axis view MR cine images, which needs only 3 manually indicated points on the 1st image to extract all the contours from the total sequence of images. At first, candidate points of a contour are detected by edge detection. Then, selecting the best matched combination of candidate points by Dynamic Programming, the cardiac wall part is automatically extracted. The aortic valve part is manually extracted for the 1st image by indicating both the end points, and is automatically extracted for the rest of the images, by utilizing the aortic valve motion characteristics throughout a cardiac cycle. (author)

Ideal-observer detectability in photon-counting differential phase-contrast imaging using a linear-systems approach

Energy Technology Data Exchange (ETDEWEB)

Fredenberg, Erik; Danielsson, Mats; Stayman, J. Webster; Siewerdsen, Jeffrey H.; Aslund, Magnus [Research and Development, Philips Women' s Healthcare, Smidesvaegen 5, SE-171 41 Solna, Sweden and Department of Physics, Royal Institute of Technology, AlbaNova, SE-106 91 Stockholm (Sweden); Department of Physics, Royal Institute of Technology, AlbaNova, SE-106 91 Stockholm (Sweden); Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Department of Biomedical Engineering and Department of Radiology, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Research and Development, Philips Women' s Healthcare, Smidesvaegen 5, SE-171 41 Solna (Sweden)

2012-09-15

Purpose: To provide a cascaded-systems framework based on the noise-power spectrum (NPS), modulation transfer function (MTF), and noise-equivalent number of quanta (NEQ) for quantitative evaluation of differential phase-contrast imaging (Talbot interferometry) in relation to conventional absorption contrast under equal-dose, equal-geometry, and, to some extent, equal-photon-economy constraints. The focus is a geometry for photon-counting mammography. Methods: Phase-contrast imaging is a promising technology that may emerge as an alternative or adjunct to conventional absorption contrast. In particular, phase contrast may increase the signal-difference-to-noise ratio compared to absorption contrast because the difference in phase shift between soft-tissue structures is often substantially larger than the absorption difference. We have developed a comprehensive cascaded-systems framework to investigate Talbot interferometry, which is a technique for differential phase-contrast imaging. Analytical expressions for the MTF and NPS were derived to calculate the NEQ and a task-specific ideal-observer detectability index under assumptions of linearity and shift invariance. Talbot interferometry was compared to absorption contrast at equal dose, and using either a plane wave or a spherical wave in a conceivable mammography geometry. The impact of source size and spectrum bandwidth was included in the framework, and the trade-off with photon economy was investigated in some detail. Wave-propagation simulations were used to verify the analytical expressions and to generate example images. Results: Talbot interferometry inherently detects the differential of the phase, which led to a maximum in NEQ at high spatial frequencies, whereas the absorption-contrast NEQ decreased monotonically with frequency. Further, phase contrast detects differences in density rather than atomic number, and the optimal imaging energy was found to be a factor of 1.7 higher than for absorption

Ideal-observer detectability in photon-counting differential phase-contrast imaging using a linear-systems approach

International Nuclear Information System (INIS)

Fredenberg, Erik; Danielsson, Mats; Stayman, J. Webster; Siewerdsen, Jeffrey H.; Åslund, Magnus

2012-01-01

Purpose: To provide a cascaded-systems framework based on the noise-power spectrum (NPS), modulation transfer function (MTF), and noise-equivalent number of quanta (NEQ) for quantitative evaluation of differential phase-contrast imaging (Talbot interferometry) in relation to conventional absorption contrast under equal-dose, equal-geometry, and, to some extent, equal-photon-economy constraints. The focus is a geometry for photon-counting mammography. Methods: Phase-contrast imaging is a promising technology that may emerge as an alternative or adjunct to conventional absorption contrast. In particular, phase contrast may increase the signal-difference-to-noise ratio compared to absorption contrast because the difference in phase shift between soft-tissue structures is often substantially larger than the absorption difference. We have developed a comprehensive cascaded-systems framework to investigate Talbot interferometry, which is a technique for differential phase-contrast imaging. Analytical expressions for the MTF and NPS were derived to calculate the NEQ and a task-specific ideal-observer detectability index under assumptions of linearity and shift invariance. Talbot interferometry was compared to absorption contrast at equal dose, and using either a plane wave or a spherical wave in a conceivable mammography geometry. The impact of source size and spectrum bandwidth was included in the framework, and the trade-off with photon economy was investigated in some detail. Wave-propagation simulations were used to verify the analytical expressions and to generate example images. Results: Talbot interferometry inherently detects the differential of the phase, which led to a maximum in NEQ at high spatial frequencies, whereas the absorption-contrast NEQ decreased monotonically with frequency. Further, phase contrast detects differences in density rather than atomic number, and the optimal imaging energy was found to be a factor of 1.7 higher than for absorption

Binocular contrast-gain control for natural scenes: Image structure and phase alignment.