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Sandoval Karamian AG, Yang QZ, Tam LT, Rao VL, Tong E, Yeom KW. Intracranial Hemorrhage in Term and Late-Preterm Neonates: An Institutional Perspective. AJNR Am J Neuroradiol 2022; 43:1494-1499. [PMID: 36137666 PMCID: PMC9575529 DOI: 10.3174/ajnr.a7642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 07/27/2022] [Indexed: 01/26/2023]
Abstract
BACKGROUND AND PURPOSE Distribution of intracranial hemorrhage in term and late-preterm neonates is relatively unexplored. This descriptive study examines the MR imaging-detectable spectrum of intracranial hemorrhage in this population and potential risk factors. MATERIALS AND METHODS Prevalence and distribution of intracranial hemorrhage in consecutive term/late-preterm neonates who underwent brain MR imaging between January 2011 to August 2018 were assessed. MRIs were analyzed to determine intracranial hemorrhage distribution (intraventricular, subarachnoid, subdural, intraparenchymal, and subpial/leptomeningeal), and chart review was performed for potential clinical risk factors. RESULTS Of 725 term/late-preterm neonates who underwent brain MR imaging, intracranial hemorrhage occurred in 63 (9%). Fifty-two (83%) had multicompartment intracranial hemorrhage. Intraventricular and subdural were the most common hemorrhage locations, found in 41 (65%) and 39 (62%) neonates, respectively. Intraparenchymal hemorrhage occurred in 33 (52%); subpial, in 19 (30%); subarachnoid, in 12 (19%); and epidural, in 2 (3%) neonates. Twenty infants (32%) were delivered via cesarean delivery, and 5 (8%), via instrumented delivery. Cortical vein thromboses were present in 34 (54%); periventricular or medullary vein thromboses, in 37 (59%); and cerebral venous sinus thrombosis, in 5 (8%). Thirty-seven (59%) had elevated markers of coagulopathy (international normalized ratio > 1.2, fibrinogen level < 234), 9 (14%) had a clinically meaningful elevation in the international normalized ratio (>1.4), and 3 (5%) had a clinically meaningful decrease in the fibrinogen level (<150). Three (5%) neonates had thrombocytopenia (platelet count < 100 × 103/μL). CONCLUSIONS While relatively infrequent, there was a wide distribution of intracranial hemorrhage in term and late-preterm infants; intraventricular and subdural hemorrhages were the most common types. We report a high prevalence of venous congestion or thromboses accompanying neonatal intracranial hemorrhage.
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Affiliation(s)
- A G Sandoval Karamian
- From the Division of Child Neurology (A.G.S.K.), University of Utah, Salt Lake City, Utah
| | - Q-Z Yang
- Division of Child Neurology (Q.-Z.Y.), University of North Carolina, Chapel Hill, North Carolina
| | - L T Tam
- Stanford University School of Medicine (L.T.T., V.L.R.), Palo Alto, California
| | - V L Rao
- Stanford University School of Medicine (L.T.T., V.L.R.), Palo Alto, California
| | - E Tong
- Department of Radiology (E.T., K.W.Y.), Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
| | - K W Yeom
- Department of Radiology (E.T., K.W.Y.), Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
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Zhang M, Tam L, Wright J, Mohammadzadeh M, Han M, Chen E, Wagner M, Nemalka J, Lai H, Eghbal A, Ho CY, Lober RM, Cheshier SH, Vitanza NA, Grant GA, Prolo LM, Yeom KW, Jaju A. Radiomics Can Distinguish Pediatric Supratentorial Embryonal Tumors, High-Grade Gliomas, and Ependymomas. AJNR Am J Neuroradiol 2022; 43:603-610. [PMID: 35361575 PMCID: PMC8993189 DOI: 10.3174/ajnr.a7481] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 01/25/2022] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Pediatric supratentorial tumors such as embryonal tumors, high-grade gliomas, and ependymomas are difficult to distinguish by histopathology and imaging because of overlapping features. We applied machine learning to uncover MR imaging-based radiomics phenotypes that can differentiate these tumor types. MATERIALS AND METHODS Our retrospective cohort of 231 patients from 7 participating institutions had 50 embryonal tumors, 127 high-grade gliomas, and 54 ependymomas. For each tumor volume, we extracted 900 Image Biomarker Standardization Initiative-based PyRadiomics features from T2-weighted and gadolinium-enhanced T1-weighted images. A reduced feature set was obtained by sparse regression analysis and was used as input for 6 candidate classifier models. Training and test sets were randomly allocated from the total cohort in a 75:25 ratio. RESULTS The final classifier model for embryonal tumor-versus-high-grade gliomas identified 23 features with an area under the curve of 0.98; the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 0.85, 0.91, 0.79, 0.94, and 0.89, respectively. The classifier for embryonal tumor-versus-ependymomas identified 4 features with an area under the curve of 0.82; the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 0.93, 0.69, 0.76, 0.90, and 0.81, respectively. The classifier for high-grade gliomas-versus-ependymomas identified 35 features with an area under the curve of 0.96; the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 0.82, 0.94, 0.82, 0.94, and 0.91, respectively. CONCLUSIONS In this multi-institutional study, we identified distinct radiomic phenotypes that distinguish pediatric supratentorial tumors, high-grade gliomas, and ependymomas with high accuracy. Incorporation of this technique in diagnostic algorithms can improve diagnosis, risk stratification, and treatment planning.
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Affiliation(s)
- M Zhang
- From the Departments of Neurosurgery (M.Z.)
| | - L Tam
- Stanford University School of Medicine (L.T.), Stanford, California
| | - J Wright
- Department of Radiology (J.W.).,Department of Radiology (J.W.), Harborview Medical Center, Seattle, Washington
| | - M Mohammadzadeh
- Department of Radiology (M.M.), Tehran University of Medical Sciences, Tehran, Iran
| | - M Han
- Department of Pediatrics (M.H.), Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania
| | - E Chen
- Departments of Clinical Radiology & Imaging Sciences (E.C., C.Y.H.), Riley Children's Hospital, Indiana University, Indianapolis, Indiana
| | - M Wagner
- Department of Diagnostic Imaging (M.W.), The Hospital for Sick Children, Ontario, Canada
| | - J Nemalka
- Division of Pediatric Neurosurgery (J.N., S.H.C.), Department of Neurosurgery, Huntsman Cancer Institute, Intermountain Healthcare Primary Children's Hospital, University of Utah School of Medicine, Salt Lake City, Utah
| | - H Lai
- Department of Radiology (H.L., A.E.), CHOC Children's Hospital of Orange County California, University of California, Irvine, California
| | - A Eghbal
- Department of Radiology (H.L., A.E.), CHOC Children's Hospital of Orange County California, University of California, Irvine, California
| | - C Y Ho
- Departments of Clinical Radiology & Imaging Sciences (E.C., C.Y.H.), Riley Children's Hospital, Indiana University, Indianapolis, Indiana
| | - R M Lober
- Division of Neurosurgery (R.M.L.), Dayton Children's Hospital, Dayton, Ohio; Department of Pediatrics, Wright State University Boonshoft School of Medicine, Dayton, Ohio
| | - S H Cheshier
- Division of Pediatric Neurosurgery (J.N., S.H.C.), Department of Neurosurgery, Huntsman Cancer Institute, Intermountain Healthcare Primary Children's Hospital, University of Utah School of Medicine, Salt Lake City, Utah
| | - N A Vitanza
- Division of Pediatric Hematology/Oncology (N.A.V.), Department of Pediatrics, Seattle Children's Hospital, Seattle, Washington
| | - G A Grant
- Neurosurgery (G.A.G., L.M.P.), Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
| | - L M Prolo
- Neurosurgery (G.A.G., L.M.P.), Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
| | - K W Yeom
- Departments of Radiology (K.W.Y.)
| | - A Jaju
- Department of Medical Imaging (A.J.), Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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Zhang M, Wong SW, Lummus S, Han M, Radmanesh A, Ahmadian SS, Prolo LM, Lai H, Eghbal A, Oztekin O, Cheshier SH, Fisher PG, Ho CY, Vogel H, Vitanza NA, Lober RM, Grant GA, Jaju A, Yeom KW. Radiomic Phenotypes Distinguish Atypical Teratoid/Rhabdoid Tumors from Medulloblastoma. AJNR Am J Neuroradiol 2021; 42:1702-1708. [PMID: 34266866 DOI: 10.3174/ajnr.a7200] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 04/05/2021] [Indexed: 01/06/2023]
Abstract
BACKGROUND AND PURPOSE Atypical teratoid/rhabdoid tumors and medulloblastomas have similar imaging and histologic features but distinctly different outcomes. We hypothesized that they could be distinguished by MR imaging-based radiomic phenotypes. MATERIALS AND METHODS We retrospectively assembled T2-weighted and gadolinium-enhanced T1-weighted images of 48 posterior fossa atypical teratoid/rhabdoid tumors and 96 match-paired medulloblastomas from 7 institutions. Using a holdout test set, we measured the performance of 6 candidate classifier models using 6 imaging features derived by sparse regression of 900 T2WI and 900 T1WI Imaging Biomarker Standardization Initiative-based radiomics features. RESULTS From the originally extracted 1800 total Imaging Biomarker Standardization Initiative-based features, sparse regression consistently reduced the feature set to 1 from T1WI and 5 from T2WI. Among classifier models, logistic regression performed with the highest AUC of 0.86, with sensitivity, specificity, accuracy, and F1 scores of 0.80, 0.82, 0.81, and 0.85, respectively. The top 3 important Imaging Biomarker Standardization Initiative features, by decreasing order of relative contribution, included voxel intensity at the 90th percentile, inverse difference moment normalized, and kurtosis-all from T2WI. CONCLUSIONS Six quantitative signatures of image intensity, texture, and morphology distinguish atypical teratoid/rhabdoid tumors from medulloblastomas with high prediction performance across different machine learning strategies. Use of this technique for preoperative diagnosis of atypical teratoid/rhabdoid tumors could significantly inform therapeutic strategies and patient care discussions.
