Ultrafast Protocol Research Articles

Performance of an ultra-fast deep-learning accelerated MRI screening protocol for prostate cancer compared to a standard multiparametric protocol

ObjectivesTo establish and evaluate an ultra-fast MRI screening protocol for prostate cancer (PCa) in comparison to the standard multiparametric (mp) protocol, reducing scan time and maintaining adequate diagnostic performance.Materials and methodsThis prospective single-center study included consecutive biopsy-naïve patients with suspected PCa between December 2022 and March 2023. A PI-RADSv2.1 conform mpMRI protocol was acquired in a 3 T scanner (scan time: 25 min 45 sec). In addition, two deep-learning (DL) accelerated sequences (T2- and diffusion-weighted) were acquired, serving as a screening protocol (scan time: 3 min 28 sec). Two readers evaluated image quality and the probability of PCa regarding PI-RADSv2.1 scores in two sessions. The diagnostic performance of the screening protocol with mpMRI serving as the reference standard was derived. Inter- and intra-reader agreements were evaluated using weighted kappa statistics.ResultsWe included 77 patients with 97 lesions (mean age: 66 years; SD: 7.7). Diagnostic performance of the screening protocol was excellent with a sensitivity and specificity of 100%/100% and 89%/98% (cut-off ≥ PI-RADS 4) for reader 1 (R1) and reader 2 (R2), respectively. Mean image quality was 3.96 (R1) and 4.35 (R2) for the standard protocol vs. 4.74 and 4.57 for the screening protocol (p < 0.05). Inter-reader agreement was moderate (κ: 0.55) for the screening protocol and substantial (κ: 0.61) for the multiparametric protocol.ConclusionThe ultra-fast screening protocol showed similar diagnostic performance and better imaging quality compared to the mpMRI in under 15% of scan time, improving efficacy and enabling the implementation of screening protocols in clinical routine.Clinical relevance statementThe ultra-fast protocol enables examinations without contrast administration, drastically reducing scan time to 3.5 min with similar diagnostic performance and better imaging quality. This facilitates patient-friendly, efficient examinations and addresses the conflict of increasing demand for examinations at currently exhausted capacities.Key PointsTime-consuming MRI protocols are in conflict with an expected increase in examinations required for prostate cancer screening.An ultra-fast MRI protocol shows similar performance and better image quality compared to the standard protocol.Deep-learning acceleration facilitates efficient and patient-friendly examinations, thus improving prostate cancer screening capacity.Graphical

Validation and Feasibility of Ultrafast Cervical Spine MRI Using a Deep Learning-Assisted 3D Iterative Image Enhancement System.

This study aimed to evaluate the feasibility of ultrafast (2 min) cervical spine MRI protocol using a deep learning-assisted 3D iterative image enhancement (DL-3DIIE) system, compared to a conventional MRI protocol (6 min 14s). Fifty-one patients were recruited and underwent cervical spine MRI using conventional and ultrafast protocols. A DL-3DIIE system was applied to the ultrafast protocol to compensate for the spatial resolution and signal-to-noise ratio (SNR) of images. Two radiologists independently assessed and graded the quality of images from the dimensions of artifacts, boundary sharpness, visibility of lesions and overall image quality. We recorded the presence or absence of different pathologies. Moreover, we examined the interchangeability of the two protocols by computing the 95% confidence interval of the individual equivalence index, and also evaluated the inter-protocol intra-observer agreement using Cohen's weighted kappa. Ultrafast-DL-3DIIE images were significantly better than conventional ones for artifacts and equivalent for other qualitative features. The number of cases with different kinds of pathologies was indistinguishable based on the MR images from ultrafast-DL-3DIIE and conventional protocols. With the exception of disc degeneration, the 95% confidence interval for the individual equivalence index across all variables did not surpass 5%, suggesting that the two protocols are interchangeable. The kappa values of these evaluations by the two radiologists ranged from 0.65 to 0.88, indicating good-to-excellent agreement. The DL-3DIIE system enables 67% spine MRI scan time reduction while obtaining at least equivalent image quality and diagnostic results compared to the conventional protocol, suggesting its potential for clinical utility.

