WorldWideScience

Sample records for imaging cmr protocols

  1. Differences in quantitative assessment of myocardial scar and gray zone by LGE-CMR imaging using established gray zone protocols.

    Science.gov (United States)

    Mesubi, Olurotimi; Ego-Osuala, Kelechi; Jeudy, Jean; Purtilo, James; Synowski, Stephen; Abutaleb, Ameer; Niekoop, Michelle; Abdulghani, Mohammed; Asoglu, Ramazan; See, Vincent; Saliaris, Anastasios; Shorofsky, Stephen; Dickfeld, Timm

    2015-02-01

    Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging is the gold standard for myocardial scar evaluation. Heterogeneous areas of scar ('gray zone'), may serve as arrhythmogenic substrate. Various gray zone protocols have been correlated to clinical outcomes and ventricular tachycardia channels. This study assessed the quantitative differences in gray zone and scar core sizes as defined by previously validated signal intensity (SI) threshold algorithms. High quality LGE-CMR images performed in 41 cardiomyopathy patients [ischemic (33) or non-ischemic (8)] were analyzed using previously validated SI threshold methods [Full Width at Half Maximum (FWHM), n-standard deviation (NSD) and modified-FWHM]. Myocardial scar was defined as scar core and gray zone using SI thresholds based on these methods. Scar core, gray zone and total scar sizes were then computed and compared among these models. The median gray zone mass was 2-3 times larger with FWHM (15 g, IQR: 8-26 g) compared to NSD or modified-FWHM (5 g, IQR: 3-9 g; and 8 g. IQR: 6-12 g respectively, p zone extent (percentage of total scar that was gray zone) also varied significantly among the three methods, 51 % (IQR: 42-61 %), 17 % (IQR: 11-21 %) versus 38 % (IQR: 33-43 %) for FWHM, NSD and modified-FWHM respectively (p zone and scar core. Infarct core and total myocardial scar mass also differ using these methods. Further evaluation of the most accurate quantification method is needed.

  2. Standardized cardiovascular magnetic resonance imaging (CMR protocols, society for cardiovascular magnetic resonance: board of trustees task force on standardized protocols

    Directory of Open Access Journals (Sweden)

    Kim Raymond J

    2008-07-01

    Full Text Available Index 1. General techniques 1.1. Stress and safety equipment 1.2. Left ventricular (LV structure and function module 1.3. Right ventricular (RV structure and function module 1.4. Gadolinium dosing module. 1.5. First pass perfusion 1.6. Late gadolinium enhancement (LGE 2. Disease specific protocols 2.1. Ischemic heart disease 2.1.1. Acute myocardial infarction (MI 2.1.2. Chronic ischemic heart disease and viability 2.1.3. Dobutamine stress 2.1.4. Adenosine stress perfusion 2.2. Angiography: 2.2.1. Peripheral magnetic resonance angiography (MRA 2.2.2. Thoracic MRA 2.2.3. Anomalous coronary arteries 2.2.4. Pulmonary vein evaluation 2.3. Other 2.3.1. Non-ischemic cardiomyopathy 2.3.2. Arrhythmogenic right ventricular cardiomyopathy (ARVC 2.3.3. Congenital heart disease 2.3.4. Valvular heart disease 2.3.5. Pericardial disease 2.3.6. Masses

  3. PET-CMR in heart failure - synergistic or redundant imaging?

    Science.gov (United States)

    Quail, Michael A; Sinusas, Albert J

    2017-07-01

    Imaging in heart failure (HF) provides data for diagnosis, prognosis and disease monitoring. Both MRI and nuclear imaging techniques have been successfully used for this purpose in HF. Positron Emission Tomography-Cardiac Magnetic Resonance (PET-CMR) is an example of a new multimodality diagnostic imaging technique with potential applications in HF. The threshold for adopting a new diagnostic tool to clinical practice must necessarily be high, lest they exacerbate costs without improving care. New modalities must demonstrate clinical superiority, or at least equivalence, combined with another important advantage, such as lower cost or improved patient safety. The purpose of this review is to outline the current status of multimodality PET-CMR with regard to HF applications, and determine whether the clinical utility of this new technology justifies the cost.

  4. Advanced myocardial tissue characterisation by a multi-component CMR protocol in patients with rheumatoid arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Greulich, Simon; Kaesemann, Philipp; Patrascu, Alexandru; Sechtem, Udo; Mahrholdt, Heiko [Robert-Bosch-Medical Center Stuttgart, Division of Cardiology, Stuttgart (Germany); Mayr, Agnes [University Hospital Innsbruck, Division of Radiology, Innsbruck (Austria); Kitterer, Daniel; Latus, Joerg; Braun, Niko; Alscher, M.D. [Robert-Bosch-Medical Center Stuttgart, Division of Nephrology, Department of Internal Medicine, Stuttgart (Germany); Henes, Joerg [University Hospital Tuebingen, Centre for Interdisciplinary Clinical Immunology, Rheumatology and Auto-inflammatory Diseases and Department of Internal Medicine II (Oncology, Haematology, Immunology, Rheumatology, Pulmology), Tuebingen (Germany); Vecchio, Francesco [Robert-Bosch-Medical Center Stuttgart, Division of Cardiology, Stuttgart (Germany); Universita degli Studi di Roma ' ' Tor Vergata' ' , Division of Cardiology, Rome (Italy); Greiser, Andreas; Groeninger, Stefan [Siemens Healthcare GmbH, Erlangen (Germany); Romeo, Francesco [Universita degli Studi di Roma ' ' Tor Vergata' ' , Division of Cardiology, Rome (Italy)

    2017-11-15

    Rheumatoid arthritis (RA) patients are at increased risk of suffering from adverse cardiovascular events. Cardiovascular magnetic resonance (CMR) mapping techniques might be appropriate tools to complement late gadolinium enhancement (LGE) for the assessment of myocardial involvement. This study aimed to perform advanced myocardial tissue characterisation in RA patients by a multicomponent CMR protocol. 22 RA patients were prospectively enrolled and underwent CMR, including LGE and T1/T2 mapping sequences; 20 volunteers served as controls. Mean LV-EF was 66%; prevalence of LGE was 18%. RA patients had increased native T1 (985 vs. 959 ms, p = 0.03), expanded extracellular volume (ECV) (27 vs. 25%, p = 0.02) and higher T2 values (52 vs. 49 ms, p < 0.001) compared to controls irrespective of the presence of LGE. T2 mapping showed the highest prevalence of values beyond the 95% percentile of controls. RA patients demonstrated higher T1, ECV and T2 values compared to controls, with most significant differences for T2. Since these results seem to be independent of the presence of LGE, advanced myocardial tissue characterisation including CMR mapping techniques in addition to LGE-CMR might be useful in the evaluation of myocardial involvement in RA patients. (orig.)

  5. Cardiovascular magnetic resonance imaging (CMR) reveals characteristic pattern of myocardial damage in patients with mitochondrial myopathy.

    Science.gov (United States)

    Yilmaz, Ali; Gdynia, Hans-Jürgen; Ponfick, Matthias; Rösch, Sabine; Lindner, Alfred; Ludolph, Albert C; Sechtem, Udo

    2012-04-01

    Mitochondrial myopathy comprises various clinical subforms of neuromuscular disorders that are characterised by impaired mitochondrial energy metabolism due to dysfunction of the mitochondrial respiratory chain. No comprehensive and targeted cardiovascular magnetic resonance (CMR) studies have been performed so far in patients with mitochondrial disorders. The present study aimed at characterising cardiac disease manifestations in patients with mitochondrial myopathy and elucidating the in vivo cardiac damage pattern of patients with different subforms of mitochondrial disease by CMR studies. In a prospective study, 37 patients with mitochondrial myopathy underwent comprehensive neurological and cardiac evaluations including physical examination, resting ECG and CMR. The CMR studies comprised cine-CMR, T2-weighted "edema" imaging and T1-weighted late-gadolinium-enhancement (LGE) imaging. Various patterns and degrees of skeletal myopathy were present in the participants of this study, whereas clinical symptoms such as chest pain symptoms (in eight (22%) patients) and various degrees of dyspnea (in 16 (43%) patients) were less frequent. Pathological ECG findings were documented in eight (22%) patients. T2-weighted "edema" imaging was positive in one (3%) patient with MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) only. LGE imaging demonstrated the presence of non-ischemic LGE in 12 (32%) patients: 10 out of 24 (42%) patients with CPEO (chronic progressive external ophthalmoplegia) or KSS (Kearns-Sayre syndrome) and 2 of 3 (67%) patients with MELAS were LGE positive. All 10 LGE-positive patients with CPEO or KSS demonstrated a potentially typical pattern of diffuse intramural LGE in the left-ventricular (LV) inferolateral segments. Cardiac involvement is a frequent finding in patients with mitochondrial myopathy. A potentially characteristic pattern of diffuse intramural LGE in the LV inferolateral segments was identified in

  6. Probability mapping of scarred myocardium using texture and intensity features in CMR images

    Science.gov (United States)

    2013-01-01

    Background The myocardium exhibits heterogeneous nature due to scarring after Myocardial Infarction (MI). In Cardiac Magnetic Resonance (CMR) imaging, Late Gadolinium (LG) contrast agent enhances the intensity of scarred area in the myocardium. Methods In this paper, we propose a probability mapping technique using Texture and Intensity features to describe heterogeneous nature of the scarred myocardium in Cardiac Magnetic Resonance (CMR) images after Myocardial Infarction (MI). Scarred tissue and non-scarred tissue are represented with high and low probabilities, respectively. Intermediate values possibly indicate areas where the scarred and healthy tissues are interwoven. The probability map of scarred myocardium is calculated by using a probability function based on Bayes rule. Any set of features can be used in the probability function. Results In the present study, we demonstrate the use of two different types of features. One is based on the mean intensity of pixel and the other on underlying texture information of the scarred and non-scarred myocardium. Examples of probability maps computed using the mean intensity of pixel and the underlying texture information are presented. We hypothesize that the probability mapping of myocardium offers alternate visualization, possibly showing the details with physiological significance difficult to detect visually in the original CMR image. Conclusion The probability mapping obtained from the two features provides a way to define different cardiac segments which offer a way to identify areas in the myocardium of diagnostic importance (like core and border areas in scarred myocardium). PMID:24053280

  7. CMR in Heart Failure.

    OpenAIRE

    Sado, D. M.; Hasleton, J. M.; Herrey, A. S.; Moon, J. C.

    2011-01-01

    Heart Failure (HF) is a common syndrome with multiple causes. Cardiovascular magnetic resonance (CMR) is a medical imaging technique with significant advantages, allowing the understanding of aetiology and pathophysiology of HF in the individual patient, permitting specific therapy to be administered and predicting prognosis. This paper discusses the diverse role of CMR in HF.

  8. Remodeling after acute myocardial infarction: mapping ventricular dilatation using three dimensional CMR image registration

    Directory of Open Access Journals (Sweden)

    O’Regan Declan P

    2012-06-01

    Full Text Available Abstract Background Progressive heart failure due to remodeling is a major cause of morbidity and mortality following myocardial infarction. Conventional clinical imaging measures global volume changes, and currently there is no means of assessing regional myocardial dilatation in relation to ischemic burden. Here we use 3D co-registration of Cardiovascular Magnetic Resonance (CMR images to assess the long-term effects of ischemia-reperfusion injury on left ventricular structure after acute ST-elevation myocardial infarction (STEMI. Methods Forty six patients (age range 33–77 years underwent CMR imaging within 7 days following primary percutaneous coronary intervention (PPCI for acute STEMI with follow-up at one year. Functional cine imaging and Late Gadolinium Enhancement (LGE were segmented and co-registered. Local left ventricular wall dilatation was assessed by using intensity-based similarities to track the structural changes in the heart between baseline and follow-up. Results are expressed as means, standard errors and 95% confidence interval (CI of the difference. Results Local left ventricular remodeling within infarcted myocardium was greater than in non-infarcted myocardium (1.6% ± 1.0 vs 0.3% ± 0.9, 95% CI: -2.4% – -0.2%, P = 0.02. One-way ANOVA revealed that transmural infarct thickness had a significant effect on the degree of local remodeling at one year (P 20% (4.8% ± 1.4 vs −0.15% ± 1.2, 95% CI: -8.9% – -0.9%, P = 0.017. Conclusions The severity of ischemic injury has a significant effect on local ventricular wall remodeling with only modest dilatation observed within non-ischemic myocardium. Limitation of chronic remodeling may therefore depend on therapies directed at modulating ischemia-reperfusion injury. CMR co-registration has potential for assessing dynamic changes in ventricular structure in relation to therapeutic interventions.

  9. Cloud-processed 4D CMR flow imaging for pulmonary flow quantification

    Energy Technology Data Exchange (ETDEWEB)

    Chelu, Raluca G., E-mail: ralucachelu@hotmail.com [Department of Radiology, Erasmus MC, Rotterdam (Netherlands); Department of Cardiology, Erasmus MC, Rotterdam (Netherlands); Wanambiro, Kevin W. [Department of Radiology, Erasmus MC, Rotterdam (Netherlands); Department of Radiology, Aga Khan University Hospital, Nairobi (Kenya); Hsiao, Albert [Department of Radiology, University of California, San Diego, CA (United States); Swart, Laurens E. [Department of Radiology, Erasmus MC, Rotterdam (Netherlands); Department of Cardiology, Erasmus MC, Rotterdam (Netherlands); Voogd, Teun [Department of Radiology, Erasmus MC, Rotterdam (Netherlands); Hoven, Allard T. van den; Kranenburg, Matthijs van [Department of Cardiology, Erasmus MC, Rotterdam (Netherlands); Coenen, Adriaan [Department of Radiology, Erasmus MC, Rotterdam (Netherlands); Department of Cardiology, Erasmus MC, Rotterdam (Netherlands); Boccalini, Sara [Department of Radiology, Erasmus MC, Rotterdam (Netherlands); Department of Radiology, University Hospital, Genoa (Italy); Wielopolski, Piotr A. [Department of Radiology, Erasmus MC, Rotterdam (Netherlands); Vogel, Mika W. [MR Applications and Workflow – Europe, GE Healthcare B.V. Hoevelaken (Netherlands); Krestin, Gabriel P. [Department of Radiology, Erasmus MC, Rotterdam (Netherlands); Vasanawala, Shreyas S. [Department of Radiology, Stanford University, Stanford, CA (United States); Budde, Ricardo P.J. [Department of Radiology, Erasmus MC, Rotterdam (Netherlands); Department of Cardiology, Erasmus MC, Rotterdam (Netherlands); Roos-Hesselink, Jolien W. [Department of Cardiology, Erasmus MC, Rotterdam (Netherlands); Nieman, Koen [Department of Radiology, Erasmus MC, Rotterdam (Netherlands); Department of Cardiology, Erasmus MC, Rotterdam (Netherlands)

    2016-10-15

    Highlights: • With 4D flow, any plane of interest can be interactively chosen for quantitative measurements. • Anatomical and flow data are obtained during an approximately 10-min free-breathing scan. • 4D CMR flow measurements correlated well with the 2D PC ones. • Eddy current correction is important for good results with 4D flow. - Abstract: Objectives: In this study, we evaluated a cloud-based platform for cardiac magnetic resonance (CMR) four-dimensional (4D) flow imaging, with fully integrated correction for eddy currents, Maxwell phase effects, and gradient field non-linearity, to quantify forward flow, regurgitation, and peak systolic velocity over the pulmonary artery. Methods: We prospectively recruited 52 adult patients during one-year period from July 2014. The 4D flow and planar (2D) phase-contrast (PC) were acquired during same scanning session, but 4D flow was scanned after injection of a gadolinium-based contrast agent. Eddy-currents were semi-automatically corrected using the web-based software. Flow over pulmonary valve was measured and the 4D flow values were compared against the 2D PC ones. Results: The mean forward flow was 92 (±30) ml/cycle measured with 4D flow and 86 (±29) ml/cycle measured with 2D PC, with a correlation of 0.82 and a mean difference of −6 ml/cycle (−41–29). For the regurgitant fraction the correlation was 0.85 with a mean difference of −0.95% (−17–15). Mean peak systolic velocity measured with 4D flow was 92 (±49) cm/s and 108 (±56) cm/s with 2D PC, having a correlation of 0.93 and a mean difference of 16 cm/s (−24–55). Conclusion: 4D flow imaging post-processed with an integrated cloud-based application accurately quantifies pulmonary flow. However, it may underestimate the peak systolic velocity.

  10. Cloud-processed 4D CMR flow imaging for pulmonary flow quantification

    International Nuclear Information System (INIS)

    Chelu, Raluca G.; Wanambiro, Kevin W.; Hsiao, Albert; Swart, Laurens E.; Voogd, Teun; Hoven, Allard T. van den; Kranenburg, Matthijs van; Coenen, Adriaan; Boccalini, Sara; Wielopolski, Piotr A.; Vogel, Mika W.; Krestin, Gabriel P.; Vasanawala, Shreyas S.; Budde, Ricardo P.J.; Roos-Hesselink, Jolien W.; Nieman, Koen

    2016-01-01

    Highlights: • With 4D flow, any plane of interest can be interactively chosen for quantitative measurements. • Anatomical and flow data are obtained during an approximately 10-min free-breathing scan. • 4D CMR flow measurements correlated well with the 2D PC ones. • Eddy current correction is important for good results with 4D flow. - Abstract: Objectives: In this study, we evaluated a cloud-based platform for cardiac magnetic resonance (CMR) four-dimensional (4D) flow imaging, with fully integrated correction for eddy currents, Maxwell phase effects, and gradient field non-linearity, to quantify forward flow, regurgitation, and peak systolic velocity over the pulmonary artery. Methods: We prospectively recruited 52 adult patients during one-year period from July 2014. The 4D flow and planar (2D) phase-contrast (PC) were acquired during same scanning session, but 4D flow was scanned after injection of a gadolinium-based contrast agent. Eddy-currents were semi-automatically corrected using the web-based software. Flow over pulmonary valve was measured and the 4D flow values were compared against the 2D PC ones. Results: The mean forward flow was 92 (±30) ml/cycle measured with 4D flow and 86 (±29) ml/cycle measured with 2D PC, with a correlation of 0.82 and a mean difference of −6 ml/cycle (−41–29). For the regurgitant fraction the correlation was 0.85 with a mean difference of −0.95% (−17–15). Mean peak systolic velocity measured with 4D flow was 92 (±49) cm/s and 108 (±56) cm/s with 2D PC, having a correlation of 0.93 and a mean difference of 16 cm/s (−24–55). Conclusion: 4D flow imaging post-processed with an integrated cloud-based application accurately quantifies pulmonary flow. However, it may underestimate the peak systolic velocity.

  11. 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.)

  12. 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.)

  13. 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.

  14. Properties of CMR composites

    Indian Academy of Sciences (India)

    Unknown

    Department of Metallurgical Engineering and Materials Science, Indian. Institute ... Colossal magnetoresistance (CMR) composites form an interesting field ..... field and composition sensitive competition between the positive and negative MR.

  15. Dark blood versus bright blood T2* acquisition in cardiovascular magnetic resonance (CMR) for thalassaemia major (TM) patients: Evaluation of feasibility, reproducibility and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Liguori, Carlo, E-mail: c.liguori@unicampus.it [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Di Giampietro, Ilenia; Pitocco, Francesca; De Vivo, Aldo Eros [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Schena, Emiliano [Unit of Measurements and Biomedical Instrumentation, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Mortato, Luca [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Pirro, Federica [Department of Biomaging and Radiological Sciences, Catholic University of Sacred Herart, Largo A. Gemelli 1, 00135 Rome (Italy); Cianciulli, Paolo [Thalassemia Unit, Ospedale Sant Eugenio, Piazzale dell’Umanesimo 10, 00143 Rome (Italy); Zobel, Bruno Beomonte [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy)

    2014-01-15

    Objectives: To compare the effectiveness of dark blood (DB) versus bright blood (BB) sequences. To assess the intra and inter-observer variability and inter-study reproducibility between BB versus DB. To evaluate image quality level in the two sequences. Methods: In a setting of 138 patients we performed CMR using cardiac gated Gradient-multiecho single breath-hold BB and DB sequences in the middle ventricular septum. Each acquisition was repeated during the same exam. Truncation method was used to account for background noise. Image quality (IQ) was assessed using a 5 point grading scale and image analysis was conducted by 2 experienced observers. Results: Compared with the conventional BB acquisition, the coefficient of correlation and significance of the DB technique was superior for intra-observer reproducibility (p < 0.001), inter-observer reproducibility (p < 0.001) and inter-study reproducibility (p < 0.001). The variability is also lower for DB sequences for T2* values <14 ms. Assessment of artifacts showed a superior score for DB versus BB scans (4 versus 3, p < 0.001). Conclusions: Improvement in terms of inter observer and inter study variability using DB sequences was obtained. The greatest disparity between them was seen in inter-study reproducibility and higher IQ in DB was seen. Study demonstrates better performance of DB imaging compared to BB in presence of comparable effectiveness.

  16. Diagnostic performance of semi-quantitative and quantitative stress CMR perfusion analysis: a meta-analysis.

    Science.gov (United States)

    van Dijk, R; van Assen, M; Vliegenthart, R; de Bock, G H; van der Harst, P; Oudkerk, M

    2017-11-27

    Stress cardiovascular magnetic resonance (CMR) perfusion imaging is a promising modality for the evaluation of coronary artery disease (CAD) due to high spatial resolution and absence of radiation. Semi-quantitative and quantitative analysis of CMR perfusion are based on signal-intensity curves produced during the first-pass of gadolinium contrast. Multiple semi-quantitative and quantitative parameters have been introduced. Diagnostic performance of these parameters varies extensively among studies and standardized protocols are lacking. This study aims to determine the diagnostic accuracy of semi- quantitative and quantitative CMR perfusion parameters, compared to multiple reference standards. Pubmed, WebOfScience, and Embase were systematically searched using predefined criteria (3272 articles). A check for duplicates was performed (1967 articles). Eligibility and relevance of the articles was determined by two reviewers using pre-defined criteria. The primary data extraction was performed independently by two researchers with the use of a predefined template. Differences in extracted data were resolved by discussion between the two researchers. The quality of the included studies was assessed using the 'Quality Assessment of Diagnostic Accuracy Studies Tool' (QUADAS-2). True positives, false positives, true negatives, and false negatives were subtracted/calculated from the articles. The principal summary measures used to assess diagnostic accuracy were sensitivity, specificity, andarea under the receiver operating curve (AUC). Data was pooled according to analysis territory, reference standard and perfusion parameter. Twenty-two articles were eligible based on the predefined study eligibility criteria. The pooled diagnostic accuracy for segment-, territory- and patient-based analyses showed good diagnostic performance with sensitivity of 0.88, 0.82, and 0.83, specificity of 0.72, 0.83, and 0.76 and AUC of 0.90, 0.84, and 0.87, respectively. In per territory

  17. Comparison of CT and CMR for detection and quantification of carotid artery calcification

    DEFF Research Database (Denmark)

    Mujaj, Blerim; Lorza, Andrés M. Arias; van Engelen, Arna

    2017-01-01

    interscan interval: 4.9 ± 1.2 years). We investigated the correlation between the amount of calcification measured on CT and CMR using Spearman's correlation coefficient, Bland-Altman plots, and linear regression. In addition, using logistic regression modeling, we assessed the association of CT and CMR...... larger. Finally, calcification volume assessed with either imaging modality was associated with a history of stroke with similar effect estimates (odds ratio (OR) per 1-SD increase in calcification volume: 1.52 (95% CI:1.00;2.30) for CT, and 1.47 (95% CI:1.01;2.14) for CMR. CONCLUSION: CT based and CMR...

  18. Magnetic resonance imaging protocols for paediatric neuroradiology

    International Nuclear Information System (INIS)

    Saunders, Dawn E.; Thompson, Clare; Gunny, Roxanne; Jones, Rod; Cox, Tim; Chong, Wui Khean

    2007-01-01

    Increasingly, radiologists are encouraged to have protocols for all imaging studies and to include imaging guidelines in care pathways set up by the referring clinicians. This is particularly advantageous in MRI where magnet time is limited and a radiologist's review of each patient's images often results in additional sequences and longer scanning times without the advantage of improvement in diagnostic ability. The difficulties of imaging small children and the challenges presented to the radiologist as the brain develops are discussed. We present our protocols for imaging the brain and spine of children based on 20 years experience of paediatric neurological MRI. The protocols are adapted to suit children under the age of 2 years, small body parts and paediatric clinical scenarios. (orig.)

  19. CMR of microvascular obstruction and hemorrhage in myocardial infarction

    Directory of Open Access Journals (Sweden)

    Wu Katherine C

    2012-09-01

    Full Text Available Abstract Microvascular obstruction (MO or no-reflow phenomenon is an established complication of coronary reperfusion therapy for acute myocardial infarction. It is increasingly recognized as a poor prognostic indicator and marker of subsequent adverse LV remodeling. Although MO can be assessed using various imaging modalities including electrocardiography, myocardial contrast echocardiography, nuclear scintigraphy, and coronary angiography, evaluation by cardiovascular magnetic resonance (CMR is particularly useful in enhancing its detection, diagnosis, and quantification, as well as following its subsequent effects on infarct evolution and healing. MO assessment has become a routine component of the CMR evaluation of acute myocardial infarction and will increasingly play a role in clinical trials of adjunctive reperfusion agents and strategies. This review will summarize the pathophysiology of MO, current CMR approaches to diagnosis, clinical implications, and future directions needed for improving our understanding of this common clinical problem.

  20. SPECT/CT workflow and imaging protocols

    Energy Technology Data Exchange (ETDEWEB)

    Beckers, Catherine [University Hospital of Liege, Division of Nuclear Medicine and Oncological Imaging, Department of Medical Physics, Liege (Belgium); Hustinx, Roland [University Hospital of Liege, Division of Nuclear Medicine and Oncological Imaging, Department of Medical Physics, Liege (Belgium); Domaine Universitaire du Sart Tilman, Service de Medecine Nucleaire et Imagerie Oncologique, CHU de Liege, Liege (Belgium)

    2014-05-15

    Introducing a hybrid imaging method such as single photon emission computed tomography (SPECT)/CT greatly alters the routine in the nuclear medicine department. It requires designing new workflow processes and the revision of original scheduling process and imaging protocols. In addition, the imaging protocol should be adapted for each individual patient, so that performing CT is fully justified and the CT procedure is fully tailored to address the clinical issue. Such refinements often occur before the procedure is started but may be required at some intermediate stage of the procedure. Furthermore, SPECT/CT leads in many instances to a new partnership with the radiology department. This article presents practical advice and highlights the key clinical elements which need to be considered to help understand the workflow process of SPECT/CT and optimise imaging protocols. The workflow process using SPECT/CT is complex in particular because of its bimodal character, the large spectrum of stakeholders, the multiplicity of their activities at various time points and the need for real-time decision-making. With help from analytical tools developed for quality assessment, the workflow process using SPECT/CT may be separated into related, but independent steps, each with its specific human and material resources to use as inputs or outputs. This helps identify factors that could contribute to failure in routine clinical practice. At each step of the process, practical aspects to optimise imaging procedure and protocols are developed. A decision-making algorithm for justifying each CT indication as well as the appropriateness of each CT protocol is the cornerstone of routine clinical practice using SPECT/CT. In conclusion, implementing hybrid SPECT/CT imaging requires new ways of working. It is highly rewarding from a clinical perspective, but it also proves to be a daily challenge in terms of management. (orig.)

  1. SPECT/CT workflow and imaging protocols

    International Nuclear Information System (INIS)

    Beckers, Catherine; Hustinx, Roland

    2014-01-01

    Introducing a hybrid imaging method such as single photon emission computed tomography (SPECT)/CT greatly alters the routine in the nuclear medicine department. It requires designing new workflow processes and the revision of original scheduling process and imaging protocols. In addition, the imaging protocol should be adapted for each individual patient, so that performing CT is fully justified and the CT procedure is fully tailored to address the clinical issue. Such refinements often occur before the procedure is started but may be required at some intermediate stage of the procedure. Furthermore, SPECT/CT leads in many instances to a new partnership with the radiology department. This article presents practical advice and highlights the key clinical elements which need to be considered to help understand the workflow process of SPECT/CT and optimise imaging protocols. The workflow process using SPECT/CT is complex in particular because of its bimodal character, the large spectrum of stakeholders, the multiplicity of their activities at various time points and the need for real-time decision-making. With help from analytical tools developed for quality assessment, the workflow process using SPECT/CT may be separated into related, but independent steps, each with its specific human and material resources to use as inputs or outputs. This helps identify factors that could contribute to failure in routine clinical practice. At each step of the process, practical aspects to optimise imaging procedure and protocols are developed. A decision-making algorithm for justifying each CT indication as well as the appropriateness of each CT protocol is the cornerstone of routine clinical practice using SPECT/CT. In conclusion, implementing hybrid SPECT/CT imaging requires new ways of working. It is highly rewarding from a clinical perspective, but it also proves to be a daily challenge in terms of management. (orig.)

  2. Myocardial Blood Volume Is Associated with Myocardial Oxygen Consumption: An Experimental Study with CMR in a Canine Model

    Science.gov (United States)

    McCommis, Kyle S.; Zhang, Haosen; Goldstein, Thomas A.; Misselwitz, Bernd; Abendschein, Dana R.; Gropler, Robert J.; Zheng, Jie

    2009-01-01

    OBJECTIVES To evaluate the feasibility of cardiovascular MR (CMR) to determine regional myocardial perfusion and O2 metabolism, and assess the role of myocardial blood volume (MBV) on oxygen supply. BACKGROUND Coronary artery disease presents as an imbalance of myocardial oxygen supply and demand. We have developed relevant CMR methods to determine the relationship of myocardial blood flow (MBF) and MBV to oxygen consumption (MVO2) during pharmacologic hyperemia. METHODS Twenty-one mongrel dogs were studied with varying stenosis severities imposed on the proximal left anterior descending (LAD) coronary artery. MBF and MBV were determined by CMR first-pass perfusion, while the oxygen extraction fraction (OEF) and MVO2 were determined by the myocardial Blood-Oxygen-Level-Dependent (BOLD) effect and Fick’s law, respectively. MR imaging was performed at rest, and during either dipyridamole-induced vasodilation or dobutamine-induced hyperemia. Regional differences in myocardial perfusion and oxygenation were then evaluated. RESULTS Dipyridamole and dobutamine both led to 145–200% increases in MBF and 50–80% increases in MBV in normal perfused myocardium. As expected, MVO2 increased more significantly with dobutamine (~175%) than dipyridamole (~40%). Coronary stenosis resulted in an attenuation of MBF, MBV, and MVO2 in both the LAD-subtended stenosis region and the left circumflex subtended remote region. Liner regression analysis showed that MBV reserve appears to be more correlated with MVO2 reserve during dobutamine stress than MBF reserve, particularly in the stenotic regions. Conversely, MBF reserve appears to be more correlated with MVO2 reserve during dipyridamole, although neither of these differences was significant. CONCLUSIONS Noninvasive evaluation of both myocardial perfusion and oxygenation by CMR facilitates direct monitoring of regional myocardial ischemia and provides a valuable tool for better understanding microvascular pathophysiology. These

  3. CMR assessment after a transapical-transcatheter aortic valve implantation

    International Nuclear Information System (INIS)

    Biere, Loïc; Pinaud, Frédéric; Delépine, Stéphane; Grall, Sylvain; Viot, Nathalie; Mateus, Victor; Rouleau, Frédéric; Corbeau, Jean-Jacques; Prunier, Fabrice

    2014-01-01

    Aims: To describe the time course of myocardial scarring after transapical-transcatheter aortic valve implantation (TA-TAVI) with the Edwards SAPIEN XT™ and the Edwards SAPIEN™ prosthesis in a 3-month follow-up study using cardiac magnetic resonance imaging (CMR). Methods: In 20 TA-TAVI patients, CMR was performed at discharge and 3 months (3M). Cine-MRI was used for left ventricular (LV) functional assessment, and late gadolinium enhancement (LGE) imaging was employed for detecting the presence of myocardial scarring. Special attention was given to any artifacts caused by the prosthesis, which were consequently defined using a three-grade artifact scale. Results: We systematically reported the presence of small LGE hyperintensity relating to the apical segment, with no variation found between discharge and 3 M (2.8 ± 1.6 g vs. 2.35 ± 1.1 g). LV ejection fraction, end-diastolic, and end-systolic volumes did not significantly vary. A small area of apical akinesia was observed, with no improvement at follow-up. Whereas the Edwards SAPIEN XT™ prosthesis and the Edwards SAPIEN™ prosthesis are both constituted by metallic stenting structure, the Edwards SAPIEN™ was responsible for a larger signal void, thus potentially limiting the diagnostic performance of CMR. Conclusions: CMR may be performed safely in the context of TA-TAVI. The presence of a very small apical infarction correlating with focal akinesia was observed. As expected, the Edwards SAPIEN XT™ prosthesis was shown to be particularly suitable for CMR assessment

  4. Chest magnetic resonance imaging: a protocol suggestion

    Directory of Open Access Journals (Sweden)

    Bruno Hochhegger

    2015-12-01

    Full Text Available Abstract In the recent years, with the development of ultrafast sequences, magnetic resonance imaging (MRI has been established as a valuable diagnostic modality in body imaging. Because of improvements in speed and image quality, MRI is now ready for routine clinical use also in the study of pulmonary diseases. The main advantage of MRI of the lungs is its unique combination of morphological and functional assessment in a single imaging session. In this article, the authors review most technical aspects and suggest a protocol for performing chest MRI. The authors also describe the three major clinical indications for MRI of the lungs: staging of lung tumors; evaluation of pulmonary vascular diseases; and investigation of pulmonary abnormalities in patients who should not be exposed to radiation.

  5. Atlas-based analysis of cardiac shape and function: correction of regional shape bias due to imaging protocol for population studies.

    Science.gov (United States)

    Medrano-Gracia, Pau; Cowan, Brett R; Bluemke, David A; Finn, J Paul; Kadish, Alan H; Lee, Daniel C; Lima, Joao A C; Suinesiaputra, Avan; Young, Alistair A

    2013-09-13

    Cardiovascular imaging studies generate a wealth of data which is typically used only for individual study endpoints. By pooling data from multiple sources, quantitative comparisons can be made of regional wall motion abnormalities between different cohorts, enabling reuse of valuable data. Atlas-based analysis provides precise quantification of shape and motion differences between disease groups and normal subjects. However, subtle shape differences may arise due to differences in imaging protocol between studies. A mathematical model describing regional wall motion and shape was used to establish a coordinate system registered to the cardiac anatomy. The atlas was applied to data contributed to the Cardiac Atlas Project from two independent studies which used different imaging protocols: steady state free precession (SSFP) and gradient recalled echo (GRE) cardiovascular magnetic resonance (CMR). Shape bias due to imaging protocol was corrected using an atlas-based transformation which was generated from a set of 46 volunteers who were imaged with both protocols. Shape bias between GRE and SSFP was regionally variable, and was effectively removed using the atlas-based transformation. Global mass and volume bias was also corrected by this method. Regional shape differences between cohorts were more statistically significant after removing regional artifacts due to imaging protocol bias. Bias arising from imaging protocol can be both global and regional in nature, and is effectively corrected using an atlas-based transformation, enabling direct comparison of regional wall motion abnormalities between cohorts acquired in separate studies.

  6. 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)

  7. 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.

  8. CMR Catalog Service for the Web

    Science.gov (United States)

    Newman, Doug; Mitchell, Andrew

    2016-01-01

    With the impending retirement of Global Change Master Directory (GCMD) Application Programming Interfaces (APIs) the Common Metadata Repository (CMR) was charged with providing a collection-level Catalog Service for the Web (CSW) that provided the same level of functionality as GCMD. This talk describes the capabilities of the CMR CSW API with particular reference to the support of the Committee on Earth Observation Satellites (CEOS) Working Group on Information Systems and Services (WGISS) Integrated Catalog (CWIC).

  9. Transfer learning improves supervised image segmentation across imaging protocols.

    Science.gov (United States)

    van Opbroek, Annegreet; Ikram, M Arfan; Vernooij, Meike W; de Bruijne, Marleen

    2015-05-01

    The variation between images obtained with different scanners or different imaging protocols presents a major challenge in automatic segmentation of biomedical images. This variation especially hampers the application of otherwise successful supervised-learning techniques which, in order to perform well, often require a large amount of labeled training data that is exactly representative of the target data. We therefore propose to use transfer learning for image segmentation. Transfer-learning techniques can cope with differences in distributions between training and target data, and therefore may improve performance over supervised learning for segmentation across scanners and scan protocols. We present four transfer classifiers that can train a classification scheme with only a small amount of representative training data, in addition to a larger amount of other training data with slightly different characteristics. The performance of the four transfer classifiers was compared to that of standard supervised classification on two magnetic resonance imaging brain-segmentation tasks with multi-site data: white matter, gray matter, and cerebrospinal fluid segmentation; and white-matter-/MS-lesion segmentation. The experiments showed that when there is only a small amount of representative training data available, transfer learning can greatly outperform common supervised-learning approaches, minimizing classification errors by up to 60%.

  10. Transfer learning improves supervised image segmentation across imaging protocols

    DEFF Research Database (Denmark)

    van Opbroek, Annegreet; Ikram, M. Arfan; Vernooij, Meike W.

    2015-01-01

    with slightly different characteristics. The performance of the four transfer classifiers was compared to that of standard supervised classification on two MRI brain-segmentation tasks with multi-site data: white matter, gray matter, and CSF segmentation; and white-matter- /MS-lesion segmentation......The variation between images obtained with different scanners or different imaging protocols presents a major challenge in automatic segmentation of biomedical images. This variation especially hampers the application of otherwise successful supervised-learning techniques which, in order to perform...... well, often require a large amount of labeled training data that is exactly representative of the target data. We therefore propose to use transfer learning for image segmentation. Transfer-learning techniques can cope with differences in distributions between training and target data, and therefore...

  11. The Combined Incremental Prognostic Value of LVEF, Late Gadolinium Enhancement, and Global Circumferential Strain Assessed by CMR.

    Science.gov (United States)

    Mordi, Ify; Bezerra, Hiram; Carrick, David; Tzemos, Nikolaos

    2015-05-01

    This study aimed to assess the incremental prognostic value of global circumferential strain (GCS), as measured using cardiac magnetic resonance (CMR) tagging, in addition to baseline clinical characteristics, left ventricular ejection fraction (LVEF), and late gadolinium enhancement (LGE), in the prediction of major adverse cardiovascular events (MACE) in an unselected cohort of patients. LVEF is a powerful predictor of mortality and is used for guiding treatment decisions. It is, however, subject to limitations. The value of GCS measured by CMR tagging in patients with suspected cardiac disease has not been fully explored despite its being considered as the gold standard noninvasive method of assessment of LV deformation. We prospectively evaluated data from 539 consecutive patients referred for CMR who underwent a CMR protocol that included cine imaging, tagging, and LGE. The primary endpoint was the prevalence of MACE, defined as a composite of all-cause mortality, heart failure-related hospitalization, and aborted sudden cardiac death. MACE occurred in 62 of 539 patients (11.5%) over a mean follow-up period of 2.2 years. History of ischemic heart disease (IHD) and beta-blocker use were both significant clinical predictors of adverse outcomes. All 3 CMR parameters were significant multivariate predictors of the primary outcome when added to significant clinical predictors (LVEF, hazard ratio [HR]: 0.96 [95% confidence interval [CI]: 0.94 to 0.99; p = 0.005]; presence of LGE, HR: 2.07 [95% CI: 1.03 to 4.14; p = 0.04]; GCS, HR: 1.11 [95% CI: 1.02 to 1.21; p = 0.041]). Global chi-square increased significantly with the addition of both LGE and GCS. Both the presence of LGE and reduced GCS had independent prognostic value in the overall cohort. Patients with LVEF ≥35% but LGE present and reduced GCS had a poor outcome similar to that in those with LVEF value. This measure could provide further risk stratification, especially in patients with mild LV impairment

  12. MR imaging diagnostic protocol for unilocular lesions of the jaw

    Directory of Open Access Journals (Sweden)

    Hironobu Konouchi

    2012-08-01

    Using our MR imaging diagnostic protocol to diagnose 31 cases, we obtained a positivity rate of 71.0%. The use of our MR imaging diagnostic protocol for unilocular lesions, which are especially difficult to differentiate by radiography, would improve the morphological and qualitative diagnosis of soft tissue lesions.

  13. Diagnostic performance of dark-blood T2-weighted CMR for evaluation of acute myocardial injury.

    Science.gov (United States)

    Srichai, Monvadi B; Lim, Ruth P; Lath, Narayan; Babb, James; Axel, Leon; Kim, Daniel

    2013-01-01

    We compared the image quality and diagnostic performance of 2 fat-suppression methods for black-blood T2-weighted fast spin-echo (FSE), which are as follows: (a) short T1 inversion recovery (STIR; FSE-STIR) and (b) spectral adiabatic inversion recovery (SPAIR; FSE-SPAIR), for detection of acute myocardial injury. Edema-sensitive T2-weighted FSE cardiac magnetic resonance (CMR) imaging is useful in detecting acute myocardial injury but may experience reduced myocardial signal and signal dropout. The SPAIR pulse aims to eliminate artifacts associated with the STIR pulse. A total of 65 consecutive patients referred for CMR evaluation of myocardial structure and function underwent FSE-STIR and FSE-SPAIR, in addition to cine and late gadolinium enhancement (LGE) CMR. T2-weighted FSE images were independently evaluated by 2 readers for image quality and artifacts (Likert scale of 1-5; best-worst) and presence of increased myocardial signal suggestive of edema. In addition, clinical CMR interpretation, incorporating all CMR sequences available, was recorded for comparison. Diagnostic performance of each T2-weighted sequence was measured using recent (T2, and wall motion. There was a statistically significant difference in sensitivity between the clinical interpretation and each of the T2-weighted sequences but not between each T2-weighted sequence. Although FSE-SPAIR demonstrated significantly improved image quality and decreased artifacts, isolated interpretations of each T2-weighted technique demonstrated high specificity but overall low sensitivity for the detection of myocardial injury, with no difference in accuracy between the techniques. However, real-world interpretation in combination with cine and LGE CMR methods significantly improves the overall sensitivity and diagnostic performance.

  14. 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

  15. 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

  16. Essential Structural and Functional Roles of the Cmr4 Subunit in RNA Cleavage by the Cmr CRISPR-Cas Complex

    Directory of Open Access Journals (Sweden)

    Nancy F. Ramia

    2014-12-01

    Full Text Available Summary: The Cmr complex is the multisubunit effector complex of the type III-B clustered regularly interspaced short palindromic repeats (CRISPR-Cas immune system. The Cmr complex recognizes a target RNA through base pairing with the integral CRISPR RNA (crRNA and cleaves the target at multiple regularly spaced locations within the complementary region. To understand the molecular basis of the function of this complex, we have assembled information from electron microscopic and X-ray crystallographic structural studies and mutagenesis of a complete Pyrococcus furiosus Cmr complex. Our findings reveal that four helically packed Cmr4 subunits, which make up the backbone of the Cmr complex, act as a platform to support crRNA binding and target RNA cleavage. Interestingly, we found a hook-like structural feature associated with Cmr4 that is likely the site of target RNA binding and cleavage. Our results also elucidate analogies in the mechanisms of crRNA and target molecule binding by the distinct Cmr type III-A and Cascade type I-E complexes. : Ramia et al. show that the helical core of the type III-B Cmr CRISPR-Cas effector complex, made up of multiple Cmr4 subunits, forms the platform for a corresponding number of cleavages of the target RNA. Comparison with the type I-E Cascade structure reveals strikingly similar mechanisms of crRNA and target binding.

  17. Imaging techniques and investigation protocols in pediatric emergency imaging

    International Nuclear Information System (INIS)

    Scharitzer, M.; Hoermann, M.; Puig, S.; Prokop, M.

    2002-01-01

    Paediatric emergencies demand a quick and efficient radiological investigation with special attention to specific adjustments related to patient age and radiation protection. Imaging modalities are improving rapidly and enable to diagnose childhood diseases and injuries more quickly, accurately and safely. This article provides an overview of imaging techniques adjusted to the age of the child and an overview of imaging strategies of common paediatric emergencies. Optimising the imaging parameters (digital radiography, different screen-film systems, exposure specifications) allows for substantial reduction of radiation dose. Spiral- and multislice-CT reduce scan time and enable a considerable reduction of radiation exposure if scanning parameters (pitch setting, tube current) are properly adjusted. MRI is still mainly used for neurological or spinal emergencies despite the advent of fast imaging sequences. The radiologist's task is to select an appropriate imaging strategy according to expected differential diagnosis and to adjust the imaging techniques to the individual patient. (orig.) [de

  18. Use of cardiac magnetic resonance imaging to evaluate cardiac structure, function and fibrosis in children with infantile Pompe disease on enzyme replacement therapy.

    Science.gov (United States)

    Barker, Piers C A; Pasquali, Sara K; Darty, Stephen; Ing, Richard J; Li, Jennifer S; Kim, Raymond J; DeArmey, Stephanie; Kishnani, Priya S; Campbell, Michael J

    2010-12-01

    Pompe disease (acid α-glucosidase deficiency) is one of several lysosomal storage diseases amenable to treatment with enzyme replacement therapy (ERT). While echocardiography (echo) has been the standard method to evaluate the cardiac response to ERT, cardiac magnetic resonance imaging (CMR) has the advantage of a better tissue definition and characterization of myocardial fibrosis. However, CMR for Pompe disease is not frequently performed due to a high risk of sedation. We report the first use of CMR in a feasible protocol to quantify left ventricular (LV) mass, function, and the presence of myocardial fibrosis in the Pompe population. Children with Pompe disease on ERT were assessed with transthoracic echo and CMR over a 3 year period at a single institution. Echocardiography was performed using standard techniques without sedation. CMR was performed using retrospectively gated and real-time imaging, with and without sedation. LV mass indexed to body surface area (LVMI) and ejection fraction (EF) were measured by both echo and CMR, and evaluated for change over time. Myocardial fibrosis was assessed by CMR with delayed enhancement imaging 5-10 min after gadolinium contrast using single shot inversion recovery sequences with inversion time set to null the signal from normal myocardium. Seventeen CMR scans were successfully performed in 10 subjects with Pompe disease (median age at first CMR is 9 months, range 1-38 months, 80% male), with sedation only performed in 4 studies. There was a median interval of 5 months (range 0-34 months) from the start of ERT to first CMR (baseline). At baseline, the median indexed LVMI by CMR (140.0 g/m(2), range 43.8-334.0) tended to be lower than that assessed by echo (median 204.0 g/m(2), range 52.0-385.0), but did not reach statistical significance. At baseline, CMR EF was similar to that assessed by echo (55% vs. 55%). Overall, there was no significant decrease in CMR measured LVMI over time (CMR median LVMI at baseline 94 g

  19. T2-weighted imaging of the heart—A pictorial review

    International Nuclear Information System (INIS)

    Mirakhur, Anirudh; Anca, Nicoleta; Mikami, Yoko; Merchant, Naeem

    2013-01-01

    Spin-Echo techniques in cardiovascular magnetic resonance (CMR) have been used for decades, primarily to image cardiac anatomy. More recently, T2-weighted (T2W) imaging has seen an increased role in CMR protocols, especially in tissue characterization in acute myocardial processes. This article will review current methodologies of cardiac T2W acquisition and their limitations, as well as approach to both semi-quantitative and quantitative analyses. The appearance and utility of T2W imaging in a myriad of pathologic myocardial processes such as acute myocardial infarction, acute viral myocarditis, reversible stress-related cardiomyopathy, hypertrophic cardiomyopathy, and cardiac sarcoidosis, will also be discussed

  20. Motion compensated cine CMR of the fetal heart using radial undersampling and compressed sensing

    OpenAIRE

    Roy, Christopher W.; Seed, Mike; Kingdom, John C.; Macgowan, Christopher K.

    2017-01-01

    Background To develop and evaluate a reconstruction framework for high resolution time-resolved CMR of the fetal heart in the presence of motion. Methods Data were acquired using a golden angle radial trajectory in seven fetal subjects and reconstructed as real-time images to detect fetal movement. Data acquired during through-plane motion were discarded whereas in-plane motion was corrected. A fetal cardiac gating signal was extracted to sort the corrected data by cardiac phase, allowing rec...

  1. Feature tracking CMR reveals abnormal strain in preclinical arrhythmogenic right ventricular dysplasia/ cardiomyopathy: a multisoftware feasibility and clinical implementation study.

    Science.gov (United States)

    Bourfiss, Mimount; Vigneault, Davis M; Aliyari Ghasebeh, Mounes; Murray, Brittney; James, Cynthia A; Tichnell, Crystal; Mohamed Hoesein, Firdaus A; Zimmerman, Stefan L; Kamel, Ihab R; Calkins, Hugh; Tandri, Harikrishna; Velthuis, Birgitta K; Bluemke, David A; Te Riele, Anneline S J M

    2017-09-01

    Regional right ventricular (RV) dysfunction is the hallmark of Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C), but is currently only qualitatively evaluated in the clinical setting. Feature Tracking Cardiovascular Magnetic Resonance (FT-CMR) is a novel quantitative method that uses cine CMR to calculate strain values. However, most prior FT-CMR studies in ARVD/C have focused on global RV strain using different software methods, complicating implementation of FT-CMR in clinical practice. We aimed to assess the clinical value of global and regional strain using FT-CMR in ARVD/C and to determine differences between commercially available FT-CMR software packages. We analyzed cine CMR images of 110 subjects (39 overt ARVD/C [mutation+/phenotype+], 40 preclinical ARVD/C [mutation+/phenotype-] and 31 control) for global and regional (subtricuspid, anterior, apical) RV strain in the horizontal longitudinal axis using four FT-CMR software methods (Multimodality Tissue Tracking, TomTec, Medis and Circle Cardiovascular Imaging). Intersoftware agreement was assessed using Bland Altman plots. For global strain, all methods showed reduced strain in overt ARVD/C patients compared to control subjects (p  0.275). For regional strain, overt ARVD/C patients showed reduced strain compared to control subjects in all segments which reached statistical significance in the subtricuspid region for all software methods (p < 0.037), in the anterior wall for two methods (p < 0.005) and in the apex for one method (p = 0.012). Preclinical subjects showed abnormal subtricuspid strain compared to control subjects using one of the software methods (p = 0.009). Agreement between software methods for absolute strain values was low (Intraclass Correlation Coefficient = 0.373). Despite large intersoftware variability of FT-CMR derived strain values, all four software methods distinguished overt ARVD/C patients from control subjects by both global and subtricuspid

  2. Standardized food images : A photographing protocol and image database

    NARCIS (Netherlands)

    Charbonnier, Lisette; van Meer, Floor; van der Laan, Laura N.; Viergever, Max A.; Smeets, Paul A M

    2015-01-01

    The regulation of food intake has gained much research interest because of the current obesity epidemic. For research purposes, food images are a good and convenient alternative for real food because many dietary decisions are made based on the sight of foods. Food pictures are assumed to elicit

  3. Standardized food images: A photographing protocol and image database

    NARCIS (Netherlands)

    Charbonnier, L.; Meer, van der F.; Laan, van der L.N.; Viergever, M.A.; Smeets, P.A.M.

    2016-01-01

    The regulation of food intake has gained much research interest because of the current obesity epidemic. For research purposes, food images are a good and convenient alternative for real food because many dietary decisions are made based on the sight of foods. Food pictures are assumed to elicit

  4. Preoperative magnetic resonance imaging protocol for endoscopic cranial base image-guided surgery.

    Science.gov (United States)

    Grindle, Christopher R; Curry, Joseph M; Kang, Melissa D; Evans, James J; Rosen, Marc R

    2011-01-01

    Despite the increasing utilization of image-guided surgery, no radiology protocols for obtaining magnetic resonance (MR) imaging of adequate quality are available in the current literature. At our institution, more than 300 endonasal cranial base procedures including pituitary, extended pituitary, and other anterior skullbase procedures have been performed in the past 3 years. To facilitate and optimize preoperative evaluation and assessment, there was a need to develop a magnetic resonance protocol. Retrospective Technical Assessment was performed. Through a collaborative effort between the otolaryngology, neurosurgery, and neuroradiology departments at our institution, a skull base MR image-guided (IGS) protocol was developed with several ends in mind. First, it was necessary to generate diagnostic images useful for the more frequently seen pathologies to improve work flow and limit the expense and inefficiency of case specific MR studies. Second, it was necessary to generate sequences useful for IGS, preferably using sequences that best highlight that lesion. Currently, at our institution, all MR images used for IGS are obtained using this protocol as part of preoperative planning. The protocol that has been developed allows for thin cut precontrast and postcontrast axial cuts that can be used to plan intraoperative image guidance. It also obtains a thin cut T2 axial series that can be compiled separately for intraoperative imaging, or may be fused with computed tomographic images for combined modality. The outlined protocol obtains image sequences effective for diagnostic and operative purposes for image-guided surgery using both T1 and T2 sequences. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Study of the CMR compounds in hazardous wastes

    International Nuclear Information System (INIS)

    Chollot, A.

    2007-01-01

    In order to limit the exposure of workers to carcinogenic, mutagen and reproduction-toxic compounds (CMR) and to optimize the safety needs in the field of hazardous industrial wastes, the INRS has decided to complete its knowledge in doing a sectorial inquiry titled 'study of the CMR compounds contained in wastes'. This study allows to obtain data relative to hazardous wastes and to the presence of CMR compounds into these hazardous wastes. The first part of this study gives the methodology used for doing this inquiry. The results, gathered in databases, are presented in tables and in synthetic schemes. The last part gives operational propositions it could be important to adopt to improve and/or to develop safety approaches adapted to the CMR risk and, particularly the transfer of the good data to workers. (O.M.)

  6. High-resolution neutron powder-diffraction in CMR manganates

    Energy Technology Data Exchange (ETDEWEB)

    Suard, E; Radaelli, P G [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    Manganese-oxide materials have recently been the subject of renewed attention, due to the `colossal` magnetoresistance (CMR) displayed near the spin-ordering temperature T{sub c} by some of these compounds. CMR has been evidenced in at least three families of manganese oxides. In most cases, the CMR compounds behave as paramagnetic semiconductors at high temperatures, and as ferromagnetic metals below T{sub c}. The study of this metallization process has lead some theorists to challenge its traditional interpretation in terms of the so-called double-exchange mechanism, and to propose alternative scenarios in which the coupling of the charge carriers with the lattice plays a paramount role. Powder diffraction method, being at the forefront of CMR research is presented. (author). 4 refs.

  7. Achieving Sub-Second Search in the CMR

    Science.gov (United States)

    Gilman, J.; Baynes, K.; Pilone, D.; Mitchell, A. E.; Murphy, K. J.

    2014-12-01

    The Common Metadata Repository (CMR) is the next generation Earth Science Metadata catalog for NASA's Earth Observing data. It joins together the holdings from the EOS Clearing House (ECHO) and the Global Change Master Directory (GCMD), creating a unified, authoritative source for EOSDIS metadata. The CMR allows ingest in many different formats while providing consistent search behavior and retrieval in any supported format. Performance is a critical component of the CMR, ensuring improved data discovery and client interactivity. The CMR delivers sub-second search performance for any of the common query conditions (including spatial) across hundreds of millions of metadata granules. It also allows the addition of new metadata concepts such as visualizations, parameter metadata, and documentation. The CMR's goals presented many challenges. This talk will describe the CMR architecture, design, and innovations that were made to achieve its goals. This includes: * Architectural features like immutability and backpressure. * Data management techniques such as caching and parallel loading that give big performance gains. * Open Source and COTS tools like Elasticsearch search engine. * Adoption of Clojure, a functional programming language for the Java Virtual Machine. * Development of a custom spatial search plugin for Elasticsearch and why it was necessary. * Introduction of a unified model for metadata that maps every supported metadata format to a consistent domain model.

  8. Developing optimized CT scan protocols: Phantom measurements of image quality

    International Nuclear Information System (INIS)

    Zarb, Francis; Rainford, Louise; McEntee, Mark F.

    2011-01-01

    Purpose: The increasing frequency of computerized tomography (CT) examinations is well documented, leading to concern about potential radiation risks for patients. However, the consequences of not performing the CT examination and missing injuries and disease are potentially serious, impacting upon correct patient management. The ALARA principle of dose optimization must be employed for all justified CT examinations. Dose indicators displayed on the CT console as either CT dose index (CTDI) and/or dose length product (DLP), are used to indicate dose and can quantify improvements achieved through optimization. Key scan parameters contributing to dose have been identified in previous literature and in previous work by our group. The aim of this study was to optimize the scan parameters of mA; kV and pitch, whilst maintaining image quality and reducing dose. This research was conducted using psychophysical image quality measurements on a CT quality assurance (QA) phantom establishing the impact of dose optimization on image quality parameters. Method: Current CT scan parameters for head (posterior fossa and cerebrum), abdomen and chest examinations were collected from 57% of CT suites available nationally in Malta (n = 4). Current scan protocols were used to image a Catphan 600 CT QA phantom whereby image quality was assessed. Each scan parameter: mA; kV and pitch were systematically reduced until the contrast resolution (CR), spatial resolution (SR) and noise were significantly lowered. The Catphan 600 images, produced by the range of protocols, were evaluated by 2 expert observers assessing CR, SR and noise. The protocol considered as the optimization threshold was just above the setting that resulted in a significant reduction in CR and noise but not affecting SR at the 95% confidence interval. Results: The limit of optimization threshold was determined for each CT suite. Employing optimized parameters, CTDI and DLP were both significantly reduced (p ≤ 0.001) by

  9. Atomic and microstructure of CMR materials

    International Nuclear Information System (INIS)

    Van Tendeloo, G.; Lebedev, O.I.; Amelinckx, S.

    2000-01-01

    The local structure of bulk and thin films of different perovskite-based CMR materials has been studied by high-resolution electron microscopy. The structure of Ln 1-x A x MnO 3 is not only a function of temperature and A-doping, but also of the thickness of the film. Evidence is produced for a slight monoclinic distortion at room temperature in most Ln 1-x A x MnO 3 compounds. For epitaxial La 0.7 Sr 0.3 MnO 3 (LSMO) films on a LaAlO 3 (0 0 1) the evolution of stress in the film is studied as a function of film thickness and thermal treatment. Close to the interface both film and substrate are elastically strained in opposite sense such that the interface is perfectly coherent for thin films not exceeding 30-35 nm. In thicker films the stress is partially relieved after annealing by the formation of misfit dislocations with an edge character. Thin films of La 1-x Ca x MnO 3 on a SrTiO 3 substrate, exhibit a remarkable microstructure. In direct contact with the SrTiO 3 substrate a thin featureless perfectly coherent La 1-x Ca x MnO 3 layer is formed. Subsequently, on top of this first layer a second thicker layer is deposited; it has a columnar microstructure. These columns, parallel to the interface normal, are in fact prismatic anti-phase domains. Their formation is attributed to the introduction of chemical faults during the film growth process. Islands of rocksalt-type MnO structure, nucleated within the regular La-O layer of the LCMO structure, initiate the formation of the prismatic anti-phase domains. Models of the domain boundaries and of the interface film/substrate are proposed. A growth mechanism for the domain structure is suggested

  10. Detection and characteristics of microvascular obstruction in reperfused acute myocardial infarction using an optimized protocol for contrast-enhanced cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bekkers, Sebastiaan C.A.M.; Gorgels, Anton P.M.; Passos, Valeria Lima; Waltenberger, Johannes; Crijns, Harry J.G.M.; Schalla, Simon [Maastricht University Medical Center, Department of Cardiology, P. Debyelaan 25, PO Box 5800, Maastricht (Netherlands); Backes, Walter H.; Snoep, Gabriel [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, PO Box 5800, Maastricht (Netherlands); Kim, Raymond J. [Duke University Medical Center, Duke Cardiovascular Magnetic Resonance Center, PO Box 3934, Durham, NC (United States)

    2009-12-15

    Several cardiovascular magnetic resonance imaging (CMR) techniques are used to detect microvascular obstruction (MVO) after acute myocardial infarction (AMI). To determine the prevalence of MVO and gain more insight into the dynamic changes in appearance of MVO, we studied 84 consecutive patients with a reperfused AMI on average 5 and 104 days after admission, using an optimised single breath-hold 3D inversion recovery gradient echo pulse sequence (IR-GRE) protocol. Early MVO (2 min post-contrast) was detected in 53 patients (63%) and late MVO (10 min post-contrast) in 45 patients (54%; p = 0.008). The extent of MVO decreased from early to late imaging (4.3 {+-} 3.2% vs. 1.8 {+-} 1.8%, p < 0.001) and showed a heterogeneous pattern. At baseline, patients without MVO (early and late) had a higher left ventricular ejection fraction (LVEF) than patients with persistent late MVO (56 {+-} 7% vs. 48 {+-} 7%, p < 0.001) and LVEF was intermediate in patients with early MVO but late MVO disappearance (54 {+-} 6%). During follow-up, LVEF improved in all three subgroups but remained intermediate in patients with late MVO disappearance. This optimised single breath-hold 3D IR-GRE technique for imaging MVO early and late after contrast administration is fast, accurate and allows detection of patients with intermediate remodelling at follow-up. (orig.)

  11. Comparison of dose and image quality in protocols abdominal CT using high an low KVP

    International Nuclear Information System (INIS)

    Mas Munoz, I.; Alejo Luque, L.; Corredoira Silva, E.; Sanchez Munoz, F. J.; Serrada Hierro, A.

    2013-01-01

    This paper compares quantitatively low kV Protocol with the conventional Protocol of abdomen, analysing the image quality with objective physical parameters and calculating the corresponding dummy dose reduction. (Author)

  12. Image quality comparison between single energy and dual energy CT protocols for hepatic imaging

    International Nuclear Information System (INIS)

    Yao, Yuan; Pelc, Norbert J.; Ng, Joshua M.; Megibow, Alec J.

    2016-01-01

    Purpose: Multi-detector computed tomography (MDCT) enables volumetric scans in a single breath hold and is clinically useful for hepatic imaging. For simple tasks, conventional single energy (SE) computed tomography (CT) images acquired at the optimal tube potential are known to have better quality than dual energy (DE) blended images. However, liver imaging is complex and often requires imaging of both structures containing iodinated contrast media, where atomic number differences are the primary contrast mechanism, and other structures, where density differences are the primary contrast mechanism. Hence it is conceivable that the broad spectrum used in a dual energy acquisition may be an advantage. In this work we are interested in comparing these two imaging strategies at equal-dose and more complex settings. Methods: We developed numerical anthropomorphic phantoms to mimic realistic clinical CT scans for medium size and large size patients. MDCT images based on the defined phantoms were simulated using various SE and DE protocols at pre- and post-contrast stages. For SE CT, images from 60 kVp through 140 with 10 kVp steps were considered; for DE CT, both 80/140 and 100/140 kVp scans were simulated and linearly blended at the optimal weights. To make a fair comparison, the mAs of each scan was adjusted to match the reference radiation dose (120 kVp, 200 mAs for medium size patients and 140 kVp, 400 mAs for large size patients). Contrast-to-noise ratio (CNR) of liver against other soft tissues was used to evaluate and compare the SE and DE protocols, and multiple pre- and post-contrasted liver-tissue pairs were used to define a composite CNR. To help validate the simulation results, we conducted a small clinical study. Eighty-five 120 kVp images and 81 blended 80/140 kVp images were collected and compared through both quantitative image quality analysis and an observer study. Results: In the simulation study, we found that the CNR of pre-contrast SE image mostly

  13. Crystallization and preliminary X-ray diffraction analysis of the Cmr2–Cmr3 subcomplex in the CRISPR–Cas RNA-silencing effector complex

    Energy Technology Data Exchange (ETDEWEB)

    Osawa, Takuo; Inanaga, Hideko; Numata, Tomoyuki [National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba-shi, Ibaraki 305-8566 (Japan)

    2013-04-30

    The Cmr2–Cmr3 subcomplex from P. furiosus was co-crystallized with 3′-AMP. X-ray diffraction data for the crystals were collected to 2.6 Å resolution using a synchrotron-radiation source. Clustered, regularly interspaced, short palindromic repeat (CRISPR) loci, found in prokaryotes, are transcribed to produce CRISPR RNAs (crRNAs). The Cmr proteins (Cmr1–6) and crRNA form a ribonucleoprotein complex that degrades target RNAs derived from invading genetic elements. Cmr2dHD, a Cmr2 variant lacking the N-terminal putative HD nuclease domain, and Cmr3 were co-expressed in Escherichia coli cells and co-purified as a complex. The Cmr2dHD–Cmr3 complex was co-crystallized with 3′-AMP by the vapour-diffusion method. The crystals diffracted to 2.6 Å resolution using synchrotron radiation at the Photon Factory. The crystals belonged to the orthorhombic space group I222, with unit-cell parameters a = 103.9, b = 136.7, c = 192.0 Å. The asymmetric unit of the crystals is expected to contain one Cmr2dHD–Cmr3 complex with a Matthews coefficient of 3.0 Å{sup 3} Da{sup −1} and a solvent content of 59%.

  14. Crystallization and preliminary X-ray diffraction analysis of the Cmr2–Cmr3 subcomplex in the CRISPR–Cas RNA-silencing effector complex

    International Nuclear Information System (INIS)

    Osawa, Takuo; Inanaga, Hideko; Numata, Tomoyuki

    2013-01-01

    The Cmr2–Cmr3 subcomplex from P. furiosus was co-crystallized with 3′-AMP. X-ray diffraction data for the crystals were collected to 2.6 Å resolution using a synchrotron-radiation source. Clustered, regularly interspaced, short palindromic repeat (CRISPR) loci, found in prokaryotes, are transcribed to produce CRISPR RNAs (crRNAs). The Cmr proteins (Cmr1–6) and crRNA form a ribonucleoprotein complex that degrades target RNAs derived from invading genetic elements. Cmr2dHD, a Cmr2 variant lacking the N-terminal putative HD nuclease domain, and Cmr3 were co-expressed in Escherichia coli cells and co-purified as a complex. The Cmr2dHD–Cmr3 complex was co-crystallized with 3′-AMP by the vapour-diffusion method. The crystals diffracted to 2.6 Å resolution using synchrotron radiation at the Photon Factory. The crystals belonged to the orthorhombic space group I222, with unit-cell parameters a = 103.9, b = 136.7, c = 192.0 Å. The asymmetric unit of the crystals is expected to contain one Cmr2dHD–Cmr3 complex with a Matthews coefficient of 3.0 Å 3 Da −1 and a solvent content of 59%

  15. Evaluation of image quality and dose in renal colic: comparison of different spiral-CT protocols

    International Nuclear Information System (INIS)

    Rimondini, A.; Mucelli, R.P.; Dalla Palma, L.; De Denaro, M.; Bregant, P.

    2001-01-01

    The aim of this study was to test different technical spiral-CT parameters to obtain optimal image quality with reduced X-ray dose. Images were acquired with a spiral-CT system Philips Tomoscan AVE1, using 250 mA, 120 kV, and 1-s rotational time. Three protocols were tested: protocol A with 5-mm thickness, pitch 1.6, slice reconstruction every 2.5 mm; protocol B with 3-mm thickness, pitch 1.6, slice reconstruction every 1.5 mm; and protocol C with 3-mm thickness, pitch 2, slice reconstruction every 1.5 mm. Two phantoms were employed to evaluate the image quality. Axial images were acquired, then sagittal and coronal images were reconstructed. Finally, the absorbed X-ray dose for each protocol was measured. Regarding image quality, 5-mm-thick images (protocol A) showed greater spatial resolution and lower noise compared with 3-mm-thick images (protocols B and C) on the axial plane; 3-mm reconstructed sagittal and coronal images (protocols B and C) showed an improved image quality compared with 5-mm reformatted images (protocol A). Concerning X-ray dose, the mean dose was: protocol A 19.6±0.8 mGy; protocol B 14.4±0.6 mGy; protocol C 12.5±1.0 mGy. Our study supports the use of thin slices (3 mm) combined with pitch of 1.6 or 2 in renal colic for X-ray dose reduction to the patient and good image quality. (orig.)

  16. The Possibilities of Installing Electronic CMR Waybill in Road Transport Sector

    Directory of Open Access Journals (Sweden)

    Arvydas Baublys

    2016-02-01

    Full Text Available In the article opportunities of changing paper CMR waybill into electronic are analysed, whereas the paper CMR waybill does not guarantee operational information exchange between participants of logistics chain components in road transport. Due to this reason use ofelectronic CMR waybill becomes more and more important. According to researches done by article authors, the article submitted the limitations of paper CMR waybill, benefits of electronic CMR waybill, concept model of implementing electronic CMR waybill and application possibilities of supply chain components.

  17. Comparison of two imaging protocols for acute stroke: unenhanced cranial CT versus a multimodality cranial CT protocol with perfusion imaging

    International Nuclear Information System (INIS)

    Langer, R. D.; Gorkom, K. Neidl van.; Kaabi, Ho Al.; Torab, F.; Czechowski, J.; Nagi, M.; Ashish, G. M.

    2007-01-01

    Full text: The aim of the study was to validate a multimodality cranial computed tomography (CCT) protocol for patients with acute stroke in the United Arab Emirates as a basic imaging procedure for a stroke unit. Therefore, a comparative study was conducted between two groups: retrospective, historical group 1 with early unenhanced CCT and prospective group 2 undergoing a multimodality CCT protocol. Follow-up unenhanced CCT >48 h served as gold standard in both groups. Group 1: Early unenhanced CCT of 50 patients were evaluated retrospectively, using Alberta Stroke Program Early CT Score, and compared with the definite infarction on follow-up CCT. Group 2: 50 patients underwent multimodality CCT (unenhanced CCT, perfusion studies: cerebral blood flow, cerebral blood volume, mean transit time and CT angiography) <8 h after clinical onset and follow-up studies. Modified National Institute of Health Stroke Scale was used clinically in both groups. Group 1 showed 38 men, 12 women, clinical onset 2-8 h before CCT and modified National Institute of Health Stroke Scale 0-28. Group 2 included 38 men, 12 women, onset 3-8 h before CCT, modified National Institute of Health Stroke Scale 0-28. Sensitivity was 58.3% in group 1 and 84.2% in group 2. Computed tomography angiography detected nine intracranial occlusions/stenoses. The higher sensitivity of the multimodality CCT protocol justifies its use as a basic diagnostic tool for the set-up of a first-stroke unit in the United Arab Emirates

  18. Comparison of exercise electrocardiography and stress perfusion CMR for the detection of coronary artery disease in women

    Directory of Open Access Journals (Sweden)

    Greulich Simon

    2012-06-01

    Full Text Available Abstract Background Exercise electrocardiography (ECG is frequently used in the work-up of patients with suspected coronary artery disease (CAD, however the accuracy is reduced in women. Cardiovascular magnetic resonance (CMR stress testing can accurately diagnose CAD in women. To date, a direct comparison of CMR to ECG has not been performed. Methods and results We prospectively enrolled 88 consecutive women with chest pain or other symptoms suggestive of CAD. Patients underwent a comprehensive clinical evaluation, exercise ECG, a CMR stress test including perfusion and infarct imaging, and x-ray coronary angiography (CA within 24 hours. CAD was defined as stenosis ≥70% on quantitative analysis of CA. Exercise ECG, CMR and CA was completed in 68 females (age 66.4 ± 8.8 years, number of CAD risk factors 3.5 ± 1.4. The prevalence of CAD on CA was 29%. The Duke treadmill score (DTS in the entire group was −3.0 ± 5.4 and was similar in those with and without CAD (−4.5 ± 5.8 and −2.4 ± 5.1; P = 0.12. Sensitivity, specificity and accuracy for CAD diagnosis was higher for CMR compared with exercise ECG (sensitivities 85% and 50%, P = 0.02, specificities 94% and 73%, P = 0.01, and accuracies 91% and 66%, P = 0.0007, respectively. Even after applying the DTS the accuracy of CMR was higher compared to exercise ECG (area under ROC curve 0.94 ± 0.03 vs 0.56 ± 0.07; P = 0.0001. Conclusions In women with intermediate-to-high risk for CAD who are able to exercise and have interpretable resting ECG, CMR stress perfusion imaging has higher accuracy for the detection of relevant obstruction of the epicardial coronaries when directly compared to exercise ECG.

  19. A CMR study of the effects of tissue edema and necrosis on left ventricular dyssynchrony in acute myocardial infarction: implications for cardiac resynchronization therapy

    Directory of Open Access Journals (Sweden)

    Manka Robert

    2012-07-01

    Full Text Available Abstract Background In acute myocardial infarction (AMI, both tissue necrosis and edema are present and both might be implicated in the development of intraventricular dyssynchrony. However, their relative contribution to transient dyssynchrony is not known. Cardiovascular magnetic resonance (CMR can detect necrosis and edema with high spatial resolution and it can quantify dyssynchrony by tagging techniques. Methods Patients with a first AMI underwent percutaneous coronary interventions (PCI of the infarct-related artery within 24 h of onset of chest pain. Within 5–7 days after the event and at 4 months, CMR was performed. The CMR protocol included the evaluation of intraventricular dyssynchrony by applying a novel 3D-tagging sequence to the left ventricle (LV yielding the CURE index (circumferential uniformity ratio estimate; 1 = complete synchrony. On T2-weighted images, edema was measured as high-signal (>2 SD above remote tissue along the LV mid-myocardial circumference on 3 short-axis images (% of circumference corresponding to the area-at-risk. In analogy, on late-gadolinium enhancement (LGE images, necrosis was quantified manually as percentage of LV mid-myocardial circumference on 3 short-axis images. Necrosis was also quantified on LGE images covering the entire LV (expressed as %LV mass. Finally, salvaged myocardium was calculated as the area-at-risk minus necrosis (expressed as % of LV circumference. Results After successful PCI (n = 22, 2 female, mean age: 57 ± 12y, peak troponin T was 20 ± 36ug/l and the LV ejection fraction on CMR was 41 ± 8%. Necrosis mass was 30 ± 10% and CURE was 0.91 ± 0.05. Edema was measured as 58 ± 14% of the LV circumference. In the acute phase, the extent of edema correlated with dyssynchrony (r2 = −0.63, p 2 = −0.19, p = 0.05. PCI resulted in salvaged myocardium of 27 ± 14%. LV dyssynchrony (=CURE decreased at 4 months from 0.91

  20. Should these potential CMR substances have been registered under REACH?

    DEFF Research Database (Denmark)

    Wedebye, Eva Bay; Nikolov, Nikolai Georgiev; Dybdahl, Marianne

    2013-01-01

    (Q)SAR models were applied to screen around 68,000 REACH pre-registered substances for CMR properties (carcinogenic, mutagenic or toxic to reproduction). Predictions from 14 relevant models were combined to reach overall calls for C, M and R. Combining predictions may reduce “noise” and increase...

  1. Comparison of monaural (CMR) and binaural (BMLD) masking release

    NARCIS (Netherlands)

    Par, van de S.L.J.D.E.; Kohlrausch, A.G.

    1998-01-01

    Release of masking for a sinusoidal signal of 5 kHz masked by a 25-Hz-wide noise band centered around 5 kHz was measured. The masking release was provided by a second noise band that was comodulated with the on-frequency masker band. For CMR configurations the second noise band was centered at 3 kHz

  2. Chemical and Metallurgy Research (CMR) Sample Tracking System Design Document

    International Nuclear Information System (INIS)

    Bargelski, C. J.; Berrett, D. E.

    1998-01-01

    The purpose of this document is to describe the system architecture of the Chemical and Metallurgy Research (CMR) Sample Tracking System at Los Alamos National Laboratory. During the course of the document observations are made concerning the objectives, constraints and limitations, technical approaches, and the technical deliverables

  3. Comparison of {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) in corticosteroid-naive patients with conduction system disease due to cardiac sarcoidosis

    Energy Technology Data Exchange (ETDEWEB)

    Ohira, Hiroshi; Birnie, David H.; Mc Ardle, Brian; Dick, Alexander; Klein, Ran; Renaud, Jennifer; DeKemp, Robert A.; Davies, Ross; Hessian, Renee; Liu, Peter; Nery, Pablo B. [University of Ottawa Heart Institute, Molecular Function and Imaging Program, National Cardiac PET Centre, Ottawa, ON (Canada); University of Ottawa Heart Institute, Arrhythmia Service, Division of Cardiology, Department of Medicine, Ottawa, ON (Canada); Pena, Elena; Dennie, Carole [The Ottawa Hospital, Medical Imaging Department, Ottawa, ON (Canada); University of Ottawa, Department of Radiology, Ottawa, ON (Canada); Bernick, Jordan; Wells, George A. [University of Ottawa Heart Institute, Cardiovascular Research Methods Center, Ottawa, ON (Canada); Leung, Eugene [The Ottawa Hospital, Division of Nuclear Medicine, Department of Medicine, Ottawa, Ontario (Canada); Yoshinaga, Keiichiro [Hokkaido University School of Medicine, Department of Molecular Imaging, Hokkaido (Japan); Tsujino, Ichizo; Sato, Takahiro; Nishimura, Masaharu [Hokkaido University School of Medicine, First Department of Medicine, Hokkaido (Japan); Manabe, Osamu; Tamaki, Nagara [Hokkaido University School of Medicine, Department of Nuclear Medicine, Hokkaido (Japan); Oyama-Manabe, Noriko [Hokkaido University Hospital, Diagnostic and Interventional Radiology, Hokkaido (Japan); Ruddy, Terrence D.; Beanlands, Rob S.B. [University of Ottawa Heart Institute, Molecular Function and Imaging Program, National Cardiac PET Centre, Ottawa, ON (Canada); University of Ottawa Heart Institute, Arrhythmia Service, Division of Cardiology, Department of Medicine, Ottawa, ON (Canada); The Ottawa Hospital, Medical Imaging Department, Ottawa, ON (Canada); University of Ottawa, Department of Radiology, Ottawa, ON (Canada); The Ottawa Hospital, Division of Nuclear Medicine, Department of Medicine, Ottawa, Ontario (Canada); Chow, Benjamin J.W. [University of Ottawa Heart Institute, Molecular Function and Imaging Program, National Cardiac PET Centre, Ottawa, ON (Canada); University of Ottawa Heart Institute, Arrhythmia Service, Division of Cardiology, Department of Medicine, Ottawa, ON (Canada); The Ottawa Hospital, Medical Imaging Department, Ottawa, ON (Canada); University of Ottawa, Department of Radiology, Ottawa, ON (Canada)

    2016-02-15

    Cardiac sarcoidosis (CS) is a cause of conduction system disease (CSD). {sup 18}F-Fluorodeoxyglucose-positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) are used for detection of CS. The relative diagnostic value of these has not been well studied. The aim was to compare these imaging modalities in this population. We recruited steroid-naive patients with newly diagnosed CSD due to CS. All CS patients underwent both imaging studies within 12 weeks of each other. Patients were classified into two groups: group A with chronic mild CSD (right bundle branch block and/or axis deviation), and group B with new-onset atrioventricular block (AVB, Mobitz type II or third-degree AVB). Thirty patients were included. Positive findings on both imaging studies were seen in 72 % of patients (13/18) in group A and in 58 % of patients (7/12) in group B. The remainder (28 %) of the patients in group A were positive only on CMR. Of the patients in group B, 8 % were positive only on CMR and 33 % were positive only on FDG PET. Patients in group A were more likely to be positive only on CMR, and patients in group B were more likely to be positive only on FDG PET (p = 0.02). Patients in group B positive only on FDG PET underwent CMR earlier relative to their symptomatology than patients positive only on CMR (median 7.0, IQR 1.5 - 34.3, vs. 72.0, IQR 25.0 - 79.5 days; p = 0.03). The number of positive FDG PET and CMR studies was different in patients with CSD depending on their clinical presentation. This study demonstrated that CMR can adequately detect cardiac involvement associated with chronic mild CSD. In patients presenting with new-onset AVB and a negative CMR study, FDG PET may be useful for detecting cardiac involvement due to CS. (orig.)