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Affiliation(s)
- M Zhang
- From the Departments of Neurosurgery (M.Z.)
| | - S W Wong
- Department of Statistics (S.W.W.), Stanford University, Stanford, California
| | - S Lummus
- Department of Physiology and Nutrition (S.L.), University of Colorado, Colorado Springs, Colorado
| | - M Han
- Department of Pediatrics (M.H.), Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania
| | - A Radmanesh
- Department of Radiology (A.R.), New York University Grossman School of Medicine, New York, New York
| | - S S Ahmadian
- Pathology (S.S.A., H.V.), Stanford Medical Center, Stanford University, Stanford, California
| | - L M Prolo
- Departments of Neurosurgery (L.M.P., G.A.G.)
| | - H Lai
- Department of Radiology (H.L., A.E.), Children's Hospital of Orange County, Orange, California and University of California, Irvine, Irvine, California
| | - A Eghbal
- Department of Radiology (H.L., A.E.), Children's Hospital of Orange County, Orange, California and University of California, Irvine, Irvine, California
| | - O Oztekin
- Department of Neuroradiology (O.O.), Cigli Education and Research Hospital, Bakircay University, Izmir, Turkey.,Department of Neuroradiology (O.O.), Tepecik Education and Research Hospital, Health Science University, Izmir, Turkey
| | - S H Cheshier
- Division of Pediatric Neurosurgery (S.H.C.), Department of Neurosurgery, Huntsman Cancer Institute, Intermountain Healthcare Primary Children's Hospital, University of Utah School of Medicine, Salt Lake City, Utah
| | | | - C Y Ho
- Departments of Clinical Radiology & Imaging Sciences (C.Y.H.), Riley Children's Hospital, Indiana University, Indianapolis, Indiana
| | - H Vogel
- Pathology (S.S.A., H.V.), Stanford Medical Center, Stanford University, Stanford, California
| | - N A Vitanza
- Division of Pediatric Hematology/Oncology (N.A.V.), Department of Pediatrics, Seattle Children's Hospital, Seattle, Washington
| | - R M Lober
- Division of Neurosurgery (R.M.L.), Department of Pediatrics, Wright State University Boonshoft School of Medicine, Dayton Children's Hospital, Dayton, Ohio
| | - G A Grant
- Departments of Neurosurgery (L.M.P., G.A.G.)
| | - A Jaju
- Department of Medical Imaging (A.J.), Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - K W Yeom
- Radiology (K.W.Y.), Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
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Wagner MW, Hainc N, Khalvati F, Namdar K, Figueiredo L, Sheng M, Laughlin S, Shroff MM, Bouffet E, Tabori U, Hawkins C, Yeom KW, Ertl-Wagner BB. Radiomics of Pediatric Low-Grade Gliomas: Toward a Pretherapeutic Differentiation of BRAF-Mutated and BRAF-Fused Tumors. AJNR Am J Neuroradiol 2021; 42:759-765. [PMID: 33574103 DOI: 10.3174/ajnr.a6998] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/23/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND PURPOSE B-Raf proto-oncogene, serine/threonine kinase (BRAF) status has important implications for prognosis and therapy of pediatric low-grade gliomas. Currently, BRAF status classification relies on biopsy. Our aim was to train and validate a radiomics approach to predict BRAF fusion and BRAF V600E mutation. MATERIALS AND METHODS In this bi-institutional retrospective study, FLAIR MR imaging datasets of 115 pediatric patients with low-grade gliomas from 2 children's hospitals acquired between January 2009 and January 2016 were included and analyzed. Radiomics features were extracted from tumor segmentations, and the predictive model was tested using independent training and testing datasets, with all available tumor types. The model was selected on the basis of a grid search on the number of trees, opting for the best split for a random forest. We used the area under the receiver operating characteristic curve to evaluate model performance. RESULTS The training cohort consisted of 94 pediatric patients with low-grade gliomas (mean age, 9.4 years; 45 boys), and the external validation cohort comprised 21 pediatric patients with low-grade gliomas (mean age, 8.37 years; 12 boys). A 4-fold cross-validation scheme predicted BRAF status with an area under the curve of 0.75 (SD, 0.12) (95% confidence interval, 0.62-0.89) on the internal validation cohort. By means of the optimal hyperparameters determined by 4-fold cross-validation, the area under the curve for the external validation was 0.85. Age and tumor location were significant predictors of BRAF status (P values = .04 and <.001, respectively). Sex was not a significant predictor (P value = .96). CONCLUSIONS Radiomics-based prediction of BRAF status in pediatric low-grade gliomas appears feasible in this bi-institutional exploratory study.
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Affiliation(s)
- M W Wagner
- From the Departments of Diagnostic Imaging (M.W.W., N.H., F.K., K.N., M.S., S.L., M.M.S., B.B.E.-W.)
| | - N Hainc
- From the Departments of Diagnostic Imaging (M.W.W., N.H., F.K., K.N., M.S., S.L., M.M.S., B.B.E.-W.).,Department of Neuroradiology (N.H.), Zurich University Hospital, University of Zurich, Zurich, Switzerland
| | - F Khalvati
- From the Departments of Diagnostic Imaging (M.W.W., N.H., F.K., K.N., M.S., S.L., M.M.S., B.B.E.-W.)
| | - K Namdar
- From the Departments of Diagnostic Imaging (M.W.W., N.H., F.K., K.N., M.S., S.L., M.M.S., B.B.E.-W.)
| | - L Figueiredo
- Division of Neuroradiology, Neurooncology (L.F., E.B., U.T.)
| | - M Sheng
- From the Departments of Diagnostic Imaging (M.W.W., N.H., F.K., K.N., M.S., S.L., M.M.S., B.B.E.-W.)
| | - S Laughlin
- From the Departments of Diagnostic Imaging (M.W.W., N.H., F.K., K.N., M.S., S.L., M.M.S., B.B.E.-W.)
| | - M M Shroff
- From the Departments of Diagnostic Imaging (M.W.W., N.H., F.K., K.N., M.S., S.L., M.M.S., B.B.E.-W.)
| | - E Bouffet
- Division of Neuroradiology, Neurooncology (L.F., E.B., U.T.)
| | - U Tabori
- Division of Neuroradiology, Neurooncology (L.F., E.B., U.T.)
| | - C Hawkins
- Paediatric Laboratory Medicine (C.H.), Division of Pathology, The Hospital for Sick Children and Department of Medical Imaging, University of Toronto, Ontario, Canada
| | - K W Yeom
- Department of Radiology (K.W.Y.), Stanford University School of Medicine, Lucile Packard Children's Hospital, Palo Alto, California
| | - B B Ertl-Wagner
- From the Departments of Diagnostic Imaging (M.W.W., N.H., F.K., K.N., M.S., S.L., M.M.S., B.B.E.-W.)