Triage of Patients With Acute Stroke for Endovascular Therapy: Point-Moving Toward MRI-Based Acute Stroke Triage With Ultrafast Protocols.

Triage of Patients With Acute Stroke for Endovascular Therapy: Point-Moving Toward MRI-Based Acute Stroke Triage With Ultrafast Protocols.

Prime number factorization with light beams carrying orbital angular momentum

We point out a link between orbital angular momentum (OAM) carrying light beams and number theory. The established link makes it possible to formulate and implement a simple and ultrafast protocol for prime number factorization by employing OAM endowed beams that are modulated by a prime number sieve. We are able to differentiate factors from non-factors of a number by simply measuring the on-axis intensity of light in the rear focal plane of a thin lens focusing on a source beam. The proposed protocol solely relies on the periodicity of the OAM phase distribution, and hence, it is applicable to fully as well as partially coherent fields of any frequency and physical nature—from optical or x-ray to matter waves—endowed with OAM. Our experimental results are in excellent agreement with our theory. We anticipate that our protocol will trigger new developments in optical cryptography and information processing with OAM beams.

The effectiveness of an ultrafast breast MRI protocol in the differentiation of benign and malignant breast lesions

To evaluate the effectiveness of an ultrafast breast magnetic resonance imaging (MRI) protocol in differentiating benign and malignant breast lesions. Fifty-four patients with Breast Imaging Reporting and Data System (BI-RADS) 4 or 5 lesions were recruited between July 2020 to May 2021. A standard breast MRI was performed with the inclusion of the ultrafast protocol between the unenhanced sequence and the first contrast-enhanced sequence. Three radiologists performed image interpretation in consensus. Ultrafast kinetic parameters analysed included the maximum slope (MS), time to enhancement (TTE), and arteriovenous index (AVI). These parameters were compared using receiver operating characteristics with p-values of <0.05 considered to indicate statistical significance. Eighty-three histopathological proven lesions from 54 patients (mean age 53.87 years, SD 12.34, range 26-78 years) were analysed. Forty-one per cent (n=34) were benign and 59% (n=49) were malignant. All malignant and 38.2% (n=13) benign lesions were visualised on the ultrafast protocol. Of the malignant lesions, 77.6% (n=53) were invasive ductal carcinoma (IDC) and 18.4% (n=9) were ductal carcinoma in situ (DCIS). The MS for malignant lesions (13.27%/s) were significantly larger than for benign (5.45%/s; p<0.0001). No significant differences were seen for TTE and AVI. The area under the ROC curve (AUC) for the MS, TTE, and AVI were 0.836, 0.647, and 0.684, respectively. Different types of invasive carcinoma had similar MS and TTE. The MS of high-grade DCIS was also similar to that of IDC. Lower MS values were observed for low-grade (5.3%/s) compared to high-grade DCIS (14.8%/s) but the results were not significant statistically. The ultrafast protocol showed potential to discriminate between malignant and benign breast lesions with high accuracy using MS.

Ultrafast MRI using deep learning echoplanar imaging for a comprehensive assessment of acute ischemic stroke.

