An extract showing the Choice Group control you can use in SPFx web part properties (from getPropertyPaneConfiguration() method) - used here with images.

SPFxWebPartProperty_ChoiceGroup_WithImages.ts

PropertyPaneChoiceGroup('FileType', {
   label: 'File type:',
   options: [
    { key: 'Word', text: 'Word',
      imageSrc: 'https://static2.sharepointonline.com/files/fabric/assets/brand-icons/document/png/docx_32x1.png',
      imageSize: { width: 32, height: 32 },
      selectedImageSrc: 'https://static2.sharepointonline.com/files/fabric/assets/brand-icons/document/png/docx_32x1.png'
    },
    { key: 'Excel', text: 'Excel',
      imageSrc: 'https://static2.sharepointonline.com/files/fabric/assets/brand-icons/document/png/xlsx_32x1.png',
      imageSize: { width: 32, height: 32 },
      selectedImageSrc: 'https://static2.sharepointonline.com/files/fabric/assets/brand-icons/document/png/xlsx_32x1.png'
    },
    { key: 'PowerPoint', text: 'PowerPoint',
      imageSrc: 'https://static2.sharepointonline.com/files/fabric/assets/brand-icons/document/png/pptx_32x1.png',
      imageSize: { width: 32, height: 32 },
      selectedImageSrc: 'https://static2.sharepointonline.com/files/fabric/assets/brand-icons/document/png/pptx_32x1.png'
    },
    { key: 'OneNote', text: 'OneNote',
      imageSrc: 'https://static2.sharepointonline.com/files/fabric/assets/brand-icons/document/png/one_32x1.png',
      imageSize: { width: 32, height: 32 },
      selectedImageSrc: 'https://static2.sharepointonline.com/files/fabric/assets/brand-icons/document/png/one_32x1.png'
    }
  ]
})