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5
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Quon JL, Bala W, Chen LC, Wright J, Kim LH, Han M, Shpanskaya K, Lee EH, Tong E, Iv M, Seekins J, Lungren MP, Braun KRM, Poussaint TY, Laughlin S, Taylor MD, Lober RM, Vogel H, Fisher PG, Grant GA, Ramaswamy V, Vitanza NA, Ho CY, Edwards MSB, Cheshier SH, Yeom KW. Deep Learning for Pediatric Posterior Fossa Tumor Detection and Classification: A Multi-Institutional Study. AJNR Am J Neuroradiol 2020; 41:1718-1725. [PMID: 32816765 PMCID: PMC7583118 DOI: 10.3174/ajnr.a6704] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 05/27/2020] [Indexed: 01/05/2023]
Abstract
BACKGROUND AND PURPOSE Posterior fossa tumors are the most common pediatric brain tumors. MR imaging is key to tumor detection, diagnosis, and therapy guidance. We sought to develop an MR imaging-based deep learning model for posterior fossa tumor detection and tumor pathology classification. MATERIALS AND METHODS The study cohort comprised 617 children (median age, 92 months; 56% males) from 5 pediatric institutions with posterior fossa tumors: diffuse midline glioma of the pons (n = 122), medulloblastoma (n = 272), pilocytic astrocytoma (n = 135), and ependymoma (n = 88). There were 199 controls. Tumor histology served as ground truth except for diffuse midline glioma of the pons, which was primarily diagnosed by MR imaging. A modified ResNeXt-50-32x4d architecture served as the backbone for a multitask classifier model, using T2-weighted MRIs as input to detect the presence of tumor and predict tumor class. Deep learning model performance was compared against that of 4 radiologists. RESULTS Model tumor detection accuracy exceeded an AUROC of 0.99 and was similar to that of 4 radiologists. Model tumor classification accuracy was 92% with an F1 score of 0.80. The model was most accurate at predicting diffuse midline glioma of the pons, followed by pilocytic astrocytoma and medulloblastoma. Ependymoma prediction was the least accurate. Tumor type classification accuracy and F1 score were higher than those of 2 of the 4 radiologists. CONCLUSIONS We present a multi-institutional deep learning model for pediatric posterior fossa tumor detection and classification with the potential to augment and improve the accuracy of radiologic diagnosis.
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Affiliation(s)
- J L Quon
- From the Departments of Neurosurgery (J.L.Q., G.A.G., M.S.B.E.)
| | - W Bala
- Department of Radiology (W.B., J.S., M.P.L., K.W.Y.)
| | | | - J Wright
- Department of Radiology (J.W.), Seattle Children's Hospital, University of Washington School of Medicine, Seattle, Washington
| | - L H Kim
- Stanford University School of Medicine (L.H.K., M.H., K.S.), Stanford, California
| | - M Han
- Stanford University School of Medicine (L.H.K., M.H., K.S.), Stanford, California
| | - K Shpanskaya
- Stanford University School of Medicine (L.H.K., M.H., K.S.), Stanford, California
| | - E H Lee
- Electrical Engineering (E.H.L.)
| | | | | | - J Seekins
- Department of Radiology (W.B., J.S., M.P.L., K.W.Y.)
| | - M P Lungren
- Department of Radiology (W.B., J.S., M.P.L., K.W.Y.)
| | - K R M Braun
- Departments of Clinical Radiology & Imaging Sciences (K.R.M.B., C.Y.H.), Riley Children's Hospital, Indiana University, Indianapolis, Indiana
| | - T Y Poussaint
- Departments of Radiology (T.Y.P.), Boston Children's Hospital, Boston, Massachusetts
| | - S Laughlin
- Departments of diagnostic Imaging (S.L.)
| | | | - R M Lober
- Department of Neurosurgery (R.M.L.), Dayton Children's Hospital, Wright State University Boonshoft School of Medicine, Dayton, Ohio
| | - H Vogel
- and Pathology (H.V.), Stanford University, Stanford, California
| | - P G Fisher
- Division of Child Neurology (P.G.F.), Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
| | - G A Grant
- From the Departments of Neurosurgery (J.L.Q., G.A.G., M.S.B.E.)
| | - V Ramaswamy
- and Haematology/Oncology (V.R.), The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - N A Vitanza
- Division of Pediatric Hematology/Oncology (N.A.V.), Department of Pediatrics, University of Washington, Seattle Children's Hospital, Seattle Washington.,Fred Hutchinson Cancer Research Center (N.A.V.), Seattle, Washington
| | - C Y Ho
- Departments of Clinical Radiology & Imaging Sciences (K.R.M.B., C.Y.H.), Riley Children's Hospital, Indiana University, Indianapolis, Indiana
| | - M S B Edwards
- From the Departments of Neurosurgery (J.L.Q., G.A.G., M.S.B.E.)
| | - S H Cheshier
- Departments of Neurosurgery (S.H.C.), University of Utah School of Medicine, Salt Lake City, Utah
| | - K W Yeom
- Department of Radiology (W.B., J.S., M.P.L., K.W.Y.)
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Jabarkheel R, Tong E, Lee EH, Cullen TM, Yousaf U, Loening AM, Taviani V, Iv M, Grant GA, Holdsworth SJ, Vasanawala SS, Yeom KW. Variable Refocusing Flip Angle Single-Shot Imaging for Sedation-Free Fast Brain MRI. AJNR Am J Neuroradiol 2020; 41:1256-1262. [PMID: 32586967 DOI: 10.3174/ajnr.a6616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 04/18/2020] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Conventional single-shot FSE commonly used for fast MRI may be suboptimal for brain evaluation due to poor image contrast, SNR, or image blurring. We investigated the clinical performance of variable refocusing flip angle single-shot FSE, a variation of single-shot FSE with lower radiofrequency energy deposition and potentially faster acquisition time, as an alternative approach to fast brain MR imaging. MATERIALS AND METHODS We retrospectively compared half-Fourier single-shot FSE with half- and full-Fourier variable refocusing flip angle single-shot FSE in 30 children. Three readers reviewed images for motion artifacts, image sharpness at the brain-fluid interface, and image sharpness/tissue contrast at gray-white differentiation on a modified 5-point Likert scale. Two readers also evaluated full-Fourier variable refocusing flip angle single-shot FSE against T2-FSE for brain lesion detectability in 38 children. RESULTS Variable refocusing flip angle single-shot FSE sequences showed more motion artifacts (P < .001). Variable refocusing flip angle single-shot FSE sequences scored higher regarding image sharpness at brain-fluid interfaces (P < .001) and gray-white differentiation (P < .001). Acquisition times for half- and full-Fourier variable refocusing flip angle single-shot FSE were faster than for single-shot FSE (P < .001) with a 53% and 47% reduction, respectively. Intermodality agreement between full-Fourier variable refocusing flip angle single-shot FSE and T2-FSE findings was near-perfect (κ = 0.90, κ = 0.95), with an 8% discordance rate for ground truth lesion detection. CONCLUSIONS Variable refocusing flip angle single-shot FSE achieved 2× faster scan times than single-shot FSE with improved image sharpness at brain-fluid interfaces and gray-white differentiation. Such improvements are likely attributed to a combination of improved contrast, spatial resolution, SNR, and reduced T2-decay associated with blurring. While variable refocusing flip angle single-shot FSE may be a useful alternative to single-shot FSE and, potentially, T2-FSE when faster scan times are desired, motion artifacts were more common in variable refocusing flip angle single-shot FSE, and, thus, they remain an important consideration before clinical implementation.
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Affiliation(s)
- R Jabarkheel
- From the Stanford University School of Medicine (R.J.)
| | - E Tong
- Departments of Radiology (E.T., A.M.L., V.T., M.I.)
| | - E H Lee
- Electrical Engineering (E.H.L.)
| | - T M Cullen
- Department of Radiology (T.M.C., U.Y., S.S.V., K.W.Y.), Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
| | - U Yousaf
- Department of Radiology (T.M.C., U.Y., S.S.V., K.W.Y.), Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
| | - A M Loening
- Departments of Radiology (E.T., A.M.L., V.T., M.I.)
| | - V Taviani
- Departments of Radiology (E.T., A.M.L., V.T., M.I.)
| | - M Iv
- Departments of Radiology (E.T., A.M.L., V.T., M.I.)