  4. Evaluation of imaging protocol for ECT based on CS image reconstruction algorithm

    International Nuclear Information System (INIS)

    Zhou Xiaolin; Yun Mingkai; Cao Xuexiang; Liu Shuangquan; Wang Lu; Huang Xianchao; Wei Long

    2014-01-01

    Single-photon emission computerized tomography and positron emission tomography are essential medical imaging tools, for which the sampling angle number and scan time should be carefully chosen to give a good compromise between image quality and radiopharmaceutical dose. In this study, the image quality of different acquisition protocols was evaluated via varied angle number and count number per angle with Monte Carlo simulation data. It was shown that, when similar imaging counts were used, the factor of acquisition counts was more important than that of the sampling number in emission computerized tomography. To further reduce the activity requirement and the scan duration, an iterative image reconstruction algorithm for limited-view and low-dose tomography based on compressed sensing theory has been developed. The total variation regulation was added to the reconstruction process to improve the signal to noise Ratio and reduce artifacts caused by the limited angle sampling. Maximization of the maximum likelihood of the estimated image and the measured data and minimization of the total variation of the image are alternatively implemented. By using this advanced algorithm, the reconstruction process is able to achieve image quality matching or exceed that of normal scans with only half of the injection radiopharmaceutical dose. (authors)

  5. Cardiac involvement in patients with Becker muscular dystrophy: new diagnostic and pathophysiological insights by a CMR approach

    Directory of Open Access Journals (Sweden)

    Thiene Gaetano

    2008-11-01

    Full Text Available Abstract Background Becker-Kiener muscular dystrophy (BMD represents an X-linked genetic disease associated with myocardial involvement potentially resulting in dilated cardiomyopathy (DCM. Early diagnosis of cardiac involvement may permit earlier institution of heart failure treatment and extend life span in these patients. Both echocardiography and nuclear imaging methods are capable of detecting later stages of cardiac involvement characterised by wall motion abnormalities. Cardiovascular magnetic resonance (CMR has the potential to detect cardiac involvement by depicting early scar formation that may appear before onset of wall motion abnormalities. Methods In a prospective two-center-study, 15 male patients with BMD (median age 37 years; range 11 years to 56 years underwent comprehensive neurological and cardiac evaluations including physical examination, echocardiography and CMR. A 16-segment model was applied for evaluation of regional wall motion abnormalities (rWMA. The CMR study included late gadolinium enhancement (LGE imaging with quantification of myocardial damage. Results Abnormal echocardiographic results were found in eight of 15 (53.3% patients with all of them demonstrating reduced left ventricular ejection fraction (LVEF and rWMA. CMR revealed abnormal findings in 12 of 15 (80.0% patients (p = 0.04 with 10 (66.6% having reduced LVEF (p = 0.16 and 9 (64.3% demonstrating rWMA (p = 0.38. Myocardial damage as assessed by LGE-imaging was detected in 11 of 15 (73.3% patients with a median myocardial damage extent of 13.0% (range 0 to 38.0%, an age-related increase and a typical subepicardial distribution pattern in the inferolateral wall. Ten patients (66.7% were in need of medical heart failure therapy based on CMR results. However, only 4 patients (26.7% were already taking medication based on clinical criteria (p = 0.009. Conclusion Cardiac involvement in patients with BMD is underdiagnosed by echocardiographic methods resulting

  6. [Multidisciplinary protocol for computed tomography imaging and angiographic embolization of splenic injury due to trauma: assessment of pre-protocol and post-protocol outcomes].

    Science.gov (United States)

    Koo, M; Sabaté, A; Magalló, P; García, M A; Domínguez, J; de Lama, M E; López, S

    2011-11-01

    To assess conservative treatment of splenic injury due to trauma, following a protocol for computed tomography (CT) and angiographic embolization. To quantify the predictive value of CT for detecting bleeding and need for embolization. The care protocol developed by the multidisciplinary team consisted of angiography with embolization of lesions revealed by contrast extravasation under CT as well as embolization of grade III-V injuries observed, or grade I-II injuries causing hemodynamic instability and/or need for blood transfusion. We collected data on demographic variables, injury severity score (ISS), angiographic findings, and injuries revealed by CT. Pre-protocol and post-protocol outcomes were compared. The sensitivity and specificity of CT findings were calculated for all patients who required angiographic embolization. Forty-four and 30 angiographies were performed in the pre- and post-protocol periods, respectively. The mean (SD) ISSs in the two periods were 25 (11) and 26 (12), respectively. A total of 24 (54%) embolizations were performed in the pre-protocol period and 28 (98%) after implementation of the protocol. Two and 7 embolizations involved the spleen in the 2 periods, respectively; abdominal laparotomies numbered 32 and 25, respectively, and 10 (31%) vs 4 (16%) splenectomies were performed. The specificity and sensitivity values for contrast extravasation found on CT and followed by embolization were 77.7% and 79.5%. The implementation of this multidisciplinary protocol using CT imaging and angiographic embolization led to a decrease in the number of splenectomies. The protocol allows us to take a more conservative treatment approach.

  7. Right coronary wall cmr in the older asymptomatic advance cohort: positive remodeling and associations with type 2 diabetes and coronary calcium

    Directory of Open Access Journals (Sweden)

    Courtney Brian K

    2010-12-01

    Full Text Available Abstract Background Coronary wall cardiovascular magnetic resonance (CMR is a promising noninvasive approach to assess subclinical atherosclerosis, but data are limited in subjects over 60 years old, who are at increased risk. The purpose of the study was to evaluate coronary wall CMR in an asymptomatic older cohort. Results Cross-sectional images of the proximal right coronary artery (RCA were acquired using spiral black-blood coronary CMR (0.7 mm resolution in 223 older, community-based patients without a history of cardiovascular disease (age 60-72 years old, 38% female. Coronary measurements (total vessel area, lumen area, wall area, and wall thickness had small intra- and inter-observer variabilities (r = 0.93~0.99, all p Conclusions Right coronary wall CMR in asymptomatic older subjects showed increased coronary atherosclerosis in subjects with type 2 diabetes as well as coronary calcification. Coronary wall CMR may contribute to the noninvasive assessment of subclinical coronary atherosclerosis in older, at-risk patient groups.

  8. Navigator-gated 3D blood oxygen level-dependent CMR at 3.0-T for detection of stress-induced myocardial ischemic reactions.

    Science.gov (United States)

    Jahnke, Cosima; Gebker, Rolf; Manka, Robert; Schnackenburg, Bernhard; Fleck, Eckart; Paetsch, Ingo

    2010-04-01

    This study determined the value of navigator-gated 3-dimensional blood oxygen level-dependent (BOLD) cardiac magnetic resonance (CMR) at 3.0-T for the detection of stress-induced myocardial ischemic reactions. Although BOLD CMR has been introduced for characterization of myocardial oxygenation status, previously reported CMR approaches suffered from a low signal-to-noise ratio and motion-related artifacts with impaired image quality and a limited diagnostic value in initial patient studies. Fifty patients with suspected or known coronary artery disease underwent CMR at 3.0-T followed by invasive X-ray angiography within 48 h. Three-dimensional BOLD images were acquired during free breathing with full coverage of the left ventricle in a short-axis orientation. The BOLD imaging was performed at rest and under adenosine stress, followed by stress and rest first-pass perfusion and delayed enhancement imaging. Quantitative coronary X-ray angiography (QCA) was used for coronary stenosis definition (diameter reduction > or =50%). The BOLD and first-pass perfusion images were semiquantitatively evaluated (for BOLD imaging, signal intensity differences between stress and rest [DeltaSI]; for perfusion imaging, myocardial perfusion reserve index [MPRI]). The image quality of BOLD CMR at rest and during adenosine stress was considered good to excellent in 90% and 84% of the patients, respectively. The DeltaSI measurements differed significantly between normal myocardium, myocardium supplied by a stenotic coronary artery, and infarcted myocardium (p exogenous contrast-enhancement studies. Copyright 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  9. The Role of Clinical Cardiac Magnetic Resonance Imaging in China: Current Status and the Future

    Directory of Open Access Journals (Sweden)

    Shi Chen, MD

    2016-12-01

    Full Text Available Cardiac magnetic resonance (CMR imaging plays an important role in the diagnosis and management of cardiovascular diseases. The state-of-the-art CMR imaging has many advantages in cardiac imaging, including excellent spatial and temporal resolution, unrestricted imaging field, no exposure to ionizing radiation, excellent tissue contrast, and unique myocardial tissue characterization. Clinical CMR imaging is used during the cardiovascular diagnostic workup in the United States and some European countries. Use of CMR imaging is emerging in hospitals in China and has a promising future. This review briefly describes the real-world clinical application of CMR imaging in China and discuss obstacles for its future development.

  10. Brain regions involved in voluntary movements as revealed by radioisotopic mapping of CBF or CMR-glucose changes

    DEFF Research Database (Denmark)

    Lassen, N A; Ingvar, D H

    1990-01-01

    Mapping of cortical and subcortical grey matter active during voluntary movements by means of measurements of local increases of CBF or CMR-Glucose is reviewed. Most of the studies concern observations in man during hand movements using the intracarotid Xenon-133 injection technique, an approach...... that only allows to image the cortex of the hemisphere on one side (the injected side) of the brain. The results show that simple static or repetitive movements mainly activate the contralateral primary hand area (MI and SI); complex preprogrammed or spontaneous purposeful movements the supplementary motor...... area SMA on both sides increase in CBF/CMR-glucose and even internally ("mentally") going through the trained movements, causes such changes; complex purposeful movements also activate the premotor cortex, a response that is bilateral with greatest response contralaterally. Studies in patients...

  11. Diagnostic and Prognostic Value of CMR T1-Mapping in Patients With Heart Failure and Preserved Ejection Fraction.

    Science.gov (United States)

    Rommel, Karl-Philipp; Lücke, Christian; Lurz, Philipp

    2017-10-01

    Heart failure with preserved ejection fraction (HFpEF) presents a major challenge in modern cardiology. Although this syndrome is of increasing prevalence and is associated with unfavorable outcomes, treatment trials have failed to establish effective therapies. Currently, solutions to this dilemma are being investigated, including categorizing and characterizing patients more diversely to individualize treatment. In this regard, new imaging techniques might provide important information. Diastolic dysfunction is a diagnostic and pathophysiological cornerstone in HFpEF and is believed to be caused by systemic inflammation with the development of interstitial myocardial fibrosis and myocardial stiffening. Cardiac magnetic resonance (CMR) T 1 -mapping is a novel tool, which allows noninvasive quantification of the extracellular space and diffuse myocardial fibrosis. This review provides an overview of the potential of myocardial tissue characterization with CMR T 1 mapping in HFpEF patients, outlining its diagnostic and prognostic implications and discussing future directions. We conclude that CMR T 1 mapping is potentially an effective tool for patient characterization in large-scale epidemiological, diagnostic, and therapeutic HFpEF trials beyond traditional imaging parameters. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  12. A review of imaging protocols for suspected skeletal dysplasia and a proposal for standardisation

    International Nuclear Information System (INIS)

    Watson, Sarah G.; Calder, Alistair D.; Offiah, Amaka C.; Negus, Samantha

    2015-01-01

    Expert radiology opinions are often requested to aid diagnosis of skeletal dysplasias or dysostoses, but due to variability in the imaging protocols used at different centres the views presented may be considered inadequate or incomplete resulting in diagnostic delays and increased patient and family anxiety. We propose the introduction of a standardised protocol that may be adapted in certain specific situations. (orig.)

  13. A review of imaging protocols for suspected skeletal dysplasia and a proposal for standardisation

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Sarah G. [Royal Surrey County Hospital, Department of Radiology, Surrey (United Kingdom); Calder, Alistair D. [Great Ormond Street Hospital for Children, NHS Foundation Trust, Department of Radiology, London (United Kingdom); Offiah, Amaka C. [Sheffield Children' s NHS Foundation Trust, The University of Sheffield Academic Unit of Child Health, Sheffield (United Kingdom); Negus, Samantha [St George' s Hospital, Department of Radiology, London (United Kingdom)

    2015-11-15

    Expert radiology opinions are often requested to aid diagnosis of skeletal dysplasias or dysostoses, but due to variability in the imaging protocols used at different centres the views presented may be considered inadequate or incomplete resulting in diagnostic delays and increased patient and family anxiety. We propose the introduction of a standardised protocol that may be adapted in certain specific situations. (orig.)

  14. The preparation of Drosophila embryos for live-imaging using the hanging drop protocol.

    Science.gov (United States)

    Reed, Bruce H; McMillan, Stephanie C; Chaudhary, Roopali

    2009-03-13

    Green fluorescent protein (GFP)-based timelapse live-imaging is a powerful technique for studying the genetic regulation of dynamic processes such as tissue morphogenesis, cell-cell adhesion, or cell death. Drosophila embryos expressing GFP are readily imaged using either stereoscopic or confocal microscopy. A goal of any live-imaging protocol is to minimize detrimental effects such as dehydration and hypoxia. Previous protocols for preparing Drosophila embryos for live-imaging analysis have involved placing dechorionated embryos in halocarbon oil and sandwiching them between a halocarbon gas-permeable membrane and a coverslip. The introduction of compression through mounting embryos in this manner represents an undesirable complication for any biomechanical-based analysis of morphogenesis. Our method, which we call the hanging drop protocol, results in excellent viability of embryos during live imaging and does not require that embryos be compressed. Briefly, the hanging drop protocol involves the placement of embryos in a drop of halocarbon oil that is suspended from a coverslip, which is, in turn, fixed in position over a humid chamber. In addition to providing gas exchange and preventing dehydration, this arrangement takes advantage of the buoyancy of embryos in halocarbon oil to prevent them from drifting out of position during timelapse acquisition. This video describes in detail how to collect and prepare Drosophila embryos for live imaging using the hanging drop protocol. This protocol is suitable for imaging dechorionated embryos using stereomicroscopy or any upright compound fluorescence microscope.

  15. SU-E-I-68: Practical Considerations On Implementation of the Image Gently Pediatric CT Protocols

    International Nuclear Information System (INIS)

    Zhang, J; Adams, C; Lumby, C; Dillon, J; Woods, E; Richer, E

    2014-01-01

    Purpose: One limitation associated with the Image Gently pediatric CT protocols is practical implementation of the recommended manual techniques. Inconsistency as a result of different practice is a possibility among technologist. An additional concern is the added risk of data error that would result in over or underexposure. The Automatic Exposure Control (AEC) features automatically reduce radiation for children. However, they do not work efficiently for the patients of very small size and relative large size. This study aims to implement the Image Gently pediatric CT protocols in the practical setting while maintaining the use of AEC features for pediatric patients of varying size. Methods: Anthropomorphological abdomen phantoms were scanned in a CT scanner using the Image Gently pediatric protocols, the AEC technique with a fixed adult baseline, and automatic protocols with various baselines. The baselines were adjusted corresponding to patient age, weight and posterioranterior thickness to match the Image Gently pediatric CT manual techniques. CTDIvol was recorded for each examination. Image noise was measured and recorded for image quality comparison. Clinical images were evaluated by pediatric radiologists. Results: By adjusting vendor default baselines used in the automatic techniques, radiation dose and image quality can match those of the Image Gently manual techniques. In practice, this can be achieved by dividing pediatric patients into three major groups for technologist reference: infant, small child, and large child. Further division can be done but will increase the number of CT protocols. For each group, AEC can efficiently adjust acquisition techniques for children. This implementation significantly overcomes the limitation of the Image Gently manual techniques. Conclusion: Considering the effectiveness in clinical practice, Image Gently Pediatric CT protocols can be implemented in accordance with AEC techniques, with adjusted baselines, to

  16. Advanced CUBIC protocols for whole-brain and whole-body clearing and imaging.

    Science.gov (United States)

    Susaki, Etsuo A; Tainaka, Kazuki; Perrin, Dimitri; Yukinaga, Hiroko; Kuno, Akihiro; Ueda, Hiroki R

    2015-11-01

    Here we describe a protocol for advanced CUBIC (Clear, Unobstructed Brain/Body Imaging Cocktails and Computational analysis). The CUBIC protocol enables simple and efficient organ clearing, rapid imaging by light-sheet microscopy and quantitative imaging analysis of multiple samples. The organ or body is cleared by immersion for 1-14 d, with the exact time required dependent on the sample type and the experimental purposes. A single imaging set can be completed in 30-60 min. Image processing and analysis can take whole-brain neural activities at single-cell resolution using Arc-dVenus transgenic (Tg) mice. CUBIC informatics calculated the Venus signal subtraction, comparing different brains at a whole-organ scale. These protocols provide a platform for organism-level systems biology by comprehensively detecting cells in a whole organ or body.

  17. Recurrence of Ewing sarcoma: Is detection by imaging follow-up protocol associated with survival advantage?

    NARCIS (Netherlands)

    Heinemann, Melina; Ranft, Andreas; Langer, Thorsten; Jürgens, Herbert; Kreyer, Justus; Vieth, Volker; Schäfers, Michael; Weckesser, Matthias; Simon, Thorsten; Hassenpflug, Wolf; Corbacioglu, Selim; Bielack, Stefan; Mayer-Steinacker, Regina; Kühne, Thomas; van den Berg, Henk; Gelderblom, Hans; Bauer, Sebastian; Stegger, Lars; Dirksen, Uta

    2018-01-01

    The Cooperative Ewing Sarcoma Study and the Late Effects Surveillance System of the Society for Paediatric Oncology and Haematology recommend a structured follow-up imaging protocol (FUIP) for patients with Ewing sarcoma (EwS) with decreasing frequency of imaging over the first 5 years. The present

  18. 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.

  19. Cochlear implant tailored imaging protocol: What clinicians need to know

    Directory of Open Access Journals (Sweden)

    Tougan Taha

    2015-03-01

    Clinical relevance/application: SNHL is a malfunction of the inner ear, vestibulocochlear nerve or central auditory pathway. Imaging helps to establish treatment regimens that improve auditory function.

  20. Evaluation of image-guidance protocols in the treatment of head and neck cancers

    International Nuclear Information System (INIS)

    Zeidan, Omar A.; Langen, Katja M.; Meeks, Sanford L.; Manon, Rafael R.; Wagner, Thomas H.; Willoughby, Twyla R.; Jenkins, D. Wayne; Kupelian, Patrick A.

    2007-01-01

    Purpose: The aim of this study was to assess the residual setup error of different image-guidance (IG) protocols in the alignment of patients with head and neck cancer. The protocols differ in the percentage of treatment fractions that are associated with image guidance. Using data from patients who were treated with daily IG, the residual setup errors for several different protocols are retrospectively calculated. Methods and Materials: Alignment data from 24 patients (802 fractions) treated with daily IG on a helical tomotherapy unit were analyzed. The difference between the daily setup correction and the setup correction that would have been made according to a specific protocol was used to calculate the residual setup errors for each protocol. Results: The different protocols are generally effective in reducing systematic setup errors. Random setup errors are generally not reduced for fractions that are not image guided. As a consequence, if every other treatment is image guided, still about 11% of all treatments (IG and not IG) are subject to three-dimensional setup errors of at least 5 mm. This frequency increases to about 29% if setup errors >3 mm are scored. For various protocols that require 15% to 31% of the treatments to be image guided, from 50% to 60% and from 26% to 31% of all fractions are subject to setup errors >3 mm and >5 mm, respectively. Conclusion: Residual setup errors reduce with increasing frequency of IG during the course of external-beam radiotherapy for head-and-neck cancer patients. The inability to reduce random setup errors for fractions that are not image guided results in notable residual setup errors

  1. Automatic spectral imaging protocol selection and iterative reconstruction in abdominal CT with reduced contrast agent dose: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Peijie; Liu, Jie; Chai, Yaru; Yan, Xiaopeng; Gao, Jianbo; Dong, Junqiang [The First Affiliated Hospital of Zhengzhou University, Department of Radiology, Zhengzhou, Henan Province (China)

    2017-01-15

    To evaluate the feasibility, image quality, and radiation dose of automatic spectral imaging protocol selection (ASIS) and adaptive statistical iterative reconstruction (ASIR) with reduced contrast agent dose in abdominal multiphase CT. One hundred and sixty patients were randomly divided into two scan protocols (n = 80) each; protocol A, 120 kVp/450 mgI/kg, filtered back projection algorithm (FBP); protocol B, spectral CT imaging with ASIS and 40 to 70 keV monochromatic images generated per 300 mgI/kg, ASIR algorithm. Quantitative parameters (image noise and contrast-to-noise ratios [CNRs]) and qualitative visual parameters (image noise, small structures, organ enhancement, and overall image quality) were compared. Monochromatic images at 50 keV and 60 keV provided similar or lower image noise, but higher contrast and overall image quality as compared with 120-kVp images. Despite the higher image noise, 40-keV images showed similar overall image quality compared to 120-kVp images. Radiation dose did not differ between the two protocols, while contrast agent dose in protocol B was reduced by 33 %. Application of ASIR and ASIS to monochromatic imaging from 40 to 60 keV allowed contrast agent dose reduction with adequate image quality and without increasing radiation dose compared to 120 kVp with FBP. (orig.)

  2. Automatic spectral imaging protocol selection and iterative reconstruction in abdominal CT with reduced contrast agent dose: initial experience

    International Nuclear Information System (INIS)

    Lv, Peijie; Liu, Jie; Chai, Yaru; Yan, Xiaopeng; Gao, Jianbo; Dong, Junqiang

    2017-01-01

    To evaluate the feasibility, image quality, and radiation dose of automatic spectral imaging protocol selection (ASIS) and adaptive statistical iterative reconstruction (ASIR) with reduced contrast agent dose in abdominal multiphase CT. One hundred and sixty patients were randomly divided into two scan protocols (n = 80) each; protocol A, 120 kVp/450 mgI/kg, filtered back projection algorithm (FBP); protocol B, spectral CT imaging with ASIS and 40 to 70 keV monochromatic images generated per 300 mgI/kg, ASIR algorithm. Quantitative parameters (image noise and contrast-to-noise ratios [CNRs]) and qualitative visual parameters (image noise, small structures, organ enhancement, and overall image quality) were compared. Monochromatic images at 50 keV and 60 keV provided similar or lower image noise, but higher contrast and overall image quality as compared with 120-kVp images. Despite the higher image noise, 40-keV images showed similar overall image quality compared to 120-kVp images. Radiation dose did not differ between the two protocols, while contrast agent dose in protocol B was reduced by 33 %. Application of ASIR and ASIS to monochromatic imaging from 40 to 60 keV allowed contrast agent dose reduction with adequate image quality and without increasing radiation dose compared to 120 kVp with FBP. (orig.)

  3. Crystallization and preliminary X-ray diffraction analysis of the CRISPR-Cas RNA-silencing Cmr complex.

    Science.gov (United States)

    Osawa, Takuo; Inanaga, Hideko; Numata, Tomoyuki

    2015-06-01

    Clustered regularly interspaced short palindromic repeat (CRISPR)-derived RNA (crRNA) and CRISPR-associated (Cas) proteins constitute a prokaryotic adaptive immune system (CRISPR-Cas system) that targets and degrades invading genetic elements. The type III-B CRISPR-Cas Cmr complex, composed of the six Cas proteins (Cmr1-Cmr6) and a crRNA, captures and cleaves RNA complementary to the crRNA guide sequence. Here, a Cmr1-deficient functional Cmr (CmrΔ1) complex composed of Pyrococcus furiosus Cmr2-Cmr3, Archaeoglobus fulgidus Cmr4-Cmr5-Cmr6 and the 39-mer P. furiosus 7.01-crRNA was prepared. The CmrΔ1 complex was cocrystallized with single-stranded DNA (ssDNA) complementary to the crRNA guide by the vapour-diffusion method. The crystals diffracted to 2.1 Å resolution using synchrotron radiation at the Photon Factory. The crystals belonged to the triclinic space group P1, with unit-cell parameters a = 75.5, b = 76.2, c = 139.2 Å, α = 90.3, β = 104.8, γ = 118.6°. The asymmetric unit of the crystals is expected to contain one CmrΔ1-ssDNA complex, with a Matthews coefficient of 2.03 Å(3) Da(-1) and a solvent content of 39.5%.

  4. Development of a calibration protocol for quantitative imaging for molecular radiotherapy dosimetry

    International Nuclear Information System (INIS)

    Wevrett, J.; Fenwick, A.; Scuffham, J.; Nisbet, A.

    2017-01-01

    Within the field of molecular radiotherapy, there is a significant need for standardisation in dosimetry, in both quantitative imaging and dosimetry calculations. Currently, there are a wide range of techniques used by different clinical centres and as a result there is no means to compare patient doses between centres. To help address this need, a 3 year project was funded by the European Metrology Research Programme, and a number of clinical centres were involved in the project. One of the required outcomes of the project was to develop a calibration protocol for three dimensional quantitative imaging of volumes of interest. Two radionuclides were selected as being of particular interest: iodine-131 ( 131 I, used to treat thyroid disorders) and lutetium-177 ( 177 Lu, used to treat neuroendocrine tumours). A small volume of activity within a scatter medium (water), representing a lesion within a patient body, was chosen as the calibration method. To ensure ease of use in clinical centres, an “off-the-shelf” solution was proposed – to avoid the need for in-house manufacturing. The BIODEX elliptical Jaszczak phantom and 16 ml fillable sphere were selected. The protocol was developed for use on SPECT/CT gamma cameras only, where the CT dataset would be used to correct the imaging data for attenuation of the emitted photons within the phantom. The protocol corrects for scatter of emitted photons using the triple energy window correction technique utilised by most clinical systems. A number of clinical systems were tested in the development of this protocol, covering the major manufacturers of gamma camera generally used in Europe. Initial imaging was performed with 131 I and 177 Lu at a number of clinical centres, but due to time constraints in the project, some acquisitions were performed with 177 Lu only. The protocol is relatively simplistic, and does not account for the effects of dead-time in high activity patients, the presence of background activity

  5. Automatic spectral imaging protocol selection and iterative reconstruction in abdominal CT with reduced contrast agent dose: initial experience.

    Science.gov (United States)

    Lv, Peijie; Liu, Jie; Chai, Yaru; Yan, Xiaopeng; Gao, Jianbo; Dong, Junqiang

    2017-01-01

    To evaluate the feasibility, image quality, and radiation dose of automatic spectral imaging protocol selection (ASIS) and adaptive statistical iterative reconstruction (ASIR) with reduced contrast agent dose in abdominal multiphase CT. One hundred and sixty patients were randomly divided into two scan protocols (n = 80 each; protocol A, 120 kVp/450 mgI/kg, filtered back projection algorithm (FBP); protocol B, spectral CT imaging with ASIS and 40 to 70 keV monochromatic images generated per 300 mgI/kg, ASIR algorithm. Quantitative parameters (image noise and contrast-to-noise ratios [CNRs]) and qualitative visual parameters (image noise, small structures, organ enhancement, and overall image quality) were compared. Monochromatic images at 50 keV and 60 keV provided similar or lower image noise, but higher contrast and overall image quality as compared with 120-kVp images. Despite the higher image noise, 40-keV images showed similar overall image quality compared to 120-kVp images. Radiation dose did not differ between the two protocols, while contrast agent dose in protocol B was reduced by 33 %. Application of ASIR and ASIS to monochromatic imaging from 40 to 60 keV allowed contrast agent dose reduction with adequate image quality and without increasing radiation dose compared to 120 kVp with FBP. • Automatic spectral imaging protocol selection provides appropriate scan protocols. • Abdominal CT is feasible using spectral imaging and 300 mgI/kg contrast agent. • 50-keV monochromatic images with 50 % ASIR provide optimal image quality.

  6. Development of a quality assurance protocol for peripheral subtraction imaging applications

    International Nuclear Information System (INIS)

    Walsh, C.; Murphy, D.; O'Hare, N.

    2002-01-01

    Peripheral subtraction scanning is used to trace the blood vessels of upper and lower extremities. In some modern C-arm fluoroscopy systems this function is performed automatically. In this mode the system is programmed to advance and stop in a series of steps taking a mask image at each point. The system then repeats each step after the contrast agent has been injected, and produces a DSA image at each point. Current radiographic quality assurance protocols do not address this feature. This note reviews methods of measuring system vibration while images are being acquired in automated peripheral stepping. The effect on image quality pre- and post-image processing is assessed. Results show that peripheral stepping DSA does not provide the same degree of image quality as static DSA. In examining static test objects, the major cause of the reduction in image quality is misregistration due to vibration of the image intensifier during imaging. (author)

  7. Myocardial deformation assessed by longitudinal strain. Chamber specific normative data for CMR-feature tracking from the German competence network for congenital heart defects

    International Nuclear Information System (INIS)

    Shang, Quanliang; Patel, Shivani; Danford, David A.; Kutty, Shelby; Steinmetz, Michael; Schuster, Andreas; Beerbaum, Philipp; Sarikouch, Samir

    2018-01-01

    Left ventricular two-dimensional global longitudinal strain (LS) is superior to ejection fraction (EF) as predictor of outcome. We provide reference data for atrial and ventricular global LS during childhood and adolescence by CMR feature tracking (FT). We prospectively enrolled 115 healthy subjects (56 male, mean age 12.4 ± 4.1 years) at a single institution. CMR consisted of standard two-dimensional steady-state free-precession acquisitions. CMR-FT was performed on ventricular horizontal long-axis images for derivation of right and left atrial (RA, LA) and right and left ventricular (RV, LV) peak global LS. End-diastolic volumes (EDVs) and EF were measured. Correlations were explored for LS with age, EDV and EF of each chamber. Mean±SD of LS (%) for RA, RV, LA and LV were 26.56±10.2, -17.96±5.4, 26.45±10.6 and -17.47±5, respectively. There was a positive correlation of LS in LA, LV, RA and RV with corresponding EF (all P<0.05); correlations with age were weak. Gender-wise differences were not significant for atrial and ventricular LS, strain rate and displacement. Inter- and intra-observer comparisons showed moderate agreements. Chamber-specific nomograms for paediatric atrial and ventricular LS are provided to serve as clinical reference, and to facilitate CMR-based deformation research. (orig.)

  8. Myocardial deformation assessed by longitudinal strain. Chamber specific normative data for CMR-feature tracking from the German competence network for congenital heart defects

    Energy Technology Data Exchange (ETDEWEB)

    Shang, Quanliang [University of Nebraska College of Medicine, Children' s Hospital and Medical Center, Division of Pediatric Cardiology, Omaha, NE (United States); Central South University, Department of Radiology, Second Xiangya Hospital, Changsha, Hunan Province (China); Patel, Shivani; Danford, David A.; Kutty, Shelby [University of Nebraska College of Medicine, Children' s Hospital and Medical Center, Division of Pediatric Cardiology, Omaha, NE (United States); Steinmetz, Michael [Georg-August-University and German Centre for Cardiovascular Research (DZHK, Partner Site), Department of Paediatric Cardiology, Goettingen (Germany); Schuster, Andreas [Georg-August-University and German Centre for Cardiovascular Research (DZHK, Partner Site), Department of Cardiology and Pulmonology, Goettingen (Germany); Beerbaum, Philipp; Sarikouch, Samir [Hanover Medical School, Hanover (Germany)

    2018-03-15

    Left ventricular two-dimensional global longitudinal strain (LS) is superior to ejection fraction (EF) as predictor of outcome. We provide reference data for atrial and ventricular global LS during childhood and adolescence by CMR feature tracking (FT). We prospectively enrolled 115 healthy subjects (56 male, mean age 12.4 ± 4.1 years) at a single institution. CMR consisted of standard two-dimensional steady-state free-precession acquisitions. CMR-FT was performed on ventricular horizontal long-axis images for derivation of right and left atrial (RA, LA) and right and left ventricular (RV, LV) peak global LS. End-diastolic volumes (EDVs) and EF were measured. Correlations were explored for LS with age, EDV and EF of each chamber. Mean±SD of LS (%) for RA, RV, LA and LV were 26.56±10.2, -17.96±5.4, 26.45±10.6 and -17.47±5, respectively. There was a positive correlation of LS in LA, LV, RA and RV with corresponding EF (all P<0.05); correlations with age were weak. Gender-wise differences were not significant for atrial and ventricular LS, strain rate and displacement. Inter- and intra-observer comparisons showed moderate agreements. Chamber-specific nomograms for paediatric atrial and ventricular LS are provided to serve as clinical reference, and to facilitate CMR-based deformation research. (orig.)

  9. Evaluating the systemic right ventricle by CMR: the importance of consistent and reproducible delineation of the cavity

    Directory of Open Access Journals (Sweden)

    van Dijk Arie PJ

    2008-08-01

    Full Text Available Abstract Background The method used to delineate the boundary of the right ventricle (RV, relative to the trabeculations and papillary muscles in cardiovascular magnetic resonance (CMR ventricular volume analysis, may matter more when these structures are hypertrophied than in individuals with normal cardiovascular anatomy. This study aimed to compare two methods of cavity delineation in patients with systemic RV. Methods Twenty-nine patients (mean age 34.7 ± 12.4 years with a systemic RV (12 with congenitally corrected transposition of the great arteries (ccTGA and 17 with atrially switched (TGA underwent CMR. We compared measurements of systemic RV volumes and function using two analysis protocols. The RV trabeculations and papillary muscles were either included in the calculated blood volume, the boundary drawn immediately within the apparently compacted myocardial layer, or they were manually outlined and excluded. RV stroke volume (SV calculated using each method was compared with corresponding left ventricular (LV SV. Additionally, we compared the differences in analysis time, and in intra- and inter-observer variability between the two methods. Paired samples t-test was used to test for differences in volumes, function and analysis time between the two methods. Differences in intra- and inter-observer reproducibility were tested using an extension of the Bland-Altman method. Results The inclusion of trabeculations and papillary muscles in the ventricular volume resulted in higher values for systemic RV end diastolic volume (mean difference 28.7 ± 10.6 ml, p Conclusion The choice of method for systemic RV cavity delineation significantly affected volume measurements, given the CMR acquisition and analysis systems used. We recommend delineation outside the trabeculations for routine clinical measurements of systemic RV volumes as this approach took less time and gave more reproducible measurements.

  10. Compositional breast imaging using a dual-energy mammography protocol

    International Nuclear Information System (INIS)

    Laidevant, Aurelie D.; Malkov, Serghei; Flowers, Chris I.; Kerlikowske, Karla; Shepherd, John A.

    2010-01-01

    Purpose: Mammography has a low sensitivity in dense breasts due to low contrast between malignant and normal tissue confounded by the predominant water density of the breast. Water is found in both adipose and fibroglandular tissue and constitutes most of the mass of a breast. However, significant protein mass is mainly found in the fibroglandular tissue where most cancers originate. If the protein compartment in a mammogram could be imaged without the influence of water, the sensitivity and specificity of the mammogram may be improved. This article describes a novel approach to dual-energy mammography, full-field digital compositional mammography (FFDCM), which can independently image the three compositional components of breast tissue: water, lipid, and protein. Methods: Dual-energy attenuation and breast shape measures are used together to solve for the three compositional thicknesses. Dual-energy measurements were performed on breast-mimicking phantoms using a full-field digital mammography unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the compositional compartments. They were made of two main stacks of thicknesses around 2 and 4 cm. Twenty-six thickness and composition combinations were used to derive the compositional calibration using a least-squares fitting approach. Results: Very high accuracy was achieved with a simple cubic fitting function with root mean square errors of 0.023, 0.011, and 0.012 cm for the water, lipid, and protein thicknesses, respectively. The repeatability (percent coefficient of variation) of these measures was tested using sequential images and was found to be 0.5%, 0.5%, and 3.3% for water, lipid, and protein, respectively. However, swapping the location of the two stacks of the phantom on the imaging plate introduced further errors showing the need for more complete system uniformity corrections. Finally, a preliminary breast image is presented of each of the compositional

  11. Normalization of cortical thickness measurements across different T1 magnetic resonance imaging protocols by novel W-Score standardization.

    Science.gov (United States)

    Chung, Jinyong; Yoo, Kwangsun; Lee, Peter; Kim, Chan Mi; Roh, Jee Hoon; Park, Ji Eun; Kim, Sang Joon; Seo, Sang Won; Shin, Jeong-Hyeon; Seong, Joon-Kyung; Jeong, Yong

    2017-10-01

    The use of different 3D T1-weighted magnetic resonance (T1 MR) imaging protocols induces image incompatibility across multicenter studies, negating the many advantages of multicenter studies. A few methods have been developed to address this problem, but significant image incompatibility still remains. Thus, we developed a novel and convenient method to improve image compatibility. W-score standardization creates quality reference values by using a healthy group to obtain normalized disease values. We developed a protocol-specific w-score standardization to control the protocol effect, which is applied to each protocol separately. We used three data sets. In dataset 1, brain T1 MR images of normal controls (NC) and patients with Alzheimer's disease (AD) from two centers, acquired with different T1 MR protocols, were used (Protocol 1 and 2, n = 45/group). In dataset 2, data from six subjects, who underwent MRI with two different protocols (Protocol 1 and 2), were used with different repetition times, echo times, and slice thicknesses. In dataset 3, T1 MR images from a large number of healthy normal controls (Protocol 1: n = 148, Protocol 2: n = 343) were collected for w-score standardization. The protocol effect and disease effect on subjects' cortical thickness were analyzed before and after the application of protocol-specific w-score standardization. As expected, different protocols resulted in differing cortical thickness measurements in both NC and AD subjects. Different measurements were obtained for the same subject when imaged with different protocols. Multivariate pattern difference between measurements was observed between the protocols. Classification accuracy between two protocols was nearly 90%. After applying protocol-specific w-score standardization, the differences between the protocols substantially decreased. Most importantly, protocol-specific w-score standardization reduced both univariate and multivariate differences in the images while

  12. Optimized workflow and imaging protocols for whole-body oncologic PET/MRI.

    Science.gov (United States)

    Ishii, Shirou; Hara, Takamitsu; Nanbu, Takeyuki; Suenaga, Hiroki; Sugawara, Shigeyasu; Kuroiwa, Daichi; Sekino, Hirofumi; Miyajima, Masayuki; Kubo, Hitoshi; Oriuchi, Noboru; Ito, Hiroshi

    2016-11-01

    Although PET/MRI has the advantages of a simultaneous acquisition of PET and MRI, high soft-tissue contrast of the MRI images, and reduction of radiation exposure, its low profitability and long acquisition time are significant problems in clinical settings. Thus, MRI protocols that meet oncological purposes need to be used in order to reduce examination time while securing detectability. Currently, half-Fourier acquisition single-shot turbo spin echo and 3D-T1 volumetric interpolated breath-hold examination may be the most commonly used sequences for whole-body imaging due to their shorter acquisition time and higher diagnostic accuracy. Although there have been several reports that adding diffusion weighted image (DWI) to PET/MRI protocol has had no effect on tumor detection to date, in cases of liver, kidney, bladder, and prostate cancer, the use of DWI may be beneficial in detecting lesions. Another possible option is to scan each region with different MRI sequences instead of scanning the whole body using one sequence continuously. We herein report a workflow and imaging protocols for whole-body oncologic PET/MRI using an integrated system in the clinical routine, designed for the detection, for example by cancer screening, of metastatic lesions, in order to help future users optimize their workflow and imaging protocols.

  13. Magnetic resonance imaging protocols for examination of the neurocranium at 3 T.

    Science.gov (United States)

    Schwindt, W; Kugel, H; Bachmann, R; Kloska, S; Allkemper, T; Maintz, D; Pfleiderer, B; Tombach, B; Heindel, W

    2003-09-01

    The increasing availability of high-field (3 T) MR scanners requires adapting and optimizing clinical imaging protocols to exploit the theoretically higher signal-to-noise ratio (SNR) of the higher field strength. Our aim was to establish reliable and stable protocols meeting the clinical demands for imaging the neurocranium at 3 T. Two hundred patients with a broad range of indications received an examination of the neurocranium with an appropriate assortment of imaging techniques at 3 T. Several imaging parameters were optimized. Keeping scan times comparable to those at 1.5 T we increased spatial resolution. Contrast-enhanced and non-enhanced T1-weighted imaging was best applying gradient-echo and inversion recovery (rather than spin-echo) techniques, respectively. For fluid-attenuated inversion recovery (FLAIR) imaging a TE of 120 ms yielded optimum contrast-to-noise ratio (CNR). High-resolution isotropic 3D data sets were acquired within reasonable scan times. Some artifacts were pronounced, but generally imaging profited from the higher SNR. We present a set of optimized examination protocols for neuroimaging at 3 T, which proved to be reliable in a clinical routine setting.

  14. Magnetic resonance imaging protocols for examination of the neurocranium at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Schwindt, W.; Kugel, H.; Bachmann, R.; Kloska, S.; Allkemper, T.; Maintz, D.; Pfleiderer, B.; Tombach, B.; Heindel, W. [Institut fuer Klinische Radiologie, Universitaetsklinikum Muenster, Albert-Schweitzer-Strasse 33, 48129, Muenster (Germany)

    2003-09-01

    The increasing availability of high-field (3 T) MR scanners requires adapting and optimizing clinical imaging protocols to exploit the theoretically higher signal-to-noise ratio (SNR) of the higher field strength. Our aim was to establish reliable and stable protocols meeting the clinical demands for imaging the neurocranium at 3 T. Two hundred patients with a broad range of indications received an examination of the neurocranium with an appropriate assortment of imaging techniques at 3 T. Several imaging parameters were optimized. Keeping scan times comparable to those at 1.5 T we increased spatial resolution. Contrast-enhanced and non-enhanced T1-weighted imaging was best applying gradient-echo and inversion recovery (rather than spin-echo) techniques, respectively. For fluid-attenuated inversion recovery (FLAIR) imaging a TE of 120 ms yielded optimum contrast-to-noise ratio (CNR). High-resolution isotropic 3D data sets were acquired within reasonable scan times. Some artifacts were pronounced, but generally imaging profited from the higher SNR. We present a set of optimized examination protocols for neuroimaging at 3 T, which proved to be reliable in a clinical routine setting. (orig.)

  15. Magnetic resonance imaging protocols for examination of the neurocranium at 3 T

    International Nuclear Information System (INIS)

    Schwindt, W.; Kugel, H.; Bachmann, R.; Kloska, S.; Allkemper, T.; Maintz, D.; Pfleiderer, B.; Tombach, B.; Heindel, W.

    2003-01-01

    The increasing availability of high-field (3 T) MR scanners requires adapting and optimizing clinical imaging protocols to exploit the theoretically higher signal-to-noise ratio (SNR) of the higher field strength. Our aim was to establish reliable and stable protocols meeting the clinical demands for imaging the neurocranium at 3 T. Two hundred patients with a broad range of indications received an examination of the neurocranium with an appropriate assortment of imaging techniques at 3 T. Several imaging parameters were optimized. Keeping scan times comparable to those at 1.5 T we increased spatial resolution. Contrast-enhanced and non-enhanced T1-weighted imaging was best applying gradient-echo and inversion recovery (rather than spin-echo) techniques, respectively. For fluid-attenuated inversion recovery (FLAIR) imaging a TE of 120 ms yielded optimum contrast-to-noise ratio (CNR). High-resolution isotropic 3D data sets were acquired within reasonable scan times. Some artifacts were pronounced, but generally imaging profited from the higher SNR. We present a set of optimized examination protocols for neuroimaging at 3 T, which proved to be reliable in a clinical routine setting. (orig.)

  16. The influence of referral protocols on the utilization of magnetic resonance imaging: evidence from Manitoba

    Energy Technology Data Exchange (ETDEWEB)

    Mustard, C.A.; McClarty, B.M.; MacEwan, D.W. [Manitoba Univ., Winnipeg, MB (Canada)

    1994-04-01

    The influence of referral protocols on the utilization of magnetic resonance imaging (MRI) services was studied. Three neuroradiologists and one radiologist reviewed the indications for MRI for 198 referrals to a facility in Winnipeg, selected at random from patients seen in 1991 for suspected disorders of the brain or the spine. Out-of-province referrals had not been subject to referral protocols, whereas those from within Manitoba had been subject to such protocols. At least three of the four radiologists agreed on whether an examination was appropriate in 88.4 % of the cases. Out-of-province referrals were significantly more likely to be considered inappropriate for MRI (24 %) than referrals from within Manitoba (10 %). It was estimated that the combined effect of instituting protocols and reviewing each referral before the examination could result in a 16 % to 31 % reduction in the demand for MRI services without compromising diagnostic information. 18 refs., 3 tabs.

  17. Dental-CT: image quality and absorbed radiation dose of different scan protocols

    International Nuclear Information System (INIS)

    Schorn, C.; Alamo, L.; Funke, M.; Grabbe, E.; Visser, H.; Hermann, K.P.

    1999-01-01

    Purpose: To develop a scan protocol for dental-CT which guarantees good image quality at the lowest possible radiation dose. Methods: In an experimental investigation Dental-CT (HSA, GE, Milwaukee, USA) of the mandible of two human skeletons positioned in a water tank were performed in order to define the most advantageous scan protocol. Tube currents ranged from 40 to 200 mA and the scan technique was modified (axial mode or helical mode with pitches of 1 to 3 and corresponding increments of 0.4 to 1.0 mm). 39 patients underwent a dental-CT with decreased current (80 mA) in the helical scan mode (pitch 2, slice thickness 1 mm). Dose measurements were performed for two different scan protocols (A: axial, 130 mAs, B: helical, 80 mA, pitch 2). Results: The preliminary investigations of image quality showed only a minor effect of the applied current. For the helical scan mode, pitches of more than 2 impaired image quality. A low increment had no advantages. There were no disadvantages in clinical practice using protocol B with decreased tube current. Absorbed radiation dose of dental CT performed with protocol B was decreased to one third in comparison to protocol A. Conclusions: A scan protocol with a low tube current (e.g., 80 mA, for a rotation time of 1 s) and a helical scan mode (e.g., for a slice thickness of 1 mm with a pitch of 2 and an increment of 1 mm) is recommended for performing dental-CT. (orig.) [de

  18. Imaging algorithms and CT protocols in trauma patients: survey of Swiss emergency centers

    International Nuclear Information System (INIS)

    Hinzpeter, R.; Alkadhi, Hatem; Boehm, T.; Boll, D.; Constantin, C.; Del Grande, F.; Fretz, V.; Leschka, S.; Ohletz, T.; Broennimann, M.; Schmidt, S.; Treumann, T.; Poletti, P.A.

    2017-01-01

    To identify imaging algorithms and indications, CT protocols, and radiation doses in polytrauma patients in Swiss trauma centres. An online survey with multiple choice questions and free-text responses was sent to authorized level-I trauma centres in Switzerland. All centres responded and indicated that they have internal standardized imaging algorithms for polytrauma patients. Nine of 12 centres (75 %) perform whole-body CT (WBCT) after focused assessment with sonography for trauma (FAST) and conventional radiography; 3/12 (25 %) use WBCT for initial imaging. Indications for WBCT were similar across centres being based on trauma mechanisms, vital signs, and presence of multiple injuries. Seven of 12 centres (58 %) perform an arterial and venous phase of the abdomen in split-bolus technique. Six of 12 centres (50 %) use multiphase protocols of the head (n = 3) and abdomen (n = 4), whereas 6/12 (50 %) use single-phase protocols for WBCT. Arm position was on the patient's body during scanning (3/12, 25 %), alongside the body (2/12, 17 %), above the head (2/12, 17 %), or was changed during scanning (5/12, 42 %). Radiation doses showed large variations across centres ranging from 1268-3988 mGy*cm (DLP) per WBCT. Imaging algorithms in polytrauma patients are standardized within, but vary across Swiss trauma centres, similar to the individual WBCT protocols, resulting in large variations in associated radiation doses. (orig.)

  19. Imaging algorithms and CT protocols in trauma patients: survey of Swiss emergency centers

    Energy Technology Data Exchange (ETDEWEB)

    Hinzpeter, R.; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Boehm, T. [Kantonsspital Graubuenden, Department of Radiology, Chur (Switzerland); Boll, D. [University Hospital Basel, Department of Radiology and Nuclear Medicine, Basel (Switzerland); Constantin, C. [Spital Wallis, Department of Radiology, Visp (Switzerland); Del Grande, F. [Ospedale Regionale di Lugano, Department of Radiology, Lugano (Switzerland); Fretz, V. [Kantonsspital Winterthur, Institute of Radiology and Nuclear Medicine, Winterthur (Switzerland); Leschka, S. [Kantonsspital St Gallen, Division of Radiology and Nuclear Medicine, Gallen (Switzerland); Ohletz, T. [Kantonsspital Aarau, Department of Radiology, Aarau (Switzerland); Broennimann, M. [University Hospital Bern, Department of Diagnostic, Interventional and Pediatric Radiology, Bern (Switzerland); Schmidt, S. [Lausanne University Hospital, Department of Diagnostic and Interventional Radiology, Lausanne (Switzerland); Treumann, T. [Luzerner Kantonsspital, Institute of Radiology, Luzern 16 (Switzerland); Poletti, P.A. [Geneva University Hospital, Department of Radiology, Geneve (Switzerland)

    2017-05-15

    To identify imaging algorithms and indications, CT protocols, and radiation doses in polytrauma patients in Swiss trauma centres. An online survey with multiple choice questions and free-text responses was sent to authorized level-I trauma centres in Switzerland. All centres responded and indicated that they have internal standardized imaging algorithms for polytrauma patients. Nine of 12 centres (75 %) perform whole-body CT (WBCT) after focused assessment with sonography for trauma (FAST) and conventional radiography; 3/12 (25 %) use WBCT for initial imaging. Indications for WBCT were similar across centres being based on trauma mechanisms, vital signs, and presence of multiple injuries. Seven of 12 centres (58 %) perform an arterial and venous phase of the abdomen in split-bolus technique. Six of 12 centres (50 %) use multiphase protocols of the head (n = 3) and abdomen (n = 4), whereas 6/12 (50 %) use single-phase protocols for WBCT. Arm position was on the patient's body during scanning (3/12, 25 %), alongside the body (2/12, 17 %), above the head (2/12, 17 %), or was changed during scanning (5/12, 42 %). Radiation doses showed large variations across centres ranging from 1268-3988 mGy*cm (DLP) per WBCT. Imaging algorithms in polytrauma patients are standardized within, but vary across Swiss trauma centres, similar to the individual WBCT protocols, resulting in large variations in associated radiation doses. (orig.)

  20. Structure of the Cmr2 Subunit of the CRISPR-Cas RNA Silencing Complex

    Energy Technology Data Exchange (ETDEWEB)

    Cocozaki, Alexis I.; Ramia, Nancy F.; Shao, Yaming; Hale, Caryn R.; Terns, Rebecca M.; Terns, Michael P.; Li, Hong (FSU); (Georgia)

    2012-08-10

    Cmr2 is the largest and an essential subunit of a CRISPR RNA-Cas protein complex (the Cmr complex) that cleaves foreign RNA to protect prokaryotes from invading genetic elements. Cmr2 is thought to be the catalytic subunit of the effector complex because of its N-terminal HD nuclease domain. Here, however, we report that the HD domain of Cmr2 is not required for cleavage by the complex in vitro. The 2.3 {angstrom} crystal structure of Pyrococcus furiosus Cmr2 (lacking the HD domain) reveals two adenylyl cyclase-like and two {alpha}-helical domains. The adenylyl cyclase-like domains are arranged as in homodimeric adenylyl cyclases and bind ADP and divalent metals. However, mutagenesis studies show that the metal- and ADP-coordinating residues of Cmr2 are also not critical for cleavage by the complex. Our findings suggest that another component provides the catalytic function and that the essential role by Cmr2 does not require the identified ADP- or metal-binding or HD domains in vitro.

  1. In vivo cellular imaging using fluorescent proteins - Methods and Protocols

    Directory of Open Access Journals (Sweden)

    M. Monti

    2012-12-01

    Full Text Available The discovery and genetic engineering of fluorescent proteins has revolutionized cell biology. What was previously invisible to the cell often can be made visible with the use of fluorescent proteins. With this words, Robert M. Hoffman introduces In vivo Cellular Imaging Using Fluorescent proteins, the eighteen chapters book dedicated to the description of how fluorescence proteins have changed the way to analyze cellular processes in vivo. Modern researches aim to study new and less invasive methods able to follow the behavior of different cell types in different biological contexts: for example, how cancer cells migrate or how they respond to different therapies. Also, in vivo systems can help researchers to better understand animal embryonic development so as how fluorescence proteins may be used to monitor different processes in living organisms at the molecular and cellular level.

  2. Varied exposure to carcinogenic, mutagenic, and reprotoxic (CMR) chemicals in occupational settings in France

    Energy Technology Data Exchange (ETDEWEB)

    Havet, Nathalie [Univ. Claude Bernard Lyon 1 (France). Lab. SAF; Penot, Alexis [Lyon Univ. (France). ENS Lyon, GATE-UMR 5824-CNRS; Morelle, Magali; Perrier, Lionel [Lyon Univ. (France). Direction de la Recherche Clinique et de l' Innovation; Charbotel, Barbara [Univ. Claude Bernard Lyon 1 (France). Centre Hospitalier Lyon Sud Service des Maladies Professionnelles; Fervers, Beatrice [Lyon Univ. (France). Dept. Cancer and Environment

    2017-02-15

    To explore varied exposure to carcinogenic, mutagenic, and reprotoxic chemicals (CMR) for French employees. Our study assessed data from the French national cross-sectional survey of occupational risks (SUMER) that was conducted in 2010 in a national representative sample of employees. We selected 28 CMR agents that were classified by the International Agency for Research on Cancer or European Union as being known or presumed to have CMR potential in humans. The association of individual and job characteristics with exposure prevalence, duration, and intensity of the CMR agents during a 1-week period was examined using multilevel logistic regression analysis. Overall, 10.4% of employees in 2010 were exposed to one or more CMR agents at their workplace, and 3.4% were subjected to multiple CMR exposures. Blue-collar workers, night-shift workers and workers with short-term employment contracts experienced higher exposure prevalence (p < 0.01) and intensity (p < 0.05). Bluecollar workers and shift workers experienced also longer exposure duration (p < 0.001). Conversely, managers, workers of large companies, and women were less exposed to CMR agents (p < 0.001). The presence of a Committee for Health, Safety, and Working Conditions, and intervention by Occupational Health and Safety officers were significantly associated with reduced exposure intensities (p < 0.001 and p < 0.05). Establishment of European CMR regulations and the existence of an applicable substitution principle reduced the exposure duration (p < 0.001) and intensity (p < 0.05). Our results point out disparities in CMR exposure and identify high-priority targets for prevention measures to help reducing social health discrepancies.

  3. Varied exposure to carcinogenic, mutagenic, and reprotoxic (CMR) chemicals in occupational settings in France

    International Nuclear Information System (INIS)

    Havet, Nathalie; Penot, Alexis; Morelle, Magali; Perrier, Lionel; Charbotel, Barbara; Fervers, Beatrice

    2017-01-01

    To explore varied exposure to carcinogenic, mutagenic, and reprotoxic chemicals (CMR) for French employees. Our study assessed data from the French national cross-sectional survey of occupational risks (SUMER) that was conducted in 2010 in a national representative sample of employees. We selected 28 CMR agents that were classified by the International Agency for Research on Cancer or European Union as being known or presumed to have CMR potential in humans. The association of individual and job characteristics with exposure prevalence, duration, and intensity of the CMR agents during a 1-week period was examined using multilevel logistic regression analysis. Overall, 10.4% of employees in 2010 were exposed to one or more CMR agents at their workplace, and 3.4% were subjected to multiple CMR exposures. Blue-collar workers, night-shift workers and workers with short-term employment contracts experienced higher exposure prevalence (p < 0.01) and intensity (p < 0.05). Bluecollar workers and shift workers experienced also longer exposure duration (p < 0.001). Conversely, managers, workers of large companies, and women were less exposed to CMR agents (p < 0.001). The presence of a Committee for Health, Safety, and Working Conditions, and intervention by Occupational Health and Safety officers were significantly associated with reduced exposure intensities (p < 0.001 and p < 0.05). Establishment of European CMR regulations and the existence of an applicable substitution principle reduced the exposure duration (p < 0.001) and intensity (p < 0.05). Our results point out disparities in CMR exposure and identify high-priority targets for prevention measures to help reducing social health discrepancies.

  4. Optimized protocols for cardiac magnetic resonance imaging in patients with thoracic metallic implants.

    Science.gov (United States)

    Olivieri, Laura J; Cross, Russell R; O'Brien, Kendall E; Ratnayaka, Kanishka; Hansen, Michael S

    2015-09-01

    Cardiac magnetic resonance (MR) imaging is a valuable tool in congenital heart disease; however patients frequently have metal devices in the chest from the treatment of their disease that complicate imaging. Methods are needed to improve imaging around metal implants near the heart. Basic sequence parameter manipulations have the potential to minimize artifact while limiting effects on image resolution and quality. Our objective was to design cine and static cardiac imaging sequences to minimize metal artifact while maintaining image quality. Using systematic variation of standard imaging parameters on a fluid-filled phantom containing commonly used metal cardiac devices, we developed optimized sequences for steady-state free precession (SSFP), gradient recalled echo (GRE) cine imaging, and turbo spin-echo (TSE) black-blood imaging. We imaged 17 consecutive patients undergoing routine cardiac MR with 25 metal implants of various origins using both standard and optimized imaging protocols for a given slice position. We rated images for quality and metal artifact size by measuring metal artifact in two orthogonal planes within the image. All metal artifacts were reduced with optimized imaging. The average metal artifact reduction for the optimized SSFP cine was 1.5+/-1.8 mm, and for the optimized GRE cine the reduction was 4.6+/-4.5 mm (P metal artifact reduction for the optimized TSE images was 1.6+/-1.7 mm (P metal artifact are easily created by modifying basic sequence parameters, and images are superior to standard imaging sequences in both quality and artifact size. Specifically, for optimized cine imaging a GRE sequence should be used with settings that favor short echo time, i.e. flow compensation off, weak asymmetrical echo and a relatively high receiver bandwidth. For static black-blood imaging, a TSE sequence should be used with fat saturation turned off and high receiver bandwidth.

  5. A standardised protocol for texture feature analysis of endoscopic images in gynaecological cancer

    Directory of Open Access Journals (Sweden)

    Pattichis Marios S

    2007-11-01

    Full Text Available Abstract Background In the development of tissue classification methods, classifiers rely on significant differences between texture features extracted from normal and abnormal regions. Yet, significant differences can arise due to variations in the image acquisition method. For endoscopic imaging of the endometrium, we propose a standardized image acquisition protocol to eliminate significant statistical differences due to variations in: (i the distance from the tissue (panoramic vs close up, (ii difference in viewing angles and (iii color correction. Methods We investigate texture feature variability for a variety of targets encountered in clinical endoscopy. All images were captured at clinically optimum illumination and focus using 720 × 576 pixels and 24 bits color for: (i a variety of testing targets from a color palette with a known color distribution, (ii different viewing angles, (iv two different distances from a calf endometrial and from a chicken cavity. Also, human images from the endometrium were captured and analysed. For texture feature analysis, three different sets were considered: (i Statistical Features (SF, (ii Spatial Gray Level Dependence Matrices (SGLDM, and (iii Gray Level Difference Statistics (GLDS. All images were gamma corrected and the extracted texture feature values were compared against the texture feature values extracted from the uncorrected images. Statistical tests were applied to compare images from different viewing conditions so as to determine any significant differences. Results For the proposed acquisition procedure, results indicate that there is no significant difference in texture features between the panoramic and close up views and between angles. For a calibrated target image, gamma correction provided an acquired image that was a significantly better approximation to the original target image. In turn, this implies that the texture features extracted from the corrected images provided for better

  6. MO-A-218-01: CT Protocol Review - Practical Tips for Imaging Physicists.

    Science.gov (United States)

    Pizzutiello, R

    2012-06-01

    In the 1980's and 90's, when every mammography department had a wet film processor and a sundial to keep the schedule, medical physicists performing mammography surveys were primarily focused on measuring machine performance and image quality. As our professional experience matured, medical physicists began to learn that they were uniquely qualified to help to recommend technique factors that would balance dose and image quality. Technique charts using different kVp, target-filter combinations and AEC modes gradually became common and patients benefitted from our input. With the revolutionary change in CT Scanner technology and utilization, medical physicists have begun to contribute their expertise to developing and improving CT protocols. This presentation will present practical challenges and offer some directions for the practicing medical physicist who desires to participate in this critical and emerging aspect of imaging physics practice: CT Protocol Review. © 2012 American Association of Physicists in Medicine.

  7. Evaluation of a new system for chest tomosynthesis: aspects of image quality of different protocols determined using an anthropomorphic phantom

    Science.gov (United States)

    Sundin, A; Aspelin, P; Båth, M; Nyrén, S

    2015-01-01

    Objective: To compare the image quality obtained with the different protocols in a new chest digital tomosynthesis (DTS) system. Methods: A chest phantom was imaged with chest X-ray equipment with DTS. 10 protocols were used, and for each protocol, nine acquisitions were performed. Four observers visually rated the quality of the reconstructed section images according to pre-defined quality criteria in four different classes. The data were analysed with visual grading characteristics (VGC) analysis, using the vendor-recommended protocol [12-s acquisition time, source-to-image distance (SID) 180 cm] as reference, and the area under the VGC curve (AUCVGC) was determined for each protocol and class of criteria. Results: Protocols with a smaller swing angle resulted in a lower image quality for the classes of criteria “disturbance” and “homogeneity in nodule” but a higher image quality for the class “structure”. The class “demarcation” showed little dependency on the swing angle. All protocols but one (6.3 s, SID 130 cm) obtained an AUCVGC significantly <0.5 (indicating lower quality than reference) for at least one class of criteria. Conclusion: The study indicates that the DTS protocol with 6.3 s yields image quality similar to that obtained with the vendor-recommended protocol (12 s) but with the clinically important advantage for patients with respiratory impairment of a shorter acquisition time. Advances in knowledge: The study demonstrates that the image quality may be strongly affected by the choice of protocol and that the vendor-recommended protocol may not be optimal. PMID:26118300

  8. Reducing sedation for pediatric body MRI using accelerated and abbreviated imaging protocols

    International Nuclear Information System (INIS)

    Ahmad, Rizwan; Hu, Houchun Harry; Krishnamurthy, Ramkumar; Krishnamurthy, Rajesh

    2018-01-01

    Magnetic resonance imaging (MRI) is an established diagnostic imaging tool for investigating pediatric disease. MRI allows assessment of structure, function, and morphology in cardiovascular imaging, as well as tissue characterization in body imaging, without the use of ionizing radiation. For MRI in children, sedation and general anesthesia (GA) are often utilized to suppress patient motion, which can otherwise compromise image quality and diagnostic efficacy. However, evidence is emerging that use of sedation and GA in children might have long-term neurocognitive side effects, in addition to the short-term procedure-related risks. These concerns make risk-benefit assessment of sedation and GA more challenging. Therefore, reducing or eliminating the need for sedation and GA is an important goal of imaging innovation and research in pediatric MRI. In this review, the authors focus on technical and clinical approaches to reducing and eliminating the use of sedation in the pediatric population based on image acquisition acceleration and imaging protocols abbreviation. This paper covers important physiological and technical considerations for pediatric body MR imaging and discusses MRI techniques that offer the potential of recovering diagnostic-quality images from accelerated scans. In this review, the authors also introduce the concept of reporting elements for important indications for pediatric body MRI and use this as a basis for abbreviating the MR protocols. By employing appropriate accelerated and abbreviated approaches based on an understanding of the imaging needs and reporting elements for a given clinical indication, it is possible to reduce sedation and GA for pediatric chest, cardiovascular and abdominal MRI. (orig.)

  9. Reducing sedation for pediatric body MRI using accelerated and abbreviated imaging protocols

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Rizwan [The Ohio State University, Department of Biomedical Engineering, Columbus, OH (United States); Hu, Houchun Harry; Krishnamurthy, Ramkumar; Krishnamurthy, Rajesh [Nationwide Children' s Hospital, Department of Radiology, Columbus, OH (United States)

    2018-01-15

    Magnetic resonance imaging (MRI) is an established diagnostic imaging tool for investigating pediatric disease. MRI allows assessment of structure, function, and morphology in cardiovascular imaging, as well as tissue characterization in body imaging, without the use of ionizing radiation. For MRI in children, sedation and general anesthesia (GA) are often utilized to suppress patient motion, which can otherwise compromise image quality and diagnostic efficacy. However, evidence is emerging that use of sedation and GA in children might have long-term neurocognitive side effects, in addition to the short-term procedure-related risks. These concerns make risk-benefit assessment of sedation and GA more challenging. Therefore, reducing or eliminating the need for sedation and GA is an important goal of imaging innovation and research in pediatric MRI. In this review, the authors focus on technical and clinical approaches to reducing and eliminating the use of sedation in the pediatric population based on image acquisition acceleration and imaging protocols abbreviation. This paper covers important physiological and technical considerations for pediatric body MR imaging and discusses MRI techniques that offer the potential of recovering diagnostic-quality images from accelerated scans. In this review, the authors also introduce the concept of reporting elements for important indications for pediatric body MRI and use this as a basis for abbreviating the MR protocols. By employing appropriate accelerated and abbreviated approaches based on an understanding of the imaging needs and reporting elements for a given clinical indication, it is possible to reduce sedation and GA for pediatric chest, cardiovascular and abdominal MRI. (orig.)

  10. A service protocol for post-processing of medical images on the mobile device

    Science.gov (United States)

    He, Longjun; Ming, Xing; Xu, Lang; Liu, Qian

    2014-03-01

    With computing capability and display size growing, the mobile device has been used as a tool to help clinicians view patient information and medical images anywhere and anytime. It is uneasy and time-consuming for transferring medical images with large data size from picture archiving and communication system to mobile client, since the wireless network is unstable and limited by bandwidth. Besides, limited by computing capability, memory and power endurance, it is hard to provide a satisfactory quality of experience for radiologists to handle some complex post-processing of medical images on the mobile device, such as real-time direct interactive three-dimensional visualization. In this work, remote rendering technology is employed to implement the post-processing of medical images instead of local rendering, and a service protocol is developed to standardize the communication between the render server and mobile client. In order to make mobile devices with different platforms be able to access post-processing of medical images, the Extensible Markup Language is taken to describe this protocol, which contains four main parts: user authentication, medical image query/ retrieval, 2D post-processing (e.g. window leveling, pixel values obtained) and 3D post-processing (e.g. maximum intensity projection, multi-planar reconstruction, curved planar reformation and direct volume rendering). And then an instance is implemented to verify the protocol. This instance can support the mobile device access post-processing of medical image services on the render server via a client application or on the web page.

  11. Appearance of microvascular obstruction on high resolution first-pass perfusion, early and late gadolinium enhancement CMR in patients with acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Redwood Simon

    2009-08-01

    Full Text Available Abstract Background The presence and extent of microvascular obstruction (MO after acute myocardial infarction can be measured by first-pass gadolinium-enhanced perfusion cardiovascular magnetic resonance (CMR or after gadolinium injection with early or late enhancement (EGE/LGE imaging. The volume of MO measured by these three methods may differ because contrast agent diffusion into the MO reduces its apparent extent over time. Theoretically, first-pass perfusion CMR should be the most accurate method to measure MO, but this technique has been limited by lower spatial resolution than EGE and LGE as well as incomplete cardiac coverage. These limitations of perfusion CMR can be overcome using spatio-temporal undersampling methods. The purpose of this study was to compare the extent of MO by high resolution first-pass k-t SENSE accelerated perfusion, EGE and LGE. Methods 34 patients with acute ST elevation myocardial infarction, treated successfully with primary percutaneous coronary intervention (PPCI, underwent CMR within 72 hours of admission. k-t SENSE accelerated first-pass perfusion MR (7 fold acceleration, spatial resolution 1.5 mm × 1.5 mm × 10 mm, 8 slices acquired over 2 RR intervals, 0.1 mmol/kg Gd-DTPA, EGE (1–4 minutes after injection with a fixed TI of 440 ms and LGE images (10–12 minutes after injection, TI determined by a Look-Locker scout were acquired. MO volume was determined for each technique by manual planimetry and summation of discs methodology. Results k-t SENSE first-pass perfusion detected more cases of MO than EGE and LGE (22 vs. 20 vs. 14, respectively. The extent of MO imaged by first-pass perfusion (median mass 4.7 g, IQR 6.7 was greater than by EGE (median mass 2.3 g, IQR 7.1, p = 0.002 and LGE (median mass 0.2 g, IQR 2.4, p = 0.0003. The correlation coefficient between MO mass measured by first-pass perfusion and EGE was 0.91 (p Conclusion The extent of MO following acute myocardial infarction appears larger on

  12. Three-pass protocol scheme for bitmap image security by using vernam cipher algorithm

    Science.gov (United States)

    Rachmawati, D.; Budiman, M. A.; Aulya, L.

    2018-02-01

    Confidentiality, integrity, and efficiency are the crucial aspects of data security. Among the other digital data, image data is too prone to abuse of operation like duplication, modification, etc. There are some data security techniques, one of them is cryptography. The security of Vernam Cipher cryptography algorithm is very dependent on the key exchange process. If the key is leaked, security of this algorithm will collapse. Therefore, a method that minimizes key leakage during the exchange of messages is required. The method which is used, is known as Three-Pass Protocol. This protocol enables message delivery process without the key exchange. Therefore, the sending messages process can reach the receiver safely without fear of key leakage. The system is built by using Java programming language. The materials which are used for system testing are image in size 200×200 pixel, 300×300 pixel, 500×500 pixel, 800×800 pixel and 1000×1000 pixel. The result of experiments showed that Vernam Cipher algorithm in Three-Pass Protocol scheme could restore the original image.

  13. Optimized protocols for cardiac magnetic resonance imaging in patients with thoracic metallic implants

    Energy Technology Data Exchange (ETDEWEB)

    Olivieri, Laura J.; Ratnayaka, Kanishka [Children' s National Health System, Division of Cardiology, Washington, DC (United States); National Institutes of Health, National Heart, Lung and Blood Institute, Bethesda, MD (United States); Cross, Russell R.; O' Brien, Kendall E. [Children' s National Health System, Division of Cardiology, Washington, DC (United States); Hansen, Michael S. [National Institutes of Health, National Heart, Lung and Blood Institute, Bethesda, MD (United States)

    2015-09-15

    Cardiac magnetic resonance (MR) imaging is a valuable tool in congenital heart disease; however patients frequently have metal devices in the chest from the treatment of their disease that complicate imaging. Methods are needed to improve imaging around metal implants near the heart. Basic sequence parameter manipulations have the potential to minimize artifact while limiting effects on image resolution and quality. Our objective was to design cine and static cardiac imaging sequences to minimize metal artifact while maintaining image quality. Using systematic variation of standard imaging parameters on a fluid-filled phantom containing commonly used metal cardiac devices, we developed optimized sequences for steady-state free precession (SSFP), gradient recalled echo (GRE) cine imaging, and turbo spin-echo (TSE) black-blood imaging. We imaged 17 consecutive patients undergoing routine cardiac MR with 25 metal implants of various origins using both standard and optimized imaging protocols for a given slice position. We rated images for quality and metal artifact size by measuring metal artifact in two orthogonal planes within the image. All metal artifacts were reduced with optimized imaging. The average metal artifact reduction for the optimized SSFP cine was 1.5+/-1.8 mm, and for the optimized GRE cine the reduction was 4.6+/-4.5 mm (P < 0.05). Quality ratings favored the optimized GRE cine. Similarly, the average metal artifact reduction for the optimized TSE images was 1.6+/-1.7 mm (P < 0.05), and quality ratings favored the optimized TSE imaging. Imaging sequences tailored to minimize metal artifact are easily created by modifying basic sequence parameters, and images are superior to standard imaging sequences in both quality and artifact size. Specifically, for optimized cine imaging a GRE sequence should be used with settings that favor short echo time, i.e. flow compensation off, weak asymmetrical echo and a relatively high receiver bandwidth. For static

  14. Implementing Protocols to Improve Patient Safety in the Medical Imaging Department.

    Science.gov (United States)

    Carrizales, Gwen; Clark, Kevin R

    2015-01-01

    Patient safety is a focal point in healthcare because of recent changes issued by CMS. Hospital reimbursement rates have fallen, and these reimbursement rates are governed by CMS mandates regarding patient safety procedures. Reimbursement changes are reflected in the National Patient Safety Goals (NPSGs) administered annually by The Joint Commission. Medical imaging departments have multiple areas of patient safety concerns including effective handoff communication, proper patient identification, and safe medication/contrast administration. This literature review examines those areas of patient safety within the medical imaging department and reveals the need for continued protocol and policy changes to keep patients safe.

  15. 3D T2-weighted imaging to shorten multiparametric prostate MRI protocols.

    Science.gov (United States)

    Polanec, Stephan H; Lazar, Mathias; Wengert, Georg J; Bickel, Hubert; Spick, Claudio; Susani, Martin; Shariat, Shahrokh; Clauser, Paola; Baltzer, Pascal A T

    2018-04-01

    To determine whether 3D acquisitions provide equivalent image quality, lesion delineation quality and PI-RADS v2 performance compared to 2D acquisitions in T2-weighted imaging of the prostate at 3 T. This IRB-approved, prospective study included 150 consecutive patients (mean age 63.7 years, 35-84 years; mean PSA 7.2 ng/ml, 0.4-31.1 ng/ml). Two uroradiologists (R1, R2) independently rated image quality and lesion delineation quality using a five-point ordinal scale and assigned a PI-RADS score for 2D and 3D T2-weighted image data sets. Data were compared using visual grading characteristics (VGC) and receiver operating characteristics (ROC)/area under the curve (AUC) analysis. Image quality was similarly good to excellent for 2D T2w (mean score R1, 4.3 ± 0.81; R2, 4.7 ± 0.83) and 3D T2w (mean score R1, 4.3 ± 0.82; R2, 4.7 ± 0.69), p = 0.269. Lesion delineation was rated good to excellent for 2D (mean score R1, 4.16 ± 0.81; R2, 4.19 ± 0.92) and 3D T2w (R1, 4.19 ± 0.94; R2, 4.27 ± 0.94) without significant differences (p = 0.785). ROC analysis showed an equivalent performance for 2D (AUC 0.580-0.623) and 3D (AUC 0.576-0.629) T2w (p > 0.05, respectively). Three-dimensional acquisitions demonstrated equivalent image and lesion delineation quality, and PI-RADS v2 performance, compared to 2D in T2-weighted imaging of the prostate. Three-dimensional T2-weighted imaging could be used to considerably shorten prostate MRI protocols in clinical practice. • 3D shows equivalent image quality and lesion delineation compared to 2D T2w. • 3D T2w and 2D T2w image acquisition demonstrated comparable diagnostic performance. • Using a single 3D T2w acquisition may shorten the protocol by 40%. • Combined with short DCE, multiparametric protocols of 10 min are feasible.

  16. Cardiovascular Magnetic Resonance Imaging-Incremental Value in a Series of 361 Patients Demonstrating Cost Savings and Clinical Benefits: An Outcome-Based Study.

    Science.gov (United States)

    Hegde, Vinayak A; Biederman, Robert Ww; Mikolich, J Ronald

    2017-01-01

    This study was designed to assess the clinical impact and cost-benefit of cardiovascular magnetic resonance imaging (CMR). In the face of current health care cost concerns, cardiac imaging modalities have come under focused review. Data related to CMR clinical impact and cost-benefit are lacking. Retrospective review of 361 consecutive patients (pts) who underwent CMR exams was conducted. Indications for CMR were tabulated for appropriateness criteria. Components of the CMR exam were identified along with evidence of clinical impact. The cost of each CMR exam was ascertained along with cost savings attributable to the CMR exam for calculation of an incremental cost-effectiveness ratio. A total of 354 of 361 pts (98%) had diagnostic quality studies. Of the 361 pts, 350 (97%) had at least 1 published Appropriateness Criterion for CMR. A significant clinical impact attributable to CMR exam results was observed in 256 of 361 pts (71%). The CMR exam resulted in a new diagnosis in 69 of 361 (27%) pts. Cardiovascular magnetic resonance imaging results avoided invasive procedures in 38 (11%) pts and prevented additional diagnostic testing in 26 (7%) pts. Comparison of health care savings using CMR as opposed to current standards of care showed a net cost savings of $833 037, ie, per patient cost savings of $2308. Cardiovascular magnetic resonance imaging provides diagnostic image quality in >98% of cases. Cardiovascular magnetic resonance imaging findings have documentable clinical impact on patient management in 71% of pts undergoing the exam, in a cost beneficial manner.

