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Zhang M, Olivero WC, Huston JM, Pappu S, Arnold PM, Biswas A, Anderson AT, Sutton BP. Measuring CSF shunt flow with MRI using flow enhancement of signal intensity (FENSI). Magn Reson Med 2024; 92:807-819. [PMID: 38469904 PMCID: PMC11142874 DOI: 10.1002/mrm.30079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/18/2024] [Accepted: 02/21/2024] [Indexed: 03/13/2024]
Abstract
PURPOSE To develop and validate a noninvasive imaging technique for accurately assessing very slow CSF flow within shunt tubes in pediatric patients with hydrocephalus, aiming to identify obstructions that might impede CSF drainage. THEORY AND METHODS A simulation of shunt flow enhancement of signal intensity (shunt-FENSI) signal is used to establish the relationship between signal change and flow rate. The quantification of flow enhancement of signal intensity data involves normalization, curve fitting, and calibration to match simulated data. Additionally, a phase sweep method is introduced to accommodate the impact of magnetic field inhomogeneity on the flow measurement. The method is tested in flow phantoms, healthy adults, intensive care unit patients with external ventricular drains (EVD), and shunt patients. EVDs enable shunt-flow measurements to be acquired with a ground truth measure of CSF drainage. RESULTS The flow-rate-to-signal simulation establishes signal-flow relationships and takes into account the T1 of draining fluid. The phase sweep method accurately accounts for phase accumulation due to frequency offsets at the shunt. Results in phantom and healthy human participants reveal reliable quantification of flow rates using controlled flows and agreement with the flow simulation. EVD patients display reliable measures of flow rates. Shunt patient results demonstrate feasibility of the method and consistent flow rates for functional shunts. CONCLUSION The results demonstrate the technique's applicability, accuracy, and potential for diagnosing and noninvasively monitoring hydrocephalus. Limitations of the current approach include a high sensitivity to motion and strict requirement of imaging slice prescription.
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Affiliation(s)
- Mingxiao Zhang
- Department of Bioengineering, University of Illinois, Urbana, IL, USA
- Beckman Institute, University of Illinois, Urbana, IL, USA
| | - William C. Olivero
- Carle Illinois College of Medicine, University of Illinois, Champaign, IL, USA
- Department of Neurosurgery, Carle Foundation Hospital, Urbana, IL, USA
| | - Jason M. Huston
- Carle Illinois College of Medicine, University of Illinois, Champaign, IL, USA
- Department of Radiology, Carle Foundation Hospital, Urbana, IL, USA
| | - Suguna Pappu
- Carle Illinois College of Medicine, University of Illinois, Champaign, IL, USA
- Department of Neurosurgery, Carle Foundation Hospital, Urbana, IL, USA
| | - Paul M. Arnold
- Carle Illinois College of Medicine, University of Illinois, Champaign, IL, USA
- Department of Neurosurgery, Carle Foundation Hospital, Urbana, IL, USA
| | - Arundhati Biswas
- Department of Neurosurgery, Carle Foundation Hospital, Urbana, IL, USA
| | | | - Bradley P. Sutton
- Department of Bioengineering, University of Illinois, Urbana, IL, USA
- Beckman Institute, University of Illinois, Urbana, IL, USA
- Carle Illinois College of Medicine, University of Illinois, Champaign, IL, USA
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Ouyang C, Sutton BP. Optimizing pTILT perfusion imaging in the presence of off-resonance frequency. J Magn Reson Imaging 2013; 38:210-6. [DOI: 10.1002/jmri.23968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 10/25/2012] [Indexed: 11/09/2022] Open
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Reynaud O, Geffroy F, Ciobanu L. Quantification of microvascular cerebral blood flux and late-stage tumor compartmentalization in 9L gliosarcoma using flow enhanced MRI. NMR IN BIOMEDICINE 2013; 26:699-708. [PMID: 23335424 DOI: 10.1002/nbm.2915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 12/07/2012] [Accepted: 12/07/2012] [Indexed: 06/01/2023]
Abstract
Measurements of tumor microvasculature are important to obtain an understanding of tumor angiogenesis and for the evaluation of therapies. In this work, we characterize the evolution of the microvascular flux at different stages of tumor growth in the 9L rat brain tumor model. The absolute quantification of cerebral blood flux is achieved with MRI at 7 T using the flow enhanced signal intensity (FENSI) method. FENSI flux maps were obtained between 5 and 14 days after glioma cell inoculation. Based on cerebral blood flux maps, we highlighted two main stages of tumor growth, below and above 3 mm, presenting distinct flux patterns and vascular properties. No significant difference emerged from the group analysis performed on the data collected at an early developmental stage (tumor size < 3 mm) when compared with healthy tissue. At a late developmental stage (tumor size > 3 mm), we observed a significant decrease in the cerebral blood flux inside the gliosarcoma (-33%, p < 0.01) and compartmentalization of the tumor (p < 0.05). FENSI flux maps delineated a low-flux tumor core (58 ± 17 μL/min/cm(2) ) and higher vascularized regions around the tumor periphery (85 ± 21 μL/min/cm(2) ). Histology was performed on 11 animals to finely probe the intratumor heterogeneity and microvessel density, and the results were compared with the information derived from FENSI flux maps. The hyper- and hypoperfused tumor regions revealed with FENSI at the late tumor developmental stage correlated well with the ratios of high and low blood vessel density (R(2) = 0.41) and fractional vascular surface (R(2) = 0.67) observed with fluorescence microscopy [cluster of differentiation 31 (CD31) staining].
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Affiliation(s)
- Olivier Reynaud
- Commissariat a l'Energie Atomique/DSV, I2BM, NeuroSpin, LRMN, Gif sur Yvette, France
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