We can use [(ngModel)] in following way and have a value selection variable radioSelected
Example tutorial
Demo Link
app.component.html
  <div class="text-center mt-5">
  <h4>Selected value is {{radioSel.name}}</h4>
  <div>
    <ul class="list-group">
          <li class="list-group-item"  *ngFor="let item of itemsList">
            <input type="radio" [(ngModel)]="radioSelected" name="list_name" value="{{item.value}}" (change)="onItemChange(item)"/> 
            {{item.name}}
          </li>
    </ul>
  </div>
  <h5>{{radioSelectedString}}</h5>
  </div>
app.component.ts
  import {Item} from '../app/item';
  import {ITEMS} from '../app/mock-data';
  @Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
  })
  export class AppComponent {
    title = 'app';
    radioSel:any;
    radioSelected:string;
    radioSelectedString:string;
    itemsList: Item[] = ITEMS;
      constructor() {
        this.itemsList = ITEMS;
        //Selecting Default Radio item here
        this.radioSelected = "item_3";
        this.getSelecteditem();
      }
      // Get row item from array  
      getSelecteditem(){
        this.radioSel = ITEMS.find(Item => Item.value === this.radioSelected);
        this.radioSelectedString = JSON.stringify(this.radioSel);
      }
      // Radio Change Event
      onItemChange(item){
        this.getSelecteditem();
      }
  }
Sample Data for Listing
        export const ITEMS: Item[] = [
            {
                name:'Item 1',
                value:'item_1'
            },
            {
                name:'Item 2',
                value:'item_2'
            },
            {
                name:'Item 3',
                value:'item_3'
            },
            {
                name:'Item 4',
                value:'item_4'
                },
                {
                    name:'Item 5',
                    value:'item_5'
                }
        ];