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Validation of In Vivo Nodal Assessment of Solid Malignancies with USPIO-Enhanced MRI: A Workflow Protocol. Methods Protoc 2022; 5:mps5020024. [PMID: 35314661 PMCID: PMC8938816 DOI: 10.3390/mps5020024] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/25/2022] [Accepted: 03/04/2022] [Indexed: 01/12/2023] Open
Abstract
Background: In various cancer types, the first step towards extended metastatic disease is the presence of lymph node metastases. Imaging methods with sufficient diagnostic accuracy are required to personalize treatment. Lymph node metastases can be detected with ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance imaging (MRI), but this method needs validation. Here, a workflow is presented, which is designed to compare MRI-visible lymph nodes on a node-to-node basis with histopathology. Methods: In patients with prostate, rectal, periampullary, esophageal, and head-and-neck cancer, in vivo USPIO-enhanced MRI was performed to detect lymph nodes suspicious of harboring metastases. After lymphadenectomy, but before histopathological assessment, a 7 Tesla preclinical ex vivo MRI of the surgical specimen was performed, and in vivo MR images were radiologically matched to ex vivo MR images. Lymph nodes were annotated on the ex vivo MRI for an MR-guided pathological examination of the specimens. Results: Matching lymph nodes of ex vivo MRI to pathology was feasible in all cancer types. The annotated ex vivo MR images enabled a comparison between USPIO-enhanced in vivo MRI and histopathology, which allowed for analyses on a nodal, or at least on a nodal station, basis. Conclusions: A workflow was developed to validate in vivo USPIO-enhanced MRI with histopathology. Guiding the pathologist towards lymph nodes in the resection specimens during histopathological work-up allowed for the analysis at a nodal basis, or at least nodal station basis, of in vivo suspicious lymph nodes with corresponding histopathology, providing direct information for validation of in vivo USPIO-enhanced, MRI-detected lymph nodes.
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2
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Mills M, van Zanten M, Borri M, Mortimer PS, Gordon K, Ostergaard P, Howe FA. Systematic Review of Magnetic Resonance Lymphangiography From a Technical Perspective. J Magn Reson Imaging 2021; 53:1766-1790. [PMID: 33625795 PMCID: PMC7611641 DOI: 10.1002/jmri.27542] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/22/2021] [Accepted: 01/25/2021] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Clinical examination and lymphoscintigraphy are the current standard for investigating lymphatic function. Magnetic resonance imaging (MRI) facilitates three-dimensional (3D), nonionizing imaging of the lymphatic vasculature, including functional assessments of lymphatic flow, and may improve diagnosis and treatment planning in disease states such as lymphedema. PURPOSE To summarize the role of MRI as a noninvasive technique to assess lymphatic drainage and highlight areas in need of further study. STUDY TYPE Systematic review. POPULATION In October 2019, a systematic literature search (PubMed) was performed to identify articles on magnetic resonance lymphangiography (MRL). FIELD STRENGTH/SEQUENCE No field strength or sequence restrictions. ASSESSMENT Article quality assessment was conducted using a bespoke protocol, designed with heavy reliance on the National Institutes of Health quality assessment tool for case series studies and Downs and Blacks quality checklist for health care intervention studies. STATISTICAL TESTS The results of the original research articles are summarized. RESULTS From 612 identified articles, 43 articles were included and their protocols and results summarized. Field strength was 1.5 or 3.0 T in all studies, with 25/43 (58%) employing 3.0 T imaging. Most commonly, imaging of the peripheries, upper and lower limbs including the pelvis (32/43, 74%), and the trunk (10/43, 23%) is performed, including two studies covering both regions. Imaging protocols were heterogenous; however, T2 -weighted and contrast-enhanced T1 -weighted images are routinely acquired and demonstrate the lymphatic vasculature. Edema, vessel, quantity and morphology, and contrast uptake characteristics are commonly reported indicators of lymphatic dysfunction. DATA CONCLUSION MRL is uniquely placed to yield large field of view, qualitative and quantitative, 3D imaging of the lymphatic vasculature. Despite study heterogeneity, consensus is emerging regarding MRL protocol design. MRL has the potential to dramatically improve understanding of the lymphatics and detect disease, but further optimization, and research into the influence of study protocol differences, is required before this is fully realized. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Michael Mills
- Molecular and Clinical Sciences Research Institute, St George’s University, London, UK
| | - Malou van Zanten
- Molecular and Clinical Sciences Research Institute, St George’s University, London, UK
| | - Marco Borri
- Molecular and Clinical Sciences Research Institute, St George’s University, London, UK
- Department of Neuroradiology, King’s College Hospital, London, UK
| | - Peter S. Mortimer
- Molecular and Clinical Sciences Research Institute, St George’s University, London, UK
| | - Kristiana Gordon
- Lymphovascular Medicine, Dermatology Department, St George’s Hospital, London, UK
| | - Pia Ostergaard
- Molecular and Clinical Sciences Research Institute, St George’s University, London, UK
| | - Franklyn A. Howe