  17. A time-efficient acquisition protocol for multipurpose diffusion-weighted microstructural imaging at 7 Tesla.

    Science.gov (United States)

    Sepehrband, Farshid; O'Brien, Kieran; Barth, Markus

    2017-12-01

    Several diffusion-weighted MRI techniques have been developed and validated during the past 2 decades. While offering various neuroanatomical inferences, these techniques differ in their proposed optimal acquisition design, preventing clinicians and researchers benefiting from all potential inference methods, particularly when limited time is available. This study reports an optimal design that enables for a time-efficient diffusion-weighted MRI acquisition scheme at 7 Tesla. The primary audience of this article is the typical end user, interested in diffusion-weighted microstructural imaging at 7 Tesla. We tested b-values in the range of 700 to 3000 s/mm 2 with different number of angular diffusion-encoding samples, against a data-driven "gold standard." The suggested design is a protocol with b-values of 1000 and 2500 s/mm 2 , with 25 and 50 samples, uniformly distributed over two shells. We also report a range of protocols in which the results of fitting microstructural models to the diffusion-weighted data had high correlation with the gold standard. We estimated minimum acquisition requirements that enable diffusion tensor imaging, higher angular resolution diffusion-weighted imaging, neurite orientation dispersion, and density imaging and white matter tract integrity across whole brain with isotropic resolution of 1.8 mm in less than 11 min. Magn Reson Med 78:2170-2184, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  18. MRI of Creutzfeldt-Jakob disease: Imaging features and recommended MRI protocol

    Energy Technology Data Exchange (ETDEWEB)

    Collie, D.A.; Sellar, R.J.; Zeidler, M.; Colchester, A.C.F.; Knight, R.; Will, R.G

    2001-09-01

    Creutzfeldt-Jakob Disease (CJD) is a rare, progressive and invariably fatal neurodegenerative disease characterized by specific histopathological features. Of the four subtypes of CJD described, the commonest is sporadic CJD (sCJD). More recently, a new clinically distinct form of the disease affecting younger patients, known as variant CJD (vCJD), has been identified, and this has been causally linked to the bovine spongiform encephalopathy (BSE) agent in cattle. Characteristic appearances on magnetic resonance imaging (MRI) have been identified in several forms of CJD; sCJD may be associated with high signal changes in the putamen and caudate head and vCJD is usually associated with hyperintensity of the pulvinar (posterior nuclei) of the thalamus. These appearances and other imaging features are described in this article. Using appropriate clinical and radiological criteria and tailored imaging protocols, MRI plays an important part in the in vivodiagnosis of this disease. Collie, D.A. et al. (2001)

  19. MRI of Creutzfeldt-Jakob disease: Imaging features and recommended MRI protocol

    International Nuclear Information System (INIS)

    Collie, D.A.; Sellar, R.J.; Zeidler, M.; Colchester, A.C.F.; Knight, R.; Will, R.G.

    2001-01-01

    Creutzfeldt-Jakob Disease (CJD) is a rare, progressive and invariably fatal neurodegenerative disease characterized by specific histopathological features. Of the four subtypes of CJD described, the commonest is sporadic CJD (sCJD). More recently, a new clinically distinct form of the disease affecting younger patients, known as variant CJD (vCJD), has been identified, and this has been causally linked to the bovine spongiform encephalopathy (BSE) agent in cattle. Characteristic appearances on magnetic resonance imaging (MRI) have been identified in several forms of CJD; sCJD may be associated with high signal changes in the putamen and caudate head and vCJD is usually associated with hyperintensity of the pulvinar (posterior nuclei) of the thalamus. These appearances and other imaging features are described in this article. Using appropriate clinical and radiological criteria and tailored imaging protocols, MRI plays an important part in the in vivodiagnosis of this disease. Collie, D.A. et al. (2001)

  20. Protocol for the quality control systems of electronic portal imaging used in verification of radiotherapy treatment

    International Nuclear Information System (INIS)

    Silvestre, Ileana; Alfonso, Rodolfo; Garcia, Fernando

    2009-01-01

    Following the approach of quality control of radiotherapy equipment, conceived in the IAEA TECDOC-1151, we analyzed the different tests must be to an EPID to guarantee levels of accuracy required in the administration of radiation treatments, including the study of the impact of different parameters, geometric and dosimetric imaging, involved in the process. Established the types and frequency of checks, as well as procedures for their implementation, the allowable tolerances set of values records and forms for recording . Was carried out assessment protocol in various services based on amorphous silicon EPID for its applicability and scope. Was designed and validated in clinical practice protocol for EPID quality control, demonstrating its applicability with a minimum of material and human resources. It We concluded that with proper and systematic quality control program, tests including dosimetry, the EPID can provide valuable information about physico-beam dosimetry, and ensure adequate accuracy geometric in the patient's location. (author)

  1. A novel strategy to access high resolution DICOM medical images based on JPEG2000 interactive protocol

    Science.gov (United States)

    Tian, Yuan; Cai, Weihua; Sun, Jianyong; Zhang, Jianguo

    2008-03-01

    The demand for sharing medical information has kept rising. However, the transmission and displaying of high resolution medical images are limited if the network has a low transmission speed or the terminal devices have limited resources. In this paper, we present an approach based on JPEG2000 Interactive Protocol (JPIP) to browse high resolution medical images in an efficient way. We designed and implemented an interactive image communication system with client/server architecture and integrated it with Picture Archiving and Communication System (PACS). In our interactive image communication system, the JPIP server works as the middleware between clients and PACS servers. Both desktop clients and wireless mobile clients can browse high resolution images stored in PACS servers via accessing the JPIP server. The client can only make simple requests which identify the resolution, quality and region of interest and download selected portions of the JPEG2000 code-stream instead of downloading and decoding the entire code-stream. After receiving a request from a client, the JPIP server downloads the requested image from the PACS server and then responds the client by sending the appropriate code-stream. We also tested the performance of the JPIP server. The JPIP server runs stably and reliably under heavy load.

  2. Evaluation of a dedicated MDCT protocol using iterative image reconstruction after cervical spine trauma.

    Science.gov (United States)

    Geyer, L L; Körner, M; Hempel, R; Deak, Z; Mueck, F G; Linsenmaier, U; Reiser, M F; Wirth, S

    2013-07-01

    To evaluate radiation exposure for 64-row computed tomography (CT) of the cervical spine comparing two optimized protocols using filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR), respectively. Sixty-seven studies using FBP (scanner 1) were retrospectively compared with 80 studies using ASIR (scanner 2). The key scanning parameters were identical (120 kV dose modulation, 64 × 0.625 mm collimation, pitch 0.531:1). In protocol 2, the noise index (NI) was increased from 5 to 25, and ASIR and the high-definition (HD) mode were used. The scan length, CT dose index (CTDI), and dose-length product (DLP) were recorded. The image quality was analysed subjectively by using a three-point scale (0; 1; 2), and objectively by using a region of interest (ROI) analysis. Mann-Whitney U and Wilcoxon's test were used. In the FBP group, the mean CTDI was 21.43 mGy, mean scan length 186.3 mm, and mean DLP 441.15 mGy cm. In the ASIR group, the mean CTDI was 9.57 mGy, mean scan length 195.21 mm, and mean DLP 204.23 mGy cm. The differences were significant for CTDI and DLP (p 0.05). The estimated mean effective dose decreased from 2.38 mSv (FBP) to 1.10 mSv (ASIR). The radiation dose of 64-row MDCT can be reduced to a level comparable to plain radiography without loss of subjective image quality by implementation of ASIR in a dedicated cervical spine trauma protocol. These results might contribute to an improved relative risk-to-benefit ratio and support the justification of CT as a first-line imaging tool to evaluate cervical spine trauma. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  3. Evaluation of a dedicated MDCT protocol using iterative image reconstruction after cervical spine trauma

    International Nuclear Information System (INIS)

    Geyer, L.L.; Körner, M.; Hempel, R.; Deak, Z.; Mueck, F.G.; Linsenmaier, U.; Reiser, M.F.; Wirth, S.

    2013-01-01

    Aim: To evaluate radiation exposure for 64-row computed tomography (CT) of the cervical spine comparing two optimized protocols using filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR), respectively. Materials and methods: Sixty-seven studies using FBP (scanner 1) were retrospectively compared with 80 studies using ASIR (scanner 2). The key scanning parameters were identical (120 kV dose modulation, 64 × 0.625 mm collimation, pitch 0.531:1). In protocol 2, the noise index (NI) was increased from 5 to 25, and ASIR and the high-definition (HD) mode were used. The scan length, CT dose index (CTDI), and dose–length product (DLP) were recorded. The image quality was analysed subjectively by using a three-point scale (0; 1; 2), and objectively by using a region of interest (ROI) analysis. Mann–Whitney U and Wilcoxon's test were used. Results: In the FBP group, the mean CTDI was 21.43 mGy, mean scan length 186.3 mm, and mean DLP 441.15 mGy cm. In the ASIR group, the mean CTDI was 9.57 mGy, mean scan length 195.21 mm, and mean DLP 204.23 mGy cm. The differences were significant for CTDI and DLP (p 0.05). The estimated mean effective dose decreased from 2.38 mSv (FBP) to 1.10 mSv (ASIR). Conclusion: The radiation dose of 64-row MDCT can be reduced to a level comparable to plain radiography without loss of subjective image quality by implementation of ASIR in a dedicated cervical spine trauma protocol. These results might contribute to an improved relative risk-to-benefit ratio and support the justification of CT as a first-line imaging tool to evaluate cervical spine trauma

  4. Automated assessments of circumferential strain from cine CMR correlate with LVEF declines in cancer patients early after receipt of cardio-toxic chemotherapy.

    Science.gov (United States)

    Jolly, Marie-Pierre; Jordan, Jennifer H; Meléndez, Giselle C; McNeal, Gary R; D'Agostino, Ralph B; Hundley, W Gregory

    2017-08-02

    In patients with cancer receiving potentially cardio-toxic chemotherapy, measurements of left ventricular (LV) circumferential or longitudinal strain are often used clinically to identify myocardial dysfunction. Using a new software algorithm, we sought to determine in individuals receiving treatment for cancer the association between automated assessments of LV mean mid-wall circumferential strain and conventional measures of LV ejection fraction (EF) both obtained from cardiovascular magnetic resonance (CMR) cine balanced steady-state free-precession (bSSFP) white-blood acquisitions. Before and 3 months after initiating treatment with potentially cardio-toxic chemotherapy, 72 individuals (aged 54 ± 14 years with breast cancer [39%], lymphoma [49%], or sarcoma [12%]) underwent serial CMR cine bSSFP assessments of LV volumes and EF, and mean mid-wall circumferential strain determined from these same cine images as well as from additional tagged CMR images. On the cine images, assessments of strain were obtained using the newly developed deformation-based segmentation algorithm. Assessments of LV volumes/EF from the cine images and strain from tagged CMR were accomplished using commercially available software. All measures were analyzed in a blinded fashion independent of one another. Acceptable measures for the automated assessments of mean mid-wall circumferential strain from the cine images were obtained in 142 of 144 visits (98.6%) with an overall analysis time averaging 6:47 ± 1:06 min. The results from these automated measures averaged -18.8 ± 2.9 at baseline and -17.6 ± 3.1 at 3 months (p = 0.001). Left ventricular EF declined slightly from 65 ± 7% at baseline to 62 ± 7% at 3 months (p = 0.0002). The correlation between strain from cine imaging and LVEF was r = -0.61 (p cine and tagged derived assessments of strain was r = 0.23; p = 0.01. Automated measures of LV mean mid-wall circumferential strain can be obtained in 6

  5. CRISPR/Cas and Cmr modules, mobility and evolution of adaptive immune systems

    DEFF Research Database (Denmark)

    Shah, Shiraz Ali; Garrett, Roger Antony

    2011-01-01

    CRISPR/Cas and CRISPR/Cmr immune machineries of archaea and bacteria provide an adaptive and effective defence mechanism directed specifically against viruses and plasmids. Present data suggest that both CRISPR/Cas and Cmr modules can behave like integral genetic elements. They tend to be located...... in the more variable regions of chromosomes and are displaced by genome shuffling mechanisms including transposition. CRISPR loci may be broken up and dispersed in chromosomes by transposons with the potential for creating genetic novelty. Both CRISPR/Cas and Cmr modules appear to exchange readily between...... the significant barriers imposed by their differing conjugative, transcriptional and translational mechanisms. There are parallels between the CRISPR crRNAs and eukaryal siRNAs, most notably to germ cell piRNAs which are directed, with the help of effector proteins, to silence or destroy transposons...

  6. Dynamic whole body PET parametric imaging: I. Concept, acquisition protocol optimization and clinical application

    Science.gov (United States)

    Karakatsanis, Nicolas A.; Lodge, Martin A.; Tahari, Abdel K.; Zhou, Y.; Wahl, Richard L.; Rahmim, Arman

    2013-01-01

    Static whole body PET/CT, employing the standardized uptake value (SUV), is considered the standard clinical approach to diagnosis and treatment response monitoring for a wide range of oncologic malignancies. Alternative PET protocols involving dynamic acquisition of temporal images have been implemented in the research setting, allowing quantification of tracer dynamics, an important capability for tumor characterization and treatment response monitoring. Nonetheless, dynamic protocols have been confined to single bed-coverage limiting the axial field-of-view to ~15–20 cm, and have not been translated to the routine clinical context of whole-body PET imaging for the inspection of disseminated disease. Here, we pursue a transition to dynamic whole body PET parametric imaging, by presenting, within a unified framework, clinically feasible multi-bed dynamic PET acquisition protocols and parametric imaging methods. We investigate solutions to address the challenges of: (i) long acquisitions, (ii) small number of dynamic frames per bed, and (iii) non-invasive quantification of kinetics in the plasma. In the present study, a novel dynamic (4D) whole body PET acquisition protocol of ~45min total length is presented, composed of (i) an initial 6-min dynamic PET scan (24 frames) over the heart, followed by (ii) a sequence of multi-pass multi-bed PET scans (6 passes x 7 bed positions, each scanned for 45sec). Standard Patlak linear graphical analysis modeling was employed, coupled with image-derived plasma input function measurements. Ordinary least squares (OLS) Patlak estimation was used as the baseline regression method to quantify the physiological parameters of tracer uptake rate Ki and total blood distribution volume V on an individual voxel basis. Extensive Monte Carlo simulation studies, using a wide set of published kinetic FDG parameters and GATE and XCAT platforms, were conducted to optimize the acquisition protocol from a range of 10 different clinically

  7. Dynamic whole-body PET parametric imaging: I. Concept, acquisition protocol optimization and clinical application.

    Science.gov (United States)

    Karakatsanis, Nicolas A; Lodge, Martin A; Tahari, Abdel K; Zhou, Y; Wahl, Richard L; Rahmim, Arman

    2013-10-21

    Static whole-body PET/CT, employing the standardized uptake value (SUV), is considered the standard clinical approach to diagnosis and treatment response monitoring for a wide range of oncologic malignancies. Alternative PET protocols involving dynamic acquisition of temporal images have been implemented in the research setting, allowing quantification of tracer dynamics, an important capability for tumor characterization and treatment response monitoring. Nonetheless, dynamic protocols have been confined to single-bed-coverage limiting the axial field-of-view to ~15-20 cm, and have not been translated to the routine clinical context of whole-body PET imaging for the inspection of disseminated disease. Here, we pursue a transition to dynamic whole-body PET parametric imaging, by presenting, within a unified framework, clinically feasible multi-bed dynamic PET acquisition protocols and parametric imaging methods. We investigate solutions to address the challenges of: (i) long acquisitions, (ii) small number of dynamic frames per bed, and (iii) non-invasive quantification of kinetics in the plasma. In the present study, a novel dynamic (4D) whole-body PET acquisition protocol of ~45 min total length is presented, composed of (i) an initial 6 min dynamic PET scan (24 frames) over the heart, followed by (ii) a sequence of multi-pass multi-bed PET scans (six passes × seven bed positions, each scanned for 45 s). Standard Patlak linear graphical analysis modeling was employed, coupled with image-derived plasma input function measurements. Ordinary least squares Patlak estimation was used as the baseline regression method to quantify the physiological parameters of tracer uptake rate Ki and total blood distribution volume V on an individual voxel basis. Extensive Monte Carlo simulation studies, using a wide set of published kinetic FDG parameters and GATE and XCAT platforms, were conducted to optimize the acquisition protocol from a range of ten different clinically

  8. Dynamic whole-body PET parametric imaging: I. Concept, acquisition protocol optimization and clinical application

    International Nuclear Information System (INIS)

    Karakatsanis, Nicolas A; Lodge, Martin A; Tahari, Abdel K; Zhou, Y; Wahl, Richard L; Rahmim, Arman

    2013-01-01

    Static whole-body PET/CT, employing the standardized uptake value (SUV), is considered the standard clinical approach to diagnosis and treatment response monitoring for a wide range of oncologic malignancies. Alternative PET protocols involving dynamic acquisition of temporal images have been implemented in the research setting, allowing quantification of tracer dynamics, an important capability for tumor characterization and treatment response monitoring. Nonetheless, dynamic protocols have been confined to single-bed-coverage limiting the axial field-of-view to ∼15–20 cm, and have not been translated to the routine clinical context of whole-body PET imaging for the inspection of disseminated disease. Here, we pursue a transition to dynamic whole-body PET parametric imaging, by presenting, within a unified framework, clinically feasible multi-bed dynamic PET acquisition protocols and parametric imaging methods. We investigate solutions to address the challenges of: (i) long acquisitions, (ii) small number of dynamic frames per bed, and (iii) non-invasive quantification of kinetics in the plasma. In the present study, a novel dynamic (4D) whole-body PET acquisition protocol of ∼45 min total length is presented, composed of (i) an initial 6 min dynamic PET scan (24 frames) over the heart, followed by (ii) a sequence of multi-pass multi-bed PET scans (six passes × seven bed positions, each scanned for 45 s). Standard Patlak linear graphical analysis modeling was employed, coupled with image-derived plasma input function measurements. Ordinary least squares Patlak estimation was used as the baseline regression method to quantify the physiological parameters of tracer uptake rate K i and total blood distribution volume V on an individual voxel basis. Extensive Monte Carlo simulation studies, using a wide set of published kinetic FDG parameters and GATE and XCAT platforms, were conducted to optimize the acquisition protocol from a range of ten different

  9. Dynamic whole-body PET parametric imaging: I. Concept, acquisition protocol optimization and clinical application

    Science.gov (United States)

    Karakatsanis, Nicolas A.; Lodge, Martin A.; Tahari, Abdel K.; Zhou, Y.; Wahl, Richard L.; Rahmim, Arman

    2013-10-01

    Static whole-body PET/CT, employing the standardized uptake value (SUV), is considered the standard clinical approach to diagnosis and treatment response monitoring for a wide range of oncologic malignancies. Alternative PET protocols involving dynamic acquisition of temporal images have been implemented in the research setting, allowing quantification of tracer dynamics, an important capability for tumor characterization and treatment response monitoring. Nonetheless, dynamic protocols have been confined to single-bed-coverage limiting the axial field-of-view to ˜15-20 cm, and have not been translated to the routine clinical context of whole-body PET imaging for the inspection of disseminated disease. Here, we pursue a transition to dynamic whole-body PET parametric imaging, by presenting, within a unified framework, clinically feasible multi-bed dynamic PET acquisition protocols and parametric imaging methods. We investigate solutions to address the challenges of: (i) long acquisitions, (ii) small number of dynamic frames per bed, and (iii) non-invasive quantification of kinetics in the plasma. In the present study, a novel dynamic (4D) whole-body PET acquisition protocol of ˜45 min total length is presented, composed of (i) an initial 6 min dynamic PET scan (24 frames) over the heart, followed by (ii) a sequence of multi-pass multi-bed PET scans (six passes × seven bed positions, each scanned for 45 s). Standard Patlak linear graphical analysis modeling was employed, coupled with image-derived plasma input function measurements. Ordinary least squares Patlak estimation was used as the baseline regression method to quantify the physiological parameters of tracer uptake rate Ki and total blood distribution volume V on an individual voxel basis. Extensive Monte Carlo simulation studies, using a wide set of published kinetic FDG parameters and GATE and XCAT platforms, were conducted to optimize the acquisition protocol from a range of ten different clinically

  10. Imaging techniques and investigation protocols in pediatric emergency imaging; Aufnahmetechnik und Untersuchungsprotokolle beim paediatrischen Notfall

    Energy Technology Data Exchange (ETDEWEB)

    Scharitzer, M.; Hoermann, M.; Puig, S.; Prokop, M. [Universitaetsklinik fuer Radiodiagnostik, Wien (Austria)

    2002-03-01

    Paediatric emergencies demand a quick and efficient radiological investigation with special attention to specific adjustments related to patient age and radiation protection. Imaging modalities are improving rapidly and enable to diagnose childhood diseases and injuries more quickly, accurately and safely. This article provides an overview of imaging techniques adjusted to the age of the child and an overview of imaging strategies of common paediatric emergencies. Optimising the imaging parameters (digital radiography, different screen-film systems, exposure specifications) allows for substantial reduction of radiation dose. Spiral- and multislice-CT reduce scan time and enable a considerable reduction of radiation exposure if scanning parameters (pitch setting, tube current) are properly adjusted. MRI is still mainly used for neurological or spinal emergencies despite the advent of fast imaging sequences. The radiologist's task is to select an appropriate imaging strategy according to expected differential diagnosis and to adjust the imaging techniques to the individual patient. (orig.) [German] Das akut erkrankte Kind erfordert eine rasche radiologische Abklaerung mit besonderer Beruecksichtung der geaenderten Untersuchungsparameter bei gleichzeitig hohem Anspruch an den Strahlenschutz. Hochaufloesende Schallkoepfe, Multislice-CT und schnelle MR-Sequenzen erlauben eine bessere Anpassung der Untersuchungsmethoden an die Beduerfnisse in der Kinderradiologie. Ziel dieses Artikels ist eine Uebersicht ueber die verschiedenen radiologischen Untersuchungstechniken sowie deren Anpassung an kindliche Anforderungen und die Angabe von Untersuchungsalgorithmen der haeufigsten paediatrischen Notfaelle. In der Projektionsradiographie erlaubt die Optimierung der Aufnahmetechnik (digitale Radiographie, unterschiedliche Klassen von Film-Folien-Systemen, Belichtungsparameter) eine deutliche Reduktion der Strahlendosis bei diagnostisch ausreichender Qualitaet. Spiral- oder

  11. Evaluation of Pulmonary Hypertension with CMR: Pulmonary Hypertension 
Patients and Healthy Volunteers Control Study

    Directory of Open Access Journals (Sweden)

    Meng WANG

    2016-05-01

    Full Text Available Background and objective The clinical course of pulmonary hypertension (PH is one of progressive deterioration interspersed with episodes of acute decompensation. It is difficult to predict when patients will die because death may come either suddenly or slowly due to progressive heart failure. The aim of this study is to investigate morphology, function and hemodynamics in PH, compared with healthy people, and to investigate the clinical value of detection of PH by use of cardiac magnetic resonance (CMR parameters. Methods CMR was performed in 56 PH patients collected from Tianjin Medical University General Hospital from January 2012 to December 2014 and 22 healthy controls. The following parameters were calculated: right ventricle (RV end-diastolic volume (EDV, end-systolic volume (ESV, ejection fraction (EF, myocardial mass (MM, RV fractional area change (RVFAC, interventricular septal curvature (CIVS, left ventricular free wall curvature (CFW, and CIVS/CFW, main pulmonary artery (MPA positive peak velocity, maximal area, minimal area and distensibility. Comparisons of CMR measurements between PH patients and controls were analyzed by using the student t-tests. Receiver operating characteristic (ROC curve analysis was used to compare the PH diagnostic abilities for four parameters (MPA positive peak velocity, distensibility, curvature ratio, and RVFAC and combined CMR parameter. P<0.05 was considered significant. Results Compared with healthy controls, RV morphology, function and hemodynamics of PH group declined and deteriorate obviously. The ROC curve analysis showed that among the four parameters distensibility of MPA had the highest AUC value (AUC=0.95. Additionally, combined CMR parameter (positive peak velocity+distensibility+curvature ratio+RVFAC had even higher AUC (AUC=0.988. Conclusion Comprehensive CMR parameters is conducive to accurately reflect the overall state RV-pulmonary circulation in patients with PH.

  12. Positron emission tomography/computed tomography--imaging protocols, artifacts, and pitfalls.

    Science.gov (United States)

    Bockisch, Andreas; Beyer, Thomas; Antoch, Gerald; Freudenberg, Lutz S; Kühl, Hilmar; Debatin, Jörg F; Müller, Stefan P

    2004-01-01

    There has been a longstanding interest in fused images of anatomical information, such as that provided by computed tomography (CT) or magnetic resonance imaging (MRI) systems, with biological information obtainable by positron emission tomography (PET). The near-simultaneous data acquisition in a fixed combination of a PET and a CT scanner in a combined PET/CT imaging system minimizes spatial and temporal mismatches between the modalities by eliminating the need to move the patient in between exams. In addition, using the fast CT scan for PET attenuation correction, the duration of the examination is significantly reduced compared to standalone PET imaging with standard rod-transmission sources. The main source of artifacts arises from the use of the CT-data for scatter and attenuation correction of the PET images. Today, CT reconstruction algorithms cannot account for the presence of metal implants, such as dental fillings or prostheses, properly, thus resulting in streak artifacts, which are propagated into the PET image by the attenuation correction. The transformation of attenuation coefficients at X-ray energies to those at 511 keV works well for soft tissues, bone, and air, but again is insufficient for dense CT contrast agents, such as iodine or barium. Finally, mismatches, for example, due to uncoordinated respiration result in incorrect attenuation-corrected PET images. These artifacts, however, can be minimized or avoided prospectively by careful acquisition protocol considerations. In doubt, the uncorrected images almost always allow discrimination between true and artificial finding. PET/CT has to be integrated into the diagnostic workflow for harvesting the full potential of the new modality. In particular, the diagnostic power of both, the CT and the PET within the combination must not be underestimated. By combining multiple diagnostic studies within a single examination, significant logistic advantages can be expected if the combined PET

  13. Experimental protocols for behavioral imaging: seeing animal models of drug abuse in a new light.

    Science.gov (United States)

    Aarons, Alexandra R; Talan, Amanda; Schiffer, Wynne K

    2012-01-01

    Behavioral neuroimaging is a rapidly evolving discipline that represents a marriage between the fields of behavioral neuroscience and preclinical molecular imaging. This union highlights the changing role of imaging in translational research. Techniques developed for humans are now widely applied in the study of animal models of brain disorders such as drug addiction. Small animal or preclinical imaging allows us to interrogate core features of addiction from both behavioral and biological endpoints. Snapshots of brain activity allow us to better understand changes in brain function and behavior associated with initial drug exposure, the emergence of drug escalation, and repeated bouts of drug withdrawal and relapse. Here we review the development and validation of new behavioral imaging paradigms and several clinically relevant radiotracers used to capture dynamic molecular events in behaving animals. We will discuss ways in which behavioral imaging protocols can be optimized to increase throughput and quantitative methods. Finally, we discuss our experience with the practical aspects of behavioral neuroimaging, so investigators can utilize effective animal models to better understand the addicted brain and behavior.

  14. Improved image quality and radiation dose reduction in liver dynamic CT scan with the protocol change

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yu Jin; Cho, Pyong Kon [Radiological Science, Catholic University of Daegu, Daegu (Korea, Republic of)

    2015-06-15

    The purpose is reducing radiation dose while maintaining of image quality in liver dynamic CT(LDCT) scan, by protocols generally used and the tube voltage set at a low level protocol compared to the radiation dose and image quality. The target is body mass index, 18.5-24 patients out of 40 patients who underwent the ACT(abdominal CT). Group A(tube voltage : 120 kVp, SAFIRE strength 1) of 20 people among 40 people, to apply the general abdominal CT scan protocol, group B(tube voltage : 100 kVp, apply SAFIRE strength 0-5) was 20 people, set a lower tube voltage. Image quality evaluation was setting a region of interest(ROI) in the liver parenchyma, aorta, superior mesenteric artery (SMA), celiac trunk, visceral fat of arterial phase. In the ROI were compared by measuring the noise, signal to noise ratio(SNR), contrast to noise ratio(CNR), CT number. In addition, qualitative assessments to evaluate two people in the rich professional experience in Radiology by 0-3 points. We compared the total radiation dose, dose length product(DLP) and effective dose, volume computed tomography dose index(CTDIvol). The higher SAFIRE in the tube voltage 100 kVp, noise is reduced, CT number was increased. Thus, SNR and CNR was increased higher the SAFIRE step. Compared with the tube voltage 120 kVp, noise, SNR, CNR was most similar in SAFIRE strength 2 and 3. Qualitative assessment SAFIRE strength 2 is the most common SAFIRE strength 2 the most common qualitative assessment, if the tube voltage of 100 kVp when the quality of the images better evaluated was SAFIRE strength 1. Dose was reduced from 21.69%, in 100 kVp than 120 kVp. In the case of a relatively high BMI is not LDCT scan, When it is shipped from the factory tube voltage is set higher, unnecessary radiation exposure when considering the reality that is concerned, when according to the results of this study, set a lower tube voltage and adjust the SAFIRE strength to 1 or 2, the radiation without compromising image quality

  15. A standardized imaging protocol for the endoscopic prediction of dysplasia within sessile serrated polyps (with video).

    Science.gov (United States)

    Tate, David J; Jayanna, Mahesh; Awadie, Halim; Desomer, Lobke; Lee, Ralph; Heitman, Steven J; Sidhu, Mayenaaz; Goodrick, Kathleen; Burgess, Nicholas G; Mahajan, Hema; McLeod, Duncan; Bourke, Michael J

    2018-01-01

    Dysplasia within sessile serrated polyps (SSPs) is difficult to detect and may be mistaken for an adenoma, risking incomplete resection of the background serrated tissue, and is strongly implicated in interval cancer after colonoscopy. The use of endoscopic imaging to detect dysplasia within SSPs has not been systematically studied. Consecutively detected SSPs ≥8 mm in size were evaluated by using a standardized imaging protocol at a tertiary-care endoscopy center over 3 years. Lesions suspected as SSPs were analyzed with high-definition white light then narrow-band imaging. A demarcated area with a neoplastic pit pattern (Kudo type III/IV, NICE type II) was sought among the serrated tissue. If this was detected, the lesion was labeled dysplastic (sessile serrated polyp with dysplasia); if not, it was labeled non-dysplastic (sessile serrated polyp without dysplasia). Histopathology was reviewed by 2 blinded specialist GI pathologists. A total of 141 SSPs were assessed in 83 patients. Median lesion size was 15.0 mm (interquartile range 10-20), and 54.6% were in the right side of the colon. Endoscopic evidence of dysplasia was detected in 36 of 141 (25.5%) SSPs; of these, 5 of 36 (13.9%) lacked dysplasia at histopathology. Two of 105 (1.9%) endoscopically designated non-dysplastic SSPs had dysplasia at histopathology. Endoscopic imaging, therefore, had an accuracy of 95.0% (95% confidence interval [CI], 90.1%-97.6%) and a negative predictive value of 98.1% (95% CI, 92.6%-99.7%) for detection of dysplasia within SSPs. Dysplasia within SSPs can be detected accurately by using a simple, broadly applicable endoscopic imaging protocol that allows complete resection. Independent validation of this protocol and its dissemination to the wider endoscopic community may have a significant impact on rates of interval cancer. (Clinical trial registration number: NCT03100552.). Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All

  16. Adapting protocols of CT imaging in a pediatric emergency department. Evaluation of image quality and dose

    International Nuclear Information System (INIS)

    Batista Arce, A.; Gonzalez Lopez, S.; Catalan Acosta, A.; Casares Magaz, O.; Hernandez Armas, O.; Hernandez Armas, J.

    2011-01-01

    The purpose of this study was to assess qualitatively the picture quality in relation to the radiation dose delivered in CT studies of computer tomograph Pediatric Emergency Department of Hospital Universitario de Canarias (HUC) in order to optimize the technical parameters used these radiological examinations so as to obtain optimal image quality at the lowest possible dose.

  17. An Experimental Protocol for Assessing the Performance of New Ultrasound Probes Based on CMUT Technology in Application to Brain Imaging.

    Science.gov (United States)

    Matrone, Giulia; Ramalli, Alessandro; Savoia, Alessandro Stuart; Quaglia, Fabio; Castellazzi, Gloria; Morbini, Patrizia; Piastra, Marco

    2017-09-24

    The possibility to perform an early and repeatable assessment of imaging performance is fundamental in the design and development process of new ultrasound (US) probes. Particularly, a more realistic analysis with application-specific imaging targets can be extremely valuable to assess the expected performance of US probes in their potential clinical field of application. The experimental protocol presented in this work was purposely designed to provide an application-specific assessment procedure for newly-developed US probe prototypes based on Capacitive Micromachined Ultrasonic Transducer (CMUT) technology in relation to brain imaging. The protocol combines the use of a bovine brain fixed in formalin as the imaging target, which ensures both realism and repeatability of the described procedures, and of neuronavigation techniques borrowed from neurosurgery. The US probe is in fact connected to a motion tracking system which acquires position data and enables the superposition of US images to reference Magnetic Resonance (MR) images of the brain. This provides a means for human experts to perform a visual qualitative assessment of the US probe imaging performance and to compare acquisitions made with different probes. Moreover, the protocol relies on the use of a complete and open research and development system for US image acquisition, i.e. the Ultrasound Advanced Open Platform (ULA-OP) scanner. The manuscript describes in detail the instruments and procedures involved in the protocol, in particular for the calibration, image acquisition and registration of US and MR images. The obtained results prove the effectiveness of the overall protocol presented, which is entirely open (within the limits of the instrumentation involved), repeatable, and covers the entire set of acquisition and processing activities for US images.

  18. GUI implementation of image encryption and decryption using Open CV-Python script on secured TFTP protocol

    Science.gov (United States)

    Reddy, K. Rasool; Rao, Ch. Madhava

    2018-04-01

    Currently safety is one of the primary concerns in the transmission of images due to increasing the use of images within the industrial applications. So it's necessary to secure the image facts from unauthorized individuals. There are various strategies are investigated to secure the facts. In that encryption is certainly one of maximum distinguished method. This paper gives a sophisticated Rijndael (AES) algorithm to shield the facts from unauthorized humans. Here Exponential Key Change (EKE) concept is also introduced to exchange the key between client and server. The things are exchange in a network among client and server through a simple protocol is known as Trivial File Transfer Protocol (TFTP). This protocol is used mainly in embedded servers to transfer the data and also provide protection to the data if protection capabilities are integrated. In this paper, implementing a GUI environment for image encryption and decryption. All these experiments carried out on Linux environment the usage of Open CV-Python script.

  19. 101 labeled brain images and a consistent human cortical labeling protocol

    Directory of Open Access Journals (Sweden)

    Arno eKlein

    2012-12-01

    Full Text Available We introduce the Mindboggle-101 dataset, the largest and most complete set of free, publicly accessible, manually labeled human brain images. To manually label the macroscopic anatomy in magnetic resonance images of 101 healthy participants, we created a new cortical labeling protocol that relies on robust anatomical landmarks and minimal manual edits after initialization with automated labels. The Desikan-Killiany-Tourville (DKT protocol is intended to improve the ease, consistency, and accuracy of labeling human cortical areas. Given how difficult it is to label brains, the Mindboggle-101 dataset is intended to serve as brain atlases for use in labeling other brains, as a normative dataset to establish morphometric variation in a healthy population for comparison against clinical populations, and contribute to the development, training, testing, and evaluation of automated registration and labeling algorithms. To this end, we also introduce benchmarks for the evaluation of such algorithms by comparing our manual labels with labels automatically generated by probabilistic and multi-atlas registration-based approaches. All data and related software and updated information are available on the http://www.mindboggle.info/data/ website.

  20. 101 Labeled Brain Images and a Consistent Human Cortical Labeling Protocol

    Science.gov (United States)

    Klein, Arno; Tourville, Jason

    2012-01-01

    We introduce the Mindboggle-101 dataset, the largest and most complete set of free, publicly accessible, manually labeled human brain images. To manually label the macroscopic anatomy in magnetic resonance images of 101 healthy participants, we created a new cortical labeling protocol that relies on robust anatomical landmarks and minimal manual edits after initialization with automated labels. The “Desikan–Killiany–Tourville” (DKT) protocol is intended to improve the ease, consistency, and accuracy of labeling human cortical areas. Given how difficult it is to label brains, the Mindboggle-101 dataset is intended to serve as brain atlases for use in labeling other brains, as a normative dataset to establish morphometric variation in a healthy population for comparison against clinical populations, and contribute to the development, training, testing, and evaluation of automated registration and labeling algorithms. To this end, we also introduce benchmarks for the evaluation of such algorithms by comparing our manual labels with labels automatically generated by probabilistic and multi-atlas registration-based approaches. All data and related software and updated information are available on the http://mindboggle.info/data website. PMID:23227001

  1. Performance evaluation of secured DICOM image communication with next generation internet protocol IPv6

    Science.gov (United States)

    Yu, Fenghai; Zhang, Jianguo; Chen, Xiaomeng; Huang, H. K.

    2005-04-01

    Next Generation Internet (NGI) technology with new communication protocol IPv6 emerges as a potential solution for low-cost and high-speed networks for image data transmission. IPv6 is designed to solve many of the problems of the current version of IP (known as IPv4) with regard to address depletion, security, autoconfiguration, extensibility, and more. We choose CTN (Central Test Node) DICOM software developed by The Mallinckrodt Institute of Radiology to implement IPv6/IPv4 enabled DICOM communication software on different operating systems (Windows/Linux), and used this DICOM software to evaluate the performance of the IPv6/IPv4 enabled DICOM image communication with different security setting and environments. We compared the security communications of IPsec with SSL/TLS on different TCP/IP protocols (IPv6/IPv4), and find that there are some trade-offs to choose security solution between IPsec and SSL/TLS in the security implementation of IPv6/IPv4 communication networks.

  2. Safety of adenosine stress myocardial perfusion imaging by a one-route infusion protocol

    International Nuclear Information System (INIS)

    Kawai, Yuko; Kishino, Koh

    2006-01-01

    When adenosine stress testing is performed, a vein is generally accessed in each arm. To determine whether the one-route infusion protocol, that is, infusion via one upper arm vein, is safe, myocardial perfusion imaging was performed during adenosine stress testing in patients with angina pectoris. Sixty-six consecutive patients (43 men, 68±11 years of age) with suspected coronary artery disease were enrolled in this study. For the stress test, adenosine was injected at 120 μg/kg/min for 6 minutes. Systolic blood pressure, diastolic blood pressure, and heart rate did not show any significant changes after injection of the adenosine and radioisotope (RI) tracer. Adverse events during infusion of the adenosine were seen in 42 (64%) patients and included chest discomfort/oppression in 17 (26%) and dyspnea/throat discomfort in 15 (23%). On the other hand, adverse events just after infusion of the RI tracer occurred in 5 (8%) patients and included chest oppression in 2 (3%) and dyspnea in 1 (2%). Almost all adverse events disappeared quickly without treatment. Therefore, we concluded that adenosine stress myocardial perfusion imaging using a one-route infusion protocol is safe and useful to do for patients unable to secure veins in both arms. (author)

  3. Triple rule-out CT in the emergency department: protocols and spectrum of imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Frauenfelder, Thomas; Appenzeller, Philippe; Karlo, Christoph; Scheffel, Hans; Desbiolles, Lotus; Stolzmann, Paul; Marincek, Borut; Alkadhi, Hatem; Schertler, Thomas [University Hospital Zurich, Department of Medical Radiology, Institute of Diagnostic Radiology, Zurich (Switzerland)

    2009-04-15

    Triage decisions in patients suffering from acute chest pain remain a challenge. The patient's history, initial cardiac enzyme levels, or initial electrocardiograms (ECG) often do not allow selecting the patients in whom further tests are needed. Numerous vascular and non-vascular chest problems, such as pulmonary embolism (PE), aortic dissection, or acute coronary syndrome, as well as pulmonary, pleural, or osseous lesions, must be taken into account. Nowadays, contrast-enhanced multi-detector-row computed tomography (CT) has replaced previous invasive diagnostic procedures and currently represents the imaging modality of choice when the clinical suspicion of PE or acute aortic syndrome is raised. At the same time, CT is capable of detecting a multitude of non-vascular causes of acute chest pain, such as pneumonia, pericarditis, or fractures. Recent technical advances in CT technology have also shown great advantages for non-invasive imaging of the coronary arteries. In patients with acute chest pain, the optimization of triage decisions and cost-effectiveness using cardiac CT in the emergency department have been repetitively demonstrated. Triple rule-out CT denominates an ECG-gated protocol that allows for the depiction of the pulmonary arteries, thoracic aorta, and coronary arteries within a single examination. This can be accomplished through the use of a dedicated contrast media administration regimen resulting in a simultaneous attenuation of the three vessel territories. This review is intended to demonstrate CT parameters and contrast media administration protocols for performing a triple rule-out CT and discusses radiation dose issues pertinent to the protocol. Typical life-threatening and non-life-threatening diseases causing acute chest pain are illustrated. (orig.)

  4. DICOM image secure communications with Internet protocols IPv6 and IPv4.

    Science.gov (United States)

    Zhang, Jianguo; Yu, Fenghai; Sun, Jianyong; Yang, Yuanyuan; Liang, Chenwen

    2007-01-01

    Image-data transmission from one site to another through public network is usually characterized in term of privacy, authenticity, and integrity. In this paper, we first describe a general scenario about how image is delivered from one site to another through a wide-area network (WAN) with security features of data privacy, integrity, and authenticity. Second, we give the common implementation method of the digital imaging and communication in medicine (DICOM) image communication software library with IPv6/IPv4 for high-speed broadband Internet by using open-source software. Third, we discuss two major security-transmission methods, the IP security (IPSec) and the secure-socket layer (SSL) or transport-layer security (TLS), being used currently in medical-image-data communication with privacy support. Fourth, we describe a test schema of multiple-modality DICOM-image communications through TCP/IPv4 and TCP/IPv6 with different security methods, different security algorithms, and operating systems, and evaluate the test results. We found that there are tradeoff factors between choosing the IPsec and the SSL/TLS-based security implementation of IPv6/IPv4 protocols. If the WAN networks only use IPv6 such as in high-speed broadband Internet, the choice is IPsec-based security. If the networks are IPv4 or the combination of IPv6 and IPv4, it is better to use SSL/TLS security. The Linux platform has more security algorithms implemented than the Windows (XP) platform, and can achieve better performance in most experiments of IPv6 and IPv4-based DICOM-image communications. In teleradiology or enterprise-PACS applications, the Linux operating system may be the better choice as peer security gateways for both the IPsec and the SSL/TLS-based secure DICOM communications cross public networks.

  5. Magnetic resonance imaging of third molars: developing a protocol suitable for forensic age estimation.

    Science.gov (United States)

    De Tobel, Jannick; Hillewig, Elke; Bogaert, Stephanie; Deblaere, Karel; Verstraete, Koenraad

    2017-03-01

    Established dental age estimation methods in sub-adults study the development of third molar root apices on radiographs. In living individuals, however, avoiding ionising radiation is expedient. Studying dental development with magnetic resonance imaging complies with this requirement, adding the advantage of imaging in three dimensions. To elaborate the development of an MRI protocol to visualise all third molars for forensic age estimation, with particular attention to the development of the root apex. Ex vivo scans of porcine jaws and in vivo scans of 10 volunteers aged 17-25 years were performed to select adequate sequences. Studied parameters were T1 vs T2 weighting, ultrashort echo time (UTE), fat suppression, in plane resolution, slice thickness, 3D imaging, signal-to-noise ratio, and acquisition time. A bilateral four-channel flexible surface coil was used. Two observers evaluated the suitability of the images. T2-weighted images were preferred to T1-weighted images. To clearly distinguish root apices in (almost) fully developed third molars an in plane resolution of 0.33 × 0.33 mm 2 was deemed necessary. Taking acquisition time limits into account, only a T2 FSE sequence with slice thickness of 2 mm generated images with sufficient resolution and contrast. UTE, thinner slice T2 FSE and T2 3D FSE sequences could not generate the desired resolution within 6.5 minutes. Three Tesla MRI of the third molars is a feasible technique for forensic age estimation, in which a T2 FSE sequence can provide the desired in plane resolution within a clinically acceptable acquisition time.

  6. Involvement of phenazines and biosurfactants in biocontrol of Pythium myriotylum root rot on cocoyam by Pseudomonas sp. CMR12A

    Science.gov (United States)

    Pseudomonas sp. CMR12a was isolated from the rhizosphere of the tropical tuber crop cocoyam and produces both phenazines and cyclic lipopeptide (CLP) biosurfactants. CMR12a was shown to be an efficient biocontrol agent of P. myriotylum on cocoyam. To assess the importance of phenazine and biosurfact...

  7. Constructing Benchmark Databases and Protocols for Medical Image Analysis: Diabetic Retinopathy

    Directory of Open Access Journals (Sweden)

    Tomi Kauppi

    2013-01-01

    Full Text Available We address the performance evaluation practices for developing medical image analysis methods, in particular, how to establish and share databases of medical images with verified ground truth and solid evaluation protocols. Such databases support the development of better algorithms, execution of profound method comparisons, and, consequently, technology transfer from research laboratories to clinical practice. For this purpose, we propose a framework consisting of reusable methods and tools for the laborious task of constructing a benchmark database. We provide a software tool for medical image annotation helping to collect class label, spatial span, and expert's confidence on lesions and a method to appropriately combine the manual segmentations from multiple experts. The tool and all necessary functionality for method evaluation are provided as public software packages. As a case study, we utilized the framework and tools to establish the DiaRetDB1 V2.1 database for benchmarking diabetic retinopathy detection algorithms. The database contains a set of retinal images, ground truth based on information from multiple experts, and a baseline algorithm for the detection of retinopathy lesions.

  8. Specimen preparation, imaging, and analysis protocols for knife-edge scanning microscopy.

    Science.gov (United States)

    Choe, Yoonsuck; Mayerich, David; Kwon, Jaerock; Miller, Daniel E; Sung, Chul; Chung, Ji Ryang; Huffman, Todd; Keyser, John; Abbott, Louise C

    2011-12-09

    Major advances in high-throughput, high-resolution, 3D microscopy techniques have enabled the acquisition of large volumes of neuroanatomical data at submicrometer resolution. One of the first such instruments producing whole-brain-scale data is the Knife-Edge Scanning Microscope (KESM), developed and hosted in the authors' lab. KESM has been used to section and image whole mouse brains at submicrometer resolution, revealing the intricate details of the neuronal networks (Golgi), vascular networks (India ink), and cell body distribution (Nissl). The use of KESM is not restricted to the mouse nor the brain. We have successfully imaged the octopus brain, mouse lung, and rat brain. We are currently working on whole zebra fish embryos. Data like these can greatly contribute to connectomics research; to microcirculation and hemodynamic research; and to stereology research by providing an exact ground-truth. In this article, we will describe the pipeline, including specimen preparation (fixing, staining, and embedding), KESM configuration and setup, sectioning and imaging with the KESM, image processing, data preparation, and data visualization and analysis. The emphasis will be on specimen preparation and visualization/analysis of obtained KESM data. We expect the detailed protocol presented in this article to help broaden the access to KESM and increase its utilization.

  9. Acquisition and Processing Protocols for Uav Images: 3d Modeling of Historical Buildings Using Photogrammetry

    Science.gov (United States)

    Murtiyoso, A.; Koehl, M.; Grussenmeyer, P.; Freville, T.

    2017-08-01

    Photogrammetry has seen an increase in the use of UAVs (Unmanned Aerial Vehicles) for both large and smaller scale cartography. The use of UAVs is also advantageous because it may be used for tasks requiring quick response, including in the case of the inspection and monitoring of buildings. The objective of the project is to study the acquisition and processing protocols which exist in the literature and to adapt them for UAV projects. This implies a study on the calibration of the sensors, flight planning, comparison of software solutions, data management, and analysis on the different products of a UAV project. Two historical buildings of the city of Strasbourg were used as case studies: a part of the Rohan Palace façade and the St-Pierre-le-Jeune Catholic church. In addition, a preliminary test was performed on the Josephine Pavilion. Two UAVs were used in this research; namely the Sensefly Albris and the DJI Phantom 3 Professional. The experiments have shown that the calibration parameters tend to be unstable for small sensors. Furthermore, the dense matching of images remains a particular problem to address in a close range photogrammetry project, more so in the presence of noise on the images. Data management in cases where the number of images is high is also very important. The UAV is nevertheless a suitable solution for the surveying and recording of historical buildings because it is able to take images from points of view which are normally inaccessible to classical terrestrial techniques.

  10. Combined echo offset (Dixon) and line volume chemical shift imaging as a clinical imaging protocol

    International Nuclear Information System (INIS)

    Listerud, J.; Chan, T.; Lenkinski, R.E.; Kressel, H.Y.; Chao, P.W.

    1989-01-01

    The authors have studied the sensitivity and specificity of the line-volume chemical-shift imaging (CSI) method as compared with the Dixon method they have recently implemented on a Signa, which supports a variety of options. Potential sources or error for the Dixon method include line broadening due to susceptibility, field inhomogeneity, and errors form olefinic resonances associated with fat, which behave like water in the Dixon regime. The authors investigate whether a combined Dixon/line-volume CSI method could be used to improve the placement of the line volume and to provide higher sensitivity and specificity than does the Dixon method alone

  11. Short dynamic FDG-PET imaging protocol for patients with lung cancer

    International Nuclear Information System (INIS)

    Torizuka, Tatsuo; Nobezawa, Shuji; Kanno, Toshihiko; Ouchi, Yasuomi; Momiki, Shigeru; Kasamatsu, Norio; Yoshikawa, Etsuji; Futatsubashi, Masami; Okada, Hiroyuki

    2000-01-01

    This positron emission tomography (PET) study was designed to compare 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) kinetic parameters of tumours derived from imaging frames of 0-60 min post FDG injection with those derived from shorter imaging frames of 0-30 min. Dynamic FDG-PET scans were performed on 20 patients with primary lung cancers for 1 h after intravenous injection of FDG. Images were reconstructed with attenuation correction using transmission images obtained with a germanium-68 ring source immediately before FDG injection. A region of interest (ROI) was placed on the plane of the maximal tumour FDG uptake. Arterial input function was estimated from an ROI defined in the left atrium. Based on the standard three-compartment metabolic model, we calculated the rate constants (K 1 -k 3 ) and influx constant K i = K 1 k 3 /(k 2 +k 3 ) using the imaging frames for 60 min and 30 min post FDG injection. The standardized uptake value (SUV) of tumour was measured using the imaging frame of 50-60 min post injection. High correlations were observed between kinetic parameters (K 1 , k 2 , k 3 and K i ) derived from imaging frames of 0-60 min and 0-30 min [0.231±0.114 vs 0.260±0.174 (r=0.958), 1.149±1.038 vs 1.565±2.027 (r=0.968), 0.259±0.154 vs 0.311±0.194 (r=0.886) and 0.044±0.022 vs 0.048±0.023 (r=0.961), respectively, P i showed an excellent agreement between the two methods (y=-0.0041+0.09831x). Mean SUV of the lung cancers was 6.58±2.85. It is concluded that the briefer 30-min acquisition may yield essentially the same results as the standard 60-min imaging protocol, thus offering a time saving in dynamic PET studies in which the model parameters are desired. (orig.)

  12. Behavioral effects of acclimatization to restraint protocol used for awake animal imaging.

    Science.gov (United States)

    Reed, Michael D; Pira, Ashley S; Febo, Marcelo

    2013-07-15

    Functional MRI in awake rats involves acclimatization to restraint to minimize motion. We designed a study to examine the effects of an acclimatization protocol (5 days of restraint, 60 min per day) on the emission of 22-kHz ultrasonic vocalizations and performance in a forced swim test (FST). Our results showed that USV calls are reduced significantly by days 3, 4 and 5 of acclimatization. Although the rats showed less climbing activity (and more immobility) in FST on day 5 compared to the 1st day of restraint acclimatization, the difference was not detected once the animals were given a 2-week hiatus. Overall, we showed that animals adapt to the restraint over a five-day period; however, restraint may introduce confounding behavioral outcomes that may hinder the interpretation of results derived from awake rat imaging. The present data warrants further testing of the effects of MRI restraint on behavior. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Novel structural features drive DNA binding properties of Cmr, a CRP family protein in TB complex mycobacteria.

    Science.gov (United States)

    Ranganathan, Sridevi; Cheung, Jonah; Cassidy, Michael; Ginter, Christopher; Pata, Janice D; McDonough, Kathleen A

    2018-01-09

    Mycobacterium tuberculosis (Mtb) encodes two CRP/FNR family transcription factors (TF) that contribute to virulence, Cmr (Rv1675c) and CRPMt (Rv3676). Prior studies identified distinct chromosomal binding profiles for each TF despite their recognizing overlapping DNA motifs. The present study shows that Cmr binding specificity is determined by discriminator nucleotides at motif positions 4 and 13. X-ray crystallography and targeted mutational analyses identified an arginine-rich loop that expands Cmr's DNA interactions beyond the classical helix-turn-helix contacts common to all CRP/FNR family members and facilitates binding to imperfect DNA sequences. Cmr binding to DNA results in a pronounced asymmetric bending of the DNA and its high level of cooperativity is consistent with DNA-facilitated dimerization. A unique N-terminal extension inserts between the DNA binding and dimerization domains, partially occluding the site where the canonical cAMP binding pocket is found. However, an unstructured region of this N-terminus may help modulate Cmr activity in response to cellular signals. Cmr's multiple levels of DNA interaction likely enhance its ability to integrate diverse gene regulatory signals, while its novel structural features establish Cmr as an atypical CRP/FNR family member. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  14. Coronary artery anomalies. Diagnosis and classification based on cardiac CT and MRI (CMR) - from ALCAPA to anomalies of termination

    International Nuclear Information System (INIS)

    Heermann, Philipp; Heindel, Walter; Schuelke, Christoph

    2017-01-01

    Coronary artery anomalies encompass a clinically and anatomically variable spectrum including physiological variants and pathophysiologically relevant anomalies. The majority of the variants has no hemodynamic relevance and is often detected accidentally. The recognition of the rare and relevant anomalies that cause either relevant shunt volumes leading to myocardial ischemia or ventricular tachyarrhythmias with the risk of sudden cardiac death is of major importance. This review is based on a literature search in PubMed conducted using the key words ''coronary artery'' and/or ''anomaly'' and/or ''anomalous origin'' and/or ''myocardial bridging'' and/or ''coronary artery fistula'' and/or ''Bland-White-Garland'' and/or ''ALCAPA''. Coronary artery anomalies can be anatomically subdivided into anomalies of origin, course and termination. The method of choice for anatomical imaging is ECG-triggered or gated multislice CT (MSCT) that provides high spatial resolution and the capability of multiplanar reconstructions. It facilitates the delineation of the precise course of all three coronary arteries and thus allows for correct classification in the anatomical classification system of coronary artery anomalies. The strengths of cardiac magnetic resonance imaging (CMR) are the evaluation of cardiac morphology, myocardial tissue properties and myocardial function. Basic methods are the analysis of myocardial contraction and perfusion with and without pharmacologic stress. Furthermore, potential shunt volumes could be quantified by phase contrast imaging or volumetry.

  15. SU-F-R-06: Traumatic Brachial Plexus Injury Imaging, Developing a Coherent Clinical Protocol From Literature Review Through Practice

    International Nuclear Information System (INIS)

    Wu, D; France, E; Lambert, J; Hinkle, J

    2016-01-01

    Purpose: Medical Physics teams can now play a critical role to help plan and provide studied approaches for traumatic brachial plexus MR imaging (tbpMRI). This is especially important for coordination with uncommon applications, since it is challenging to select the right modality, parameters, and train technologists on the essential components. For this work, we started with a review of the medical literature, performed crossover/volunteer studies to bring tbpMRI to practice with greater image QC and protocol management. Methods: To the best of our knowledge, we reviewed the known searchable domain for tbpMRI. We found 69 total articles since 2000. Articles were evaluated with our published protocol for literature management (LIMES3). Two physicists and two radiologists condensed the information from all articles into a knowledgebase. Results: The initial literature demonstrated great heterogeneity, which was a sign that this area needed greater consistency. Despite inconsistency and imprecision, we extracted the most relevant targets using our long-term experience with protocol development in MSK. We ran volunteers on six different magnets of various field strengths with multiple receiver coils, and rebuilt a coherent protocol for tbpMRI. Our radiologists rated LIMES3 work as superior. We have received referrals from the ER and have conducted four patient evaluations. Conclusion: Traumatic brachial plexus MRI has great possible benefits for patients. This work supports the complexity of tbpMRI scanning. As this is rarely performed, it requires a more diligent protocol workflow, coordination of caregivers, and education within multiple clinical departments. Choosing the correct imaging exam can be critical, as patients can have significant neuropathy and/or paralysis. The LIMES3 protocol is well liked at our institution, and forms the cornerstone of understanding for our work. Our literature management led to a better clinical protocol creation despite the diffuse

  16. SU-F-R-06: Traumatic Brachial Plexus Injury Imaging, Developing a Coherent Clinical Protocol From Literature Review Through Practice

    Energy Technology Data Exchange (ETDEWEB)

    Wu, D; France, E; Lambert, J; Hinkle, J [The University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2016-06-15

    Purpose: Medical Physics teams can now play a critical role to help plan and provide studied approaches for traumatic brachial plexus MR imaging (tbpMRI). This is especially important for coordination with uncommon applications, since it is challenging to select the right modality, parameters, and train technologists on the essential components. For this work, we started with a review of the medical literature, performed crossover/volunteer studies to bring tbpMRI to practice with greater image QC and protocol management. Methods: To the best of our knowledge, we reviewed the known searchable domain for tbpMRI. We found 69 total articles since 2000. Articles were evaluated with our published protocol for literature management (LIMES3). Two physicists and two radiologists condensed the information from all articles into a knowledgebase. Results: The initial literature demonstrated great heterogeneity, which was a sign that this area needed greater consistency. Despite inconsistency and imprecision, we extracted the most relevant targets using our long-term experience with protocol development in MSK. We ran volunteers on six different magnets of various field strengths with multiple receiver coils, and rebuilt a coherent protocol for tbpMRI. Our radiologists rated LIMES3 work as superior. We have received referrals from the ER and have conducted four patient evaluations. Conclusion: Traumatic brachial plexus MRI has great possible benefits for patients. This work supports the complexity of tbpMRI scanning. As this is rarely performed, it requires a more diligent protocol workflow, coordination of caregivers, and education within multiple clinical departments. Choosing the correct imaging exam can be critical, as patients can have significant neuropathy and/or paralysis. The LIMES3 protocol is well liked at our institution, and forms the cornerstone of understanding for our work. Our literature management led to a better clinical protocol creation despite the diffuse

  17. Protocol images for staging of gastric cancer in radiology Hospital San Vicente de Paul

    International Nuclear Information System (INIS)

    Jarquin Salvatierra, Estibaliz

    2010-01-01

    The realization of a protocol for the evaluation of imaging in the radiology service of Hospital San Vicente de Paul in the province of Heredia is considered a useful tool that allows a clear and simple communication with the rest of the interdisciplinary team that serves patients with gastric cancer. The adequate management of this disease is important for an assessment and standardized reporting of images to facilitate preoperative planning; because the number of diagnostic studies that should be performed for the detection once obtained the histological diagnosis to establish the staging. Prior knowledge of stage according to TNM (Tumor/Nodes/Metastasis) classification is essential. The initial assessment for radiological detection of gastric cancer was performed with gastroduodenal series with double contrast medium and fluoroscopic control. The establishment of a study effects required for routine is important and avoid underdiagnosis.The new Hospital San Vicente de Paul will have the tomographic assessment and trans abdominal ultrasound (USTA) essential to assess the presence of metastasis to peritoneum and solid organs, in addition to the adenomegaly suggesting neoplastic infiltration. (author) [es

  18. Multi-vendor, multicentre comparison of contrast-enhanced SSFP and T2-STIR CMR for determining myocardium at risk in ST-elevation myocardial infarction

    Science.gov (United States)

    Nordlund, David; Klug, Gert; Heiberg, Einar; Koul, Sasha; Larsen, Terje H.; Hoffmann, Pavel; Metzler, Bernhard; Erlinge, David; Atar, Dan; Aletras, Anthony H.; Carlsson, Marcus; Engblom, Henrik; Arheden, Håkan

    2016-01-01

    Aims Myocardial salvage, determined by cardiac magnetic resonance imaging (CMR), is used as end point in cardioprotection trials. To calculate myocardial salvage, infarct size is related to myocardium at risk (MaR), which can be assessed by T2-short tau inversion recovery (T2-STIR) and contrast-enhanced steady-state free precession magnetic resonance imaging (CE-SSFP). We aimed to determine how T2-STIR and CE-SSFP perform in determining MaR when applied in multicentre, multi-vendor settings. Methods and results A total of 215 patients from 17 centres were included after percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction. CMR was performed within 1–8 days. These patients participated in the MITOCARE or CHILL-MI cardioprotection trials. Additionally, 8 patients from a previous study, imaged 1 day post-CMR, were included. Late gadolinium enhancement, T2-STIR, and CE-SSFP images were acquired on 1.5T MR scanners (Philips, Siemens, or GE). In 65% of the patients, T2-STIR was of diagnostic quality compared with 97% for CE-SSFP. In diagnostic quality images, there was no difference in MaR by T2-STIR and CE-SSFP (bias: 0.02 ± 6%, P = 0.96, r2 = 0.71, P < 0.001), or between treatment and control arms. No change in size or quality of MaR nor ability to identify culprit artery was seen over the first week after the acute event (P = 0.44). Conclusion In diagnostic quality images, T2-STIR and CE-SSFP provide similar estimates of MaR, were constant over the first week, and were not affected by treatment. CE-SSFP had a higher degree of diagnostic quality images compared with T2 imaging for sequences from two out of three vendors. Therefore, CE-SSFP is currently more suitable for implementation in multicentre, multi-vendor clinical trials. PMID:27002140

  19. Left atrial volume assessment in atrial fibrillation using multimodality imaging: a comparison of echocardiography, invasive three-dimensional CARTO and cardiac magnetic resonance imaging.

    Science.gov (United States)

    Rabbat, Mark G; Wilber, David; Thomas, Kevin; Malick, Owais; Bashir, Atif; Agrawal, Anoop; Biswas, Santanu; Sanagala, Thriveni; Syed, Mushabbar A

    2015-06-01

    Left atrial size in atrial fibrillation is a strong predictor of successful ablation and cardiovascular events. Cardiac magnetic resonance multislice method (CMR-MSM) is the current gold standard for left atrial volume (LAV) assessment but is time consuming. We investigated whether LAV with more rapid area-length method by echocardiography (Echo-AL) or cardiac magnetic resonance (CMR-AL) and invasive measurement by 3D-CARTO mapping during ablation correlate with the CMR-MSM. We studied 250 consecutive patients prior to atrial fibrillation ablation. CMR images were acquired on 3T scanner to measure LAV by MSM and biplane area-length method. Standard echocardiography views were used to calculate LAV by biplane area-length method. LAV during ablation was measured by 3D-CARTO mapping. LAV was compared using intra-class correlation (ICC), Pearson's correlation and Bland-Altman plots. CMR-MSM was used as the reference standard. Mean LAV using CMR-MSM was 112.7 ± 36.7 ml. CMR-AL method overestimated LAV by 13.3 ± 21.8 ml (11.2%, p atrial fibrillation. CMR-AL and 3D-CARTO correlated and agreed well with CMR-MSM (r = 0.87 and 0.74, ICC = 0.80 and 0.77 respectively). However, Echo-AL had poor correlation and agreement with CMR-MSM (r = 0.66 and ICC = 0.48). Bland-Altman plots confirmed these findings. CMR-AL method may be used as an alternative to CMR-MSM, as it is non-invasive, rapid, and correlates well with CMR-MSM. LAV by different modalities should not be used interchangeably.

  20. Head CT: Image quality improvement with ASIR-V using a reduced radiation dose protocol for children

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Gi [Ajou University School of Medicine, Ajou University Medical Center, Department of Radiology, Yeongtong-gu, Suwon (Korea, Republic of); Lee, Ho-Joon; Lee, Seung-Koo; Kim, Myung-Joon [Severance Hospital, Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Seodaemun-gu, Seoul (Korea, Republic of); Kim, Hyun Ji [Ajou University School of Medicine, Office of Biostatistics, Department of Humanities and Social Medicine, Yeongtong-gu, Suwon (Korea, Republic of)

    2017-09-15

    To investigate the quality of images reconstructed with adaptive statistical iterative reconstruction V (ASIR-V), using pediatric head CT protocols. A phantom was scanned at decreasing 20% mA intervals using our standard pediatric head CT protocols. Each study was then reconstructed at 10% ASIR-V intervals. After the phantom study, we reduced mA by 10% in the protocol for <3-year-old patients and applied 30% ASIR-V and by 30% in the protocol for 3- to 15-year-old patients and applied 40% ASIR-V. Increasing the percentage of ASIR-V resulted in lower noise and higher contrast-to-noise ratio (CNR) and preserved spatial resolution in the phantom study. Compared to a conventional-protocol, reduced-dose protocol with ASIR-V achieved 12.8% to 34.0% of dose reduction and showed images of lower noise (9.22 vs. 10.73, P = 0.043) and higher CNR in different levels (centrum semiovale, 2.14 vs. 1.52, P = 0.003; basal ganglia, 1.46 vs. 1.07, P = 0.001; and cerebellum, 2.18 vs. 1.33, P < 0.001). Qualitative analysis showed higher gray-white matter differentiation and sharpness and preserved overall diagnostic quality in the images with ASIR-V. Use of ASIR-V allowed a 12.8% to 34.0% dose reduction in each age group with potential to improve image quality. (orig.)

  1. Head CT: Image quality improvement with ASIR-V using a reduced radiation dose protocol for children.

    Science.gov (United States)

    Kim, Hyun Gi; Lee, Ho-Joon; Lee, Seung-Koo; Kim, Hyun Ji; Kim, Myung-Joon

    2017-09-01

    To investigate the quality of images reconstructed with adaptive statistical iterative reconstruction V (ASIR-V), using pediatric head CT protocols. A phantom was scanned at decreasing 20% mA intervals using our standard pediatric head CT protocols. Each study was then reconstructed at 10% ASIR-V intervals. After the phantom study, we reduced mA by 10% in the protocol for ASIR-V and by 30% in the protocol for 3- to 15-year-old patients and applied 40% ASIR-V. Increasing the percentage of ASIR-V resulted in lower noise and higher contrast-to-noise ratio (CNR) and preserved spatial resolution in the phantom study. Compared to a conventional-protocol, reduced-dose protocol with ASIR-V achieved 12.8% to 34.0% of dose reduction and showed images of lower noise (9.22 vs. 10.73, P = 0.043) and higher CNR in different levels (centrum semiovale, 2.14 vs. 1.52, P = 0.003; basal ganglia, 1.46 vs. 1.07, P = 0.001; and cerebellum, 2.18 vs. 1.33, P ASIR-V. Use of ASIR-V allowed a 12.8% to 34.0% dose reduction in each age group with potential to improve image quality. • It is possible to reduce radiation dose and improve image quality with ASIR-V. • We improved noise and CNR and decreased radiation dose. • Sharpness improved with ASIR-V. • Total radiation dose was decreased by 12.8% to 34.0%.

  2. Head CT: Image quality improvement with ASIR-V using a reduced radiation dose protocol for children

    International Nuclear Information System (INIS)

    Kim, Hyun Gi; Lee, Ho-Joon; Lee, Seung-Koo; Kim, Myung-Joon; Kim, Hyun Ji

    2017-01-01

    To investigate the quality of images reconstructed with adaptive statistical iterative reconstruction V (ASIR-V), using pediatric head CT protocols. A phantom was scanned at decreasing 20% mA intervals using our standard pediatric head CT protocols. Each study was then reconstructed at 10% ASIR-V intervals. After the phantom study, we reduced mA by 10% in the protocol for <3-year-old patients and applied 30% ASIR-V and by 30% in the protocol for 3- to 15-year-old patients and applied 40% ASIR-V. Increasing the percentage of ASIR-V resulted in lower noise and higher contrast-to-noise ratio (CNR) and preserved spatial resolution in the phantom study. Compared to a conventional-protocol, reduced-dose protocol with ASIR-V achieved 12.8% to 34.0% of dose reduction and showed images of lower noise (9.22 vs. 10.73, P = 0.043) and higher CNR in different levels (centrum semiovale, 2.14 vs. 1.52, P = 0.003; basal ganglia, 1.46 vs. 1.07, P = 0.001; and cerebellum, 2.18 vs. 1.33, P < 0.001). Qualitative analysis showed higher gray-white matter differentiation and sharpness and preserved overall diagnostic quality in the images with ASIR-V. Use of ASIR-V allowed a 12.8% to 34.0% dose reduction in each age group with potential to improve image quality. (orig.)

  3. Interoperative fundus image and report sharing in compliance with integrating the healthcare enterprise conformance and web access todigital imaging and communication in medicinepersistent object protocol

    Directory of Open Access Journals (Sweden)

    Hui-Qun Wu

    2013-12-01

    Full Text Available AIM:To address issues in interoperability between different fundus image systems, we proposed a web eye-picture archiving and communication system (PACS framework in conformance with digital imaging and communication in medicine (DICOM and health level 7 (HL7 protocol to realize fundus images and reports sharing and communication through internet.METHODS: Firstly, a telemedicine-based eye care work flow was established based on integrating the healthcare enterprise (IHE Eye Care technical framework. Then, a browser/server architecture eye-PACS system was established in conformance with the web access to DICOM persistent object (WADO protocol, which contains three tiers.RESULTS:In any client system installed with web browser, clinicians could log in the eye-PACS to observe fundus images and reports. Multipurpose internet mail extensions (MIME type of a structured report is saved as pdf/html with reference link to relevant fundus image using the WADO syntax could provide enough information for clinicians. Some functions provided by open-source Oviyam could be used to query, zoom, move, measure, view DICOM fundus images.CONCLUSION:Such web eye-PACS in compliance to WADO protocol could be used to store and communicate fundus images and reports, therefore is of great significance for teleophthalmology.

  4. Interoperative fundus image and report sharing in compliance with integrating the healthcare enterprise conformance and web access to digital imaging and communication in medicine persistent object protocol.

    Science.gov (United States)

    Wu, Hui-Qun; Lv, Zheng-Min; Geng, Xing-Yun; Jiang, Kui; Tang, Le-Min; Zhou, Guo-Min; Dong, Jian-Cheng

    2013-01-01

    To address issues in interoperability between different fundus image systems, we proposed a web eye-picture archiving and communication system (PACS) framework in conformance with digital imaging and communication in medicine (DICOM) and health level 7 (HL7) protocol to realize fundus images and reports sharing and communication through internet. Firstly, a telemedicine-based eye care work flow was established based on integrating the healthcare enterprise (IHE) Eye Care technical framework. Then, a browser/server architecture eye-PACS system was established in conformance with the web access to DICOM persistent object (WADO) protocol, which contains three tiers. In any client system installed with web browser, clinicians could log in the eye-PACS to observe fundus images and reports. Multipurpose internet mail extensions (MIME) type of a structured report is saved as pdf/html with reference link to relevant fundus image using the WADO syntax could provide enough information for clinicians. Some functions provided by open-source Oviyam could be used to query, zoom, move, measure, view DICOM fundus images. Such web eye-PACS in compliance to WADO protocol could be used to store and communicate fundus images and reports, therefore is of great significance for teleophthalmology.

  5. Biplane interventional pediatric system with cone‐beam CT: dose and image quality characterization for the default protocols

    Science.gov (United States)

    Vañó, Eliseo; Alejo, Luis; Ubeda, Carlos; Gutiérrez‐Larraya, Federico; Garayoa, Julia

    2016-01-01

    The aim of this study was to assess image quality and radiation dose of a biplane angiographic system with cone‐beam CT (CBCT) capability tuned for pediatric cardiac procedures. The results of this study can be used to explore dose reduction techniques. For pulsed fluoroscopy and cine modes, polymethyl methacrylate phantoms of various thicknesses and a Leeds TOR 18‐FG test object were employed. Various fields of view (FOV) were selected. For CBCT, the study employed head and body dose phantoms, Catphan 504, and an anthropomorphic cardiology phantom. The study also compared two 3D rotational angiography protocols. The entrance surface air kerma per frame increases by a factor of 3–12 when comparing cine and fluoroscopy frames. The biggest difference in the signal‐to‐noise ratio between fluoroscopy and cine modes occurs at FOV 32 cm because fluoroscopy is acquired at a 1440×1440 pixel matrix size and in unbinned mode, whereas cine is acquired at 720×720 pixels and in binned mode. The high‐contrast spatial resolution of cine is better than that of fluoroscopy, except for FOV 32 cm, because fluoroscopy mode with 32 cm FOV is unbinned. Acquiring CBCT series with a 16 cm head phantom using the standard dose protocol results in a threefold dose increase compared with the low‐dose protocol. Although the amount of noise present in the images acquired with the low‐dose protocol is much higher than that obtained with the standard mode, the images present better spatial resolution. A 1 mm diameter rod with 250 Hounsfield units can be distinguished in reconstructed images with an 8 mm slice width. Pediatric‐specific protocols provide lower doses while maintaining sufficient image quality. The system offers a novel 3D imaging mode. The acquisition of CBCT images results in increased doses administered to the patients, but also provides further diagnostic information contained in the volumetric images. The assessed CBCT protocols provide images that are noisy

  6. Biplane interventional pediatric system with cone-beam CT: dose and image quality characterization for the default protocols.

    Science.gov (United States)

    Corredoira, Eva; Vañó, Eliseo; Alejo, Luis; Ubeda, Carlos; Gutiérrez-Larraya, Federico; Garayoa, Julia

    2016-07-08

    The aim of this study was to assess image quality and radiation dose of a biplane angiographic system with cone-beam CT (CBCT) capability tuned for pediatric cardiac procedures. The results of this study can be used to explore dose reduction techniques. For pulsed fluoroscopy and cine modes, polymethyl methacrylate phantoms of various thicknesses and a Leeds TOR 18-FG test object were employed. Various fields of view (FOV) were selected. For CBCT, the study employed head and body dose phantoms, Catphan 504, and an anthropomorphic cardiology phantom. The study also compared two 3D rotational angiography protocols. The entrance surface air kerma per frame increases by a factor of 3-12 when comparing cine and fluoroscopy frames. The biggest difference in the signal-to- noise ratio between fluoroscopy and cine modes occurs at FOV 32 cm because fluoroscopy is acquired at a 1440 × 1440 pixel matrix size and in unbinned mode, whereas cine is acquired at 720 × 720 pixels and in binned mode. The high-contrast spatial resolution of cine is better than that of fluoroscopy, except for FOV 32 cm, because fluoroscopy mode with 32 cm FOV is unbinned. Acquiring CBCT series with a 16 cm head phantom using the standard dose protocol results in a threefold dose increase compared with the low-dose protocol. Although the amount of noise present in the images acquired with the low-dose protocol is much higher than that obtained with the standard mode, the images present better spatial resolution. A 1 mm diameter rod with 250 Hounsfield units can be distinguished in reconstructed images with an 8 mm slice width. Pediatric-specific protocols provide lower doses while maintaining sufficient image quality. The system offers a novel 3D imaging mode. The acquisition of CBCT images results in increased doses administered to the patients, but also provides further diagnostic information contained in the volumetric images. The assessed CBCT protocols provide images that are noisy, but with

  7. Protocol and quality assurance for carotid imaging in 100,000 participants of UK Biobank: development and assessment.

    Science.gov (United States)

    Coffey, Sean; Lewandowski, Adam J; Garratt, Steve; Meijer, Rudy; Lynum, Steven; Bedi, Ram; Paterson, James; Yaqub, Mohammad; Noble, J Alison; Neubauer, Stefan; Petersen, Steffen E; Allen, Naomi; Sudlow, Cathie; Collins, Rory; Matthews, Paul M; Leeson, Paul

    2017-11-01

    Background Ultrasound imaging is able to quantify carotid arterial wall structure for the assessment of cerebral and cardiovascular disease risks. We describe a protocol and quality assurance process to enable carotid imaging at large scale that has been developed for the UK Biobank Imaging Enhancement Study of 100,000 individuals. Design An imaging protocol was developed to allow measurement of carotid intima-media thickness from the far wall of both common carotid arteries. Six quality assurance criteria were defined and a web-based interface (Intelligent Ultrasound) was developed to facilitate rapid assessment of images against each criterion. Results and conclusions Excellent inter and intra-observer agreements were obtained for image quality evaluations on a test dataset from 100 individuals. The image quality criteria then were applied in the UK Biobank Imaging Enhancement Study. Data from 2560 participants were evaluated. Feedback of results to the imaging team led to improvement in quality assurance, with quality assurance failures falling from 16.2% in the first two-month period examined to 6.4% in the last. Eighty per cent had all carotid intima-media thickness images graded as of acceptable quality, with at least one image acceptable for 98% of participants. Carotid intima-media thickness measures showed expected associations with increasing age and gender. Carotid imaging can be performed consistently, with semi-automated quality assurance of all scans, in a limited timeframe within a large scale multimodality imaging assessment. Routine feedback of quality control metrics to operators can improve the quality of the data collection.