Acute ischemic stroke (AIS) is an emergency requiring both fast and informative MR sequences. We aimed to assess the performance of an artificial intelligence-enhanced ultrafast (UF) protocol, compared to the reference protocol, in the AIS management. We included patients admitted in the emergency department for suspected AIS. Each patient underwent a 3-T MR protocol, including reference acquisitions of T2-FLAIR, DWI, and SWI (duration: 7min 54s) and their accelerated multishot EPI counterparts for T2-FLAIR and T2*, complemented by a single-shot EPI DWI (duration: 1min 54s). Two blinded neuroradiologists reviewed each dataset, assessing DWI (detection, location, number of acute lesions), FLAIR (vascular hyperintensities, visibility of acute lesions), and SWI/T2* (hemorrhagic transformation, thrombus). We compared the agreement between the diagnoses obtained with both protocols using kappa coefficients. A total of 173 patients were included consecutively, of whom 80 with an AIS in DWI. We found an almost perfect agreement between the UF and reference protocols regarding the detection, distribution, number of AIS in DWI (κ = 0.98, 0.98, and 0.87 respectively), the presence of vascular hyperintensities, and the presence of a parenchymal hyperintensity in the AIS region in FLAIR (κ = 0.93 and 0.89 respectively). Agreement was substantial in T2*/SWI for thrombus detection, and fair for hemorrhagic transformation detection (κ = 0.64 and 0.38 respectively). Differential diagnoses were similarly detected by both protocols (κ = 1). Our AI-enhanced ultrafast MRI protocol allowed an effective detection and characterization of both AIS and differential diagnoses in less than 2min. • The AI-enhanced ultrafast MRI protocol allowed an effective detection of acute stroke. • Characterization of stroke features with the UF protocol was equivalent to the reference sequences. • Differential diagnoses were detected similarly by the UF and reference protocols.

ULTRAFAST WARMING PROTOCOL DEMONSTRATES SIMILAR OUTCOMES AND SIGNIFICANTLY DECREASES EMBRYOLOGY WORKLOAD COMPARED TO STANDARD WARMING PROTOCOLS, A RANDOMIZED CONTROL TRIAL WITH EUPLOID BLASTOCYSTS

Procedures within the IVF lab have become more complex and time-consuming resulting in embryologist fatigue. One of these procedures is embryo warming. Embryo warming requires 14 minutes of embryology bench time due to the movement of the embryo through TS (thawing solution), DS (dilute solution), and WS (washing solution). Therefore, we have modified the standard warming technique to merely moving the embryo to TS solution for 1 min and then immediately to culture media. This method eliminates the need for DS and WS steps and decreases the overall time to complete the warming process. It is the objective of this study to compare outcomes of embryos warmed with the standard protocol (14 minutes) versus embryos warmed with the ultrafast protocol (1 min).

Ultrafast lumbar spine MRI protocol using deep learning-based reconstruction: diagnostic equivalence to a conventional protocol.

To evaluate the diagnostic equivalency between an ultrafast (1min 53s) lumbar MRI protocol using deep learning-based reconstruction and a conventional lumbar MRI protocol (12min 31s). This study included 58 patients who underwent lumbar MRI using both conventional and ultrafast protocols, including sagittal T1-weighted, T2-weighted, short-TI inversion recovery, and axial T2-weighted sequences. Compared with the conventional protocol, the ultrafast protocol shortened the acquisition time to approximately one-sixth. To compensate for the decreased signal-to-noise ratio caused by the acceleration, deep learning-based reconstruction was applied. Three neuroradiologists graded degenerative changes and analyzed for presence of other pathologies. For the grading of degenerative changes, interprotocol intrareader agreement was assessed using kappa statics. Interchangeability between the two protocols was also tested by calculating the individual equivalence index between the intraprotocol interreader agreement and interprotocol interreader agreement. For the detection of other pathologies, interprotocol intrareader agreement was assessed. For the grading of degenerative changes, the kappa values for interprotocol intrareader agreement of all three readers ranged from 0.707 to 0.804, indicating substantial to almost perfect agreement. Except for foraminal stenosis and disc contour on axial images, the 95% confidence interval of the individual equivalence index was < 5%, indicating the two protocols were interchangeable. For the detection of other pathologies, the interprotocol intrareader agreement rates were > 98% for each individual pathology. Our proposed ultrafast lumbar spine MRI protocol provided almost equivalent diagnostic results to that of the conventional protocol, except for some degenerative changes.

