Philips (Germany)

To compare the diagnostic quality of deep learning (DL) super-resolution reconstructed breath-hold (BH) and free-breathing (FB) single-shot (SSH) black-blood T2-weighted short tau inversion recovery (STIR) imaging with standard BH T2-STIR in cardiovascular magnetic resonance (CMR). In this prospective study, short-axis BH and FB SSH T2-STIR were added to a standard cardiomyopathy CMR protocol at 1.5T, and DL super-resolution reconstruction was performed. Two readers evaluated diagnostic quality and certainty using a five-point Likert scale. Presence of focal edema was assessed on T2-weighted sequences, including standard T2-STIR and T2 mapping (both used for reference clinical assessment) as well as SSH T2 STIR and DL-SSH T2-STIR. Friedman test and one-way ANOVA were performed. Eighty-one participants (mean age: 54 ±20 years; 50 men) were included. No difference was found in edema detection between reference assessment and DL-SSH T2-STIR (both 26%, (21/81 participants)). Scan time was reduced by 63% for BH and 86% for FB DL-SSH T2-STIR compared to standard T2-STIR (90± 6s vs. 35± 3s vs. 243± 16s; p<.0001). BH and FB DL-SSH T2-STIR achieved lower artifact burden (5 [IQR, 4-5] vs. 4 [IQR, 4-5] vs. 4 [IQR, 3-5]; p<.0001), superior image contrast and sharpness compared to standard T2-STIR, especially in non-cooperative or arrhythmic participants. BH and FB DL-SSH T2-STIR imaging provided higher diagnostic certainty than standard T2-STIR (5 [IQR, 5-5] vs. 5 [IQR, 5-5] vs. 4 [IQR, 4-5]; p<.0001). Edema visibility was superior in BH DL-SSH compared to BH-SSH and standard T2-STIR (5 [IQR, 4.8-5] vs. 4 [IQR, 3.3-5] vs. 4 [IQR, 3-4.8]; p<.0001). Inter-rater agreement was substantial to excellent in the rating of edema visibility (BH DL-SSH T2-STIR, κ: 0.73 [95% CI: 0.44-1.0]; BH SSH T2-STIR, κ: 0.79 [95% CI: 0.66-0.97]; standard T2-STIR, κ: 0.86 [95% CI: 0.71-1.0]). Slice level-analysis showed that BH DL-SSH T2-STIR consistently provided superior image quality in apical slices compared to BH SSH and standard T2-STIR (4 [IQR, 4-5] vs. 4 [IQR, 4-4] vs. 4 [IQR, 3-4]; p<.0001). DL-SSH imaging enabled ultrafast T2-STIR acquisition and robust edema assessment in routine clinical CMR.

Zusammenfassung Das Multiple Myelom (MM) ist die zweithäufigste hämatoonkologische Erkrankung und charakterisiert durch eine klonale Proliferation maligner Plasmazellen sowie eine Knochenmarksinfiltration. Der für die Diagnostik und Therapieinitiierung wichtige Knochenmarksinfiltrationsgrad wird mittels Punktion festgelegt. Während die MRT und CT als Standardmethoden zur bildgebenden Diagnostik fokaler Läsionen und Osteolysen gelten, stößt insbesondere die CT bei diffusen Infiltrationsmustern ohne Osteolysen an ihre Grenzen. Spektrale CT-Techniken bieten durch Materialdekomposition eine vielversprechende Alternative zur Erfassung einer Knochenmarksinfiltration. Es erfolgte eine systematische Literaturrecherche in der PubMed-Datenbank zu relevanten Stichworten in zwischen 01/2010 und 12/2024 publizierten Artikeln. Eingeschlossen wurden Originalstudien, die spektrale CT-Techniken hinsichtlich der Beurteilung einer Knochenmarksinfiltration evaluierten. Ausgeschlossen wurden Artikel mit anderem Fokus, z.B. Frakturdetektion. Es erfolgte eine qualitative Synthese der Studienergebnisse. Spektrale CT-Techniken können die Differenzierung zwischen gesundem und infiltriertem Knochenmark verbessern. Insbesondere die häufig angewendete virtuelle Calciumsuppression zeigt eine gute Sensitivität und Spezifität verglichen mit der Histologie, Serologie oder MRT. Auch für die Differenzierung verschiedener Knochenmarksinfiltrationsmuster, der Krankheitsaktivität und des Therapieansprechens bietet die Spektral-CT Potenzial. Einschränkungen liegen in der Sensitivität der Differenzierung einer moderaten Infiltration gegenüber rotem Knochenmark sowie geringen Kohortengrößen. Multizentrische Analysen verschiedener Gerätehersteller sind erforderlich, um den Stellenwert der spektralen CT im Vergleich zur MRT, den prädiktiven Nutzen von Spektral-CT-Biomarkern sowie die Rolle weniger untersuchter Materialdichtekarten und Texturmerkmale, als auch der Photon-Counting-CT zu validieren.