| | - G A Grant
- Neurosurgery (G.A.G.), Stanford University, Stanford, California
| | - S J Holdsworth
- Department of Anatomy and Medical Imaging and Centre for Brain Research (S.J.H.), Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - S S Vasanawala
- Department of Radiology (T.M.C., U.Y., S.S.V., K.W.Y.), Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
| | - K W Yeom
- Department of Radiology (T.M.C., U.Y., S.S.V., K.W.Y.), Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
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7
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Iv M, Zhou M, Shpanskaya K, Perreault S, Wang Z, Tranvinh E, Lanzman B, Vajapeyam S, Vitanza NA, Fisher PG, Cho YJ, Laughlin S, Ramaswamy V, Taylor MD, Cheshier SH, Grant GA, Young Poussaint T, Gevaert O, Yeom KW. MR Imaging-Based Radiomic Signatures of Distinct Molecular Subgroups of Medulloblastoma. AJNR Am J Neuroradiol 2018; 40:154-161. [PMID: 30523141 DOI: 10.3174/ajnr.a5899] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/06/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND PURPOSE Distinct molecular subgroups of pediatric medulloblastoma confer important differences in prognosis and therapy. Currently, tissue sampling is the only method to obtain information for classification. Our goal was to develop and validate radiomic and machine learning approaches for predicting molecular subgroups of pediatric medulloblastoma. MATERIALS AND METHODS In this multi-institutional retrospective study, we evaluated MR imaging datasets of 109 pediatric patients with medulloblastoma from 3 children's hospitals from January 2001 to January 2014. A computational framework was developed to extract MR imaging-based radiomic features from tumor segmentations, and we tested 2 predictive models: a double 10-fold cross-validation using a combined dataset consisting of all 3 patient cohorts and a 3-dataset cross-validation, in which training was performed on 2 cohorts and testing was performed on the third independent cohort. We used the Wilcoxon rank sum test for feature selection with assessment of area under the receiver operating characteristic curve to evaluate model performance. RESULTS Of 590 MR imaging-derived radiomic features, including intensity-based histograms, tumor edge-sharpness, Gabor features, and local area integral invariant features, extracted from imaging-derived tumor segmentations, tumor edge-sharpness was most useful for predicting sonic hedgehog and group 4 tumors. Receiver operating characteristic analysis revealed superior performance of the double 10-fold cross-validation model for predicting sonic hedgehog, group 3, and group 4 tumors when using combined T1- and T2-weighted images (area under the curve = 0.79, 0.70, and 0.83, respectively). With the independent 3-dataset cross-validation strategy, select radiomic features were predictive of sonic hedgehog (area under the curve = 0.70-0.73) and group 4 (area under the curve = 0.76-0.80) medulloblastoma. CONCLUSIONS This study provides proof-of-concept results for the application of radiomic and machine learning approaches to a multi-institutional dataset for the prediction of medulloblastoma subgroups.
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Affiliation(s)
- M Iv
- From the Department of Radiology (M.I., M.Z., K.S., E.T., B.L., K.W.Y.)
| | - M Zhou
- From the Department of Radiology (M.I., M.Z., K.S., E.T., B.L., K.W.Y.).,Stanford Center for Biomedical Informatics (M.Z., O.G., Z.W.)
| | - K Shpanskaya
- From the Department of Radiology (M.I., M.Z., K.S., E.T., B.L., K.W.Y.)
| | - S Perreault
- Department of Pediatrics (S.P.), Pediatric Neurology, Centre Hospitalier Universitaire Sainte Justine, University of Montréal, Montreal, Quebec, Canada
| | - Z Wang
- Stanford Center for Biomedical Informatics (M.Z., O.G., Z.W.)
| | - E Tranvinh
- From the Department of Radiology (M.I., M.Z., K.S., E.T., B.L., K.W.Y.)
| | - B Lanzman
- From the Department of Radiology (M.I., M.Z., K.S., E.T., B.L., K.W.Y.)
| | - S Vajapeyam
- Department of Radiology (S.V., T.Y.P.), Boston Children's Hospital, Harvard University, Boston, Massachusetts
| | - N A Vitanza
- Department Pediatrics Hematology-Oncology (N.A.V.), Seattle Children's Hospital, University of Washington, Seattle, Washington
| | - P G Fisher
- Department of Pediatrics (P.G.F.), Pediatric Neurology
| | - Y J Cho
- Department of Pediatrics (Y.J.C.), Pediatric Neurology, Oregon Health & Science University, Portland, Oregon
| | - S Laughlin
- Departments of Radiology, Neuro-Oncology, and Neurosurgery (S.L., V.R., M.D.T.), Hospital for Sick Children, Toronto, Ontario, Canada
| | - V Ramaswamy
- Departments of Radiology, Neuro-Oncology, and Neurosurgery (S.L., V.R., M.D.T.), Hospital for Sick Children, Toronto, Ontario, Canada
| | - M D Taylor
- Departments of Radiology, Neuro-Oncology, and Neurosurgery (S.L., V.R., M.D.T.), Hospital for Sick Children, Toronto, Ontario, Canada
| | - S H Cheshier
- Department of Neurosurgery (S.H.C.), Pediatric Neurosurgery, University of Utah, Salt Lake City, Utah
| | - G A Grant
- Department of Neurosurgery (G.A.G.), Pediatric Neurosurgery, Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
| | - T Young Poussaint
- Department of Radiology (S.V., T.Y.P.), Boston Children's Hospital, Harvard University, Boston, Massachusetts
| | - O Gevaert
- Stanford Center for Biomedical Informatics (M.Z., O.G., Z.W.)
| | - K W Yeom
- From the Department of Radiology (M.I., M.Z., K.S., E.T., B.L., K.W.Y.) .,Department of Radiology (K.W.Y.), Artificial Intelligence in Medicine and Imaging, Stanford University, Stanford, California
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8
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Santoro JD, Forkert ND, Yang QZ, Pavitt S, MacEachern SJ, Moseley ME, Yeom KW. Brain Diffusion Abnormalities in Children with Tension-Type and Migraine-Type Headaches. AJNR Am J Neuroradiol 2018; 39:935-941. [PMID: 29545251 DOI: 10.3174/ajnr.a5582] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 01/01/2018] [Indexed: 01/03/2023]
Abstract
BACKGROUND AND PURPOSE Tension-type and migraine-type headaches are the most common chronic paroxysmal disorders of childhood. The goal of this study was to compare regional cerebral volumes and diffusion in tension-type and migraine-type headaches against published controls. MATERIALS AND METHODS Patients evaluated for tension-type or migraine-type headache without aura from May 2014 to July 2016 in a single center were retrospectively reviewed. Thirty-two patients with tension-type headache and 23 with migraine-type headache at an average of 4 months after diagnosis were enrolled. All patients underwent DWI at 3T before the start of pharmacotherapy. Using atlas-based DWI analysis, we determined regional volumetric and diffusion properties in the cerebral cortex, thalamus, caudate, putamen, globus pallidus, hippocampus, amygdala, nucleus accumbens, brain stem, and cerebral white matter. Multivariate analysis of covariance was used to test for differences between controls and patients with tension-type and migraine-type headaches. RESULTS There were no significant differences in regional brain volumes between the groups. Patients with tension-type and migraine-type headaches showed significantly increased ADC in the hippocampus and brain stem compared with controls. Additionally, only patients with migraine-type headache showed significantly increased ADC in the thalamus and a trend toward increased ADC in the amygdala compared with controls. CONCLUSIONS This study identifies early cerebral diffusion changes in patients with tension-type and migraine-type headaches compared with controls. The hypothesized mechanisms of nociception in migraine-type and tension-type headaches may explain the findings as a precursor to structural changes seen in adult patients with chronic headache.
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Affiliation(s)
- J D Santoro
- From the Department of Neurology (J.D.S., Q.-Z.Y., S.P.), Division of Child Neurology
| | | | - Q-Z Yang
- From the Department of Neurology (J.D.S., Q.-Z.Y., S.P.), Division of Child Neurology
| | - S Pavitt
- From the Department of Neurology (J.D.S., Q.-Z.Y., S.P.), Division of Child Neurology
| | - S J MacEachern
- Pediatrics (S.J.M.), Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - M E Moseley
- Department of Radiology (M.E.M.), Stanford University School of Medicine, Stanford, California
| | - K W Yeom
- Department of Radiology (K.W.Y.), Lucile Packard Children's Hospital, Stanford University, Stanford, California.
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9
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Zhou M, Scott J, Chaudhury B, Hall L, Goldgof D, Yeom KW, Iv M, Ou Y, Kalpathy-Cramer J, Napel S, Gillies R, Gevaert O, Gatenby R. Radiomics in Brain Tumor: Image Assessment, Quantitative Feature Descriptors, and Machine-Learning Approaches. AJNR Am J Neuroradiol 2018; 39:208-216. [PMID: 28982791 PMCID: PMC5812810 DOI: 10.3174/ajnr.a5391] [Citation(s) in RCA: 190] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Radiomics describes a broad set of computational methods that extract quantitative features from radiographic images. The resulting features can be used to inform imaging diagnosis, prognosis, and therapy response in oncology. However, major challenges remain for methodologic developments to optimize feature extraction and provide rapid information flow in clinical settings. Equally important, to be clinically useful, predictive radiomic properties must be clearly linked to meaningful biologic characteristics and qualitative imaging properties familiar to radiologists. Here we use a cross-disciplinary approach to highlight studies in radiomics. We review brain tumor radiologic studies (eg, imaging interpretation) through computational models (eg, computer vision and machine learning) that provide novel clinical insights. We outline current quantitative image feature extraction and prediction strategies with different levels of available clinical classes for supporting clinical decision-making. We further discuss machine-learning challenges and data opportunities to advance radiomic studies.