Ultrafast cervcial spine MRI protocol using deep learning-based reconstruction: Diagnostic equivalence to a conventional protocol

PurposeA major drawback of magnetic resonance imaging (MRI) is its limited imaging speed. This study proposed an ultrafast cervical spine MRI protocol (2 min 57 s) using deep learning-based reconstruction (DLR) and compared the diagnostic results to those of conventional MRI protocols (12 min 54 s). MethodsFifty patients who underwent cervical spine MRI using both conventional and ultrafast protocols, including sagittal T1-weighted, T2-weighted, short-TI inversion recovery, and axial T2*-weighted imaging were included in this study. The ultrafast protocol shortened the acquisition time to approximately-one-fourth of that of the conventional protocol by reducing the phase matrix, oversampling rate, and number of excitations, and by applying compressed sensing. To compensate for the decreased signal-to-noise ratio caused by acceleration, noise reduction using DLR was performed. For image interpretation, three neuroradiologists graded or classified degenerative changes, including central canal stenosis, foraminal stenosis, endplate degeneration, disc degeneration, and disc hernia. The presence of other pathologies was also recorded. Given the absence of a reference standard, we tested the interchangeability of the two protocols by calculating the 95% confidence interval (CI) of the individual equivalence index. We also assessed the inter-protocol intra-reader agreement using kappa statistics. ResultsExcept for endplate degeneration, the 95 % CI of the individual equivalence index for all variables did not exceed 5 %, indicating interchangeability between the two protocols. The kappa values ranged from 0.600 to 0.977, indicating substantial to almost perfect agreement. ConclusionsThe proposed ultrafast MRI protocol yielded almost equivalent diagnostic results compared as the conventional protocol.

Ultrafast Brain Magnetic Resonance Imaging in Acute Neurological Emergencies: Diagnostic Accuracy and Impact on Patient Management.

The aim of this study was to investigate diagnostic accuracy and impact on patient management of an ultrafast (4:33 minutes/5 sequences) brain magnetic resonance imaging (MRI) protocol for the detection of intracranial pathologies in acute neurological emergencies. Four hundred forty-nine consecutive emergency patients with acute nontraumatic neurological symptoms were evaluated for this institutional review board-approved prospective single-center trial. Sixty patients (30 female, 30 male; mean age, 61 years) with negative head CT were included and underwent emergency brain MRI at 3 T subsequent to CT. MRI included the ultrafast protocol (ultrafast-MRI; sag T1 GRE, ax T2 TSE, ax T2 TSE Flair, ax T2* EPI-GRE, ax DWI SS-EPI; TA, 5 minutes) and an equivalent standard-length protocol (TA, 15 minutes) as reference standard. Two blinded board-certified neuroradiologists independently analyzed the MRI with regard to image quality (1, nondiagnostic; 2, substantial artifacts; 3, satisfactory; 4, minor artifacts; 5, no artifacts) and intracranial pathologies. Sensitivity and specificity for the detection of intracranial pathologies were calculated accordingly. Ninety-three additional intracranial lesions (acute ischemia, n = 21; intracranial hemorrhage/microbleeds, n = 27; edema, n = 2; white matter lesion, n = 38; chronic infarction, n = 3; others, n = 2) were detected by ultrafast-MRI, whereas 101 additional intracranial lesions were detected by the standard-length protocol (acute ischemia, n = 24; intracranial hemorrhage/microbleeds, n = 32; edema, n = 2; white matter lesion, n = 38; chronic infarction, n = 3; others, n = 2). Image quality was equivalent to the standard-length protocol. Ultrafast-MRI demonstrated high diagnostic accuracy (sensitivity, 0.939 [0.881-0.972]; specificity, 1.000 [0.895-1.000]) for the detection of intracranial pathologies. MRI led to a change in patient management in 10% compared with the initial CT. Ultrafast-MRI enables time-optimized diagnostic workup in acute neurological emergencies at high sensitivity and specificity compared with a standard-length protocol, with direct impact on patient management. Ultrafast MRI protocols are a powerful tool in the emergency setting and may be implemented on various scanner types based on the optimization of individual acquisition parameters.

FLASH: ultra-fast protocol to identify RNA-protein interactions in cells.