- Molecular and Clinical Sciences Research Institute, St George’s University, London, UK
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3
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Donahue PMC, Crescenzi R, Lee C, Garza M, Patel NJ, Petersen KJ, Donahue MJ. Magnetic resonance imaging and bioimpedance evaluation of lymphatic abnormalities in patients with breast cancer treatment-related lymphedema. Breast Cancer Res Treat 2020; 183:83-94. [PMID: 32601969 DOI: 10.1007/s10549-020-05765-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/20/2020] [Indexed: 02/08/2023]
Abstract
PURPOSE Breast cancer treatment-related lymphedema (BCRL) evaluation is frequently performed using portable measures of limb volume and bioimpedance asymmetry. Here quantitative magnetic resonance imaging (MRI) is applied to evaluate deep and superficial tissue impairment, in both surgical and contralateral quadrants, to test the hypothesis that BCRL impairment is frequently bilateral and extends beyond regions commonly evaluated with portable external devices. METHODS 3-T MRI was applied to investigate BCRL topographical impairment. Female BCRL (n = 33; age = 54.1 ± 11.2 years; stage = 1.5 ± 0.8) and healthy (n = 33; age = 49.4 ± 11.0 years) participants underwent quantitative upper limb MRI relaxometry (T2), bioimpedance asymmetry, arm volume asymmetry, and physical evaluation. Parametric tests were applied to evaluate study measurements (i) between BCRL and healthy participants, (ii) between surgical and contralateral limbs, and (iii) in relation to clinical indicators of disease severity. Two-sided p-value < 0.05 was required for significance. RESULTS Bioimpedance asymmetry was significantly correlated with MRI-measured water relaxation (T2) in superficial tissue. Deep muscle (T2 = 37.6 ± 3.5 ms) and superficial tissue (T2 = 49.8 ± 13.2 ms) relaxation times were symmetric in healthy participants. In the surgical limbs of BCRL participants, deep muscle (T2 = 40.5 ± 4.9 ms) and superficial tissue (T2 = 56.0 ± 14.8 ms) relaxation times were elevated compared to healthy participants, consistent with an edematous micro-environment. This elevation was also observed in contralateral limbs of BCRL participants (deep muscle T2 = 40.3 ± 5.7 ms; superficial T2 = 56.6 ± 13.8 ms). CONCLUSIONS Regional MRI measures substantiate a growing literature speculating that superficial and deep tissue, in surgical and contralateral quadrants, is affected in BCRL. The implications of these findings in the context of titrating treatment regimens and understanding malignancy recurrence are discussed.
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Affiliation(s)
- Paula M C Donahue
- Physical Medicine and Rehabilitation, Vanderbilt University Medical Center, Nashville, TN, USA.,Vanderbilt Dayani Center for Health and Wellness, Nashville, TN, USA
| | - Rachelle Crescenzi
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Chelsea Lee
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Maria Garza
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Niral J Patel
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kalen J Petersen
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Manus J Donahue
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA. .,Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA. .,Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
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4
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Ianuş A, Santiago I, Galzerano A, Montesinos P, Loução N, Sanchez-Gonzalez J, Alexander DC, Matos C, Shemesh N. Higher-order diffusion MRI characterization of mesorectal lymph nodes in rectal cancer. Magn Reson Med 2019; 84:348-364. [PMID: 31850546 DOI: 10.1002/mrm.28102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/05/2019] [Accepted: 11/07/2019] [Indexed: 01/02/2023]
Abstract
PURPOSE Mesorectal lymph node staging plays an important role in treatment decision making. Here, we explore the benefit of higher-order diffusion MRI models accounting for non-Gaussian diffusion effects to classify mesorectal lymph nodes both 1) ex vivo at ultrahigh field correlated with histology and 2) in vivo in a clinical scanner upon patient staging. METHODS The preclinical investigation included 54 mesorectal lymph nodes, which were scanned at 16.4 T with an extensive diffusion MRI acquisition. Eight diffusion models were compared in terms of goodness of fit, lymph node classification ability, and histology correlation. In the clinical part of this study, 10 rectal cancer patients were scanned with diffusion MRI at 1.5 T, and 72 lymph nodes were analyzed with Apparent Diffusion Coefficient (ADC), Intravoxel Incoherent Motion (IVIM), Kurtosis, and IVIM-Kurtosis. RESULTS Compartment models including restricted and anisotropic diffusion improved the preclinical data fit, as well as the lymph node classification, compared to standard ADC. The comparison with histology revealed only moderate correlations, and the highest values were observed between diffusion anisotropy metrics and cell area fraction. In the clinical study, the diffusivity from IVIM-Kurtosis was the only metric showing significant differences between benign (0.80 ± 0.30 μm2 /ms) and malignant (1.02 ± 0.41 μm2 /ms, P = .03) nodes. IVIM-Kurtosis also yielded the largest area under the receiver operating characteristic curve (0.73) and significantly improved the node differentiation when added to the standard visual analysis by experts based on T2 -weighted imaging. CONCLUSION Higher-order diffusion MRI models perform better than standard ADC and may be of added value for mesorectal lymph node classification in rectal cancer patients.