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Affiliation(s)
- M Zhou
- From the Stanford Center for Biomedical Informatic Research (M.Z., O.G.)
| | - J Scott
- Department of Radiology (J.S., B.C., S.N., R. Gillies, R. Gatenby), Moffitt Cancer Research Center, Tampa, Florida
| | - B Chaudhury
- Department of Radiology (J.S., B.C., S.N., R. Gillies, R. Gatenby), Moffitt Cancer Research Center, Tampa, Florida
| | - L Hall
- Department of Computer Science and Engineering (L.H., D.G.), University of South Florida, Tampa, Florida
| | - D Goldgof
- Department of Computer Science and Engineering (L.H., D.G.), University of South Florida, Tampa, Florida
| | - K W Yeom
- Department of Radiology (K.W.Y., M.I.), Stanford University, Stanford, California
| | - M Iv
- Department of Radiology (K.W.Y., M.I.), Stanford University, Stanford, California
| | - Y Ou
- Department of Radiology (Y.O., J.K.-C.), Massachusetts General Hospital, Boston, Massachusetts
| | - J Kalpathy-Cramer
- Department of Radiology (Y.O., J.K.-C.), Massachusetts General Hospital, Boston, Massachusetts
| | - S Napel
- Department of Radiology (J.S., B.C., S.N., R. Gillies, R. Gatenby), Moffitt Cancer Research Center, Tampa, Florida
| | - R Gillies
- Department of Radiology (J.S., B.C., S.N., R. Gillies, R. Gatenby), Moffitt Cancer Research Center, Tampa, Florida
| | - O Gevaert
- From the Stanford Center for Biomedical Informatic Research (M.Z., O.G.)
| | - R Gatenby
- Department of Radiology (J.S., B.C., S.N., R. Gillies, R. Gatenby), Moffitt Cancer Research Center, Tampa, Florida
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10
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Forkert ND, Li MD, Lober RM, Yeom KW. Gray Matter Growth Is Accompanied by Increasing Blood Flow and Decreasing Apparent Diffusion Coefficient during Childhood. AJNR Am J Neuroradiol 2016; 37:1738-44. [PMID: 27102314 DOI: 10.3174/ajnr.a4772] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 02/08/2016] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND PURPOSE Normal values of gray matter volume, cerebral blood flow, and water diffusion have not been established for healthy children. We sought to determine reference values for age-dependent changes of these parameters in healthy children. MATERIALS AND METHODS We retrospectively reviewed MR imaging data from 100 healthy children. Using an atlas-based approach, age-related normal values for regional CBF, apparent diffusion coefficient, and volume were determined for the cerebral cortex, hippocampus, thalamus, caudate, putamen, globus pallidus, amygdala, and nucleus accumbens. RESULTS All gray matter structures grew rapidly before the age of 10 years and then plateaued or slightly declined thereafter. The ADC of all structures decreased with age, with the most rapid changes occurring prior to the age of 5 years. With the exception of the globus pallidus, CBF increased rather linearly with age. CONCLUSIONS Normal brain gray matter is characterized by rapid early volume growth and increasing CBF with concomitantly decreasing ADC. The extracted reference data that combine CBF and ADC parameters during brain growth may provide a useful resource when assessing pathologic changes in children.
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Affiliation(s)
- N D Forkert
- From the Department of Radiology and Hotchkiss Brain Institute (N.D.F.), University of Calgary, Calgary, Alberta, Canada
| | - M D Li
- Department of Radiology (M.D.L., K.W.Y.), Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
| | - R M Lober
- Department of Neurosurgery (R.M.L.), Dayton Children's Hospital, Boonshoft School of Medicine, Dayton, Ohio
| | - K W Yeom
- Department of Radiology (M.D.L., K.W.Y.), Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
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11
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Liu TT, Achrol AS, Mitchell LA, Du WA, Loya JJ, Rodriguez SA, Feroze A, Westbroek EM, Yeom KW, Stuart JM, Chang SD, Harsh GR, Rubin DL. Computational Identification of Tumor Anatomic Location Associated with Survival in 2 Large Cohorts of Human Primary Glioblastomas. AJNR Am J Neuroradiol 2016; 37:621-8. [PMID: 26744442 DOI: 10.3174/ajnr.a4631] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/02/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND PURPOSE Tumor location has been shown to be a significant prognostic factor in patients with glioblastoma. The purpose of this study was to characterize glioblastoma lesions by identifying MR imaging voxel-based tumor location features that are associated with tumor molecular profiles, patient characteristics, and clinical outcomes. MATERIALS AND METHODS Preoperative T1 anatomic MR images of 384 patients with glioblastomas were obtained from 2 independent cohorts (n = 253 from the Stanford University Medical Center for training and n = 131 from The Cancer Genome Atlas for validation). An automated computational image-analysis pipeline was developed to determine the anatomic locations of tumor in each patient. Voxel-based differences in tumor location between good (overall survival of >17 months) and poor (overall survival of <11 months) survival groups identified in the training cohort were used to classify patients in The Cancer Genome Atlas cohort into 2 brain-location groups, for which clinical features, messenger RNA expression, and copy number changes were compared to elucidate the biologic basis of tumors located in different brain regions. RESULTS Tumors in the right occipitotemporal periventricular white matter were significantly associated with poor survival in both training and test cohorts (both, log-rank P < .05) and had larger tumor volume compared with tumors in other locations. Tumors in the right periatrial location were associated with hypoxia pathway enrichment and PDGFRA amplification, making them potential targets for subgroup-specific therapies. CONCLUSIONS Voxel-based location in glioblastoma is associated with patient outcome and may have a potential role for guiding personalized treatment.
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Affiliation(s)
- T T Liu
- From the Stanford Center for Biomedical Informatics Research and Biomedical Informatics Training Program (T.T.L., D.L.R.) Department of Radiology (T.T.L., L.A.M., W.A.D., K.W.Y., D.L.R.)
| | - A S Achrol
- Stanford Institute for Neuro-Innovation and Translational Neurosciences (A.S.A.) Institute for Stem Cell Biology and Regenerative Medicine (A.S.A.) Department of Neurosurgery (A.S.A., J.J.L., S.A.R., E.M.W., S.D.C., G.R.H.), Stanford University School of Medicine, Stanford, California
| | - L A Mitchell
- Department of Radiology (T.T.L., L.A.M., W.A.D., K.W.Y., D.L.R.)
| | - W A Du
- Department of Radiology (T.T.L., L.A.M., W.A.D., K.W.Y., D.L.R.)
| | - J J Loya
- Department of Neurosurgery (A.S.A., J.J.L., S.A.R., E.M.W., S.D.C., G.R.H.), Stanford University School of Medicine, Stanford, California
| | - S A Rodriguez
- Department of Neurosurgery (A.S.A., J.J.L., S.A.R., E.M.W., S.D.C., G.R.H.), Stanford University School of Medicine, Stanford, California
| | - A Feroze
- Department of Neurological Surgery (A.F.), University of Washington School of Medicine, Seattle, Washington
| | - E M Westbroek
- Department of Neurosurgery (A.S.A., J.J.L., S.A.R., E.M.W., S.D.C., G.R.H.), Stanford University School of Medicine, Stanford, California
| | - K W Yeom
- Department of Radiology (T.T.L., L.A.M., W.A.D., K.W.Y., D.L.R.)
| | - J M Stuart
- Biomolecular Engineering (J.M.S.), University of California Santa Cruz, Santa Cruz, California
| | - S D Chang
- Department of Neurosurgery (A.S.A., J.J.L., S.A.R., E.M.W., S.D.C., G.R.H.), Stanford University School of Medicine, Stanford, California
| | - G R Harsh
- Department of Neurosurgery (A.S.A., J.J.L., S.A.R., E.M.W., S.D.C., G.R.H.), Stanford University School of Medicine, Stanford, California
| | - D L Rubin
- From the Stanford Center for Biomedical Informatics Research and Biomedical Informatics Training Program (T.T.L., D.L.R.) Department of Radiology (T.T.L., L.A.M., W.A.D., K.W.Y., D.L.R.)