Determination of the in vivo binding sites of RNA-binding proteins (RBPs) is paramount to understanding their function and how they affect different aspects of gene regulation. With hundreds of RNA-binding proteins identified in human cells, a flexible, high-resolution, high-throughput, highly multiplexible and radioactivity-free method to determine their binding sites has not been described to date. Here we report FLASH (Fast Ligation of RNA after some sort of Affinity Purification for High-throughput Sequencing), which uses a special adapter design and an optimized protocol to determine protein–RNA interactions in living cells. The entire FLASH protocol, starting from cells on plates to a sequencing library, takes 1.5 days. We demonstrate the flexibility, speed and versatility of FLASH by using it to determine RNA targets of both tagged and endogenously expressed proteins under diverse conditions in vivo.

Magnetresonanztomographie des Gehirns bei Säuglingen und Kleinkindern

Magnetic resonance imaging (MRI) is increasingly being used for infants and small children due to rapid sequence protocols, broader scanner availability and good monitoring possibilities. The sequence protocol should always be adapted to the individual clinical needs of the infant or toddler. For some clinical indications, such as control of ventricular width in children with shunted hydrocephalus, ultrafast protocols can be used with ascanning time of just afew minutes. For more complex clinical questions, more extensive sequence protocols are warranted. Particularly for neonates and using a rapid investigation protocol, MRI examinations can very often be performed without sedation. The necessity of using gadolinium-based contrast agents has to be critically deliberated in infants and neonates and has to be exactly tailored to the clinical needs. In many cases MRI examinations of the brain in infants and neonates do not require gadolinium-based contrast agents.

Ultrafast variational simulation of nontrivial quantum states with long-range interactions

State preparation protocols ideally require as minimal operations as possible, in order to be implemented in near-term, potentially noisy quantum devices. Motivated by long range interactions (LRIs) intrinsic to many present-day experimental platforms (trapped ions, Rydberg atom arrays, etc.), we investigate the efficacy of variationally simulating non-trivial quantum states using the Variational Quantum-Classical Simulation (VQCS) protocol explored recently in [SciPost Phys. 6, 029 (2019)], in the presence of LRIs. We show that this approach leads to extremely efficient state preparation: for example, Greene-Horne-Zeilinger (GHZ) states can be prepared with O(1) iterations of the protocol, and a quantum critical point of the long range transverse field Ising model (TFIM) can be prepared with > 99% fidelity on a 100 qubit system with only one iteration. Furthermore, we show that VQCS with LRIs is a promising route for exploring generic points in the phase diagram of the long-range TFIM. Our approach thus provides concrete, ultrafast protocols for quantum simulators equipped with long range interactions.

Immediate extubation after heart transplantation in a child by remifentanil-based ultra-fast anesthesia

Rationale:Ventilator-associated complications comprise important fatal aetiologies during heart transplantation. Ultra-fast anesthesia might provide the most effective measure to prevent this type of complication. Immediate extubation after heart transplantation (IEAHT) has recently been reported in adult patients. However, IEAHT in children is much more challenging due to limitations in anesthesia protocols. Recently, we managed to perform an ultra-fast anesthesia protocol combined with IEAHT during a heart transplant operation in a child, who had an excellent postoperative outcome.Patient concerns:A 13-year-old girl had been diagnosed with dilated cardiomyopathy 5 years before this case, due to intractable dyspnoea and cough. She received multiple medical treatments after diagnosis, with minimal effects. Physical examination findings included a bulge in her left chest and pitting edema over both legs. Moist rales could be heard in the lung. Echocardiography revealed very large heart chambers, with an ejection fraction of 17%.Diagnosis:The patient was diagnosed with dilated cardiomyopathy and scheduled to undergo an emergent operation for heart transplantation.Interventions:The patient underwent an ultra-fast anesthesia protocol and ultra-fast reversal during heart transplantation. General anesthesia was induced with etomidate, fentanyl, and vecuronium; it was then maintained with remifentanil-based total intravenous anesthesia.Outcomes:Immediately after the end of the operation, the patient was brought to consciousness with stable breathing and haemodynamics. The patient was successfully extubated on the operating table and transferred to the intensive care unit with spontaneous breathing, without postoperative mechanical ventilation. The recovery period was uneventful and the patient was discharged 1 month later without complications.Lessons:Our experience, in this case, revealed that IEAHT in children is achievable if the ultra-fast protocol is performed properly and carefully, in order to prevent ventilator-associated complications.