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Affiliation(s)
- Andrada Ianuş
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal.,Centre for Medical Image Computing, University College London, London, United Kingdom
| | - Ines Santiago
- Champalimaud Clinical Centre, Champalimaud Centre for the Unknown, Lisbon, Portugal.,Nova Medical School, Lisbon, Portugal
| | - Antonio Galzerano
- Champalimaud Clinical Centre, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | | | | | | | - Daniel C Alexander
- Centre for Medical Image Computing, University College London, London, United Kingdom
| | - Celso Matos
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal.,Champalimaud Clinical Centre, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Noam Shemesh
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal
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5
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Crescenzi R, Donahue PMC, Mahany H, Lants SK, Donahue MJ. CEST MRI quantification procedures for breast cancer treatment-related lymphedema therapy evaluation. Magn Reson Med 2019; 83:1760-1773. [PMID: 31631410 DOI: 10.1002/mrm.28031] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 09/14/2019] [Accepted: 09/16/2019] [Indexed: 12/31/2022]
Abstract
PURPOSE To quantify chemical exchange saturation transfer contrast in upper extremities of participants with lymphedema before and after standardized lymphatic mobilization therapy using correction procedures for B0 and B1 heterogeneity, and T1 relaxation. METHODS Females with (n = 12) and without (n = 17) breast cancer treatment-related lymphedema (BCRL) matched for age and body mass index were scanned at 3.0T MRI. B1 efficiency and T1 were calculated in series with chemical exchange saturation transfer in bilateral axilla (B1 amplitude = 2µT, Δω = ±5.5 ppm, slices = 9, spatial resolution = 1.8 × 1.47 × 5.5 mm3 ). B1 dispersion measurements (B1 = 1-3 µT; increment = 0.5 µT) were performed in controls (n = 6 arms in 3 subjects). BCRL participants were scanned pre- and post-manual lymphatic drainage (MLD) therapy. Chemical exchange saturation transfer amide proton transfer (APT) and nuclear Overhauser effect (NOE) metrics corrected for B1 efficiency were calculated, including proton transfer ratio (PTR'), magnetization transfer ratio asymmetry ( M T R asymmetry ' ) , and apparent exchange-dependent relaxation (AREX'). Nonparametric tests were used to evaluate relationships between metrics in BCRL participants pre- versus post-MLD (two-sided P < 0.05 required for significance). RESULTS B1 dispersion experiments showed nonlinear dependence of Z-values on B1 efficiency in the upper extremities; PTR' showed < 1% mean fractional difference between subject-specific and group-level correction procedures. PTR'APT significantly correlated with T1 (Spearman's rho = 0.57, P < 0.001) and body mass index (Spearman's rho = -0.37, P = 0.029) in controls and with lymphedema stage (Spearman's rho = 0.48, P = 0.017) in BCRL participants. Following MLD therapy, PTR'APT significantly increased in the affected arm of BCRL participants (pre- vs. post-MLD: 0.41 ± 0.05 vs. 0.43 ± 0.03, P = 0.02), consistent with treatment effects from mobilized lymphatic fluid. CONCLUSION Chemical exchange saturation transfer metrics, following appropriate correction procedures, respond to lymphatic mobilization therapies and may have potential for evaluating treatments in participants with secondary lymphedema.
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Affiliation(s)
- Rachelle Crescenzi
- Department of Radiology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Paula M C Donahue
- Physical Medicine and Rehabilitation, Vanderbilt University Medical Center, Nashville, Tennessee.,Vanderbilt Dayani Center for Health and Wellness, Nashville, Tennessee
| | - Helen Mahany
- Department of Radiology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Sarah K Lants
- Department of Radiology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Manus J Donahue
- Department of Radiology, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Psychiatry, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Neurology, Vanderbilt University Medical Center, Nashville, Tennessee
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He Y, Qin S, Dyer BA, Zhang H, Zhao L, Chen T, Zheng F, Sun Y, Shi L, Rong Y, Qiu J. Characterizing mechanical and medical imaging properties of polyvinyl chloride-based tissue-mimicking materials. J Appl Clin Med Phys 2019; 20:176-183. [PMID: 31207035 PMCID: PMC6612694 DOI: 10.1002/acm2.12661] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 04/25/2019] [Accepted: 05/23/2019] [Indexed: 01/09/2023] Open
Abstract
Polyvinyl chloride (PVC) is a commonly used tissue‐mimicking material (TMM) for phantom construction using 3D printing technology. PVC‐based TMMs consist of a mixture of PVC powder and dioctyl terephthalate as a softener. In order to allow the clinical use of a PVC‐based phantom use across CT and magnetic resonance imaging (MRI) imaging platforms, we evaluated the mechanical and physical imaging characteristics of ten PVC samples. The samples were made with different PVC‐softener ratios to optimize phantom bioequivalence with physiologic human tissue. Phantom imaging characteristics, including computed tomography (CT) number, MRI relaxation time, and mechanical properties (e.g., Poisson’s ratio and elastic modulus) were quantified. CT number varied over a range of approximately −10 to 110 HU. The relaxation times of the T1‐weighted and T2‐weighted images were 206.81 ± 17.50 and 20.22 ± 5.74 ms, respectively. Tensile testing was performed to evaluate mechanical properties on the three PVC samples that were closest to human tissue. The elastic moduli for these samples ranged 7.000–12.376 MPa, and Poisson’s ratios were 0.604–0.644. After physical and imaging characterization of the various PVC‐based phantoms, we successfully produced a bioequivalent phantom compatible with multimodal imaging platforms for machine calibration and image optimization/benchmarking. By combining PVC with 3D printing technologies, it is possible to construct imaging phantoms simulating human anatomies with tissue equivalency.