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12
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Abstract
BACKGROUND AND PURPOSE Reduced cerebral perfusion has been observed with elevated intracranial pressure. We hypothesized that arterial spin-labeled CBF can be used as a marker for symptomatic hydrocephalus. MATERIALS AND METHODS We compared baseline arterial spin-labeled CBF in 19 children (median age, 6.5 years; range, 1-17 years) with new posterior fossa brain tumors and clinical signs of intracranial hypertension with arterial spin-labeled CBF in 16 age-matched controls and 4 patients with posterior fossa tumors without ventriculomegaly or signs of intracranial hypertension. Measurements were recorded in the cerebrum at the vertex, deep gray nuclei, and periventricular white matter and were assessed for a relationship to ventricular size. In 16 symptomatic patients, we compared cerebral perfusion before and after alleviation of hydrocephalus. RESULTS Patients with uncompensated hydrocephalus had lower arterial spin-labeled CBF than healthy controls for all brain regions interrogated (P < .001). No perfusion difference was seen between asymptomatic patients with posterior fossa tumors and healthy controls (P = 1.000). The median arterial spin-labeled CBF increased after alleviation of obstructive hydrocephalus (P < .002). The distance between the frontal horns inversely correlated with arterial spin-labeled CBF of the cerebrum (P = .036) but not the putamen (P = .156), thalamus (P = .111), or periventricular white matter (P = .121). CONCLUSIONS Arterial spin-labeled-CBF was reduced in children with uncompensated hydrocephalus and restored after its alleviation. Arterial spin-labeled-CBF perfusion MR imaging may serve a future role in the neurosurgical evaluation of hydrocephalus, as a potential noninvasive method to follow changes of intracranial pressure with time.
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Affiliation(s)
- K W Yeom
- From the Departments of Radiology (K.W.Y.)
| | - R M Lober
- Neurosurgery (R.M.L., A.A., S.H.C., M.S.B.E.)
| | - A Alexander
- Neurosurgery (R.M.L., A.A., S.H.C., M.S.B.E.)
| | - S H Cheshier
- Neurosurgery (R.M.L., A.A., S.H.C., M.S.B.E.)Division of Pediatric Neurosurgery (S.H.C., M.S.B.E.), Lucile Packard Children's Hospital at Stanford University, Palo Alto, California
| | - M S B Edwards
- Neurosurgery (R.M.L., A.A., S.H.C., M.S.B.E.)Division of Pediatric Neurosurgery (S.H.C., M.S.B.E.), Lucile Packard Children's Hospital at Stanford University, Palo Alto, California
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13
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Perreault S, Ramaswamy V, Achrol AS, Chao K, Liu TT, Shih D, Remke M, Schubert S, Bouffet E, Fisher PG, Partap S, Vogel H, Taylor MD, Cho YJ, Yeom KW. MRI surrogates for molecular subgroups of medulloblastoma. AJNR Am J Neuroradiol 2014; 35:1263-9. [PMID: 24831600 DOI: 10.3174/ajnr.a3990] [Citation(s) in RCA: 186] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND AND PURPOSE Recently identified molecular subgroups of medulloblastoma have shown potential for improved risk stratification. We hypothesized that distinct MR imaging features can predict these subgroups. MATERIALS AND METHODS All patients with a diagnosis of medulloblastoma at one institution, with both pretherapy MR imaging and surgical tissue, served as the discovery cohort (n = 47). MR imaging features were assessed by 3 blinded neuroradiologists. NanoString-based assay of tumor tissues was conducted to classify the tumors into the 4 established molecular subgroups (wingless, sonic hedgehog, group 3, and group 4). A second pediatric medulloblastoma cohort (n = 52) from an independent institution was used for validation of the MR imaging features predictive of the molecular subtypes. RESULTS Logistic regression analysis within the discovery cohort revealed tumor location (P < .001) and enhancement pattern (P = .001) to be significant predictors of medulloblastoma subgroups. Stereospecific computational analyses confirmed that group 3 and 4 tumors predominated within the midline fourth ventricle (100%, P = .007), wingless tumors were localized to the cerebellar peduncle/cerebellopontine angle cistern with a positive predictive value of 100% (95% CI, 30%-100%), and sonic hedgehog tumors arose in the cerebellar hemispheres with a positive predictive value of 100% (95% CI, 59%-100%). Midline group 4 tumors presented with minimal/no enhancement with a positive predictive value of 91% (95% CI, 59%-98%). When we used the MR imaging feature-based regression model, 66% of medulloblastomas were correctly predicted in the discovery cohort, and 65%, in the validation cohort. CONCLUSIONS Tumor location and enhancement pattern were predictive of molecular subgroups of pediatric medulloblastoma and may potentially serve as a surrogate for genomic testing.
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Affiliation(s)
- S Perreault
- From the Department of Neurology (S. Perreault, S.S., P.G.F., S. Partap, Y.J.C.), Division of Child NeurologyDivision of Child Neurology (S. Perreault), Centre Hospitalier Universitaire Sainte-Justine, Montreal, Quebec, Canada
| | - V Ramaswamy
- Division of Neurosurgery (V.R., D.S., M.R., M.D.T.)Labatt Brain Tumour Research Centre (V.R., D.S., M.R., E.B., M.D.T.)Department of Laboratory Medicine and Pathobiology (V.S., D.S., M.R., M.D.T.), University of Toronto, Toronto, Ontario, Canada
| | - A S Achrol
- Department of Neurosurgery (A.S.A., K.C.)
| | - K Chao
- Department of Neurosurgery (A.S.A., K.C.)
| | - T T Liu
- Department of Radiology (T.T.L.)
| | - D Shih
- Division of Neurosurgery (V.R., D.S., M.R., M.D.T.)Labatt Brain Tumour Research Centre (V.R., D.S., M.R., E.B., M.D.T.)Department of Laboratory Medicine and Pathobiology (V.S., D.S., M.R., M.D.T.), University of Toronto, Toronto, Ontario, Canada
| | - M Remke
- Division of Neurosurgery (V.R., D.S., M.R., M.D.T.)Labatt Brain Tumour Research Centre (V.R., D.S., M.R., E.B., M.D.T.)Department of Laboratory Medicine and Pathobiology (V.S., D.S., M.R., M.D.T.), University of Toronto, Toronto, Ontario, Canada
| | - S Schubert
- From the Department of Neurology (S. Perreault, S.S., P.G.F., S. Partap, Y.J.C.), Division of Child Neurology
| | - E Bouffet
- Labatt Brain Tumour Research Centre (V.R., D.S., M.R., E.B., M.D.T.)Division of Pediatric Hematology/Oncology (E.B), Hospital for Sick Children, Toronto, Ontario, Canada
| | - P G Fisher
- From the Department of Neurology (S. Perreault, S.S., P.G.F., S. Partap, Y.J.C.), Division of Child Neurology
| | - S Partap
- From the Department of Neurology (S. Perreault, S.S., P.G.F., S. Partap, Y.J.C.), Division of Child Neurology
| | - H Vogel
- Richard M. Lucas Center for Imaging, and Department of Pathology (H.V.), Stanford University, Stanford, California
| | - M D Taylor
- Division of Neurosurgery (V.R., D.S., M.R., M.D.T.)Labatt Brain Tumour Research Centre (V.R., D.S., M.R., E.B., M.D.T.)Department of Laboratory Medicine and Pathobiology (V.S., D.S., M.R., M.D.T.), University of Toronto, Toronto, Ontario, Canada
| | - Y J Cho
- From the Department of Neurology (S. Perreault, S.S., P.G.F., S. Partap, Y.J.C.), Division of Child Neurology
| | - K W Yeom
- Department of Radiology (K.W.Y.), Lucile Packard Children's Hospital at Stanford University, Palo Alto, California
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Holdsworth SJ, Yeom KW, Antonucci MU, Andre JB, Rosenberg J, Aksoy M, Straka M, Fischbein NJ, Bammer R, Moseley ME, Zaharchuk G, Skare S. Diffusion-weighted imaging with dual-echo echo-planar imaging for better sensitivity to acute stroke. AJNR Am J Neuroradiol 2014; 35:1293-302. [PMID: 24763417 DOI: 10.3174/ajnr.a3921] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND AND PURPOSE Parallel imaging facilitates the acquisition of echo-planar images with a reduced TE, enabling the incorporation of an additional image at a later TE. Here we investigated the use of a parallel imaging-enhanced dual-echo EPI sequence to improve lesion conspicuity in diffusion-weighted imaging. MATERIALS AND METHODS Parallel imaging-enhanced dual-echo DWI data were acquired in 50 consecutive patients suspected of stroke at 1.5T. The dual-echo acquisition included 2 EPI for 1 diffusion-preparation period (echo 1 [TE = 48 ms] and echo 2 [TE = 105 ms]). Three neuroradiologists independently reviewed the 2 echoes by using the routine DWI of our institution as a reference. Images were graded on lesion conspicuity, diagnostic confidence, and image quality. The apparent diffusion coefficient map from echo 1 was used to validate the presence of acute infarction. Relaxivity maps calculated from the 2 echoes were evaluated for potential complementary information. RESULTS Echo 1 and 2 DWIs were rated as better than the reference DWI. While echo 1 had better image quality overall, echo 2 was unanimously favored over both echo 1 and the reference DWI for its high sensitivity in detecting acute infarcts. CONCLUSIONS Parallel imaging-enhanced dual-echo diffusion-weighted EPI is a useful method for evaluating lesions with reduced diffusivity. The long TE of echo 2 produced DWIs that exhibited superior lesion conspicuity compared with images acquired at a shorter TE. Echo 1 provided higher SNR ADC maps for specificity to acute infarction. The relaxivity maps may serve to complement information regarding blood products and mineralization.