  8. Optimization on the dose versus noise in the image on protocols for computed tomography of pediatric head

    International Nuclear Information System (INIS)

    Saint'Yves, Thalis L.A.; Travassos, Paulo Cesar B.; Goncalves, Elicardo A.S.; Mecca A, Fernando; Silveira, Thiago B.

    2010-01-01

    This article aims to establish protocols optimized for computed tomography of pediatric skull, to the Picker Q2000 tomography of the Instituto Nacional de Cancer, through the analysis of dose x noise on the image with the variation of values of mAs and kVp. We used a water phantom to measure the noise, a pencil type ionization chamber to measure the dose in the air and the Alderson Randon phantom for check the quality of the image. We found values of mAs and kVp that reduce the skin dose of the original protocol used in 35.9%, maintaining the same image quality at a safe diagnosis. (author)

  9. Relationships of clinical protocols and reconstruction kernels with image quality and radiation dose in a 128-slice CT scanner: Study with an anthropomorphic and water phantom

    International Nuclear Information System (INIS)

    Paul, Jijo; Krauss, B.; Banckwitz, R.; Maentele, W.; Bauer, R.W.; Vogl, T.J.

    2012-01-01

    Research highlights: ► Clinical protocol, reconstruction kernel, reconstructed slice thickness, phantom diameter or the density of material it contains directly affects the image quality of DSCT. ► Dual energy protocol shows the lowest DLP compared to all other protocols examined. ► Dual-energy fused images show excellent image quality and the noise is same as that of single- or high-pitch mode protocol images. ► Advanced CT technology improves image quality and considerably reduce radiation dose. ► An important finding is the comparatively higher DLP of the dual-source high-pitch protocol compared to other single- or dual-energy protocols. - Abstract: Purpose: The aim of this study was to explore the relationship of scanning parameters (clinical protocols), reconstruction kernels and slice thickness with image quality and radiation dose in a DSCT. Materials and methods: The chest of an anthropomorphic phantom was scanned on a DSCT scanner (Siemens Somatom Definition flash) using different clinical protocols, including single- and dual-energy modes. Four scan protocols were investigated: 1) single-source 120 kV, 110 mA s, 2) single-source 100 kV, 180 mA s, 3) high-pitch 120 kV, 130 mA s and 4) dual-energy with 100/Sn140 kV, eff.mA s 89, 76. The automatic exposure control was switched off for all the scans and the CTDIvol selected was in between 7.12 and 7.37 mGy. The raw data were reconstructed using the reconstruction kernels B31f, B80f and B70f, and slice thicknesses were 1.0 mm and 5.0 mm. Finally, the same parameters and procedures were used for the scanning of water phantom. Friedman test and Wilcoxon-Matched-Pair test were used for statistical analysis. Results: The DLP based on the given CTDIvol values showed significantly lower exposure for protocol 4, when compared to protocol 1 (percent difference 5.18%), protocol 2 (percent diff. 4.51%), and protocol 3 (percent diff. 8.81%). The highest change in Hounsfield Units was observed with dual

  10. Making MR Imaging Child's Play - Pediatric Neuroimaging Protocol, Guidelines and Procedure

    Science.gov (United States)

    Raschle, Nora M.; Lee, Michelle; Buechler, Roman; Christodoulou, Joanna A.; Chang, Maria; Vakil, Monica; Stering, Patrice L.; Gaab, Nadine

    2009-01-01

    's compliance during MR imaging sessions 19,20. In the current video report, we present a pediatric neuroimaging protocol with guidelines and procedures that have proven to be successful to date in young children. PMID:19684560

  11. Introduction of a standardized multimodality image protocol for navigation-guided surgery of suspected low-grade gliomas.

    Science.gov (United States)

    Mert, Aygül; Kiesel, Barbara; Wöhrer, Adelheid; Martínez-Moreno, Mauricio; Minchev, Georgi; Furtner, Julia; Knosp, Engelbert; Wolfsberger, Stefan; Widhalm, Georg

    2015-01-01

    OBJECT Surgery of suspected low-grade gliomas (LGGs) poses a special challenge for neurosurgeons due to their diffusely infiltrative growth and histopathological heterogeneity. Consequently, neuronavigation with multimodality imaging data, such as structural and metabolic data, fiber tracking, and 3D brain visualization, has been proposed to optimize surgery. However, currently no standardized protocol has been established for multimodality imaging data in modern glioma surgery. The aim of this study was therefore to define a specific protocol for multimodality imaging and navigation for suspected LGG. METHODS Fifty-one patients who underwent surgery for a diffusely infiltrating glioma with nonsignificant contrast enhancement on MRI and available multimodality imaging data were included. In the first 40 patients with glioma, the authors retrospectively reviewed the imaging data, including structural MRI (contrast-enhanced T1-weighted, T2-weighted, and FLAIR sequences), metabolic images derived from PET, or MR spectroscopy chemical shift imaging, fiber tracking, and 3D brain surface/vessel visualization, to define standardized image settings and specific indications for each imaging modality. The feasibility and surgical relevance of this new protocol was subsequently prospectively investigated during surgery with the assistance of an advanced electromagnetic navigation system in the remaining 11 patients. Furthermore, specific surgical outcome parameters, including the extent of resection, histological analysis of the metabolic hotspot, presence of a new postoperative neurological deficit, and intraoperative accuracy of 3D brain visualization models, were assessed in each of these patients. RESULTS After reviewing these first 40 cases of glioma, the authors defined a specific protocol with standardized image settings and specific indications that allows for optimal and simultaneous visualization of structural and metabolic data, fiber tracking, and 3D brain

  12. Practical protocols for fast histopathology by Fourier transform infrared spectroscopic imaging

    Science.gov (United States)

    Keith, Frances N.; Reddy, Rohith K.; Bhargava, Rohit

    2008-02-01

    Fourier transform infrared (FT-IR) spectroscopic imaging is an emerging technique that combines the molecular selectivity of spectroscopy with the spatial specificity of optical microscopy. We demonstrate a new concept in obtaining high fidelity data using commercial array detectors coupled to a microscope and Michelson interferometer. Next, we apply the developed technique to rapidly provide automated histopathologic information for breast cancer. Traditionally, disease diagnoses are based on optical examinations of stained tissue and involve a skilled recognition of morphological patterns of specific cell types (histopathology). Consequently, histopathologic determinations are a time consuming, subjective process with innate intra- and inter-operator variability. Utilizing endogenous molecular contrast inherent in vibrational spectra, specially designed tissue microarrays and pattern recognition of specific biochemical features, we report an integrated algorithm for automated classifications. The developed protocol is objective, statistically significant and, being compatible with current tissue processing procedures, holds potential for routine clinical diagnoses. We first demonstrate that the classification of tissue type (histology) can be accomplished in a manner that is robust and rigorous. Since data quality and classifier performance are linked, we quantify the relationship through our analysis model. Last, we demonstrate the application of the minimum noise fraction (MNF) transform to improve tissue segmentation.

  13. Characteristics of carotid atherosclerotic plaques of chronic lipid apheresis patients as assessed by In Vivo High-Resolution CMR - a comparative analysis

    Directory of Open Access Journals (Sweden)

    Grimm Jochen M

    2012-11-01

    Full Text Available Abstract Background Components of carotid atherosclerotic plaques can reliably be identified and quantified using high resolution in vivo 3-Tesla CMR. It is suspected that lipid apheresis therapy in addition to lowering serum lipid levels also has an influence on development and progression of atherosclerotic plaques. The purpose of this study was to evaluate the influence of chronic lipid apheresis (LA on the composition of atherosclerotic carotid plaques. Methods 32 arteries of 16 patients during chronic LA-therapy with carotid plaques and stenosis of 1–80% were matched according to degree of stenosis with 32 patients, who had recently suffered an ischemic stroke. Of these patients only the asymptomatic carotid artery was analyzed. All patients underwent black-blood 3 T CMR of the carotids using parallel imaging and dedicated surface coils. Cardiovascular risk factors were recorded. Morphology and composition of carotid plaques were evaluated. For statistical evaluation Fisher’s Exact and unpaired t-test were used. A p-value Results Patients in the LA-group were younger (63.5 vs. 73.9. years, p2, p Conclusion Results of this study suggest that, despite a severer risk profile for cardiovascular complications in LA-patients, chronic LA is associated with significantly lower lipid content in carotid plaques compared to plaques of patients without LA with similar degrees of stenosis, which is characteristic of clinically stable plaques.

  14. Development of an acquisition protocol and a segmentation algortihm for wounds of cutaneous Leishmaniasis in digital images

    Science.gov (United States)

    Diaz, Kristians; Castañeda, Benjamín; Miranda, César; Lavarello, Roberto; Llanos, Alejandro

    2010-03-01

    We developed a protocol for the acquisition of digital images and an algorithm for a color-based automatic segmentation of cutaneous lesions of Leishmaniasis. The protocol for image acquisition provides control over the working environment to manipulate brightness, lighting and undesirable shadows on the injury using indirect lighting. Also, this protocol was used to accurately calculate the area of the lesion expressed in mm2 even in curved surfaces by combining the information from two consecutive images. Different color spaces were analyzed and compared using ROC curves in order to determine the color layer with the highest contrast between the background and the wound. The proposed algorithm is composed of three stages: (1) Location of the wound determined by threshold and mathematical morphology techniques to the H layer of the HSV color space, (2) Determination of the boundaries of the wound by analyzing the color characteristics in the YIQ space based on masks (for the wound and the background) estimated from the first stage, and (3) Refinement of the calculations obtained on the previous stages by using the discrete dynamic contours algorithm. The segmented regions obtained with the algorithm were compared with manual segmentations made by a medical specialist. Broadly speaking, our results support that color provides useful information during segmentation and measurement of wounds of cutaneous Leishmaniasis. Results from ten images showed 99% specificity, 89% sensitivity, and 98% accuracy.

  15. Evaluation of contrast wash-in and peak enhancement in adenosine first pass perfusion CMR in patients post bypass surgery

    Directory of Open Access Journals (Sweden)

    Schnackenburg Bernhard

    2010-05-01

    Full Text Available Abstract Background Adenosine first pass perfusion cardiovascular magnetic resonance (CMR yields excellent results for the detection of significant coronary artery disease (CAD. In patients with coronary artery bypass grafts (CABG the kinetics of a contrast bolus may by altered only due to different distances through the bypass grafts compared to native vessels, thereby possibly imitating a perfusion defect. The aim of the study was to evaluate semiquantitative perfusion parameters in order to assess possible differences in epicardial contrast kinetics in areas supplied by native coronaries and CABG, both without significant stenosis. Methods Twenty patients with invasive exclusion of significant CAD (control group and 38 patients with CABG without angiographically significant (≥50% stenosis in unbypassed coronaries or grafts were retrospectively included in the study. They underwent adenosine first pass (0.05 mmol/kg Gd-DTPA perfusion (3 short axis views/heart beat and late gadolinium enhancement (LGE imaging 1 day before invasive coronary angiography. Areas perfused by native coronaries and/or the different bypasses were identified in X-ray angiography using the 16 segment model. In each of these areas upslope and maximal signal intensity (SImax relative to the left ventricular parameters, time to 50% maximal signal intensity (TSI50%max and time to maximal signal intensity (TSImax were calculated. Results In areas perfused by coronary arteries with bypasses compared to native coronaries relative upslope and relative SImax did not show a significant difference. TSI50%max and TSImax in native coronaries and bypasses were 7.2s ± 1.9s vs. 7.5s ± 1.9s (p max resulted in a significant (p Conclusion Adenosine perfusion CMR in patients post CABG may be associated with a short delay in contrast arrival. However, once the contrast is in the myocardium there is similar wash-in kinetics and peak enhancement. Therefore, since the delay is only short

  16. Cardiac T1 mapping in congenital heart disease: bolus vs. infusion protocols for measurements of myocardial extracellular volume fraction.

    Science.gov (United States)

    Al-Wakeel-Marquard, Nadya; Rastin, Sanaz; Muench, Frédéric; O H-Ici, Darach; Yilmaz, Sevim; Berger, Felix; Kuehne, Titus; Messroghli, Daniel R

    2017-12-01

    Myocardial extracellular volume fraction (ECV) reflecting diffuse myocardial fibrosis can be measured with T1 mapping cardiovascular magnetic resonance (CMR) before and after the application of a gadolinium-based extracellular contrast agent. The equilibrium between blood and myocardium contrast concentration required for ECV measurements can be obtained with a primed contrast infusion (equilibrium contrast-CMR). We hypothesized that equilibrium can also be achieved with a single contrast bolus to accurately measure diffuse myocardial fibrosis in patients with congenital heart disease (CHD). Healthy controls (n = 17; median age 24.0 years) and patients with CHD (n = 19; 25.0 years) were prospectively enrolled. Using modified Look-Locker inversion recovery T1 mapping before, 15 min after bolus injection, and during constant infusion of gadolinium-DOTA, T1 values were obtained for blood pool and myocardium of the left ventricle (LV), the interventricular septum (IVS), and the right ventricle (RV) in a single midventricular plane in short axis or in transverse orientation. ECV of LV, IVS and RV by bolus-only and bolus-infusion correlated significantly in CHD patients (r = 0.94, 0.95, and 0.74; p < 0.01, respectively) and healthy controls (r = 0.96, 0.89, and 0.64; p < 0.05, respectively). Bland-Altman plots revealed no significant bias between the techniques for any of the analyzed regions. ECV of LV and RV myocardium measured by bolus-only T1 mapping agrees well with bolus-infusion measurements in patients with CHD. The use of a bolus-only approach facilitates the integration of ECV measurements into existing CMR imaging protocols, allowing for assessment of diffuse myocardial fibrosis in CHD in clinical routine.

  17. A simple protocol for attenuating the auto-fluorescence of cyanobacteria for optimized fluorescence in situ hybridization (FISH) imaging.

    Science.gov (United States)

    Zeller, Perrine; Ploux, Olivier; Méjean, Annick

    2016-03-01

    Cyanobacteria contain pigments, which generate auto-fluorescence that interferes with fluorescence in situ hybridization (FISH) imaging of cyanobacteria. We describe simple chemical treatments using CuSO4 or H2O2 that significantly reduce the auto-fluorescence of Microcystis strains. These protocols were successfully applied in FISH experiments using 16S rRNA specific probes and filamentous cyanobacteria. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Augmented Quadruple-Phase Contrast Media Administration and Triphasic Scan Protocol Increases Image Quality at Reduced Radiation Dose During Computed Tomography Urography.

    Science.gov (United States)

    Saade, Charbel; Mohamad, May; Kerek, Racha; Hamieh, Nadine; Alsheikh Deeb, Ibrahim; El-Achkar, Bassam; Tamim, Hani; Abdul Razzak, Farah; Haddad, Maurice; Abi-Ghanem, Alain S; El-Merhi, Fadi

    The aim of this article was to investigate the opacification of the renal vasculature and the urogenital system during computed tomography urography by using a quadruple-phase contrast media in a triphasic scan protocol. A total of 200 patients with possible urinary tract abnormalities were equally divided between 2 protocols. Protocol A used the conventional single bolus and quadruple-phase scan protocol (pre, arterial, venous, and delayed), retrospectively. Protocol B included a quadruple-phase contrast media injection with a triphasic scan protocol (pre, arterial and combined venous, and delayed), prospectively. Each protocol used 100 mL contrast and saline at a flow rate of 4.5 mL. Attenuation profiles and contrast-to-noise ratio of the renal arteries, veins, and urogenital tract were measured. Effective radiation dose calculation, data analysis by independent sample t test, receiver operating characteristic, and visual grading characteristic analyses were performed. In arterial circulation, only the inferior interlobular arteries in both protocols showed a statistical significance (P contrast-to-noise ratio than protocol A (protocol B: 22.68 ± 13.72; protocol A: 14.75 ± 5.76; P contrast media and triphasic scan protocol usage increases the image quality at a reduced radiation dose.

  19. A tight binding model study of tunneling conductance spectra of spin and orbitally ordered CMR manganites

    Science.gov (United States)

    Panda, Saswati; Sahoo, D. D.; Rout, G. C.

    2018-04-01

    We report here a tight binding model for colossal magnetoresistive (CMR) manganites to study the pseudo gap (PG) behavior near Fermi level. In the Kubo-Ohata type DE model, we consider first and second nearest neighbor interactions for transverse spin fluctuations in core band and hopping integrals in conduction band, in the presence of static band Jahn-Teller distortion. The model Hamiltonian is solved using Zubarev's Green's function technique. The electron density of states (DOS) is found out from the Green's functions. We observe clear PG near Fermi level in the electron DOS.

  20. Pancreatic MRI for the surveillance of cystic neoplasms: Comparison of a short with a comprehensive imaging protocol

    Energy Technology Data Exchange (ETDEWEB)

    Pozzi-Mucelli, Raffaella Maria; Kartalis, Nikolaos [C1-46 Karolinska University Hospital, Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet and Department of Radiology, Stockholm (Sweden); Rinta-Kiikka, Irina [Tampere University Hospital, Department of Radiology, Medical Imaging Centre of Pirkanmaa Hospital District, Tampere (Finland); Wuensche, Katharina [St. Olavs University Hospital, Department of Radiology, Trondheim (Norway); Laukkarinen, Johanna [Tampere University Hospital, Department of Gastroenterology and Alimentary Tract Surgery, Tampere (Finland); Labori, Knut Joergen [Oslo University Hospital, Department of Hepato-Pancreato-Biliary Surgery, Oslo (Norway); Aanonsen, Kim [Oslo University Hospital, Department of Gastroenterology, Oslo (Norway); Verbeke, Caroline [Oslo University Hospital, Institute of Clinical Medicine, Oslo (Norway); Karolinska University Hospital, Department of Pathology, Stockholm (Sweden); Del Chiaro, Marco [Karolinska University Hospital, Division of Surgery, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet and Center for Digestive Diseases, Stockholm (Sweden)

    2017-01-15

    The study aims were to evaluate: (1) whether a short-protocol (SP) MRI for the surveillance of pancreatic cystic neoplasms (PCN) provides equivalent clinical information as a comprehensive-protocol (CP), and (2) the cost reduction from substituting CP with SP for patient surveillance. This retrospective study included 154 consecutive patients (median age: 66, 52 % men) with working-diagnosis of PCN and available contrast-enhanced MRI/MRCP. Three radiologists evaluated independently two imaging sets (SP/CP) per patient. The CP included: T2-weighted (HASTE/MRCP), DWI and T1-weighted (chemical-shift/pre-/post-contrast) images [acquisition time (AT) ∼ 35 min], whereas the SP included: T2-weighted HASTE and T1-weighted pre-contrast images (AT ∼ 8 min). Mean values of largest cyst/main pancreatic duct diameter (D{sub C}/D{sub MPD}) were compared. Agreement regarding presence/absence of cystic/MPD mural nodules (MN{sub C}/MN{sub MPD}), inter-observer agreement and cost differences between SP/CP were calculated. For D{sub C} and D{sub MPD}, mean values with SP/CP were 21.4/21.7 mm and 3.52/3.58 mm, while mean differences SP-CP were 0.3 mm (p = 0.02) and 0.06 mm (p = 0.12), respectively. For presence/absence of MN{sub C} and MN{sub MPD}, SP/CP coincided in 93 % and 98 % of cases, respectively. Inter-observer agreement was strong for SP/CP. SP-cost was 25 % of CP-cost. For the surveillance of PCN, short-protocol MRI provides information equivalent to the more time-consuming and costly comprehensive-protocol. (orig.)

  1. Pancreatic MRI for the surveillance of cystic neoplasms: Comparison of a short with a comprehensive imaging protocol

    International Nuclear Information System (INIS)

    Pozzi-Mucelli, Raffaella Maria; Kartalis, Nikolaos; Rinta-Kiikka, Irina; Wuensche, Katharina; Laukkarinen, Johanna; Labori, Knut Joergen; Aanonsen, Kim; Verbeke, Caroline; Del Chiaro, Marco

    2017-01-01

    The study aims were to evaluate: (1) whether a short-protocol (SP) MRI for the surveillance of pancreatic cystic neoplasms (PCN) provides equivalent clinical information as a comprehensive-protocol (CP), and (2) the cost reduction from substituting CP with SP for patient surveillance. This retrospective study included 154 consecutive patients (median age: 66, 52 % men) with working-diagnosis of PCN and available contrast-enhanced MRI/MRCP. Three radiologists evaluated independently two imaging sets (SP/CP) per patient. The CP included: T2-weighted (HASTE/MRCP), DWI and T1-weighted (chemical-shift/pre-/post-contrast) images [acquisition time (AT) ∼ 35 min], whereas the SP included: T2-weighted HASTE and T1-weighted pre-contrast images (AT ∼ 8 min). Mean values of largest cyst/main pancreatic duct diameter (D_C/D_M_P_D) were compared. Agreement regarding presence/absence of cystic/MPD mural nodules (MN_C/MN_M_P_D), inter-observer agreement and cost differences between SP/CP were calculated. For D_C and D_M_P_D, mean values with SP/CP were 21.4/21.7 mm and 3.52/3.58 mm, while mean differences SP-CP were 0.3 mm (p = 0.02) and 0.06 mm (p = 0.12), respectively. For presence/absence of MN_C and MN_M_P_D, SP/CP coincided in 93 % and 98 % of cases, respectively. Inter-observer agreement was strong for SP/CP. SP-cost was 25 % of CP-cost. For the surveillance of PCN, short-protocol MRI provides information equivalent to the more time-consuming and costly comprehensive-protocol. (orig.)

  2. Effect of eicosapentaenoic acid/docosahexaenoic acid on coronary high-intensity plaques detected with non-contrast T1-weighted imaging (the AQUAMARINE EPA/DHA study): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Nakao, Kazuhiro; Noguchi, Teruo; Asaumi, Yasuhide; Morita, Yoshiaki; Kanaya, Tomoaki; Fujino, Masashi; Hosoda, Hayato; Yoneda, Shuichi; Kawakami, Shoji; Nagai, Toshiyuki; Nishihira, Kensaku; Nakashima, Takahiro; Kumasaka, Reon; Arakawa, Tetsuo; Otsuka, Fumiyuki; Nakanishi, Michio; Kataoka, Yu; Tahara, Yoshio; Goto, Yoichi; Yamamoto, Haruko; Hamasaki, Toshimitsu; Yasuda, Satoshi

    2018-01-08

    Despite the success of HMG-CoA reductase inhibitor (statin) therapy in reducing atherosclerotic cardiovascular events, a residual risk for cardiovascular events in patients with coronary artery disease (CAD) remains. Long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are promising anti-atherosclerosis agents that might reduce the residual CAD risk. Non-contrast T1-weighted imaging (T1WI) with cardiac magnetic resonance (CMR) less invasively identifies high-risk coronary plaques as high-intensity signals. These high-intensity plaques (HIPs) are quantitatively assessed using the plaque-to-myocardium signal intensity ratio (PMR). Our goal is to assess the effect of EPA/DHA on coronary HIPs detected with T1WI in patients with CAD on statin treatment. This prospective, controlled, randomized, open-label study examines the effect of 12 months of EPA/DHA therapy and statin treatment on PMR of HIPs detected with CMR and computed tomography angiography (CTA) in patients with CAD. The primary endpoint is the change in PMR after EPA/DHA treatment. Secondary endpoints include changes in Hounsfield units, plaque volume, vessel area, and plaque area measured using CTA. Subjects are randomly assigned to either of three groups: the 2 g/day EPA/DHA group, the 4 g/day EPA/DHA group, or the no-treatment group. This trial will help assess whether EPA/DHA has an anti-atherosclerotic effect using PMR of HIPs detected by CMR. The trial outcomes will provide novel insights into the effect of EPA/DHA on high-risk coronary plaques and may provide new strategies for lowering the residual risk in patients with CAD on statin therapy. The University Hospital Medical Information Network (UMIN) Clinical Trials Registry, ID: UMIN000015316 . Registered on 2 October 2014.

  3. Contrast-enhanced CMR in patients after percutaneous closure of the left atrial appendage: A pilot study

    Directory of Open Access Journals (Sweden)

    Petersen Steffen E

    2011-07-01

    Full Text Available Abstract Background To evaluate the feasibility and value of first-pass contrast-enhanced dynamic and post-contrast 3D CMR in patients after transcatheter occlusion of left atrial appendage (LAA to identify incorrect placement and persistent leaks. Methods 7 patients with different occluder systems (n = 4 PLAATO; n = 2 Watchman; n = 1 ACP underwent 2 contrast-enhanced (Gd-DOTA CMR sequences (2D TrueFISP first-pass perfusion and 3D-TurboFLASH to assess localization, artifact size and potential leaks of the devices. Perfusion CMR was analyzed visually and semi-quantitatively to identify potential leaks. Results All occluders were positioned within the LAA. The ACP occluder presented the most extensive artifact size. Visual assessment revealed a residual perfusion of the LAA apex in 4 cases using first-pass perfusion and 3D-TurboFLASH indicating a suboptimal LAA occlusion. By assessing signal-to-time-curves the cases with a visually detected leak showed a 9-fold higher signal-peak in the LAA apex (567 ± 120% increase from baseline signal than those without a leak (61 ± 22%; p Conclusion This CMR pilot study provides valuable non-invasive information in patients after transcatheter occlusion of the LAA to identify correct placement and potential leaks. We recommend incorporating CMR in future clinical studies to evaluate new device types.

  4. Magnetic resonance imaging guided transatrial electrophysiological studies in swine using active catheter tracking - experience with 14 cases

    Energy Technology Data Exchange (ETDEWEB)

    Grothoff, Matthias; Gutberlet, Matthias [University of Leipzig - Heart Center, Department of Radiology, Leipzig (Germany); Hindricks, Gerhard; Sommer, Philipp; Hilbert, Sebastian [University of Leipzig - Heart Center, Department of Electrophysiology, Leipzig (Germany); Fleiter, Christian [Helios Klinikum Berlin-Buch, Department of Orthopaedic Surgery, Berlin (Germany); Schnackenburg, Bernhard [Philips Healthcare, Hamburg (Germany); Weiss, Steffen; Krueger, Sascha [Philips Innovative Technologies, Hamburg (Germany); Piorkowski, Christopher; Gaspar, Thomas [University of Dresden - Heart Center, Department of Electrophysiology, Dresden (Germany); Wedan, Steve; Lloyd, Thomas [Imricor Medical Systems, Burnsville, MN (United States)

    2017-05-15

    To evaluate the feasibility of performing comprehensive Cardiac Magnetic resonance (CMR) guided electrophysiological (EP) interventions in a porcine model encompassing left atrial access. After introduction of two femoral sheaths 14 swine (41 ± 3.6 kg) were transferred to a 1.5 T MR scanner. A three-dimensional whole-heart sequence was acquired followed by segmentation and the visualization of all heart chambers using an image-guidance platform. Two MR conditional catheters were inserted. The interventional protocol consisted of intubation of the coronary sinus, activation mapping, transseptal left atrial access (n = 4), generation of ablation lesions and eventually ablation of the atrioventricular (AV) node. For visualization of the catheter tip active tracking was used. Catheter positions were confirmed by passive real-time imaging. Total procedure time was 169 ± 51 minutes. The protocol could be completed in 12 swine. Two swine died from AV-ablation induced ventricular fibrillation. Catheters could be visualized and navigated under active tracking almost exclusively. The position of the catheter tips as visualized by active tracking could reliably be confirmed with passive catheter imaging. Comprehensive CMR-guided EP interventions including left atrial access are feasible in swine using active catheter tracking. (orig.)

  5. SU-E-P-49: Evaluation of Image Quality and Radiation Dose of Various Unenhanced Head CT Protocols

    International Nuclear Information System (INIS)

    Chen, L; Khan, M; Alapati, K; Hsieh, M; Barry, K

    2015-01-01

    Purpose: To evaluate the diagnostic value of various unenhanced head CT protocols and predicate acceptable radiation dose level for head CT exam. Methods: Our retrospective analysis included 3 groups, 20 patients per group, who underwent clinical routine unenhanced adult head CT examination. All exams were performed axially with 120 kVp. Three protocols, 380 mAs without iterative reconstruction and automAs, 340 mAs with iterative reconstruction without automAs, 340 mAs with iterative reconstruction and automAs, were applied on each group patients respectively. The images were reconstructed with H30, J30 for brain window and H60, J70 for bone window. Images acquired with three protocols were randomized and blindly reviewed by three radiologists. A 5 point scale was used to rate each exam The percentage of exam score above 3 and average scores of each protocol were calculated for each reviewer and tissue types. Results: For protocols without automAs, the average scores of bone window with iterative reconstruction were higher than those without iterative reconstruction for each reviewer although the radiation dose was 10 percentage lower. 100 percentage exams were scored 3 or higher and the average scores were above 4 for both brain and bone reconstructions. The CTDIvols are 64.4 and 57.8 mGy of 380 and 340 mAs, respectively. With automAs, the radiation dose varied with head size, resulting in 47.5 mGy average CTDIvol between 39.5 and 56.5 mGy. 93 and 98 percentage exams were scored great than 3 for brain and bone windows, respectively. The diagnostic confidence level and image quality of exams with AutomAs were less than those without AutomAs for each reviewer. Conclusion: According to these results, the mAs was reduced to 300 with automAs OFF for head CT exam. The radiation dose was 20 percentage lower than the original protocol and the CTDIvol was reduced to 51.2 mGy

  6. Protocol of image guided off-line using cone beam CT megavoltage; Protocolo de imagen guiada off-line mediante Cone Beam CT de megavoltaje

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Ruiz-Zorrilla, J.; Fernandez Leton, J. P.; Perez Moreno, J. M.; Zucca Aparicio, D.; Minambres Moro, A.

    2013-07-01

    The goal of image guided protocols offline is to reduce systematic errors in positioning of the patient in the treatment unit, being more important than the random errors, since the systematic have one contribution in the margin of the CTV to the PTV. This paper proposes a protocol for image guided offline with the different actions to take with their threshold values evaluated previously by anatomic location in a sample of 474 patients and 4821Cone beam Megavoltaje CT (CBCT). (Author)

  7. Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation.

    Science.gov (United States)

    Mekkaoui, Choukri; Huang, Shuning; Chen, Howard H; Dai, Guangping; Reese, Timothy G; Kostis, William J; Thiagalingam, Aravinda; Maurovich-Horvat, Pal; Ruskin, Jeremy N; Hoffmann, Udo; Jackowski, Marcel P; Sosnovik, David E

    2012-10-12

    The study of myofiber reorganization in the remote zone after myocardial infarction has been performed in 2D. Microstructural reorganization in remodeled hearts, however, can only be fully appreciated by considering myofibers as continuous 3D entities. The aim of this study was therefore to develop a technique for quantitative 3D diffusion CMR tractography of the heart, and to apply this method to quantify fiber architecture in the remote zone of remodeled hearts. Diffusion Tensor CMR of normal human, sheep, and rat hearts, as well as infarcted sheep hearts was performed ex vivo. Fiber tracts were generated with a fourth-order Runge-Kutta integration technique and classified statistically by the median, mean, maximum, or minimum helix angle (HA) along the tract. An index of tract coherence was derived from the relationship between these HA statistics. Histological validation was performed using phase-contrast microscopy. In normal hearts, the subendocardial and subepicardial myofibers had a positive and negative HA, respectively, forming a symmetric distribution around the midmyocardium. However, in the remote zone of the infarcted hearts, a significant positive shift in HA was observed. The ratio between negative and positive HA variance was reduced from 0.96 ± 0.16 in normal hearts to 0.22 ± 0.08 in the remote zone of the remodeled hearts (p layers of the myocardium. Tractography-based quantification, performed here for the first time in remodeled hearts, may provide a framework for assessing regional changes in the left ventricle following infarction.

  8. Cmr1/WDR76 defines a nuclear genotoxic stress body linking genome integrity and protein quality control

    DEFF Research Database (Denmark)

    Gallina, Irene; Colding, Camilla Skettrup; Henriksen, Peter

    2015-01-01

    DNA replication stress is a source of genomic instability. Here we identify changed mutation rate 1 (Cmr1) as a factor involved in the response to DNA replication stress in Saccharomyces cerevisiae and show that Cmr1-together with Mrc1/Claspin, Pph3, the chaperonin containing TCP1 (CCT) and 25...... other proteins-define a novel intranuclear quality control compartment (INQ) that sequesters misfolded, ubiquitylated and sumoylated proteins in response to genotoxic stress. The diversity of proteins that localize to INQ indicates that other biological processes such as cell cycle progression...... propose that Cmr1/WDR76 plays a role in the recovery from genotoxic stress through regulation of the turnover of sumoylated and phosphorylated proteins....

  9. Application of an Image Cytometry Protocol for Cellular and Mitochondrial Phenotyping on Fibroblasts from Patients with Inherited Disorders

    DEFF Research Database (Denmark)

    Fernandez-Guerra, Paula; Lund, Martin; Corydon, T J

    2015-01-01

    Cellular phenotyping of human dermal fibroblasts (HDFs) from patients with inherited diseases provides invaluable information for diagnosis, disease aetiology, prognosis and assessing of treatment options. Here we present a cell phenotyping protocol using image cytometry that combines measurements...... on a parallel one. We analysed HDFs from healthy individuals after treatment with various concentrations of hydrogen peroxide (H2O2) for different intervals, to mimic the physiological effects of oxidative stress. Our results show that cell number, viability, TRS and MMP decreased, while MSL increased both...... in a time- and concentration-dependent manner. To assess the use of our protocol for analysis of HDFs from patients with inherited diseases, we analysed HDFs from two patients with very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency (VLCADD), one with a severe clinical phenotype and one with a mild...

  10. Cell tracking and therapy evaluation of bone marrow monocytes and stromal cells using SPECT and CMR in a canine model of myocardial infarction

    Directory of Open Access Journals (Sweden)

    Merrifield Peter

    2009-04-01

    Full Text Available Abstract Background The clinical application of stem cell therapy for myocardial infarction will require the development of methods to monitor treatment and pre-clinical assessment in a large animal model, to determine its effectiveness and the optimum cell population, route of delivery, timing, and flow milieu. Objectives To establish a model for a in vivo tracking to monitor cell engraftment after autologous transplantation and b concurrent measurement of infarct evolution and remodeling. Methods We evaluated 22 dogs (8 sham controls, 7 treated with autologous bone marrow monocytes, and 7 with stromal cells using both imaging of 111Indium-tropolone labeled cells and late gadolinium enhancement CMR for up to12 weeks after a 3 hour coronary occlusion. Hearts were also examined using immunohistochemistry for capillary density and presence of PKH26 labeled cells. Results In vivo Indium imaging demonstrated an effective biological clearance half-life from the injection site of ~5 days. CMR demonstrated a pattern of progressive infarct shrinkage over 12 weeks, ranging from 67–88% of baseline values with monocytes producing a significant treatment effect. Relative infarct shrinkage was similar through to 6 weeks in all groups, following which the treatment effect was manifest. There was a trend towards an increase in capillary density with cell treatment. Conclusion This multi-modality approach will allow determination of the success and persistence of engraftment, and a correlation of this with infarct size shrinkage, regional function, and left ventricular remodeling. There were overall no major treatment effects with this particular model of transplantation immediately post-infarct.

  11. Prospective evaluation of a new protocol for the provisional use of perfusion imaging with exercise stress testing

    Energy Technology Data Exchange (ETDEWEB)

    Duvall, W.L. [Hartford Hospital, Division of Cardiology (Henry Low Heart Center), Hartford, CT (United States); Mount Sinai Medical Center, Division of Cardiology (Mount Sinai Heart), New York, NY (United States); Savino, John A.; Levine, Elliot J.; Croft, Lori B.; Henzlova, Milena J. [Mount Sinai Medical Center, Division of Cardiology (Mount Sinai Heart), New York, NY (United States); Hermann, Luke K. [Mount Sinai Medical Center, Department of Emergency Medicine, New York, NY (United States)

    2014-11-04

    Previous literature suggests that myocardial perfusion imaging (MPI) adds little to the prognosis of patients who exercise >10 metabolic equivalents (METs) during stress testing. With this in mind, we prospectively tested a provisional injection protocol in emergency department (ED) patients presenting for the evaluation of chest pain in which a patient would not receive an injection of radioisotope if adequate exercise was achieved without symptoms and a negative ECG response. All patients who presented to the ED over a 5-year period who were referred for stress testing as part of their ED evaluation were included. Patients considered for a provisional protocol were: exercise stress, age <65 years, no known coronary artery disease, and an interpretable rest ECG. Criteria for not injecting included a maximal predicted heart rate ≥85 %, ≥10 METs of exercise, no anginal symptoms during stress, and no ECG changes. Groups were compared based on stress test results, all-cause and cardiac mortality, follow-up cardiac testing, subsequent revascularization, and cost. A total of 965 patients were eligible with 192 undergoing exercise-only and 773 having perfusion imaging. After 41.6 ± 19.6 months of follow-up, all-cause mortality was similar in the exercise-only versus the exercise plus imaging group (2.6 % vs. 2.1 %, p = 0.59). There were no cardiac deaths in the exercise-only group. At 1 year there was no difference in the number of repeat functional stress tests (1.6 % vs. 2.1 %, p = 0.43), fewer angiograms (0 % vs. 4.0 %, p = 0.002), and a significantly lower cost (65 ± 332 vs 506 ± 1,991, p = 0.002; values are in US dollars) in the exercise-only group. The radiation exposure in the exercise plus imaging group was 8.4 ± 2.1 mSv. A provisional injection protocol has a very low mortality, few follow-up diagnostic tests, and lower cost compared to standard imaging protocols. If adopted it would decrease radiation exposure, save time and decrease health-care costs

  12. Prospective evaluation of a new protocol for the provisional use of perfusion imaging with exercise stress testing.

    Science.gov (United States)

    Duvall, W Lane; Savino, John A; Levine, Elliot J; Hermann, Luke K; Croft, Lori B; Henzlova, Milena J

    2015-02-01

    Previous literature suggests that myocardial perfusion imaging (MPI) adds little to the prognosis of patients who exercise >10 metabolic equivalents (METs) during stress testing. With this in mind, we prospectively tested a provisional injection protocol in emergency department (ED) patients presenting for the evaluation of chest pain in which a patient would not receive an injection of radioisotope if adequate exercise was achieved without symptoms and a negative ECG response. All patients who presented to the ED over a 5-year period who were referred for stress testing as part of their ED evaluation were included. Patients considered for a provisional protocol were: exercise stress, age heart rate ≥85%, ≥10 METs of exercise, no anginal symptoms during stress, and no ECG changes. Groups were compared based on stress test results, all-cause and cardiac mortality, follow-up cardiac testing, subsequent revascularization, and cost. A total of 965 patients were eligible with 192 undergoing exercise-only and 773 having perfusion imaging. After 41.6 ± 19.6 months of follow-up, all-cause mortality was similar in the exercise-only versus the exercise plus imaging group (2.6% vs. 2.1%, p = 0.59). There were no cardiac deaths in the exercise-only group. At 1 year there was no difference in the number of repeat functional stress tests (1.6% vs. 2.1%, p = 0.43), fewer angiograms (0% vs. 4.0%, p = 0.002), and a significantly lower cost ($65 ± $332 vs $506 ± $1,991, p = 0.002; values are in US dollars) in the exercise-only group. The radiation exposure in the exercise plus imaging group was 8.4 ± 2.1 mSv. A provisional injection protocol has a very low mortality, few follow-up diagnostic tests, and lower cost compared to standard imaging protocols. If adopted it would decrease radiation exposure, save time and decrease health-care costs without jeopardizing prognosis.

  13. Prospective evaluation of a new protocol for the provisional use of perfusion imaging with exercise stress testing

    International Nuclear Information System (INIS)

    Duvall, W.L.; Savino, John A.; Levine, Elliot J.; Croft, Lori B.; Henzlova, Milena J.; Hermann, Luke K.

    2015-01-01

    Previous literature suggests that myocardial perfusion imaging (MPI) adds little to the prognosis of patients who exercise >10 metabolic equivalents (METs) during stress testing. With this in mind, we prospectively tested a provisional injection protocol in emergency department (ED) patients presenting for the evaluation of chest pain in which a patient would not receive an injection of radioisotope if adequate exercise was achieved without symptoms and a negative ECG response. All patients who presented to the ED over a 5-year period who were referred for stress testing as part of their ED evaluation were included. Patients considered for a provisional protocol were: exercise stress, age <65 years, no known coronary artery disease, and an interpretable rest ECG. Criteria for not injecting included a maximal predicted heart rate ≥85 %, ≥10 METs of exercise, no anginal symptoms during stress, and no ECG changes. Groups were compared based on stress test results, all-cause and cardiac mortality, follow-up cardiac testing, subsequent revascularization, and cost. A total of 965 patients were eligible with 192 undergoing exercise-only and 773 having perfusion imaging. After 41.6 ± 19.6 months of follow-up, all-cause mortality was similar in the exercise-only versus the exercise plus imaging group (2.6 % vs. 2.1 %, p = 0.59). There were no cardiac deaths in the exercise-only group. At 1 year there was no difference in the number of repeat functional stress tests (1.6 % vs. 2.1 %, p = 0.43), fewer angiograms (0 % vs. 4.0 %, p = 0.002), and a significantly lower cost (65 ± 332 vs 506 ± 1,991, p = 0.002; values are in US dollars) in the exercise-only group. The radiation exposure in the exercise plus imaging group was 8.4 ± 2.1 mSv. A provisional injection protocol has a very low mortality, few follow-up diagnostic tests, and lower cost compared to standard imaging protocols. If adopted it would decrease radiation exposure, save time and decrease health-care costs

  14. A cross-platform survey of CT image quality and dose from routine abdomen protocols and a method to systematically standardize image quality.

    Science.gov (United States)

    Favazza, Christopher P; Duan, Xinhui; Zhang, Yi; Yu, Lifeng; Leng, Shuai; Kofler, James M; Bruesewitz, Michael R; McCollough, Cynthia H

    2015-11-07

    Through this investigation we developed a methodology to evaluate and standardize CT image quality from routine abdomen protocols across different manufacturers and models. The influence of manufacturer-specific automated exposure control systems on image quality was directly assessed to standardize performance across a range of patient sizes. We evaluated 16 CT scanners across our health system, including Siemens, GE, and Toshiba models. Using each practice's routine abdomen protocol, we measured spatial resolution, image noise, and scanner radiation output (CTDIvol). Axial and in-plane spatial resolutions were assessed through slice sensitivity profile (SSP) and modulation transfer function (MTF) measurements, respectively. Image noise and CTDIvol values were obtained for three different phantom sizes. SSP measurements demonstrated a bimodal distribution in slice widths: an average of 6.2  ±  0.2 mm using GE's 'Plus' mode reconstruction setting and 5.0  ±  0.1 mm for all other scanners. MTF curves were similar for all scanners. Average spatial frequencies at 50%, 10%, and 2% MTF values were 3.24  ±  0.37, 6.20  ±  0.34, and 7.84  ±  0.70 lp cm(-1), respectively. For all phantom sizes, image noise and CTDIvol varied considerably: 6.5-13.3 HU (noise) and 4.8-13.3 mGy (CTDIvol) for the smallest phantom; 9.1-18.4 HU and 9.3-28.8 mGy for the medium phantom; and 7.8-23.4 HU and 16.0-48.1 mGy for the largest phantom. Using these measurements and benchmark SSP, MTF, and image noise targets, CT image quality can be standardized across a range of patient sizes.

  15. Implementation of imaging of the national protocol for quality control in planning systems

    International Nuclear Information System (INIS)

    Caudepon Moreno, F.; Martin-Viera cueto, J. A.; Bodineau gil, C.; Benitez Villegas, E. M.; Casado Villalon, F. J.; Moreno Sainz, C.

    2011-01-01

    Quality control of the planning system (SP) plays a key role in quality assurance schemes that include all stages of the radiotherapy process.In this work we focus on the evidence detailing the ''Protocol for quality control in therapy planning systems with ionizing radiation of the SEFM in ''anatomical data acquisition (DA).

  16. Clinical Experience With Image-Guided Radiotherapy in an Accelerated Partial Breast Intensity-Modulated Radiotherapy Protocol

    International Nuclear Information System (INIS)

    Leonard, Charles E.; Tallhamer, Michael M.S.; Johnson, Tim; Hunter, Kari C.M.D.; Howell, Kathryn; Kercher, Jane; Widener, Jodi; Kaske, Terese; Paul, Devchand; Sedlacek, Scot; Carter, Dennis L.

    2010-01-01

    Purpose: To explore the feasibility of fiducial markers for the use of image-guided radiotherapy (IGRT) in an accelerated partial breast intensity modulated radiotherapy protocol. Methods and Materials: Nineteen patients consented to an institutional review board approved protocol of accelerated partial breast intensity-modulated radiotherapy with fiducial marker placement and treatment with IGRT. Patients (1 patient with bilateral breast cancer; 20 total breasts) underwent ultrasound guided implantation of three 1.2- x 3-mm gold markers placed around the surgical cavity. For each patient, table shifts (inferior/superior, right/left lateral, and anterior/posterior) and minimum, maximum, mean error with standard deviation were recorded for each of the 10 BID treatments. The dose contribution of daily orthogonal films was also examined. Results: All IGRT patients underwent successful marker placement. In all, 200 IGRT treatment sessions were performed. The average vector displacement was 4 mm (range, 2-7 mm). The average superior/inferior shift was 2 mm (range, 0-5 mm), the average lateral shift was 2 mm (range, 1-4 mm), and the average anterior/posterior shift was 3 mm (range, 1 5 mm). Conclusions: This study shows that the use of IGRT can be successfully used in an accelerated partial breast intensity-modulated radiotherapy protocol. The authors believe that this technique has increased daily treatment accuracy and permitted reduction in the margin added to the clinical target volume to form the planning target volume.

  17. Three-dimensional image analysis of the skull using variable CT scanning protocols-effect of slice thickness on measurement in the three-dimensional CT images

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ho Gul; Kim, Kee Deog; Park, Hyok; Kim, Dong Ook; Jeong, Hai Jo; Kim, Hee Joung; Yoo, Sun Kook; Kim, Yong Oock; Park, Chang Seo [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2004-07-15

    To evaluate the quantitative accuracy of three-dimensional (3D) images by mean of comparing distance measurements on the 3D images with direct measurements of dry human skull according to slice thickness and scanning modes. An observer directly measured the distance of 21 line items between 12 orthodontic landmarks on the skull surface using a digital vernier caliper and each was repeated five times. The dry human skull was scanned with a Helical CT with various slice thickness (3, 5, 7 mm) and acquisition modes (Conventional and Helical). The same observer measured corresponding distance of the same items on reconstructed 3D images with the internal program of V-works 4.0 (Cybermed Inc., Seoul, Korea). The quantitative accuracy of distance measurements were statistically evaluated with Wilcoxons' two-sample test. 11 line items in Conventional 3 mm, 8 in Helical 3 mm, 11 in Conventional 5 mm, 10 in Helical 5 mm, 5 in Conventional 7 mm and 9 in Helical 7 mm showed no statistically significant difference. Average difference between direct measurements and measurements on 3D CT images was within 2 mm in 19 line items of Conventional 3 mm. 20 of Helical 3 mm, 15 of Conventional 5 mm, 18 of Helical 5 mm, 11 of Conventional 7 mm and 16 of Helical 7 mm. Considering image quality and patient's exposure time, scanning protocol of Helical 5 mm is recommended for 3D image analysis of the skull in CT.

  18. A web service system supporting three-dimensional post-processing of medical images based on WADO protocol.

    Science.gov (United States)

    He, Longjun; Xu, Lang; Ming, Xing; Liu, Qian

    2015-02-01

    Three-dimensional post-processing operations on the volume data generated by a series of CT or MR images had important significance on image reading and diagnosis. As a part of the DIOCM standard, WADO service defined how to access DICOM objects on the Web, but it didn't involve three-dimensional post-processing operations on the series images. This paper analyzed the technical features of three-dimensional post-processing operations on the volume data, and then designed and implemented a web service system for three-dimensional post-processing operations of medical images based on the WADO protocol. In order to improve the scalability of the proposed system, the business tasks and calculation operations were separated into two modules. As results, it was proved that the proposed system could support three-dimensional post-processing service of medical images for multiple clients at the same moment, which met the demand of accessing three-dimensional post-processing operations on the volume data on the web.

  19. Recommendations for a Software Quality Assurance Plan for the CMR Facility at LANL

    International Nuclear Information System (INIS)

    Adams, K.; Matthews, S. D.; McQueen, M. A.

    1998-01-01

    The Nuclear Materials Technology (NMT) organizations 1 and 3 within the Chemical and Metallurgical Research (CMR) facility at the Los Alamos National Laboratory are working to achieve Waste Isolation Pilot Plant (WIPP) certification to enable them to transport their TRU waste to WIPP. This document is intended to provide not only recommendations to address the necessary software quality assurance activities to enable the NMT-1 and NMT-3 organizations to be WIPP compliant but is also meant to provide a template for the final Software Quality Assurance Plan (SQAP). This document specifically addresses software quality assurance for all software used in support of waste characterization and analysis. Since NMT-1 and NMT-3 currently have several operational software products that are used for waste characterization and analysis, these software quality assurance recommendations apply to the operations, maintenance and retirement of the software and the creation and development of any new software required for waste characterization and analyses

  20. The association of lesion eccentricity with plaque morphology and components in the superficial femoral artery: a high-spatial-resolution, multi-contrast weighted CMR study

    Directory of Open Access Journals (Sweden)

    Zhao Xihai

    2010-07-01

    Full Text Available Abstract Background Atherosclerotic plaque morphology and components are predictors of subsequent cardiovascular events. However, associations of plaque eccentricity with plaque morphology and plaque composition are unclear. This study investigated associations of plaque eccentricity with plaque components and morphology in the proximal superficial femoral artery using cardiovascular magnetic resonance (CMR. Methods Twenty-eight subjects with an ankle-brachial index less than 1.00 were examined with 1.5T high-spatial-resolution, multi-contrast weighted CMR. One hundred and eighty diseased locations of the proximal superficial femoral artery (about 40 mm were analyzed. The eccentric lesion was defined as [(Maximum wall thickness- Minimum wall thickness/Maximum wall thickness] ≥ 0.5. The arterial morphology and plaque components were measured using semi-automatic image analysis software. Results One hundred and fifteen locations were identified as eccentric lesions and sixty-five as concentric lesions. The eccentric lesions had larger wall but similar lumen areas, larger mean and maximum wall thicknesses, and more calcification and lipid rich necrotic core, compared to concentric lesions. For lesions with the same lumen area, the degree of eccentricity was associated with an increased wall area. Eccentricity (dichotomous as eccentric or concentric was independently correlated with the prevalence of calcification (odds ratio 3.78, 95% CI 1.47-9.70 after adjustment for atherosclerotic risk factors and wall area. Conclusions Plaque eccentricity is associated with preserved lumen size and advanced plaque features such as larger plaque burden, more lipid content, and increased calcification in the superficial femoral artery.

  1. SU-F-207-02: Use of Postmortem Subjects for Subjective Image Quality Assessment in Abdominal CT Protocols with Iterative Reconstruction

    International Nuclear Information System (INIS)

    Mench, A; Lipnharski, I; Carranza, C; Lamoureux, R; Smajdor, L; Cormack, B; Mohammed, T; Rill, L; Arreola, M; Sinclair, L

    2015-01-01

    Purpose: New radiation dose reduction technologies are emerging constantly in the medical imaging field. The latest of these technologies, iterative reconstruction (IR) in CT, presents the ability to reduce dose significantly and hence provides great opportunity for CT protocol optimization. However, without effective analysis of image quality, the reduction in radiation exposure becomes irrelevant. This work explores the use of postmortem subjects as an image quality assessment medium for protocol optimizations in abdominal CT. Methods: Three female postmortem subjects were scanned using the Abdomen-Pelvis (AP) protocol at reduced minimum tube current and target noise index (SD) settings of 12.5, 17.5, 20.0, and 25.0. Images were reconstructed using two strengths of iterative reconstruction. Radiologists and radiology residents from several subspecialties were asked to evaluate 8 AP image sets including the current facility default scan protocol and 7 scans with the parameters varied as listed above. Images were viewed in the soft tissue window and scored on a 3-point scale as acceptable, borderline acceptable, and unacceptable for diagnosis. The facility default AP scan was identified to the reviewer while the 7 remaining AP scans were randomized and de-identified of acquisition and reconstruction details. The observers were also asked to comment on the subjective image quality criteria they used for scoring images. This included visibility of specific anatomical structures and tissue textures. Results: Radiologists scored images as acceptable or borderline acceptable for target noise index settings of up to 20. Due to the postmortem subjects’ close representation of living human anatomy, readers were able to evaluate images as they would those of actual patients. Conclusion: Postmortem subjects have already been proven useful for direct CT organ dose measurements. This work illustrates the validity of their use for the crucial evaluation of image quality

  2. SU-F-207-02: Use of Postmortem Subjects for Subjective Image Quality Assessment in Abdominal CT Protocols with Iterative Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Mench, A [Salem Hospital, Salem, OR (United States); Lipnharski, I; Carranza, C; Lamoureux, R; Smajdor, L; Cormack, B; Mohammed, T; Rill, L; Arreola, M [University of Florida, Gainesville, FL (United States); Sinclair, L [Oregon Health & Science University, Portland, OR (United States)

    2015-06-15

    Purpose: New radiation dose reduction technologies are emerging constantly in the medical imaging field. The latest of these technologies, iterative reconstruction (IR) in CT, presents the ability to reduce dose significantly and hence provides great opportunity for CT protocol optimization. However, without effective analysis of image quality, the reduction in radiation exposure becomes irrelevant. This work explores the use of postmortem subjects as an image quality assessment medium for protocol optimizations in abdominal CT. Methods: Three female postmortem subjects were scanned using the Abdomen-Pelvis (AP) protocol at reduced minimum tube current and target noise index (SD) settings of 12.5, 17.5, 20.0, and 25.0. Images were reconstructed using two strengths of iterative reconstruction. Radiologists and radiology residents from several subspecialties were asked to evaluate 8 AP image sets including the current facility default scan protocol and 7 scans with the parameters varied as listed above. Images were viewed in the soft tissue window and scored on a 3-point scale as acceptable, borderline acceptable, and unacceptable for diagnosis. The facility default AP scan was identified to the reviewer while the 7 remaining AP scans were randomized and de-identified of acquisition and reconstruction details. The observers were also asked to comment on the subjective image quality criteria they used for scoring images. This included visibility of specific anatomical structures and tissue textures. Results: Radiologists scored images as acceptable or borderline acceptable for target noise index settings of up to 20. Due to the postmortem subjects’ close representation of living human anatomy, readers were able to evaluate images as they would those of actual patients. Conclusion: Postmortem subjects have already been proven useful for direct CT organ dose measurements. This work illustrates the validity of their use for the crucial evaluation of image quality

  3. Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation

    Directory of Open Access Journals (Sweden)

    Mekkaoui Choukri

    2012-10-01

    Full Text Available Abstract Background The study of myofiber reorganization in the remote zone after myocardial infarction has been performed in 2D. Microstructural reorganization in remodeled hearts, however, can only be fully appreciated by considering myofibers as continuous 3D entities. The aim of this study was therefore to develop a technique for quantitative 3D diffusion CMR tractography of the heart, and to apply this method to quantify fiber architecture in the remote zone of remodeled hearts. Methods Diffusion Tensor CMR of normal human, sheep, and rat hearts, as well as infarcted sheep hearts was performed ex vivo. Fiber tracts were generated with a fourth-order Runge-Kutta integration technique and classified statistically by the median, mean, maximum, or minimum helix angle (HA along the tract. An index of tract coherence was derived from the relationship between these HA statistics. Histological validation was performed using phase-contrast microscopy. Results In normal hearts, the subendocardial and subepicardial myofibers had a positive and negative HA, respectively, forming a symmetric distribution around the midmyocardium. However, in the remote zone of the infarcted hearts, a significant positive shift in HA was observed. The ratio between negative and positive HA variance was reduced from 0.96 ± 0.16 in normal hearts to 0.22 ± 0.08 in the remote zone of the remodeled hearts (p Conclusions A significant reorganization of the 3D fiber continuum is observed in the remote zone of remodeled hearts. The positive (rightward shift in HA in the remote zone is greatest in the subepicardium, but involves all layers of the myocardium. Tractography-based quantification, performed here for the first time in remodeled hearts, may provide a framework for assessing regional changes in the left ventricle following infarction.

  4. The structural revision of piericidin A by combination of CMR spectroscopic and biosynthetic studies

    International Nuclear Information System (INIS)

    Yoshida, Shigeo; Shiraishi, Shiro; Takahashi, Nobutaka

    1977-01-01

    The structure of piericidin A was reexamined by means of the CMR spectroscopy and the 13 C feeding studies, and the structure Ia was revised to IIa. This structure was further confirmed by the selective reduction of PA and by the mass spectral analysis. Twelve signals due to sp 3 carbons were readily assigned by selective 13 C-H decoupling technique. On the other hand, assignment of five signals due to sp 2 carbons carrying a proton could not be done by the technique because five olefinic protons appear in a narrow region in the PMR spectrum of PA. This problem was solved by the introduction of ''the graphical decoupling method''. Notwithstanding that the assignment of residual signals due to eight substituted sp 2 carbons, C-3, C-7, C-11 and the piridine carbons, could not be made at this stage, the analysis of the CMR spectrum of PA afforded enough information on the recognition of two carbons in question, C-4 and C-6. Thus the signals at delta 43.2 and delta 135.9 should be assigned to C-6 and C-4 in Ia, or C-4 and C-6 in IIa respectively. Then the feeding experiments of sodium acetate-1-13C were carried out. The spectrum of 13 C-enriched PA by acetate-1- 13 C shows a clear intensified signal at delta 43.2. On the other hand, another signal at delta 135.9 was enhanced by the feeding of propionate-1- 13 C. Obviously, these evidences indicate that the signal at delta 43.2 should be assigned to C-4 and that at delta 135.9 to C-6. Therefore, IIa represents the correct structure of PA, excluding Ia. (Iwakiri, K.)

  5. Comparison of dose and image quality in protocols abdominal CT using high an low KVP; Comparacion de dosis y calidad de imagen en protocolos abdominales de TC utilizando alto y bajo kilovoltaje

    Energy Technology Data Exchange (ETDEWEB)

    Mas Munoz, I.; Alejo Luque, L.; Corredoira Silva, E.; Sanchez Munoz, F. J.; Serrada Hierro, A.

    2013-07-01

    This paper compares quantitatively low kV Protocol with the conventional Protocol of abdomen, analysing the image quality with objective physical parameters and calculating the corresponding dummy dose reduction. (Author)

  6. Environmental assessment for the proposed CMR Building upgrades at the Los Alamos National Laboratory, Los Alamos, New Mexico. Final document

    International Nuclear Information System (INIS)

    1997-01-01

    In order to maintain its ability to continue to conduct uninterrupted radioactive and metallurgical research in a safe, secure, and environmentally sound manner, the US Department of Energy (DOE) proposes to upgrade the Los Alamos National Laboratory (LANL) Chemistry and Metallurgy Research (CMR) Building. The building was built in the early 1950s to provide a research and experimental facility for analytical chemistry, plutonium and uranium chemistry, and metallurgy. Today, research and development activities are performed involving nuclear materials. A variety of radioactive and chemical hazards are present. The CMR Building is nearing the end of its original design life and does not meet many of today's design codes and standards. The Proposed Action for this Environmental Assessment (EA) includes structural modifications to some portions of the CMR Building which do not meet current seismic criteria for a Hazard Category 2 Facility. Also included are upgrades and improvements in building ventilation, communications, monitoring, and fire protection systems. This EA analyzes the environmental effects of construction of the proposed upgrades. The Proposed Action will have no adverse effects upon agricultural and cultural resources, wetlands and floodplains, endangered and threatened species, recreational resources, or water resources. The Proposed Action would have negligible effects on human health and transportation, and would not pose a disproportionate adverse health or environmental impact on minority or low-income populations within an 80 kilometer (50 mile) radius of the CMR Building

  7. Environmental assessment for the proposed CMR Building upgrades at the Los Alamos National Laboratory, Los Alamos, New Mexico. Final document

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-04

    In order to maintain its ability to continue to conduct uninterrupted radioactive and metallurgical research in a safe, secure, and environmentally sound manner, the US Department of Energy (DOE) proposes to upgrade the Los Alamos National Laboratory (LANL) Chemistry and Metallurgy Research (CMR) Building. The building was built in the early 1950s to provide a research and experimental facility for analytical chemistry, plutonium and uranium chemistry, and metallurgy. Today, research and development activities are performed involving nuclear materials. A variety of radioactive and chemical hazards are present. The CMR Building is nearing the end of its original design life and does not meet many of today`s design codes and standards. The Proposed Action for this Environmental Assessment (EA) includes structural modifications to some portions of the CMR Building which do not meet current seismic criteria for a Hazard Category 2 Facility. Also included are upgrades and improvements in building ventilation, communications, monitoring, and fire protection systems. This EA analyzes the environmental effects of construction of the proposed upgrades. The Proposed Action will have no adverse effects upon agricultural and cultural resources, wetlands and floodplains, endangered and threatened species, recreational resources, or water resources. The Proposed Action would have negligible effects on human health and transportation, and would not pose a disproportionate adverse health or environmental impact on minority or low-income populations within an 80 kilometer (50 mile) radius of the CMR Building.

  8. Feasibility of an intracranial EEG-fMRI protocol at 3T: risk assessment and image quality.

    Science.gov (United States)

    Boucousis, Shannon M; Beers, Craig A; Cunningham, Cameron J B; Gaxiola-Valdez, Ismael; Pittman, Daniel J; Goodyear, Bradley G; Federico, Paolo

    2012-11-15

    Integrating intracranial EEG (iEEG) with functional MRI (iEEG-fMRI) may help elucidate mechanisms underlying the generation of seizures. However, the introduction of iEEG electrodes in the MR environment has inherent risk and data quality implications that require consideration prior to clinical use. Previous studies of subdural and depth electrodes have confirmed low risk under specific circumstances at 1.5T and 3T. However, no studies have assessed risk and image quality related to the feasibility of a full iEEG-fMRI protocol. To this end, commercially available platinum subdural grid/strip electrodes (4×5 grid or 1×8 strip) and 4 or 6-contact depth electrodes were secured to the surface of a custom-made phantom mimicking the conductivity of the human brain. Electrode displacement, temperature increase of electrodes and surrounding phantom material, and voltage fluctuations in electrode contacts were measured in a GE Discovery MR750 3T MR scanner during a variety of imaging sequences, typical of an iEEG-fMRI protocol. An electrode grid was also used to quantify the spatial extent of susceptibility artifact. The spatial extent of susceptibility artifact in the presence of an electrode was also assessed for typical imaging parameters that maximize BOLD sensitivity at 3T (TR=1500 ms; TE=30 ms; slice thickness=4mm; matrix=64×64; field-of-view=24 cm). Under standard conditions, all electrodes exhibited no measurable displacement and no clinically significant temperature increase (2.0°C) that in some cases exceeded 10°C. Induced voltages in the frequency range that could elicit neuronal stimulation (<10 kHz) were well below the threshold of 100 mV. fMRI signal intensity was significantly reduced within 20mm of the electrodes for the imaging parameters used in this study. Thus, for the conditions tested, a full iEEG-fMRI protocol poses a low risk at 3T; however, fMRI sensitivity may be reduced immediately adjacent to the electrodes. In addition, high SAR sequences

  9. Accumulative difference image protocol for particle tracking in fluorescence microscopy tested in mouse lymphonodes.

    Science.gov (United States)

    Villa, Carlo E; Caccia, Michele; Sironi, Laura; D'Alfonso, Laura; Collini, Maddalena; Rivolta, Ilaria; Miserocchi, Giuseppe; Gorletta, Tatiana; Zanoni, Ivan; Granucci, Francesca; Chirico, Giuseppe

    2010-08-17

    The basic research in cell biology and in medical sciences makes large use of imaging tools mainly based on confocal fluorescence and, more recently, on non-linear excitation microscopy. Substantially the aim is the recognition of selected targets in the image and their tracking in time. We have developed a particle tracking algorithm optimized for low signal/noise images with a minimum set of requirements on the target size and with no a priori knowledge of the type of motion. The image segmentation, based on a combination of size sensitive filters, does not rely on edge detection and is tailored for targets acquired at low resolution as in most of the in-vivo studies. The particle tracking is performed by building, from a stack of Accumulative Difference Images, a single 2D image in which the motion of the whole set of the particles is coded in time by a color level. This algorithm, tested here on solid-lipid nanoparticles diffusing within cells and on lymphocytes diffusing in lymphonodes, appears to be particularly useful for the cellular and the in-vivo microscopy image processing in which few a priori assumption on the type, the extent and the variability of particle motions, can be done.

  10. Accumulative difference image protocol for particle tracking in fluorescence microscopy tested in mouse lymphonodes.

    Directory of Open Access Journals (Sweden)

    Carlo E Villa

    Full Text Available The basic research in cell biology and in medical sciences makes large use of imaging tools mainly based on confocal fluorescence and, more recently, on non-linear excitation microscopy. Substantially the aim is the recognition of selected targets in the image and their tracking in time. We have developed a particle tracking algorithm optimized for low signal/noise images with a minimum set of requirements on the target size and with no a priori knowledge of the type of motion. The image segmentation, based on a combination of size sensitive filters, does not rely on edge detection and is tailored for targets acquired at low resolution as in most of the in-vivo studies. The particle tracking is performed by building, from a stack of Accumulative Difference Images, a single 2D image in which the motion of the whole set of the particles is coded in time by a color level. This algorithm, tested here on solid-lipid nanoparticles diffusing within cells and on lymphocytes diffusing in lymphonodes, appears to be particularly useful for the cellular and the in-vivo microscopy image processing in which few a priori assumption on the type, the extent and the variability of particle motions, can be done.

  11. The additional value of first pass myocardial perfusion imaging during peak dose of dobutamine stress cardiac MRI for the detection of myocardial ischemia

    NARCIS (Netherlands)

    Lubbers, Daniel D.; Janssen, Caroline H. C.; Kuijpers, Dirkjan; Van Dijkman, Paul R. M.; Overbosch, Jelle; Willems, Tineke P.; Oudkerk, Matthijs

    Purpose of this study was to assess the additional value of first pass myocardial perfusion imaging during peak dose of dobutamine stress Cardiac-MR (CMR). Dobutamine Stress CMR was performed in 115 patients with an inconclusive diagnosis of myocardial ischemia on a 1.5 T system (Magnetom Avanto,

  12. 2014 Korean Guidelines for Appropriate Utilization of Cardiovascular Magnetic Resonance Imaging: A Joint Report of the Korean Society of Cardiology and the Korean Society of Radiology

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yeonyee E. [Department of Cardiology, Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam 463-707 (Korea, Republic of); Hong, Yoo Jin [Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kim, Hyung-Kwan [Division of Cardiology, Department of Internal Medicine, Cardiovascular Center, Seoul National University College of Medicine, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of); Kim, Jeong A [Department of Radiology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang 411-706 (Korea, Republic of); Na, Jin Oh [Cardiovascular Center, Korea University Guro Hospital, Korea University College of Medicine, Seoul 152-703 (Korea, Republic of); Yang, Dong Hyun [Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Kim, Young Jin [Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Choi, Eui-Young [Division of Cardiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 135-720 (Korea, Republic of)

    2014-07-01

    Cardiac magnetic resonance (CMR) imaging is now widely used in several fields of cardiovascular disease assessment due to recent technical developments. CMR can give physicians information that cannot be found with other imaging modalities. However, there is no guideline which is suitable for Korean people for the use of CMR. Therefore, we have prepared a Korean guideline for the appropriate utilization of CMR to guide Korean physicians, imaging specialists, medical associates and patients to improve the overall medical system performances. By addressing CMR usage and creating these guidelines we hope to contribute towards the promotion of public health. This guideline is a joint report of the Korean Society of Cardiology and the Korean Society of Radiology.

  13. 2014 Korean guidelines for appropriate utilization of cardiovascular magnetic resonance imaging: A joint report of the Korean Society of Cardiology and the Korean Society of Radiology

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yeon Yee E. [Dept. of Cardiology, Cardiovascular Center, Seoul National University Bundang Hospital, Seoul (Korea, Republic of); Hong, Yoo Jin; Choi, Eui Young [Dept. of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); and others

    2015-04-15

    The use of cardiac magnetic resonance (CMR) imaging is increasing for the assessment of certain cardiovascular diseases, due to recent technical developments. CMR can give physicians information that cannot be found with other imaging modalities. However, there has been no guideline for the use of CMR in Korean people. Therefore, we have prepared a Korean guideline for the appropriate utilization of CMR to guide Korean physicians, imaging specialists, medical associates, and patients to improve the overall performances in medical system. By addressing CMR usage and creating these guidelines, we hope to contribute to the promotion of public health. This guideline is a joint report of the Korean Society of Cardiology and the Korean Society of Radiology.

  14. 2014 Korean guidelines for appropriate utilization of cardiovascular magnetic resonance imaging: A joint report of the Korean Society of Cardiology and the Korean Society of Radiology

    International Nuclear Information System (INIS)

    Yoon, Yeon Yee E.; Hong, Yoo Jin; Choi, Eui Young

    2015-01-01

    The use of cardiac magnetic resonance (CMR) imaging is increasing for the assessment of certain cardiovascular diseases, due to recent technical developments. CMR can give physicians information that cannot be found with other imaging modalities. However, there has been no guideline for the use of CMR in Korean people. Therefore, we have prepared a Korean guideline for the appropriate utilization of CMR to guide Korean physicians, imaging specialists, medical associates, and patients to improve the overall performances in medical system. By addressing CMR usage and creating these guidelines, we hope to contribute to the promotion of public health. This guideline is a joint report of the Korean Society of Cardiology and the Korean Society of Radiology.

  15. Optimization of whole-body PET imaging protocol for the detection of 18F-FDG overlappings in oncology

    International Nuclear Information System (INIS)

    Lartizien, C.

    2001-01-01

    Positron emission tomography (PET) is a nuclear imaging modality that allows studying in vivo cellular metabolic and biochemical processes. During the 90's, there has been a growing interest in the applications of PET in oncology related to the use of a glucose analog (FDG) labeled with the positron emitter 18 F. This tracer of the glucose metabolism is trapped in the cancer cells characterized by a deregulated glycolytic activity. This allows detecting tumors and metastases. The interest of PET in oncology has lead to develop imaging systems and protocols to perform whole-body acquisitions of the patient. Whole-body PET imaging has been limited in practice by the high level of statistical noise that affects the detection of small lesions due to limited radioactive dose injected to the patient and short acquisition time. In this context, our work focused on the optimization of detection performances in whole-body 18 F-FDG PET images. We have first developed an original method to evaluate detectability based on the psychophysical approach of the ROC methodology and adapted to the specificity of whole-body PET images. This method was used to evaluate detection performances of different reconstruction algorithms used for whole-body imaging. We have also studied the influence of the acquisition mode, namely the 2D and the 3D modes. To that purpose, we have used the NEC index to select relevant statistical acquisition conditions in both acquisition modes as a function of the injected dose to the patient. Then, we have compared the detection performances of these different acquisition conditions based on our psychophysical evaluation technique. (author) [fr

  16. CMR of EEX? Van samenloop, litispendentie en het vrij verkeer van beslissingen in Europa. Hof van Justitie EU 4 mei 2010, zaak C-533/08 (TNT Express/AXA)

    NARCIS (Netherlands)

    M.A.I.H. Hoeks (Marian)

    2011-01-01

    textabstractAbstract The seed from which the problem sprouted in the TNT-AXA case is the fact that the CMR, an international road carriage convention, refers to national law in Article 29 CMR. This Article determines that if the CMR carrier has caused damage to the cargo ‘by such default on his

  17. A cross-platform survey of CT image quality and dose from routine abdomen protocols and a method to systematically standardize image quality

    International Nuclear Information System (INIS)

    Favazza, Christopher P; Duan, Xinhui; Zhang, Yi; Yu, Lifeng; Leng, Shuai; Kofler, James M; Bruesewitz, Michael R; McCollough, Cynthia H

    2015-01-01

    Through this investigation we developed a methodology to evaluate and standardize CT image quality from routine abdomen protocols across different manufacturers and models. The influence of manufacturer-specific automated exposure control systems on image quality was directly assessed to standardize performance across a range of patient sizes. We evaluated 16 CT scanners across our health system, including Siemens, GE, and Toshiba models. Using each practice’s routine abdomen protocol, we measured spatial resolution, image noise, and scanner radiation output (CTDI vol ). Axial and in-plane spatial resolutions were assessed through slice sensitivity profile (SSP) and modulation transfer function (MTF) measurements, respectively. Image noise and CTDI vol values were obtained for three different phantom sizes. SSP measurements demonstrated a bimodal distribution in slice widths: an average of 6.2  ±  0.2 mm using GE’s ‘Plus’ mode reconstruction setting and 5.0  ±  0.1 mm for all other scanners. MTF curves were similar for all scanners. Average spatial frequencies at 50%, 10%, and 2% MTF values were 3.24  ±  0.37, 6.20  ±  0.34, and 7.84  ±  0.70 lp cm −1 , respectively. For all phantom sizes, image noise and CTDI vol varied considerably: 6.5–13.3 HU (noise) and 4.8–13.3 mGy (CTDI vol ) for the smallest phantom; 9.1–18.4 HU and 9.3–28.8 mGy for the medium phantom; and 7.8–23.4 HU and 16.0–48.1 mGy for the largest phantom. Using these measurements and benchmark SSP, MTF, and image noise targets, CT image quality can be standardized across a range of patient sizes. (paper)

  18. Diagnostic performance of the three-dimensional fast spin echo-Cube sequence in comparison with a conventional imaging protocol in evaluation of the lachrymal drainage system

    International Nuclear Information System (INIS)

    Zhang, Jing; Chen, Lang; Wang, Qiu-Xia; Zhu, Wen-Zhen; Luo, Xin; Peng, Li; Liu, Rong; Xiong, Wei

    2015-01-01

    To compare the three-dimensional (3D)-fast spin-echo (FSE)-Cube with a conventional imaging protocol in evaluation of dacryostenosis. Thirty-three patients with epiphora underwent examinations using Cube magnetic resonance dacryocystography (MRD) and a conventional protocol, which included 3D fast-recovery fast spin-echo (FRFSE) MRD and two-dimensional (2D)-FSE sequences at 3.0 T. Using lachrymal endoscopic findings as the reference standard, we calculated the sensitivity and specificity of both protocols for detecting lachrymal drainage system (LDS) obstruction and their accuracies in depicting the level of obstruction. Comparable coronal and axial images were selected for bot sequences. Two neuroradiologists graded paired images for blurring, artefacts, anatomic details, and overall image quality. The two methods showed no significant difference in sensitivity (89.5 % vs. 94.7 %; p =0.674), specificity (64.3 %; p =1) or accuracy (86.8 %; p =1) in detecting or depicting LDS obstruction. Blurring and artefacts were significantly better on 2D-FSE images (p 0.05). In comparison with the conventional protocol, Cube MRD demonstrates satisfactory image quality and similar diagnostic capability for cases of possible LDS disease. (orig.)

  19. Automatic segmentation of myocardium at risk from contrast enhanced SSFP CMR: validation against expert readers and SPECT

    International Nuclear Information System (INIS)

    Tufvesson, Jane; Carlsson, Marcus; Aletras, Anthony H.; Engblom, Henrik; Deux, Jean-François; Koul, Sasha; Sörensson, Peder; Pernow, John; Atar, Dan; Erlinge, David; Arheden, Håkan; Heiberg, Einar

    2016-01-01

    Efficacy of reperfusion therapy can be assessed as myocardial salvage index (MSI) by determining the size of myocardium at risk (MaR) and myocardial infarction (MI), (MSI = 1-MI/MaR). Cardiovascular magnetic resonance (CMR) can be used to assess MI by late gadolinium enhancement (LGE) and MaR by either T2-weighted imaging or contrast enhanced SSFP (CE-SSFP). Automatic segmentation algorithms have been developed and validated for MI by LGE as well as for MaR by T2-weighted imaging. There are, however, no algorithms available for CE-SSFP. Therefore, the aim of this study was to develop and validate automatic segmentation of MaR in CE-SSFP. The automatic algorithm applies surface coil intensity correction and classifies myocardial intensities by Expectation Maximization to define a MaR region based on a priori regional criteria, and infarct region from LGE. Automatic segmentation was validated against manual delineation by expert readers in 183 patients with reperfused acute MI from two multi-center randomized clinical trials (RCT) (CHILL-MI and MITOCARE) and against myocardial perfusion SPECT in an additional set (n = 16). Endocardial and epicardial borders were manually delineated at end-diastole and end-systole. Manual delineation of MaR was used as reference and inter-observer variability was assessed for both manual delineation and automatic segmentation of MaR in a subset of patients (n = 15). MaR was expressed as percent of left ventricular mass (%LVM) and analyzed by bias (mean ± standard deviation). Regional agreement was analyzed by Dice Similarity Coefficient (DSC) (mean ± standard deviation). MaR assessed by manual and automatic segmentation were 36 ± 10 % and 37 ± 11 %LVM respectively with bias 1 ± 6 %LVM and regional agreement DSC 0.85 ± 0.08 (n = 183). MaR assessed by SPECT and CE-SSFP automatic segmentation were 27 ± 10 %LVM and 29 ± 7 %LVM respectively with bias 2 ± 7 %LVM. Inter-observer variability was 0 ± 3 %LVM for manual delineation and

  20. ZOOM or Non-ZOOM? Assessing Spinal Cord Diffusion Tensor Imaging Protocols for Multi-Centre Studies.

    Directory of Open Access Journals (Sweden)

    Rebecca S Samson

    Full Text Available The purpose of this study was to develop and evaluate two spinal cord (SC diffusion tensor imaging (DTI protocols, implemented at multiple sites (using scanners from two different manufacturers, one available on any clinical scanner, and one using more advanced options currently available in the research setting, and to use an automated processing method for unbiased quantification. DTI parameters are sensitive to changes in the diseased SC. However, imaging the cord can be technically challenging due to various factors including its small size, patient-related and physiological motion, and field inhomogeneities. Rapid acquisition sequences such as Echo Planar Imaging (EPI are desirable but may suffer from image distortions. We present a multi-centre comparison of two acquisition protocols implemented on scanners from two different vendors (Siemens and Philips, one using a reduced field-of-view (rFOV EPI sequence, and one only using options available on standard clinical scanners such as outer volume suppression (OVS. Automatic analysis was performed with the Spinal Cord Toolbox for unbiased and reproducible quantification of DTI metrics in the white matter. Images acquired using the rFOV sequence appear less distorted than those acquired using OVS alone. SC DTI parameter values obtained using both sequences at all sites were consistent with previous measurements made at 3T. For the same scanner manufacturer, DTI parameter inter-site SDs were smaller for the rFOV sequence compared to the OVS sequence. The higher inter-site reproducibility (for the same manufacturer and acquisition details, i.e. ZOOM data acquired at the two Philips sites of rFOV compared to the OVS sequence supports the idea that making research options such as rFOV more widely available would improve accuracy of measurements obtained in multi-centre clinical trials. Future multi-centre studies should also aim to match the rFOV technique and signal-to-noise ratios in all

  1. Magnetic Resonance and Ultrasound Image Fusion Supported Transperineal Prostate Biopsy Using the Ginsburg Protocol: Technique, Learning Points, and Biopsy Results.