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Affiliation(s)
- Yaoyao He
- Medical engineering and technology center, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China.,Imaging-X Joint laboratory, Taian, China.,Radiology Department, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Shengxue Qin
- College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao, China
| | - Brandon A Dyer
- Department of Radiation Oncology, University of California Davis Medical Center, Sacramento, CA, USA
| | - Hongbin Zhang
- College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao, China
| | - Lifen Zhao
- School of Material Science and Engineering, Shandong University of Science and Technology, Qingdao, China
| | - Tiao Chen
- Medical engineering and technology center, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China.,Imaging-X Joint laboratory, Taian, China.,Radiology Department, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China.,Department of Radiology, Hubei Cancer Hospital, Wuhan, China
| | - Fenglian Zheng
- Medical engineering and technology center, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China.,Imaging-X Joint laboratory, Taian, China.,Radiology Department, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Yong Sun
- Radiology Department, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Liting Shi
- Medical engineering and technology center, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China.,Imaging-X Joint laboratory, Taian, China.,Radiology Department, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Yi Rong
- Department of Radiation Oncology, University of California Davis Medical Center, Sacramento, CA, USA
| | - Jianfeng Qiu
- Medical engineering and technology center, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China.,Imaging-X Joint laboratory, Taian, China.,Radiology Department, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
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7
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Stouthandel MEJ, Veldeman L, Van Hoof T. Call for a Multidisciplinary Effort to Map the Lymphatic System with Advanced Medical Imaging Techniques: A Review of the Literature and Suggestions for Future Anatomical Research. Anat Rec (Hoboken) 2019; 302:1681-1695. [PMID: 31087787 DOI: 10.1002/ar.24143] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 01/21/2019] [Accepted: 03/09/2019] [Indexed: 12/13/2022]
Abstract
This review intends to rekindle efforts to map the lymphatic system by using a more modern approach, based on medical imaging. The structure, function, and pathologies associated with the lymphatic system are first discussed to highlight the need for more accurately mapping the lymphatic system. Next, the need for an interdisciplinary approach, with a central role for the anatomist, to come up with better maps of the lymphatic system is emphasized. The current approaches on lymphatic system research involving medical imaging will be discussed and suggestions will be made for an all-encompassing effort to thoroughly map the entire lymphatic system. A first-hand account of our integration as anatomists in the radiotherapy department is given as an example of interdisciplinary collaboration. From this account, it will become clear that the interdisciplinary collaboration of anatomists in the clinical disciplines involved in lymphatic system research/treatment still holds great promise in terms of improving clinical regimens that are currently being employed. As such, we hope that our fellow anatomists will join us in an interdisciplinary effort to map the lymphatic system, because this could, in a relatively short timeframe, provide improved treatment options for patients with cancer or lymphatic pathologies all over the world. Anat Rec, 302:1681-1695, 2019. © 2019 American Association for Anatomy.
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Affiliation(s)
| | - Liv Veldeman
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium.,Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium
| | - Tom Van Hoof
- Department of Human Structure and Repair, Ghent University, Ghent, Belgium
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Crescenzi R, Donahue PM, Braxton VG, Scott AO, Mahany HB, Lants SK, Donahue MJ. 3.0 T relaxation time measurements of human lymph nodes in adults with and without lymphatic insufficiency: Implications for magnetic resonance lymphatic imaging. NMR IN BIOMEDICINE 2018; 31:e4009. [PMID: 30311705 PMCID: PMC6263822 DOI: 10.1002/nbm.4009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 07/03/2018] [Accepted: 07/24/2018] [Indexed: 06/08/2023]
Abstract
The purpose of this work was to quantify 3.0 T (i) T1 and T2 relaxation times of in vivo human lymph nodes (LNs) and (ii) LN relaxometry differences between healthy LNs and LNs from patients with lymphatic insufficiency secondary to breast cancer treatment-related lymphedema (BCRL). MR relaxometry was performed over bilateral axillary regions at 3.0 T in healthy female controls (105 LNs from 20 participants) and patients with BCRL (108 LNs from 20 participants). Quantitative T1 maps were calculated using a multi-flip-angle (20, 40, 60°) method with B1 correction (dual-TR method, TR1 /TR2 = 30/130 ms), and T2 maps using a multi-echo (TE = 9-189 ms; 12 ms intervals) method. T1 and T2 were quantified in the LN cortex and hilum. A Mann-Whitney U-test was applied to compare LN relaxometry values between patients and controls (significance, two sided, p < 0.05). Linear regression was applied to evaluate how LN relaxometry varied with age, BMI, and clinical indicators of disease. LN substructure relaxation times (mean ± standard deviation) in healthy controls were T1 cortex, 1435 ± 391 ms; T1 hilum, 714 ± 123 ms; T2 cortex, 102 ± 12 ms, and T2 hilum, 119 ± 21 ms. T1 of the LN cortex was significantly reduced in the contralateral axilla of BCRL patients compared with the axilla on the surgical side (p < 0.001) and compared with bilateral control values (p < 0.01). The LN cortex T1 asymmetry discriminated cases from controls (p = 0.004) in a multiple linear regression, accounting for age and BMI. Human 3.0 T T1 and T2 relaxation times in axillary LNs were quantified for the first time in vivo. Measured values are relevant for optimizing acquisition parameters in anatomical lymphatic imaging sequences, and can serve as a reference for novel functional and molecular LN imaging methods that require quantitative knowledge of LN relaxation times.