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Affiliation(s)
- S J Holdsworth
- From the Department of Radiology (S.J.H., K.W.Y., M.U.A., J.R., M.A., M.S., N.J.F., R.B., M.E.M., G.Z.), Stanford University, Stanford, California
| | - K W Yeom
- From the Department of Radiology (S.J.H., K.W.Y., M.U.A., J.R., M.A., M.S., N.J.F., R.B., M.E.M., G.Z.), Stanford University, Stanford, California
| | - M U Antonucci
- From the Department of Radiology (S.J.H., K.W.Y., M.U.A., J.R., M.A., M.S., N.J.F., R.B., M.E.M., G.Z.), Stanford University, Stanford, California
| | - J B Andre
- Department of Radiology (J.B.A.), University of Washington, Seattle, Washington
| | - J Rosenberg
- From the Department of Radiology (S.J.H., K.W.Y., M.U.A., J.R., M.A., M.S., N.J.F., R.B., M.E.M., G.Z.), Stanford University, Stanford, California
| | - M Aksoy
- From the Department of Radiology (S.J.H., K.W.Y., M.U.A., J.R., M.A., M.S., N.J.F., R.B., M.E.M., G.Z.), Stanford University, Stanford, California
| | - M Straka
- From the Department of Radiology (S.J.H., K.W.Y., M.U.A., J.R., M.A., M.S., N.J.F., R.B., M.E.M., G.Z.), Stanford University, Stanford, California
| | - N J Fischbein
- From the Department of Radiology (S.J.H., K.W.Y., M.U.A., J.R., M.A., M.S., N.J.F., R.B., M.E.M., G.Z.), Stanford University, Stanford, California
| | - R Bammer
- From the Department of Radiology (S.J.H., K.W.Y., M.U.A., J.R., M.A., M.S., N.J.F., R.B., M.E.M., G.Z.), Stanford University, Stanford, California
| | - M E Moseley
- From the Department of Radiology (S.J.H., K.W.Y., M.U.A., J.R., M.A., M.S., N.J.F., R.B., M.E.M., G.Z.), Stanford University, Stanford, California
| | - G Zaharchuk
- From the Department of Radiology (S.J.H., K.W.Y., M.U.A., J.R., M.A., M.S., N.J.F., R.B., M.E.M., G.Z.), Stanford University, Stanford, California
| | - S Skare
- Clinical Neuroscience (S.S.), Karolinska Institute, Stockholm, Sweden
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15
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Perreault S, Lober RM, Cheshier S, Partap S, Edwards MS, Yeom KW. Time-dependent structural changes of the dentatothalamic pathway in children treated for posterior fossa tumor. AJNR Am J Neuroradiol 2014; 35:803-7. [PMID: 24052507 DOI: 10.3174/ajnr.a3735] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Injury to the dentatothalamic pathway that originates in the cerebellum has been suggested as a mechanism for neurologic complications in children treated for posterior fossa tumors. We hypothesized that time-dependent changes occur in the dentatothalamic pathway. MATERIALS AND METHODS Diffusion tensor evaluation was performed in 14 children (median age, 4.1 years; age range, 1-20 years) who underwent serial MR imaging at 3T as part of routine follow-up after posterior fossa tumor resection with or without adjuvant therapy. Tensor metrics were obtained in the acute (≤1 week), subacute (1 to <6 months), and chronic (≥6 months) periods after surgery. We evaluated the following dentatothalamic constituents: bilateral dentate nuclei, cerebellar white matter, and superior cerebellar peduncles. Serial dentate nuclei volumes were also obtained and compared with the patient's baseline. RESULTS The most significant tensor changes to the superior cerebellar peduncles and cerebellar white matter occurred in the subacute period, regardless of the tumor pathology or therapy regimen, with signs of recovery in the chronic period. However, chronic volume loss and reduced mean diffusivity were observed in the dentate nuclei and did not reverse. This atrophy was associated with radiation therapy and symptoms of ataxia. CONCLUSIONS Longitudinal diffusion MR imaging in children treated for posterior fossa tumors showed time-dependent tensor changes in components of the dentatothalamic pathway that suggest evolution of structural damage with inflammation and recovery of tissue directionality. However, the dentate nuclei did not show tensor or volumetric recovery, suggesting that the injury may be chronic.
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Affiliation(s)
- S Perreault
- From the Departments of Neurology (S. Perreault, S. Partap)
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16
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Soman S, Holdsworth SJ, Barnes PD, Rosenberg J, Andre JB, Bammer R, Yeom KW. Improved T2* imaging without increase in scan time: SWI processing of 2D gradient echo. AJNR Am J Neuroradiol 2013; 34:2092-7. [PMID: 23744690 DOI: 10.3174/ajnr.a3595] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND AND PURPOSE 2D gradient-echo imaging is sensitive to T2* lesions (hemorrhages, mineralization, and vascular lesions), and susceptibility-weighted imaging is even more sensitive, but at the cost of additional scan time (SWI: 5-10 minutes; 2D gradient-echo: 2 minutes). The long acquisition time of SWI may pose challenges in motion-prone patients. We hypothesized that 2D SWI/phase unwrapped images processed from 2D gradient-echo imaging could improve T2* lesion detection. MATERIALS AND METHODS 2D gradient-echo brain images of 50 consecutive pediatric patients (mean age, 8 years) acquired at 3T were retrospectively processed to generate 2D SWI/phase unwrapped images. The 2D gradient-echo and 2D SWI/phase unwrapped images were compared for various imaging parameters and were scored in a blinded fashion. RESULTS Of 50 patients, 2D gradient-echo imaging detected T2* lesions in 29 patients and had normal findings in 21 patients. 2D SWI was more sensitive than standard 2D gradient-echo imaging in detecting T2* lesions (P < .0001). 2D SWI/phase unwrapped imaging also improved delineation of normal venous structures and nonpathologic calcifications and helped distinguish calcifications from hemorrhage. A few pitfalls of 2D SWI/phase unwrapped imaging were noted, including worsened motion and dental artifacts and challenges in detecting T2* lesions adjacent to calvaria or robust deoxygenated veins. CONCLUSIONS 2D SWI and associated phase unwrapped images processed from standard 2D gradient-echo images were more sensitive in detecting T2* lesions and delineating normal venous structures and nonpathologic mineralization, and they also helped distinguish calcification at no additional scan time. SWI processing of 2D gradient-echo images may be a useful adjunct in cases in which longer scan times of 3D SWI are difficult to implement.
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Affiliation(s)
- S Soman
- Department of Radiology, Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
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17
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Yeom KW, Lober RM, Barnes PD, Campen CJ. Reduced cerebral arterial spin-labeled perfusion in children with neurofibromatosis type 1. AJNR Am J Neuroradiol 2013; 34:1823-8. [PMID: 23764727 DOI: 10.3174/ajnr.a3649] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Neurofibromatosis type 1 is associated with increased risk for stroke, cerebral vasculopathy, and neurocognitive deficits, but underlying hemodynamic changes in asymptomatic children remain poorly understood. We hypothesized that children with neurofibromatosis type 1 have decreased cerebral blood flow. MATERIALS AND METHODS Arterial spin-labeled CBF was measured in 14 children with neurofibromatosis type 1 (median age, 9.7 years; mean, 10.2 years; range, 22 months to 18 years) and compared with age-matched control subjects on 3T MR imaging. Three-dimensional pseudocontinuous spin-echo arterial spin-labeled technique was used. Measurements were obtained at cortical gray matter of bilateral cerebral hemispheres and centrum semiovale by use of the ROI method. Comparison by Mann-Whitney test was used, with Bonferroni-adjusted P values ≤.004 judged as significant. RESULTS We identified 7 of 12 areas with significantly diminished arterial spin-labeled CBF in patients with neurofibromatosis type 1 compared with control subjects. These areas included the anterior cingulate gyrus (P = .001), medial frontal cortex (P = .004), centrum semiovale (P = .004), temporo-occipital cortex (P = .002), thalamus (P = .001), posterior cingulate gyrus (P = .002), and occipital cortex (P = .001). Among patients with neurofibromatosis type 1, there were no significant differences in these regions on the basis of the presence of neurofibromatosis type 1 spots or neurocognitive deficits. CONCLUSIONS Reduced cerebral perfusion was seen in children with neurofibromatosis type 1, particularly in the posterior circulation and the vascular borderzones of the middle and posterior cerebral arteries.
