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high resolution MRI

Yuan Luo, Parinaz Abiri, Shell Zhang, Chih-Chiang Chang, Amir H Kaboodrangi, Rongsong Li, Ashish K Sahib, Alex Bui, Rajesh Kumar, Mary Woo, Zhaoping Li, René R Sevag Packard, Yu-Chong Tai, Tzung K Hsiai
Introduction: Obesity is associated with an increased risk of nonalcoholic fatty liver disease (NAFLD). While Magnetic Resonance Imaging (MRI) is a non-invasive gold standard to detect fatty liver, we demonstrate a low-cost and portable electrical impedance tomography (EIT) approach with circumferential abdominal electrodes for liver conductivity measurements. Methods and Results: A finite element model (FEM) was established to simulate decremental liver conductivity in response to incremental liver lipid content...
2018: Theranostics
Sa Xiao, He Deng, Caohui Duan, Junshuai Xie, Huiting Zhang, Xianping Sun, Chaohui Ye, Xin Zhou
Dynamic hyperpolarized (HP)129 Xe MRI is able to visualize the process of lung ventilation, which potentially provides unique information about lung physiology and pathophysiology. However, the longitudinal magnetization of HP129 Xe is nonrenewable, making it difficult to achieve high image quality while maintaining high temporal-spatial resolution in the pulmonary dynamic MRI. In this paper, we propose a new accelerated dynamic HP129 Xe MRI scheme incorporating the low-rank, sparse and gas-inflow effects (L + S + G) constraints...
March 8, 2018: Journal of Magnetic Resonance
Davis C Woodworth, Langston T Holly, Emeran A Mayer, Noriko Salamon, Benjamin M Ellingson
BACKGROUND: Advanced cervical spondylosis (CS) can cause structural damage to the spinal cord resulting in long-term neurological impairment including neck pain and motor weakness. We hypothesized long-term structural reorganization within the brain in patients with CS. OBJECTIVE: To explore the associations between cortical thickness, subcortical volumes, neurological symptoms, and pain severity in CS patients with or without myelopathy and healthy controls (HCs)...
March 14, 2018: Neurosurgery
Mark O Wielpütz, Ho Yun Lee, Hisanobu Koyama, Takeshi Yoshikawa, Shinichiro Seki, Yuji Kishida, Yasuhiro Sakai, Hans-Ulrich Kauczor, Kazuro Sugimura, Yoshiharu Ohno
OBJECTIVE: Ultrashort TE (UTE) MRI has been shown to deliver high-resolution images comparable to CT images. Here we evaluate the potential of UTE-MRI for precise lung nodule characterization. SUBJECTS AND METHODS: Fifty-one patients (mean [± SD] age, 68.7 ± 10.8 years) with 119 nodules or masses (mean size, 17.4 ± 16.3 mm; range, 4-88 mm) prospectively underwent CT (1-mm slice thickness) and UTE-MRI (TE, 192 μs; 1 mm3 resolution). Two radiologists assessed nodule dimensions and morphologic features (i...
March 16, 2018: AJR. American Journal of Roentgenology
Sara Guerri, Daniele Mercatelli, Maria Pilar Aparisi Gómez, Alessandro Napoli, Giuseppe Battista, Giuseppe Guglielmi, Alberto Bazzocchi
Bone and muscle are two deeply interconnected organs and a strong relationship between them exists in their development and maintenance. The peak of both bone and muscle mass is achieved in early adulthood, followed by a progressive decline after the age of 40. The increase in life expectancy in developed countries resulted in an increase of degenerative diseases affecting the musculoskeletal system. Osteoporosis and sarcopenia represent a major cause of morbidity and mortality in the elderly population and are associated with a significant increase in healthcare costs...
February 2018: Quantitative Imaging in Medicine and Surgery
Galateia J Kazakia, Julio Carballido-Gamio, Andrew Lai, Lorenzo Nardo, Luca Facchetti, Courtney Pasco, Chiyuan A Zhang, Misung Han, Amanda Hutton Parrott, Phyllis Tien, Roland Krug
Background: There is evidence that human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) are independent risk factors for osteoporosis and fracture which is not solely explained by changes in bone mineral density. Thus, we hypothesized that the assessment of trabecular microstructure might play an important role for bone quality in this population and might explain the increased fracture risk. In this study, we have assessed bone microstructure in the proximal femur using high-resolution magnetic resonance imaging (MRI) as well as in the extremities using high resolution peripheral quantitative computed tomography (HR-pQCT) in HIV-infected men and healthy controls and compared these findings to those based on areal bone mineral density (aBMD) derived from dual X-ray absorptiometry (DXA) which is the standard clinical parameter for the diagnosis of osteoporosis...