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Affiliation(s)
- Rachelle Crescenzi
- Vanderbilt University Medical Center, Radiology and Radiological Sciences, Nashville, TN, USA
| | - Paula M. Donahue
- Physical Medicine and Rehabilitation, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Dayani Center for Health and Wellness, Nashville, TN, USA
| | - Vaughn G. Braxton
- Vanderbilt University Medical Center, Radiology and Radiological Sciences, Nashville, TN, USA
| | - Allison O. Scott
- Vanderbilt University Medical Center, Radiology and Radiological Sciences, Nashville, TN, USA
| | - Helen B. Mahany
- Vanderbilt University Medical Center, Radiology and Radiological Sciences, Nashville, TN, USA
| | - Sarah K. Lants
- Vanderbilt University Medical Center, Radiology and Radiological Sciences, Nashville, TN, USA
| | - Manus J. Donahue
- Vanderbilt University Medical Center, Radiology and Radiological Sciences, Nashville, TN, USA
- Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
- Psychiatry, Vanderbilt University Medical Center, Nashville, TN, USA
- Physics and Astronomy, Vanderbilt University, Nashville, TN, USA
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Donahue PMC, Crescenzi R, Scott AO, Braxton V, Desai A, Smith SA, Jordi J, Meszoely IM, Grau AM, Kauffmann RM, Sweeting RS, Spotanski K, Ridner SH, Donahue MJ. Bilateral Changes in Deep Tissue Environment After Manual Lymphatic Drainage in Patients with Breast Cancer Treatment-Related Lymphedema. Lymphat Res Biol 2017; 15:45-56. [PMID: 28323572 DOI: 10.1089/lrb.2016.0020] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Breast cancer treatment-related lymphedema (BCRL) arises from a mechanical insufficiency following cancer therapies. Early BCRL detection and personalized intervention require an improved understanding of the physiological processes that initiate lymphatic impairment. Here, internal magnetic resonance imaging (MRI) measures of the tissue microenvironment were paired with clinical measures of tissue structure to test fundamental hypotheses regarding structural tissue and muscle changes after the commonly used therapeutic intervention of manual lymphatic drainage (MLD). METHODS AND RESULTS Measurements to identify lymphatic dysfunction in healthy volunteers (n = 29) and patients with BCRL (n = 16) consisted of (1) limb volume, tissue dielectric constant, and bioelectrical impedance (i.e., non-MRI measures); (2) qualitative 3 Tesla diffusion-weighted, T1-weighted and T2-weighted MRI; and (3) quantitative multi-echo T2 MRI of the axilla. Measurements were repeated in patients immediately following MLD. Normative control and BCRL T2 values were quantified and a signed Wilcoxon Rank-Sum test was applied (significance: two-sided p < 0.05). Non-MRI measures yielded significant capacity for discriminating between arms with versus without clinical signs of BCRL, yet yielded no change in response to MLD. Alternatively, a significant increase in deep tissue T2 on the involved (pre T2 = 0.0371 ± 0.003 seconds; post T2 = 0.0389 ± 0.003; p = 0.029) and contralateral (pre T2 = 0.0365 ± 0.002; post T2 = 0.0395 ± 0.002; p < 0.01) arms was observed. Trends for larger T2 increases on the involved side after MLD in patients with stage 2 BCRL relative to earlier stages 0 and 1 BCRL were observed, consistent with tissue composition changes in later stages of BCRL manifesting as breakdown of fibrotic tissue after MLD in the involved arm. Contrast consistent with relocation of fluid to the contralateral quadrant was observed in all stages. CONCLUSION Quantitative deep tissue T2 MRI values yielded significant changes following MLD treatment, whereas non-MRI measurements did not vary. These findings highlight that internal imaging measures of tissue composition may be useful for evaluating how current and emerging therapies impact tissue function.