    Science.gov (United States)

    Hansen, Nienke; Patruno, Giulio; Wadhwa, Karan; Gaziev, Gabriele; Miano, Roberto; Barrett, Tristan; Gnanapragasam, Vincent; Doble, Andrew; Warren, Anne; Bratt, Ola; Kastner, Christof

    2016-08-01

    Prostate biopsy supported by transperineal image fusion has recently been developed as a new method to the improve accuracy of prostate cancer detection. To describe the Ginsburg protocol for transperineal prostate biopsy supported by multiparametric magnetic resonance imaging (mpMRI) and transrectal ultrasound (TRUS) image fusion, provide learning points for its application, and report biopsy results. The article is supplemented by a Surgery in Motion video. This single-centre retrospective outcome study included 534 patients from March 2012 to October 2015. A total of 107 had no previous prostate biopsy, 295 had benign TRUS-guided biopsies, and 159 were on active surveillance for low-risk cancer. A Likert scale reported mpMRI for suspicion of cancer from 1 (no suspicion) to 5 (cancer highly likely). Transperineal biopsies were obtained under general anaesthesia using BiopSee fusion software (Medcom, Darmstadt, Germany). All patients had systematic biopsies, two cores from each of 12 anatomic sectors. Likert 3-5 lesions were targeted with a further two cores per lesion. Any cancer and Gleason score 7-10 cancer on biopsy were noted. Descriptive statistics and positive predictive values (PPVs) and negative predictive values (NPVs) were calculated. The detection rate of Gleason score 7-10 cancer was similar across clinical groups. Likert scale 3-5 MRI lesions were reported in 378 (71%) of the patients. Cancer was detected in 249 (66%) and Gleason score 7-10 cancer was noted in 157 (42%) of these patients. PPV for detecting 7-10 cancer was 0.15 for Likert score 3, 0.43 for score 4, and 0.63 for score 5. NPV of Likert 1-2 findings was 0.87 for Gleason score 7-10 and 0.97 for Gleason score ≥4+3=7 cancer. Limitations include lack of data on complications. Transperineal prostate biopsy supported by MRI/TRUS image fusion using the Ginsburg protocol yielded high detection rates of Gleason score 7-10 cancer. Because the NPV for excluding Gleason score 7-10 cancer was very

  2. Availability and performance of image/video-based vital signs monitoring methods: a systematic review protocol.

    Science.gov (United States)

    Harford, Mirae; Catherall, Jacqueline; Gerry, Stephen; Young, Duncan; Watkinson, Peter

    2017-10-25

    For many vital signs, monitoring methods require contact with the patient and/or are invasive in nature. There is increasing interest in developing still and video image-guided monitoring methods that are non-contact and non-invasive. We will undertake a systematic review of still and video image-based monitoring methods. We will perform searches in multiple databases which include MEDLINE, Embase, CINAHL, Cochrane library, IEEE Xplore and ACM Digital Library. We will use OpenGrey and Google searches to access unpublished or commercial data. We will not use language or publication date restrictions. The primary goal is to summarise current image-based vital signs monitoring methods, limited to heart rate, respiratory rate, oxygen saturations and blood pressure. Of particular interest will be the effectiveness of image-based methods compared to reference devices. Other outcomes of interest include the quality of the method comparison studies with respect to published reporting guidelines, any limitations of non-contact non-invasive technology and application in different populations. To the best of our knowledge, this is the first systematic review of image-based non-contact methods of vital signs monitoring. Synthesis of currently available technology will facilitate future research in this highly topical area. PROSPERO CRD42016029167.

  3. Availability and performance of image/video-based vital signs monitoring methods: a systematic review protocol

    Directory of Open Access Journals (Sweden)

    Mirae Harford

    2017-10-01

    Full Text Available Abstract Background For many vital signs, monitoring methods require contact with the patient and/or are invasive in nature. There is increasing interest in developing still and video image-guided monitoring methods that are non-contact and non-invasive. We will undertake a systematic review of still and video image-based monitoring methods. Methods We will perform searches in multiple databases which include MEDLINE, Embase, CINAHL, Cochrane library, IEEE Xplore and ACM Digital Library. We will use OpenGrey and Google searches to access unpublished or commercial data. We will not use language or publication date restrictions. The primary goal is to summarise current image-based vital signs monitoring methods, limited to heart rate, respiratory rate, oxygen saturations and blood pressure. Of particular interest will be the effectiveness of image-based methods compared to reference devices. Other outcomes of interest include the quality of the method comparison studies with respect to published reporting guidelines, any limitations of non-contact non-invasive technology and application in different populations. Discussion To the best of our knowledge, this is the first systematic review of image-based non-contact methods of vital signs monitoring. Synthesis of currently available technology will facilitate future research in this highly topical area. Systematic review registration PROSPERO CRD42016029167

  4. Detection of furcation involvement using periapical radiography and 2 cone-beam computed tomography imaging protocols with and without a metallic post: An animal study

    Energy Technology Data Exchange (ETDEWEB)

    Salineiro, Fernanda Cristina Sales; Gialain, Ivan Onone; Kobayashi-Velasco, Solange; Pannuti, Claudio Mendes; Cavalcanti, Marcelo Gusmao Paraiso [Dept. of Stomatology, School of Dentistry, University of Sao Paulo, Sao Paulo (Brazil)

    2017-03-15

    The purpose of this study was to assess the accuracy, sensitivity, and specificity of the diagnosis of incipient furcation involvement with periapical radiography (PR) and 2 cone-beam computed tomography (CBCT) imaging protocols, and to test metal artifact interference. Mandibular second molars in 10 macerated pig mandibles were divided into those that showed no furcation involvement and those with lesions in the furcation area. Exams using PR and 2 different CBCT imaging protocols were performed with and without a metallic post. Each image was analyzed twice by 2 observers who rated the absence or presence of furcation involvement according to a 5-point scale. Receiver operating characteristic (ROC) curves were used to evaluate the accuracy, sensitivity, and specificity of the observations. The accuracy of the CBCT imaging protocols ranged from 67.5% to 82.5% in the images obtained with a metallic post and from 72.5% to 80% in those without a metallic post. The accuracy of PR ranged from 37.5% to 55% in the images with a metallic post and from 42.5% to 62.5% in those without a metallic post. The area under the ROC curve values for the CBCT imaging protocols ranged from 0.813 to 0.802, and for PR ranged from 0.503 to 0.448. Both CBCT imaging protocols showed higher accuracy, sensitivity, and specificity than PR in the detection of incipient furcation involvement. Based on these results, CBCT may be considered a reliable tool for detecting incipient furcation involvement following a clinical periodontal exam, even in the presence of a metallic post.

  5. Improved identification of cranial nerves using paired-agent imaging: topical staining protocol optimization through experimentation and simulation

    Science.gov (United States)

    Torres, Veronica C.; Wilson, Todd; Staneviciute, Austeja; Byrne, Richard W.; Tichauer, Kenneth M.

    2018-03-01

    Skull base tumors are particularly difficult to visualize and access for surgeons because of the crowded environment and close proximity of vital structures, such as cranial nerves. As a result, accidental nerve damage is a significant concern and the likelihood of tumor recurrence is increased because of more conservative resections that attempt to avoid injuring these structures. In this study, a paired-agent imaging method with direct administration of fluorophores is applied to enhance cranial nerve identification. Here, a control imaging agent (ICG) accounts for non-specific uptake of the nerve-targeting agent (Oxazine 4), and ratiometric data analysis is employed to approximate binding potential (BP, a surrogate of targeted biomolecule concentration). For clinical relevance, animal experiments and simulations were conducted to identify parameters for an optimized stain and rinse protocol using the developed paired-agent method. Numerical methods were used to model the diffusive and kinetic behavior of the imaging agents in tissue, and simulation results revealed that there are various combinations of stain time and rinse number that provide improved contrast of cranial nerves, as suggested by optimal measures of BP and contrast-to-noise ratio.

  6. Diagnostic accuracy of an MRI protocol of the knee accelerated through parallel imaging in correlation to arthroscopy

    International Nuclear Information System (INIS)

    Schnaiter, Johannes Walter; McKenna-Kuettner, Axel; Roemer, Frank; May, Matthias Stefan; Janka, Rolf; Uder, Michael; Wuest, Wolfgang; Patzak, Hans-Joachim

    2018-01-01

    Parallel imaging allows for a considerable shortening of examination times. Limited data is available about the diagnostic accuracy of an accelerated knee MRI protocol based on parallel imaging evaluating all knee joint compartments in a large patient population compared to arthroscopy. 162 consecutive patients with a knee MRI (1.5 T, Siemens Aera) and arthroscopy were included. The total MRI scan time was less than 9 minutes. Meniscus and cartilage injuries, cruciate ligament lesions, loose joint bodies and medial patellar plicae were evaluated. Sensitivity (SE), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV), as well as diagnostic accuracy were determined. For the medial meniscus, the values were: SE 97 %, SP 88 %, PPV 94 %, and NPV 94 %. For the lateral meniscus the values were: SE 77 %, SP 99 %, PPV 98 %, and NPV 89 %. For cartilage injuries the values were: SE 72 %, SP 80 %, PPV 86 %, and NPV 61 %. For the anterior cruciate ligament the values were: SE 90 %, SP 94 %, PPV 77 %, and NPV 98 %, while all values were 100 % for the posterior cruciate ligament. For loose bodies the values were: SE 48 %, SP 96 %, PPV 62 %, and NPV 93 %, and for the medial patellar plicae the values were: SE 57 %, SP 88 %, PPV 18 %, and NPV 98 %. A knee MRI examination with parallel imaging and a scan time of less than 9 minutes delivers reliable results with high diagnostic accuracy.

  7. Simulation of a multi-detector gamma camera for validation protocols of quantification the activity from SPECT images

    International Nuclear Information System (INIS)

    Lozano Sanchez, A.; Calderon Marin, C.; Gonzalez Gonzalez, J.

    2015-01-01

    The main sources that decreasing accuracy in the estimation of internal absorbed dose has been identified in the methods for the quantification of cumulated activity from scintigraphic imaging, likes the corrections required by the physical and instrumental phenomena related to the formation of those images. The results of the simulation of a dual detector gamma camera E.cam SIEMENS using the Monte Carlo code SIMIND to obtain tomographic SPECT projections are presented here. SIMIND will allow dealing with the contribution of physical interactions and instrumental effects during simulations. Energy resolution, spatial resolution and sensitivity planar were determined with real and simulated systems. The relative differences did not exceed 10%. Energy spectra simulated under different conditions (source in air and water) with the inclusion of interactions in the collimator and phantom were compared. The tomographic sensitivity of a volumetric phantom containing radioactive solutions of 99m Tc and 131 I were determined from real and simulated SPECT images. Two processing protocols were considered: with scatter correction ( 99m Tc dual energy window method and 131 I were calculated after corrections. The results, expressed in terms of the differences relative to the well-know activity value in the phantom inserts improves when attenuation and scattering corrections are applied, obtaining good agreement between the results for real and simulated systems. (Author)

  8. Magnetic resonance imaging for cerebral lesions during minimal invasive mitral valve surgery: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Barbero, Cristina; Ricci, Davide; Cura Stura, Erik; Pellegrini, Augusto; Marchetto, Giovanni; ElQarra, Suad; Boffini, Massimo; Passera, Roberto; Valentini, Maria Consuelo; Rinaldi, Mauro

    2017-02-21

    Recent data have highlighted a higher rate of neurological injuries in minimal invasive mitral valve surgery (MIMVS) compared with the standard sternotomy approach; therefore, the role of specific clamping techniques and perfusion strategies on the occurrence of this complication is a matter of discussion in the medical literature. The purpose of this trial is to prospectively evaluate major, minor and silent neurological events in patients undergoing right mini-thoracotomy mitral valve surgery using retrograde perfusion and an endoaortic clamp or a transthoracic clamp. A prospective, blinded, randomized controlled study on the rate of neurological embolizations during MIMVS started at the University of Turin in June 2014. Major, minor and silent neurological events are being investigated through standard neurological evaluation and magnetic resonance imaging assessment. The magnetic resonance imaging protocol includes conventional sequences for the morphological and quantitative assessment and nonconventional sequences for the white matter microstructural evaluation. Imaging studies are performed before surgery as baseline assessment and on the third postoperative day and, in patients who develop postoperative ischemic lesions, after 6 months. Despite recent concerns raised about the endoaortic setting with retrograde perfusion, we expect to show equivalence in terms of neurological events of this technique compared with the transthoracic clamp in a selected cohort of patients. With the first results expected in December 2016 the findings would be of help in confirming the efficacy and safety of MIMVS. ClinicalTrials.gov, Identifier: NCT02818166 . Registered on 8 February 2016 - trial retrospectively registered.

  9. Positron emission tomography-computed tomography protocol considerations for head and neck cancer imaging.

    Science.gov (United States)

    Escott, Edward J

    2008-08-01

    Positron emission tomographic-computed tomographic (PET-CT) imaging of patients with primary head and neck cancers has become an established approach for staging and restaging, as well as radiation therapy planning. The inherent co-registration of PET and CT images made possible by the integrated PET-CT scanner is particularly valuable in head and neck cancer imaging due to the complex and closely situated anatomy in this part of the body, the varied sources of physiologic and benign 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) tracer uptake that occurs in the neck, and the varied and complex posttreatment appearance of the neck. Careful optimization of both the CT and the PET portion of the examination is essential to insure the most accurate and clinically valuable interpretation of these examinations.

  10. Sinus of Valsalva aneurysm and bicuspid aortic valve: detection and mechanism by cardiac magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Jen Li Looi

    2011-09-01

    Full Text Available Cardiac magnetic resonance imaging (CMR demonstrated a sinus of Valsalva aneurysm (SVA with severe dilatation of the right coronary sinus in association with a congenital bicuspid aortic valve (BAV and subaortic membrane. The SVA had not been apparent on echocardiography as the dilatation was outside standard echo image planes. On both CMR and echo, blood flow was eccentrically directed into the right coronary sinus by the domed posterior leaflet of the BAV. The impact of the aortic jet on the wall of the right coronary sinus is probably important in the aetiology of the sinus dilatation. CMR proved valuable in demonstrating the SVA and understanding its aetiology.

  11. Sinus of Valsalva aneurysm and bicuspid aortic valve: detection and mechanism by cardiac magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Jen Li Looi

    2011-10-01

    Full Text Available Cardiac magnetic resonance imaging (CMR demonstrated a sinus of Valsalva aneurysm (SVA with severe dilatation of the right coronary sinus in association with a congenital bicuspid aortic valve (BAV and subaortic membrane. The SVA had not been apparent on echocardiography as the dilatation was outside standard echo image planes. On both CMR and echo, blood flow was eccentrically directed into the right coronary sinus by the domed posterior leaflet of the BAV. The impact of the aortic jet on the wall of the right coronary sinus is probably important in the aetiology of the sinus dilatation. CMR proved valuable in demonstrating the SVA and understanding its aetiology.

  12. Three-dimensional structure determination protocol for noncrystalline biomolecules using x-ray free-electron laser diffraction imaging.

    Science.gov (United States)

    Oroguchi, Tomotaka; Nakasako, Masayoshi

    2013-02-01

    Coherent and intense x-ray pulses generated by x-ray free-electron laser (XFEL) sources are paving the way for structural determination of noncrystalline biomolecules. However, due to the small scattering cross section of electrons for x rays, the available incident x-ray intensity of XFEL sources, which is currently in the range of 10(12)-10(13) photons/μm(2)/pulse, is lower than that necessary to perform single-molecule diffraction experiments for noncrystalline biomolecules even with the molecular masses of megadalton and submicrometer dimensions. Here, we propose an experimental protocol and analysis method for visualizing the structure of those biomolecules by the combined application of coherent x-ray diffraction imaging and three-dimensional reconstruction methods. To compensate the small scattering cross section of biomolecules, in our protocol, a thin vitreous ice plate containing several hundred biomolecules/μm(2) is used as sample, a setup similar to that utilized by single-molecule cryoelectron microscopy. The scattering cross section of such an ice plate is far larger than that of a single particle. The images of biomolecules contained within irradiated areas are then retrieved from each diffraction pattern, and finally provide the three-dimensional electron density model. A realistic atomic simulation using large-scale computations proposed that the three-dimensional structure determination of the 50S ribosomal subunit embedded in a vitreous ice plate is possible at a resolution of 0.8 nm when an x-ray beam of 10(16) photons/500×500 nm(2)/pulse is available.

  13. Consensus recommendations for a standardized Brain Tumor Imaging Protocol in clinical trials

    NARCIS (Netherlands)

    B.M. Ellingson (Benjamin M.); M. Bendszus (Martin); J. Boxerman (Jerrold); D. Barboriak (Daniel); B.J. Erickson (Bradley J.); M. Smits (Marion); S.J. Nelson (Sarah J.); E. Gerstner (Elizabeth); B. Alexander (Brian); G. Goldmacher (Gregory); W. Wick (Wolfgang); M.A. Vogelbaum (Michael); M. Weller (Michael); E. Galanis (Evanthia); J. Kalpathy-Cramer (Jayashree); L. Shankar; P. Jacobs (Paula); W.B. Pope (Whitney B.); D. Yang (Dewen); C. Chung (Caroline); R.H. Knopp; S. Cha (Soonme); M.J. van den Bent (Martin); S.M. Chang (Susan); W.K. Al Yung; T.F. Cloughesy (Timothy F.); P.Y. Wen (Patrick Y.); M.R. Gilbert (Mark R.); A. Whitney (Andrew); D. Sandak (David); A. Musella (Al); C. Haynes (Chas); M. Wallace (Max); D.F. Arons (David F.); A. Kingston (Ann)

    2015-01-01

    textabstractA recent joint meeting was held on January 30, 2014, with the US Food and Drug Administration (FDA), National Cancer Institute (NCI), clinical scientists, imaging experts, pharmaceutical and biotech companies, clinical trials cooperative groups, and patient advocate groups to discuss

  14. Evaluation of the articular cartilage of the knee joint: value of adding a T2 mapping sequence to a routine MR imaging protocol.

    Science.gov (United States)

    Kijowski, Richard; Blankenbaker, Donna G; Munoz Del Rio, Alejandro; Baer, Geoffrey S; Graf, Ben K

    2013-05-01

    To determine whether the addition of a T2 mapping sequence to a routine magnetic resonance (MR) imaging protocol could improve diagnostic performance in the detection of surgically confirmed cartilage lesions within the knee joint at 3.0 T. This prospective study was approved by the institutional review board, and the requirement to obtain informed consent was waived. The study group consisted of 150 patients (76 male and 74 female patients with an average age of 41.2 and 41.5 years, respectively) who underwent MR imaging and arthroscopy of the knee joint. MR imaging was performed at 3.0 T by using a routine protocol with the addition of a sagittal T2 mapping sequence. Images from all MR examinations were reviewed in consensus by two radiologists before surgery to determine the presence or absence of cartilage lesions on each articular surface, first by using the routine MR protocol alone and then by using the routine MR protocol with T2 maps. Each articular surface was then evaluated at arthroscopy. Generalized estimating equation models were used to compare the sensitivity and specificity of the routine MR imaging protocol with and without T2 maps in the detection of surgically confirmed cartilage lesions. The sensitivity and specificity in the detection of 351 cartilage lesions were 74.6% and 97.8%, respectively, for the routine MR protocol alone and 88.9% and 93.1% for the routine MR protocol with T2 maps. Differences in sensitivity and specificity were statistically significant (P T2 maps to the routine MR imaging protocol significantly improved the sensitivity in the detection of 24 areas of cartilage softening (from 4.2% to 62%, P T2 mapping sequence to a routine MR protocol at 3.0 T improved sensitivity in the detection of cartilage lesions within the knee joint from 74.6% to 88.9%, with only a small reduction in specificity. The greatest improvement in sensitivity with use of the T2 maps was in the identification of early cartilage degeneration. © RSNA

  15. Preliminary Studies for a CBCT Imaging Protocol for Offline Organ Motion Analysis: Registration Software Validation and CTDI Measurements

    International Nuclear Information System (INIS)

    Falco, Maria Daniela; Fontanarosa, Davide; Miceli, Roberto; Carosi, Alessandra; Santoni, Riccardo; D'Andrea, Marco

    2011-01-01

    accurate, and its registration matrix can be easily translated into the TPS and a low dose is delivered to the patient during image acquisition. These results can help in designing imaging protocols for offline evaluations.

  16. Dual-source cardiac computed tomography angiography (CCTA) in the follow-up of cardiac transplant: comparison of image quality and radiation dose using three different imaging protocols

    International Nuclear Information System (INIS)

    Beitzke, D.; Berger-Kulemann, V.; Unterhumer, S.; Loewe, C.; Wolf, F.; Schoepf, V.; Spitzer, E.; Feuchtner, G.M.; Gyoengyoesi, M.; Uyanik-Uenal, K.; Zuckermann, A.

    2015-01-01

    To prospectively evaluate image quality (IQ) and radiation dose of dual-source cardiac computed tomography (CCTA) using different imaging protocols. CCTA was performed in 150 patients using the retrospective ECG-gated spiral technique (rECG) the prospective ECG-gated technique (pECG), or the prospective ECG-gated technique with systolic imaging and automated tube voltage selection (pECGsys). IQ was rated using a 16-segment coronary artery model. Techniques were compared for overall IQ, IQ of the large and the small coronary artery segments. Effective dose was used for comparison of radiation dose. Overall IQ and IQ of the large segments showed no differences between the groups. IQ analysis of the small segments showed lowered IQ in pECGsys compared to rECG (p = 0.02), but not to pECG (p = 0.6). Effective dose did not differ significantly between rECG and pECG (p = 0.13), but was significantly lower for pECGsys (p < 0.001 vs. rECG and pECG). Radiation dose of dual-source CCTA in heart transplant recipients is significantly reduced by using prospective systolic scanning and automated tube voltage selection, while overall IQ and IQ of the large coronary segments are maintained. IQ appears to be lower compared to retrospective techniques with regard to small coronary segments. (orig.)

  17. Dual-source cardiac computed tomography angiography (CCTA) in the follow-up of cardiac transplant: comparison of image quality and radiation dose using three different imaging protocols

    Energy Technology Data Exchange (ETDEWEB)

    Beitzke, D.; Berger-Kulemann, V.; Unterhumer, S.; Loewe, C.; Wolf, F. [Medical University Vienna, Department of Biomedical Imaging and Image Guided Therapy, Division of Cardiovascular and Interventional Radiology, Vienna (Austria); Schoepf, V. [Medical University Vienna, Department of Biomedical Imaging and Image Guided Therapy, Division of Neuroradiology and Musculoskeletal Radiology, Vienna (Austria); Spitzer, E. [Bern University Hospital, Department of Cardiology, Bern (Switzerland); Feuchtner, G.M. [Innsbruck Medical University, Department of Radiology II, Innsbruck (Austria); Gyoengyoesi, M. [Medical University Vienna, Department of Cardiology, Vienna (Austria); Uyanik-Uenal, K.; Zuckermann, A. [Medical University Vienna, Department of Cardiac Surgery, Vienna (Austria)

    2015-08-15

    To prospectively evaluate image quality (IQ) and radiation dose of dual-source cardiac computed tomography (CCTA) using different imaging protocols. CCTA was performed in 150 patients using the retrospective ECG-gated spiral technique (rECG) the prospective ECG-gated technique (pECG), or the prospective ECG-gated technique with systolic imaging and automated tube voltage selection (pECGsys). IQ was rated using a 16-segment coronary artery model. Techniques were compared for overall IQ, IQ of the large and the small coronary artery segments. Effective dose was used for comparison of radiation dose. Overall IQ and IQ of the large segments showed no differences between the groups. IQ analysis of the small segments showed lowered IQ in pECGsys compared to rECG (p = 0.02), but not to pECG (p = 0.6). Effective dose did not differ significantly between rECG and pECG (p = 0.13), but was significantly lower for pECGsys (p < 0.001 vs. rECG and pECG). Radiation dose of dual-source CCTA in heart transplant recipients is significantly reduced by using prospective systolic scanning and automated tube voltage selection, while overall IQ and IQ of the large coronary segments are maintained. IQ appears to be lower compared to retrospective techniques with regard to small coronary segments. (orig.)

  18. Cranial CT with 64-, 16-, 4- and single-slice CT systems-comparison of image quality and posterior fossa artifacts in routine brain imaging with standard protocols

    Energy Technology Data Exchange (ETDEWEB)

    Ertl-Wagner, Birgit; Eftimov, Lara; Becker, Christoph; Reiser, Maximilian [University of Munich, Grosshadern (Germany). Institute of Clinical Radiology; Blume, Jeffrey; Cormack, Jean [Brown University, Center for Statistical Sciences, Providence, RI (United States); Bruening, Roland; Brueckmann, Hartmut [University of Munich, Grosshadern (Germany). Department of Neuroradiology

    2008-08-15

    Posterior fossa artifacts constitute a characteristic limitation of cranial CT. To identify practical benefits and drawbacks of newer CT systems with reduced collimation in routine cranial imaging, we aimed to investigate image quality, posterior fossa artifacts and parenchymal delineation in non-enhanced CT (NECT) with 1-, 4-, 16- and 64-slice scanners using standard scan protocols. We prospectively enrolled 25 consecutive patients undergoing NECT on a 64-slice CT. Three groups with 25 patients having undergone NECT on 1-, 4- and 16-slice CT machines were matched regarding age and sex. Standard routine CT parameters were used on each CT system with helical acquisition in the posterior fossa; the parameters varied regarding collimation and radiation dose. Three blinded readers independently assessed the cases regarding image quality, infra- and supratentorial artifacts and delineation of brain parenchymal structures on a five-point ordinal scale. Reading orders were randomized. A proportional odds model that accounted for the correlated nature of the data was fit using generalized estimating equations. Posterior fossa artifacts were significantly reduced, and the delineation of infratentorial brain structures was significantly improved with the thinner collimation used for the newer CT systems (p<0.001). No significant differences were observed for midbrain structures (p>0.5). The thinner collimation available on modern CT systems leads to reduced posterior fossa artifacts and to a better delineation of brain parenchyma in the posterior fossa. (orig.)

  19. Multi-slice and dual-source CT in cardiac imaging. Principles - protocols - indications - outlook. 2. ed.

    International Nuclear Information System (INIS)

    Ohnesorge, B.M.; Flohr, T.G.; Becker, C.R.; Reiser, M.F.; Knez, A

    2007-01-01

    Cardiac diseases, and in particular coronary artery disease, are the leading cause of death and morbidity in industrialized countries. The development of non-invasive imaging techniques for the heart and the coronary arteries has been considered a key element in improving patient care. A breakthrough in cardiac imaging using CT occurred in 1998, with the introduction of multi-slice computed tomography (CT). Since then, amazing advances in performance have taken place with scanners that acquire up to 64 slices per rotation. This book discusses the state-of-the-art developments in multi-slice CT for cardiac imaging as well as those that can be anticipated in the future. It serves as a comprehensive work that covers all aspects of this technology, from the technical fundamentals and image evaluation all the way to clinical indications and protocol recommendations. This fully reworked second edition draws on the most recent clinical experience obtained with 16- and 64-slice CT scanners by world-leading experts from Europe and the United States. It also includes ''hands-on'' experience in the form of 10 representative clinical case studies, which are included on the accompanying CD. As a further highlight, the latest results of the very recently introduced dual-source CT, which may soon represent the CT technology of choice for cardiac applications, are presented. This book will not only convince the reader that multi-slice cardiac CT has arrived in clinical practice, it will also make a significant contribution to the education of radiologists, cardiologists, technologists, and physicists-whether newcomers, experienced users, or researchers. (orig.)

  20. Patterns of CMR measured longitudinal strain and its association with late gadolinium enhancement in patients with cardiac amyloidosis and its mimics.

    Science.gov (United States)

    Williams, Lynne K; Forero, Julian F; Popovic, Zoran B; Phelan, Dermot; Delgado, Diego; Rakowski, Harry; Wintersperger, Bernd J; Thavendiranathan, Paaladinesh

    2017-08-07

    Regional variability of longitudinal strain (LS) has been previously described with echocardiography in patients with cardiac amyloidosis (CA), however, the reason for this variability is not completely evident. We sought to describe regional patterns in LS using feature-tracking software applied to cardiovascular magnetic resonance (CMR) cine images in patients with CA, hypertrophic cardiomyopathy (HCM), and Anderson-Fabry's disease (AFD) and to relate these patterns to the distribution of late gadolinium enhancement (LGE). Patients with CA (n = 45) were compared to LV mass indexed matched patients with HCM (n = 19) and AFD (n = 19). Peak systolic LS measurements were obtained using Velocity Vector Imaging (VVI) software on CMR cine images. A relative regional LS ratio (RRSR) was calculated as the ratio of the average of the apical segmental LS divided by the sum of the average basal and mid-ventricular segmental LS. LGE was quantified for the basal, mid, and apical segments using a threshold of 5SD above remote myocardium. A regional LGE ratio was calculated similar to RRSR. Patients with CA had significantly had worse global LS (-15.7 ± 4.6%) than those with HCM (-18.0 ± 4.6%, p = 0.046) and AFD (-21.9 ± 5.1%, p < 0.001). The RRSR was higher in patients with CA (1.00 ± 0.31) than in AFD (0.79 ± 0.24; p = 0.018) but not HCM (0.84 ± 0.32; p = 0.114). In CA, a regional difference in LGE burden was noted, with lower LGE in the apex (31.5 ± 19.1%) compared to the mid (38.2 ± 19.0%) and basal (53.7 ± 22.7%; p < 0.001 for both) segments. The regional LGE ratio was not significantly different between patients with CA (0.33 ± 0.15) and AFD (0.47 ± 0.58; p = 0.14) but lower compared to those with HCM (0.72 ± 0.43; p < 0.0001). LGE percentage showed a significant impact on LS (p < 0.0001), with a 0.9% decrease in absolute LS for every 10% increase in LGE percentage. The presence of marked "relative apical sparing

  1. Risks to the fetus from diagnostic imaging during pregnancy: review and proposal of a clinical protocol

    International Nuclear Information System (INIS)

    Gomes, Mafalda; Matias, Alexandra; Macedo, Filipe

    2015-01-01

    Every day, medical practitioners face the dilemma of exposing pregnant or possibly pregnant patients to radiation from diagnostic examinations. Both doctors and patients often have questions about the risks of radiation. The most vulnerable period is between the 8th and 15th weeks of gestation. Deterministic effects like pregnancy loss, congenital malformations, growth retardation and neurobehavioral abnormalities have threshold doses above 100-200 mGy. The risk is considered negligible at 50 mGy and in reality no diagnostic examination exceeds this limit. The risk of carcinogenesis is slightly higher than in the general population. Intravenous iodinated contrast is discouraged, except in highly selected patients. Considering all the possible noxious effects of radiation exposure, measures to diminish radiation are essential and affect the fetal outcome. Nonionizing procedures should be considered whenever possible and every radiology center should have its own data analysis on fetal radiation exposure. In this review, we analyze existing literature on fetal risks due to radiation exposure, producing a clinical protocol to guide safe radiation use in a clinical setting. (orig.)

  2. Risks to the fetus from diagnostic imaging during pregnancy: review and proposal of a clinical protocol.

    Science.gov (United States)

    Gomes, Mafalda; Matias, Alexandra; Macedo, Filipe

    2015-12-01

    Every day, medical practitioners face the dilemma of exposing pregnant or possibly pregnant patients to radiation from diagnostic examinations. Both doctors and patients often have questions about the risks of radiation. The most vulnerable period is between the 8th and 15th weeks of gestation. Deterministic effects like pregnancy loss, congenital malformations, growth retardation and neurobehavioral abnormalities have threshold doses above 100-200 mGy. The risk is considered negligible at 50 mGy and in reality no diagnostic examination exceeds this limit. The risk of carcinogenesis is slightly higher than in the general population. Intravenous iodinated contrast is discouraged, except in highly selected patients. Considering all the possible noxious effects of radiation exposure, measures to diminish radiation are essential and affect the fetal outcome. Nonionizing procedures should be considered whenever possible and every radiology center should have its own data analysis on fetal radiation exposure. In this review, we analyze existing literature on fetal risks due to radiation exposure, producing a clinical protocol to guide safe radiation use in a clinical setting.

  3. Proposed protocol for imaging breast carcinoma patients treated with lumpectomy and radiation therapy

    International Nuclear Information System (INIS)

    Mendelson, E.B.; Bhagwanani, D.G.; Bohm-Velez, M.; Rishi, U.S.

    1989-01-01

    Alterations in conservatively treated breasts have been described and include masses (hematomas, seromas), spiculated densities, architectural distortion, increased breast density and edema, skin thickening, and calcifications. Misinterpretations of these findings might result in unnecessary biopsy or delayed diagnosis of tumor recurrence. Changes after lumpectomy and radiation therapy must be evaluated within a temporal context, best defined from a careful review of sequential follow-up studies. From a review of interval studies of 110 cases of conservatively treated breast cancer during a 4-year period, the chronology of findings after lumpectomy and radiation therapy was determined. Of particular importance is the evolution of changes at the lumpectomy site, which was the location of the six recurrences in our series, all developing 36--48 months after surgery. Based on the sequential findings that the authors observed as well s the reported frequency of tumor recurrence over time, the authors propose a protocol for follow-up mammography and offer indications for supplemental sonography in managing patients with conservatively treated breast cancer

  4. Risks to the fetus from diagnostic imaging during pregnancy: review and proposal of a clinical protocol

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Mafalda; Matias, Alexandra [University of Porto, Faculty of Medicine, Porto (Portugal); Macedo, Filipe [SMIC, Porto (Portugal)

    2015-12-15

    Every day, medical practitioners face the dilemma of exposing pregnant or possibly pregnant patients to radiation from diagnostic examinations. Both doctors and patients often have questions about the risks of radiation. The most vulnerable period is between the 8th and 15th weeks of gestation. Deterministic effects like pregnancy loss, congenital malformations, growth retardation and neurobehavioral abnormalities have threshold doses above 100-200 mGy. The risk is considered negligible at 50 mGy and in reality no diagnostic examination exceeds this limit. The risk of carcinogenesis is slightly higher than in the general population. Intravenous iodinated contrast is discouraged, except in highly selected patients. Considering all the possible noxious effects of radiation exposure, measures to diminish radiation are essential and affect the fetal outcome. Nonionizing procedures should be considered whenever possible and every radiology center should have its own data analysis on fetal radiation exposure. In this review, we analyze existing literature on fetal risks due to radiation exposure, producing a clinical protocol to guide safe radiation use in a clinical setting. (orig.)

  5. Using machine learning to speed up manual image annotation: application to a 3D imaging protocol for measuring single cell gene expression in the developing C. elegans embryo

    Directory of Open Access Journals (Sweden)

    Waterston Robert H

    2010-02-01

    Full Text Available Abstract Background Image analysis is an essential component in many biological experiments that study gene expression, cell cycle progression, and protein localization. A protocol for tracking the expression of individual C. elegans genes was developed that collects image samples of a developing embryo by 3-D time lapse microscopy. In this protocol, a program called StarryNite performs the automatic recognition of fluorescently labeled cells and traces their lineage. However, due to the amount of noise present in the data and due to the challenges introduced by increasing number of cells in later stages of development, this program is not error free. In the current version, the error correction (i.e., editing is performed manually using a graphical interface tool named AceTree, which is specifically developed for this task. For a single experiment, this manual annotation task takes several hours. Results In this paper, we reduce the time required to correct errors made by StarryNite. We target one of the most frequent error types (movements annotated as divisions and train a support vector machine (SVM classifier to decide whether a division call made by StarryNite is correct or not. We show, via cross-validation experiments on several benchmark data sets, that the SVM successfully identifies this type of error significantly. A new version of StarryNite that includes the trained SVM classifier is available at http://starrynite.sourceforge.net. Conclusions We demonstrate the utility of a machine learning approach to error annotation for StarryNite. In the process, we also provide some general methodologies for developing and validating a classifier with respect to a given pattern recognition task.

  6. Adherence to Imaging Protocol and Impact of Training on the Interpretation of CEA-Scan (arcitumomab) Imaging for colorectal Cancer

    International Nuclear Information System (INIS)

    Rubinstein, Michael; VanDaele, Paul; Wegener, William MD; Guardia, Miguel de la

    2004-01-01

    Purpose: To determine if imaging with acetobromo (immunoscintigraphy) is sensitive to technical and interpretative techniques that must be mastered in order to obtain reliable results. We studied the impact of training to reduce the learning curve. Methods: 1) Evaluate the performance of an experienced Nuclear Medicine Physicians (Team A) un-blinded with their initial series of patients, compared to the conclusions of Experts (Team B) blinded from any clinical information; 2) Training of Team A is by the expert team on image acquisition, processing and interpretation techniques as well as using all clinical information and anatomic studies for comparison; 3) Assess the performance of the Team A on a second series of patients. 4) Questionnaires were sent to 65 consecutive physicians trained by experts to determine if the learned techniques improved interpretation of immuno scintigrams. Results: Twenty three (23) patients with CRC were included, 13 pre and 10 for the post teaching phase with a total of 30 clinically confirmed lesions (pathologically proven or demonstrated on follow-up). The clinically confirmed lesions include: 8 primary, 12 pelvic recurrences and 10 metastatic sites. On the pre-teaching series, Team A correctly identified only 6/19 lesions (32%). On the post teaching series, Team A found 8/11 lesions (73%) including 4/5 pelvic recurrence (80%), all 3 primary lesions, and 1/3 metastasis which compares favorably to published results. To determine the effect of blinded reading of immuno scintigrams, Team B reviews the first 13 studies without any clinical information or CT for comparison. Team B found 10/19 lesions (53%) with 4 false positive. Questionnaires were mailed to 65 trained physicians (54 returned), 67% of responders found that training improved their results, 22% experienced mixed results and 11% did not notice any improvement. Conclusion: The lower than expected sensitivity by the blinded Expert Team confirms that the overall accuracy

  7. Evaluation of a chemical risk assessment method of South Korea for chemicals classified as carcinogenic, mutagenic or reprotoxic (CMR).

    Science.gov (United States)

    Kim, Min-Uk; Byeon, Sang-Hoon

    2017-12-12

    Chemicals were used in various fields by the development of industry and science and technology. The Chemical Hazard Risk Management (CHARM) was developed to assess the risk of chemicals in South Korea. In this study, we were to evaluate the CHARM model developed for the effective management of workplace chemicals. We used 59 carcinogenic, mutagenic or reprotoxic (CMR) materials, which are both the work environment measurement result and the usage information among the manufacturer data. The CHARM model determines the risk to human health using the exposure level (based on working environment measurements or a combination of the quantity used and chemical physical properties (e.g., fugacity and volatility)), hazard (using occupational exposure limit (OEL) or Risk phrases (R-phrases)/Hazard statements (H-statements) from the Material Safety Data Sheet (MSDS)). The risk level was lower when using the results of the work environment measurement than when applying the chemical quantity and physical properties in the exposure level evaluation method. It was evaluated as grade 4 for the CMR material in the hazard class determination. The risk assessment method by R-phrases was evaluated more conservatively than the risk assessment method by OEL. And the risk assessment method by H-statements was evaluated more conservatively than the risk assessment method by R-phrases. The CHARM model was gradually conservatively assessed as it proceeded in the next step without quantitative information for individual workplaces. The CHARM is expected to help identify the risk if the hazards and exposure levels of chemicals were identified in individual workplaces. For CMR substances, although CHARM is highly evaluated for hazards, the risk is assessed to be low if exposure levels are assessed low. When evaluating the risk of highly hazardous chemicals such as CMR substances, we believe the model should be adapted to be more conservative and classify these as higher risk. This work is

  8. Gated single-photon emission tomography imaging protocol to evaluate myocardial stunning after exercise

    International Nuclear Information System (INIS)

    Hashimoto, Jun; Kubo, Atsushi; Iwasaki, Ryuichiro; Iwanaga, Shiro; Mitamura, Hideo; Ogawa, Satoshi; Kosuda, Shigeru

    1999-01-01

    This study was designed to apply ECG-gating to stress myocardial perfusion single-photon emission tomography (SPET) for the evaluation of myocardial stunning after exercise. Technetium-99m sestamibi was selected as the perfusion agent and a rest/exercise 1-day protocol was employed. Fourteen patients without coronary stenosis and 33 patients with coronary stenosis were enrolled in the study. We carried out three data acquisitions with ECG-gating: a 15-min data acquisition starting 30 min after the rest injection (AC1), a 5-min acquisition starting 5 min after the stress injection (AC2) and a 15-min acquisition starting 20 min after the stress injection (AC3). Calculation of left ventricular ejection fraction (LVEF) values was performed by means of automatic determination of the endocardial surface for all gating intervals in the cardiac cycle. Measured global EF values in 14 patients without coronary stenosis were 52.3%±7.6% (AC1), 60.6%±8.9% (AC2) and 55.6%±5.6% (AC3), and those in 11 patients with severe ischaemia were 53.6%±8.0% (AC1), 45.6%±12.1% (AC2) and 49.7%±10.7%. The magnitude of the depression of post-stress LVEF relative to the rest LVEF correlated with the severity of ischaemia (r=0.594, P=0.002), and segments manifesting post-stress functional depression were associated with ischaemic segments showing reversible perfusion defects. Stress myocardial perfusion SPET with ECG-gating is a feasible method for the evaluation of myocardial stunning as well as exercise-induced ischaemia. (orig.)

  9. Reliability of diagnostic imaging techniques in suspected acute appendicitis: proposed diagnostic protocol

    International Nuclear Information System (INIS)

    Cura del, J. L.; Oleaga, L.; Grande, D.; Vela, A. C.; Ibanez, A. M.

    2001-01-01

    To study the utility of ultrasound and computed tomography (CT) in case of suspected appendicitis. To determine the diagnostic yield in terms of different clinical contexts and patient characteristics. to assess the costs and benefits of introducing these techniques and propose a protocol for their use. Negative appendectomies, complications and length of hospital stay in a group of 152 patients with suspected appendicitis who underwent ultrasound and CT were compared with those of 180 patients who underwent appendectomy during the same time period, but had not been selected for the first group: these patients costs for each group were calculated. In the first group, the diagnostic value of the clinical signs was also evaluated. The reliability of the clinical signs was limited, while the results with ultrasound and CT were excellent. The incidence of negative appendectomy was 9.6% in the study group and 12.2% in the control group. Moreover, there were fewer complications and a shorter hospital stay in the first group. Among men, however, the rate of negative appendectomy was lower in the control group. The cost of using ultrasound and CT in the management of appendicitis was only slightly higher than that of the control group. Although ultrasound and CT are not necessary in cases in which the probability of appendicitis is low or in men presenting clear clinical evidence, the use of these techniques is indicated in the remaining cases in which appendicitis is suspected. In children, ultrasound is the technique of choice. In all other patients, if negative results are obtained with one of the two techniques, the other should be performed. (Author) 49 refs

  10. Coronary artery calcification score by multislice computed tomography predicts the outcome of dobutamine cardiovascular magnetic resonance imaging

    International Nuclear Information System (INIS)

    Janssen, Caroline H.C.; Vliegenthart, Rozemarijn; Overbosch, Jelle; Oudkerk, Matthijs; Kuijpers, Dirkjan; Dijkman, Paul R.M. van; Zijlstra, Felix

    2005-01-01

    The aim of this study was to determine whether a coronary artery calcium (CAC) score of less than 11 can reliably rule out myocardial ischemia detected by dobutamine cardiovascular magnetic resonance imaging (CMR) in patients suspected of having myocardial ischemia. In 114 of 136 consecutive patients clinically suspected of myocardial ischemia with an inconclusive diagnosis of myocardial ischemia, dobutamine CMR was performed and the CAC score was determined. The CAC score was obtained by 16-row multidetector computed tomography (MDCT) and was calculated according to the method of Agatston. The CAC score and the results of the dobutamine CMR were correlated and the positive predictive value (PPV) and the negative predictive value (NPV) of the CAC score for dobutamine CMR were calculated. A total of 114 (87%) of the patients were eligible for this study. There was a significant correlation between the CAC score and dobutamine CMR (p<0.001). Patients with a CAC score of less than 11 showed no signs of inducible ischemia during dobutamine CMR. For a CAC score of less than 101, the NPV and the PPV of the CAC score for the outcome of dobutamine CMR were, respectively, 0.96 and 0.29. In patients with an inconclusive diagnosis of myocardial ischemia a MDCT CAC score of less than 11 reliably rules out myocardial ischemia detected by dobutamine CMR. (orig.)

  11. Coronary artery calcification score by multislice computed tomography predicts the outcome of dobutamine cardiovascular magnetic resonance imaging.

    Science.gov (United States)

    Janssen, Caroline H C; Kuijpers, Dirkjan; Vliegenthart, Rozemarijn; Overbosch, Jelle; van Dijkman, Paul R M; Zijlstra, Felix; Oudkerk, Matthijs

    2005-06-01

    The aim of this study was to determine whether a coronary artery calcium (CAC) score of less than 11 can reliably rule out myocardial ischemia detected by dobutamine cardiovascular magnetic resonance imaging (CMR) in patients suspected of having myocardial ischemia. In 114 of 136 consecutive patients clinically suspected of myocardial ischemia with an inconclusive diagnosis of myocardial ischemia, dobutamine CMR was performed and the CAC score was determined. The CAC score was obtained by 16-row multidetector compued tomography (MDCT) and was calculated according to the method of Agatston. The CAC score and the results of the dobutamine CMR were correlated and the positive predictive value (PPV) and the negative predictive value (NPV) of the CAC score for dobutamine CMR were calculated. A total of 114 (87%) of the patients were eligible for this study. There was a significant correlation between the CAC score and dobutamine CMR (p<0.001). Patients with a CAC score of less than 11 showed no signs of inducible ischemia during dobutamine CMR. For a CAC score of less than 101, the NPV and the PPV of the CAC score for the outcome of dobutamine CMR were, respectively, 0.96 and 0.29. In patients with an inconclusive diagnosis of myocardial ischemia a MDCT CAC score of less than 11 reliably rules out myocardial ischemia detected by dobutamine CMR.

  12. Coronary artery calcification score by multislice computed tomography predicts the outcome of dobutamine cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, Caroline H.C.; Vliegenthart, Rozemarijn; Overbosch, Jelle; Oudkerk, Matthijs [University Hospital Groningen, Department of Radiology, Groningen (Netherlands); Kuijpers, Dirkjan [University Hospital Groningen, Department of Radiology, Groningen (Netherlands); Bronovo Hospital, Department of Radiology, The Hague (Netherlands); Dijkman, Paul R.M. van [Bronovo Hospital, Department of Cardiology, The Hague (Netherlands); Zijlstra, Felix [University Hospital Groningen, Department of Cardiology, Groningen (Netherlands)

    2005-06-01

    The aim of this study was to determine whether a coronary artery calcium (CAC) score of less than 11 can reliably rule out myocardial ischemia detected by dobutamine cardiovascular magnetic resonance imaging (CMR) in patients suspected of having myocardial ischemia. In 114 of 136 consecutive patients clinically suspected of myocardial ischemia with an inconclusive diagnosis of myocardial ischemia, dobutamine CMR was performed and the CAC score was determined. The CAC score was obtained by 16-row multidetector computed tomography (MDCT) and was calculated according to the method of Agatston. The CAC score and the results of the dobutamine CMR were correlated and the positive predictive value (PPV) and the negative predictive value (NPV) of the CAC score for dobutamine CMR were calculated. A total of 114 (87%) of the patients were eligible for this study. There was a significant correlation between the CAC score and dobutamine CMR (p<0.001). Patients with a CAC score of less than 11 showed no signs of inducible ischemia during dobutamine CMR. For a CAC score of less than 101, the NPV and the PPV of the CAC score for the outcome of dobutamine CMR were, respectively, 0.96 and 0.29. In patients with an inconclusive diagnosis of myocardial ischemia a MDCT CAC score of less than 11 reliably rules out myocardial ischemia detected by dobutamine CMR. (orig.)

  13. Laser Doppler imaging as a tool in the burn wound treatment protocol

    OpenAIRE

    Venclauskiene, Algirda; Basevicius, Algidas; Zacharevskij, Ernest; Vaicekauskas, Vytautas; Rimdeika, Rytis; Lukosevicius, Saulius

    2014-01-01

    Introduction The main treatment of burns is early excision of injured tissues. Aim To compare two different methods of examination of burned patients: clinical burn depth examination (CDE) and laser Doppler imaging (LDI). Material and methods A prospective randomized study of 57 burn patients treated in 2009–2011 was carried out. The burned patients were randomized into a CDE group and an LDI group. The CDE and LDI scan were performed 72 h after injury, with the second and third CDE and LDI s...

  14. Importance of CMR within the Task Force Criteria for the diagnosis of ARVC in children and adolescents.

    Science.gov (United States)

    Etoom, Yousef; Govindapillai, Sindu; Hamilton, Robert; Manlhiot, Cedric; Yoo, Shi-Joon; Farhan, Maryam; Sarikouch, Samir; Peters, Brigitte; McCrindle, Brian W; Grosse-Wortmann, Lars

    2015-03-17

    Cardiac magnetic resonance (CMR) is a component of the revised Task Force Criteria (rTFC) for the diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC). However, its diagnostic value in a pediatric population is unknown. This study examined the contribution of CMR to diagnosing ARVC using the rTFC in a pediatric population. Clinical CMR studies of 142 pediatric patients evaluated for ARVC between 2005 and 2009 were reviewed. Patients were categorized into "definitive," "borderline," "possible," or "no" ARVC diagnostic groups based on the rTFC. The extent to which each element of the rTFC contributed to diagnosing ARVC was determined using a c-statistics model. A total of 23 (16%), 32 (23%), 37 (26%), and 50 (35%) patients had definite, borderline, possible, and no ARVC, respectively, applying the rTFC. The prevalence of regional wall motion abnormalities in these groups was 83%, 53%, 22%, and 16%, respectively (p important contributors to a diagnosis of ARVC in children, using the rTFC. Fatty infiltration and myocardial fibrosis provide limited value in children and adolescents. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  15. Cardiovascular magnetic resonance imaging of hypoplastic left heart syndrome in children

    International Nuclear Information System (INIS)

    Dillman, Jonathan R.; Hernandez, Ramiro J.; Dorfman, Adam L.; Attili, Anil K.; Agarwal, Prachi P.; Mueller, Gisela C.; Bell, Aaron

    2010-01-01

    Cardiovascular magnetic resonance imaging (CMR) plays an important complementary role to echocardiography and conventional angiography in the evaluation of hypoplastic left heart syndrome. This imaging modality is particularly useful for assessing cardiovascular postsurgical changes, extracardiac vascular anatomy, ventricular and valvular function, and a variety of complications. The purpose of this article is to provide a contemporary review of the role of CMR in the management of untreated and surgically palliated hypoplastic left heart syndrome in children. (orig.)

  16. Transcription factor VdCmr1 is required for pigment production, protection from UV irradiation, and regulates expression of melanin biosynthetic genes in Verticillium dahliae.

    Science.gov (United States)

    Wang, Yonglin; Hu, Xiaoping; Fang, Yulin; Anchieta, Amy; Goldman, Polly H; Hernandez, Gustavo; Klosterman, Steven J

    2018-04-01

    Verticillium dahliae is a soilborne fungus that causes vascular wilt diseases on numerous plant species worldwide. The production of darkly melanized microsclerotia is crucial in the disease cycle of V. dahliae, as these structures allow for long-term survival in soil. Previously, transcriptomic and genomic analysis identified a cluster of genes in V. dahliae that encodes some dihydroxynaphthalene (DHN) melanin biosynthetic pathway homologues found in related fungi. In this study, we explored the roles of cluster-specific transcription factor VdCmr1, as well as two other genes within the cluster encoding a polyketide synthase (VdPKS1) and a laccase (VdLac1), enzymes at initial and endpoint steps in DHN melanin production. The results revealed that VdCmr1 and VdPKS1 are required for melanin production, but neither is required for microsclerotia production. None of the three genes were required for pathogenesis on tobacco and lettuce. Exposure of ΔVdCmr1 and wild-type strains to UV irradiation, or to high temperature (40 °C), revealed an approx. 50 % reduction of survival in the ΔVdCmr1 strain, relative to the wild-type strain, in response to either condition. Expression profiles revealed that expression of some melanin biosynthetic genes are in part dependent on VdCmr1. Combined data indicate VdCmr1 is a key regulator of melanin biosynthesis, and that via regulation of melanogenesis, VdCmr1 affects survival of V. dahliae in response to abiotic threats. We conclude with a model showing regulation of VdCmr1 by a high osmolarity glycerol response (Hog)-type MAP kinase pathway.

  17. Three-Dimensional Volumetric Assessment of Diastolic Function by Cardiac Magnetic Resonance Imaging: The Multi-Ethnic Study of Atherosclerosis (MESA).

    Science.gov (United States)

    Nacif, Marcelo S; Almeida, Andre L C; Young, Alistair A; Cowan, Brett R; Armstrong, Anderson C; Yang, Eunice; Sibley, Christopher T; Hundley, W Gregory; Liu, Songtao; Lima, Joao Ac; Bluemke, David A

    2017-01-01

    Cardiac Magnetic Resonance is in need of a simple and robust method for diastolic function assessment that can be done with routine protocol sequences. To develop and validate a three-dimensional (3D) model-based volumetric assessment of diastolic function using cardiac magnetic resonance (CMR) imaging and compare the results obtained with the model with those obtained by echocardiography. The study participants provided written informed consent and were included if having undergone both echocardiography and cine steady-state free precession (SSFP) CMR on the same day. Guide points at the septal and lateral mitral annulus were used to define the early longitudinal relaxation rate (E'), while a time-volume curve from the 3D model was used to assess diastolic filling parameters. We determined the correlation between 3D CMR and echocardiography and the accuracy of CMR in classifying the diastolic function grade. The study included 102 subjects. The E/A ratio by CMR was positively associated with the E/A ratio by echocardiography (r = 0.71, p deslocamento do anel mitral lateral (p = 0,007), bem como a razão entre E/e' por Doppler e E/E' pela RMC (p = 0,01). A velocidade normalizada de pico de enchimento (EM) determinada pela RMC e o tempo de desaceleração (TD) foram capazes de predizer a disfunção diastólica (áreas sob a curva [AUCs] = 0,70 e 0,72, respectivamente). Além disso, a razão E/E' lateral mostrou boa utilidade para a identificação da disfunção diastólica (AUC = 0,80). No geral, a ecocardiografia e a RMC apresentaram excelente concordância interobservador e intraobservador (coeficiente de correlação intraclasse 0,72 - 0,97). Uma modelagem 3D de imagens padrões de cine RMC foi capaz de identificar os indivíduos do estudo com função diastólica reduzida e mostrou uma boa reprodutibilidade, sugerindo ter potencial na avaliação rotineira da função diastólica por RMC.

  18. Implementation of an image guided intensity-modulated protocol for post-prostatectomy radiotherapy: planning data and acute toxicity outcomes.

    Science.gov (United States)

    Chua, Benjamin; Min, Myo; Wood, Maree; Edwards, Sarah; Hoffmann, Matthew; Greenham, Stuart; Kovendy, Andrew; McKay, Michael J; Shakespeare, Thomas P

    2013-08-01

    There is substantial interest in implementation of image-guided intensity-modulated radiotherapy (IG-IMRT) in the post-prostatectomy setting. We describe our implementation of IG-IMRT, and examine how often published organ-at-risk (OAR) constraints were met. Furthermore, we evaluate the incidence of acute genitourinary and gastrointestinal toxicities when patients were treated according to our protocol. Patients were eligible if they received post-prostatectomy radiotherapy (PPRT). Planning data were collected prospectively, and toxicity assessments were collected before, during and after treatment. Seventy-five eligible patients received either 64 Gy (19%) or 66 Gy (81%) in a single phase to the prostate bed. Suggested rectal dose-constraints of V40Gy < 60% and V60Gy < 40% were met in 64 (85%) and 75 (100%) patients, respectively. IMRT-specific rectal dose-constraints of V40Gy < 35% and V65Gy < 17% were achieved in 5 (7%) and 57 (76%) of patients. Bladder dose-constraint (V50Gy < 50%) was met in 58 (77%) patients. Two patients (3%) experienced new grade 3 genitourinary toxicity and one patient (1%) experienced new grade 3 gastroinestinal toxicity. All grade 3 toxicities had improved by 3-month review. Overall deterioration in urinary and gastrointestinal symptoms occurred in 33 (44%) and 35 (47%) of patients respectively. We report on our implementation of PPRT which takes into account nationally adopted guidelines, with a margin reduction supported by use of daily image guidance. Non-IMRT OAR constraints were met in most cases. IMRT-specific constraints were less often achieved despite margin reductions, suggesting the need for review of guidelines. Severe toxicity was rare, and most patients did not experience deterioration in urinary or bowel function attributable to radiotherapy. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

  19. Cumulative effective dose and cancer risk for pediatric population in repetitive full spine follow-up imaging: How micro dose is the EOS microdose protocol?

    Science.gov (United States)

    Law, Martin; Ma, Wang-Kei; Lau, Damian; Cheung, Kenneth; Ip, Janice; Yip, Lawrance; Lam, Wendy

    2018-04-01

    To evaluate and to obtain analytic formulation for the calculation of the effective dose and associated cancer risk using the EOS microdose protocol for scoliotic pediatric patients undergoing full spine imaging at different age of exposure; to demonstrate the microdose protocol capable of delivering lesser radiation dose and hence of further reducing cancer risk induction when compared with the EOS low dose protocol; to obtain cumulative effective dose and cancer risk for both genders scoliotic pediatrics of US and Hong Kong population using the microdose protocol. Organ absorbed doses of full spine exposed scoliotic pediatric patients have been simulated with the use of EOS microdose protocol imaging parameters input to the Monte Carlo software PCXMC. Gender and age specific effective dose has been calculated with the simulated organ absorbed dose using the ICRP-103 approach. The associated radiation induced cancer risk, expressed as lifetime attributable risk (LAR), has been estimated according to the method introduced in the Biological Effects of Ionizing Radiation VII report. Values of LAR have been estimated for scoliotic patients exposed repetitively during their follow up period at different age for US and Hong Kong population. The effective doses of full spine imaging with simultaneous posteroanterior and lateral projection for patients exposed at the age between 5 and 18 years using the EOS microdose protocol have been calculated within the range of 2.54-14.75 μSv. The corresponding LAR for US and Hong Kong population was ranged between 0.04 × 10 -6 and 0.84 × 10 -6 . Cumulative effective dose and cancer risk during follow-up period can be estimated using the results and are of information to patients and their parents. With the use of computer simulation and analytic formulation, we obtained the cumulative effective dose and cancer risk at any age of exposure for pediatric patients of US and Hong Kong population undergoing repetitive

  20. Effectiveness of a Rapid Lumbar Spine MRI Protocol Using 3D T2-Weighted SPACE Imaging Versus a Standard Protocol for Evaluation of Degenerative Changes of the Lumbar Spine.

    Science.gov (United States)

    Sayah, Anousheh; Jay, Ann K; Toaff, Jacob S; Makariou, Erini V; Berkowitz, Frank

    2016-09-01

    Reducing lumbar spine MRI scanning time while retaining diagnostic accuracy can benefit patients and reduce health care costs. This study compares the effectiveness of a rapid lumbar MRI protocol using 3D T2-weighted sampling perfection with application-optimized contrast with different flip-angle evolutions (SPACE) sequences with a standard MRI protocol for evaluation of lumbar spondylosis. Two hundred fifty consecutive unenhanced lumbar MRI examinations performed at 1.5 T were retrospectively reviewed. Full, rapid, and complete versions of each examination were interpreted for spondylotic changes at each lumbar level, including herniations and neural compromise. The full examination consisted of sagittal T1-weighted, T2-weighted turbo spin-echo (TSE), and STIR sequences; and axial T1- and T2-weighted TSE sequences (time, 18 minutes 40 seconds). The rapid examination consisted of sagittal T1- and T2-weighted SPACE sequences, with axial SPACE reformations (time, 8 minutes 46 seconds). The complete examination consisted of the full examination plus the T2-weighted SPACE sequence. Sensitivities and specificities of the full and rapid examinations were calculated using the complete study as the reference standard. The rapid and full studies had sensitivities of 76.0% and 69.3%, with specificities of 97.2% and 97.9%, respectively, for all degenerative processes. Rapid and full sensitivities were 68.7% and 66.3% for disk herniation, 85.2% and 81.5% for canal compromise, 82.9% and 69.1% for lateral recess compromise, and 76.9% and 69.7% for foraminal compromise, respectively. Isotropic SPACE T2-weighted imaging provides high-quality imaging of lumbar spondylosis, with multiplanar reformatting capability. Our SPACE-based rapid protocol had sensitivities and specificities for herniations and neural compromise comparable to those of the protocol without SPACE. This protocol fits within a 15-minute slot, potentially reducing costs and discomfort for a large subgroup of

  1. A no-key-exchange secure image sharing scheme based on Shamir's three-pass cryptography protocol and the multiple-parameter fractional Fourier transform.

    Science.gov (United States)

    Lang, Jun

    2012-01-30

    In this paper, we propose a novel secure image sharing scheme based on Shamir's three-pass protocol and the multiple-parameter fractional Fourier transform (MPFRFT), which can safely exchange information with no advance distribution of either secret keys or public keys between users. The image is encrypted directly by the MPFRFT spectrum without the use of phase keys, and information can be shared by transmitting the encrypted image (or message) three times between users. Numerical simulation results are given to verify the performance of the proposed algorithm.

  2. Postmortem cardiovascular magnetic resonance imaging in fetuses and children: a masked comparison study with conventional autopsy.

    Science.gov (United States)

    Taylor, Andrew M; Sebire, Neil J; Ashworth, Michael T; Schievano, Silvia; Scott, Rosemary J; Wade, Angie; Chitty, Lyn S; Robertson, Nikki; Thayyil, Sudhin

    2014-05-13

    Perinatal and pediatric autopsies have declined worldwide in the past decade. We compared the diagnostic accuracy of postmortem, cardiovascular magnetic resonance (CMR) imaging with conventional autopsy and histopathology assessment in fetuses and children. We performed postmortem magnetic resonance imaging in 400 fetuses and children, using a 1.5-T Siemens Avanto magnetic resonance scanner before conventional autopsy. A pediatric CMR imager reported the CMR images, masked to autopsy information. The pathologists were masked to the information from CMR images. The institutional research ethics committee approved the study, and parental consent was obtained. Assuming a diagnostic accuracy of 50%, 400 cases were required for a 5% precision of estimate. Three cases were excluded from analysis, 2 with no conventional autopsy performed and 1 with insufficient CMR sequences performed. Thirty-eight CMR data sets were nondiagnostic (37 in fetuses ≤24 weeks; 1 in a fetus >24 weeks). In the remaining 359 cases, 44 cardiac abnormalities were noted at autopsy. Overall sensitivity and specificity (95% confidence interval) of CMR was 72.7% (58.2-83.7%) and 96.2% (93.5-97.8%) for detecting any cardiac pathology, with positive and negative predictive values of 72.7% (58.2-83.7%) and 96.2% (93.5-97.8%), respectively. Higher sensitivity of 92.6% (76.6-97.9%), specificity of 99.1% (97.4-99.7%), positive predictive value of 89.3% (72.8-96.3%), and negative predictive value of 99.4% (97.8-99.8%) were seen for major structural heart disease. Postmortem CMR imaging may be a useful alternative to conventional cardiac autopsy in fetuses and children for detecting cardiac abnormalities. http://www.clinicaltrials.gov. Unique identifier: NCT01417962.

  3. Implementation of an image guided intensity-modulated protocol for post-prostatectomy radiotherapy: planning data and acute toxicity outcomes

    International Nuclear Information System (INIS)

    Chua, Benjamin; Min, Myo; Wood, Maree; Edwards, Sarah; Hoffmann, Matthew; Greenham, Stuart; Kovendy, Andrew; McKay, Michael J.; Shakespeare, Thomas P.

    2013-01-01

    There is substantial interest in implementation of image-guided intensity-modulated radiotherapy (IG-IMRT) in the post-prostatectomy setting. We describe our implementation of IG-IMRT, and examine how often published organ-at-risk (OAR) constraints were met. Furthermore, we evaluate the incidence of acute genitourinary and gastrointestinal toxicities when patients were treated according to our protocol. Patients were eligible if they received post-prostatectomy radiotherapy (PPRT). Planning data were collected prospectively, and toxicity assessments were collected before, during and after treatment. Seventy-five eligible patients received either 64Gy (19%) or 66Gy (81%) in a single phase to the prostate bed. Suggested rectal dose-constraints of V40Gy<60% and V60Gy<40% were met in 64 (85%) and 75 (100%) patients, respectively. IMRT-specific rectal dose-constraints of V40Gy<35% and V65Gy<17% were achieved in 5 (7%) and 57 (76%) of patients. Bladder dose-constraint (V50Gy<50%) was met in 58 (77%) patients. Two patients (3%) experienced new grade 3 genitourinary toxicity and one patient (1%) experienced new grade 3 gastrointestinal toxicity. All grade 3 toxicities had improved by 3-month review. Overall deterioration in urinary and gastrointestinal symptoms occurred in 33 (44%) and 35 (47%) of patients respectively. We report on our implementation of PPRT which takes into account nationally adopted guidelines, with a margin reduction supported by use of daily image guidance. Non-IMRT OAR constraints were met in most cases. IMRT-specific constraints were less often achieved despite margin reductions, suggesting the need for review of guidelines. Severe toxicity was rare, and most patients did not experience deterioration in urinary or bowel function attributable to radiotherapy.

  4. Troponin-positive chest pain with unobstructed coronary arteries: incremental diagnostic value of cardiovascular magnetic resonance imaging.

    Science.gov (United States)

    Pathik, Bhupesh; Raman, Betty; Mohd Amin, Nor Hanim; Mahadavan, Devan; Rajendran, Sharmalar; McGavigan, Andrew D; Grover, Suchi; Smith, Emma; Mazhar, Jawad; Bridgman, Cameron; Ganesan, Anand N; Selvanayagam, Joseph B

    2016-10-01

    Troponin-positive chest pain patients with unobstructed coronaries represent a clinical dilemma. Cardiovascular magnetic resonance (CMR) imaging has an increasingly prominent role in the assessment of these patients; however, its utility in addition to expert clinical judgement is unclear. We sought to determine the incremental diagnostic value of CMR and the heterogeneity in diagnoses by experienced cardiologists when presented with blinded clinical and investigative data in this population. A total of 125 consecutive patients presenting to a tertiary centre between 2010 and 2014 with cardiac chest pain, elevated troponin (>29 ng/L), and unobstructed coronaries were enrolled and underwent CMR. A panel of three experienced cardiologists unaware of the CMR diagnosis and blinded to each other's assessment provided a diagnosis based on clinical and investigative findings. A consensus panel diagnosis was defined as two or more cardiologists sharing the same clinical diagnosis. Findings were classified into acute myocarditis, Takotsubo cardiomyopathy, acute myocardial infarction (AMI), or indeterminate. CMR provided a diagnosis in 87% of patients. Consensus panel diagnosis and CMR were concordant in 65/125 (52%) patients. There was an only moderate level of agreement between the three cardiologists (k = 0.47, P < 0.05) and a poor level of agreement between the consensus panel and CMR (k = 0.38, P < 0.05) with the most disagreement seen in patients with AMI diagnosed on CMR. The clinical diagnosis of patients with non-obstructive coronaries and positive troponin remains a challenge. The concordance between CMR and clinical diagnosis is poor. CMR provides a diagnosis in majority of these patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  5. Imaging of congenital heart disease in adults: choice of modalities.

    Science.gov (United States)

    Orwat, Stefan; Diller, Gerhard-Paul; Baumgartner, Helmut

    2014-01-01

    Major advances in noninvasive imaging of adult congenital heart disease have been accomplished. These tools play now a key role in comprehensive diagnostic work-up, decision for intervention, evaluation for the suitability of specific therapeutic options, monitoring of interventions and regular follow-up. Besides echocardiography, magnetic resonance (CMR) and computed tomography (CT) have gained particular importance. The choice of imaging modality has thus become a critical issue. This review summarizes strengths and limitations of the different imaging modalities and how they may be used in a complementary fashion. Echocardiography obviously remains the workhorse of imaging routinely used in all patients. However, in complex disease and after surgery echocardiography alone frequently remains insufficient. CMR is particularly useful in this setting and allows reproducible and accurate quantification of ventricular function and comprehensive assessment of cardiac anatomy, aorta, pulmonary arteries and venous return including complex flow measurements. CT is preferred when CMR is contraindicated, when superior spatial resolution is required or when "metallic" artefacts limit CMR imaging. In conclusion, the use of currently available imaging modalities in adult congenital heart disease needs to be complementary. Echocardiography remains the basis tool, CMR and CT should be added considering specific open questions and the ability to answer them, availability and economic issues.

  6. Myocardial area at risk after ST-elevation myocardial infarction measured with the late gadolinium enhancement after scar remodeling and T2-weighted cardiac magnetic resonance imaging

    DEFF Research Database (Denmark)

    Lønborg, Jacob; Engstrøm, Thomas; Mathiasen, Anders B

    2011-01-01

    To evaluate the myocardial area at risk (AAR) measured by the endocardial surface area (ESA) method on late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) when applied after scar remodeling (3 months after index infarction) compared to T2-weighted CMR imaging. One hundred...... and sixty nine patients with ST-elevation myocardial infarction, treated with primary percutaneous coronary intervention, underwent one CMR within 1 week after index treatment to determine the AAR with T2-weighted imaging and a second scan 3 months after to measure AAR with the ESA method...

  7. Myocardial area at risk after ST-elevation myocardial infarction measured with the late gadolinium enhancement after scar remodeling and T2-weighted cardiac magnetic resonance imaging

    DEFF Research Database (Denmark)

    Lønborg, Jacob; Engstrøm, Thomas; Mathiasen, Anders B

    2012-01-01

    To evaluate the myocardial area at risk (AAR) measured by the endocardial surface area (ESA) method on late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) when applied after scar remodeling (3 months after index infarction) compared to T2-weighted CMR imaging. One hundred...... and sixty nine patients with ST-elevation myocardial infarction, treated with primary percutaneous coronary intervention, underwent one CMR within 1 week after index treatment to determine the AAR with T2-weighted imaging and a second scan 3 months after to measure AAR with the ESA method...

  8. Imaging focal and interstitial fibrosis with cardiovascular magnetic resonance in athletes with left ventricular hypertrophy: implications for sporting participation.

    LENUS (Irish Health Repository)

    Waterhouse, Deirdre F

    2012-11-01

    Long-term high-intensity physical activity is associated with morphological changes, termed as the \\'athlete\\'s heart\\'. The differentiation of physiological cardiac adaptive changes in response to high-level exercise from pathological changes consistent with an inherited cardiomyopathy is imperative. Cardiovascular magnetic resonance (CMR) imaging allows definition of abnormal processes occurring at the tissue level, including, importantly, myocardial fibrosis. It is therefore vital in accurately making this differentiation. In this review, we will review the role of CMR imaging of fibrosis, and detail CMR characterisation of myocardial fibrosis in various cardiomyopathies, and the implications of fibrosis. Additionally, we will outline advances in imaging fibrosis, in particular T1 mapping. Finally we will address the role of CMR in pre-participation screening.

  9. The tight binding model study of the role of anisotropic AFM spin ordering in the charge ordered CMR manganites

    Science.gov (United States)

    Kar, J. K.; Panda, Saswati; Rout, G. C.

    2017-05-01

    We propose here a tight binding model study of the interplay between charge and spin orderings in the CMR manganites taking anisotropic effect due to electron hoppings and spin exchanges. The Hamiltonian consists of the kinetic energies of eg and t2g electrons of manganese ion. It further includes double exchange and Heisenberg interactions. The charge density wave interaction (CDW) describes an extra mechanism for the insulating character of the system. The CDW gap and spin parameters are calculated using Zubarev's Green's function technique and computed self-consistently. The results are reported in this communication.

  10. 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.

  11. Extracardiac findings detected by cardiac magnetic resonance imaging

    International Nuclear Information System (INIS)

    Wyttenbach, Rolf; Medioni, Nathalie; Santini, Paolo; Vock, Peter; Szucs-Farkas, Zsolt

    2012-01-01

    To determine the prevalence and importance of extracardiac findings (ECF) in patients undergoing clinical CMR and to test the hypothesis that the original CMR reading focusing on the heart may underestimate extracardiac abnormalities. 401 consecutive patients (mean age 53 years) underwent CMR at 1.5 T. Main indications were ischaemic heart disease (n = 183) and cardiomyopathy (n = 164). All CMR sequences, including scout images, were reviewed with specific attention to ECF in a second reading by the same radiologist who performed the first clinical reading. Potentially significant findings were defined as abnormalities requiring additional clinical or radiological follow-up. 250 incidental ECF were detected, of which 84 (34%) had potentially significant ECF including bronchial carcinoma (n = 1), lung consolidation (n = 7) and abdominal abnormalities. In 166 CMR studies (41%) non-significant ECF were detected. The number of ECF identified at second versus first reading was higher for significant (84 vs. 47) and non-significant (166 vs. 36) findings (P < 0.00001). About one fifth of patients undergoing CMR were found to have potentially significant ECF requiring additional work-up. The second dedicated reading detected significantly more ECF compared with the first clinical reading emphasising the importance of active search for extracardiac abnormalities when evaluating CMR studies. circle Many patients undergoing cardiac MR have significant extracardiac findings (ECF) circle These impact on management and require additional work-up. circle Wide review of scout and cine sequences will detect most ECFs. circle Education of radiologists is important to identify ECFs on CMR studies. (orig.)

  12. SU-F-I-46: Optimizing Dose Reduction in Adult Head CT Protocols While Maintaining Image Quality in Postmortem Head Scans

    International Nuclear Information System (INIS)

    Lipnharski, I; Carranza, C; Quails, N; Correa, N; Rajderkar, D; Bennett, J; Rill, L; Arreola, M

    2016-01-01

    Purpose: To optimize adult head CT protocol by reducing dose to an appropriate level while providing CT images of diagnostic quality. Methods: Five cadavers were scanned from the skull base to the vertex using a routine adult head CT protocol (120 kVp, 270 mA, 0.75 s rotation, 0.5 mm × 32 detectors, 70.8 mGy CTDIvol) followed by seven reduced-dose protocols with varying combinations of reduced tube current, reduced rotation time, and increased detectors with CTDIvol ranging from 38.2 to 65.6 mGy. Organ doses were directly measured with 21 OSL dosimeters placed on the surface and implanted in the head by a neurosurgeon. Two neuroradiologists assessed grey-white matter differentiation, fluid space, ventricular size, midline shift, brain mass, edema, ischemia, and skull fractures on a three point scale: (1) Unacceptable, (2) Borderline Acceptable, and (3) Acceptable. Results: For the standard scan, doses to the skin, lens of the eye, salivary glands, thyroid, and brain were 37.55 mGy, 49.65 mGy, 40.67 mGy, 4.63 mGy, and 27.33 mGy, respectively. Two cadavers had cerebral edema due to changing dynamics of postmortem effects, causing the grey-white matter differentiation to appear less distinct. Two cadavers with preserved grey-white matter received acceptable scores for all image quality features for the protocol with a CTDIvol of 57.3 mGy, allowing organ dose savings ranging from 34% to 45%. One cadaver allowed for greater dose reduction for the protocol with a CTDIvol of 42 mGy. Conclusion: Efforts to optimize scan protocol should consider both dose and clinical image quality. This is made possible with postmortem subjects, whose brains are similar to patients, allowing for an investigation of ideal scan parameters. Radiologists at our institution accepted scan protocols acquired with lower scan parameters, with CTDIvol values closer to the American College of Radiology’s (ACR) Achievable Dose level of 57 mGy.