February 2018: Quantitative Imaging in Medicine and Surgery
Andrew J Lawrence, Daniel J Tozer, Emmanuel A Stamatakis, Hugh S Markus
Objective: MRI measures of network integrity may be useful disease markers in cerebral small vessel disease (SVD). We compared the sensitivity and reproducibility of MRI derived structural and functional network measures in healthy controls and SVD subjects. Methods: Diffusion tractography and resting state fMRI were used to create connectivity matrices from 26 subjects with symptomatic MRI confirmed lacunar stroke and 19 controls. Matrices were constructed at multiple scales based on a multi-resolution cortical atlas and at multiple thresholds for the matrix density...
2018: NeuroImage: Clinical
Ali S Haider, Christopher S Graffeo, Avital Perry, Lucas P Carlstrom, Terry C Burns
Insular gliomas were previously considered inoperable lesions and were typically treated via biopsy, chemotherapy and/or radiation, if not observation alone. Stereotactic biopsies of low grade insular gliomas can underestimate tumor grade or fail to establish malignancy. Moreover, the survival advantages of maximal safe resection for insular lesions are increasingly being recognized. As such, early surgical resection is increasingly being performed. As with most lesions, a differential diagnosis exists for apparent insular gliomas, with definitive diagnosis generally obtained upon resection...
January 11, 2018: Curēus
Arata Abe, Tetsuro Sekine, Yuki Sakamoto, Mina Harada-Abe, Ryo Takagi, Satoshi Suda, Kentaro Suzuki, Junya Aoki, Masami Yoneyama, Kazumi Kimura
BACKGROUND AND PURPOSE: It is clinically important to evaluate time course changes in symptomatic middle cerebral artery (MCA) stenotic plaques because of likely recurrence. The objective of this study is to determine whether contrast-enhanced high-resolution magnetic resonance imaging (MRI) is a feasible method for this purpose. METHODS: Contrast-enhanced, high-resolution, 3D turbo spin-echo images with low refocusing flip angle control (3D LOWRAT) applied to 7 patients with symptomatic MCA stenosis were evaluated at the initial (1 month after stroke onset) and follow-up (7 months after stroke onset) stages, and statistical variables, including plaque-to-thalamus signal intensity ratio, degree of stenosis, and stroke recurrence obtained at the 2 stages, were compared...
2018: Journal of Nippon Medical School, Nippon Ika Daigaku Zasshi
Bernadette O Erokwu, Christian E Anderson, Chris A Flask, Katherine M Dell
BACKGROUND: Autosomal Recessive Polycystic Kidney Disease (ARPKD) is associated with significant mortality and morbidity and there are currently no disease-specific treatments available for ARPKD patients. One major limitation in establishing new therapies for ARPKD is a lack of sensitive measures of kidney disease progression. Magnetic Resonance Imaging (MRI) can provide multiple quantitative assessments of disease. METHODS: We applied quantitative image analysis of high resolution (non-contrast) T2-weighted MRI techniques to study cystic kidney disease progression and response to therapy in the PCK rat model of ARPKD...
March 14, 2018: Pediatric Research
A C Van Erp, R A Rebolledo, D Hoeksma, N R Jespersen, P J Ottens, R Nørregaard, M Pedersen, C Laustsen, J G M Burgerhof, J C Wolters, J Ciapaite, H E Bøtker, H G D Leuvenink, B Jespersen
Hepatic and renal energy status prior to transplantation correlates with graft survival. However, effects of brain death (BD) on organ-specific energy status are largely unknown. We studied metabolism, perfusion, oxygen consumption, and mitochondrial function in the liver and kidneys following BD. BD was induced in mechanically-ventilated rats, inflating an epidurally-placed Fogarty-catheter, with sham-operated rats as controls. A 9.4T-preclinical MRI system measured hourly oxygen availability (BOLD-related R2*) and perfusion (T1-weighted)...
March 13, 2018: Scientific Reports
Zona Batacchi, Nicole K Andeen, Subbulaxmi Trikudanathan
A 62-year-old woman presented with an 11-month history of worsening nasal symptoms of rhinorrhoea, anosmia, nasal congestion and intermittent epistaxis. MRI revealed a large mass in the upper nasal vault. Biopsy of the mass revealed an olfactory neuroblastoma. While waiting resection, she acutely developed severe proximal muscle weakness, lethargy and lower extremity oedema. Blood glucose was elevated, and hypokalaemic metabolic alkalosis was noted. Elevated serum cortisol level of 95.7 µg/dL (8.7-22.4 µg/dL) and markedly elevated 24-hour urinary cortisol level of 6962...
March 13, 2018: BMJ Case Reports
Irene Polycarpou, Georgios Soultanidis, Charalampos Tsoumpas
The investigation of the performance of different positron emission tomography (PET) reconstruction and motion compensation methods requires accurate and realistic representation of the anatomy and motion trajectories as observed in real subjects during acquisitions. The generation of well-controlled clinical datasets is difficult due to the many different clinical protocols, scanner specifications, patient sizes, and physiological variations. Alternatively, computational phantoms can be used to generate large data sets for different disease states, providing a ground truth...