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Affiliation(s)
- Paula M C Donahue
- 1 Department of Physical Medicine and Rehabilitation, Vanderbilt University Medical Center , Nashville, Tennessee.,2 Vanderbilt Dayani Center for Health and Wellness , Nashville, Tennessee
| | - Rachelle Crescenzi
- 3 Department of Radiology, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Allison O Scott
- 3 Department of Radiology, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Vaughn Braxton
- 3 Department of Radiology, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Aditi Desai
- 3 Department of Radiology, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Seth A Smith
- 3 Department of Radiology, Vanderbilt University Medical Center , Nashville, Tennessee
| | - John Jordi
- 4 Benchmark Physical Therapy , Chattanooga, Tennessee
| | - Ingrid M Meszoely
- 5 Department of Surgical Oncology, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Ana M Grau
- 5 Department of Surgical Oncology, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Rondi M Kauffmann
- 5 Department of Surgical Oncology, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Raeshell S Sweeting
- 5 Department of Surgical Oncology, Vanderbilt University Medical Center , Nashville, Tennessee
| | | | | | - Manus J Donahue
- 3 Department of Radiology, Vanderbilt University Medical Center , Nashville, Tennessee.,7 Department of Psychiatry, Vanderbilt University Medical Center , Nashville, Tennessee.,8 Department of Neurology, Vanderbilt University Medical Center , Nashville, Tennessee.,9 Department of Physics and Astronomy, Vanderbilt University , Nashville, Tennessee
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10
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Evaluation of tongue squamous cell carcinoma resection margins using ex-vivo MR. Int J Comput Assist Radiol Surg 2017; 12:821-828. [PMID: 28130702 PMCID: PMC5420007 DOI: 10.1007/s11548-017-1524-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 01/06/2017] [Indexed: 01/13/2023]
Abstract
Purpose Purpose of this feasibility study was (1) to evaluate whether application of ex-vivo 7T MR of the resected tongue specimen containing squamous cell carcinoma may provide information on the resection margin status and (2) to evaluate the research and developmental issues that have to be solved for this technique to have the beneficial impact on clinical outcome that we expect: better oncologic and functional outcomes, better quality of life, and lower costs. Methods We performed a non-blinded validation of ex-vivo 7T MR to detect the tongue squamous cell carcinoma and resection margin in 10 fresh tongue specimens using histopathology as gold standard. Results In six of seven specimens with a histopathologically determined invasion depth of the tumor of \documentclass[12pt]{minimal}
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\begin{document}$${\ge }3$$\end{document}≥3 mm, the tumor could be recognized on MR, with a resection margin within a 2 mm range as compared to histopathology. In three specimens with an invasion depth of \documentclass[12pt]{minimal}
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\begin{document}$${<}1$$\end{document}<1 mm, the tumor was not visible on MR. Technical limitations mainly included scan time, image resolution, and the fact that we used a less available small-bore 7T MR machine. Conclusion Ex-vivo 7T probably will have a low negative predictive value but a high positive predictive value, meaning that in tumors thicker than a few millimeters we expect to be able to predict whether the resection margin is too small. A randomized controlled trial needs to be performed to show our hypothesis: better oncologic and functional outcomes, better quality of life, and lower costs.
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van Heijst TCF, van Asselen B, Pijnappel RM, Cloos-van Balen M, Lagendijk JJW, van den Bongard D, Philippens MEP. MRI sequences for the detection of individual lymph nodes in regional breast radiotherapy planning. Br J Radiol 2016; 89:20160072. [PMID: 27164032 DOI: 10.1259/bjr.20160072] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE In regional radiotherapy (RT) for patients with breast cancer, lymph node (LN) targets are delineated on CT, defined by anatomical boundaries. By identifying individual LNs, MRI-based delineations may reduce target volumes and thereby toxicity. We optimized MRI sequences for this purpose. Our aim was to evaluate the techniques for LN delineation in RT planning. METHODS Supine MRI was explored at 1.5 T in RT position (arms in abduction). 5 MRI techniques were optimized in 10 and evaluated in 12 healthy female volunteers. The scans included one T1 weighted (T1w), three T2 weighted (T2w) and a diffusion-weighted imaging (DWI) technique. Quantitative evaluation was performed by scoring LN numbers per volunteer and per scan. Qualitatively, scans were assessed on seven aspects, including LN contrast, anatomical information and insensitivity to motion during acquisition. RESULTS Two T2w fast spin-echo (FSE) methods showed the highest LN numbers (median 24 axillary), high contrast, excellent fat suppression and relative insensitivity to motion during acquisition. A third T2w sequence and DWI showed significantly fewer LNs (14 and 10) and proved unsuitable due to motion sensitivity and geometrical uncertainties. T1w MRI showed an intermediate number of LNs (17), provided valuable anatomical information, but lacked LN contrast. CONCLUSION Explicit LN imaging was achieved, in supine RT position, using MRI. Two T2w FSE techniques had the highest detection rates and were motion insensitive. T1w MRI showed anatomical information. MRI enables direct delineation of individual LNs. ADVANCES IN KNOWLEDGE Our optimized MRI scans enable accurate target definition in MRI-guided regional breast RT and development of personalized treatments.
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Affiliation(s)
| | - Bram van Asselen
- 1 Department of Radiotherapy, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Ruud M Pijnappel
- 2 Department of Radiology, University Medical Centre Utrecht, Utrecht, Netherlands
| | | | - Jan J W Lagendijk
- 1 Department of Radiotherapy, University Medical Centre Utrecht, Utrecht, Netherlands
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The Potential of High Resolution Magnetic Resonance Microscopy in the Pathologic Analysis of Resected Breast and Lymph Tissue. Sci Rep 2015; 5:17435. [PMID: 26639673 PMCID: PMC4671009 DOI: 10.1038/srep17435] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 10/29/2015] [Indexed: 11/25/2022] Open
Abstract
Pathologic evaluation of breast specimens requires a fixation and staining procedure of at least 12 hours duration, delaying diagnosis and post-operative planning. Here we introduce an MRI technique with a custom-designed radiofrequency resonator for imaging breast and lymph tissue with sufficient spatial resolution and speed to guide pathologic interpretation and offer value in clinical decision making. In this study, we demonstrate the ability to image breast and lymphatic tissue using 7.0 Tesla MRI, achieving a spatial resolution of 59 × 59 × 94 μm3 with a signal-to-noise ratio of 15–20, in an imaging time of 56 to 70 minutes. These are the first MR images to reveal characteristic pathologic features of both benign and malignant breast and lymph tissue, some of which were discernible by blinded pathologists who had no prior training in high resolution MRI interpretation.