To evaluate the non-contrast-enhanced relaxation-enhanced angiography without contrast (REACT) sequence for the assessment of extrathoracic vessels in pediatric patients compared to contrast-enhanced (CE), multiphasic magnetic resonance angiography (MRA). In this prospective, single-center study, pediatric patients referred for clinically indicated contrast-enhanced MRI of various extrathoracic body regions underwent additional free-breathing REACT and multiphasic, free-breathing CE-MRA at 1.5 T (Philips Ingenia). REACT was acquired using Cartesian k-space order, except in the abdomen, where it was acquired using a radial stack of stars k-space sampling (REACT VANE). The acquisition time was recorded. Image quality (Likert scale 1-5, with 5 being the best) and vessel diameter were evaluated by two independent readers in four predefined vessels in each body region. Furthermore, a quantitative analysis of SNR and CNR was performed. 30 patients (age: 12.3 ± 4 years) successfully completed REACT and CE-MRA. The acquisition time for REACT was 2:49 ± 1:03 min, while abdominal REACT VANE required 4:51 ± 0:52 min. The CE-MRA acquisition time was 3:49 ± 1:03 min. The median image quality ratings were good to excellent (Likert scale 4-5) for both readers. No significant difference in the image quality ratings was found (p = 0.12 - 0.58). Interobserver agreement of image quality ratings of the two readers was moderate to substantial (Cohen's kappa REACT: 0.58, CE-MRA: 0.64). Vessel diameter measurements showed a strong correlation (r = 0.93) between REACT and CE-MRA with high intraclass correlation coefficients (REACT: 0.97, CE-MRA: 0.97). Quantitative analysis showed a higher venous SNR and higher arterial and venous CNR in REACT (p = 0.001-0.018). Given the good and comparable image quality, REACT can be useful in vascular imaging in children under free-breathing, while potentially eliminating the need for contrast agent injection. · MR angiography is widely used in pediatric imaging for vessel assessment.. · Contrast-enhanced MRA has limitations due to the use of gadolinium-based contrast agents.. · REACT is a novel contrast-free MRA technique performed during free breathing.. · REACT provides image quality comparable to contrast-enhanced free-breathing MRA.. · Spogis J, Tsiflikas I, Katemann C et al. Free-breathing non-contrast-enhanced flow-independent MR angiography using REACT: A prospective study for pediatric vessel assessment. Rofo 2026; 10.1055/a-2781-8861.

Reduced contrast media (CM) dose at elevated heart rates (HRs) poses a challenge for coronary artery disease (CAD) assessment. Using a dynamic phantom, we evaluated the performance of a vendor-specific coronary motion-compensated reconstruction (MCR) at various simulated HRs and reduced CM dose in low virtual monoenergetic images (VMIs) from coronary computed tomography angiography (CCTA). A clinical CCTA protocol was used to image a 5-mm artificial coronary artery, filled with 100% (400 Hounsfield units (HU)) and 50% CM dose, using a robotic arm for translation at six velocities (0-50mm/s, 10mm/s steps). Conventional images and VMIs (40-70keV, 10keV steps) were reconstructed without and with MCR. The study evaluated the MCR influence on motion area and contrast-to-noise ratio (CNR) of the resulting segmented arteries (motion area), with the static conventional reconstructed artery at 100% CM dose as the reference, and non-overlapping 95% confidence intervals with the reference indicating significant differences. At 50% CM dose, motion area increased significantly (up to 50%) at elevated velocities (≥ 30mm/s) without MCR, while no significant variations were observed with MCR. Additionally, without MCR, VMIs exhibited significant CNR decreases (up to 65%) at velocities ≥ 30mm/s. Only the combination of MCR and 40keV VMI achieved CNR comparable to the reference, regardless of HR. The combination of MCR with low VMIs enables 50% CM dose reduction, with similar motion area and CNR when compared to conventional CCTA with 100% CM dose. These parameter settings can potentially be used to optimize low CM dose CCTA at higher HRs.

