Non-contrast Dual-energy CT Using X-map for Acute Ischemic Stroke: Region-specific Comparison with Simulated 120-kVp CT and Diffusion-weighted MR Images

Overview

Journal Jpn J Radiol

Publisher Springer

Specialty Radiology

Date 2023 Sep 26

PMID 37750952

Authors

Yuki Shinohara

Tomomi Ohmura

Masanobu Ibaraki

Toshihide Itoh

Fumiaki Sasaki

Yuichiro Sato

Takato Inomata

Kanata Anbo

Toshibumi Kinoshita

Affiliations

Soon will be listed here.

Abstract

Purpose: X-map is a non-contrast dual-energy CT (DECT) application to identify acute ischemic stroke (AIS). Our aim was to verify region-specific characteristics of early ischemic changes (EIC) on X-map compared with simulated 120-kVp mixed-CT image and DWI.

Methods: Fifty AIS patients who underwent DECT and DWI were enrolled (mean age, 76 years; 34 men, 16 women). All datasets including mixed-CT image, X-map, and DWI were transformed into a standard brain atlas with 11 × 2 ROIs based on the ASPECTS + W system. ROIs with EIC on DWI, mixed-CT image, and X-map were defined as DWI-positive, mixed-CT-positive, and X-map-positive, and those with normal finding were DWI-negative, mixed-CT-negative, and X-map-negative respectively, in visual assessment by two neuroradiologists in consensus.

Results: EIC on X-maps were visually relevant to those on the other images: of 221 ROIs with mixed-CT-positive and X-map-positive, 198 (89.6%) were DWI-positive. X-map revealed moderate diagnostic accuracy for AIS compared with DWI in ROC curve analysis (AUC = 0.732). X-map identified EIC in deep white matter more sensitively than mixed-CT image: of 15 ROIs with mixed-CT-negative and X-map-positive in W segments, 14 (93.3%) were DWI-positive. X-map often showed EIC in cortical regions that were not detected on the other images: of 67 ROIs with mixed-CT-negative and X-map-positive in I and M1-M6 segments, 47 (70.1%) were DWI-negative.

Conclusions: X-map is useful to detect EIC, especially in deep white matter, and may also provide additional information in acute ischemic lesions where DWI cannot be detected.

Citing Articles

Arrival time mapping with O-gas PET for cerebrovascular steno-occlusive diseases: a comparative study with CT perfusion.

Ibaraki M, Shinohara Y, Watanabe A, Sato K, Ohmura T, Yamamoto H EJNMMI Res. 2025; 15(1):20.

PMID: 40055252 PMC: 11889313. DOI: 10.1186/s13550-025-01209-7.

References

Saver J, Goyal M, Bonafe A, Diener H, Levy E, Pereira V . Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke. N Engl J Med. 2015; 372(24):2285-95. DOI: 10.1056/NEJMoa1415061. View

Primak A, Giraldo J, Eusemann C, Schmidt B, Kantor B, Fletcher J . Dual-source dual-energy CT with additional tin filtration: Dose and image quality evaluation in phantoms and in vivo. AJR Am J Roentgenol. 2010; 195(5):1164-74. PMC: 2963033. DOI: 10.2214/AJR.09.3956. View

Graser A, Johnson T, Chandarana H, Macari M . Dual energy CT: preliminary observations and potential clinical applications in the abdomen. Eur Radiol. 2008; 19(1):13-23. DOI: 10.1007/s00330-008-1122-7. View

Unger E, Littlefield J, Gado M . Water content and water structure in CT and MR signal changes: possible influence in detection of early stroke. AJNR Am J Neuroradiol. 1988; 9(4):687-91. PMC: 8332013. View

Mohammed M, Marais O, Min A, Ferguson D, Jalal S, Khosa F . Unenhanced Dual-Energy Computed Tomography: Visualization of Brain Edema. Invest Radiol. 2017; 53(2):63-69. DOI: 10.1097/RLI.0000000000000413. View

Goyal M, Demchuk A, Menon B, Eesa M, Rempel J, Thornton J . Randomized assessment of rapid endovascular treatment of ischemic stroke. N Engl J Med. 2015; 372(11):1019-30. DOI: 10.1056/NEJMoa1414905. View