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Detection of axillary lymph node metastasis with diffusion-weighted MR imaging. Clin Imaging 2014; 38:633-6. [DOI: 10.1016/j.clinimag.2014.04.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 03/26/2014] [Accepted: 04/23/2014] [Indexed: 02/06/2023]
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De Cocker LJL, van Veluw SJ, Biessels GJ, Spliet WGM, Thunnissen IE, Luijten PR, Hendrikse J, Zwanenburg JJM. Ischaemic cavities in the cerebellum: an ex vivo 7-tesla MRI study with pathological correlation. Cerebrovasc Dis 2014; 38:17-23. [PMID: 25171512 DOI: 10.1159/000365411] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 06/23/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Small cerebellar cavities (≤15 mm) are often observed coincidentally in ageing subjects and have also been associated with migraine. Although generally assumed to be of ischaemic origin, descriptive imaging studies are sparse and imaging findings have not been correlated with histopathology. We aimed to investigate whether small ischaemic cavities in the cerebellum show characteristic infarct patterns that might be helpful for diagnostic imaging. METHODS We examined 40 whole postmortem cerebella with 7-tesla MRI ex vivo for the presence of small ischaemic cavities. The scan protocol included a T2-, T2*- and fluid-attenuated inversion recovery-weighted sequence for all specimens. We investigated to which degree small ischaemic cavities affect the cortical, juxtacortical and/or deep subcortical regions of the cerebellum. In a subset of the cavities identified, we correlated the imaging data with histopathological findings. This was performed by cutting the particular cerebellar specimen into 5-mm-thick slices. Serial sections were performed if cavities remained unidentified macroscopically. RESULTS Twenty-two cavities were seen on ex vivo MRI in 8 out of 40 examined cerebella. Twenty out of 22 cerebellar cavities were located in the cortex, and only 2 in the deep white matter, with no cavities located in the juxtacortical white matter. None of the 20 cerebellar cortical cavities showed extension into the juxtacortical white matter on MRI, although in 1 cortical cavity some surrounding gliosis was seen to extend into the juxtacortical white matter. Nine out of 22 cavities were sampled for pathological correlation, including 7 cerebellar cortical cavities and both cavities or lacunes in the deep white matter. Three out of 7 cortical and both the deep cavities were histopathologically verified as cavities of ischaemic origin, while the remaining cortical cavities could not be retrieved upon histopathologic examination. Some microscopic gliosis was seen to extend into the juxtacortical white matter of all confirmed cortical cavities. CONCLUSION Knowledge of typical infarct patterns may facilitate the detection and characterisation of cerebellar ischaemic cavities in vivo. Cerebellar cortical cavities appeared to be much more common than deep cavities and presented on imaging as a full-thickness defect in the cerebellar cortex without extension in the adjacent white matter.
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Affiliation(s)
- Laurens J L De Cocker
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
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15
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Freitag MT, Breithaupt M, Berger M, Umathum R, Nagel AM, Hassel J, Ladd ME, Schlemmer HP, Semmler W, Stieltjes B. In vivo visualization of mesoscopic anatomy of healthy and pathological lymph nodes using 7T MRI: A feasibility study. J Magn Reson Imaging 2014; 41:1405-12. [DOI: 10.1002/jmri.24686] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 06/11/2014] [Accepted: 06/11/2014] [Indexed: 01/27/2023] Open
Affiliation(s)
- Martin T. Freitag
- Section Quantitative Imaging Based Disease Characterization, Department of Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Mathies Breithaupt
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Moritz Berger
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Reiner Umathum
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Armin M. Nagel
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Jessica Hassel
- Department of Dermatology; National Center for Tumor Diseases (NCT), University of Heidelberg; Heidelberg Germany
| | - Mark E. Ladd
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | | | - Wolfhard Semmler
- Division of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Bram Stieltjes
- Section Quantitative Imaging Based Disease Characterization, Department of Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
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Kinner S, Maderwald S, Albert J, Parohl N, Corot C, Robert P, Baba HA, Barkhausen J. Discrimination of benign and malignant lymph nodes at 7.0T compared to 1.5T magnetic resonance imaging using ultrasmall particles of iron oxide: a feasibility preclinical study. Acad Radiol 2013; 20:1604-9. [PMID: 24200489 DOI: 10.1016/j.acra.2013.09.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 08/31/2013] [Accepted: 09/01/2013] [Indexed: 11/17/2022]
Abstract
RATIONALE AND OBJECTIVES To investigate the feasibility and performance of 7T magnetic resonance imaging compared to 1.5T imaging to discriminate benign (normal and inflammatory changed) from tumor-bearing lymph nodes in rabbits using ultrasmall particles of iron oxide (USPIO)-based contrast agents. MATERIALS AND METHODS Six New Zealand White rabbits were inoculated with either complete Freund's adjuvant cell suspension (n = 3) to induce reactively enlarged lymph nodes or with VX2 tumor cells to produce metastatic lymph nodes (n = 3). Image acquisition was performed before and 24 hours after bolus injection of an USPIO contrast agent at 1.5T and afterward at 7T using T1-weighted and T2*-weighted sequences. Sensitivities, specificities, and negative and positive predictive values for the detection of lymph node metastases were calculated for both field strengths with histopathology serving as reference standard. Sizes of lymph nodes with no, inflammatory, and malignant changes were compared using a Mann-Whitney U-test. RESULTS All 24 lymph nodes were detected at 1.5T as well as at 7T. At 1.5T, sensitivity amounted to 0.67, while specificity reached a value of 1. At the higher field strength (7T), imaging was able to reach sensitivity and specificity values of 1. No statistical differences were detected concerning lymph node sizes. CONCLUSIONS Magnetic resonance lymphography with USPIO contrast agents allows for differentiation of normal and reactively enlarged lymph nodes compared to metastatic nodes. First experiments at 7T show promising results compared to 1.5T, which have to be evaluated in further trials.
