封面《ましろ色シンフォニー》

前言

之前师兄师姐的系统中展示医疗影像用的都是2D切片。这种方法会使得切片多，展示起来很丑陋且不够直观。因此一直想找一个3D的方案展示。这个时候找到了niivue库，所以在自己做的系统里面封装使用记录一下。

niivue

niivue是一个基于WebGL2的前端库，可以在Web页面展示NIFIT、DICOM等多种格式的医学影像并且提供一个3D的展示效果。官方Demo地址https://niivue.github.io/niivue-ui/

使用

因为我的系统是基于React+Ant Design Pro搭建，因此下面的工程都是基于React写，Vue可以看官方文档

安装&使用

1	npm install @niivue/niivue

官方使用文档如下

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8" />
  <meta http-equiv="X-UA-Compatible" content="IE=edge" />
  <meta name="viewport" content="width=device-width,initial-scale=1.0" />
  <title>NiiVue</title>
</head>
<body>
<div>
  <label>
    Show Orient Cube
    <input type="checkbox" checked id="cube-checkbox" />
  </label>
  <label>
    Ventricles Opacity
    <input type="range" min="0.0" max="1.0" step="0.1" value="0.5" id="opacity-slider"/>
  </label>
</div>
<div>
  <canvas id="gl1"></canvas>
</div>
<script type="module" async>
  import { Niivue } from "@niivue/niivue";
  const opacitySlider = document.getElementById('opacity-slider');
  const cubeCheckbox = document.getElementById('cube-checkbox');
  const nv = new Niivue();
  nv.attachTo("gl1");
  const volumes = [
    {
      url: 'https://fetalmri-hosting-of-medical-image-analysis-platform-dcb83b.apps.shift.nerc.mghpcc.org/api/v1/files/23/template.nii.gz',
    },
    {
      url: 'https://fetalmri-hosting-of-medical-image-analysis-platform-dcb83b.apps.shift.nerc.mghpcc.org/api/v1/files/49/ventricles.nii.gz',
      opacity: opacitySlider.value,
      colormap: 'red'
    }
  ];
  await nv.loadVolumes(volumes);
  opacitySlider.oninput = function() {
    nv.setOpacity(1, opacitySlider.value);
  }
  cubeCheckbox.oninput = function () {
    nv.opts.isOrientCube = cubeCheckbox.checked;
    nv.updateGLVolume();
  }
  cubeCheckbox.oninput();
</script>
</body>
</html>

封装

niivue本身很好用，但是组件中不含有图注，需要自己加，因此基于Antd的CheckedTag模块加上了一个图注。

这里面主要是使用canvas进行绘制，更新时在useEffect中对volumelist进行更新,useEffect监听volumelist和checktag的变化。完整代码如下

import { Niivue } from "@niivue/niivue";
import { Space, Tag, Tooltip } from "antd";
import _ from "lodash";
import React, { useEffect, useRef, useState } from "react";

const { CheckableTag } = Tag;

export type Volume = {
  url: string;
  volume: { hdr: any; img: any };
  colorMap: string;
  opacity: number;
  visible: boolean;
  strokeType?: string;
};

export type NiiVueProps = {
  volumeList: Volume[];
};

export const NiiVue: React.FC<NiiVueProps> = ({ volumeList }: NiiVueProps) => {
  // 选择标签
  const [selectedTags, setSelectedTags] = useState<string[]>(
    _.compact(_.map(volumeList, "strokeType"))
  );
  // 画图ref
  const canvas = useRef();

  // 图注选择
  const handleChange = (tag: string, checked: boolean) => {
    const nextSelectedTags = checked
      ? [...selectedTags, tag]
      : selectedTags.filter((t) => t !== tag);
    console.log("You are interested in: ", nextSelectedTags);
    setSelectedTags(nextSelectedTags);
  };

  useEffect(() => {
    if (!volumeList || volumeList.length === 0) {
      return;
    }
    // 选择要展示的volume
    let _volumeList = _.compact(
      _.map(volumeList, (volume) => {
        if (volume.strokeType) {
          if (_.includes(selectedTags, volume.strokeType)) {
            return {
              ...volume,
            };
          }
        } else {
          return volume;
        }
      })
    );
    const nv = new Niivue();
    nv.attachToCanvas(canvas.current);
    //console.log(_volumeList);
    nv.loadVolumes(_volumeList);
  }, [volumeList, selectedTags]);

  return (
    <>
      <div>
        <Space>
          {volumeList &&
            volumeList.length > 0 &&
            _.map(volumeList, (volume) => {
              if (volume.strokeType) {
                return (
                  <CheckableTag
                    style={{
                      backgroundColor: selectedTags.includes(volume.strokeType)
                        ? volume.colorMap
                        : "",
                    }}
                    key={volume.strokeType}
                    checked={selectedTags.includes(volume.strokeType)}
                    onChange={(checked) => {
                      handleChange(volume.strokeType, checked);
                    }}
                  >
                    {volume.strokeType}
                  </CheckableTag>
                );
              }
            })}
        </Space>
      </div>
      <div>
        <Tooltip title="按v键切换影像">
          <canvas ref={canvas} height={480} width={640} />
        </Tooltip>
      </div>
    </>
  );
};