Wolman D, Van Ommen F, Tong E, Kauw F, Dankbaar J, Bennink E . Non-contrast dual-energy CT virtual ischemia maps accurately estimate ischemic core size in large-vessel occlusive stroke. Sci Rep. 2021; 11(1):6745. PMC: 7991428. DOI: 10.1038/s41598-021-85143-3. View

Grams A, Djurdjevic T, Rehwald R, Schiestl T, Dazinger F, Steiger R . Improved visualisation of early cerebral infarctions after endovascular stroke therapy using dual-energy computed tomography oedema maps. Eur Radiol. 2018; 28(11):4534-4541. PMC: 6182745. DOI: 10.1007/s00330-018-5449-4. View

Naruto N, Itoh T, Noguchi K . Dual energy computed tomography for the head. Jpn J Radiol. 2017; 36(2):69-80. DOI: 10.1007/s11604-017-0701-4. View

10.

Itoh T, Noguchi K . Evaluation of the quantitative performance of non-enhanced dual-energy CT X-map in detecting acute ischemic brain stroke: A model observer study using computer simulation. Phys Med. 2022; 104:85-92. DOI: 10.1016/j.ejmp.2022.10.025. View

11.

Poirot M, Bergmans R, Thomson B, Jolink F, Moum S, Gonzalez R . Physics-informed Deep Learning for Dual-Energy Computed Tomography Image Processing. Sci Rep. 2019; 9(1):17709. PMC: 6881337. DOI: 10.1038/s41598-019-54176-0. View

12.

Kuhl C, Textor J, Gieseke J, von Falkenhausen M, Gernert S, Urbach H . Acute and subacute ischemic stroke at high-field-strength (3.0-T) diffusion-weighted MR imaging: intraindividual comparative study. Radiology. 2004; 234(2):509-16. DOI: 10.1148/radiol.2342031323. View

13.

Noguchi K, Itoh T, Naruto N, Takashima S, Tanaka K, Kuroda S . A Novel Imaging Technique (X-Map) to Identify Acute Ischemic Lesions Using Noncontrast Dual-Energy Computed Tomography. J Stroke Cerebrovasc Dis. 2016; 26(1):34-41. DOI: 10.1016/j.jstrokecerebrovasdis.2016.08.025. View

14.

Berkhemer O, Fransen P, Beumer D, van den Berg L, Lingsma H, Yoo A . A randomized trial of intraarterial treatment for acute ischemic stroke. N Engl J Med. 2014; 372(1):11-20. DOI: 10.1056/NEJMoa1411587. View

15.

Kawano H, Hirano T, Inatomi Y, Terasaki T, Yonehara T, Uchino M . Presence of deep white matter lesions on diffusion-weighted imaging is a negative predictor of early dramatic improvement after intravenous tissue plasminogen activator thrombolysis. Cerebrovasc Dis. 2010; 30(3):230-6. DOI: 10.1159/000317183. View

16.

Brooks R, DI CHIRO G, Keller M . Explanation of cerebral white--gray contrast in computed tomography. J Comput Assist Tomogr. 1980; 4(4):489-91. DOI: 10.1097/00004728-198008000-00016. View

17.

Campbell B, Mitchell P, Kleinig T, Dewey H, Churilov L, Yassi N . Endovascular therapy for ischemic stroke with perfusion-imaging selection. N Engl J Med. 2015; 372(11):1009-18. DOI: 10.1056/NEJMoa1414792. View

18.

Schaefer P, Grant P, Gonzalez R . Diffusion-weighted MR imaging of the brain. Radiology. 2000; 217(2):331-45. DOI: 10.1148/radiology.217.2.r00nv24331. View

19.

von Kummer R, Bourquain H, Bastianello S, Bozzao L, Manelfe C, Meier D . Early prediction of irreversible brain damage after ischemic stroke at CT. Radiology. 2001; 219(1):95-100. DOI: 10.1148/radiology.219.1.r01ap0695. View

20.

Barber P, Demchuk A, Zhang J, Buchan A . Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy. ASPECTS Study Group. Alberta Stroke Programme Early CT Score. Lancet. 2000; 355(9216):1670-4. DOI: 10.1016/s0140-6736(00)02237-6. View