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Affiliation(s)
- Sonja Kinner
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45122 Essen, Germany.
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He N, Xie C, Wei W, Pan C, Wang W, Lv N, Wu P. A new, preoperative, MRI-based scoring system for diagnosing malignant axillary lymph nodes in women evaluated for breast cancer. Eur J Radiol 2012; 81:2602-12. [DOI: 10.1016/j.ejrad.2012.03.019] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 10/20/2011] [Indexed: 02/06/2023]
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de Bazelaire C, Groheux D, Chapellier M, Sabatier F, Scémama A, Pluvinage A, Albiter M, de Kerviler E. Breast inflammation: Indications for MRI and PET-CT. Diagn Interv Imaging 2012; 93:104-15. [DOI: 10.1016/j.diii.2011.12.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Korteweg MA, Veldhuis WB, Mali WP, Diepstraten SC, Luijten PR, van den Bosch MA, Eijkemans RM, van Diest PJ, Klomp DW. Investigation of lipid composition of dissected sentinel lymph nodes of breast cancer patients by 7T proton MR spectroscopy. J Magn Reson Imaging 2011; 35:387-92. [DOI: 10.1002/jmri.22820] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 08/26/2011] [Indexed: 12/14/2022] Open
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Korteweg MA, Zwanenburg JJM, Hoogduin JM, van den Bosch MAAJ, van Diest PJ, van Hillegersberg R, Eijkemans MJC, Mali WPTM, Luijten PR, Veldhuis WB. Dissected sentinel lymph nodes of breast cancer patients: characterization with high-spatial-resolution 7-T MR imaging. Radiology 2011; 261:127-35. [PMID: 21673230 DOI: 10.1148/radiol.11103535] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
PURPOSE To investigate the association of 7-T magnetic resonance (MR) imaging characteristics with metastatic nodal invasion, determined with histopathologic assessment in dissected sentinel lymph nodes of breast cancer patients. MATERIALS AND METHODS Institutional review board approval and informed consent were obtained. From November 2008 to July 2010, 114 dissected lymph nodes from 33 women (mean age, 57 years; range, 31-80 years) with breast cancer were included. For morphological analysis, three-dimensional (3D) T1-weighted fat-suppressed fast field- (gradient-) echo (isotropic resolution, 180 μm) MR was performed; 3D nodal dimensions, maximum cortical thickness, and presence of fatty hilum were noted. For quantitative parametric analysis, two-dimensional T1-weighted and 3D T2-, T2*-, and diffusion-weighted images were acquired. Statistical analysis included generalized estimating equations (GEEs), forward and backward stepwise regression analyses, and calculation of positive predictive value (PPV) and negative predictive value (NPV). RESULTS Of 114 nodes, 26 (23%) were malignant. Morphological criteria showed weak discriminatory power: A fatty center was absent in 35% of malignant nodes and 30% of benign nodes (P = .9). Nodal volume and length-width ratio were not significantly different (P = .11 and .75, respectively). Cortical thickness (threshold level, 3 mm; P = .02) showed 91% NPV for malignancy and 95% NPV for presence of macrometastases. Quantitative parametric analyses showed comparable mean T1, T2, and T2* relaxation time constants and apparent diffusion coefficient for metastatic and benign nodes: 991 msec, 30 msec, and 18 msec and 0.17 mm²/sec versus 1035 msec (P = .14), 31 msec (P = .001; not significant after GEE), and 15 msec (P = .002) and 0.20 mm²/sec (P = .38), respectively. Mean T2* alone offered an additive discriminatory effect for identification of metastatic nodes. Consistent with the notion of pannodal changes accompanying tumor infiltration, mean T2* differed significantly even if only micrometastases were present. The interindividual differences were small, precluding easy clinical implementation. CONCLUSION Morphological criteria showed poor discriminatory power, even with very-high-spatial-resolution imaging. T2* quantification allowed identification of metastatic nodal invasion.
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Affiliation(s)
- Mies A Korteweg
- Department of Radiology, University Medical Center Utrecht, HP.E01.102, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
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