March 2018: IEEE Transactions on Medical Imaging
(no author information available yet)
Grecchi E, Veronese M, Bodini B, et al. Multimodal partial volume correction: Application to [11C]PIB PET/MRI myelin imaging in multiple sclerosis. J Cereb Blood Flow Metab 2017; 37: 3803-3817. Three references in the above article appeared with typesetting coding when published online and in print. The references should have appeared as follows: 8. Aston JAD, Cunningham VJ, Asselin M-C, et al. Positron emission tomography partial volume correction: estimation and algorithms. J Cereb Blood Flow Metab 2002; 22: 1019-1034...
January 1, 2018: Journal of Cerebral Blood Flow and Metabolism
Fei Cong, Jia-Wei Wang, Bo Wang, Zhangyan Yang, Jing An, Zhentao Zuo, Zihao Zhang, Yu-Qing Zhang, Yan Zhuo
OBJECTIVES: To image the pedunculopontine tegmental nucleus (PPN), a deep brain stimulation (DBS) target for Parkinson disease, using MRI with validated results. METHODS: This study used the MP2RAGE sequence with high resolution and enhanced grey-white matter contrast on a 7-T ultra-high-field MRI system to image the PPN as well as a diffusion spectrum imaging method on a 3-T MRI system to reconstruct the main fibre systems surrounding the PPN. The coordinates of the rostral and caudal PPN poles of both sides were measured in relation to the third and fourth ventricular landmarks on the 7-T image...
March 12, 2018: European Radiology
Vishwesh Nath, Kurt G Schilling, Prasanna Parvathaneni, Justin Blaber, Allison E Hainline, Zhaohua Ding, Adam Anderson, Bennett A Landman
The diffusion tensor model is nonspecific in regions where micrometer structural patterns are inconsistent at the millimeter scale (i.e., brain regions with pathways that cross, bend, branch, fan, etc.). Numerous models have been proposed to represent crossing fibers and complex intravoxel structure from in vivo diffusion weighted magnetic resonance imaging (e.g., high angular resolution diffusion imaging-HARDI). Here, we present an empirical comparison of two HARDI approaches-persistent angular structure MRI (PAS-MRI) and Q-ball-using a newly acquired reproducibility dataset...
January 2018: Journal of Medical Imaging
Bing Yang, Huili Zhu, Yusheng Zhang, Anding Xu
Intracranial branch atheromatous disease is an atheromatous pathophysiological process associated with occlusion or stenosis at the orifice of a deep penetrating artery. However, apart from autopsy, atherosclerosis in the penetrating artery has not been confirmed in vivo. In this case, we confirmed that the ostium was located in the parent artery plaque and demonstrated the atherosclerosis of the proximal penetrating artery by using high-resolution magnetic resonance imaging. HR-MRI can be used to identify the pathological changes in penetrating arteries and provides more reliable basic information for the clinical subclassification and optimal medical treatment of penetrating artery infarction...
March 9, 2018: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
Linda I Suleiman, Kenneth A Weber, Brett D Rosenthal, Surabhi A Bhatt, Jason W Savage, Wellington K Hsu, Alpesh A Patel, Todd B Parrish
Magnetization transfer (MT) contrast has been established as a marker of myelin integrity, and cervical spondylotic myelopathy is known to cause demyelination. Ten patients with clinical and magnetic resonance imaging (MRI) manifestations of cervical spondylotic myelopathy (CSM) were compared to the MRIs of seven historic healthy controls, using the magnetization transfer ratio (MTR) and Nurick scores as the primary metrics. Transverse slices through the intervertebral discs of the cervical spine were acquired using a gradient echo sequence (MEDIC) with and without an MT saturation pulse on a 3 Tesla Siemens Prisma scanner (TR = 300 ms, TEeff  = 17 ms, flip angle = 30°, in-plane resolution = 0...
March 9, 2018: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
F H Wang, K Bae, Z W Huang, J M Xue
For obtaining high-resolution macroscopical anatomical information and high sensitivity microscopical optical signals, it is highly desirable to develop dual-modality magnetic resonance imaging (MRI) and fluorescent probes in medical imaging simultaneously. In this study, Gd2 O3 nanoparticles were modified with two-photon graphene quantum dots (GQD), integrating a magnetic resonance imaging (MRI) contrast agent with two-photon imaging functionality into one nanoprobe. A photoluminescence study indicated that the GQD modification process integrated MRI properties with both one-photon and two-photon imaging properties...
March 12, 2018: Nanoscale
Cen Zhang, John A Detre, Scott E Kasner, Brett Cucchiara
Objective: The objective of this study is to determine whether structural features of the vertebrobasilar arterial system are related to migraine. Background: Alterations in cerebral vascular structure and function have been associated with migraine, possibly mediated by hypoperfusion and/or endothelial dysfunction triggering cortical spreading depression. Vessel tortuosity, in particular, has been associated with both altered hemodynamics and endothelial function...
2018: Frontiers in Neurology
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