  13. SU-F-I-46: Optimizing Dose Reduction in Adult Head CT Protocols While Maintaining Image Quality in Postmortem Head Scans

    Energy Technology Data Exchange (ETDEWEB)

    Lipnharski, I; Carranza, C; Quails, N; Correa, N; Rajderkar, D; Bennett, J; Rill, L; Arreola, M [University of Florida, Gainesville, FL (United States)

    2016-06-15

    Purpose: To optimize adult head CT protocol by reducing dose to an appropriate level while providing CT images of diagnostic quality. Methods: Five cadavers were scanned from the skull base to the vertex using a routine adult head CT protocol (120 kVp, 270 mA, 0.75 s rotation, 0.5 mm × 32 detectors, 70.8 mGy CTDIvol) followed by seven reduced-dose protocols with varying combinations of reduced tube current, reduced rotation time, and increased detectors with CTDIvol ranging from 38.2 to 65.6 mGy. Organ doses were directly measured with 21 OSL dosimeters placed on the surface and implanted in the head by a neurosurgeon. Two neuroradiologists assessed grey-white matter differentiation, fluid space, ventricular size, midline shift, brain mass, edema, ischemia, and skull fractures on a three point scale: (1) Unacceptable, (2) Borderline Acceptable, and (3) Acceptable. Results: For the standard scan, doses to the skin, lens of the eye, salivary glands, thyroid, and brain were 37.55 mGy, 49.65 mGy, 40.67 mGy, 4.63 mGy, and 27.33 mGy, respectively. Two cadavers had cerebral edema due to changing dynamics of postmortem effects, causing the grey-white matter differentiation to appear less distinct. Two cadavers with preserved grey-white matter received acceptable scores for all image quality features for the protocol with a CTDIvol of 57.3 mGy, allowing organ dose savings ranging from 34% to 45%. One cadaver allowed for greater dose reduction for the protocol with a CTDIvol of 42 mGy. Conclusion: Efforts to optimize scan protocol should consider both dose and clinical image quality. This is made possible with postmortem subjects, whose brains are similar to patients, allowing for an investigation of ideal scan parameters. Radiologists at our institution accepted scan protocols acquired with lower scan parameters, with CTDIvol values closer to the American College of Radiology’s (ACR) Achievable Dose level of 57 mGy.

  14. Clinical advances in cardiovascular magnetic resonace imaging and angiography

    NARCIS (Netherlands)

    Bosch, van den H.C.M.

    2018-01-01

    Cardiovascular magnetic resonance imaging is an important noninvasive imaging modality for the diagnosis, clinical work‐up and treatment planning in patients suspected for a wide range of cardiovascular pathology. CMR imaging is accurate and reliable, and provides invaluable information to evaluate

  15. A combined static-dynamic single-dose imaging protocol to compare quantitative dynamic SPECT with static conventional SPECT.

    Science.gov (United States)

    Sciammarella, Maria; Shrestha, Uttam M; Seo, Youngho; Gullberg, Grant T; Botvinick, Elias H

    2017-08-03

    SPECT myocardial perfusion imaging (MPI) is a clinical mainstay that is typically performed with static imaging protocols and visually or semi-quantitatively assessed for perfusion defects based upon the relative intensity of myocardial regions. Dynamic cardiac SPECT presents a new imaging technique based on time-varying information of radiotracer distribution, which permits the evaluation of regional myocardial blood flow (MBF) and coronary flow reserve (CFR). In this work, a preliminary feasibility study was conducted in a small patient sample designed to implement a unique combined static-dynamic single-dose one-day visit imaging protocol to compare quantitative dynamic SPECT with static conventional SPECT for improving the diagnosis of coronary artery disease (CAD). Fifteen patients (11 males, four females, mean age 71 ± 9 years) were enrolled for a combined dynamic and static SPECT (Infinia Hawkeye 4, GE Healthcare) imaging protocol with a single dose of 99m Tc-tetrofosmin administered at rest and a single dose administered at stress in a one-day visit. Out of 15 patients, eleven had selective coronary angiography (SCA), 8 within 6 months and the rest within 24 months of SPECT imaging, without intervening symptoms or interventions. The extent and severity of perfusion defects in each myocardial region was graded visually. Dynamically acquired data were also used to estimate the MBF and CFR. Both visually graded images and estimated CFR were tested against SCA as a reference to evaluate the validity of the methods. Overall, conventional static SPECT was normal in ten patients and abnormal in five patients, dynamic SPECT was normal in 12 patients and abnormal in three patients, and CFR from dynamic SPECT was normal in nine patients and abnormal in six patients. Among those 11 patients with SCA, conventional SPECT was normal in 5, 3 with documented CAD on SCA with an overall accuracy of 64%, sensitivity of 40% and specificity of 83%. Dynamic SPECT image

  16. Functional Magnetic Resonance Imaging Evaluation of Auricular Percutaneous Electrical Neural Field Stimulation for Fibromyalgia: Protocol for a Feasibility Study.

    Science.gov (United States)

    Gebre, Melat; Woodbury, Anna; Napadow, Vitaly; Krishnamurthy, Venkatagiri; Krishnamurthy, Lisa C; Sniecinski, Roman; Crosson, Bruce

    2018-02-06

    patient comorbidities and preferences, prescribed by a pain management practitioner. The PENFS group will include the above therapies in addition to the PENFS treatments. The PENFS subject group will have the Neuro-Stim System placed on the ear for 5 days then removed and replaced once per week for 4 weeks. The primary outcome will be resting functional magnetic resonance imaging connectivity between DMN and insula, which will also be correlated with pain relief and functional improvements. This connectivity will be analyzed utilizing functional connectivity magnetic resonance imaging (fcMRI) and will be compared with patient-reported analgesic improvements as indicated by the DVPRS and patient-reported analgesic medication consumption. Pain and function will be further evaluated using Patient-Reported Outcomes Measurement Information System measures and measures describing a person's functional status from Activity and Participation section of the International Classification of Functioning Disability and Health. This trial has been funded by the Veterans Health Administration Program Office. This study attained approval by the Emory University/Veterans Affairs (VA) institutional review board and VA Research & Development committee. Institutional review board expedited approval was granted on 2/7/17 (IRB00092224). The study start date is 6/1/17 and estimated completion date is 5/31/20. The recruitment started in June 2017. This is a feasibility study that is meant to demonstrate the practicality of using fcMRI to study the neural correlates of PENFS outcomes and provide information regarding power calculations in order to design and execute a larger randomized controlled clinical trial to determine the efficacy of PENFS for improving pain and function. ClinicalTrials.gov NCT03008837; https://clinicaltrials.gov/ct2/show/NCT03008837 (Archived by WebCite at http://www.webcitation.org/6wrY3NmaQ). ©Melat Gebre, Anna Woodbury, Vitaly Napadow, Venkatagiri Krishnamurthy, Lisa C

  17. Stress-first protocol for myocardial perfusion SPECT imaging with semiconductor cameras: high diagnostic performances with significant reduction in patient radiation doses

    International Nuclear Information System (INIS)

    Perrin, Mathieu; Claudin, Marine; Veran, Nicolas; Morel, Olivier; Besseau, Cyril; Boutley, Henri; Djaballah, Wassila; Poussier, Sylvain; Verger, Antoine; Moulin, Frederic; Imbert, Laetitia; Karcher, Gilles; Marie, Pierre-Yves

    2015-01-01

    Effective doses of 14 mSv or higher are currently being attained in patients having stress and rest myocardial perfusion imaging (MPI) single photon emission computed tomography (SPECT) performed on the same day with conventional protocols. This study aimed to assess the actual reduction in effective doses as well as diagnostic performances for MPI routinely planned with: (1) high-sensitivity cadmium zinc telluride (CZT) cameras, (2) very low injected activities and (3) a stress-first protocol where the normality of stress images may lead to avoiding rest imaging. During a 1-year period, 2,845 patients had MPI on a CZT camera, a single-day stress-first protocol and low injected activities (120 MBq of 99m Tc-sestamibi at stress for 75 kg body weight and threefold higher at rest). The ability to detect > 50 % coronary stenosis was assessed in a subgroup of 149 patients who also had coronary angiography, while the normalcy rate was assessed in a subgroup of 128 patients with a low pretest likelihood of coronary artery disease (<10 %). Overall, 33 % of patients had abnormal MPI of which 34 % were women and 34 % were obese. The mean effective doses and the percentage of exams involving only stress images were: (1) 3.53 ± 2.10 mSv and 37 % in the overall population, (2) 4.83 ± 1.56 mSv and 5 % in the subgroup with angiography and (3) 1.96 ± 1.52 mSv and 71 % in the low-probability subgroup. Sensitivity and global accuracy for identifying the 106 patients with coronary stenosis were 88 and 80 %, respectively, while the normalcy rate was 97 %. When planned with a low-dose stress-first protocol on a CZT camera, MPI provides high diagnostic performances and a dramatic reduction in patient radiation doses. This reduction is even greater in low-risk subgroups with high rates of normal stress images, thus allowing the mean radiation dose to be balanced against cardiac risk in targeted populations. (orig.)

  18. A protocol for patients with cardiovascular implantable devices undergoing magnetic resonance imaging (MRI): should defibrillation threshold testing be performed post-(MRI).

    Science.gov (United States)

    Burke, Peter Thomas; Ghanbari, Hamid; Alexander, Patrick B; Shaw, Michael K; Daccarett, Marcos; Machado, Christian

    2010-06-01

    Magnetic resonance imaging (MRI) in patients with Cardiovascular Implantable Electronic Devices (CIED) has not been approved by the Food and Drug Administration. Recent data suggests MRI as a relative rather than absolute contraindication in CIED patients. Recently, the American Heart Association has recommended defibrillation threshold testing (DFTT) in implantable cardioverter defibrillator (ICD) patients undergoing MRI. We evaluated the feasibility and safety of a protocol for MRI in CIED patients, incorporating the new recommendations on DFTT. Consecutive patients with CIED undergoing MRI were included. The protocol consisted of continuous monitoring during imaging, device interrogation pre- and post-MRI, reprogramming of the pacemaker to an asynchronous mode in pacemaker-dependent (PMD) patients and a non-tracking/sensing mode for non-PMD patients. All tachyarrhythmia therapies were disabled. Devices were interrogated for lead impedance, battery life, pacing, and sensing thresholds. All patients with ICD underwent DFTT/defibrillator safety margin testing (DSMT) post-MRI. A total of 92 MRI's at 1.5 Tesla were performed in 38 patients. A total of 13 PMD patients, ten ICD patients, four cardiac resynchronization therapy with defibrillator (CRT-D) patients, and 11 non-PMD patients were scanned from four major manufacturers. No device circuitry damage, programming alterations, inappropriate shocks, failure to pace, or changes in sensing, pacing, or defibrillator thresholds were found on single or multiple MRI sessions. Our protocol for MRI in CIED patients appears safe, feasible, and reproducible. This is irrespective of the type of CIED, pacemaker dependancy or multiple 24-h scanning sessions. Our protocol addresses early detection of potential complications and establishes a response system for potential device-related complications. Our observation suggests that routine DFTT/DSMT post-MRI may not be necessary.

  19. Development of a research protocol for neurological disease using ultrasound and photoacoustic imaging; Desenvolvimento de um protocolo de investigacao de doencas neurologicas utilizando imagens de ultrassonografia e fotoacustica

    Energy Technology Data Exchange (ETDEWEB)

    Sampaio, D.R.T; Carneiro, A.A.O.; Pavan, T.Z. [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Departamento de Fisica

    2015-04-15

    Neurological studies, for example, an investigation of hydrocephalus depends on the diagnostic tool used to determine the dimensions of the brain cavities. For this purpose, many studies have been used magnetic resonance imaging (MRI); however, this technique is expensive, which sometimes restricts research. Another way to investigate hydrocephalus is using conventional ultrasound that produces images based on the anatomical acoustic impedance difference, providing measurements of the neurological structures size. In addition, a technique that has gained relevance in biomedical scope is called photoacoustic imaging (PA), which consists in an anatomical image based on the optical contrast, allowing differentiate tissue by optical absorption and ultrasonic waves scattering. In order to continue the development of ultrasonic techniques, we present here a protocol using conventional ultrasound and PA imaging techniques focused to provide information for neurological research. We proposed a configuration for both, conventional and FA, which acquires data in RAW format. Then we use brains post-mortem of mice as a target. The collected data was processed into B-mode images and rendered in a 3D volume. This process permitted to measure the volume of intraventricular liquid. (author)

  20. Diffusion-weighted imaging as part of hybrid PET/MRI protocols for whole-body cancer staging: Does it benefit lesion detection?

    Energy Technology Data Exchange (ETDEWEB)

    Buchbender, Christian, E-mail: christian.buchbender@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Hartung-Knemeyer, Verena, E-mail: verena.hartung@uk-essen.de [Univ Duisburg-Essen, Medical Faculty, Department of Nuclear Medicine, Hufelandstr. 55, D-45147 Essen (Germany); Beiderwellen, Karsten, E-mail: karsten.beiderwellen@uk-essen.de [Univ Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Hufelandstr. 55, D-45147 Essen (Germany); Heusch, Philipp, E-mail: philipp.heusch@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Kühl, Hilmar, E-mail: hilmar.kuehl@uni-due.de [Univ Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Hufelandstr. 55, D-45147 Essen (Germany); Lauenstein, Thomas C., E-mail: thomas.lauenstein@uk-essen.de [Univ Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Hufelandstr. 55, D-45147 Essen (Germany); Forsting, Michael, E-mail: michael.forsting@uk-essen.de [Univ Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Hufelandstr. 55, D-45147 Essen (Germany); Antoch, Gerald, E-mail: antoch@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Heusner, Till A., E-mail: heusner@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany)

    2013-05-15

    Purpose: Positron emission tomography/magnetic resonance imaging (PET/MRI) requires efficient scan protocols for whole-body cancer staging. The aim of this study was to evaluate if the application of diffusion-weighted MR imaging (DWI) results in a diagnostic benefit for lesion detection in oncologic patients if added to a whole-body [18F]-fluorodesoxyglucose ([18F]-FDG) PET/MRI protocol. Methods: 25 consecutive oncologic patients (16 men, 9 women; age 57 ± 12 years) prospectively underwent whole-body [18F]-FDG-PET/MRI including DWI on a hybrid PET/MRI scanner. A team of two readers assessed [18F]-FDG PET/MRI without DWI for primary tumors and metastases. In a second session, now considering DWI, readers reassessed [18F]-FDG PET/MRI accordingly. Additionally, the lesion-to-background contrast on [18F]-FDG PET and DWI was rated qualitatively (0, invisible; 1, low; 2, intermediate; 3, high). Wilcoxon's signed-rank test was performed to test for differences in the lesion-to-background contrast. Results: 49 lesions were detected in 16 patients (5 primaries, 44 metastases). All 49 lesions were concordantly detected by [18F]-FDG PET/MRI alone and [18F]-FDG PET/MRI with DWI. The lesion-to-background contrast on DWI compared to [18F]-FDG PET was rated lower in 22 (44.9%) of 49 detected lesions resulting in a significantly higher lesion-to-background contrast on [18F]-FDG PET compared to DWI (P = 0.001). Conclusions: DWI as part of whole-body [18F]-FDG PET/MRI does not benefit lesion detection. Given the necessity to optimize imaging protocols with regard to patient comfort and efficacy, DWI has to be questioned as a standard tool for whole-body staging in oncologic PET/MRI.

  1. Q-ball imaging models: comparison between high and low angular resolution diffusion-weighted MRI protocols for investigation of brain white matter integrity

    Energy Technology Data Exchange (ETDEWEB)

    Caiazzo, Giuseppina; Trojsi, Francesca; Cirillo, Mario; Tedeschi, Gioacchino [MRI Research Center SUN-FISM-Neurological Institute for Diagnosis and Care ' ' Hermitage Capodimonte' ' , Naples (Italy); Second University of Naples, Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Naples (Italy); Esposito, Fabrizio [University of Salerno, Department of Medicine and Surgery, Baronissi (Salerno) (Italy); Maastricht University, Department of Cognitive Neuroscience, Maastricht (Netherlands)

    2016-02-15

    Q-ball imaging (QBI) is one of the typical data models for quantifying white matter (WM) anisotropy in diffusion-weighted MRI (DwMRI) studies. Brain and spinal investigation by high angular resolution DwMRI (high angular resolution imaging (HARDI)) protocols exhibits higher angular resolution in diffusion imaging compared to low angular resolution models, although with longer acquisition times. We aimed to assess the difference between QBI-derived anisotropy values from high and low angular resolution DwMRI protocols and their potential advantages or shortcomings in neuroradiology. Brain DwMRI data sets were acquired in seven healthy volunteers using both HARDI (b = 3000 s/mm{sup 2}, 54 gradient directions) and low angular resolution (b = 1000 s/mm{sup 2}, 32 gradient directions) acquisition schemes. For both sequences, tract of interest tractography and generalized fractional anisotropy (GFA) measures were extracted by using QBI model and were compared between the two data sets. QBI tractography and voxel-wise analyses showed that some WM tracts, such as corpus callosum, inferior longitudinal, and uncinate fasciculi, were reconstructed as one-dominant-direction fiber bundles with both acquisition schemes. In these WM tracts, mean percent different difference in GFA between the two data sets was less than 5 %. Contrariwise, multidirectional fiber bundles, such as corticospinal tract and superior longitudinal fasciculus, were more accurately depicted by HARDI acquisition scheme. Our results suggest that the design of optimal DwMRI acquisition protocols for clinical investigation of WM anisotropy by QBI models should consider the specific brain target regions to be explored, inducing researchers to a trade-off choice between angular resolution and acquisition time. (orig.)

  2. MR imaging of the ankle at 3 Tesla and 1.5 Tesla: protocol optimization and application to cartilage, ligament and tendon pathology in cadaver specimens

    International Nuclear Information System (INIS)

    Barr, Cameron; Malfair, David; Henning, Tobias D.; Steinbach, Lynne; Link, Thomas M.; Bauer, Jan S.; Ma, Benjamin

    2007-01-01

    The objective of this study was to optimize ankle joint MR imaging in volunteers at 1.5 Tesla (T) and 3.0 T, and to compare these optimized sequences concerning image quality and performance in assessing cartilage, ligament and tendon pathology in fresh human cadaver specimens. Initially our clinical ankle protocol consisting of T1-weighted (-w), fat-saturated (fs) T2-w, and short τ inversion-recovery fast spinecho (FSE) sequences was optimized at 1.5 T and 3.0 T by two radiologists. For dedicated cartilage imaging, fs-intermediate (IM)-w FSE, fs spoiled gradient echo, and balanced free-precession steady-state sequences were optimized. Using the optimized sequences, thirteen cadaver ankle joints were imaged. Four radiologists independently assessed these images concerning image quality and pathology. All radiologists consistently rated image quality higher at 3.0 T (all sequences p<0.05). For detecting cartilage pathology, diagnostic performance was significantly higher at 3.0 T (ROC-values up to 0.93 vs. 0.77; p<0.05); the fs-IM FSE sequence showed highest values among the different sequences. Average sensitivity for detecting tendon pathology was 63% at 3.0 T vs. 41% at 1.5 T and was significantly higher at 3.0 T for 2 out of 4 radiologists (p<0.05). Compared to 1.5 T, imaging of the ankle joint at 3.0 T significantly improved image quality and diagnostic performance in assessing cartilage pathology. (orig.)

  3. Cardiac magnetic resonance and the need for routine cardiac catheterization in single ventricle patients prior to Fontan: a comparison of 3 groups: pre-Fontan CMR versus cath evaluation.

    Science.gov (United States)

    Fogel, Mark A; Pawlowski, Thomas W; Whitehead, Kevin K; Harris, Matthew A; Keller, Marc S; Glatz, Andrew C; Zhu, Winnie; Shore, David; Diaz, Laura K; Rome, Jonathan J

    2012-09-18

    This study investigated whether cardiac magnetic resonance (CMR) and echocardiography (echo) can replace catheterization (cath) for routine evaluation prior to Fontan and under what circumstances CMR and cath are used together. Routine cath prior to Fontan has been utilized for years; noninvasive methods, however, may be sufficient. This study reviews clinical data in 119 consecutive patients investigating 3 groups: those who underwent CMR alone (MR; n = 41), cath alone (C; n = 41), or both cath and CMR (C+M; n = 37) prior to Fontan. No clinically significant differences were noted in patient characteristics, hemodynamics, or clinical status prior to or after surgery between the C and MR groups. CMR added information in 82%. There were no discrepant findings between CMR and cath data in the C+M group. Diagnostic success was ≥95% in all groups. Of those undergoing Fontan completion, the C+M group had similar outcomes to C and MR; C and CMR were utilized in combination to assess aortopulmonary collaterals or the need for an intervention or evaluate its success. Echo could not delineate pulmonary arterial anatomy in 46% to 53% of patients. The C+M and C groups were exposed to 6.8 ± 4.1 mSv of radiation. Single ventricle patients not requiring an intervention can undergo successful Fontan completion with CMR and echo alone with similar short-term outcomes to C, which was used as a control, preventing an invasive test and exposure to radiation. CMR can add information in a significant number of patients. Cath and CMR are utilized together for interventions and assessment of aortopulmonary collaterals. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  4. Nuclear myocardial perfusion imaging using thallium-201 with a novel multifocal collimator SPECT/CT: IQ-SPECT versus conventional protocols in normal subjects.

    Science.gov (United States)

    Matsuo, Shinro; Nakajima, Kenichi; Onoguchi, Masahisa; Wakabayash, Hiroshi; Okuda, Koichi; Kinuya, Seigo

    2015-06-01

    A novel multifocal collimator, IQ-SPECT (Siemens) consists of SMARTZOOM, cardio-centric and 3D iterative SPECT reconstruction and makes it possible to perform MPI scans in a short time. The aims are to delineate the normal uptake in thallium-201 ((201)Tl) SPECT in each acquisition method and to compare the distribution between new and conventional protocol, especially in patients with normal imaging. Forty patients (eight women, mean age of 75 years) who underwent myocardial perfusion imaging were included in the study. All patients underwent one-day protocol perfusion scan after an adenosine-stress test and at rest after administering (201)Tl and showed normal results. Acquisition was performed on a Symbia T6 equipped with a conventional dual-headed gamma camera system (Siemens ECAM) and with a multifocal SMARTZOOM collimator. Imaging was performed with a conventional system followed by IQ-SPECT/computed tomography (CT). Reconstruction was performed with or without X-ray CT-derived attenuation correction (AC). Two nuclear physicians blinded to clinical information interpreted all myocardial perfusion images. A semi-quantitative myocardial perfusion was analyzed by a 17-segment model with a 5-point visual scoring. The uptake of each segment was measured and left ventricular functions were analyzed by QPS software. IQ-SPECT provided good or excellent image quality. The quality of IQ-SPECT images without AC was similar to those of conventional LEHR study. Mid-inferior defect score (0.3 ± 0.5) in the conventional LEHR study was increased significantly in IQ-SPECT with AC (0 ± 0). IQ-SPECT with AC improved the mid-inferior decreased perfusion shown in conventional images. The apical tracer count in IQ-SPECT with AC was decreased compared to that in LEHR (0.1 ± 0.3 vs. 0.5 ± 0.7, p IQ-SPECT was significantly higher than that from the LEHR collimator (p = 0.0009). The images of IQ-SPECT acquired in a short time are equivalent to that of conventional LEHR

  5. Fusion of CT coronary angiography and whole-heart dynamic 3D cardiac MR perfusion: building a framework for comprehensive cardiac imaging.

    Science.gov (United States)

    von Spiczak, Jochen; Manka, Robert; Gotschy, Alexander; Oebel, Sabrina; Kozerke, Sebastian; Hamada, Sandra; Alkadhi, Hatem

    2018-04-01

    The purpose of this work was to develop a framework for 3D fusion of CT coronary angiography (CTCA) and whole-heart dynamic 3D cardiac magnetic resonance perfusion (3D-CMR-Perf) image data-correlating coronary artery stenoses to stress-induced myocardial perfusion deficits for the assessment of coronary artery disease (CAD). Twenty-three patients who underwent CTCA and 3D-CMR-Perf for various indications were included retrospectively. For CTCA, image quality and coronary diameter stenoses > 50% were documented. For 3D-CMR-Perf, image quality and stress-induced perfusion deficits were noted. A software framework was developed to allow for 3D image fusion of both datasets. Computation steps included: (1) fully automated segmentation of coronary arteries and heart contours from CT; (2) manual segmentation of the left ventricle in 3D-CMR-Perf images; (3) semi-automatic co-registration of CT/CMR datasets; (4) projection of the 3D-CMR-Perf values on the CT left ventricle. 3D fusion analysis was compared to separate inspection of CTCA and 3D-CMR-Perf data. CT and CMR scans resulted in an image quality being rated as good to excellent (mean scores 3.5 ± 0.5 and 3.7 ± 0.4, respectively, scale 1-4). 3D-fusion was feasible in all 23 patients, and perfusion deficits could be correlated to culprit coronary lesions in all but one case (22/23 = 96%). Compared to separate analysis of CT and CMR data, coronary supply territories of 3D-CMR-Perf perfusion deficits were refined in two cases (2/23 = 9%), and the relevance of stenoses in CTCA was re-judged in four cases (4/23 = 17%). In conclusion, 3D fusion of CTCA/3D-CMR-Perf facilitates anatomic correlation of coronary lesions and stress-induced myocardial perfusion deficits thereby helping to refine diagnostic assessment of CAD.

  6. Two-View Gravity Stress Imaging Protocol for Nondisplaced Type II Supination External Rotation Ankle Fractures: Introducing the Gravity Stress Cross-Table Lateral View.

    Science.gov (United States)

    Boffeli, Troy J; Collier, Rachel C; Gervais, Samuel J

    Assessing ankle stability in nondisplaced Lauge-Hansen supination external rotation type II injuries requires stress imaging. Gravity stress mortise imaging is routinely used as an alternative to manual stress imaging to assess deltoid integrity with the goal of differentiating type II from type IV injuries in cases without a posterior or medial fracture. A type II injury with a nondisplaced fibula fracture is typically treated with cast immobilization, and a type IV injury is considered unstable and often requires operative repair. The present case series (two patients) highlights a standardized 2-view gravity stress imaging protocol and introduces the gravity stress cross-table lateral view. The gravity stress cross-table lateral view provides a more thorough evaluation of the posterior malleolus owing to the slight external rotation and posteriorly directed stress. External rotation also creates less bony overlap between the tibia and fibula, allowing for better visualization of the fibula fracture. Gravity stress imaging confirmed medial-sided injury in both cases, confirming the presence of supination external rotation type IV or bimalleolar equivalent fractures. Open reduction and internal fixation was performed, and both patients achieved radiographic union. No further treatment was required at 21 and 33 months postoperatively. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  7. Optimization of the dose versus noise in the image on protocols for computed tomography of pediatric head;Otimizacao da relacao dose versus ruido na imagem em protocolos de tomografia computadorizada de cranio pediatrico

    Energy Technology Data Exchange (ETDEWEB)

    Saint' Yves, T.L.A.; Travassos, P.C.; Goncalves, E.A.S.; Mecca, F.A.; Silveira, T.B. [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    This article aims to establish protocols optimized for computed tomography of pediatric skull, to the Picker Q 2000 tomography of the Instituto Nacional de Cancer, through the analysis of dose x noise on the image with the variation of values of m As and k Vp. We used a water phantom to measure the noise, a pencil type ionization chamber to measure the dose in the air and the Alderson Randon phantom for check the quality of the image. We found values of m As and k Vp that reduce the skin dose of the original protocol used in 35.9%, maintaining the same image quality at a safe diagnosis. (author)

  8. Quality assurance in MRI breast screening: comparing signal-to-noise ratio in dynamic contrast-enhanced imaging protocols

    Science.gov (United States)

    Kousi, Evanthia; Borri, Marco; Dean, Jamie; Panek, Rafal; Scurr, Erica; Leach, Martin O.; Schmidt, Maria A.

    2016-01-01

    MRI has been extensively used in breast cancer staging, management and high risk screening. Detection sensitivity is paramount in breast screening, but variations of signal-to-noise ratio (SNR) as a function of position are often overlooked. We propose and demonstrate practical methods to assess spatial SNR variations in dynamic contrast-enhanced (DCE) breast examinations and apply those methods to different protocols and systems. Four different protocols in three different MRI systems (1.5 and 3.0 T) with receiver coils of different design were employed on oil-filled test objects with and without uniformity filters. Twenty 3D datasets were acquired with each protocol; each dataset was acquired in under 60 s, thus complying with current breast DCE guidelines. In addition to the standard SNR calculated on a pixel-by-pixel basis, we propose other regional indices considering the mean and standard deviation of the signal over a small sub-region centred on each pixel. These regional indices include effects of the spatial variation of coil sensitivity and other structured artefacts. The proposed regional SNR indices demonstrate spatial variations in SNR as well as the presence of artefacts and sensitivity variations, which are otherwise difficult to quantify and might be overlooked in a clinical setting. Spatial variations in SNR depend on protocol choice and hardware characteristics. The use of uniformity filters was shown to lead to a rise of SNR values, altering the noise distribution. Correlation between noise in adjacent pixels was associated with data truncation along the phase encoding direction. Methods to characterise spatial SNR variations using regional information were demonstrated, with implications for quality assurance in breast screening and multi-centre trials.

  9. Imaging children suffering from lymphoma: an evaluation of different 18F-FDG PET/MRI protocols compared to whole-body DW-MRI.

    Science.gov (United States)

    Kirchner, Julian; Deuschl, Cornelius; Schweiger, Bernd; Herrmann, Ken; Forsting, Michael; Buchbender, Christian; Antoch, Gerald; Umutlu, Lale

    2017-09-01

    The objectives of this study were to evaluate and compare the diagnostic potential of different PET/MRI reading protocols, entailing non-enhanced / contrast-enhanced and diffusion-weighted 18 F-FDG PET/MR imaging and whole-body diffusion-weighted MRI for lesion detection and determination of the tumor stage in pediatric lymphoma patients. A total of 28 18 F-FDG PET/MRI datasets were included for analysis of four different reading protocols: (1) PET/MRI utilizing sole unenhanced T2w and T1w imaging, (2) PET/MRI utilizing additional contrast enhanced sequences, (3) PET/MR imaging utilizing unenhanced, contrast enhanced and DW imaging or (4) WB-DW-MRI. Statistical analyses were performed on a per-patient and a per-lesion basis. Follow-up and prior examinations as well as histopathology served as reference standards. PET/MRI correctly identified all 17 examinations with active lymphoma disease, while WB-DW-MRI correctly identified 15/17 examinations. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 96%, 96.5%, 97%, 95%, and 96% for PET/MRI 1 ; 97%, 96.5%, 97%, 96.5%, and 97% for PET/MRI 2 ; 97%, 96.5%, 97%, 96.5%, and 97% for PET/MRI 3 and 77%, 96%, 96%, 78.5% and 86% for MRI-DWI. 18 F-FDG PET/MRI is superior to WB-DW-MRI in staging pediatric lymphoma patients. Neither application of contrast media nor DWI leads to a noticeable improvement of the diagnostic accuracy of PET/MRI. Thus, unenhanced PET/MRI may play a crucial role for the diagnostic work-up of pediatric lymphoma patients in the future.

  10. Comprehensive small animal imaging strategies on a clinical 3 T dedicated head MR-scanner; adapted methods and sequence protocols in CNS pathologies.

    Directory of Open Access Journals (Sweden)

    Deepu R Pillai

    Full Text Available BACKGROUND: Small animal models of human diseases are an indispensable aspect of pre-clinical research. Being dynamic, most pathologies demand extensive longitudinal monitoring to understand disease mechanisms, drug efficacy and side effects. These considerations often demand the concomitant development of monitoring systems with sufficient temporal and spatial resolution. METHODOLOGY AND RESULTS: This study attempts to configure and optimize a clinical 3 Tesla magnetic resonance scanner to facilitate imaging of small animal central nervous system pathologies. The hardware of the scanner was complemented by a custom-built, 4-channel phased array coil system. Extensive modification of standard sequence protocols was carried out based on tissue relaxometric calculations. Proton density differences between the gray and white matter of the rodent spinal cord along with transverse relaxation due to magnetic susceptibility differences at the cortex and striatum of both rats and mice demonstrated statistically significant differences. The employed parallel imaging reconstruction algorithms had distinct properties dependent on the sequence type and in the presence of the contrast agent. The attempt to morphologically phenotype a normal healthy rat brain in multiple planes delineated a number of anatomical regions, and all the clinically relevant sequels following acute cerebral ischemia could be adequately characterized. Changes in blood-brain-barrier permeability following ischemia-reperfusion were also apparent at a later time. Typical characteristics of intra-cerebral haemorrhage at acute and chronic stages were also visualized up to one month. Two models of rodent spinal cord injury were adequately characterized and closely mimicked the results of histological studies. In the employed rodent animal handling system a mouse model of glioblastoma was also studied with unequivocal results. CONCLUSIONS: The implemented customizations including extensive

  11. Comprehensive Small Animal Imaging Strategies on a Clinical 3 T Dedicated Head MR-Scanner; Adapted Methods and Sequence Protocols in CNS Pathologies

    Science.gov (United States)

    Pillai, Deepu R.; Heidemann, Robin M.; Lanz, Titus; Dittmar, Michael S.; Sandner, Beatrice; Beier, Christoph P.; Weidner, Norbert; Greenlee, Mark W.; Schuierer, Gerhard; Bogdahn, Ulrich; Schlachetzki, Felix

    2011-01-01

    Background Small animal models of human diseases are an indispensable aspect of pre-clinical research. Being dynamic, most pathologies demand extensive longitudinal monitoring to understand disease mechanisms, drug efficacy and side effects. These considerations often demand the concomitant development of monitoring systems with sufficient temporal and spatial resolution. Methodology and Results This study attempts to configure and optimize a clinical 3 Tesla magnetic resonance scanner to facilitate imaging of small animal central nervous system pathologies. The hardware of the scanner was complemented by a custom-built, 4-channel phased array coil system. Extensive modification of standard sequence protocols was carried out based on tissue relaxometric calculations. Proton density differences between the gray and white matter of the rodent spinal cord along with transverse relaxation due to magnetic susceptibility differences at the cortex and striatum of both rats and mice demonstrated statistically significant differences. The employed parallel imaging reconstruction algorithms had distinct properties dependent on the sequence type and in the presence of the contrast agent. The attempt to morphologically phenotype a normal healthy rat brain in multiple planes delineated a number of anatomical regions, and all the clinically relevant sequels following acute cerebral ischemia could be adequately characterized. Changes in blood-brain-barrier permeability following ischemia-reperfusion were also apparent at a later time. Typical characteristics of intra-cerebral haemorrhage at acute and chronic stages were also visualized up to one month. Two models of rodent spinal cord injury were adequately characterized and closely mimicked the results of histological studies. In the employed rodent animal handling system a mouse model of glioblastoma was also studied with unequivocal results. Conclusions The implemented customizations including extensive sequence protocol

  12. Imaging children suffering from lymphoma: an evaluation of different {sup 18}F-FDG PET/MRI protocols compared to whole-body DW-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kirchner, Julian; Buchbender, Christian; Antoch, Gerald [University Dusseldorf, Department of Diagnostic and Interventional Radiology, Medical Faculty, Dusseldorf (Germany); Deuschl, Cornelius; Schweiger, Bernd; Forsting, Michael; Umutlu, Lale [University Hospital Essen, University of Duisburg-Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Herrmann, Ken [University Hospital Essen, University of Duisburg-Essen, Department of Nuclear Medicine, Essen (Germany)

    2017-09-15

    The objectives of this study were to evaluate and compare the diagnostic potential of different PET/MRI reading protocols, entailing non-enhanced / contrast-enhanced and diffusion-weighted {sup 18}F-FDG PET/MR imaging and whole-body diffusion-weighted MRI for lesion detection and determination of the tumor stage in pediatric lymphoma patients. A total of 28 {sup 18}F-FDG PET/MRI datasets were included for analysis of four different reading protocols: (1) PET/MRI utilizing sole unenhanced T2w and T1w imaging, (2) PET/MRI utilizing additional contrast enhanced sequences, (3) PET/MR imaging utilizing unenhanced, contrast enhanced and DW imaging or (4) WB-DW-MRI. Statistical analyses were performed on a per-patient and a per-lesion basis. Follow-up and prior examinations as well as histopathology served as reference standards. PET/MRI correctly identified all 17 examinations with active lymphoma disease, while WB-DW-MRI correctly identified 15/17 examinations. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 96%, 96.5%, 97%, 95%, and 96% for PET/MRI{sub 1}; 97%, 96.5%, 97%, 96.5%, and 97% for PET/MRI{sub 2}; 97%, 96.5%, 97%, 96.5%, and 97% for PET/MRI{sub 3} and 77%, 96%, 96%, 78.5% and 86% for MRI-DWI. {sup 18}F-FDG PET/MRI is superior to WB-DW-MRI in staging pediatric lymphoma patients. Neither application of contrast media nor DWI leads to a noticeable improvement of the diagnostic accuracy of PET/MRI. Thus, unenhanced PET/MRI may play a crucial role for the diagnostic work-up of pediatric lymphoma patients in the future. (orig.)

  13. Left ventricular thrombus formation after acute myocardial infarction as assessed by cardiovascular magnetic resonance imaging

    International Nuclear Information System (INIS)

    Delewi, Ronak; Nijveldt, Robin; Hirsch, Alexander; Marcu, Constantin B.; Robbers, Lourens; Hassell, Marriela E.C.J.; Bruin, Rianne H.A. de; Vleugels, Jim; Laan, Anja M. van der; Bouma, Berto J.; Tio, René A.; Tijssen, Jan G.P.; Rossum, Albert C. van; Zijlstra, Felix; Piek, Jan J.

    2012-01-01

    Introduction: Left ventricular (LV) thrombus formation is a feared complication of myocardial infarction (MI). We assessed the prevalence of LV thrombus in ST-segment elevated MI patients treated with percutaneous coronary intervention (PCI) and compared the diagnostic accuracy of transthoracic echocardiography (TTE) to cardiovascular magnetic resonance imaging (CMR). Also, we evaluated the course of LV thrombi in the modern era of primary PCI. Methods: 200 patients with primary PCI underwent TTE and CMR, at baseline and at 4 months follow-up. Studies were analyzed by two blinded examiners. Patients were seen at 1, 4, 12, and 24 months for assessment of clinical status and adverse events. Results: On CMR at baseline, a thrombus was found in 17 of 194 (8.8%) patients. LV thrombus resolution occurred in 15 patients. Two patients had persistence of LV thrombus on follow-up CMR. On CMR at four months, a thrombus was found in an additional 12 patients. In multivariate analysis, thrombus formation on baseline CMR was independently associated with, baseline infarct size (g) (B = 0.02, SE = 0.02, p < 0.001). Routine TTE had a sensitivity of 21–24% and a specificity of 95–98% compared to CMR for the detection of LV thrombi. Intra- and interobserver variation for detection of LV thrombus were lower for CMR (κ = 0.91 and κ = 0.96) compared to TTE (κ = 0.74 and κ = 0.53). Conclusion: LV thrombus still occurs in a substantial amount of patients after PCI-treated MI, especially in larger infarct sizes. Routine TTE had a low sensitivity for the detection of LV thrombi and the interobserver variation of TTE was large.

  14. Left ventricular thrombus formation after acute myocardial infarction as assessed by cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Delewi, Ronak [Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Interuniversity Cardiology Institute of the Netherlands (Netherlands); Nijveldt, Robin [Department of Cardiology, VU University Medical Center, Amsterdam (Netherlands); Hirsch, Alexander [Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Marcu, Constantin B.; Robbers, Lourens [Department of Cardiology, VU University Medical Center, Amsterdam (Netherlands); Hassell, Marriela E.C.J.; Bruin, Rianne H.A. de; Vleugels, Jim; Laan, Anja M. van der; Bouma, Berto J. [Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Tio, René A. [Thorax Center, University Medical Center Groningen, Groningen (Netherlands); Tijssen, Jan G.P. [Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Rossum, Albert C. van [Department of Cardiology, VU University Medical Center, Amsterdam (Netherlands); Zijlstra, Felix [Thorax Center, Department of Cardiology, Erasmus University Medical Center, Rotterdam (Netherlands); Piek, Jan J., E-mail: j.j.piek@amc.uva.nl [Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands)

    2012-12-15

    Introduction: Left ventricular (LV) thrombus formation is a feared complication of myocardial infarction (MI). We assessed the prevalence of LV thrombus in ST-segment elevated MI patients treated with percutaneous coronary intervention (PCI) and compared the diagnostic accuracy of transthoracic echocardiography (TTE) to cardiovascular magnetic resonance imaging (CMR). Also, we evaluated the course of LV thrombi in the modern era of primary PCI. Methods: 200 patients with primary PCI underwent TTE and CMR, at baseline and at 4 months follow-up. Studies were analyzed by two blinded examiners. Patients were seen at 1, 4, 12, and 24 months for assessment of clinical status and adverse events. Results: On CMR at baseline, a thrombus was found in 17 of 194 (8.8%) patients. LV thrombus resolution occurred in 15 patients. Two patients had persistence of LV thrombus on follow-up CMR. On CMR at four months, a thrombus was found in an additional 12 patients. In multivariate analysis, thrombus formation on baseline CMR was independently associated with, baseline infarct size (g) (B = 0.02, SE = 0.02, p < 0.001). Routine TTE had a sensitivity of 21–24% and a specificity of 95–98% compared to CMR for the detection of LV thrombi. Intra- and interobserver variation for detection of LV thrombus were lower for CMR (κ = 0.91 and κ = 0.96) compared to TTE (κ = 0.74 and κ = 0.53). Conclusion: LV thrombus still occurs in a substantial amount of patients after PCI-treated MI, especially in larger infarct sizes. Routine TTE had a low sensitivity for the detection of LV thrombi and the interobserver variation of TTE was large.

  15. Cardiovascular magnetic resonance imaging in hypertrophic cardiomyopathy: Current state of the art.

    Science.gov (United States)

    Kamal, Muhammad Umar; Riaz, Irbaz Bin; Janardhanan, Rajesh

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy with a prevalence of 1:500 (0.2%) in the general population. Sudden cardiac death (SCD) is the most feared presentation of HCM. Therefore, it is essential to identify individuals at high risk in order to prevent SCD. The absence of conventional risk factors does not nullify the risk of HCM related SCD. Although echocardiography is currently the most widely used imaging modality, cardiac magnetic resonance (CMR) allows detailed characterization of the HCM phenotype, which makes it possible to differentiate HCM from other causes of left ventricular hypertrophy. CMR has the potential to further refine risk stratification. Late gadolinium enhancement (LGE) on CMR is a high-risk feature and there is emerging data to suggest that the presence of LGE should be employed as a marker for major adverse outcomes such as SCD, arrhythmias, systolic and diastolic heart failure. Hence, LGE on CMR may be considered an additional risk factor for SCD in HCM patients and should be incorporated in decision-making for implant-able cardioverter defibrillator implantation to aid primary prevention. Novel markers such as the extent of myocardial fibrosis on CMR must be accounted for comprehensive risk stratifica-tion of HCM patients. The purpose of this review is to discuss the current status and emerging role of CMR in HCM.

  16. A New Colorimetrically-Calibrated Automated Video-Imaging Protocol for Day-Night Fish Counting at the OBSEA Coastal Cabled Observatory

    Directory of Open Access Journals (Sweden)

    Joaquín del Río

    2013-10-01

    Full Text Available Field measurements of the swimming activity rhythms of fishes are scant due to the difficulty of counting individuals at a high frequency over a long period of time. Cabled observatory video monitoring allows such a sampling at a high frequency over unlimited periods of time. Unfortunately, automation for the extraction of biological information (i.e., animals’ visual counts per unit of time is still a major bottleneck. In this study, we describe a new automated video-imaging protocol for the 24-h continuous counting of fishes in colorimetrically calibrated time-lapse photographic outputs, taken by a shallow water (20 m depth cabled video-platform, the OBSEA. The spectral reflectance value for each patch was measured between 400 to 700 nm and then converted into standard RGB, used as a reference for all subsequent calibrations. All the images were acquired within a standardized Region Of Interest (ROI, represented by a 2 × 2 m methacrylate panel, endowed with a 9-colour calibration chart, and calibrated using the recently implemented “3D Thin-Plate Spline” warping approach in order to numerically define color by its coordinates in n-dimensional space. That operation was repeated on a subset of images, 500 images as a training set, manually selected since acquired under optimum visibility conditions. All images plus those for the training set were ordered together through Principal Component Analysis allowing the selection of 614 images (67.6% out of 908 as a total corresponding to 18 days (at 30 min frequency. The Roberts operator (used in image processing and computer vision for edge detection was used to highlights regions of high spatial colour gradient corresponding to fishes’ bodies. Time series in manual and visual counts were compared together for efficiency evaluation. Periodogram and waveform analysis outputs provided very similar results, although quantified parameters in relation to the strength of respective rhythms were

  17. A new colorimetrically-calibrated automated video-imaging protocol for day-night fish counting at the OBSEA coastal cabled observatory.

    Science.gov (United States)

    del Río, Joaquín; Aguzzi, Jacopo; Costa, Corrado; Menesatti, Paolo; Sbragaglia, Valerio; Nogueras, Marc; Sarda, Francesc; Manuèl, Antoni

    2013-10-30

    Field measurements of the swimming activity rhythms of fishes are scant due to the difficulty of counting individuals at a high frequency over a long period of time. Cabled observatory video monitoring allows such a sampling at a high frequency over unlimited periods of time. Unfortunately, automation for the extraction of biological information (i.e., animals' visual counts per unit of time) is still a major bottleneck. In this study, we describe a new automated video-imaging protocol for the 24-h continuous counting of fishes in colorimetrically calibrated time-lapse photographic outputs, taken by a shallow water (20 m depth) cabled video-platform, the OBSEA. The spectral reflectance value for each patch was measured between 400 to 700 nm and then converted into standard RGB, used as a reference for all subsequent calibrations. All the images were acquired within a standardized Region Of Interest (ROI), represented by a 2 × 2 m methacrylate panel, endowed with a 9-colour calibration chart, and calibrated using the recently implemented "3D Thin-Plate Spline" warping approach in order to numerically define color by its coordinates in n-dimensional space. That operation was repeated on a subset of images, 500 images as a training set, manually selected since acquired under optimum visibility conditions. All images plus those for the training set were ordered together through Principal Component Analysis allowing the selection of 614 images (67.6%) out of 908 as a total corresponding to 18 days (at 30 min frequency). The Roberts operator (used in image processing and computer vision for edge detection) was used to highlights regions of high spatial colour gradient corresponding to fishes' bodies. Time series in manual and visual counts were compared together for efficiency evaluation. Periodogram and waveform analysis outputs provided very similar results, although quantified parameters in relation to the strength of respective rhythms were different. Results

  18. Usefulness of 3-Tesla cardiac magnetic resonance imaging in the assessment of aortic stenosis severity in routine clinical practice.

    Science.gov (United States)

    Levy, Franck; Iacuzio, Laura; Civaia, Filippo; Rusek, Stephane; Dommerc, Carine; Hugues, Nicolas; Alexandrescu, Clara; Dor, Vincent; Tribouilloy, Christophe; Dreyfus, Gilles

    2016-11-01

    Recently, 1.5-Tesla cardiac magnetic resonance imaging (CMR) was reported to provide a reliable alternative to transthoracic echocardiography (TTE) for the quantification of aortic stenosis (AS) severity. Few data are available using higher magnetic field strength MRI systems in this context. To evaluate the feasibility and reproducibility of the assessment of aortic valve area (AVA) using 3-Tesla CMR in routine clinical practice, and to assess concordance between TTE and CMR for the estimation of AS severity. Ninety-one consecutive patients (60 men; mean age 74±10years) with known AS documented by TTE were included prospectively in the study. All patients underwent comprehensive TTE and CMR examination, including AVA estimation using the TTE continuity equation (0.81±0.18cm 2 ), direct CMR planimetry (CMRp) (0.90±0.22cm 2 ) and CMR using Hakki's formula (CMRhk), a simplified Gorlin formula (0.70±0.19cm 2 ). Although significant agreement with TTE was found for CMRp (r=0.72) and CMRhk (r=0.66), CMRp slightly overestimated (bias=0.11±0.18cm 2 ) and CMRhk slightly underestimated (bias=-0.11±0.17cm 2 ) AVA compared with TTE. Inter- and intraobserver reproducibilities of CMR measurements were excellent (r=0.72 and r=0.74 for CMRp and r=0.88 and r=0.92 for peak aortic velocity, respectively). 3-Tesla CMR is a feasible, radiation-free, reproducible imaging modality for the estimation of severity of AS in routine practice, knowing that CMRp tends to overestimate AVA and CMRhk to underestimate AVA compared with TTE. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  19. Imaging the Spatial Distribution of Transport Currents and the Phenomenon of Nanoscale Phase Separation Phenomenon in CMR Materials

    National Research Council Canada - National Science Library

    Banerjee, Satyajit

    2007-01-01

    ... by transport currents sent through materials. Based on the above objective it was planned to apply this technique to investigate fundamental issues like magnetic phase separation in colossal magneto resistive materials as well as to investigate...

  20. Utility of CT after sonography for suspected appendicitis in children: integration of a clinical scoring system with a staged imaging protocol.

    Science.gov (United States)

    Srinivasan, Abhay; Servaes, Sabah; Peña, Andrès; Darge, Kassa

    2015-02-01

    To improve diagnosis of pediatric appendicitis, many institutions have implemented a staged imaging protocol utilizing ultrasonography (US) first and then computed tomography (CT). A substantial number of children with suspected appendicitis undergo CT after US, and the efficient and accurate diagnosis of pediatric appendicitis continues to be challenging. The objective of the study is to characterize the utility of CT following US for diagnosis of pediatric appendicitis, in conjunction with a clinical appendicitis score (AS). Imaging studies of children with suspected appendicitis who underwent CT after US in an imaging protocol were retrospectively reviewed by three radiologists in consensus. Chart review derived the AS (range 0-10) and obtained the patient diagnosis and disposition, and an AS was applied to each patient. Clinical and radiologic data were analyzed to assess the yield of CT after US. Studies of 211 children (mean age 11.3 years) were included. The positive threshold for AS was determined to be 6 out of 10. When AS and US were concordant (N = 140), the sensitivity and specificity of US were similar to CT. When AS and US were discordant (N = 71) and also when AS ≥ 6 (N = 84), subsequent CT showed superior sensitivity and specificity to US alone. In the subset where US showed neither the appendix nor inflammatory change in the right lower quadrant (126/211, 60 % of scans), when AS 6 (kg/year, P < 0.001) and after-hours (1700 -0730 hours) performance of US (P < 0.001). Results suggest that the appendicitis score has utility in guiding an imaging protocol and support the contention that non-visualization of the appendix on US is not intrinsically non-diagnostic. There was little benefit to additional CT when AS < 6 and US did not show the appendix or evidence of inflammation; this would have avoided CT in 140/211 (66 %) patients. CT demonstrated benefit when AS ≥ 6, suggesting that cases with AS ≥ 6 and

  1. Comprehensive low-dose imaging of carotid and coronary arteries with a single-injection dual-source CT angiography protocol

    International Nuclear Information System (INIS)

    Tognolini, A.; Arellano, C.S.; Marfori, W.; Heidari, G.; Sayre, J.W.; Krishnam, M.S.; Ruehm, S.G.

    2014-01-01

    Aim: To assess the feasibility of a fast single-bolus combined carotid and coronary computed tomography angiography (CTA) protocol in asymptomatic patients. Materials and methods: Thirty-three consecutive patients (18 women and 15 men) with a median age of 61 ± 14 years old (range 37–87 years) with known or suspected atherosclerotic disease were enrolled in this prospective study. A single breath-hold, single biphasic injection protocol (50 ml at 3 ml/s, 50 ml at 5 ml/s, 50 ml saline flush at 5 ml/s) was used for combined CTA imaging of the supra-aortic (SAA) and coronary arteries (CA) on a 64-slice dual-source CT (DSCT) machine. Helical CTA acquisition of the SAA was followed by prospective electrocardiography (ECG)-triggered coronary CTA. Subjective (four-point scale) image quality and objective signal-to-noise (SNR) and contrast-to-noise (CNR) measurements were performed. Vascular disease was graded on a four-point scale (grade 1: absent; grade 2: mild, grade 3: moderate; grade 4: severe). The radiation dose was recorded for each patient. Results: The average enhancement and subjective quality score of SAA and CA segments were 396 HU/358 HU and 1.2 ± 0.3/1.72 ± 0.4, respectively. The SNR was 27.1 ± 1.7 in the SAA and 21.6 ± 1.6 in the CA (p < 0.0001). The CNR was 18.1 ± 1.2 and 15.9 ± 1.8, respectively (p = 0.4). Four percent of SAA and 14% of CA segments (mostly due to peri-venous streak artefacts and small calibre, respectively) produced non-diagnostic images. SAA findings were as follows: 26/33 (79%) patients showed no disease and 6/33 (18%) had grade 2 and 1/33 (3%) had grade 3 disease. CA findings were as follows: 25/33 (76%) showed no disease and 6/33 (18%) patients had grade 2 and 2/33 (6%) had grade 3 disease. Five patients had disease in both districts. The average radiation dose for the combined CTA angiogram was 4.3 ± 0.6 mSv. Conclusion: A fast, low-dose combined DSCT angiography protocol appears technically feasible for imaging carotid and

  2. Bioremediation protocols

    National Research Council Canada - National Science Library

    Sheehan, David

    1997-01-01

    ..., .. . . . . .. ,. . . .. . . . . . . . .. . . . . .. . . .. . .. 3 2 Granular Nina Sludge Christiansen, Consortia lndra for Bioremediation, M. Mathrani, and Birgitte K. Ahring . 23 PART II PROTOCOLS...

  3. Low-dose X-ray computed tomography image reconstruction with a combined low-mAs and sparse-view protocol.

    Science.gov (United States)

    Gao, Yang; Bian, Zhaoying; Huang, Jing; Zhang, Yunwan; Niu, Shanzhou; Feng, Qianjin; Chen, Wufan; Liang, Zhengrong; Ma, Jianhua

    2014-06-16

    To realize low-dose imaging in X-ray computed tomography (CT) examination, lowering milliampere-seconds (low-mAs) or reducing the required number of projection views (sparse-view) per rotation around the body has been widely studied as an easy and effective approach. In this study, we are focusing on low-dose CT image reconstruction from the sinograms acquired with a combined low-mAs and sparse-view protocol and propose a two-step image reconstruction strategy. Specifically, to suppress significant statistical noise in the noisy and insufficient sinograms, an adaptive sinogram restoration (ASR) method is first proposed with consideration of the statistical property of sinogram data, and then to further acquire a high-quality image, a total variation based projection onto convex sets (TV-POCS) method is adopted with a slight modification. For simplicity, the present reconstruction strategy was termed as "ASR-TV-POCS." To evaluate the present ASR-TV-POCS method, both qualitative and quantitative studies were performed on a physical phantom. Experimental results have demonstrated that the present ASR-TV-POCS method can achieve promising gains over other existing methods in terms of the noise reduction, contrast-to-noise ratio, and edge detail preservation.

  4. Diagnostic value of a new myocardial perfusion agent, teboroxime (SO 30,217), utilizing a rapid planar imaging protocol: Preliminary results

    International Nuclear Information System (INIS)

    Hendel, R.C.; McSherry, B.; Karimeddini, M.; Leppo, J.A.

    1990-01-01

    Technetium-99m-labeled agents have advantages over thallium-201 in terms of photon statistics, cost and clinical availability. They have been suggested as an alternative to thallium for myocardial perfusion imaging. Teboroxime is a new boronic acid adduct of technetium dioxime (BATO) compound that demonstrates favorable characteristics in preliminary studies. With use of a novel (seated) patient positioning technique and a rapid dynamic acquisition protocol, 30 patients underwent planar imaging with teboroxoime while at rest and after maximal treadmill exercise. Postexercise scans were completed in an average time (mean +/- SD) of 4.4 +/- 1.6 min, with 4.8 +/- 1.5 min for the views at rest. These results were compared with coronary arteriography or thallium scintigraphy after treadmill exercise, or both. Diagnostic agreement (abnormal versus normal) was present in 28 of the 30 patients (p less than 0.001). Regarding physiologic assessment as compared with thallium scintigraphy, the finding of infarction and ischemia was concordant in 89% and 86% of patients, respectively. This report describes the initial use of teboroxime with a rapid dynamic planar imaging technique, resulting in a high correlation with exercise thallium scintigraphy. Delayed postexercise images obtained 5 to 10 min after exercise demonstrated rapid disappearance of exercise-induced defects noted on the initial (0 to 5 min) postexercise views. The rapid differential washout with teboroxime has not been previously described and the possible clinical significance is discussed

  5. Echocardiographic anatomy of the mitral valve: a critical appraisal of 2-dimensional imaging protocols with a 3-dimensional perspective.

    Science.gov (United States)

    Mahmood, Feroze; Hess, Philip E; Matyal, Robina; Mackensen, G Burkhard; Wang, Angela; Qazi, Aisha; Panzica, Peter J; Lerner, Adam B; Maslow, Andrew

    2012-10-01

    To highlight the limitations of traditional 2-dimensional (2D) echocardiographic mitral valve (MV) examination methodologies, which do not account for patient-specific transesophageal echocardiographic (TEE) probe adjustments made during an actual clinical perioperative TEE examination. Institutional quality-improvement project. Tertiary care hospital. Attending anesthesiologists certified by the National Board of Echocardiography. Using the technique of multiplanar reformatting with 3-dimensional (3D) data, ambiguous 2D images of the MV were generated, which resembled standard midesophageal 2D views. Based on the 3D image, the MV scallops visualized in each 2D image were recognized exactly by the position of the scan plane. Twenty-three such 2D MV images were created in a presentation from the 3D datasets. Anesthesia staff members (n = 13) were invited to view the presentation based on the 2D images only and asked to identify the MV scallops. Their responses were scored as correct or incorrect based on the 3D image. The overall accuracy was 30.4% in identifying the MV scallops. The transcommissural view was identified correctly >90% of the time. The accuracy of the identification of A1, A3, P1, and P3 scallops was <50%. The accuracy of the identification of A2P2 scallops was ≥50%. In the absence of information on TEE probe adjustments performed to acquire a specific MV image, it is possible to misidentify the scallops. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Application of the No Action Level (NAL) protocol to correct for prostate motion based on electronic portal imaging of implanted markers

    International Nuclear Information System (INIS)

    Boer, Hans C.J. de; Os, Marjolein J.H. van; Jansen, Peter P.; Heijmen, Ben J.M.

    2005-01-01

    Purpose: To evaluate the efficacy of the No Action Level (NAL) off-line correction protocol in the reduction of systematic prostate displacements as determined from electronic portal images (EPI) using implanted markers. Methods and materials: Four platinum markers, two near the apex and two near the base of the prostate, were implanted for localization purposes in patients who received fractionated high dose rate brachytherapy. During the following course of 25 fractions of external beam radiotherapy, the position of each marker relative to the corresponding position in digitally reconstructed radiographs (DRRs) was measured in EPI in 15 patients for on average 17 fractions per patient. These marker positions yield the composite displacements due to both setup error and internal prostate motion, relative to the planning computed tomography scan. As the NAL protocol is highly effective in reducing systematic errors (recurring each fraction) due to setup inaccuracy alone, we investigated its efficacy in reducing systematic composite displacements. The analysis was performed for the center of mass (COM) of the four markers, as well as for the cranial and caudal markers separately. Furthermore, the impact of prostate rotation on the achieved positioning accuracy was determined. Results: In case of no setup corrections, the standard deviations of the systematic composite displacements of the COM were 3-4 mm in the craniocaudal and anterior-posterior directions, and 2 mm in the left-right direction. The corresponding SDs of the random displacements (interfraction fluctuations) were 2-3 mm in each direction. When applying a NAL protocol based on three initial treatment fractions, the SDs of the systematic COM displacements were reduced to 1-2 mm. Displacements at the cranial end of the prostate were slightly larger than at the caudal end, and quantitative analysis showed this originates from left-right axis rotations about the prostate apex. Further analysis revealed

  7. Dopamine transporter imaging with [I-123]IPT SPECT in normal controls and Parkinson's patients: Feasibility study of a simplified SPECT scan protocol

    International Nuclear Information System (INIS)

    Kim, H. J.; Bong, J. K.; Nam, K. P.; Yang, S. O.; Moon, D. H.; Ryu, J. S.; Lee, H. K.

    1997-01-01

    [I-123]IPT has been used to measure changes in dopamine trasnporters with Parkinson's patients (PP). However, 2 hrs of imaging time without movement of patient's head partially limits its widespread use in routine clinical SPECT protocol. The purpose of this study was to evaluate the feasibility of a simplified IPT SPECT scan protocol using three 10 min scan data obtained at 0-10, 55-65, and 110-120 min postinjection and compared to current protocol using 23 scans obtained from O-120 min to quantify dopamine transporter binding in normal controls (NC) and PP. IPT labeled with 6.74±0.88mCi of I-123 was intravenously injected into 12 NC (age: 41±9) and 22 PP (age : 55±8) and the 5 min dynamic SPECT data were acquired for 2 hrs with Trionix triple-headed SPECT camera. SPECT images were reconstructed and attenuation corrected. [I-123] IPT quickly penetratd the blood-brain barrier and began to Ioacalize higher concentrations at the basal ganglia at 20 min after injection. The transporter parameter was measured using a variation of graphical analysis (VGA) and area ratio method (ARM) that derive the distribution volume ratios (R v =V 3 /V 2 for VGA, R A =V 3 /V 2 for ARM ) from multiple scan data without blood data, R v ' and R A ' measured from three 10 min scan data and compared with R v and R A measured from 23 scans for both NC and PP, (R v ', R v ') or NC and PP were (1.83±0.29, 2.21±0.34) and (0.63±0.34, 0.77±0.31), respectively. (R v ', R A ) for NC and PP were (1.11±0.22, 1.62±0.28) and (0.43±0.21, 0.65±0.24), respectively, Both (R v ', R v ) and (R A ', R A ) for NC were clearly separated from those for PP. R' v and R' A underestimated R v and R A by 18.4% and 33.5%, respectively, but R v ' and R A ' showed excellent correlations with R v (r=0.95) and R A (r=0.97), respectively. The results indicate that the three 10 min scan protocol may be feasible and allows us to differentiate dopamine transporter parameters in PP from those in NC

  8. Rapid magnetic resonance imaging protocol for detecting femoral head avascular necrosis: A case series-it′s utility in the general population in developing countries

    Directory of Open Access Journals (Sweden)

    M Sanjay Khaladkar

    2015-01-01

    Full Text Available Introduction: Osteonecrosis of the femoral head is an increasing cause of musculoskeletal disability, common among the younger population, between the third and fifth decade of life, affecting mainly men, thereby requiring prompt diagnosis and early intervention. Aims and Objectives: The aim was to formulate a limited magnetic resonance imaging (MRI examination protocol for detection of avascular necrosis (AVN in clinically suspected cases that can be performed rapidly and will be inexpensive. Materials and Methods: Forty-five patients suspected clinically and or on conventional radiography for AVN of the femoral head were referred for MRI hip. MRI hip was done on 1.5 T Siemens Avanto. Of 45, 36 were detected to have AVN (total 58 hips, whereas 9 did not have AVN on MRI. Initially, coronal T1-weighted image (T1WI sequence was obtained as limited MRI protocol, followed by complete MRI examination. Results: Maximum patients belonged to age group 31-40 (30.5%. 32 (88.88% patients were males and 4 (11.11% were females. Bilateral AVN was detected in 44 (61.1% and unilateral in 14 patients (38.8%. Pre collapsed stage (Stages I and II was detected in 18 hips (31.03%, collapsed stage (Stages III and IV was detected in 40 hips (68.9%. Peripheral low-intensity rim was seen on T1WI in all 58 cases of AVN. Double line sign on T2-weighted image was seen in 33/58 (56.8%. Conclusion: Our study concluded that coronal T1W sequence is an easy, rapid and cost-effective method of detecting unilateral or bilateral AVN.

  9. Stress perfusion magnetic resonance imaging to detect coronary artery lesions in children.

    Science.gov (United States)

    Vijarnsorn, Chodchanok; Noga, Michelle; Schantz, Daryl; Pepelassis, Dion; Tham, Edythe B

    2017-05-01

    Stress perfusion cardiovascular magnetic resonance (CMR) is used widely in adult ischemic heart disease, but data in children is limited. We sought to evaluate feasibility, accuracy and prognostic value of stress CMR in children with suspected coronary artery disease (CAD). Stress CMR was reviewed from two pediatric centers over 5 years using a standard pharmacologic protocol. Wall motion abnormalities, perfusion deficits and late enhancement were correlated with coronary angiogram (CAG) when available, and clinical status at 1 year follow-up for major adverse cardiovascular events (MACE; coronary revascularization, non-fatal myocardial infarction and death due to CAD) was recorded. Sixty-four stress perfusion CMR studies in 48 children (10.9 ± 4.8 years) using adenosine; 59 (92%) and dipyridamole; 5 (8%), were reviewed. Indications were Kawasaki disease (39%), post arterial switch operation (12.5%), post heart transplantation (12.5%), post anomalous coronary artery repair (11%), chest pain (11%), suspected myocarditis or CAD (3%), post coronary revascularization (3%), and others (8%). Twenty-six studies were performed under sedation. Of all studies performed, 66% showed no evidence of ischemia or infarction, 28% had perfusion deficits and 6% had late gadolinium enhancement (LGE) without perfusion deficit. Compared to CAG, the positive predictive value (PPV) of stress CMR was 80% with negative predictive value (NPV) of 88%. At 1 year clinical follow-up, the PPV and NPV of stress CMR to predict MACE were 78 and 98%. Stress-perfusion CMR, in combination with LGE and wall motion-analysis is a feasible and an accurate method of diagnosing CAD in children. In difficult cases, it also helps guide clinical intervention by complementing conventional CAG with functional information.

  10. Comprehensive low-dose imaging of carotid and coronary arteries with a single-injection dual-source CT angiography protocol.

    Science.gov (United States)

    Tognolini, A; Arellano, C S; Marfori, W; Heidari, G; Sayre, J W; Krishnam, M S; Ruehm, S G

    2014-03-01

    To assess the feasibility of a fast single-bolus combined carotid and coronary computed tomography angiography (CTA) protocol in asymptomatic patients. Thirty-three consecutive patients (18 women and 15 men) with a median age of 61 ± 14 years old (range 37-87 years) with known or suspected atherosclerotic disease were enrolled in this prospective study. A single breath-hold, single biphasic injection protocol (50 ml at 3 ml/s, 50 ml at 5 ml/s, 50 ml saline flush at 5 ml/s) was used for combined CTA imaging of the supra-aortic (SAA) and coronary arteries (CA) on a 64-slice dual-source CT (DSCT) machine. Helical CTA acquisition of the SAA was followed by prospective electrocardiography (ECG)-triggered coronary CTA. Subjective (four-point scale) image quality and objective signal-to-noise (SNR) and contrast-to-noise (CNR) measurements were performed. Vascular disease was graded on a four-point scale (grade 1: absent; grade 2: mild, grade 3: moderate; grade 4: severe). The radiation dose was recorded for each patient. The average enhancement and subjective quality score of SAA and CA segments were 396 HU/358 HU and 1.2 ± 0.3/1.72 ± 0.4, respectively. The SNR was 27.1 ± 1.7 in the SAA and 21.6 ± 1.6 in the CA (p grade 2 and 1/33 (3%) had grade 3 disease. CA findings were as follows: 25/33 (76%) showed no disease and 6/33 (18%) patients had grade 2 and 2/33 (6%) had grade 3 disease. Five patients had disease in both districts. The average radiation dose for the combined CTA angiogram was 4.3 ± 0.6 mSv. A fast, low-dose combined DSCT angiography protocol appears technically feasible for imaging carotid and coronary atherosclerotic disease. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  11. Paired-agent fluorescent imaging to detect micrometastases in breast sentinel lymph node biopsy: experiment design and protocol development

    Science.gov (United States)

    Li, Chengyue; Xu, Xiaochun; Basheer, Yusairah; He, Yusheng; Sattar, Husain A.; Brankov, Jovan G.; Tichauer, Kenneth M.

    2018-02-01

    Sentinel lymph node status is a critical prognostic factor in breast cancer treatment and is essential to guide future adjuvant treatment. The estimation that 20-60% of micrometastases are missed by conventional pathology has created a demand for the development of more accurate approaches. Here, a paired-agent imaging approach is presented that employs a control imaging agent to allow rapid, quantitative mapping of microscopic populations of tumor cells in lymph nodes to guide pathology sectioning. To test the feasibility of this approach to identify micrometastases, healthy pig lymph nodes were stained with targeted and control imaging agent solution to evaluate the potential for the agents to diffuse into and out of intact nodes. Aby-029, an anti-EGFR affibody was labeled with IRDye 800CW (LICOR) as targeted agent and IRDye 700DX was hydrolyzed as a control agent. Lymph nodes were stained and rinsed by directly injecting the agents into the lymph nodes after immobilization in agarose gel. Subsequently, lymph nodes were frozen-sectioned and imaged under an 80-um resolution fluorescence imaging system (Pearl, LICOR) to confirm equivalence of spatial distribution of both agents in the entire node. The binding potentials were acquired by a pixel-by-pixel calculation and was found to be 0.02 +/- 0.06 along the lymph node in the absence of binding. The results demonstrate this approach's potential to enhance the sensitivity of lymph node pathology by detecting fewer than 1000 cell in a whole human lymph node.

  12. Quantitative and qualitative comparison of MR imaging of the temporomandibular joint at 1.5 and 3.0 T using an optimized high-resolution protocol

    Science.gov (United States)

    Spinner, Georg; Wyss, Michael; Erni, Stefan; Ettlin, Dominik A; Nanz, Daniel; Ulbrich, Erika J; Gallo, Luigi M; Andreisek, Gustav

    2016-01-01

    Objectives: To quantitatively and qualitatively compare MRI of the temporomandibular joint (TMJ) using an optimized high-resolution protocol at 3.0 T and a clinical standard protocol at 1.5 T. Methods: A phantom and 12 asymptomatic volunteers were MR imaged using a 2-channel surface coil (standard TMJ coil) at 1.5 and 3.0 T (Philips Achieva and Philips Ingenia, respectively; Philips Healthcare, Best, Netherlands). Imaging protocol consisted of coronal and oblique sagittal proton density-weighted turbo spin echo sequences. For quantitative evaluation, a spherical phantom was imaged. Signal-to-noise ratio (SNR) maps were calculated on a voxelwise basis. For qualitative evaluation, all volunteers underwent MRI of the TMJ with the jaw in closed position. Two readers independently assessed visibility and delineation of anatomical structures of the TMJ and overall image quality on a 5-point Likert scale. Quantitative and qualitative measurements were compared between field strengths. Results: The quantitative analysis showed similar SNR for the high-resolution protocol at 3.0 T compared with the clinical protocol at 1.5 T. The qualitative analysis showed significantly better visibility and delineation of clinically relevant anatomical structures of the TMJ, including the TMJ disc and pterygoid muscle as well as better overall image quality at 3.0 T than at 1.5 T. Conclusions: The presented results indicate that expected gains in SNR at 3.0 T can be used to increase the spatial resolution when imaging the TMJ, which translates into increased visibility and delineation of anatomical structures of the TMJ. Therefore, imaging at 3.0 T should be preferred over 1.5 T for imaging the TMJ. PMID:26371077

  13. Quantitative and qualitative comparison of MR imaging of the temporomandibular joint at 1.5 and 3.0 T using an optimized high-resolution protocol.

    Science.gov (United States)

    Manoliu, Andrei; Spinner, Georg; Wyss, Michael; Erni, Stefan; Ettlin, Dominik A; Nanz, Daniel; Ulbrich, Erika J; Gallo, Luigi M; Andreisek, Gustav

    2016-01-01

    To quantitatively and qualitatively compare MRI of the temporomandibular joint (TMJ) using an optimized high-resolution protocol at 3.0 T and a clinical standard protocol at 1.5 T. A phantom and 12 asymptomatic volunteers were MR imaged using a 2-channel surface coil (standard TMJ coil) at 1.5 and 3.0 T (Philips Achieva and Philips Ingenia, respectively; Philips Healthcare, Best, Netherlands). Imaging protocol consisted of coronal and oblique sagittal proton density-weighted turbo spin echo sequences. For quantitative evaluation, a spherical phantom was imaged. Signal-to-noise ratio (SNR) maps were calculated on a voxelwise basis. For qualitative evaluation, all volunteers underwent MRI of the TMJ with the jaw in closed position. Two readers independently assessed visibility and delineation of anatomical structures of the TMJ and overall image quality on a 5-point Likert scale. Quantitative and qualitative measurements were compared between field strengths. The quantitative analysis showed similar SNR for the high-resolution protocol at 3.0 T compared with the clinical protocol at 1.5 T. The qualitative analysis showed significantly better visibility and delineation of clinically relevant anatomical structures of the TMJ, including the TMJ disc and pterygoid muscle as well as better overall image quality at 3.0 T than at 1.5 T. The presented results indicate that expected gains in SNR at 3.0 T can be used to increase the spatial resolution when imaging the TMJ, which translates into increased visibility and delineation of anatomical structures of the TMJ. Therefore, imaging at 3.0 T should be preferred over 1.5 T for imaging the TMJ.

  14. Thickness dependent properties of CMR Manganite thin films on lattice mismatched substrates: Distinguishing Strain and Interface Effects

    Science.gov (United States)

    Davidson, Anthony, III; Kolagani, Rajeswari; Bacharova, Ellisaveta; Yong, Grace; Smolyaninova, Vera; Schaefer, David; Mundle, Rajeh

    2007-03-01

    Epitaxial thin films of CMR manganite materials have been known to show thickness dependent electrical and magnetic properties on lattice mismatched substrates. Below a critical thickness, insulator-metal transition is suppressed. These effects have been largely attributed to the role of bi-axial lattice mismatch strain. Our recent results of epitaxial thin films of La0.67Ca0.33MnO3 (LCMO) on two substrates with varying degrees of compressive lattice mismatch indicate that, in addition to the effect of lattice mismatch strain, the thickness dependence of the properties are influenced by other factors possibly related to the nature of the film substrate interface and defects such as twin boundaries. We have compared the properties of LCMO films on (100) oriented LaAlO3 and (001) oriented NdCaAlO4 both of which induce compressive bi-axial strain. Interestingly, the suppression of the insulator-metal transition is less in films on NCAO which has a larger lattice mismatch. We will present results correlating the electrical and magneto transport properties with the structure and morphology of the films.

  15. RV Fractional Area Change and TAPSE as Predictors of Severe Right Ventricular Dysfunction in Pulmonary Hypertension: A CMR Study.

    Science.gov (United States)

    Hoette, Susana; Creuzé, Nicolas; Günther, Sven; Montani, David; Savale, Laurent; Jaïs, Xavier; Parent, Florence; Sitbon, Olivier; Rochitte, Carlos Eduardo; Simonneau, Gerald; Humbert, Marc; Souza, Rogerio; Chemla, Denis

    2018-04-01

    The right ventricular ejection fraction (RVEF) is a surrogate marker of right ventricular function in pulmonary hypertension (PH), but its measurement is complicated and time consuming. The tricuspid annular plane systolic excursion (TAPSE) measures only the longitudinal component of RV contraction while the right ventricular fractional area change (RVFAC) takes into account both the longitudinal and the transversal components. The aim of our study was to evaluate the relationship between RVEF, RVFAC, and TAPSE according to hemodynamic severity in two groups of patients with PH: pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Fifty-four patients with PAH (n = 15) and CTEPH (n = 39) underwent right heart catheterization and cardiac magnetic resonance (CMR). The ventricular volumes and areas, TAPSE, and eccentricity index were measured. The RVFAC was more strongly correlated with the RVEF (r = 0.81, p good index to estimate RVEF in PH patients; even better than the TAPSE in patients with more severe hemodynamic profile, possibly for including the transversal component of right ventricular function in its measurement. Furthermore, RVFAC performance was similar in the two PH groups (PAH and CTEPH).

  16. A Novel Morphometry-Based Protocol of Automated Video-Image Analysis for Species Recognition and Activity Rhythms Monitoring in Deep-Sea Fauna

    Directory of Open Access Journals (Sweden)

    Paolo Menesatti

    2009-10-01

    Full Text Available The understanding of ecosystem dynamics in deep-sea areas is to date limited by technical constraints on sampling repetition. We have elaborated a morphometry-based protocol for automated video-image analysis where animal movement tracking (by frame subtraction is accompanied by species identification from animals’ outlines by Fourier Descriptors and Standard K-Nearest Neighbours methods. One-week footage from a permanent video-station located at 1,100 m depth in Sagami Bay (Central Japan was analysed. Out of 150,000 frames (1 per 4 s, a subset of 10.000 was analyzed by a trained operator to increase the efficiency of the automated procedure. Error estimation of the automated and trained operator procedure was computed as a measure of protocol performance. Three displacing species were identified as the most recurrent: Zoarcid fishes (eelpouts, red crabs (Paralomis multispina, and snails (Buccinum soyomaruae. Species identification with KNN thresholding produced better results in automated motion detection. Results were discussed assuming that the technological bottleneck is to date deeply conditioning the exploration of the deep-sea.

  17. An image registration protocol to integrate electrophysiology, MRI and neuropathology data in epileptic patients explored with intracerebral electrodes.