Clinical feasibility of 1-min ultrafast brain MRI compared with routine brain MRI using synthetic MRI: a single center pilot study.

Ultrafast brain MRI is required for uncooperative patients and time-critical diseases such as stroke because it reduces scan times and motion artifacts. This study investigated the clinical feasibility of a 1-min ultrafast brain MRI protocol for detecting intracranial abnormalities in restless and uncooperative patients. We retrospectively reviewed the records of 25 patients who underwent a 1-min ultrafast MRI protocol using T1-weighted image, T2-weighted image, echo-planar fluid-attenuated inversion recovery, diffusion-weighted image, and T2*-weighted image between March 2017 and May 2017. Simple methods were applied for ultrafast MRI protocol to reduce scan time as follows: parallel imaging techniques, multiband technique on diffusion sequence, and echo-planar fluid-attenuated inversion recovery. The images were compared with the routine brain MRI protocol using synthetic MRI, and quality was assessed by two independent readers. The Wilcoxon signed-rank test was used to compare the readers' ratings of the routine MRI protocol and ultrafast MRI protocol images. Using a four-point assessment scale, overall image quality and anatomical delineation of ultrafast brain MRI images were lower than those of routine brain MRI images. However, the ultrafast protocol demonstrated sufficient overall image quality and anatomical delineation with an assessment rating greater than two points. The ultrafast protocol had fewer artifacts than the routine protocol using synthetic MRI. Although the overall image quality and anatomical delineation of the 1-min ultrafast MRI were inferior to those of the routine brain MRI protocol, the ultrafast protocol showed at least sufficient image quality. Therefore, this protocol may be an option in specific clinical situations involving non-cooperative, restless, or pediatric patients, or patients with time-critical disease such as stroke. Further study is required to validate our findings.

Abbreviated breast magnetic resonance protocol: Value of high-resolution temporal dynamic sequence to improve lesion characterization

PurposeTo evaluate the added value of ULTRAFAST-MR sequence to an abbreviated FAST protocol in comparison with FULL protocol to distinguish benign from malignant lesions in a population of women, regardless of breast MR imaging indication. Materials and methodsFrom March 10th to September 22th, 2014, we retrospectively included a total of 70 consecutive patients with 106 histologically proven lesions (58 malignant and 48 benign) who underwent breast MR imaging for preoperative breast staging (n=38), high-risk screening (n=7), problem solving (n=18), and nipple discharge (n=4) with 12 time resolved imaging of contrast kinetics (TRICKS) acquisitions during contrast inflow interleaved in a regular high-resolution dynamic MRI protocol (FULL protocol). Two readers scored MR exams as either positive or negative and described significant lesions according to Bi-RADS lexicon with a TRICKS images (ULTRAFAST), an abbreviated protocol (FAST) and all images (FULL protocol). Sensitivity, specificity, positive and negative predictive values, and accuracy were calculated for each protocol and compared with McNemar’s test. ResultsFor all readers, the combined FAST–ULTRAFAST protocol significantly improved the reading with a specificity of 83.3% and 70.8% in comparison with FAST protocol or FULL protocol, respectively, without change in sensitivity. By adding ULTRAFAST protocol to FAST protocol, readers 1 and 2 were able to correctly change the diagnosis in 22.9% (11/48) and 10.4% (5/48) of benign lesions, without missing any malignancy, respectively. Both interpretation and image acquisition times for combined FAST-ULTRAFAST protocol and FAST protocol were shorter compared to FULL protocol (p<0.001). ConclusionCompared to FULL protocol, adding ULTRAFAST to FAST protocol improves specificity, mainly in correctly reclassifying benign masses and reducing interpretation and acquisition time, without decreasing sensitivity.