REACT (Relaxation-Enhanced Angiography without ContrasT) is a reliable non-contrast magnetic resonance angiography for imaging of the thoracic aorta but remains time-consuming. This study evaluates acceleration of image acquisition using compressed sensing and parallel imaging (Compressed SENSE, CS) combined with deep learning-based image reconstruction (CS-AI). In this prospective single-center study, 40 volunteers underwent ECG- and navigator-triggered 3D REACT at 3T using CS acceleration factor 4 (CS4; reference standard) and 8 (CS8). CS8 data were reconstructed with standard and CS-AI methods (CS8-AI). Two radiologists measured aortic diameters, rated subjective image quality and performed pairwise comparisons. Additionally, objective image quality metrics were calculated. Median scan time was reduced by 44% (CS4: 8:41min; CS8/CS8-AI: 4:52min). All techniques showed excellent agreement in aortic diameter measurements (mean differences<0.2mm; P>0.999). CS8-AI demonstrated reduced mean absolute deviation from CS4 compared to CS8 (0.67 vs. 0.77mm; P=0.003), and measurement variance was 40-50% lower with CS8-AI than with CS8 (inter-/intrarater: P<0.001), and comparable to CS4. CS8 showed significantly lower subjective image quality scores than CS4 (3.70[3.33-4.00] vs. 4.25[3.90-4.50]; P<0.001), while CS8-AI showed comparable or higher scores (4.40[4.00-4.70]; P=0.076). Forced-choice comparisons favored CS4 over CS8 (90% vs. 2.5%; P<0.001), but no preference was observed between CS4 and CS8-AI (42.5% vs. 37.5%; P>0.999). Objective metrics predominantly confirmed the subjective results. Deep learning-based reconstruction enables the acquisition of REACT of the thoracic aorta in less than five minutes while preserving high image quality and maintaining excellent measurement reproducibility.

Foetal circulation undergoes complex changes in congenital heart disease (CHD) that are challenging to assess with foetal echocardiography. This study aimed to assess clinical feasibility and diagnostic value of 4D flow cardiovascular magnetic resonance (CMR) in foetal CHD. Pregnant women in advanced third trimester pregnancy with foetal CHD were prospectively recruited for foetal CMR between August 2021 and November 2024. CMR protocol included cine and 4D time-resolved PC acquisitions. 4D flow data were evaluated for additional diagnostic information beyond cine imaging. Postnatal examination reports were used to confirm CMR findings. Net flow was quantified in the ascending aorta, distal aortic arch, main pulmonary artery, ductus arteriosus, and descending aorta and normalized to combined ventricular output (CVO). Student's t-test and analysis of variance with Tukey post hoc test were applied. Among 77 participants, 4D flow was of diagnostic quality in 62 (81%) foetuses [11/62 (18%) without CHD, 51/62 (82%) with CHD]. Comparison of net flow distributions revealed significant differences between foetuses without CHD and those with hypoplastic left heart complex (HLHC), dextro-transposition of the great arteries, and coarctation of the aorta. CVO was higher in normal foetal circulation compared with CHD (6.4 ± 1.5 mL vs. 5.1 ± 1.9 mL, P = 0.049). 4D flow provided diagnostic findings beyond cine imaging in 26/51 (51%) foetuses with CHD (e.g. retrograde aortic perfusion in HLHC) that were confirmed postnatally. Foetal 4D flow CMR characterizes flow patterns and provides relevant diagnostic information beyond cine imaging for prenatal CHD assessment.