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Yeom KW, Mitchell LA, Lober RM, Barnes PD, Vogel H, Fisher PG, Edwards MS. Arterial spin-labeled perfusion of pediatric brain tumors. AJNR Am J Neuroradiol 2013; 35:395-401. [PMID: 23907239 DOI: 10.3174/ajnr.a3670] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Pediatric brain tumors have diverse pathologic features, which poses diagnostic challenges. Although perfusion evaluation of adult tumors is well established, hemodynamic properties are not well characterized in children. Our goal was to apply arterial spin-labeling perfusion for various pathologic types of pediatric brain tumors and evaluate the role of arterial spin-labeling in the prediction of tumor grade. MATERIALS AND METHODS Arterial spin-labeling perfusion of 54 children (mean age, 7.5 years; 33 boys and 21 girls) with treatment-naive brain tumors was retrospectively evaluated. The 3D pseudocontinuous spin-echo arterial spin-labeling technique was acquired at 3T MR imaging. Maximal relative tumor blood flow was obtained by use of the ROI method and was compared with tumor histologic features and grade. RESULTS Tumors consisted of astrocytic (20), embryonal (11), ependymal (3), mixed neuronal-glial (8), choroid plexus (5), craniopharyngioma (4), and other pathologic types (3). The maximal relative tumor blood flow of high-grade tumors (grades III and IV) was significantly higher than that of low-grade tumors (grades I and II) (P < .001). There was a wider relative tumor blood flow range among high-grade tumors (2.14 ± 1.78) compared with low-grade tumors (0.60 ± 0.29) (P < .001). Across the cohort, relative tumor blood flow did not distinguish individual histology; however, among posterior fossa tumors, relative tumor blood flow was significantly higher for medulloblastoma compared with pilocytic astrocytoma (P = .014). CONCLUSIONS Characteristic arterial spin-labeling perfusion patterns were seen among diverse pathologic types of brain tumors in children. Arterial spin-labeling perfusion can be used to distinguish high-grade and low-grade tumors.
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Affiliation(s)
- K W Yeom
- From the Departments of Radiology (K.W.Y., L.A.M., P.D.B.)
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Yeom KW, Lober RM, Mobley BC, Harsh G, Vogel H, Allagio R, Pearson M, Edwards MSB, Fischbein NJ. Diffusion-weighted MRI: distinction of skull base chordoma from chondrosarcoma. AJNR Am J Neuroradiol 2012; 34:1056-61, S1. [PMID: 23124635 DOI: 10.3174/ajnr.a3333] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Chordoma and chondrosarcoma of the skull base are rare tumors with overlapping presentations and anatomic imaging features but different prognoses. We hypothesized that these tumors might be distinguished by using diffusion-weighted MR imaging. MATERIALS AND METHODS We retrospectively reviewed 19 patients with pathologically confirmed chordoma or chondrosarcoma who underwent both conventional and diffusion-weighted MR imaging. Differences in distributions of ADC were assessed by the Kruskal-Wallis test. Associations between histopathologic diagnosis and conventional MR imaging features (T2 signal intensity, contrast enhancement, and tumor location) were assessed with the Fisher exact test. RESULTS Chondrosarcoma was associated with the highest mean ADC value (2051 ± 261 × 10(-6) mm(2)/s) and was significantly different from classic chordoma (1474 ± 117 × 10(-6) mm(2)/s) and poorly differentiated chordoma (875 ± 100 × 10(-6) mm(2)/s) (P < .001). Poorly differentiated chordoma was characterized by low T2 signal intensity (P = .001), but other conventional MR imaging features of enhancement and/or lesion location did not reliably distinguish these tumor types. CONCLUSIONS Diffusion-weighted MR imaging may be useful in assessing clival tumors, particularly in differentiating chordoma from chondrosarcoma. A prospective study of a larger cohort will be required to determine the value of ADC in predicting histopathologic diagnosis.
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Affiliation(s)
- K W Yeom
- Department of Radiology, Stanford University, Palo Alto, California 94304, USA.
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Bluml S, Panigrahy A, Laskov M, Dhall G, Nelson MD, Finlay JL, Gilles FH, Arita H, Kinoshita M, Kagawa N, Fujimoto Y, Hashimoto N, Yoshimine T, Kinoshita M, Arita H, Kagawa N, Fujimoto Y, Hashimoto N, Yoshimine T, Hamilton JD, Wang J, Levin VA, Hou P, Loghin ME, Gilbert MR, Leeds NE, deGroot JF, Puduvalli V, Jackson EF, Yung WKA, Kumar AJ, Ellingson BM, Cloughesy TF, Pope WB, Zaw T, Phillips H, Lalezari S, Nghiemphu PL, Ibrahim H, Motevalibashinaeini K, Lai A, Ellingson BM, Cloughesy TF, Zaw T, Harris R, Lalezari S, Nghiemphu PL, Motevalibashinaeini K, Lai A, Pope WB, Douw L, Van de Nieuwenhuijzen ME, Heimans JJ, Baayen JC, Stam CJ, Reijneveld JC, Juhasz C, Mittal S, Altinok D, Robinette NL, Muzik O, Chakraborty PK, Barger GR, Ellingson BM, Cloughesy TF, Zaw TM, Lalezari S, Nghiemphu PL, Motevalibashinaeini K, Lai A, Goldin J, Pope WB, Ellingson BM, Cloughesy TF, Harris R, Pope WB, Nghiemphu PL, Lai A, Zaw T, Chen W, Ahlman MA, Giglio P, Kaufmann TJ, Anderson SK, Jaeckle KA, Uhm JH, Northfelt DW, Flynn PJ, Buckner JC, Galanis E, Zalatimo O, Weston C, Allison D, Bota D, Kesari S, Glantz M, Sheehan J, Harbaugh RE, Chiba Y, Kinoshita M, Kagawa N, Fujimoto Y, Tsuboi A, Hatazawa J, Sugiyama H, Hashimoto N, Yoshimine T, Nariai T, Toyohara J, Tanaka Y, Inaji M, Aoyagi M, Yamamoto M, Ishiwara K, Ohno K, Jalilian L, Essock-Burns E, Cha S, Chang S, Prados M, Butowski N, Nelson S, Kawahara Y, Nakada M, Hayashi Y, Kai Y, Hayashi Y, Uchiyama N, Kuratsu JI, Hamada JI, Yeom K, Rosenberg J, Andre JB, Fisher PG, Edwards MS, Barnes PD, Partap S, Essock-Burns E, Jalilian L, Lupo JM, Crane JC, Cha S, Chang SM, Nelson SJ, Romanowski CA, Hoggard N, Jellinek DA, Clenton S, McKevitt F, Wharton S, Craven I, Buller A, Waddle C, Bigley J, Wilkinson ID, Metherall P, Eckel LJ, Keating GF, Wetjen NM, Giannini C, Wetmore C, Jain R, Narang J, Arbab AS, Schultz L, Scarpace L, Mikkelsen T, Babajni-Feremi A, Jain R, Poisson L, Narang J, Scarpace L, Gutman D, Jaffe C, Saltz J, Flanders A, Daniel B, Mikkelsen T, Zach L, Guez D, Last D, Daniels D, Hoffman C, Mardor Y, Guha-Thakurta N, Debnam JM, Kotsarini C, Wilkinson ID, Jellinek D, Griffiths PD, Khandanpour N, Hoggard N, Kotsarini C, Wilkinson ID, Jellinek D, Griffiths PD, Bambrough P, Hoggard N, Hamilton JD, Levin VA, Hou P, Prabhu S, Loghin ME, Gilbert MR, Bassett RL, Wang J, Yung WA, Jackson EF, Kumar AJ, Campen CJ, Soman S, Fisher PG, Edwards MS, Yeom KW, Vos MJ, Berkhof J, Postma TJ, Sanchez E, Sizoo EM, Heimans JJ, Lagerwaard FJ, Buter J, Noske DP, Reijneveld JC, Colen RR, Mahajan B, Jolesz FA, Zinn PO, Lupo JM, Molinaro A, Chang S, Lawton K, Cha S, Nelson SJ, Alexandru D, Bota D, Linskey ME, Chaumeil MM, Gini B, Yang H, Iwanami A, Subramanian S, Ozawa T, Read EJ, Pieper RO, Mischel P, James CD, Ronen SM, LaViolette PS, Cochran E, Al-Gizawiy M, Connelly JM, Malkin MG, Rand SD, Mueller WM, Schmainda KM, LaViolette PS, Cohen AD, Cochran E, Prah M, Hartman CJ, Connelly JM, Rand SD, Malkin MG, Mueller WM, Schmainda KM, Qiao XJ, He R, Brown M, Goldin J, Cloughesy T, Pope WB. RADIOLOGY. Neuro Oncol 2011; 13:iii136-iii144. [PMCID: PMC3222969 DOI: 10.1093/neuonc/nor162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023] Open
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