Introduction: Native-MR angiography (N-MRA) is considered an imaging alternative to contrast enhanced MR angiography (CE-MRA) for patients with renal insufficiency. Lower intraluminal contrast in N-MRA often leads to failure of the segmentation process in commercial algorithms. This study introduces an in-house 3D model-based segmentation approach used to compare both sequences by automatic 3D lumen segmentation, allowing for evaluation of differences of aortic lumen diameters as well as differences in length comparing both acquisition techniques at every possible location.
Methods And Materials: Sixteen healthy volunteers underwent 1.5-T-MR Angiography (MRA). For each volunteer, two different MR sequences were performed, CE-MRA: gradient echo Turbo FLASH sequence and N-MRA: respiratory-and-cardiac-gated, T2-weighted 3D SSFP. Datasets were segmented using a 3D model-based ellipse-fitting approach with a single seed point placed manually above the celiac trunk. The segmented volumes were manually cropped from left subclavian artery to celiac trunk to avoid error due to side branches. Diameters, volumes and centerline length were computed for intraindividual comparison. For statistical analysis the Wilcoxon-Signed-Ranked-Test was used.
Results: Average centerline length obtained based on N-MRA was 239.0±23.4 mm compared to 238.6±23.5 mm for CE-MRA without significant difference (P=0.877). Average maximum diameter obtained based on N-MRA was 25.7±3.3 mm compared to 24.1±3.2 mm for CE-MRA (P<0.001). In agreement with the difference in diameters, volumes obtained based on N-MRA (100.1±35.4 cm(3)) were consistently and significantly larger compared to CE-MRA (89.2±30.0 cm(3)) (P<0.001).
Conclusions: 3D morphometry shows highly similar centerline lengths for N-MRA and CE-MRA, but systematically higher diameters and volumes for N-MRA.
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http://dx.doi.org/10.3978/j.issn.2223-3652.2013.10.06 | DOI Listing |
Vet Res Commun
January 2025
Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta N 36 Km 601, Río Cuarto City, 5800, Córdoba, Argentina.
Post-weaning diarrhea (PWD) is a major concern for pig producers, as stress and early weaning increase susceptibility to enteropathogens like enterotoxigenic Escherichia coli (ETEC) and Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium).
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January 2025
Department of Ultrasound, The First Medical Center, Chinese PLA General Hospital, No. 28 Fuxing Road, Haidian District, Beijing, 100853, China.
Objective: To compare the clinical outcomes of patients with unifocal paratracheal papillary thyroid microcarcinoma (PTMC) after thermal ablation (TA) vs. partial thyroidectomy (PT).
Materials And Methods: This retrospective multicenter study included 436 patients with unifocal, clinical N0 paratracheal PTMC who underwent TA (210 patients) or PT (236 patients) between June 2014 and December 2020.
J Phys Chem Lett
January 2025
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
Electrochemical nitrogen conversion for ammonia (NH) synthesis, driven by renewable electricity, offers a sustainable alternative to the traditional Haber-Bosch process. However, this conversion process remains limited by a low Faradaic efficiency (FE) and NH yield. Although transition metals have been widely studied as catalysts for NH synthesis through effective electron donation/back-donation mechanisms, there are challenges in electrochemical environments, including competitive hydrogen evolution reaction (HER) and catalyst stability issues.
View Article and Find Full Text PDFUrologia
January 2025
Department of Urology and Renal Transplantation, Sanjay Gandhi Postgraduate Institute of Medical Sciences Lucknow, Lucknow, Uttar Pradesh, India.
Introduction: Pseudotumors are benign lesions which may mimic like a malignant tumor on conventional imaging. They are formed in kidneys which are scarred and deformed by chronic pyelonephritis, glomerulonephritis, trauma or infarction. There is a diagnostic dilemma in most of the cases as to differentiate RCC and pseudotumors.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Neurosurgery, University Hospital Tübingen, Tübingen, Germany.
To compare 1D (linear) tumor volume calculations and classification systems with 3D-segmented volumetric analysis (SVA), focusing specifically on their effectiveness in the evaluation and management of NF2-associated vestibular schwannomas (VS). VS were clinically followed every 6 months with cranial, thin-sliced (< 3 mm) MRI. We retrospectively reviewed and used T1-weighted post-contrast enhanced (gadolinium) images for both SVA and linear measurements.
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