    Science.gov (United States)

    Zucca, Ileana; Milesi, Gloria; Padelli, Francesco; Rossini, Laura; Gozzo, Francesca; Figini, Matteo; Barbaglia, Andrea; Cardinale, Francesco; Tassi, Laura; Bruzzone, Maria Grazia; Spreafico, Roberto; Garbelli, Rita

    2018-06-01

    Several attempts have been made to coregister in vivo MRI with the histopathology of surgical samples, aiming to validate new MRI biomarkers and improve the detection of epileptogenic lesions. As a further implementation, we propose a method to reconstruct the anatomical localization of the intracerebral electrodes on the histological sections, developing a coregistration protocol to match the in vivo MRI onto the ex vivo MRI obtained from the surgical specimen. Since the ex vivo MRI is natively in geometrical correspondence with histology slices, the goal of the coregistration process is to compute the transform function mapping the clinical MRI space to the ex vivo MRI. Electrodes and leads, identified in CT-MRI, can then be segmented and translated onto the histological slices. Step-by-step, qualitative visual inspection showed an improved matching of the anatomical structures or boundaries and electrodes positions between the two modalities. The quantitative evaluation of the coregistration protocol reported a mean error ranging between 0.82 and 1.27 mm when a sufficient number of landmarks, particularly in the core of the specimen, were clearly identified. Because histology was performed according to ex vivo MRI geometry we chose to transform the in vivo onto the ex vivo MRI, differently from other methods. Interesting applications of the method will include correlating the locally-generated pathological electrical activity with the subtle morphological alterations of the tissue, and histologically validating the origin of signal alterations or quantitative parameter variations in MRI studies. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Routine chest and abdominal high-pitch CT: An alternative low dose protocol with preserved image quality

    International Nuclear Information System (INIS)

    Amacker, Nadja A.; Mader, Caecilia; Alkadhi, Hatem; Leschka, Sebastian; Frauenfelder, Thomas

    2012-01-01

    Objective: To investigate the radiation dose and image quality of the high-pitch dual source computer tomography (DSCT) for routine chest and abdominal scans. Methods: 130 consecutive patients (62 female, 68 male, median age 55 years) were included. All patients underwent 128-slice high-pitch DSCT (chest n = 99; abdomen n = 84) at a pitch of 3.2. Two observers independently rated image quality using a 4-point score (1: excellent to 4: non-diagnostic). Image noise was measured and operational radiation dose quantities were recorded. An additional group of 132 patients (chest, n = 80; abdomen n = 52) scanned with standard-pitch CT matched for age, gender, and body mass index (BMI) served as control group. Results: Interobserver agreement for image quality rating was good (k = 0.74). Subjective image quality of high-pitch CT was diagnostic in all patients (median score chest; 2, median score abdomen: 2). Image noise of high-pitch CT was comparable to standard-pitch for the chest (p = 0.32) but increased in the abdomen (p < 0.0001). For high-pitch CT radiation dose was 4.4 ± 0.9 mSv (chest) and 6.5 ± 1.2 mSv (abdomen). These values were significantly lower compared to standard-pitch CT (chest: 5.5 ± 1.2 mSv; abdomen: 11.3 ± 3.8 mSv). Conclusion: Based on the technical background high-pitch dual source CT may serve as an alternative scan mode for low radiation dose routine chest and abdominal CT.

  19. Assessment of left atrial volume and function: a comparative study between echocardiography, magnetic resonance imaging and multi slice computed tomography.

    Science.gov (United States)

    Kühl, J Tobias; Lønborg, Jacob; Fuchs, Andreas; Andersen, Mads J; Vejlstrup, Niels; Kelbæk, Henning; Engstrøm, Thomas; Møller, Jacob E; Kofoed, Klaus F

    2012-06-01

    Measurement of left atrial (LA) maximal volume (LA(max)) using two-dimensional transthoracic echocardiography (TTE) provides prognostic information in several cardiac diseases. However, the relationship between LA(max) and LA function is poorly understood and TTE is less well suited for measuring dynamic LA volume changes. Conversely, cardiac magnetic resonance imaging (CMR) and multi-slice computed tomography (MSCT) appears more appropriate for such measures. We sought to determine the relationship between LA size assessed with TTE and LA size and function assessed with CMR and MSCT. Fifty-four patients were examined 3 months post myocardial infarction with echocardiography, CMR and MSCT. Left atrial volumes and LA reservoir function were assessed by TTE. LA time-volume curves were determined and LA reservoir function (cyclic change and fractional change), passive emptying function (reservoir volume) and pump function (left atrial ejection fraction-LAEF) were derived using CMR and MSCT. Left atrial fractional change and left atrial ejection fraction (LAEF) determined with CMR and MSCT were unrelated to LA(max) enlargement by echocardiography (P = NS). There was an overall good agreement between CMR and MSCT, with a small to moderate bias in LA(max) (4.9 ± 10.4 ml), CC (3.1 ± 9.1 ml) and reservoir volume (3.4 ± 9.1 ml). TTE underestimates LA(max) with up to 32% compared with CMR and MSCT (P fractional change and LAEF is not significantly related to LA(max) measured by TTE. TTE systematically underestimated LA volumes, whereas there are good agreements between MSCT and CMR for volumetric and functional properties.

  20. Myocardial Fibrosis in Competitive Triathletes Detected by Contrast-Enhanced CMR Correlates With Exercise-Induced Hypertension and Competition History.

    Science.gov (United States)

    Tahir, Enver; Starekova, Jitka; Muellerleile, Kai; von Stritzky, Alexandra; Münch, Julia; Avanesov, Maxim; Weinrich, Julius M; Stehning, Christian; Bohnen, Sebastian; Radunski, Ulf K; Freiwald, Eric; Blankenberg, Stefan; Adam, Gerhard; Pressler, Axel; Patten, Monica; Lund, Gunnar K

    2017-12-08

    This study analyzed the presence of myocardial fibrosis detected by late gadolinium-enhancement (LGE) cardiac magnetic resonance (CMR) in correlation with the performance of competitive triathletes objectified by an exercise test and individual competition history. Myocardial fibrosis detected by LGE CMR has been reported to occur in 0% to 50% of asymptomatic athletes. However, the cause and mechanisms of myocardial fibrosis are unclear. Eighty-three asymptomatic triathletes undergoing >10 training h per week (43 ± 10 years of age; 65% male) and 36 sedentary controls were studied by using LGE and extracellular volume (ECV) CMR. Parameters of physical fitness were measured by spiroergometry. Triathletes reported their lifetime competition results. LGE CMR revealed focal nonischemic myocardial fibrosis in 9 of 54 (17%) male triathletes (LGE + ) but in none of the female triathletes (p pressure (213 ± 24 mm Hg) than LGE - triathletes (194 ± 26 mm Hg; p 1,880 km completed during competition had the highest accuracy to predict LGE, with an area under the curve value of 0.876 (p pressure (p < 0.05) and the swimming race distance (p < 0.01) as independent predictors of LGE presence. Myocardial fibrosis in asymptomatic triathletes seems to be associated with exercise-induced hypertension and the race distances. There appears to be a safe upper limit, beyond which exercise may result in myocardial fibrosis. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  1. Imaging Protocols in Clinical Studies in Advanced Age-Related Macular Degeneration: Recommendations from Classification of Atrophy Consensus Meetings

    NARCIS (Netherlands)

    Holz, F.G.; Sadda, S.R.; Staurenghi, G.; Lindner, M.; Bird, A.C.; Blodi, B.A.; Bottoni, F.; Chakravarthy, U.; Chew, E.Y.; Csaky, K.; Curcio, C.A.; Danis, R.; Fleckenstein, M.; Freund, K.B.; Grunwald, J.; Guymer, R.; Hoyng, C.B.; Jaffe, G.J.; Liakopoulos, S.; Mones, J.M.; Oishi, A.; Pauleikhoff, D.; Rosenfeld, P.J.; Sarraf, D.; Spaide, R.F.; Tadayoni, R.; Tufail, A.; Wolf, S.; Schmitz-Valckenberg, S.

    2017-01-01

    PURPOSE: To summarize the results of 2 consensus meetings (Classification of Atrophy Meeting [CAM]) on conventional and advanced imaging modalities used to detect and quantify atrophy due to late-stage non-neovascular and neovascular age-related macular degeneration (AMD) and to provide

  2. Diagnostic accuracy of cardiovascular magnetic resonance imaging of right ventricular morphology and function in the assessment of suspected pulmonary hypertension results from the ASPIRE registry

    Directory of Open Access Journals (Sweden)

    Swift Andrew J

    2012-06-01

    Full Text Available Abstract Background Cardiovascular Magnetic Resonance (CMR imaging is accurate and reproducible for the assessment of right ventricular (RV morphology and function. However, the diagnostic accuracy of CMR derived RV measurements for the detection of pulmonary hypertension (PH in the assessment of patients with suspected PH in the clinic setting is not well described. Methods We retrospectively studied 233 consecutive treatment naïve patients with suspected PH including 39 patients with no PH who underwent CMR and right heart catheterisation (RHC within 48hours. The diagnostic accuracy of multiple CMR measurements for the detection of mPAP ≥ 25 mmHg was assessed using Fisher’s exact test and receiver operating characteristic (ROC analysis. Results Ventricular mass index (VMI was the CMR measurement with the strongest correlation with mPAP (r = 0.78 and the highest diagnostic accuracy for the detection of PH (area under the ROC curve of 0.91 compared to an ROC of 0.88 for echocardiography calculated mPAP. Late gadolinium enhancement, VMI ≥ 0.4, retrograde flow ≥ 0.3 L/min/m2 and PA relative area change ≤ 15% predicted the presence of PH with a high degree of diagnostic certainty with a positive predictive value of 98%, 97%, 95% and 94% respectively. No single CMR parameter could confidently exclude the presence of PH. Conclusion CMR is a useful alternative to echocardiography in the evaluation of suspected PH. This study supports a role for the routine measurement of ventricular mass index, late gadolinium enhancement and the use of phase contrast imaging in addition to right heart functional indices in patients undergoing diagnostic CMR evaluation for suspected pulmonary hypertension.

  3. Radiolabeled annexin V for imaging apoptosis in radiated human follicular thyroid carcinomas - is an individualized protocol necessary?

    Energy Technology Data Exchange (ETDEWEB)

    Grosse, Jirka [Department of Nuclear Medicine, University of Regensburg, 93042 Regensburg (Germany); Department of Clinical Pharmacology and Toxicology, Charite-Universitaetsmedizin Berlin, Campus Benjamin Franklin, 14195 Berlin (Germany)], E-mail: jirka.grosse@klinik.uni-regensburg.de; Grimm, Daniela [Department of Clinical Pharmacology and Toxicology, Charite-Universitaetsmedizin Berlin, Campus Benjamin Franklin, 14195 Berlin (Germany); Department of Pharmacology, University of Aarhus, 8000 Aarhus (Denmark); Westphal, Kriss; Ulbrich, Claudia [Department of Clinical Pharmacology and Toxicology, Charite-Universitaetsmedizin Berlin, Campus Benjamin Franklin, 14195 Berlin (Germany); Moosbauer, Jutta [Department of Nuclear Medicine, University of Regensburg, 93042 Regensburg (Germany); Pohl, Fabian; Koelbl, Oliver [Department of Radiooncology, University of Regensburg, 93042 Regensburg (Germany); Infanger, Manfred [Department of Reconstructive Surgery, Charite-Universitaetsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin (Germany); Eilles, Christoph; Schoenberger, Johann [Department of Nuclear Medicine, University of Regensburg, 93042 Regensburg (Germany)

    2009-01-15

    Introduction: Induction of apoptosis is a widely used strategy for cancer therapy, but evaluating the degree and success of this therapy still poses a problem. Radiolabeled annexin V has been proposed to be a promising candidate for detecting apoptotic cells in tumors following chemotherapy in vivo. In order to see whether radiolabeled annexin V could be a suitable substance for the noninvasive in vivo detection of apoptosis in thyroid tissue and to establish an optimized study protocol, we investigated two poorly differentiated thyroid carcinoma cell lines: ML-1 and FTC-133. Methods: Apoptosis was evaluated before as well as 2 and 4 days after in vitro irradiation with 30 Gy X-rays. In this study, binding of FITC- and of {sup 125}I-labeled annexin V was measured in comparison to other apoptosis markers such as Bax, caspase-3 and Fas, which were determined by flow cytometry and Western blot analysis with densitometric evaluation. Results: ML-1 and FTC-133 cells showed a significant increase in annexin V binding 48 h after irradiation. Ninety-six hours after irradiation, the annexin V absorption capability of ML-1 cells was still maximal, while the living fraction of FTC-133 increased significantly. The amount of caspase-3 and Bax was clearly increased 48 h after irradiation and had normalized after 96 h in both cell lines. Fas protein concentrations remained unchanged in ML-1 cells but were significantly enhanced in FTC-133 cells. Conclusion: The binding of FITC- and {sup 125}I-labeled annexin V showed a significant accordance. A reliable evaluation of apoptosis induced by radiotherapy in thyroid tumors was possible 48 h after irradiation, when binding of radiolabeled annexin V is most significantly enhanced. Using two poorly differentiated cell lines of thyroid carcinoma, one may expect to find a nearly similar response to external irradiation. In contrast, the cell lines showed a completely contrary response. However, an individualized study protocol for each

  4. Clinician, patient and general public beliefs about diagnostic imaging for low back pain: protocol for a qualitative evidence synthesis.

    Science.gov (United States)

    Traeger, Adrian C; Reed, Benjamin J; O'Connor, Denise A; Hoffmann, Tammy C; Machado, Gustavo C; Bonner, Carissa; Maher, Chris G; Buchbinder, Rachelle

    2018-02-10

    Little is known about how to reduce unnecessary imaging for low back pain. Understanding clinician, patient and general public beliefs about imaging is critical to developing strategies to reduce overuse. To synthesise qualitative research that has explored clinician, patient or general public beliefs about diagnostic imaging for low back pain. We will perform a qualitative evidence synthesis of relevant qualitative research exploring clinician, patient and general public beliefs about diagnostic imaging for low back pain. Exclusions will be studies not using qualitative methods and studies not published in English. Studies will be identified using sensitive search strategies in MEDLINE, EMBASE, CINAHL, AMED and PsycINFO. Two reviewers will independently apply inclusion and exclusion criteria, extract data, and use the Critical Appraisal Skills Programme quality assessment tool to assess the quality of included studies. To synthesise the data we will use a narrative synthesis approach that involves developing a theoretical model, conducting a preliminary synthesis, exploring relations in the data, and providing a structured summary. We will code the data using NVivo. At least two reviewers will independently apply the thematic framework to extracted data. Confidence in synthesis findings will be evaluated using the GRADE Confidence in the Evidence from Reviews of Qualitative Research tool. Ethical approval is not required to conduct this review. We will publish the results in a peer-reviewed journal. CRD42017076047. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. The challenge of on-tissue digestion for MALDI MSI- a comparison of different protocols to improve imaging experiments.

    Science.gov (United States)

    Diehl, Hanna C; Beine, Birte; Elm, Julian; Trede, Dennis; Ahrens, Maike; Eisenacher, Martin; Marcus, Katrin; Meyer, Helmut E; Henkel, Corinna

    2015-03-01

    Mass spectrometry imaging (MSI) has become a powerful and successful tool in the context of biomarker detection especially in recent years. This emerging technique is based on the combination of histological information of a tissue and its corresponding spatial resolved mass spectrometric information. The identification of differentially expressed protein peaks between samples is still the method's bottleneck. Therefore, peptide MSI compared to protein MSI is closer to the final goal of identification since peptides are easier to measure than proteins. Nevertheless, the processing of peptide imaging samples is challenging due to experimental complexity. To address this issue, a method development study for peptide MSI using cryoconserved and formalin-fixed paraffin-embedded (FFPE) rat brain tissue is provided. Different digestion times, matrices, and proteases were tested to define an optimal workflow for peptide MSI. All practical experiments were done in triplicates and analyzed by the SCiLS Lab software, using structures derived from myelin basic protein (MBP) peaks, principal component analysis (PCA) and probabilistic latent semantic analysis (pLSA) to rate the experiments' quality. Blinded experimental evaluation in case of defining countable structures in the datasets was performed by three individuals. Such an extensive method development for peptide matrix-assisted laser desorption/ionization (MALDI) imaging experiments has not been performed so far, and the resulting problems and consequences were analyzed and discussed.

  6. Cardiac magnetic resonance imaging in heart failure: where the alphabet begins!

    Science.gov (United States)

    Aljizeeri, Ahmed; Sulaiman, Abdulbaset; Alhulaimi, Naji; Alsaileek, Ahmed; Al-Mallah, Mouaz H

    2017-07-01

    Cardiac Magnetic Resonance Imaging has become a cornerstone in the evaluation of heart failure. It provides a comprehensive evaluation by answering all the pertinent clinical questions across the full pathological spectrum of heart failure. Nowadays, CMR is considered the gold standard in evaluation of ventricular volumes, wall motion and systolic function. Through its unique ability of tissue characterization, it provides incremental diagnostic and prognostic information and thus has emerged as a comprehensive imaging modality in heart failure. This review outlines the role of main conventional CMR sequences in the evaluation of heart failure and their impact in the management and prognosis.

  7. The Norwegian healthy body image programme: study protocol for a randomized controlled school-based intervention to promote positive body image and prevent disordered eating among Norwegian high school students.

    Science.gov (United States)

    Sundgot-Borgen, Christine; Bratland-Sanda, Solfrid; Engen, Kethe M E; Pettersen, Gunn; Friborg, Oddgeir; Torstveit, Monica Klungland; Kolle, Elin; Piran, Niva; Sundgot-Borgen, Jorunn; Rosenvinge, Jan H

    2018-03-06

    Body dissatisfaction and disordered eating raise the risk for eating disorders. In the prevention of eating disorders, many programmes have proved partly successful in using cognitive techniques to combat such risk factors. However, specific strategies to actively promote a positive body image are rarely used. The present paper outlines a protocol for a programme integrating the promotion of a positive body image and the prevention of disordered eating. Using a cluster randomized controlled mixed methods design, 30 high schools and 2481 12th grade students were allocated to the Healthy Body Image programme or to a control condition. The intervention comprised three workshops, each of 90 min with the main themes body image, media literacy, and lifestyle. The intervention was interactive in nature, and were led by trained scientists. The outcome measures include standardized instruments administered pre-post intervention, and at 3 and 12 months follow-ups, respectively. Survey data cover feasibility and implementation issues. Qualitative interviews covers experiential data about students' benefits and satisfaction with the programme. The present study is one of the first in the body image and disordered eating literature that integrates a health promotion and a disease prevention approach, as well as integrating standardized outcome measures and experiential findings. Along with mediator and moderator analyses it is expected that the Healthy Body Image programme may prove its efficacy. If so, plans are made with respect to further dissemination as well as communicating the findings to regional and national decision makers in the education and health care services. The study was registered and released at ClinicalTrials.gov 21th August 2016 with the Clinical Trial.gov ID: PRSNCT02901457 . In addition, the study is approved by the Regional Committee for Medical and Health Research Ethics.

  8. Influence of bismuth shielding use in the dose CT and the imaging quality in standard brain protocol

    International Nuclear Information System (INIS)

    Sanchez Carnoma, G.; Urena Llinares, A.; Santos Rubio, A.; Haro Madero, G.; Herrador Cordoba, M.

    2006-01-01

    The purpose of this work is to evaluate the reduction of lens doses, CT dose index (CTDI) and image quality when bismuth shielding is used. Dose indexes nCDTIs,p, w were measured for a head phantom (d=16 cm) in three situations: first, without shielding, second, shielded with bismuth over the phantom surface and, last, with 2 cm between both. Four regions of interest were selected, two including the theoretical eyes position and the others 4-6 cm below them. Noise and grey level in Housfield units were also measured in all geometries. A bismuth shielding in contact or 2 cm above surface provides a dose reduction of 36% y 29% respectively. In the first case an importation of image quality appears, increasing a 55% the Housfield units in the superficial regions of interest and a growth of noise 6 times greater. Bismuth protection provides an important reduction in lens dose., in the case of dire ct incidence radiation beam. (Author)

  9. Phaedra, a protocol-driven system for analysis and validation of high-content imaging and flow cytometry.

    Science.gov (United States)

    Cornelissen, Frans; Cik, Miroslav; Gustin, Emmanuel

    2012-04-01

    High-content screening has brought new dimensions to cellular assays by generating rich data sets that characterize cell populations in great detail and detect subtle phenotypes. To derive relevant, reliable conclusions from these complex data, it is crucial to have informatics tools supporting quality control, data reduction, and data mining. These tools must reconcile the complexity of advanced analysis methods with the user-friendliness demanded by the user community. After review of existing applications, we realized the possibility of adding innovative new analysis options. Phaedra was developed to support workflows for drug screening and target discovery, interact with several laboratory information management systems, and process data generated by a range of techniques including high-content imaging, multicolor flow cytometry, and traditional high-throughput screening assays. The application is modular and flexible, with an interface that can be tuned to specific user roles. It offers user-friendly data visualization and reduction tools for HCS but also integrates Matlab for custom image analysis and the Konstanz Information Miner (KNIME) framework for data mining. Phaedra features efficient JPEG2000 compression and full drill-down functionality from dose-response curves down to individual cells, with exclusion and annotation options, cell classification, statistical quality controls, and reporting.

  10. Comparison of Placido disc and Scheimpflug image-derived topography-guided excimer laser surface normalization combined with higher fluence CXL: the Athens Protocol, in progressive keratoconus

    Directory of Open Access Journals (Sweden)

    Kanellopoulos AJ

    2013-07-01

    Full Text Available Anastasios John Kanellopoulos,1,2 George Asimellis11Laservision.gr Eye Institute, Athens, Greece; 2New York University School of Medicine, Department of Opthalmology, NY, NY, USABackground: The purpose of this study was to compare the safety and efficacy of two alternative corneal topography data sources used in topography-guided excimer laser normalization, combined with corneal collagen cross-linking in the management of keratoconus using the Athens protocol, ie, a Placido disc imaging device and a Scheimpflug imaging device.Methods: A total of 181 consecutive patients with keratoconus who underwent the Athens protocol between 2008 and 2011 were studied preoperatively and at months 1, 3, 6, and 12 postoperatively for visual acuity, keratometry, and anterior surface corneal irregularity indices. Two groups were formed, depending on the primary source used for topoguided photoablation, ie, group A (Placido disc and group B (Scheimpflug rotating camera. One-year changes in visual acuity, keratometry, and seven anterior surface corneal irregularity indices were studied in each group.Results: Changes in visual acuity, expressed as the difference between postoperative and preoperative corrected distance visual acuity were +0.12 ± 0.20 (range +0.60 to -0.45 for group A and +0.19 ± 0.20 (range +0.75 to -0.30 for group B. In group A, K1 (flat keratometry changed from 45.202 ± 3.782 D to 43.022 ± 3.819 D, indicating a flattening of -2.18 D, and K2 (steep keratometry changed from 48.670 ± 4.066 D to 45.865 ± 4.794 D, indicating a flattening of -2.805 D. In group B, K1 (flat keratometry changed from 46.213 ± 4.082 D to 43.190 ± 4.398 D, indicating a flattening of -3.023 D, and K2 (steep keratometry changed from 50.774 ± 5.210 D to 46.380 ± 5.006 D, indicating a flattening of -4.394 D. For group A, the index of surface variance decreased to -5.07% and the index of height decentration to -26.81%. In group B, the index of surface variance

  11. Use of cardiovascular magnetic resonance imaging for TAVR assessment in patients with bioprosthetic aortic valves: Comparison with computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Quail, Michael A., E-mail: m.quail@ucl.ac.uk [Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science and Great Ormond Street Hospital for Children, London (United Kingdom); Nordmeyer, Johannes [Department of Congenital Heart Disease and Paediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin (Germany); Schievano, Silvia [Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science and Great Ormond Street Hospital for Children, London (United Kingdom); Reinthaler, Markus; Mullen, Michael J. [The Heart Hospital, University College Hospital and Institute of Cardiovascular Sciences, UCL, 16-18 Westmoreland Street, London (United Kingdom); Taylor, Andrew M. [Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science and Great Ormond Street Hospital for Children, London (United Kingdom)

    2012-12-15

    Purpose: Transcatheter aortic valve replacement (TAVR) has been successfully used to treat patients with failing aortic bioprostheses. Computed tomography (CT) is the usual method of pre-procedural imaging for TAVR in the native position; however, the optimal modality for valve-in-valve procedures has not been established. CT can assess intracardiac anatomy and is superior to cardiovascular magnetic resonance (CMR) in the assessment of coronary artery disease. However, CMR can provide superior haemodynamic information, does not carry the risk of ionising radiation, and may be performed without contrast in patients with renal insufficiency. In this study, we compared CT and CMR for the evaluation of TAVR in a small cohort of patients with existing aortic bioprostheses. Materials and methods: 21 patients with aortic bioprostheses were prospectively evaluated by CT and CMR, as pre-assessment for TAVR; agreement between measurements of aortic geometries was assessed. Results: 16/21 patients had aortic bioprostheses constructed with a metal ring, and 5/21 patients had a metal strut construction. Patients with metal struts had significant metal-artefact on CMR, which compromised image quality in this region. There was good agreement between CT and CMR measurements of aortic geometry. The mean difference (d) in annulus area-derived diameter was 0.5 mm (95% limits of agreement [L.A] 4.2 mm). There was good agreement between modalities for the cross-sectional area of the sinuses of valsalva (d 0.5 cm{sup 2}, L.A 1.4 cm{sup 2}), sinotubular junction (d 0.9 cm{sup 2}, L.A 1.5 cm{sup 2}), and ascending aorta (d 0.6 cm{sup 2}, L.A 1.4 cm{sup 2}). In patients without metal struts, the left coronary artery height d was 0.7 mm and L.A 2.8 mm. Conclusions: Our analysis shows that CMR and CT measurements of aortic geometry show good agreement, including measurement of annulus size and coronary artery location, and thus provide the necessary anatomical information for valve

  12. Use of cardiovascular magnetic resonance imaging for TAVR assessment in patients with bioprosthetic aortic valves: Comparison with computed tomography

    International Nuclear Information System (INIS)

    Quail, Michael A.; Nordmeyer, Johannes; Schievano, Silvia; Reinthaler, Markus; Mullen, Michael J.; Taylor, Andrew M.

    2012-01-01

    Purpose: Transcatheter aortic valve replacement (TAVR) has been successfully used to treat patients with failing aortic bioprostheses. Computed tomography (CT) is the usual method of pre-procedural imaging for TAVR in the native position; however, the optimal modality for valve-in-valve procedures has not been established. CT can assess intracardiac anatomy and is superior to cardiovascular magnetic resonance (CMR) in the assessment of coronary artery disease. However, CMR can provide superior haemodynamic information, does not carry the risk of ionising radiation, and may be performed without contrast in patients with renal insufficiency. In this study, we compared CT and CMR for the evaluation of TAVR in a small cohort of patients with existing aortic bioprostheses. Materials and methods: 21 patients with aortic bioprostheses were prospectively evaluated by CT and CMR, as pre-assessment for TAVR; agreement between measurements of aortic geometries was assessed. Results: 16/21 patients had aortic bioprostheses constructed with a metal ring, and 5/21 patients had a metal strut construction. Patients with metal struts had significant metal-artefact on CMR, which compromised image quality in this region. There was good agreement between CT and CMR measurements of aortic geometry. The mean difference (d) in annulus area-derived diameter was 0.5 mm (95% limits of agreement [L.A] 4.2 mm). There was good agreement between modalities for the cross-sectional area of the sinuses of valsalva (d 0.5 cm 2 , L.A 1.4 cm 2 ), sinotubular junction (d 0.9 cm 2 , L.A 1.5 cm 2 ), and ascending aorta (d 0.6 cm 2 , L.A 1.4 cm 2 ). In patients without metal struts, the left coronary artery height d was 0.7 mm and L.A 2.8 mm. Conclusions: Our analysis shows that CMR and CT measurements of aortic geometry show good agreement, including measurement of annulus size and coronary artery location, and thus provide the necessary anatomical information for valve-in-valve TAVR planning. However

  13. Metabolic Tumor Volume as a Prognostic Imaging-Based Biomarker for Head-and-Neck Cancer: Pilot Results From Radiation Therapy Oncology Group Protocol 0522

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, David L., E-mail: david.schwartz@utsw.edu [Department of Radiation Oncology, University of Texas Southwestern School of Medicine, Dallas, Texas (United States); Harris, Jonathan [Radiation Therapy Oncology Group Statistical Center, Philadelphia, Pennsylvania (United States); Yao, Min [Department of Radiation Oncology, Case Western Reserve University School of Medicine, Cleveland, Ohio (United States); Rosenthal, David I. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Opanowski, Adam; Levering, Anthony [American College of Radiology Imaging Network, Philadelphia, Pennsylvania (United States); Ang, K. Kian [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Trotti, Andy M. [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida (United States); Garden, Adam S. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Jones, Christopher U. [Sutter Medical Group, Sacramento, California (United States); Harari, Paul [Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin (United States); Foote, Robert [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Holland, John [Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon (United States); Zhang, Qiang [Radiation Therapy Oncology Group Statistical Center, Philadelphia, Pennsylvania (United States); Le, Quynh-Thu [Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California (United States)

    2015-03-15

    Purpose: To evaluate candidate fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging biomarkers for head-and-neck chemoradiotherapy outcomes in the cooperative group trial setting. Methods and Materials: Radiation Therapy Oncology Group (RTOG) protocol 0522 patients consenting to a secondary FDG-PET/CT substudy were serially imaged at baseline and 8 weeks after radiation. Maximum standardized uptake value (SUVmax), SUV peak (mean SUV within a 1-cm sphere centered on SUVmax), and metabolic tumor volume (MTV) using 40% of SUVmax as threshold were obtained from primary tumor and involved nodes. Results: Of 940 patients entered onto RTOG 0522, 74 were analyzable for this substudy. Neither high baseline SUVmax nor SUVpeak from primary or nodal disease were associated with poor treatment outcomes. However, primary tumor MTV above the cohort median was associated with worse local-regional control (hazard ratio 4.01, 95% confidence interval 1.28-12.52, P=.02) and progression-free survival (hazard ratio 2.34, 95% confidence interval 1.02-5.37, P=.05). Although MTV and T stage seemed to correlate (mean MTV 6.4, 13.2, and 26.8 for T2, T3, and T4 tumors, respectively), MTV remained a strong independent prognostic factor for progression-free survival in bivariate analysis that included T stage. Primary MTV remained prognostic in p16-associated oropharyngeal cancer cases, although sample size was limited. Conclusion: High baseline primary tumor MTV was associated with worse treatment outcomes in this limited patient subset of RTOG 0522. Additional confirmatory work will be required to validate primary tumor MTV as a prognostic imaging biomarker for patient stratification in future trials.

  14. Protocol optimization of sacroiliac joint MR Imaging at 3 Tesla: Impact of coil design and motion resistant sequences on image quality.

    Science.gov (United States)

    Gondim Teixeira, P A; Bravetti, M; Hossu, G; Lecocq, S; Petit, D; Loeuille, D; Blum, A

    2017-12-01

    To evaluate the impact of coil design and motion-resistant sequences on the quality of sacroiliac magnetic resonance imaging (MRI) examination in patients with spondyloarthropathy. One hundred and twenty-one patients with suspected sacroiliitis and referred for MRI of the sacroiliac joints were retrospectively evaluated with MRI at 3-Tesla. There were 78 women and 43 men with a mean age of 36.7±11.5 (SD) years (range: 15.8-78.4 years). Conventional and motion-resistant fat-saturated fast-spin echo T2-weighted sequences were performed with two different coils. Image quality was subjectively evaluated by two independent readers (R1 and R2) using a four-point scale. Confidence in the identification of bone marrow edema pattern (BMEP) was also evaluated subjectively using a three-point scale. Phased array body coil yielded improved image quality compared to surface coil (14.1 to 30.4% for R1 and 14.6 to 25.7% for R2; Pcoil with motion-resistant T2-weighted sequence (kappa 0.990). The smallest number of indeterminate BMEP zones was seen on MRI set acquired with the phased-array body coil and motion-resistant T2-weighted sequence. Phased array body coil and motion-resistant T2-weighted sequences perform better than surface coil and conventional T2-weighted sequences for the evaluation of sacroiliac joints, increasing confidence in the identification of BMEP. Copyright © 2017 Editions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  15. Gated SPECT evaluation of left ventricular function using a CZT camera and a fast low-dose clinical protocol: comparison to cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Giorgetti, Assuero; Masci, Pier Giorgio; Marras, Gavino; Gimelli, Alessia; Genovesi, Dario; Lombardi, Massimo [Fondazione CNR/Regione Toscana ' ' G. Monasterio' ' , Pisa (Italy); Rustamova, Yasmine K. [Azerbaijan Medical University, Department of internal medicine Central Customs Hospital, Baku (Azerbaijan); Marzullo, Paolo [Istituto di Fisiologia Clinica del CNR, Pisa (Italy)

    2013-12-15

    CZT technology allows ultrafast low-dose myocardial scintigraphy but its accuracy in assessing left ventricular function is still to be defined. The study group comprised 55 patients (23 women, mean age 63 {+-} 9 years) referred for myocardial perfusion scintigraphy. The patients were studied at rest using a CZT camera (Discovery NM530c; GE Healthcare) and a low-dose {sup 99m}Tc-tetrofosmin clinical protocol (mean dose 264 {+-} 38 MBq). Gated SPECT imaging was performed as a 6-min list-mode acquisition, 15 min after radiotracer injection. Images were reformatted (8-frame to 16-frame) using Lister software on a Xeleris workstation (GE Healthcare) and then reconstructed with a dedicated iterative algorithm. Analysis was performed using Quantitative Gated SPECT (QGS) software. Within 2 weeks patients underwent cardiac magnetic resonance imaging (cMRI, 1.5-T unit CVi; GE Healthcare) using a 30-frame acquisition protocol and dedicated software for analysis (MASS 6.1; Medis). The ventricular volumes obtained with 8-frame QGS showed excellent correlations with the cMRI volumes (end-diastolic volume (EDV), r = 0.90; end-systolic volume (ESV), r = 0.94; p < 0.001). However, QGS significantly underestimated the ventricular volumes (mean differences: EDV, -39.5 {+-} 29 mL; ESV, -15.4 {+-} 22 mL; p < 0.001). Similarly, the ventricular volumes obtained with 16-frame QGS showed an excellent correlations with the cMRI volumes (EDV, r = 0.92; ESV, r = 0.95; p < 0.001) but with significant underestimations (mean differences: EDV, -33.2 {+-} 26 mL; ESV, -17.9 {+-} 20 mL; p < 0.001). Despite significantly lower values (47.9 {+-} 16 % vs. 51.2 {+-} 15 %, p < 0.008), 8-frame QGS mean ejection fraction (EF) was closely correlated with the cMRI values (r = 0.84, p < 0.001). The mean EF with 16-frame QGS showed the best correlation with the cMRI values (r = 0.91, p < 0.001) and was similar to the mean cMRI value (49.6 {+-} 16 %, p not significant). Regional analysis showed a good

  16. Clinical outcomes from an innovative protocol using serial ultrasound imaging and a single MR image to guide brachytherapy for locally advanced cervix cancer.

    Science.gov (United States)

    van Dyk, Sylvia; Narayan, Kailash; Bernshaw, David; Kondalsamy-Chennakesavan, Srinivas; Khaw, Pearly; Lin, Ming Yin; Schneider, Michal

    The aim of this study was to report clinical outcomes in a series of patients who underwent serial ultrasound and a single MRI to plan and verify intracavitary brachytherapy. Data for patients who were referred for curative intent radiotherapy for International Federation of Gynecology and Obstetrics (FIGO) Stage 1-1V cervix cancer between January 2007 and March 2012 were analyzed. All patients received external beam radiotherapy with concurrent chemotherapy and sequential high-dose rate brachytherapy. Brachytherapy was planned and verified using serial ultrasound imaging and a single MRI. Data from 191 patients were available for analyses. The median (range) followup time was 5.08 (0.25-8.25) years. Five-year local control, failure-free survival, cancer-specific survival, and overall survival were 86%, 57.3%, 70% and 63%, respectively. Mean (standard deviation) combined external beam radiotherapy and brachytherapy target doses, equivalent to doses in 2 Gy fractions were 80.4 Gy10 (3.89), median (range) 80 (49-96) Gy10. Grade 3 or greater gastrointestinal, genitourinary, or vaginal late toxicity occurred in 3%, 1.6%, and 2% of patients, respectively. Survival, patterns of failure, and late complication rates were similar to published series of MRI/CT-based brachytherapy practices. This large study demonstrates that favorable treatment outcomes can be obtained using a pragmatic and innovative combination of ultrasound and MR imaging. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  17. Evaluation of a low-carbohydrate diet-based preparation protocol without fasting for cardiac PET/MR imaging.

    Science.gov (United States)

    Nensa, Felix; Tezgah, E; Schweins, K; Goebel, J; Heusch, P; Nassenstein, K; Schlosser, T; Poeppel, T D

    2017-06-01

    Assessment of increased glucose uptake in inflammatory or malignant myocardial disease using PET/MRI relies on uptake suppression in normal myocardium. We evaluated the efficacy of a ≥24 hours high-fat, low-carbohydrate, and protein-permitted diet (HFLCPP) in combination with unfractionated heparin for suppression of "physiologic" myocardial glucose uptake. PET/MRI was successfully performed in 89 patients. HFLCPP was started ≥24 hours prior to PET/MRI. All patients received i.v. injection of unfractionated heparin (50 IU·kg -1 ) 15 minutes prior to FDG administration. Left ventricular FDG uptake was visually evaluated by two readers. Diffuse myocardial uptake exceeding liver uptake, isolated uptake in the lateral wall, or diffuse uptake in the entire circumference of the heart base were defined as failed suppression. Homogeneous myocardial uptake below liver uptake with/without focal uptake was defined as successful suppression. Success rate was 84%. Suppression was unsuccessful in 14 patients. No significant influence of gender (P = .40) or age (P = .21) was found. However, insufficient suppression was more common in patients younger than 45 years (20% vs 7%). PET/MR imaging completion rate was >97%. A HFLCPP diet in combination with unfractionated heparin was successfully implemented for cardiac PET/MRI and resulted in a sufficient suppression of myocardial FDG uptake in 84% of patients.

  18. Developing a Diagnostic Brain Imaging Protocol for Recent Onset Psychosis which Embodies Principles of Predictive Coding and Free Energy

    Directory of Open Access Journals (Sweden)

    Michael Breakspear

    2011-05-01

    Full Text Available Although schizophrenia is usually conceptualized of as a disorder of well formed hallucinations and delusions, its onset is more typically characterized by heightened arousal, a vague but pervasive feeling of unease and poorly formed misperceptions. This unstable constellation of symptoms challenges clinical diagnosis at a time when properly guided interventions are most likely to have the greatest long-term benefits. It is possible to frame this clinical picture as a disturbance in the capacity of the cortex to optimally form predictive models of the environment, to appropriately sample visual scenes in order to estimate the likelihood of such models and to hence minimize surprise in a dynamic social landscape. This approach suggests that manipulating the relationship between visual search strategies and natural scene statistics might be a sensitive means of quantifying core neurobiological deficits early in the course of emerging psychotic disorders. We are developing a diagnostic tool for the prodromal phase of these disorders which involves experimentally disturbing the relationship between visual saccades and the stream of natural images in well directed films. I will outline the conceptual and computational bases and early experimental results thus far obtained, including a canonical example of paranoia and theory of mind in a spaghetti western.

  19. Optimization on the dose versus noise in the image on protocols for computed tomography of pediatric head; Otimizacao da relacao dose versus ruido na imagem em protocolos de tomografia computadorizada de cranio pediatrico

    Energy Technology Data Exchange (ETDEWEB)

    Saint' Yves, Thalis L.A.; Travassos, Paulo Cesar B.; Goncalves, Elicardo A.S.; Mecca A, Fernando; Silveira, Thiago B. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil)], e-mail: fmecca@inca.gov.br, e-mail: thalis09@yahoo.com.br

    2010-03-15

    This article aims to establish protocols optimized for computed tomography of pediatric skull, to the Picker Q2000 tomography of the Instituto Nacional de Cancer, through the analysis of dose x noise on the image with the variation of values of mAs and kVp. We used a water phantom to measure the noise, a pencil type ionization chamber to measure the dose in the air and the Alderson Randon phantom for check the quality of the image. We found values of mAs and kVp that reduce the skin dose of the original protocol used in 35.9%, maintaining the same image quality at a safe diagnosis. (author)

  20. Formal consensus to identify clinically important changes in management resulting from the use of cardiovascular magnetic resonance (CMR) in patients who activate the primary percutaneous coronary intervention (PPCI) pathway.

    Science.gov (United States)

    Pufulete, Maria; Brierley, Rachel C; Bucciarelli-Ducci, Chiara; Greenwood, John P; Dorman, Stephen; Anderson, Richard A; Harris, Jessica; McAlindon, Elisa; Rogers, Chris A; Reeves, Barnaby C

    2017-06-22

    To define important changes in management arising from the use of cardiovascular magnetic resonance (CMR) in patients who activate the primary percutaneous coronary intervention (PPCI) pathway. Formal consensus study using literature review and cardiologist expert opinion to formulate consensus statements and setting up a consensus panel to review the statements (by completing a web-based survey, attending a face-to-face meeting to discuss survey results and modify the survey to reflect group discussion and completing the modified survey to determine which statements were in consensus). Formulation of consensus statements: four cardiologists (two CMR and two interventional) and six non-clinical researchers. Formal consensus: seven cardiologists (two CMR and three interventional, one echocardiography and one heart failure). Forty-nine additional cardiologists completed the modified survey. Thirty-seven draft statements describing changes in management following CMR were generated; these were condensed into 12 statements and reviewed through the formal consensus process. Three of 12 statements were classified in consensus in the first survey; these related to the role of CMR in identifying the cause of out-of-hospital cardiac arrest, providing a definitive diagnosis in patients found to have unobstructed arteries on angiography and identifying patients with left ventricular thrombus. Two additional statements were in consensus in the modified survey, relating to the ability of CMR to identify patients who have a poor prognosis after PPCI and assess ischaemia and viability in patients with multivessel disease. There was consensus that CMR leads to clinically important changes in management in five subgroups of patients who activate the PPCI pathway. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  1. Coronary artery anomalies. Diagnosis and classification based on cardiac CT and MRI (CMR) - from ALCAPA to anomalies of termination; Koronararterienanomalien. Diagnostik und Klassifikation auf Basis der CT und MRT des Herzens - von ALCAPA bis Terminationsanomalie

    Energy Technology Data Exchange (ETDEWEB)

    Heermann, Philipp; Heindel, Walter; Schuelke, Christoph [University Hospital Muenster (UKM) (Germany). Dept. of Clinical Radiology

    2017-01-15

    Coronary artery anomalies encompass a clinically and anatomically variable spectrum including physiological variants and pathophysiologically relevant anomalies. The majority of the variants has no hemodynamic relevance and is often detected accidentally. The recognition of the rare and relevant anomalies that cause either relevant shunt volumes leading to myocardial ischemia or ventricular tachyarrhythmias with the risk of sudden cardiac death is of major importance. This review is based on a literature search in PubMed conducted using the key words ''coronary artery'' and/or ''anomaly'' and/or ''anomalous origin'' and/or ''myocardial bridging'' and/or ''coronary artery fistula'' and/or ''Bland-White-Garland'' and/or ''ALCAPA''. Coronary artery anomalies can be anatomically subdivided into anomalies of origin, course and termination. The method of choice for anatomical imaging is ECG-triggered or gated multislice CT (MSCT) that provides high spatial resolution and the capability of multiplanar reconstructions. It facilitates the delineation of the precise course of all three coronary arteries and thus allows for correct classification in the anatomical classification system of coronary artery anomalies. The strengths of cardiac magnetic resonance imaging (CMR) are the evaluation of cardiac morphology, myocardial tissue properties and myocardial function. Basic methods are the analysis of myocardial contraction and perfusion with and without pharmacologic stress. Furthermore, potential shunt volumes could be quantified by phase contrast imaging or volumetry.

  2. Criticality Safety Evaluation for Small Sample Preparation and Non-Destructive Assay (NDA) Operations in Wing 7 Basement of the CMR Facility

    Energy Technology Data Exchange (ETDEWEB)

    Kunkle, Paige Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zhang, Ning [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-02

    Nuclear Criticality Safety (NCS) has reviewed the fissionable material small sample preparation and NDA operations in Wing 7 Basement of the CMR Facility. This is a Level-1 evaluation conducted in accordance with NCS-AP-004 [Reference 1], formerly NCS-GUIDE-01, and the guidance set forth on use of the Standard Criticality Safety Requirements (SCSRs) [Reference 2]. As stated in Reference 2, the criticality safety evaluation consists of both the SCSR CSED and the SCSR Application CSED. The SCSR CSED is a Level-3 CSED [Reference 3]. This Level-1 CSED is the SCSR Application CSED. This SCSR Application (Level-1) evaluation does not derive controls, it simply applies controls derived from the SCSR CSED (Level-3) for the application of operations conducted here. The controls derived in the SCSR CSED (Level-3) were evaluated via the process described in Section 6.6.5 of SD-130 (also reproduced in Section 4.3.5 of NCS-AP-004 [Reference 1]) and were determined to not meet the requirements for consideration of elevation into the safety basis documentation for CMR. According to the guidance set forth on use of the SCSRs [Reference 2], the SCSR CSED (Level-3) is also applicable to the CMR Facility because the process and the normal and credible abnormal conditions in question are bounded by those that are described in the SCSR CSED. The controls derived in the SCSR CSED include allowances for solid materials and solution operations. Based on the operations conducted at this location, there are less-than-accountable (LTA) amounts of 233U. Based on the evaluation documented herein, the normal and credible abnormal conditions that might arise during the execution of this process will remain subcritical with the following recommended controls.

  3. A general protocol of ultra-high resolution MR angiography to image the cerebro-vasculature in 6 different rats strains at high field.

    Science.gov (United States)

    Pastor, Géraldine; Jiménez-González, María; Plaza-García, Sandra; Beraza, Marta; Padro, Daniel; Ramos-Cabrer, Pedro; Reese, Torsten

    2017-09-01

    Differences in the cerebro-vasculature among strains as well as individual animals might explain variability in animal models and thus, a non-invasive method tailored to image cerebral vessel of interest with high signal to noise ratio is required. Experimentally, we describe a new general protocol of three-dimensional time-of-flight magnetic resonance angiography to visualize non-invasively the cerebral vasculature in 6 different rat strains. Flow compensated angiograms of Sprague Dawley, Wistar Kyoto, Lister Hooded, Long Evans, Fisher 344 and Spontaneous Hypertensive Rat strains were obtained without the use of contrast agents. At 11.7T using a repetition time of 60ms, an isotropic resolution of up to 62μm was achieved; total imaging time was 98min for a 3D data set. The visualization of the cerebral arteries was improved by removing extra-cranial vessels prior to the calculation of maximum intensity projection to obtain the angiograms. Ultimately, we demonstrate that the newly implemented method is also suitable to obtain angiograms following middle cerebral artery occlusion, despite the presence of intense vasogenic edema 24h after reperfusion. The careful selection of the excitation profile and repetition time at a higher static magnetic field allowed an increase in spatial resolution to reliably detect of the hypothalamic artery, the anterior choroidal artery as well as arterial branches of the peri-amygdoidal complex and the optical nerve in six different rat strains. MR angiography without contrast agent can be utilized to study cerebro-vascular abnormalities in various animal models. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  4. An evaluation of the variability of tumor-shape definition derived by experienced observers from CT images of supraglottic carcinomas (ACRIN protocol 6658)

    International Nuclear Information System (INIS)

    Cooper, Jay S.; Mukherji, Suresh K.; Toledano, Alicia Y.; Beldon, Clifford; Schmalfuss, Ilona M.; Amdur, Robert; Sailer, Scott; Loevner, Laurie A.; Kousouboris, Phil; Ang, K. Kian; Cormack, Jean; Sicks, JoRean M.S.

    2007-01-01

    Purpose: Accurate target definition is considered essential for sophisticated, image-guided radiation therapy; however, relatively little information has been reported that measures our ability to identify the precise shape of targets accurately. We decided to assess the manner in which eight 'experts' interpreted the size and shape of tumors based on 'real-life' contrast-enhanced computed tomographic (CT) scans. Methods and Materials: Four neuroradiologists and four radiation oncologists (the authors) with considerable experience and presumed expertise in treating head-and-neck tumors independently contoured, slice-by-slice, his/her interpretation of the precise gross tumor volume (GTV) on each of 20 sets of CT scans taken from 20 patients who previously were enrolled in Radiation Therapy Oncology Group protocol 91-11. Results: The average proportion of overlap (i.e., the degree of agreement) was 0.532 (95% confidence interval 0.457 to 0.606). There was a slight tendency for the proportion of overlap to increase with increasing average GTV. Conclusions: Our work suggests that estimation of tumor shape currently is imprecise, even for experienced physicians. In consequence, there appears to be a practical limit to the current trend of smaller fields and tighter margins

  5. Cardiac remodeling following percutaneous mitral valve repair - initial results assessed by cardiovascular magnetic resonance imaging

    DEFF Research Database (Denmark)

    Radunski, U K; Franzen, O; Barmeyer, A

    2014-01-01

    PURPOSE: Percutaneous mitral valve repair with the MitraClip device (Abbott Vascular, Redwood City, California, USA) is a novel therapeutic option in patients with mitral regurgitation. This study evaluated the feasibility of cardiac volume measurements by cardiovascular magnetic resonance imaging...... (CMR) to assess reverse myocardial remodeling in patients after MitraClip implantation. MATERIALS AND METHODS: 12 patients underwent CMR at baseline (BL) before and at 6 months follow-up (FU) after MitraClip implantation. Cine-CMR was performed in short- and long-axes for the assessment of left...... end-systolic (48 [42 - 80] vs. 51 [40 - 81] ml/m(2); p = 0.48), and LA (87 [55 - 124] vs. 92 [48 - 137] ml/m(2); p = 0.20) volume indices between BL and FU. CONCLUSION: CMR enables the assessment of cardiac volumes in patients after MitraClip implantation. Our CMR findings indicate that percutaneous...

  6. Research cardiac magnetic resonance imaging in end stage renal disease - incidence, significance and implications of unexpected incidental findings

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, Elaine; Weir-McCall, Jonathan R.; Houston, J.G.; Struthers, Allan D. [Ninewells Hospital, Division of Cardiovascular and Diabetes Medicine, Dundee (United Kingdom); Patel, Rajan K.; Jardine, Alan G.; Mark, Patrick B. [Institute of Cardiovascular and Medical Sciences, Glasgow (United Kingdom); Roditi, Giles [NHS Greater Glasgow and Clyde, Department of Radiology, Glasgow Royal Infirmary, Glasgow (United Kingdom)

    2017-01-15

    Left ventricular mass (LVM) at cardiac magnetic resonance imaging (CMR) is a frequent end point in clinical trials in nephrology. Trial participants with end stage renal disease (ESRD) may have a greater frequency of incidental findings (IF). We retrospectively investigated prevalence of IF in previous research CMR and reviewed their subsequent impact on participants. Between 2002 and 2006, 161 ESRD patients underwent CMR in a transplant assessment study. Images were used to assess LV mass and function. In the current study a radiologist reviewed the scans for IF. Review of patient records determined the subsequent clinical significance of IF. There were 150 IF in 95 study participants. Eighty-four (56 %) were new diagnoses. One hundred and two were non-cardiac. Fifteen were suspicious of malignancy. There was a clinically significant IF for 14.9 % of the participants. In six cases earlier identification of an IF may have improved quality of life or survival. Without radiology support clinically important IF may be missed on CMR. Patients undergoing CMR in trials should be counselled about the frequency and implications of IF. Patients with ESRD have a higher prevalence of IF than reported in other populations. Nephrology studies require mechanisms for radiologist reporting and strategies for dealing with IF. (orig.)

  7. Protocol-based image-guided salvage brachytherapy. Early results in patients with local failure of prostate cancer after radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lahmer, G.; Lotter, M.; Kreppner, S.; Fietkau, R.; Strnad, V. [University Hospital Erlangen (Germany). Dept. of Radiation Oncology

    2013-08-15

    Purpose: To assess the overall clinical outcome of protocol-based image-guided salvage pulsed-dose-rate brachytherapy for locally recurrent prostate cancer after radiotherapy failure particularly regarding feasibility and side effects. Patients and methods: Eighteen consecutive patients with locally recurrent prostate cancer (median age, 69 years) were treated during 2005-2011 with interstitial PDR brachytherapy (PDR-BT) as salvage brachytherapy after radiotherapy failure. The treatment schedule was PDR-BT two times with 30 Gy (pulse dose 0.6 Gy/h, 24 h per day) corresponding to a total dose of 60 Gy. Dose volume adaptation was performed with the aim of optimal coverage of the whole prostate (V{sub 100} > 95 %) simultaneously respecting the protocol-based dose volume constraints for the urethra (D{sub 0.1} {sub cc} < 130 %) and the rectum (D{sub 2} {sub cc} < 50-60 %) taking into account the previous radiation therapy. Local relapse after radiotherapy (external beam irradiation, brachytherapy with J-125 seeds or combination) was confirmed mostly via choline-PET and increased PSA levels. The primary endpoint was treatment-related late toxicities - particularly proctitis, anal incontinence, cystitis, urinary incontinence, urinary frequency/urgency, and urinary retention according to the Common Toxicity Criteria. The secondary endpoint was PSA-recurrence-free survival. Results: We registered urinary toxicities only. Grade 2 and grade 3 toxicities were observed in up to 11.1 % (2/18) and 16.7 % (3/18) of patients, respectively. The most frequent late-event grade 3 toxicity was urinary retention in 17 % (3/18) of patients. No late gastrointestinal side effects occurred. The biochemical PSA-recurrence-free survival probability at 3 years was 57.1 %. The overall survival at 3 years was 88.9 %; 22 % (4/18) of patients developed metastases. The median follow-up time for all patients after salvage BT was 21 months (range, 8-77 months). Conclusion: Salvage PDR

  8. Cryptographic Protocols:

    DEFF Research Database (Denmark)

    Geisler, Martin Joakim Bittel

    cryptography was thus concerned with message confidentiality and integrity. Modern cryptography cover a much wider range of subjects including the area of secure multiparty computation, which will be the main topic of this dissertation. Our first contribution is a new protocol for secure comparison, presented...... implemented the comparison protocol in Java and benchmarks show that is it highly competitive and practical. The biggest contribution of this dissertation is a general framework for secure multiparty computation. Instead of making new ad hoc implementations for each protocol, we want a single and extensible...... in Chapter 2. Comparisons play a key role in many systems such as online auctions and benchmarks — it is not unreasonable to say that when parties come together for a multiparty computation, it is because they want to make decisions that depend on private information. Decisions depend on comparisons. We have...

  9. Computed tomography of the cervical spine: comparison of image quality between a standard-dose and a low-dose protocol using filtered back-projection and iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Becce, Fabio [University of Lausanne, Department of Diagnostic and Interventional Radiology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Universite Catholique Louvain, Department of Radiology, Cliniques Universitaires Saint-Luc, Brussels (Belgium); Ben Salah, Yosr; Berg, Bruno C. vande; Lecouvet, Frederic E.; Omoumi, Patrick [Universite Catholique Louvain, Department of Radiology, Cliniques Universitaires Saint-Luc, Brussels (Belgium); Verdun, Francis R. [University of Lausanne, Institute of Radiation Physics, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Meuli, Reto [University of Lausanne, Department of Diagnostic and Interventional Radiology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland)

    2013-07-15

    To compare image quality of a standard-dose (SD) and a low-dose (LD) cervical spine CT protocol using filtered back-projection (FBP) and iterative reconstruction (IR). Forty patients investigated by cervical spine CT were prospectively randomised into two groups: SD (120 kVp, 275 mAs) and LD (120 kVp, 150 mAs), both applying automatic tube current modulation. Data were reconstructed using both FBP and sinogram-affirmed IR. Image noise, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were measured. Two radiologists independently and blindly assessed the following anatomical structures at C3-C4 and C6-C7 levels, using a four-point scale: intervertebral disc, content of neural foramina and dural sac, ligaments, soft tissues and vertebrae. They subsequently rated overall image quality using a ten-point scale. For both protocols and at each disc level, IR significantly decreased image noise and increased SNR and CNR, compared with FBP. SNR and CNR were statistically equivalent in LD-IR and SD-FBP protocols. Regardless of the dose and disc level, the qualitative scores with IR compared with FBP, and with LD-IR compared with SD-FBP, were significantly higher or not statistically different for intervertebral discs, neural foramina and ligaments, while significantly lower or not statistically different for soft tissues and vertebrae. The overall image quality scores were significantly higher with IR compared with FBP, and with LD-IR compared with SD-FBP. LD-IR cervical spine CT provides better image quality for intervertebral discs, neural foramina and ligaments, and worse image quality for soft tissues and vertebrae, compared with SD-FBP, while reducing radiation dose by approximately 40 %. (orig.)

  10. Computed tomography of the cervical spine: comparison of image quality between a standard-dose and a low-dose protocol using filtered back-projection and iterative reconstruction

    International Nuclear Information System (INIS)

    Becce, Fabio; Ben Salah, Yosr; Berg, Bruno C. vande; Lecouvet, Frederic E.; Omoumi, Patrick; Verdun, Francis R.; Meuli, Reto

    2013-01-01

    To compare image quality of a standard-dose (SD) and a low-dose (LD) cervical spine CT protocol using filtered back-projection (FBP) and iterative reconstruction (IR). Forty patients investigated by cervical spine CT were prospectively randomised into two groups: SD (120 kVp, 275 mAs) and LD (120 kVp, 150 mAs), both applying automatic tube current modulation. Data were reconstructed using both FBP and sinogram-affirmed IR. Image noise, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were measured. Two radiologists independently and blindly assessed the following anatomical structures at C3-C4 and C6-C7 levels, using a four-point scale: intervertebral disc, content of neural foramina and dural sac, ligaments, soft tissues and vertebrae. They subsequently rated overall image quality using a ten-point scale. For both protocols and at each disc level, IR significantly decreased image noise and increased SNR and CNR, compared with FBP. SNR and CNR were statistically equivalent in LD-IR and SD-FBP protocols. Regardless of the dose and disc level, the qualitative scores with IR compared with FBP, and with LD-IR compared with SD-FBP, were significantly higher or not statistically different for intervertebral discs, neural foramina and ligaments, while significantly lower or not statistically different for soft tissues and vertebrae. The overall image quality scores were significantly higher with IR compared with FBP, and with LD-IR compared with SD-FBP. LD-IR cervical spine CT provides better image quality for intervertebral discs, neural foramina and ligaments, and worse image quality for soft tissues and vertebrae, compared with SD-FBP, while reducing radiation dose by approximately 40 %. (orig.)

  11. Usefulness of cardiovascular magnetic resonance imaging to predict the need for intervention in patients with coarctation of the aorta.

    Science.gov (United States)

    Muzzarelli, Stefano; Meadows, Alison Knauth; Ordovas, Karen Gomes; Higgins, Charles Bernard; Meadows, Jeffery Joshua

    2012-03-15

    Cardiovascular magnetic resonance (CMR) imaging can predict hemodynamically significant coarctation of the aorta (CoA) with a high degree of discrimination. However, the ability of CMR to predict important clinical outcomes in this patient population is unknown. Therefore, we sought to define the ability of CMR to predict the need for surgical or transcatheter intervention in patients with CoA. We retrospectively reviewed the data from 133 consecutive patients who had undergone CMR for the evaluation of known or suspected CoA. The characteristics of the CMR-derived variables predicting the need for surgical or transcatheter intervention for CoA within 1 year were determined through logistic regression analysis. Therapeutic aortic intervention was performed in 41 (31%) of the 133 patients during the study period. The indexed minimum aortic cross-sectional area was the strongest predictor of subsequent intervention (area under the receiver operating characteristic curve 0.975) followed by heart rate-corrected deceleration time in the descending aorta (area under the receiver operating characteristic curve 0.951), and the percentage of flow increase (area under the receiver operating characteristic curve 0.867). The combination of the indexed minimum aortic cross-sectional area and rate-corrected deceleration time in the descending aorta provided the best predictive model (area under the receiver operating characteristic curve 0.986). In conclusion, CMR findings can predict the need for subsequent intervention in CoA. These findings reinforce the "gate-keeper role" of CMR to cardiac catheterization by providing valuable diagnostic and powerful prognostic information and could guide additional treatment of patients with CoA with the final intent of reducing the number of diagnostic catheterizations in such patients. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Immunochemical protocols

    National Research Council Canada - National Science Library

    Pound, John D

    1998-01-01

    ... easy and important refinements often are not published. This much anticipated 2nd edition of Immunochemzcal Protocols therefore aims to provide a user-friendly up-to-date handbook of reliable techniques selected to suit the needs of molecular biologists. It covers the full breadth of the relevant established immunochemical methods, from protein blotting and immunoa...

  13. A novel PET imaging protocol identifies seizure-induced regional overactivity of P-glycoprotein at the blood-brain barrier

    Science.gov (United States)

    Bankstahl, Jens P.; Bankstahl, Marion; Kuntner, Claudia; Stanek, Johann; Wanek, Thomas; Meier, Martin; Ding, Xiao-Qi; Müller, Markus; Langer, Oliver; Löscher, Wolfgang

    2013-01-01

    About one third of epilepsy patients are pharmacoresistant. Overexpression of P-glycoprotein and other multidrug transporters at the blood-brain barrier is thought to play an important role in drug-refractory epilepsy. Thus, quantification of regionally different P-glycoprotein activity in the brain in vivo is essential to identify P-glycoprotein overactivity as the relevant mechanism for drug-resistance in an individual patient. Using the radiolabeled P-glycoprotein substrate (R)-[11C]verapamil and different doses of co-administered tariquidar, which is an inhibitor of P-glycoprotein, we evaluated whether small-animal positron emission tomography (PET) can quantify regional changes in transporter function in the rat brain at baseline and 48 h after a pilocarpine-induced status epilepticus. P-glycoprotein expression was additionally quantified by immunohistochemistry. To reveal putative seizure-induced changes in blood-brain barrier integrity, we performed gadolinium-enhanced magnetic resonance scans on a 7.0 Tesla small-animal scanner. Before P-glycoprotein modulation, brain uptake of (R)-[11C]verapamil was low in all regions investigated in control and post-status epilepticus rats. After administration of 3 mg/kg tariquidar, which inhibits P-glycoprotein only partially, we observed increased regional differentiation in brain activity uptake in post-status epilepticus versus control rats, which diminished after maximal P-glycoprotein inhibition. Regional increases in the efflux rate constant k2, but not in distribution volume VT or influx rate constant K1, correlated significantly with increases in P-glycoprotein expression measured by immunohistochemistry. This imaging protocol proves to be suitable to detect seizure-induced regional changes in P-glycoprotein activity and is readily applicable to humans, with the aim to detect relevant mechanisms of pharmacoresistance in epilepsy in vivo. PMID:21677164

  14. Value of Cardiovascular Magnetic Resonance Imaging in Noninvasive Risk Stratification in Tetralogy of Fallot

    NARCIS (Netherlands)

    Bokma, Jouke P.; de Wilde, Koen C.; Vliegen, Hubert W.; van Dijk, Arie P.; van Melle, Joost P.; Meijboom, Folkert J.; Zwinderman, Aeilko H.; Groenink, Maarten; Mulder, Barbara J. M.; Bouma, Berto J.

    IMPORTANCE Adults late after total correction of tetralogy of Fallot (TOF) are at risk for majorcomplications. Cardiovascular magnetic resonance (CMR) imaging is recommended toquantify right ventricular (RV) and left ventricular (LV) function. However, a commonly usedrisk model by Khairy et al

  15. Star Imager

    DEFF Research Database (Denmark)

    Madsen, Peter Buch; Jørgensen, John Leif; Thuesen, Gøsta

    1997-01-01

    The version of the star imager developed for Astrid II is described. All functions and features are described as well as the operations and the software protocol.......The version of the star imager developed for Astrid II is described. All functions and features are described as well as the operations and the software protocol....

  16. Exploratory use of cardiovascular magnetic resonance imaging in liver transplantation: a one-stop shop for preoperative cardiohepatic evaluation.

    Science.gov (United States)

    Reddy, Sahadev T; Thai, Ngoc L; Fakhri, Asghar A; Oliva, Jose; Tom, Kusum B; Dishart, Michael K; Doyle, Mark; Yamrozik, June A; Williams, Ronald B; Grant, Saundra B; Poydence, Jacqueline; Shah, Moneal; Singh, Anil; Nathan, Swami; Biederman, Robert W W

    2013-11-15

    Preoperative cardiovascular risk stratification in orthotopic liver transplantation candidates has proven challenging due to limitations of current noninvasive modalities. Additionally, the preoperative workup is logistically cumbersome and expensive given the need for separate cardiac, vascular, and abdominal imaging. We evaluated the feasibility of a "one-stop shop" in a magnetic resonance suite, performing assessment of cardiac structure, function, and viability, along with simultaneous evaluation of thoracoabdominal vasculature and liver anatomy. In this pilot study, patients underwent steady-state free precession sequences and stress cardiac magnetic resonance (CMR), thoracoabdominal magnetic resonance angiography, and abdominal magnetic resonance imaging (MRI) on a standard MRI scanner. Pharmacologic stress was performed using regadenoson, adenosine, or dobutamine. Viability was assessed using late gadolinium enhancement. Over 2 years, 51 of 77 liver transplant candidates (mean age, 56 years; 35% female; mean Model for End-stage Liver Disease score, 10.8; range, 6-40) underwent MRI. All referred patients completed standard dynamic CMR, 98% completed stress CMR, 82% completed late gadolinium enhancement for viability, 94% completed liver MRI, and 88% completed magnetic resonance angiography. The mean duration of the entire study was 72 min, and 45 patients were able to complete the entire examination. Among all 51 patients, 4 required follow-up coronary angiography (3 for evidence of ischemia on perfusion CMR and 1 for postoperative ischemia), and none had flow-limiting coronary disease. Nine proceeded to orthotopic liver transplantation (mean 74 days to transplantation after MRI). There were six ascertained mortalities in the nontransplant group and one death in the transplanted group. Explant pathology confirmed 100% detection/exclusion of hepatocellular carcinoma. No complications during CMR examination were encountered. In this proof-of-concept study, it

  17. An assessment of the magnitude of intra-fraction movement of head-and-neck IMRT cases and its implication on the action-level of the imaging protocol

    International Nuclear Information System (INIS)

    Pang, Pei Ping Eric; Hendry, Julie; Cheah, Shie Lee; Soong, Yoke Lim; Fong, Kam Weng; Wee, Tien Seng Joseph; Tan, Wee Kiat Terence; Nei, Wen Long; Wang, Fuqiang; Wong, Ru Xin; Ng, Wee Loon; Chen, John

    2014-01-01

    Background and purpose: A planning margin ⩽3 mm is employed in some head-and-neck IMRT cases due to the proximity of critical structures. This study aims to explore the need to redefine the action-level in the head-and-neck imaging protocol in consideration of the intra-fraction movement. Material and methods: This is a local study of 18 patients treated using the same immobilisation system and setup protocol. Post-treatment orthogonal pair of kilovoltage X-ray images was acquired on the first three days of treatment. 106 sets of pre- and post-treatment kV X-ray images acquired over 53 fractions were analysed against the treatment planning DRR for calculation of intra-fraction movement. Results: Individual mean intra-fraction movement in all directions ranged from −1.8 to 1.1 mm. Population mean (median) intra-fraction movement in the x-, y-, and z-planes were −0.1 mm (0 mm), −0.3 mm (−0.3 mm) and −0.2 mm (−0.2 mm) respectively. Intra-fraction movement in all three dimensions, x-, y- and z-planes were considered statistically significant (p < 0.05). 7 out of 53 fractions (13.2%) were highlighted as the combined magnitude of the intra-fraction motion with the uncorrected pre-treatment setup errors had exceeded the boundaries of given margins. Conclusions: 3 mm-AL was not adequate to account for intra-fraction movement when the CTV–PTV margin was ⩽3 mm and should be excluded from the routine imaging protocol and daily image-guided radiotherapy should be employed. Adjusting the action-level to 2 mm would allow a more confident approach in delivery of the prescribed dose in head-and-neck IMRT cases

  18. Comparison of echocardiographic and cardiac magnetic resonance imaging measurements of functional single ventricular volumes, mass, and ejection fraction (from the Pediatric Heart Network Fontan Cross-Sectional Study).

    Science.gov (United States)

    Margossian, Renee; Schwartz, Marcy L; Prakash, Ashwin; Wruck, Lisa; Colan, Steven D; Atz, Andrew M; Bradley, Timothy J; Fogel, Mark A; Hurwitz, Lynne M; Marcus, Edward; Powell, Andrew J; Printz, Beth F; Puchalski, Michael D; Rychik, Jack; Shirali, Girish; Williams, Richard; Yoo, Shi-Joon; Geva, Tal

    2009-08-01

    Assessment of the size and function of a functional single ventricle (FSV) is a key element in the management of patients after the Fontan procedure. Measurement variability of ventricular mass, volume, and ejection fraction (EF) among observers by echocardiography and cardiac magnetic resonance imaging (CMR) and their reproducibility among readers in these patients have not been described. From the 546 patients enrolled in the Pediatric Heart Network Fontan Cross-Sectional Study (mean age 11.9 +/- 3.4 years), 100 echocardiograms and 50 CMR studies were assessed for measurement reproducibility; 124 subjects with paired studies were selected for comparison between modalities. Interobserver agreement for qualitative grading of ventricular function by echocardiography was modest for left ventricular (LV) morphology (kappa = 0.42) and weak for right ventricular (RV) morphology (kappa = 0.12). For quantitative assessment, high intraclass correlation coefficients were found for echocardiographic interobserver agreement (LV 0.87 to 0.92, RV 0.82 to 0.85) of systolic and diastolic volumes, respectively. In contrast, intraclass correlation coefficients for LV and RV mass were moderate (LV 0.78, RV 0.72). The corresponding intraclass correlation coefficients by CMR were high (LV 0.96, RV 0.85). Volumes by echocardiography averaged 70% of CMR values. Interobserver reproducibility for the EF was similar for the 2 modalities. Although the absolute mean difference between modalities for the EF was small (<2%), 95% limits of agreement were wide. In conclusion, agreement between observers of qualitative FSV function by echocardiography is modest. Measurements of FSV volume by 2-dimensional echocardiography underestimate CMR measurements, but their reproducibility is high. Echocardiographic and CMR measurements of FSV EF demonstrate similar interobserver reproducibility, whereas measurements of FSV mass and LV diastolic volume are more reproducible by CMR.

  19. Assessment of acute myocarditis by cardiac magnetic resonance imaging: Comparison of qualitative and quantitative analysis methods.

    Science.gov (United States)

    Imbriaco, Massimo; Nappi, Carmela; Puglia, Marta; De Giorgi, Marco; Dell'Aversana, Serena; Cuocolo, Renato; Ponsiglione, Andrea; De Giorgi, Igino; Polito, Maria Vincenza; Klain, Michele; Piscione, Federico; Pace, Leonardo; Cuocolo, Alberto

    2017-10-26

    To compare cardiac magnetic resonance (CMR) qualitative and quantitative analysis methods for the noninvasive assessment of myocardial inflammation in patients with suspected acute myocarditis (AM). A total of 61 patients with suspected AM underwent coronary angiography and CMR. Qualitative analysis was performed applying Lake-Louise Criteria (LLC), followed by quantitative analysis based on the evaluation of edema ratio (ER) and global relative enhancement (RE). Diagnostic performance was assessed for each method by measuring the area under the curves (AUC) of the receiver operating characteristic analyses. The final diagnosis of AM was based on symptoms and signs suggestive of cardiac disease, evidence of myocardial injury as defined by electrocardiogram changes, elevated troponin I, exclusion of coronary artery disease by coronary angiography, and clinical and echocardiographic follow-up at 3 months after admission to the chest pain unit. In all patients, coronary angiography did not show significant coronary artery stenosis. Troponin I levels and creatine kinase were higher in patients with AM compared to those without (both P quantitative (ER 0.89 and global RE 0.80) analyses were also similar. Qualitative and quantitative CMR analysis methods show similar diagnostic accuracy for the diagnosis of AM. These findings suggest that a simplified approach using a shortened CMR protocol including only T2-weighted STIR sequences might be useful to rule out AM in patients with acute coronary syndrome and normal coronary angiography.

  20. Digital breast tomosynthesis plus synthesised images versus standard full-field digital mammography in population-based screening (TOSYMA): protocol of a randomised controlled trial.

    Science.gov (United States)

    Weigel, Stefanie; Gerss, Joachim; Hense, Hans-Werner; Krischke, Miriam; Sommer, Alexander; Czwoydzinski, Jörg; Lenzen, Horst; Kerschke, Laura; Spieker, Karin; Dickmaenken, Stefanie; Baier, Sonja; Urban, Marc; Hecht, Gerold; Heidinger, Oliver; Kieschke, Joachim; Heindel, Walter

    2018-05-14

    Development of digital breast tomosynthesis (DBT) provides a technology that generates three-dimensional data sets, thus reducing the pitfalls of overlapping breast tissue. Observational studies suggest that the combination of two-dimensional (2D) digital mammography and DBT increases diagnostic accuracy. However, because of duplicate exposure, this comes at the cost of an augmented radiation dose. This undesired adverse impact can be avoided by using synthesised 2D images reconstructed from the DBT data (s2D).We designed a diagnostic superiority trial on a high level of evidence with the aim of providing a comparison of screening efficacy parameters resulting from DBT+s2D versus the current screening standard 2D full-field digital mammography (FFDM) in a multicentre and multivendor setting on the basis of the quality-controlled, population-based, biennial mammography screening programme in Germany. 80 000 women in the eligible age 50-69 years attending the routine mammography screening programme and willing to participate in the TOSYMA trial will be assigned by 1:1 randomisation to either the intervention arm (DBT+s2D) or the control arm (FFDM) during a 12-month recruitment period in screening units of North Rhine-Westphalia and Lower Saxony. State cancer registries will provide the follow-up of interval cancers.Primary endpoints are the detection rate of invasive breast cancers at screening examination and the cumulative incidence of interval cancers in the 2 years after a negative examination. Secondary endpoints are the detection rate of ductal carcinoma in situ and of tumour size T1, the recall rate for assessment, the positive predictive value of recall and the cumulative 12-month incidence of interval cancers. An adaptive statistical design with one interim analysis provides the option to modify the design. This protocol has been approved by the local medical ethical committee (2016-132-f-S). Results will be submitted to international peer

  1. Dynamic properties of the Sulfolobus CRISPR/Cas and CRISPR/Cmr systems when challenged with vector-borne viral and plasmid genes and protospacers

    DEFF Research Database (Denmark)

    Guðbergsdóttir, Sóley Ruth; Deng, Ling; Chen, Zhengjun

    2011-01-01

    The adaptive immune CRISPR/Cas and CRISPR/Cmr systems of the crenarchaeal thermoacidophile Sulfolobus were challenged by a variety of viral and plasmid genes, and protospacers preceded by different dinucleotide motifs. The genes and protospacers were constructed to carry sequences matching...... individual spacers of CRISPR loci, and a range of mismatches were introduced. Constructs were cloned into vectors carrying pyrE/pyrF genes and transformed into uracil auxotrophic hosts derived from Sulfolobus solfataricus P2 or Sulfolobus islandicus REY15A. Most constructs, including those carrying different...... protospacer mismatches, yielded few viable transformants. These were shown to carry either partial deletions of CRISPR loci, covering a broad spectrum of sizes and including the matching spacer, or deletions of whole CRISPR/Cas modules. The deletions occurred independently of whether genes or protospacers...

  2. Study protocol

    DEFF Research Database (Denmark)

    Smith, Benjamin E; Hendrick, Paul; Bateman, Marcus

    2017-01-01

    avoidance behaviours, catastrophising, self-efficacy, sport and leisure activity participation, and general quality of life. Follow-up will be 3 and 6 months. The analysis will focus on descriptive statistics and confidence intervals. The qualitative components will follow a thematic analysis approach....... DISCUSSION: This study will evaluate the feasibility of running a definitive large-scale trial on patients with patellofemoral pain, within the NHS in the UK. We will identify strengths and weaknesses of the proposed protocol and the utility and characteristics of the outcome measures. The results from...... this study will inform the design of a multicentre trial. TRIAL REGISTRATION: ISRCTN35272486....

  3. Feasibility of quantification of the distribution of blood flow in the normal human fetal circulation using CMR: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Seed Mike

    2012-11-01

    Full Text Available Abstract Background We present the first phase contrast (PC cardiovascular magnetic resonance (CMR measurements of the distribution of blood flow in twelve late gestation human fetuses. These were obtained using a retrospective gating technique known as metric optimised gating (MOG. Methods A validation experiment was performed in five adult volunteers where conventional cardiac gating was compared with MOG. Linear regression and Bland Altman plots were used to compare MOG with the gold standard of conventional gating. Measurements using MOG were then made in twelve normal fetuses at a median gestational age of 37 weeks (range 30–39 weeks. Flow was measured in the major fetal vessels and indexed to the fetal weight. Results There was good correlation between the conventional gated and MOG measurements in the adult validation experiment (R=0.96. Mean flows in ml/min/kg with standard deviations in the major fetal vessels were as follows: combined ventricular output (CVO 540±101, main pulmonary artery (MPA 327±68, ascending aorta (AAo 198±38, superior vena cava (SVC 147±46, ductus arteriosus (DA 220±39,pulmonary blood flow (PBF 106±59,descending aorta (DAo 273±85, umbilical vein (UV 160±62, foramen ovale (FO107±54. Results expressed as mean percentages of the CVO with standard deviations were as follows: MPA 60±4, AAo37±4, SVC 28±7, DA 41±8, PBF 19±10, DAo50±12, UV 30±9, FO 21±12. Conclusion This study demonstrates how PC CMR with MOG is a feasible technique for measuring the distribution of the normal human fetal circulation in late pregnancy. Our preliminary results are in keeping with findings from previous experimental work in fetal lambs.

  4. Feasibility of quantification of the distribution of blood flow in the normal human fetal circulation using CMR: a cross-sectional study.