Herein we report the very first experiments which were conducted in an attempt to demonstrate the ability of low-field (LF), compact benchtop NMR spectrometers to provide spectral profiles of whole human biofluids, which took place in September–November 2014, and this paper represents a 10-year (decennial) anniversary of this work. LF 1H NMR analysis was performed on 2H2O-reconstituted lyophilizates of urine samples (pH 7.00) collected from untreated Niemann-Pick type C1 (NPC1) disease patients and their heterozygous carrier controls (n = 3 in each case). 1H NMR spectra were acquired on a 60 MHz Oxford Instruments Pulsar compact benchtop spectrometer with spectral filter widths of 5000 Hz, using 1000–1600 scans, and relaxation delays of 15 or 30 s. Further, 400 MHz spectra were also obtained on these samples. Following parameter optimisation, the benchtop system generated reasonable quality urinary 1H NMR profiles containing ca. 30 signals. Benchtop 1H NMR analysis confirmed the abnormal urinary metabolic signature of NPC1 disease, and also revealed a gastric permeability disorder in one patient (detection of upregulated urinary sucrose, verified by 400 MHz NMR analysis). Early LF NMR experiments also demonstrated that glucose was trackable in control urine samples pre-spiked with this metabolite. This paper continues with further developments made on LF NMR-based metabolomics technologies, which are systematically discussed for related investigations conducted since 2014. In conclusion, such ‘first-time’ bioanalytical information regarding spectral quality served to pave the way forward for benchtop NMR-based metabolomics investigations of biofluids, which could provide invaluable disease-engendered ‘snapshots’ of disturbances to metabolic pathways and activities, along with those of any co-linked or unlinked comorbidities.

Background: Material structures at the micrometer scale cause ultra-small-angle X-ray scattering, e.g., seen in lung tissue or plastic foams. In grating-based X-ray imaging, this causes a reduction of the fringe visibility, forming a dark-field signal. Polychromatic beam hardening also changes visibility, adding a false dark-field signal due to attenuation, even in homogeneous, non-scattering materials. Purpose: The objective of this study is to develop a fast, simple, and robust method to correct dark-field signals and bony structures present due to beam hardening on dark-field chest radiographs of study participants. Methods: The method is based on calibration measurements and image processing. Beam hardening by bones and soft tissue is modeled by aluminum and water, respectively, which have no microstructure and thus only generate an artificial dark-field signal. Look-up tables were then created for both. By using a weighted mean of these, forming a single look-up table, and using the attenuation images, the artificial dark-field signal and thus the bone structures present are reduced for study participants. Results: It was found that applying a correction using a weighted look-up table leads to a significant reduction of bone structures in the dark-field image. The weighting of the aluminum component has a substantial impact on the degree to which bone structures remain visible in the dark-field image. Furthermore, a large negative bias in the dark-field image, dependent on the aluminum weighting, was successfully corrected. Conclusions: The beam-hardening-induced signal in the dark-field images was successfully reduced using the method described. The choice of aluminum weighting to suppress rib structures, as well as the selection of bias correction, should be evaluated based on the specific clinical question.

<strong class="journal-contentHeaderColor">Abstract.</strong> While modern wind turbine blades utilize pultruded carbon fiber-reinforced polymer (CFRP) planks for structural integrity in spar caps, these materials can sustain damage from operational stresses, leading to potential failures if unaddressed. Traditional down-tower repairs result in significant costs related to dismantling and transportation, especially for offshore installations, emphasizing the need for efficient up-tower repair methods. The research utilizes a finite element model of an 81.6 m rotor blade designed for a 7 MW offshore turbine, subjected to aeroelastic simulations to evaluate load conditions during maintenance. The analysis focuses on a step-wise increased repair zone, assessing susceptibility to buckling, cyclic strains, and permissible wind speeds. Results indicate that while substantial repairs can endanger structural stability, turbulence-induced strain amplitudes are manageable. Recommendations include installing temporary pretensioning and buckling support structures to enhance safety during repairs. Various innovative support designs are proposed for installation from both inside and outside the blade, aimed at improving structural integrity during up-tower repairs.