QRT-PCR for enterovirus detection: Conversion to ultrafast protocols

Enterovirus group (EV) still causes significant morbidity with economic impact worldwide. Quantitative RT-PCR (qRT-PCR) technology offers many advantages over to conventional RT-PCR in terms of rapidity and specificity. The TaqMan hydrolysis probe technique and Syber Green I intercalating dye strategy are by then largely used. Several published protocols are applied routinely for EV detection in food and environmental analysis advanced in chemical strategies and thermal profiles, in order to reduce the response times. In this study an Ultra-Fast protocol to detect and quantify EV RNA genome was tested and the application prospective of the protocol was described and discussed. The assay effectiveness was evaluated comparing two different set of primers/probe, targeting a 5′UTR region of EV genome. Three different oligonucleotides concentration were tested: 200nM, 250nM and 300nM for TaqMan technique whereas 200nM, 300nM and 400nM were employed for Syber Green I chemistry. The results demonstrated the validity of this Ultra-Fast approach, compared to the Traditional and Fast protocols. The best performance was obtained using 200nM of proper oligonucleotides, in both of the chemical strategies tested. The response time of analysis was reduced at 50′ (probe) and 57′ (intercalating dye) per run, against the other longer protocols. The oligonucleotides features can affect the assay performance and should satisfy specific characteristics.

Comparison of the prognostic value of myocardial perfusion imaging using a CZT-SPECT camera with a conventional anger camera

BackgroundRecent studies have shown that myocardial perfusion imaging (MPI) in cadmium-zinc-telluride (CZT) cameras allow faster exams with less radiation dose but there are little data comparing its prognosis information with that of dedicated cardiac Na-I SPECT cameras ObjectiveThe objective of this study is to compare the prognostic value of MPI using an ultrafast protocol with low radiation dose in a CZT-SPECT and a traditional one. MethodsGroup 1 was submitted to a two-day MIBI protocol in a conventional camera, and group 2 was submitted to a 1-day MIBI protocol in CZT camera. MPI were classified as normal or abnormal, and perfusion scores were calculated. Propensity score matching methods were performed Results3554 patients were followed during 33±8 months. Groups 1 and 2 had similar distribution of age, gender, body mass index, risk factors, previous revascularization, and use of pharmacological stress. Group 1 had more abnormal scans, higher scores than group 2. Annualized hard events rate was higher in group 1 with normal scans but frequency of revascularization was similar to normal group 2. Patients with abnormal scans had similar event rates in both groups ConclusionNew protocol of MPI in CZT-SPECT showed similar prognostic results to those obtained in dedicated cardiac Na-I SPECT camera, with lower prevalence of hard events in patients with normal scan.

Ultrafast CMR to deliver high volume screening of an at risk thalassemia population in the developing world: preliminary results from the TIC-TOC study (Thailand and UK international collaboration in thalassaemia using an optimised ultrafast CMR protocol)

Ultrafast CMR to deliver high volume screening of an at risk thalassemia population in the developing world: preliminary results from the TIC-TOC study (Thailand and UK international collaboration in thalassaemia using an optimised ultrafast CMR protocol) Amna Abdel-Gadir, Yongkasem Vorasettakarnkij, Hataichanok Ngamkasem, Sabrina Nordin, Emmanuel O Ako, Monravee Tumkosit, Pranee Sutcharitchan, Peter Kellman, Stefan K Piechnik, Juliano L Fernandes, Mark Westwood, John Porter, John Malcolm Walker, James Moon

Ultra-fast formation control of high-order discrete-time multi-agent systems based on multi-step predictive mechanism

This paper deals with the ultra-fast formation control problem of high-order discrete-time multi-agent systems. Using the local neighbor-error knowledge, a novel ultra-fast protocol with multi-step predictive information and self-feedback term is proposed. The asymptotic convergence factor is improved by a power of q+1 compared to the routine protocol. To some extent, the ultra-fast algorithm overcomes the influence of communication topology to the convergence speed. Furthermore, some sufficient conditions are given herein. The ones decouple the design of the synchronizing gains from the detailed graph properties, and explicitly reveal how the agent dynamic and the communication graph jointly affect the ultra-fast formationability. Finally, some simulations are worked out to illustrate the effectiveness of our theoretical results.