    Science.gov (United States)

    Seed, Mike; van Amerom, Joshua F P; Yoo, Shi-Joon; Al Nafisi, Bahiyah; Grosse-Wortmann, Lars; Jaeggi, Edgar; Jansz, Michael S; Macgowan, Christopher K

    2012-11-26

    We present the first phase contrast (PC) cardiovascular magnetic resonance (CMR) measurements of the distribution of blood flow in twelve late gestation human fetuses. These were obtained using a retrospective gating technique known as metric optimised gating (MOG). A validation experiment was performed in five adult volunteers where conventional cardiac gating was compared with MOG. Linear regression and Bland Altman plots were used to compare MOG with the gold standard of conventional gating. Measurements using MOG were then made in twelve normal fetuses at a median gestational age of 37 weeks (range 30-39 weeks). Flow was measured in the major fetal vessels and indexed to the fetal weight. There was good correlation between the conventional gated and MOG measurements in the adult validation experiment (R=0.96). Mean flows in ml/min/kg with standard deviations in the major fetal vessels were as follows: combined ventricular output (CVO) 540 ± 101, main pulmonary artery (MPA) 327 ± 68, ascending aorta (AAo) 198 ± 38, superior vena cava (SVC) 147 ± 46, ductus arteriosus (DA) 220 ± 39,pulmonary blood flow (PBF) 106 ± 59,descending aorta (DAo) 273 ± 85, umbilical vein (UV) 160 ± 62, foramen ovale (FO)107 ± 54. Results expressed as mean percentages of the CVO with standard deviations were as follows: MPA 60 ± 4, AAo37 ± 4, SVC 28 ± 7, DA 41 ± 8, PBF 19 ± 10, DAo50 ± 12, UV 30 ± 9, FO 21 ± 12. This study demonstrates how PC CMR with MOG is a feasible technique for measuring the distribution of the normal human fetal circulation in late pregnancy. Our preliminary results are in keeping with findings from previous experimental work in fetal lambs.

  5. Diagnostic accuracy of cardiovascular magnetic resonance imaging for assessment of right ventricular morphology and function in pulmonary artery hypertension

    Directory of Open Access Journals (Sweden)

    Eman Ramzy Ali

    2017-07-01

    Conclusions: CMR imaging is likely to increase in importance as the optimal reference method for assessment of early structural (morphological and functional parameters of the right ventricle for evaluation of patients with suspected PH valuable for assessment of treatment response, follow up and prognosis.

  6. Cardiovascular Magnetic Resonance T2-STIR Imaging is Unable to Discriminate Between Intramyocardial Haemorrhage and Microvascular Obstruction

    DEFF Research Database (Denmark)

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

    2015-01-01

    Recent studies have used cardiovascular magnetic resonance (CMR) and T2-weighted short tau inversion recovery (T2-STIR) imaging to detect intramyocardial haemorrhage (IMH) as a measure of ischemic/reperfusion injury. We investigated the ability of T2-STIR to differentiate between microvascular...

  7. Beyond protocols

    DEFF Research Database (Denmark)

    Vanderhoeven, Sonia; Branquart, Etienne; Casaer, Jim

    2017-01-01

    Risk assessment tools for listing invasive alien species need to incorporate all available evidence and expertise. Beyond the wealth of protocols developed to date, we argue that the current way of performing risk analysis has several shortcomings. In particular, lack of data on ecological impact...... information on risk and the exploration of improved methods for decision making on biodiversity management. This is crucial for efficient conservation resource allocation and uptake by stakeholders and the public......., transparency and repeatability of assessments as well as the incorporation of uncertainty should all be explicitly considered. We recommend improved quality control of risk assessments through formalized peer review with clear feedback between assessors and reviewers. Alternatively, a consensus building...

  8. Evaluating microvascular obstruction after acute myocardial infarction using cardiac magnetic resonance imaging and 201-thallium and 99m-technetium pyrophosphate scintigraphy

    International Nuclear Information System (INIS)

    Onishi, Takayuki; Kobayashi, Isshi; Onishi, Yuko; Kawashima, Tomoyuki; Muramoto, Hirotaka; Nakamura, Hiroaki; Nagata, Yasutoshi; Umezawa, Shigeo; Niwa, Akihiro

    2010-01-01

    Few studies have compared the ability of cardiac magnetic resonance (CMR) with that of scintigraphy using 201-thallium (201-Tl) and 99m-technetium pyrophosphate (99m-Tc PYP) to evaluate microvascular obstructions (MOs). In the present study the relationship between the scintigraphic and CMR characteristics of MOs after acute myocardial infarction (MI) was examined. The 14 patients (age 69±8 years, 11 males) underwent 201-Tl/99m-Tc PYP single photon emission computed tomography (SPECT) 7±3 days, initial CMR 16±12 days, and follow-up CMR 193±20 days after a reperfused first acute MI. Each image was analyzed using a 17-segment model. Segmental extent of delayed enhancement (DE), wall motion (WM) and degree of 201-Tl uptake were scored in 238 segments. Of 91 MI segments, MO was recognized in 22 (25%) segments on CMR. WM was significantly better in proportion to 201-Tl uptake (P=0.01) in MO segments. All 8 MO segments with WM improvement at follow-up had 99m-Tc PYP uptake, although only 3 (21%) of 14 MO segments that did not show WM improvement at follow-up had 99m-Tc PYP uptake (P=0.001). 99m-Tc PYP and 201-Tl scintigraphy have the potential to predict WM status and improvement of the MO region after reperfused acute MI. (author)

  9. Adaptation of a MR imaging protocol into a real-time clinical biometric ultrasound protocol for persons with spinal cord injury at risk for deep tissue injury: A reliability study.

    Science.gov (United States)

    Swaine, Jillian M; Moe, Andrew; Breidahl, William; Bader, Daniel L; Oomens, Cees W J; Lester, Leanne; O'Loughlin, Edmond; Santamaria, Nick; Stacey, Michael C

    2018-02-01

    High strain in soft tissues that overly bony prominences are considered a risk factor for pressure ulcers (PUs) following spinal cord impairment (SCI) and have been computed using Finite Element methods (FEM). The aim of this study was to translate a MRI protocol into ultrasound (US) and determine between-operator reliability of expert sonographers measuring diameter of the inferior curvature of the ischial tuberosity (IT) and the thickness of the overlying soft tissue layers on able-bodied (AB) and SCI using real-time ultrasound. Part 1: Fourteen AB participants with a mean age of 36.7 ± 12.09 years with 7 males and 7 females had their 3 soft tissue layers in loaded and unloaded sitting measured independently by 2 sonographers: tendon/muscle, skin/fat and total soft tissue and the diameter of the IT in its short and long axis. Part 2: Nineteen participants with SCI were screened, three were excluded due to abnormal skin signs, and eight participants (42%) were excluded for abnormal US signs with normal skin. Eight SCI participants with a mean age of 31.6 ± 13.6 years and all male with 4 paraplegics and 4 tetraplegics were measured by the same sonographers for skin, fat, tendon, muscle and total. Skin/fat and tendon/muscle were computed. AB between-operator reliability was good (ICC = 0.81-0.90) for 3 soft tissues layers in unloaded and loaded sitting and poor for both IT short and long axis (ICC = -0.028 and -0.01). SCI between-operator reliability was good in unloaded and loaded for total, muscle, fat, skin/fat, tendon/muscle (ICC = 0.75-0.97) and poor for tendon (ICC = 0.26 unloaded and ICC = -0.71 loaded) and skin (ICC = 0.37 unloaded and ICC = 0.10). A MRI protocol was successfully adapted for a reliable 3 soft tissue layer model and could be used in a 2-D FEM model designed to estimate soft tissue strain as a novel risk factor for the development of a PU. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Left ventricular hypertrophy: The relationship between the electrocardiogram and cardiovascular magnetic resonance imaging.

    Science.gov (United States)

    Bacharova, Ljuba; Ugander, Martin

    2014-11-01

    Conventional assessment of left ventricular hypertrophy (LVH) using the electrocardiogram (ECG), for example, by the Sokolow-Lyon, Romhilt-Estes or Cornell criteria, have relied on assessing changes in the amplitude and/or duration of the QRS complex of the ECG to quantify LV mass. ECG measures of LV mass have typically been validated by imaging with echocardiography or cardiovascular magnetic resonance imaging (CMR). However, LVH can be the result of diverse etiologies, and LVH is also characterized by pathological changes in myocardial tissue characteristics on the genetic, molecular, cellular, and tissue level beyond a pure increase in the number of otherwise normal cardiomyocytes. For example, slowed conduction velocity through the myocardium, which can be due to diffuse myocardial fibrosis, has been shown to be an important determinant of conventional ECG LVH criteria regardless of LV mass. Myocardial tissue characterization by CMR has emerged to not only quantify LV mass, but also detect and quantify the extent and severity of focal or diffuse myocardial fibrosis, edema, inflammation, myocarditis, fatty replacement, myocardial disarray, and myocardial deposition of amyloid proteins (amyloidosis), glycolipids (Fabry disease), or iron (siderosis). This can be undertaken using CMR techniques including late gadolinium enhancement (LGE), T1 mapping, T2 mapping, T2* mapping, extracellular volume fraction (ECV) mapping, fat/water-weighted imaging, and diffusion tensor CMR. This review presents an overview of current and emerging concepts regarding the diagnostic possibilities of both ECG and CMR for LVH in an attempt to narrow gaps in our knowledge regarding the ECG diagnosis of LVH. © 2014 Wiley Periodicals, Inc.

  11. The utility of MR imaging of the shoulder joint: comparison of the MR imaging between conventional MR imaging and arthrographic MR imaging

    International Nuclear Information System (INIS)

    Choi, Dong Sik; Ryu, Kyung Nam; Kim, Ihn Sub; Rhee, Yong Girl

    1998-01-01

    To evaluate the diagnostic value of MRI of the shoulder. Between January and June 1997, shoulder MRI and arthroscopy were performed in a total of 48 patients with shoulder pain (n=3D30) or shoulder instability (n=3D18). Forty-five were males and three were females; their ages ranged from 16 to 67 (mean 32.5) years. The period between shoulder MRI and arthroscopy was between one and 390 (mean, 42.2) days. Twenty-six patents underwent MR arthrography (AMR), and 22 conventional MRI(CMR). Each image was analyzed for rotator cuff injury, glenoid labral injury, SLAP lesion, and biceps tendon injury. On arthroscopy, one disease was found in 34 patients, two were found in six, three diseases were found in seven, and one patient had four diseases. Arthroscopic diagnosis was as follows:rotator cuff injury, 29;SLAP lesion, 12;glenoid labral injury, 10;biceps tendon injury, 4;subacromial bursitis, 2;chronic synovitis, 1;adhesive capsulitis, 1;superior glenohumeral ligament injury, 1;normal, 1. For rotator cuff injury, the sensitivity of MRI was 65.5% and specificity was 93.0% (AMR:66.7%, 95.8%, CMR:65.2%, 86.4%). For SLAP lesion, sensitivity was 58.3% and specificity was 97.2% (AMR:66.7%, 100%, CMR:50%, 93.8%);for glenoid labral injury, sensitivity was 80.0% and specificity was 89.5% (AMR:85.7%, 84.2%, CMR:66.7%, 94.7%), and for biceps tendon injury, the false negative rate was 100%. In cases involving glenoid labral injury, the diagnostic accuracy of shoulder MRI was relatively high;in rotator cuff injury and SLAP lesion, however, diagnosis was limited, and in biceps tendon injury was difficult. We suggest, however, that MR arthrography has certain diagnostic advantages over conventional MRI.=20

  12. The utility of MR imaging of the shoulder joint: comparison of the MR imaging between conventional MR imaging and arthrographic MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Dong Sik; Ryu, Kyung Nam; Kim, Ihn Sub; Rhee, Yong Girl [Kyunghee Univ., College of Medicine, Seoul (Korea, Republic of)

    1998-09-01

    To evaluate the diagnostic value of MRI of the shoulder. Between January and June 1997, shoulder MRI and arthroscopy were performed in a total of 48 patients with shoulder pain (n=3D30) or shoulder instability (n=3D18). Forty-five were males and three were females; their ages ranged from 16 to 67 (mean 32.5) years. The period between shoulder MRI and arthroscopy was between one and 390 (mean, 42.2) days. Twenty-six patents underwent MR arthrography (AMR), and 22 conventional MRI(CMR). Each image was analyzed for rotator cuff injury, glenoid labral injury, SLAP lesion, and biceps tendon injury. On arthroscopy, one disease was found in 34 patients, two were found in six, three diseases were found in seven, and one patient had four diseases. Arthroscopic diagnosis was as follows:rotator cuff injury, 29;SLAP lesion, 12;glenoid labral injury, 10;biceps tendon injury, 4;subacromial bursitis, 2;chronic synovitis, 1;adhesive capsulitis, 1;superior glenohumeral ligament injury, 1;normal, 1. For rotator cuff injury, the sensitivity of MRI was 65.5% and specificity was 93.0% (AMR:66.7%, 95.8%, CMR:65.2%, 86.4%). For SLAP lesion, sensitivity was 58.3% and specificity was 97.2% (AMR:66.7%, 100%, CMR:50%, 93.8%);for glenoid labral injury, sensitivity was 80.0% and specificity was 89.5% (AMR:85.7%, 84.2%, CMR:66.7%, 94.7%), and for biceps tendon injury, the false negative rate was 100%. In cases involving glenoid labral injury, the diagnostic accuracy of shoulder MRI was relatively high;in rotator cuff injury and SLAP lesion, however, diagnosis was limited, and in biceps tendon injury was difficult. We suggest, however, that MR arthrography has certain diagnostic advantages over conventional MRI.=20.

  13. Diagnosis of pulmonary artery embolism. Comparison of single-source CT and 3rd generation dual-source CT using a dual-energy protocol regarding image quality and radiation dose

    International Nuclear Information System (INIS)

    Petritsch, Bernhard; Kosmala, Aleksander; Gassenmeier, Tobias; Weng, Andreas Max; Veldhoen, Simon; Kunz, Andreas Steven; Bley, Thorsten Alexander

    2017-01-01

    To compare radiation dose, subjective and objective image quality of 3 rd generation dual-source CT (DSCT) and dual-energy CT (DECT) with conventional 64-slice single-source CT (SSCT) for pulmonary CTA. 180 pulmonary CTA studies were performed in three patient cohorts of 60 patients each. Group 1: conventional SSCT 120 kV (ref.); group 2: single-energy DSCT 100 kV (ref.); group 3: DECT 90/Sn150 kV. CTDIvol, DLP, effective radiation dose were reported, and CT attenuation (HU) was measured on three central and peripheral levels. The signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) were calculated. Two readers assessed subjective image quality according to a five-point scale. Mean CTDIvol and DLP were significantly lower in the dual-energy group compared to the SSCT group (p < 0.001 [CTDIvol]; p < 0.001 [DLP]) and the DSCT group (p = 0.003 [CTDIvol]; p = 0.003 [DLP]), respectively. The effective dose in the DECT group was 2.79 ± 0.95 mSv and significantly smaller than in the SSCT group (4.60 ± 1.68 mSv, p < 0.001) and the DSCT group (4.24 ± 2.69 mSv, p = 0.003). The SNR and CNR were significantly higher in the DSCT group (p < 0.001). Subjective image quality did not differ significantly among the three protocols and was rated good to excellent in 75 % (135/180) of cases with an inter-observer agreement of 80 %. Dual-energy pulmonary CTA protocols of 3 rd generation dual-source scanners allow for significant reduction of radiation dose while providing excellent image quality and potential additional information by means of perfusion maps. Dual-energy CT with 90/Sn150 kV configuration allows for significant dose reduction in pulmonary CTA. Subjective image quality was similar among the three evaluated CT-protocols (64-slice SSCT, single-energy DSCT, 90/Sn150 kV DECT) and was rated good to excellent in 75% of cases. Dual-energy CT provides potential additional information by means of iodine distribution maps.

  14. Diagnosis of pulmonary artery embolism. Comparison of single-source CT and 3{sup rd} generation dual-source CT using a dual-energy protocol regarding image quality and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Petritsch, Bernhard; Kosmala, Aleksander; Gassenmeier, Tobias; Weng, Andreas Max; Veldhoen, Simon; Kunz, Andreas Steven; Bley, Thorsten Alexander [Univ. Hospital Wuerzburg (Germany). Inst. of Diagnostic and Interventional Radiology

    2017-06-15

    To compare radiation dose, subjective and objective image quality of 3 rd generation dual-source CT (DSCT) and dual-energy CT (DECT) with conventional 64-slice single-source CT (SSCT) for pulmonary CTA. 180 pulmonary CTA studies were performed in three patient cohorts of 60 patients each. Group 1: conventional SSCT 120 kV (ref.); group 2: single-energy DSCT 100 kV (ref.); group 3: DECT 90/Sn150 kV. CTDIvol, DLP, effective radiation dose were reported, and CT attenuation (HU) was measured on three central and peripheral levels. The signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) were calculated. Two readers assessed subjective image quality according to a five-point scale. Mean CTDIvol and DLP were significantly lower in the dual-energy group compared to the SSCT group (p < 0.001 [CTDIvol]; p < 0.001 [DLP]) and the DSCT group (p = 0.003 [CTDIvol]; p = 0.003 [DLP]), respectively. The effective dose in the DECT group was 2.79 ± 0.95 mSv and significantly smaller than in the SSCT group (4.60 ± 1.68 mSv, p < 0.001) and the DSCT group (4.24 ± 2.69 mSv, p = 0.003). The SNR and CNR were significantly higher in the DSCT group (p < 0.001). Subjective image quality did not differ significantly among the three protocols and was rated good to excellent in 75 % (135/180) of cases with an inter-observer agreement of 80 %. Dual-energy pulmonary CTA protocols of 3 rd generation dual-source scanners allow for significant reduction of radiation dose while providing excellent image quality and potential additional information by means of perfusion maps. Dual-energy CT with 90/Sn150 kV configuration allows for significant dose reduction in pulmonary CTA. Subjective image quality was similar among the three evaluated CT-protocols (64-slice SSCT, single-energy DSCT, 90/Sn150 kV DECT) and was rated good to excellent in 75% of cases. Dual-energy CT provides potential additional information by means of iodine distribution maps.

  15. Evaluation of living liver transplant donors: method for precise anatomic definition by using a dedicated contrast-enhanced MR imaging protocol.

    Science.gov (United States)

    Sahani, Dushyant; D'souza, Roy; Kadavigere, Rajagopal; Hertl, Martin; McGowan, Jennifer; Saini, Sanjay; Mueller, Peter R

    2004-01-01

    Liver transplantation from a living donor involves removal of part of the donor liver in a fashion that does not endanger its vascular supply or metabolic function. The radiologist plays an important role in evaluation of the living donor to define the conditions under which graft donation is contraindicated and to identify anatomic variations that may alter the surgical approach. In the past, diagnostic work-up of the donor involved costly and invasive tests. Currently, dynamic contrast material-enhanced computed tomography and magnetic resonance (MR) imaging are the imaging tests performed, each of which has advantages and limitations. MR imaging performed with liver-specific and extravascular contrast agents may be used as a single imaging test for comprehensive noninvasive evaluation of living liver transplant donors. MR imaging provides valuable information about variations in the vascular and biliary anatomy and allows evaluation of the hepatic parenchyma for diffuse or focal abnormalities. Copyright RSNA, 2004

  16. The Use of Cardiac Magnetic Resonance Imaging in the Diagnostic Workup and Treatment of Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Peter Haemers

    2012-01-01

    Full Text Available Atrial fibrillation (AF is the most common cardiac arrhythmia and imposes a huge clinical and economic burden. AF is correlated with an increased morbidity and mortality, mainly due to stroke and heart failure. Cardiovascular imaging modalities, including echocardiography, computed tomography (CT, and cardiovascular magnetic resonance (CMR, play a central role in the workup and treatment of AF. One of the major advantages of CMR is the high contrast to noise ratio combined with good spatial and temporal resolution, without any radiation burden. This allows a detailed assessment of the structure and function of the left atrium (LA. Of particular interest is the ability to visualize the extent of LA wall injury. We provide a focused review of the value of CMR in identifying the underlying pathophysiological mechanisms of AF, its role in stroke prevention and in the guidance of radiofrequency catheter ablation. CMR is a promising technique that could add valuable information for therapeutic decision making in specific subpopulations with AF.

  17. A polarised neutron scattering study of the excitations in the CMR manganite La0.7Ca0.3MnO3

    International Nuclear Information System (INIS)

    Hagen, M.; Dai, P.

    2002-01-01

    Full text: The magnetic excitations in the colossal magnetoresistance (CMR) materials A 1-x B x MnO 3 (A = La, Pr, Nd, B = Ca, Sr) near the optimum doping x = 1/3 show some remarkable features. In a recent unpolarised inelastic neutron scattering experiment on La 0.7 Ca 0.3 MnO 3 Dai et al. discovered that the magnetic excitations (spin waves) appeared to show considerable softening on approaching the Brillouin zone boundary. This softening appeared to occur when the spin wave dispersion relation crossed a number of flat optic phonon branches, and the possibility exists for interaction/hybridisation with the phonons. In order to separate the magnetic spin waves from the lattice dynamical phonons we have carried out an inelastic polarised neutron scattering study using the IN20 triple axis spectrometer at the Institut Laue Langevin, Grenoble, France. Because La 0.7 Ca 0.3 MnO 3 is a ferromagnet and our principle aim is to separate magnetic from lattice dynamical excitations we have been able to use a novel 'half-polarised' configuration for the spectrometer, originally developed by Holden and Stirling, which boosts the signal by a factor of ∼ 10x. The technique used and the results for La 0.7 Ca 0.3 MnO 3 will be described

  18. A giant enhancement of CMR in Eu{sub 0.6}Ca{sub 0.4}B{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Glushkov, V V; Bogach, A V; Demishev, S V; Sluchanko, N E [A.M.Prokhorov General Physics Institute of RAS, 38, Vavilov str., Moscow 119991 (Russian Federation); Anisimov, M A [Moscow Institute of Physics and Technology, 9, Institutskii per., Dolgoprudny, Moscow Region 141700 (Russian Federation); Churkin, O A; Kuznetsov, A V [Moscow Engineering Physics Institute, 31, Kashirskoe Shosse, Moscow 115409 (Russian Federation); Filipov, V B; Levchenko, A V; Shitsevalova, N Yu [I. Frantsevich Institute for Problems of Materials Science NAS, 3, Krzhyzhanovsky str., Kiev 03680 (Ukraine); Flachbart, K, E-mail: glushkov@lt.gpi.r [Centre of Low Temperature Physics, IEP SAS and IPS FS UPJS, Kosice SK-04001 (Slovakia)

    2010-01-15

    The transport and magnetic properties of Eu{sub 0.6}Ca{sub 0.4}B{sub 6} single crystals have been studied at temperatures 1.8-300 K in magnetic fields up to 80 kOe. It was found that lowering of temperature results in a drastic increase of magnetoresistance up to the values of {rho}(0)/{rho}(H){approx}7{center_dot}10{sup 5} detected below 6K. The Hall and Seebeck effect measurements showed that colossal magnetoresistance (CMR) observed in Eu{sub 0.6}Ca{sub 0.4}B{sub 6} is accompanied by a crossover from hole-like to electron-like regime of charge transport induced by applied magnetic field. Hall mobility values {mu}{sub H{approx}}200-350 cm{sup 2}/(Vs) estimated for the high conductive state of Eu{sub 0.6}Ca{sub 0.4}B{sub 6} in the presence of strong substitutional disorder were proved to be comparable with these ones measured for undoped EuB{sub 6}. The anomalous behaviour of transport and magnetic parameters is discussed in terms of metal-insulator transition earlier predicted for this low carrier density system within double exchange model by V M Pereira et al., Phys. Rev. Lett. 93 147202 (2004).

  19. DIFFUSIVE-Magnetoresistance(DMR) Proton(PMR)/Hydrogen-ion WATER: PRE-``Fert''/``Grunberg'' GMR[and CMR]: Quo-Vadis ``Honesty''???: PLAGIARISM!!!

    Science.gov (United States)

    Fart, Albart; Gruntbug, Peter; Siegel, Edward

    2011-03-01

    Proton/Hydrogen-ion Diffusive-Magnetoresistance(DMR) of Siegel[APS March-Mtgs.(70s)] based upon Siegel[Int'l. Conf. Mag.-Alloys and Oxides("ICMAO"), The Technion(77); J. Mag. Mag. Mtls. 7, 312(78)] FIRST experimental-discovery of GMR and FIRST theoretical prediction of CMR[ibid. 7, 338 (78)], facilitates NEW water production in global-warming exacerbated dry arid/semi-arid regions: Only HYDROGEN is/can be "FLYING-WATER"!!! (aka "chemical-rain-in-pipelines"). EMET/TRUTH-in-the-``SEANCES'', would-be "Sciences": C. Perelman-Corredoira [Against the Tide(07)] featuring Martin-Bradshaw ["Healing the SHAME That BINDS You"(80s)] systemic sociological-dysfunctionality(S-D), and Grigory Perelman's HEROIC ETHICS (refusal of both pure-maths Poincare-conjecture proof 2007 Fields-medal and 2010 Clay-Institute so-called/media-hyped/P.Red/spin-doctored millennium-prize million-dollar would-be award, militates as well in the current "SEANCE" of physics/maths politics/media-hype/P.R /spin-doctoring VS. Siegel FIRST experimental GMR a never-acknowledged full decade PRE-"Fert"(88) /"Grunberg(89)" ``Phales-GroPE''/Thompson-CSF/ KFZ-JEWlich 2007 physics Wolf/Japan/Nobel-prizes!!!

  20. Disappearance of myocardial perfusion defects on prone SPECT imaging: Comparison with cardiac magnetic resonance imaging in patients without established coronary artery disease

    Directory of Open Access Journals (Sweden)

    Hedén Bo

    2009-08-01

    Full Text Available Abstract Background It is of great clinical importance to exclude myocardial infarction in patients with suspected coronary artery disease who do not have stress-induced ischemia. The diagnostic use of myocardial perfusion single-photon emission computed tomography (SPECT in this situation is sometimes complicated by attenuation artifacts that mimic myocardial infarction. Imaging in the prone position has been suggested as a method to overcome this problem. Methods In this study, 52 patients without known prior infarction and no stress-induced ischemia on SPECT imaging were examined in both supine and prone position. The results were compared with cardiac magnetic resonance imaging (CMR with delayed-enhancement technique to confirm or exclude myocardial infarction. Results There were 63 defects in supine-position images, 37 of which disappeared in the prone position. None of the 37 defects were associated with myocardial infarction by CMR, indicating that all of them represented attenuation artifacts. Of the remaining 26 defects that did not disappear on prone imaging, myocardial infarction was confirmed by CMR in 2; the remaining 24 had no sign of ischemic infarction but 2 had other kinds of myocardial injuries. In 3 patients, SPECT failed to detect small scars identified by CMR. Conclusion Perfusion defects in the supine position that disappeared in the prone position were caused by attenuation, not myocardial infarction. Hence, imaging in the prone position can help to rule out ischemic heart disease for some patients admitted for SPECT with suspected but not documented ischemic heart disease. This would indicate a better prognosis and prevent unnecessary further investigations and treatment.

  1. A fast, noniterative approach for accelerated high-temporal resolution cine-CMR using dynamically interleaved streak removal in the power-spectral encoded domain with low-pass filtering (DISPEL) and modulo-prime spokes (MoPS).

    Science.gov (United States)

    Kawaji, Keigo; Patel, Mita B; Cantrell, Charles G; Tanaka, Akiko; Marino, Marco; Tamura, Satoshi; Wang, Hui; Wang, Yi; Carroll, Timothy J; Ota, Takeyoshi; Patel, Amit R

    2017-07-01

    To introduce a pair of accelerated non-Cartesian acquisition principles that when combined, exploit the periodicity of k-space acquisition, and thereby enable acquisition of high-temporal cine Cardiac Magnetic Resonance (CMR). The mathematical formulation of a noniterative, undersampled non-Cartesian cine acquisition and reconstruction is presented. First, a low-pass filtering step that exploits streaking artifact redundancy is provided (i.e., Dynamically Interleaved Streak removal in the Power-spectrum Encoded domain with Low-pass filtering [DISPEL]). Next, an effective radial acquisition for the DISPEL approach that exploits the property of prime numbers is described (i.e., Modulo-Prime Spoke [MoPS]). Both DISPEL and MoPS are examined using numerical simulation of a digital heart phantom to show that high-temporal cine-CMR is feasible without removing physiologic motion vs aperiodic interleaving using Golden Angles. The combined high-temporal cine approach is next examined in 11 healthy subjects for a time-volume curve assessment of left ventricular systolic and diastolic performance vs conventional Cartesian cine-CMR reference. The DISPEL method was first shown using simulation under different streak cycles to allow separation of undersampled radial streaking artifacts from physiologic motion with a sufficiently frequent streak-cycle interval. Radial interleaving with MoPS is next shown to allow interleaves with pseudo-Golden-Angle variants, and be more compatible with DISPEL against irrational and nonperiodic rotation angles, including the Golden-Angle-derived rotations. In the in vivo data, the proposed method showed no statistical difference in the systolic performance, while diastolic parameters sensitive to the cine's temporal resolution were statistically significant (P cine). We demonstrate a high-temporal resolution cine-CMR using DISPEL and MoPS, whose streaking artifact was separated from physiologic motion. © 2017 American Association of Physicists

  2. Magnetic microstructure of CMR La{sub 0.7}Sr{sub 0.3}MnO{sub 3} thin films grown on (001)LaAlO{sub 3} substrates studied by X-ray diffraction and magnetic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Desfeux, R.; Bailleul, S. [Universite d' Artois, Lens (France). Lab. de Physico-Chimie des Interfaces et Applications; Prellier, W.; Haghiri-Gosnet, A.M. [Lab. CRISMAT-ISMRA, Univ. de Caen (France)

    2001-07-01

    Colossal magnetoresistive (CMR) La{sub 0.7}Sr{sub 0.3}MnO{sub 3} (LSMO) thin films have been deposited by laser ablation on pseudo-cubic LaAlO{sub 3} (001) substrates. The ferromagnetic state of these films at room temperature has been evidenced by SQUID measurements. Depending on the growth conditions (mostly the synthesis temperature), out-of-plane parameters varying from of 3.919 A or 4.002 A are measured on the X-ray diffraction (XRD) patterns. Using magnetic force microscopy (MFM), black and white contrasts characteristics of films with an out-of-plane magnetization are imaged. However, depending on the out-of-plane parameter, two out-of-plane magnetic patterns are showed. On samples with the out-of-plane parameter of 3.919 A, a ''maze-like - bubble'' pattern is imaged while on samples with a larger out-of-plane value of 4.002 A, large domains with a diameter of about 5 {mu}m are evidenced. We conclude that the magnetic microstructure of LSMO films deposited on LaAlO{sub 3} substrates is strongly influenced by the growth conditions and that the magnetic domains shape can be correlate to the out-of-plane parameter of the film. (orig.)

  3. Post mortem magnetic resonance imaging in the fetus, infant and child: A comparative study with conventional autopsy (MaRIAS Protocol

    Directory of Open Access Journals (Sweden)

    Thayyil Sudhin

    2011-12-01

    Full Text Available Abstract Background Minimally invasive autopsy by post mortem magnetic resonance (MR imaging has been suggested as an alternative for conventional autopsy in view of the declining consented autopsy rates. However, large prospective studies rigorously evaluating the accuracy of such an approach are lacking. We intend to compare the accuracy of a minimally invasive autopsy approach using post mortem MR imaging with that of conventional autopsy in fetuses, newborns and children for detection of the major pathological abnormalities and/or determination of the cause of death. Methods/Design We recruited 400 consecutive fetuses, newborns and children referred for conventional autopsy to one of the two participating hospitals over a three-year period. We acquired whole body post mortem MR imaging using a 1.5 T MR scanner (Avanto, Siemens Medical Solutions, Enlargen, Germany prior to autopsy. The total scan time varied between 90 to 120 minutes. Each MR image was reported by a team of four specialist radiologists (paediatric neuroradiology, paediatric cardiology, paediatric chest & abdominal imaging and musculoskeletal imaging, blinded to the autopsy data. Conventional autopsy was performed according to the guidelines set down by the Royal College of Pathologists (UK by experienced paediatric or perinatal pathologists, blinded to the MR data. The MR and autopsy data were recorded using predefined categorical variables by an independent person. Discussion Using conventional post mortem as the gold standard comparator, the MR images will be assessed for accuracy of the anatomical morphology, associated lesions, clinical usefulness of information and determination of the cause of death. The sensitivities, specificities and predictive values of post mortem MR alone and MR imaging along with other minimally invasive post mortem investigations will be presented for the final diagnosis, broad diagnostic categories and for specific diagnosis of each system

  4. MR efficiency using automated MRI-desktop eProtocol

    Science.gov (United States)

    Gao, Fei; Xu, Yanzhe; Panda, Anshuman; Zhang, Min; Hanson, James; Su, Congzhe; Wu, Teresa; Pavlicek, William; James, Judy R.

    2017-03-01

    MRI protocols are instruction sheets that radiology technologists use in routine clinical practice for guidance (e.g., slice position, acquisition parameters etc.). In Mayo Clinic Arizona (MCA), there are over 900 MR protocols (ranging across neuro, body, cardiac, breast etc.) which makes maintaining and updating the protocol instructions a labor intensive effort. The task is even more challenging given different vendors (Siemens, GE etc.). This is a universal problem faced by all the hospitals and/or medical research institutions. To increase the efficiency of the MR practice, we designed and implemented a web-based platform (eProtocol) to automate the management of MRI protocols. It is built upon a database that automatically extracts protocol information from DICOM compliant images and provides a user-friendly interface to the technologists to create, edit and update the protocols. Advanced operations such as protocol migrations from scanner to scanner and capability to upload Multimedia content were also implemented. To the best of our knowledge, eProtocol is the first MR protocol automated management tool used clinically. It is expected that this platform will significantly improve the radiology operations efficiency including better image quality and exam consistency, fewer repeat examinations and less acquisition errors. These protocols instructions will be readily available to the technologists during scans. In addition, this web-based platform can be extended to other imaging modalities such as CT, Mammography, and Interventional Radiology and different vendors for imaging protocol management.

  5. 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

  6. Comparing a novel automatic 3D method for LGE-CMR quantification of scar size with established methods.

    Science.gov (United States)

    Woie, Leik; Måløy, Frode; Eftestøl, Trygve; Engan, Kjersti; Edvardsen, Thor; Kvaløy, Jan Terje; Ørn, Stein

    2014-02-01

    Current methods for the estimation of infarct size by late-enhanced cardiac magnetic imaging are based upon 2D analysis that first determines the size of the infarction in each slice, and thereafter adds the infarct sizes from each slice to generate a volume. We present a novel, automatic 3D method that estimates infarct size by a simultaneous analysis of all pixels from all slices. In a population of 54 patients with ischemic scars, the infarct size estimated by the automatic 3D method was compared with four established 2D methods. The new 3D method defined scar as the sum of all pixels with signal intensity (SI) ≥35 % of max SI from the complete myocardium, border zone: SI 35-50 % of max SI and core as SI ≥50 % of max SI. The 3D method yielded smaller infarct size (-2.8 ± 2.3 %) and core size (-3.0 ± 1.7 %) than the 2D method most similar to ours. There was no difference in the size of the border zone (0.2 ± 1.4 %). The 3D method demonstrated stronger correlations between scar size and left ventricular (LV) remodelling parameters (LV ejection fraction: r = -0.71, p 3D automatic method is without the need for manual demarcation of the scar; it is less time-consuming and has a stronger correlation with remodelling parameters compared with existing methods.

  7. Cost-effectiveness of functional cardiac imaging in the diagnostic work-up of coronary heart disease.

    Science.gov (United States)

    Pletscher, Mark; Walker, Simon; Moschetti, Karine; Pinget, Christophe; Wasserfallen, Jean-Blaise; Greenwood, John P; Schwitter, Juerg; Girardin, François R

    2016-07-01

    The aim of this study was to assess the cost-effectiveness of eight common diagnostic work-up strategies for coronary heart disease (CHD) in patients with stable angina symptoms in Switzerland. A decision analytical model was used to perform a cost-effectiveness comparison of eight common multitest strategies to diagnose CHD using combinations of four diagnostic techniques: exercise treadmill test (ETT), single-photon emission computed tomography (SPECT), cardiac magnetic resonance imaging (CMR), and coronary angiography (CA). We used a Markov state transition model to extrapolate the results over a life-time horizon, from a third-party payer perspective. We used a CHD prevalence rate of 39% in patients and a base-case scenario with 60-year-old male patients with intermediate symptom severity Canadian Cardiovascular Society grading of angina pectoris 2 and at least one cardiovascular (CV) risk factor but without a history of myocardial infarction and without need for revascularization. Among the eight work-up strategies, one strategy was dominant, i.e. least costly and most effective: ETT followed by CMR if the ETT result was inconclusive and then CA if the CMR result was positive or inconclusive. The CMR features a favourable balance between false-negative diagnoses, associated with an elevated risk of CV events, and false-positive diagnoses, leading to unnecessary CA and related mortality. Key parameters guiding the diagnostic strategy are the prevalence of CHD in patients with angina symptoms and the diagnostic costs of CA and CMR. Cardiac magnetic resonance imaging appears to be a cost-effective work-up strategy compared with other regimens using SPECT or direct CA. Cardiac magnetic resonance imaging should be more widely recommended as a diagnostic procedure for patients with suspected angina symptoms.

  8. Quantification of pulmonary regurgitation and prediction of pulmonary valve replacement by echocardiography in patients with congenital heart defects in comparison to cardiac magnetic resonance imaging.

    Science.gov (United States)

    Dellas, Claudia; Kammerer, Laura; Gravenhorst, Verena; Lotz, Joachim; Paul, Thomas; Steinmetz, Michael

    2018-04-01

    Pulmonary regurgitation (PR) is common in patients with congenital heart defects (CHD) and contributes to morbidity and mortality in the long-term. We investigated in this retrospective analysis whether readily accessible echocardiographic parameters are useful for quantification of PR and for predicting pulmonary valve replacement (PVR) in comparison to the gold-standard phase contrast (PC) flow measurements from cardiovascular magnetic resonance (CMR). Continuous wave (CW) Doppler and colour flow images in echocardiograms from 53 patients with CHD were analysed. Slope and jet-to-RVOT ratio correlated significantly with CMR-assessed regurgitation fraction (RF), whereas pressure half time (PHT) showed an inverse correlation. Patients with mild PR in CMR had significantly higher PHT, lower slope and jet-to-RVOT ratio than patients with moderate or severe regurgitation. The AUC regarding PR severity was 0.778 for PHT (95% CI, 0.649-0.907; P = 0.007 for CMR-RF ≤ 35%), 0.744 for slope (95% CI, 0.603-0.885; P = 0.017 for CMR-RF > 35%) and 0.652 for jet-to-RVOT ratio (95% CI, 0.473-0.860; P = 0.168 for CMR-RF > 35%). The optimal cut-off values calculated from ROC analysis were 95 ms for PHT and 4.9 m/s 2 for slope. In logistic regression analysis, slope emerged as the most valuable parameter for predicting the indication for PVR (OR 12.9, 95% CI, 1.8-90.9, P = 0.010). In conclusion, echocardiographic assessment of PR was feasible. Both parameters, PHT and in particular slope, were predictors for PVR. Thus, echocardiography appears appropriate in the management of patients with PR.

  9. Comparison of Image Processing Techniques for Nonviable Tissue Quantification in Late Gadolinium Enhancement Cardiac Magnetic Resonance Images.

    Science.gov (United States)

    Carminati, M Chiara; Boniotti, Cinzia; Fusini, Laura; Andreini, Daniele; Pontone, Gianluca; Pepi, Mauro; Caiani, Enrico G

    2016-05-01

    The aim of this study was to compare the performance of quantitative methods, either semiautomated or automated, for left ventricular (LV) nonviable tissue analysis from cardiac magnetic resonance late gadolinium enhancement (CMR-LGE) images. The investigated segmentation techniques were: (i) n-standard deviations thresholding; (ii) full width at half maximum thresholding; (iii) Gaussian mixture model classification; and (iv) fuzzy c-means clustering. These algorithms were applied either in each short axis slice (single-slice approach) or globally considering the entire short-axis stack covering the LV (global approach). CMR-LGE images from 20 patients with ischemic cardiomyopathy were retrospectively selected, and results from each technique were assessed against manual tracing. All methods provided comparable performance in terms of accuracy in scar detection, computation of local transmurality, and high correlation in scar mass compared with the manual technique. In general, no significant difference between single-slice and global approach was noted. The reproducibility of manual and investigated techniques was confirmed in all cases with slightly lower results for the nSD approach. Automated techniques resulted in accurate and reproducible evaluation of LV scars from CMR-LGE in ischemic patients with performance similar to the manual technique. Their application could minimize user interaction and computational time, even when compared with semiautomated approaches.

  10. Rapid, low-cost MR imaging protocol to document central nervous system and sinus abnormalities prior to pediatric hematopoietic stem cell transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Eliane D.; Barbosa, Felipe G. de; Szarf, Gilberto; Lederman, Henrique M. [Universidade Federal de Sao Paulo, Department of Diagnostic Imaging, Sao Paulo (Brazil); Seber, Adriana; Ginani, Valeria C.; Carlesse, Fabianne C.; Gouvea, Roseane V.; Zecchin, Victor G.; Carvalho, Cinthya R. [Universidade Federal de Sao Paulo, Division of Pediatric Oncology, Department of Pediatrics, Sao Paulo (Brazil)

    2011-06-15

    Patients undergoing bone marrow transplant (BMT) are at risk for infectious complications, including those of the sinus. Central nervous system (CNS) abnormalities related to the chemotherapy or radiation that the patient received for the treatment of underlying malignancy or to transplant-related effects are also commonly seen. The only effective way to differentiate pre- and post-transplant causes is to have a baseline evaluation prior to the admission for transplant. The current method used to evaluate these patients is head CT. However, CT is not accurate to demonstrate CNS abnormalities and exposes the patient to radiation. MRI, despite better sensitivity for white matter abnormalities, has not been routinely used because of the higher cost and longer duration of the exam. Therefore, we designed a fast, low-cost and radiation-free MRI-based protocol to simultaneously evaluate sinus and brain abnormalities. (orig.)

  11. Poster — Thur Eve — 06: Dose assessment of cone beam CT imaging protocols as part of SPECT/CT examinations

    Energy Technology Data Exchange (ETDEWEB)

    Tonkopi, E; Ross, AA [Department of Diagnostic Imaging, Queen Elizabeth II Health Sciences Centre, CDHA (Canada); Department of Radiology, Dalhousie University (Canada)

    2014-08-15

    Purpose: To assess radiation dose from the cone beam CT (CBCT) component of SPECT/CT studies and to compare with other CT examinations performed in our institution. Methods: We used an anthropomorphic chest phantom and the 6 cc ion chamber to measure entrance breast dose for several CBCT and diagnostic CT acquisition protocols. The CBCT effective dose was calculated with ImPACT software; the CT effective dose was evaluated from the DLP value and conversion factor, dependent on the anatomic region. The RADAR medical procedure radiation dose calculator was used to assess the nuclear medicine component of exam dose. Results: The entrance dose to the breast measured with the anthropomorphic phantom was 0.48 mGy and 9.41 mGy for cardiac and chest CBCT scans; and 4.59 mGy for diagnostic thoracic CT. The effective doses were 0.2 mSv, 3.2 mSv and 2.8 mSv respectively. For a small patient represented by the anthropomorphic phantom, the dose from the diagnostic CT was lower than from the CBCT scan, as a result of the exposure reduction options available on modern CT scanners. The CBCT protocols used the same fixed scanning techniques. The diagnostic CT dose based on the patient data was 35% higher than the phantom dose. For most SPECT/CT studies the dose from the CBCT component was comparable with the dose from the radiopharmaceutical. Conclusions: The patient radiation dose from the cone beam CT scan can be higher than that from a diagnostic CT and should be taken into consideration in evaluating total SPECT/CT patient dose.

  12. Sincalide - the final protocol

    International Nuclear Information System (INIS)

    Clarke, E.A.; Notghi, A.; Hesslewood, S.R.; Harding, L.K.

    2002-01-01

    Full text: HIDA biliary studies examine the gallbladder (GB) to give a percentage ejection fraction (EF). Porcine CCK was an accepted agent for stimulating the GB prior to being withdrawn in the UK from 1998. Sincalide (a synthetic CCK) was the suggested replacement. We have tried many administration regimes in an attempt to get results comparable with our established CCK protocols. Dose concentration and length of infusion times have been studied. Initially a dose of 10 ngm/kg/min given over 2 minutes (manufacturer's recommended dose) was used. This gave falsely low ejection fractions. The dose was reduced to 3 ngm/kg/min over 3 minutes as it was felt the higher dose may be causing constriction of the sphincter of Oddi. This gave a slight improvement with 22 % of patients having normal EF (>35 %). The length of infusion was extended to 15 minutes and the dose concentration reduced again to 0.6 ngm/kg/min. 62 % of patients had a normal EF. However, on many of the curves the gallbladder was still contracting on completion of the 15 minute infusion and began to refill immediately after stopping Sincalide. A further change of protocol was indicated. The infusion time was extended to 30 minutes and the dose concentration per minute kept the same. Imaging began at 30 minutes post HIDA injection and continued for a total of 50 minutes. Sincalide infusion began at 35 minutes if a GB was visualized. This protocol has been performed on 17 patients. 53 % of these had a normal result (comparable with a normal rate of 40 % previously established with CCK) with a mean EF of 60 %. The mean EF of patients with abnormal studies was 15 %. Curves showed a plateau by 30 minutes in 94 % of patients indicating that gallbladder contraction was complete. No normal range is available so results were compared with ultrasound (US). All patients who had an abnormal US scan also had abnormal HIDA results. Three patients had a normal US scan and abnormal HIDA study. These are currently

  13. Textural analysis of early-phase spatiotemporal changes in contrast enhancement of breast lesions imaged with an ultrafast DCE-MRI protocol

    NARCIS (Netherlands)

    Milenkovic, J.; Dalmis, M.U.; Zgajnar, J.; Platel, B.

    2017-01-01

    PURPOSE: New ultrafast view-sharing sequences have enabled breast dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to be performed at high spatial and temporal resolution. The aim of this study is to evaluate the diagnostic potential of textural features that quantify the

  14. Design and rationale of the MR-INFORM study: stress perfusion cardiovascular magnetic resonance imaging to guide the management of patients with stable coronary artery disease

    Directory of Open Access Journals (Sweden)

    Hussain Shazia T

    2012-09-01

    Full Text Available Abstract Background In patients with stable coronary artery disease (CAD, decisions regarding revascularisation are primarily driven by the severity and extent of coronary luminal stenoses as determined by invasive coronary angiography. More recently, revascularisation decisions based on invasive fractional flow reserve (FFR have shown improved event free survival. Cardiovascular magnetic resonance (CMR perfusion imaging has been shown to be non-inferior to nuclear perfusion imaging in a multi-centre setting and superior in a single centre trial. In addition, it is similar to invasively determined FFR and therefore has the potential to become the non-invasive test of choice to determine need for revascularisation. Trial design The MR-INFORM study is a prospective, multi-centre, randomised controlled non-inferiority, outcome trial. The objective is to compare the efficacy of two investigative strategies for the management of patients with suspected CAD. Patients presenting with stable angina are randomised into two groups: 1 The FFR-INFORMED group has subsequent management decisions guided by coronary angiography and fractional flow reserve measurements. 2 The MR-INFORMED group has decisions guided by stress perfusion CMR. The primary end-point will be the occurrence of major adverse cardiac events (death, myocardial infarction and repeat revascularisation at one year. Clinical trials.gov identifier NCT01236807. Conclusion MR INFORM will assess whether an initial strategy of CMR perfusion is non-inferior to invasive angiography supplemented by FFR measurements to guide the management of patients with stable coronary artery disease. Non-inferiority of CMR perfusion imaging to the current invasive reference standard (FFR would establish CMR perfusion imaging as an attractive non-invasive alternative to current diagnostic pathways.

  15. Cardiac and pericardial tumors: A potential application of positron emission tomography-magnetic resonance imaging.

    Science.gov (United States)

    Fathala, Ahmed; Abouzied, Mohei; AlSugair, Abdul-Aziz

    2017-07-26

    Cardiac and pericardial masses may be neoplastic, benign and malignant, non-neoplastic such as thrombus or simple pericardial cysts, or normal variants cardiac structure can also be a diagnostic challenge. Currently, there are several imaging modalities for diagnosis of cardiac masses; each technique has its inherent advantages and disadvantages. Echocardiography, is typically the initial test utilizes in such cases, Echocardiography is considered the test of choice for evaluation and detection of cardiac mass, it is widely available, portable, with no ionizing radiation and provides comprehensive evaluation of cardiac function and valves, however, echocardiography is not very helpful in many cases such as evaluation of extracardiac extension of mass, poor tissue characterization, and it is non diagnostic in some cases. Cross sectional imaging with cardiac computed tomography provides a three dimensional data set with excellent spatial resolution but utilizes ionizing radiation, intravenous iodinated contrast and relatively limited functional evaluation of the heart. Cardiac magnetic resonance imaging (CMR) has excellent contrast resolution that allows superior soft tissue characterization. CMR offers comprehensive evaluation of morphology, function, tissue characterization. The great benefits of CMR make CMR a highly useful tool in the assessment of cardiac masses. (Fluorine 18) fluorodeoxygluocse (FDG) positron emission tomography (PET) has become a corner stone in several oncological application such as tumor staging, restaging, treatment efficiency, FDG is a very useful imaging modality in evaluation of cardiac masses. A recent advance in the imaging technology has been the development of integrated PET-MRI system that utilizes the advantages of PET and MRI in a single examination. FDG PET-MRI provides complementary information on evaluation of cardiac masses. The purpose of this review is to provide several clinical scenarios on the incremental value of PET

  16. Correlation between myocardial fibrosis and the occurrence of atrial fibrillation in hypertrophic cardiomyopathy: A cardiac magnetic resonance imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Pujadas, S., E-mail: sandrapujadas@gmail.co [Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Vidal-Perez, R. [Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Hidalgo, A. [Radiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Leta, R.; Carreras, F.; Barros, A. [Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Bayes-Genis, A. [Cardiomyopathy and Cardiac Transplant Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Subirana, M.T. [Congenital Heart Disease Unit, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Pons-Llado, Guillem [Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain)

    2010-08-15

    Cardiac magnetic resonance imaging (CMR) in hypertrophic cardiomyopathy (HCM) often shows delayed contrast enhancement (DE) representing regions of focal myocardial fibrosis. Atrial fibrillation (AF) is a commonly reported complication of HCM. We determined the relationship between the presence of left ventricular myocardial fibrosis (LVMF) detected by DE-CMR and the occurrence AF in a series of patients with HCM. 67 patients with HCM (47 males; mean age 50.1 {+-} 18.5 years) were studied by CMR measuring mass of LVMF, left ventricular mass, volume and function, and left atrial (LA) area. AF was present in 17 (25%) patients. LVMF was observed in 57% of patients. AF was significantly more frequent in patients who also showed LVMF, compared with the group without LVMF (42.1% vs. 3.4%, respectively; p < 0.0001). LA size was larger in patients showing DE (LA area: 37.4 {+-} 11.1 vs. 25.9 {+-} 6.8 cm{sup 2}; respectively, p = 0.0001). AF in HCM is related with myocardial fibrosis detected by DE-CMR and dilatation of the LA. This fact adds to the proven adverse prognostic value of myocardial fibrosis in HCM, thus, reinforcing the usefulness of this technique in the assessment of these patients.

  17. Correlation between myocardial fibrosis and the occurrence of atrial fibrillation in hypertrophic cardiomyopathy: A cardiac magnetic resonance imaging study

    International Nuclear Information System (INIS)

    Pujadas, S.; Vidal-Perez, R.; Hidalgo, A.; Leta, R.; Carreras, F.; Barros, A.; Bayes-Genis, A.; Subirana, M.T.; Pons-Llado, Guillem

    2010-01-01

    Cardiac magnetic resonance imaging (CMR) in hypertrophic cardiomyopathy (HCM) often shows delayed contrast enhancement (DE) representing regions of focal myocardial fibrosis. Atrial fibrillation (AF) is a commonly reported complication of HCM. We determined the relationship between the presence of left ventricular myocardial fibrosis (LVMF) detected by DE-CMR and the occurrence AF in a series of patients with HCM. 67 patients with HCM (47 males; mean age 50.1 ± 18.5 years) were studied by CMR measuring mass of LVMF, left ventricular mass, volume and function, and left atrial (LA) area. AF was present in 17 (25%) patients. LVMF was observed in 57% of patients. AF was significantly more frequent in patients who also showed LVMF, compared with the group without LVMF (42.1% vs. 3.4%, respectively; p 2 ; respectively, p = 0.0001). AF in HCM is related with myocardial fibrosis detected by DE-CMR and dilatation of the LA. This fact adds to the proven adverse prognostic value of myocardial fibrosis in HCM, thus, reinforcing the usefulness of this technique in the assessment of these patients.

  18. Temporal and spatial characteristics of the area at risk investigated using computed tomography and T1-weighted magnetic resonance imaging

    DEFF Research Database (Denmark)

    van der Pals, Jesper; Hammer-Hansen, Sophia; Nielles-Vallespin, Sonia

    2015-01-01

    AIMS: Cardiovascular magnetic resonance (CMR) imaging can measure the myocardial area at risk (AAR), but the technique has received criticism for inadequate validation. CMR commonly depicts an AAR that is wider than the infarct, which in turn would require a lateral perfusion gradient within...... and fluorescent microparticle pathology were used to investigate the AAR in a canine model (n = 10) of ischaemia and reperfusion. AAR size by CMR correlated well with CT (R(2) = 0.80), microsphere blood flow (R(2) = 0.80), and pathology (R(2) = 0.74) with good limits of agreement [-0.79 ± 4.02% of the left.......05 ± 0.02 mL/g/min, lateral vs. core, P = 0.001). The transmural extent of MI was lower in the lateral portion of the AAR than the core (28.2 ± 10.2 vs. 17.4 ± 8.4% of the wall, P = 0.001). CONCLUSION: T1-weighted CMR accurately quantifies size of the AAR with excellent agreement compared with three...

  19. Vertical Protocol Composition

    DEFF Research Database (Denmark)

    Groß, Thomas; Mödersheim, Sebastian Alexander

    2011-01-01

    The security of key exchange and secure channel protocols, such as TLS, has been studied intensively. However, only few works have considered what happens when the established keys are actually used—to run some protocol securely over the established “channel”. We call this a vertical protocol.......e., that the combination cannot introduce attacks that the individual protocols in isolation do not have. In this work, we prove a composability result in the symbolic model that allows for arbitrary vertical composition (including self-composition). It holds for protocols from any suite of channel and application...

  20. Feasibility and diagnostic accuracy of Ecg-gated SPECT myocardial perfusion imaging by a two-hour protocol: The Myofast study;Faisabilite et precision diagnostique d'un protocole de scintigraphie myocardique synchronisee a l'ECG en deux heures: l'etude Myofast

    Energy Technology Data Exchange (ETDEWEB)

    Dunet, V.; Costo, S.; Sabatier, R.; Grollier, G.; Bouvard, G.; Agostini, D. [CHU Cote-de-Nacre, Service de medecine nucleaire, 14 - Caen (France)

    2010-04-15

    Aim of the study: To assess the feasibility of early stress and rest myocardial perfusion and function study using a fast {sup 99m}Tc-tetrofosmin gated-SPECT protocol in patients with known coronary artery disease. Materials and methods: Forty-three patients (pts) (37 M, 6 F, mean age 63.8 +- 9.8 years) underwent a {sup 99m}Tc-Tetrofosmin gated-SPECT (Axis Picker-Philips) myocardial study and a coronary angiography (C.A.) within 3 months. Images were acquired (LEHR, eight bins, 40 sec per image) after injection of {sup 99m}Tc-tetrofosmin (200 to 380 MBq) early (15 min) post-stress (36 dipyridamole, two dobutamine and five ergo-metric stress), and at rest after {sup 99m}Tc-tetrofosmin reinjection (600 to 1150 MBq), in a total time not exceeding 2 hours. Processing was performed with Q.G.S. software using the 17-segment model. Pathological study was defined as a summed difference score (SDS) greater than or equal to 4 4, a fixed defect with summed rest score greater than or equal to 4 and/or L.V. dysfunction defined as myocardial stunning (variation between stress and rest L.V.E.F. greater than or equal to 4 5%), stress L.V.E.F. less than or equal to 45% or rest L.V.E.F. less than or equal to 40%. Results were compared with C.A., and stenosis greater than or equal to 4 50% was considered as significant. Results: For 100% the quality of SPECT imaging was good or excellent. For six patients gating was impossible because of arrhythmia. The overall sensitivity, specificity and accuracy were 95%, 50%, and 91%, respectively. The concordance between gated SPECT and C.A. was moderate (kappa = 0.45, S.E. = 0.15). Interestingly, early-gated acquisition permitted to underline left ventricular dysfunction in 11 cases (30%), of whom eight had poly vascular disease. Stunning was detected in six of 37 cases (16%), of whom six had poly vascular disease. Conclusion: A one-day two-hour {sup 99m}Tc-tetrofosmin gated-SPECT protocol to assess left ventricular perfusion and function is

  1. Body packers on your examination table: How helpful are plain x-ray images? A definitive low-dose CT protocol as a diagnosis tool for body packers.

    Science.gov (United States)

    Schulz, B; Grossbach, A; Gruber-Rouh, T; Zangos, S; Vogl, Th J; Eichler, K

    2014-12-01

    To analyze the clinical value and radiation dose of plain x-rays and CT in examining patients suspected of ingesting drug-filled packets. Thirty-eight patients with suspected internal concealment of drug-filled packets who were examined with plain x-rays or CT or both were included in the study. CT studies were performed using low-dose and standard-dose techniques. All radiographic images were analysed by two radiologists regarding identification of the packets and estimating the effective radiation dose from standard- and low-dose CT versus conventional x-ray examinations. Descriptive calculations were made regarding the number and density of packs and radiation dosage. The diagnostic performance of both radiologists with standard- and low-dose CT was calculated by analysing differences in the mean number of packs found. Thirty-one patients were positively identified as body packers with an average of 13 packs (min: n = 1, max: n = 58, total: n = 390); seven patients were not concealing drug packets. X-ray images were taken of 24 patients prior to CT, thus allowing a direct comparison between the two methods. The correct diagnosis was made in 42%, in 33% the radiologists were uncertain, and in 25% of drug packets were either not or wrongly identified. X-ray imaging had a positive predictive value of 20% with a negative predictive value of 81%. A total of 55 CT examinations were performed on all patients with a mean effective dose of 2 mSv (low dose) versus 9.3 mSv (standard dose). The visibility of packets on low-dose CT images compared to high-dose CT was not reduced: the radiologists identified 385 and 381 of the packets, respectively, with no difference regarding the examination technique (p = 0.24 and p = 0.253, respectively). The radiodensity of all drug-filled packets at CT ranged from 26-292 HU (mean 181.2 HU). X-ray imaging of supposed body packers leads to a significant risk of diagnostic errors and additional need for CT. Instead, a single abdominal low

  2. Coronary artery stent mimicking intracardiac thrombus on cardiac magnetic resonance imaging due to signal loss

    DEFF Research Database (Denmark)

    Qayyum, Abbas Ali; Vejlstrup, Niels Grove; Ahtarovski, Kiril Aleksov

    2012-01-01

    Since the introduction of percutaneous coronary intervention for coronary artery disease, thousands of patients have been treated with the implantation of coronary stents. Moreover, several of the patients with coronary stent undergo cardiac magnetic resonance (CMR) imaging every year. This case...... report is of a 77-year-old man who was previously treated with the implantation of a coronary stent in the left circumflex artery. He underwent CMR imaging, which revealed a process 14×21 mm in the left atrium. Cardiac contrast computed tomography did not demonstrate any cardiac pathology. While...... the signal loss on MRI associated with implanted metallic devices is known, we report a case where an implanted coronary stent in the left circumflex artery led to an intracardiac signal loss mimicking intracardiac thrombus/tumor....

  3. Automatic extraction of myocardial mass and volumes using parametric images from dynamic nongated PET

    DEFF Research Database (Denmark)

    Harms, Hendrik Johannes; Hansson, Nils Henrik Stubkjær; Tolbod, Lars Poulsen

    2016-01-01

    Dynamic cardiac positron emission tomography (PET) is used to quantify molecular processes in vivo. However, measurements of left-ventricular (LV) mass and volumes require electrocardiogram (ECG)-gated PET data. The aim of this study was to explore the feasibility of measuring LV geometry using non......-gated dynamic cardiac PET. METHODS: Thirty-five patients with aortic-valve stenosis and 10 healthy controls (HC) underwent a 27-min 11C-acetate PET/CT scan and cardiac magnetic resonance imaging (CMR). HC were scanned twice to assess repeatability. Parametric images of uptake rate K1 and the blood pool were......LV and WT only and an overestimation for LVEF at lower values. Intra- and inter-observer correlations were >0.95 for all PET measurements. PET repeatability accuracy in HC was comparable to CMR. CONCLUSION: LV mass and volumes are accurately and automatically generated from dynamic 11C-acetate PET without...

  4. Body packers on your examination table: How helpful are plain x-ray images? A definitive low-dose CT protocol as a diagnosis tool for body packers

    International Nuclear Information System (INIS)

    Schulz, B.; Grossbach, A.; Gruber-Rouh, T.; Zangos, S.; Vogl, Th. J.; Eichler, K.

    2014-01-01

    Aim: To analyze the clinical value and radiation dose of plain x-rays and CT in examining patients suspected of ingesting drug-filled packets. Materials and methods: Thirty-eight patients with suspected internal concealment of drug-filled packets who were examined with plain x-rays or CT or both were included in the study. CT studies were performed using low-dose and standard-dose techniques. All radiographic images were analysed by two radiologists regarding identification of the packets and estimating the effective radiation dose from standard- and low-dose CT versus conventional x-ray examinations. Descriptive calculations were made regarding the number and density of packs and radiation dosage. The diagnostic performance of both radiologists with standard- and low-dose CT was calculated by analysing differences in the mean number of packs found. Results: Thirty-one patients were positively identified as body packers with an average of 13 packs (min: n = 1, max: n = 58, total: n = 390); seven patients were not concealing drug packets. X-ray images were taken of 24 patients prior to CT, thus allowing a direct comparison between the two methods. The correct diagnosis was made in 42%, in 33% the radiologists were uncertain, and in 25% of drug packets were either not or wrongly identified. X-ray imaging had a positive predictive value of 20% with a negative predictive value of 81%. A total of 55 CT examinations were performed on all patients with a mean effective dose of 2 mSv (low dose) versus 9.3 mSv (standard dose). The visibility of packets on low-dose CT images compared to high-dose CT was not reduced: the radiologists identified 385 and 381 of the packets, respectively, with no difference regarding the examination technique (p = 0.24 and p = 0.253, respectively). The radiodensity of all drug-filled packets at CT ranged from 26–292 HU (mean 181.2 HU). Conclusion: X-ray imaging of supposed body packers leads to a significant risk of diagnostic

  5. Quantification of dopaminergic neurotransmission SPECT studies with 123I-labelled radioligands. A comparison between different imaging systems and data acquisition protocols using Monte Carlo simulation

    International Nuclear Information System (INIS)

    Crespo, Cristina; Aguiar, Pablo; Gallego, Judith; Cot, Albert; Falcon, Carles; Ros, Domenec; Bullich, Santiago; Pareto, Deborah; Sempau, Josep; Lomena, Francisco; Calvino, Francisco; Pavia, Javier

    2008-01-01

    123 I-labelled radioligands are commonly used for single-photon emission computed tomography (SPECT) imaging of the dopaminergic system to study the dopamine transporter binding. The aim of this work was to compare the quantitative capabilities of two different SPECT systems through Monte Carlo (MC) simulation. The SimSET MC code was employed to generate simulated projections of a numerical phantom for two gamma cameras equipped with a parallel and a fan-beam collimator, respectively. A fully 3D iterative reconstruction algorithm was used to compensate for attenuation, the spatially variant point spread function (PSF) and scatter. A post-reconstruction partial volume effect (PVE) compensation was also developed. For both systems, the correction for all degradations and PVE compensation resulted in recovery factors of the theoretical specific uptake ratio (SUR) close to 100%. For a SUR value of 4, the recovered SUR for the parallel imaging system was 33% for a reconstruction without corrections (OSEM), 45% for a reconstruction with attenuation correction (OSEM-A), 56% for a 3D reconstruction with attenuation and PSF corrections (OSEM-AP), 68% for OSEM-AP with scatter correction (OSEM-APS) and 97% for OSEM-APS plus PVE compensation (OSEM-APSV). For the fan-beam imaging system, the recovered SUR was 41% without corrections, 55% for OSEM-A, 65% for OSEM-AP, 75% for OSEM-APS and 102% for OSEM-APSV. Our findings indicate that the correction for degradations increases the quantification accuracy, with PVE compensation playing a major role in the SUR quantification. The proposed methodology allows us to reach similar SUR values for different SPECT systems, thereby allowing a reliable standardisation in multicentric studies. (orig.)

  6. Quantification of dopaminergic neurotransmission SPECT studies with {sup 123}I-labelled radioligands. A comparison between different imaging systems and data acquisition protocols using Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Crespo, Cristina; Aguiar, Pablo [Universitat de Barcelona - IDIBAPS, Unitat de Biofisica i Bioenginyeria, Departament de Ciencies Fisiologiques I, Facultat de Medicina, Barcelona (Spain); Gallego, Judith [Universitat Politecnica de Catalunya, Institut de Tecniques Energetiques, Barcelona (Spain); Institut de Bioenginyeria de Catalunya, Barcelona (Spain); Cot, Albert [Universitat de Barcelona - IDIBAPS, Unitat de Biofisica i Bioenginyeria, Departament de Ciencies Fisiologiques I, Facultat de Medicina, Barcelona (Spain); Universitat Politecnica de Catalunya, Seccio d' Enginyeria Nuclear, Departament de Fisica i Enginyeria Nuclear, Barcelona (Spain); Falcon, Carles; Ros, Domenec [Universitat de Barcelona - IDIBAPS, Unitat de Biofisica i Bioenginyeria, Departament de Ciencies Fisiologiques I, Facultat de Medicina, Barcelona (Spain); CIBER en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona (Spain); Bullich, Santiago [Hospital del Mar, Center for Imaging in Psychiatry, CRC-MAR, Barcelona (Spain); Pareto, Deborah [CIBER en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona (Spain); PRBB, Institut d' Alta Tecnologia, Barcelona (Spain); Sempau, Josep [Universitat Politecnica de Catalunya, Institut de Tecniques Energetiques, Barcelona (Spain); CIBER en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona (Spain); Lomena, Francisco [IDIBAPS, Servei de Medicina Nuclear, Hospital Clinic, Barcelona (Spain); Calvino, Francisco [Universitat Politecnica de Catalunya, Institut de Tecniques Energetiques, Barcelona (Spain); Universitat Politecnica de Catalunya, Seccio d' Enginyeria Nuclear, Departament de Fisica i Enginyeria Nuclear, Barcelona (Spain); Pavia, Javier [CIBER en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona (Spain); IDIBAPS, Servei de Medicina Nuclear, Hospital Clinic, Barcelona (Spain)

    2008-07-15

    {sup 123}I-labelled radioligands are commonly used for single-photon emission computed tomography (SPECT) imaging of the dopaminergic system to study the dopamine transporter binding. The aim of this work was to compare the quantitative capabilities of two different SPECT systems through Monte Carlo (MC) simulation. The SimSET MC code was employed to generate simulated projections of a numerical phantom for two gamma cameras equipped with a parallel and a fan-beam collimator, respectively. A fully 3D iterative reconstruction algorithm was used to compensate for attenuation, the spatially variant point spread function (PSF) and scatter. A post-reconstruction partial volume effect (PVE) compensation was also developed. For both systems, the correction for all degradations and PVE compensation resulted in recovery factors of the theoretical specific uptake ratio (SUR) close to 100%. For a SUR value of 4, the recovered SUR for the parallel imaging system was 33% for a reconstruction without corrections (OSEM), 45% for a reconstruction with attenuation correction (OSEM-A), 56% for a 3D reconstruction with attenuation and PSF corrections (OSEM-AP), 68% for OSEM-AP with scatter correction (OSEM-APS) and 97% for OSEM-APS plus PVE compensation (OSEM-APSV). For the fan-beam imaging system, the recovered SUR was 41% without corrections, 55% for OSEM-A, 65% for OSEM-AP, 75% for OSEM-APS and 102% for OSEM-APSV. Our findings indicate that the correction for degradations increases the quantification accuracy, with PVE compensation playing a major role in the SUR quantification. The proposed methodology allows us to reach similar SUR values for different SPECT systems, thereby allowing a reliable standardisation in multicentric studies. (orig.)

  7. Current cardiac imaging techniques for detection of left ventricular mass

    Directory of Open Access Journals (Sweden)

    Celebi Aksuyek S

    2010-06-01

    Full Text Available Abstract Estimation of left ventricular (LV mass has both prognostic and therapeutic value independent of traditional risk factors. Unfortunately, LV mass evaluation has been underestimated in clinical practice. Assessment of LV mass can be performed by a number of imaging modalities. Despite inherent limitations, conventional echocardiography has fundamentally been established as most widely used diagnostic tool. 3-dimensional echocardiography (3DE is now feasible, fast and accurate for LV mass evaluation. 3DE is also superior to conventional echocardiography in terms of LV mass assessment, especially in patients with abnormal LV geometry. Cardiovascular magnetic resonance (CMR and cardiovascular computed tomography (CCT are currently performed for LV mass assessment and also do not depend on cardiac geometry and display 3-dimensional data, as well. Therefore, CMR is being increasingly employed and is at the present standard of reference in the clinical setting. Although each method demonstrates advantages over another, there are also disadvantages to receive attention. Diagnostic accuracy of methods will also be increased with the introduction of more advanced systems. It is also likely that in the coming years new and more accurate diagnostic tests will become available. In particular, CMR and CCT have been intersecting hot topic between cardiology and radiology clinics. Thus, good communication and collaboration between two specialties is required for selection of an appropriate test.

  8. Optimizing imaging in suspected appendicitis (OPTIMAP-study: A multicenter diagnostic accuracy study of MRI in patients with suspected acute appendicitis. Study Protocol

    Directory of Open Access Journals (Sweden)

    Bossuyt Patrick MM

    2010-10-01

    Full Text Available Abstract Background In patients with clinically suspected appendicitis, imaging is needed to substantiate the clinical diagnosis. Imaging accuracy of ultrasonography (US is suboptimal, while the most accurate technique (CT is associated with cancer related deaths through exposure to ionizing radiation. MRI is a potential replacement, without associated ionizing radiation and no need for contrast medium administration. If MRI is proven to be sufficiently accurate, it could be introduced in the diagnostic pathway of patients with suspected appendicitis, increasing diagnostic accuracy and improving clinical outcomes, without the risk of radiation induced cancer or iodinated contrast medium-related drawbacks. The multicenter OPTIMAP study was designed to estimate the diagnostic accuracy of MRI in patients with suspected acute appendicitis in the general population. Methods/Design Eligible for this study are consecutive patients presenting with clinically suspected appendicitis at the emergency department in six centers. All patients will undergo imaging according to the Dutch guideline for acute appendicitis: initial ultrasonography in all and subsequent CT whenever US does not confirm acute appendicitis. Then MRI is performed in all patients, but the results are not used for patient management. A final diagnosis assigned by an expert panel, based on all available information including 3-months follow-up, except MRI findings, is used as the reference standard in estimating accuracy. We will calculate the sensitivity, specificity, predictive values and inter-observer agreement of MRI, and aim to include 230 patients. Patient acceptance and total imaging costs will also be evaluated. Discussion If MRI is found to be sufficiently accurate, it could replace CT in some or all patients. This will limit or obviate the ionizing radiation exposure associated risk of cancer induction and contrast medium induced nephropathy with CT, preventing the burden and

  9. A method to implement the reservoir-wave hypothesis using phase-contrast magnetic resonance imaging

    OpenAIRE

    Gray, Robert D.M.; Parker, Kim H.; Quail, Michael A.; Taylor, Andrew M.; Biglino, Giovanni

    2016-01-01

    The reservoir-wave hypothesis states that the blood pressure waveform can be usefully divided into a “reservoir pressure” related to the global compliance and resistance of the arterial system, and an “excess pressure” that depends on local conditions. The formulation of the reservoir-wave hypothesis applied to the area waveform is shown, and the analysis is applied to area and velocity data from high-resolution phase-contrast cardiovascular magnetic resonance (CMR) imaging. A validation stud...

  10. Imaging

    International Nuclear Information System (INIS)

    Kellum, C.D.; Fisher, L.M.; Tegtmeyer, C.J.

    1987-01-01

    This paper examines the advantages of the use of excretory urography for diagnosis. According to the authors, excretory urography remains the basic radiologic examination of the urinary tract and is the foundation for the evaluation of suspected urologic disease. Despite development of the newer diagnostic modalities such as isotope scanning, ultrasonography, CT, and magnetic resonsance imaging (MRI), excretory urography has maintained a prominent role in ruorradiology. Some indications have been altered and will continue to change with the newer imaging modalities, but the initial evaluation of suspected urinary tract structural abnormalities; hematuria, pyuria, and calculus disease is best performed with excretory urography. The examination is relatively inexpensive and simple to perform, with few contraindictions. Excretory urography, when properly performed, can provide valuable information about the renal parenchyma, pelvicalyceal system, ureters, and urinary bladder

  11. A STRONG SECURITY PROTOCOL AGAINST FINGERPRINT DATABASE ATTACKS

    Directory of Open Access Journals (Sweden)

    U. Latha

    2013-08-01

    Full Text Available The Biometric data is subject to on-going changes and create a crucial problem in fingerprint database. To deal with this, a security protocol is proposed to protect the finger prints information from the prohibited users. Here, a security protocol is proposed to protect the finger prints information. The proposed system comprised of three phases namely, fingerprint reconstruction, feature extraction and development of trigon based security protocol. In fingerprint reconstruction, the different crack variance level finger prints images are reconstructed by the M-band Dual Tree Complex Wavelet Transform (DTCWT. After that features are extracted by binarization. A set of finger print images are utilized to evaluate the performance of security protocol and the result from this process guarantees the healthiness of the proposed trigon based security protocol. The implementation results show the effectiveness of proposed trigon based security protocol in protecting the finger print information and the achieved improvement in image reconstruction and the security process.

  12. Comparison of 3- and 20-Gradient Direction Diffusion-Weighted Imaging in a Clinical Subacute Cohort of Patients with Transient Ischemic Attack: Application of Standard Vendor Protocols for Lesion Detection and Final Infarct Size Projection

    Directory of Open Access Journals (Sweden)

    Inger Havsteen

    2017-12-01

    Full Text Available ObjectiveDiffusion tensor imaging may aid brain ischemia assessment but is more time consuming than conventional diffusion-weighted imaging (DWI. We compared 3-gradient direction DWI (3DWI and 20-gradient direction DWI (20DWI standard vendor protocols in a hospital-based prospective cohort of patients with transient ischemic attack (TIA for lesion detection, lesion brightness, predictability of persisting infarction, and final infarct size.MethodsWe performed 3T-magnetic resonance imaging including diffusion and T2-fluid attenuated inversion recovery (FLAIR within 72 h and 8 weeks after ictus. Qualitative lesion brightness was assessed by visual inspection. We measured lesion area and brightness with manual regions of interest and compared with homologous normal tissue.Results117 patients with clinical TIA showed 78 DWI lesions. 2 lesions showed only on 3DWI. No lesions were uniquely 20DWI positive. 3DWI was visually brightest for 34 lesions. 12 lesions were brightest on 20DWI. The median 3DWI lesion area was larger for lesions equally bright, or brightest on 20DWI [median (IQR 39 (18–95 versus 18 (10–34 mm2, P = 0.007]. 3DWI showed highest measured relative lesion signal intensity [median (IQR 0.77 (0.48–1.17 versus 0.58 (0.34–0.81, P = 0.0006]. 3DWI relative lesion signal intensity was not correlated to absolute signal intensity, but 20DWI performed less well for low-contrast lesions. 3DWI lesion size was an independent predictor of persistent infarction. 3-gradient direction apparent diffusion coefficient areas were closest to 8-week FLAIR infarct size.Conclusion3DWI detected more lesions and had higher relative lesion SI than 20DWI. 20DWI appeared blurred and did not add information.Clinical Trial Registrationhttp://www.clinicaltrials.gov. Unique Identifier NCT01531946.

  13. Rational design of biophysical imaging protocols to measure the level of intensity of massive delocalized infections under severe HIV-induced immunodeficiency: configuration of novel radioimmunoscintigraphy modalities with single-photon emission tomography (SPECT) and positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Nazarea, A.D.

    1996-01-01

    Severe immunosupression brought about by critical depletion of CD4 + -lymphocytes in individuals suffering from HIV infection leads inevitably to the onset of multiple-agent opportunistic infections (ARC: the AIDS-related complex). Such opportunistic infections eventually become heterogeneously delocalized (disseminated) and an idea f their variety and number can be gleaned from the listing under clinical category C of the 1993 CDC Revised Classification System for HIV infections. This causes widespread oxygen free radical (principally superoxide and hydroxyl free radical) burst due to the up-switching of the hexose monophosphate (HMP) shunt as a result of the generalized activation, by the massive infection load, of NADPH oxidase, a constitutive enzyme that is present in the cell membranes of all granulocytes and mononuclear phagocytic cells. However the very short (reactive) lifetimes of superoxide and hydroxyl free radicals in the cellular milieu preclude their use as a convenient in vivo biomarkers if the level of phagocytosis (or HMP up-switching) were to be utilized as a correlative measure of the level of intensity of delocalized infections in ARC in any non-invasive whole-body imaging protocol. In the present contribution, we report a rational schema for a molecularly specific an self-consistent correlative measure of the intensity of multiple-agent, delocalized infections arising from severe HIV-induced immunodeficiency. The schema is based on the quantitative parametrization of the level of on-going degranulation activity of neutrophils in the granulocyte population. The rationally designed modalities rest on specificity inherent in radioimmunoscintigraphy, in particular on the ligand of radionuclide-tagged antibodies to the neutrophil proteinases HLE (human leukocytic elastase: EC.3.4.21.37) and cat G (cathepsin G: EC.3.4.21.20). In this work, these molecular probes are specifically configured to lend themselves as convenient in vivo biomarkers both in

  14. The DD genotype of the angiotensin converting enzyme